U.S. patent application number 14/347946 was filed with the patent office on 2014-08-21 for humidity control apparatus.
The applicant listed for this patent is DAIKIN INDUSTRIES, LTD.. Invention is credited to Naotoshi Fujita, Nobuki Matsui, Eisaku Ohkubo, Tatsunori Tenpaku, Hiroki Ueda.
Application Number | 20140230475 14/347946 |
Document ID | / |
Family ID | 47994694 |
Filed Date | 2014-08-21 |
United States Patent
Application |
20140230475 |
Kind Code |
A1 |
Matsui; Nobuki ; et
al. |
August 21, 2014 |
HUMIDITY CONTROL APPARATUS
Abstract
A refrigerant circuit of a humidity control apparatus is
provided with two adsorption heat exchangers. In the refrigerant
circuit, refrigerant can circulate in reverse directions. A
switching mechanism of the humidity control apparatus switches
between a transfer path of the outdoor air to be supplied into a
room and a transfer path of the indoor air to be exhausted to the
outside the room. In a first operation of the humidity control
apparatus, a direction of refrigerant circulation and a flow path
of the air are changed every predetermined period. In a second
operation of the humidity control apparatus, the refrigerant
circuit is stopped, and the flow path of the air is changed every
predetermined period.
Inventors: |
Matsui; Nobuki; (Osaka,
JP) ; Ueda; Hiroki; (Osaka, JP) ; Ohkubo;
Eisaku; (Osaka, JP) ; Fujita; Naotoshi;
(Osaka, JP) ; Tenpaku; Tatsunori; (Shiga,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIKIN INDUSTRIES, LTD. |
Osaka-shi, Osaka |
|
JP |
|
|
Family ID: |
47994694 |
Appl. No.: |
14/347946 |
Filed: |
September 20, 2012 |
PCT Filed: |
September 20, 2012 |
PCT NO: |
PCT/JP2012/005988 |
371 Date: |
March 27, 2014 |
Current U.S.
Class: |
62/186 ; 62/223;
62/271 |
Current CPC
Class: |
F24F 11/0008 20130101;
F24F 2140/50 20180101; F24F 3/1429 20130101 |
Class at
Publication: |
62/186 ; 62/271;
62/223 |
International
Class: |
F24F 11/00 20060101
F24F011/00; F24F 3/14 20060101 F24F003/14 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2011 |
JP |
2011-214912 |
Claims
1. A humidity control apparatus, comprising: a refrigerant circuit
which includes a compressor, and a first adsorption heat exchanger
and a second adsorption heat exchanger each carrying an adsorbent,
and which performs a first refrigeration cycle operation in which
the first adsorption heat exchanger serves as a radiator and the
second adsorption heat exchanger serves as an evaporator, and a
second refrigeration cycle operation in which the second adsorption
heat exchanger serves as a radiator and the first adsorption heat
exchanger serves as an evaporator; an air supply fan configured to
supply outdoor air to an indoor space; an exhaust fan configured to
exhaust indoor air to an outdoor space; and a switching mechanism
configured to switch a flow path of the air between a first path in
which the outdoor air passes through the first adsorption heat
exchanger and thereafter flows into the indoor space, and the
indoor air passes through the second adsorption heat exchanger and
is thereafter exhausted to the outdoor space, and a second path in
which the outdoor air passes through the second adsorption heat
exchanger and thereafter flows into the indoor space, and the
indoor air passes through the first adsorption heat exchanger and
is thereafter exhausted to the outdoor space, wherein the humidity
control apparatus performs a first operation in which the air
supply fan and the exhaust fan are actuated; the refrigerant
circuit alternately performs the first refrigeration cycle
operation and the second refrigeration cycle operation every
predetermined period of time; and the switching mechanism
alternately sets the flow path of the air to the first path and the
second path in conjunction with the alternate change of the
refrigeration cycle operation of the refrigerant circuit, thereby
dehumidifying or humidifying the outdoor air to be supplied to the
indoor space, and a second operation in which the air supply fan
and the exhaust fan are actuated; the compressor of the refrigerant
circuit is stopped; and the switching mechanism alternately sets
the flow path of the air to the first path and the second path
every predetermined period of time.
2. The humidity control apparatus of claim 1, further comprising: a
controller which controls an operation capacity of the compressor
according to a humidity control load during the first operation,
wherein the controller switches an operation of the humidity
control apparatus from the first operation to the second operation
if it is considered that even if the operation capacity of the
compressor is set to a minimum capacity during the first operation,
a humidity control capability is high relative to the humidity
control load, and the controller switches the operation of the
humidity control apparatus from the second operation to the first
operation if it is considered that the humidity control capability
is low relative to the humidity control load during the second
operation.
3. The humidity control apparatus of claim 1, wherein the
refrigerant circuit is provided with an expansion valve whose
degree of opening is variable, at a location between the first
adsorption heat exchanger and the second adsorption heat exchanger,
and the expansion valve is maintained in a fully open state during
the second operation.
4. The humidity control apparatus of claim 1, wherein a time
interval between switching operations of the switching mechanism
during the second operation, for alternately switching the flow
path of the air between the first path and the second path, is less
than or equal to a time interval between switching operations of
the switching mechanism during the first operation, for alternately
switching the flow path of the air between the first path and the
second path.
5. The humidity control apparatus of claim 2, wherein the
refrigerant circuit is provided with an expansion valve whose
degree of opening is variable, at a location between the first
adsorption heat exchanger and the second adsorption heat exchanger,
and the expansion valve is maintained in a fully open state during
the second operation.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to humidity control
apparatuses which dehumidify and humidify air using an adsorption
heat exchanger carrying an adsorbent.
BACKGROUND ART
[0002] Humidity control apparatuses which dehumidify or humidify
air using an adsorbent have been known. For example, Patent
Document 1 discloses a humidity control apparatus which has an
adsorption heat exchanger carrying an adsorbent.
[0003] In the humidity control apparatus of Patent Document 1, a
refrigerant circuit which performs a refrigeration cycle is
provided with two adsorption heat exchangers. The refrigerant
circuit performs a refrigeration cycle operation in which a first
adsorption heat exchanger serves as a radiator and a second
adsorption heat exchanger serves as an evaporator, and a
refrigeration cycle operation in which the second adsorption heat
exchanger serves as a radiator and the first adsorption heat
exchanger serves as an evaporator, alternately every predetermined
period (e.g., three minutes).
[0004] Further, the humidity control apparatus of Patent Document 1
ventilates indoor space. That is, the humidity control apparatus
supplies outdoor air to an indoor space, and exhausts indoor air to
an outdoor space. Specifically, the humidity control apparatus has
a plurality of dampers which can be opened and closed. The humidity
control apparatus switches a flow path of the air by opening and
closing the dampers. Specifically, the flow path of the air of the
humidity control apparatus is switched between a first path in
which the outdoor air is supplied to the indoor space after passing
through the first adsorption heat exchanger and in which the indoor
air is exhausted to the outdoor space after passing through the
second adsorption heat exchanger, and a second path in which the
outdoor air is supplied to the indoor space after passing through
the second adsorption heat exchanger and in which the indoor air is
exhausted to the outdoor space after passing through the first
adsorption heat exchanger.
[0005] In the humidity control apparatus of Patent Document 1, the
switching of the refrigeration cycle operations in the refrigerant
circuit and the switching of the flow path of the air are performed
in conjunction with each other. The humidity control apparatus in a
dehumidifying operation supplies the outdoor air dehumidified by
the adsorption heat exchanger serving as an evaporator to the
indoor space, and discharges the moisture desorbed from the
adsorption heat exchanger serving as a radiator to the outdoor
space together with the indoor air. The humidity control apparatus
in a humidifying operation supplies the outdoor air humidified by
the adsorption heat exchanger serving as a radiator to the indoor
space, and discharge the indoor air whose moisture is taken by the
adsorption heat exchanger serving as an evaporator, to the outdoor
space.
CITATION LIST
Patent Document
[0006] Patent Document 1: Japanese Unexamined Patent Publication
No. 2007-010231
SUMMARY OF THE INVENTION
Technical Problem
[0007] In a humidity control apparatus having such a refrigerant
circuit as disclosed in Patent Document 1, the humidity control
capability (i.e., a dehumidification amount and a humidification
amount per unit time) may sometimes be controlled. The humidity
control capability is controlled by adjusting operation capacity of
a compressor (specifically, rotating speed of the compressor).
[0008] However, the rotating speed of the compressor needs to be
maintained at a certain degree or more so that the compressor can
operate properly. That is, the adjustable range of the operation
capacity of the compressor has a lower limit, and it is impossible
to set the operation capacity of the compressor to be less than the
lower limit. For example, in the case where the lower limit of the
adjustable range of the operation capacity of the compressor is 20%
of the maximum capacity, it is impossible to set the operation
capacity of the compressor to be 10% of the maximum capacity. This
means that the humidity control capability cannot be set below a
certain lower limit in the humidity control apparatus having a
compressor.
[0009] Thus, in the conventional humidity control apparatus, the
compressor is stopped when the humidity control capability is
excessive even if the operation capacity of the compressor is set
to a minimum capacity. Further, in the humidity control apparatus
which does not only control humidity of air, but also ventilates
the indoor space, such as the apparatus disclosed in Patent
Document 1, the indoor space needs to be continuously ventilated
even in the state where the compressor is stopped. Thus, in the
conventional humidity control apparatus, if the humidity control
capability is excessive when the compressor is in operation, the
compressor is stopped, and supply of the outdoor air into the
indoor space and the exhaustion of the indoor air to the outdoor
space are continuously performed.
[0010] The conventional humidity control apparatus does not switch
the flow path of the air during the operation in which the
compressor is stopped and the ventilation is continuously
performed. Thus, during this operation, the outdoor air keeps
passing through one of the adsorption heat exchangers, and the
indoor air keeps passing through the other adsorption heat
exchanger. This means that the outdoor air is supplied to the
indoor space without control of temperature and humidity, which may
reduce comfort of the indoor space.
[0011] The present disclosure is therefore intended to control
temperature and humidity of air to be supplied to an indoor space
even when a refrigeration cycle operation of a refrigerant circuit
is stopped, and ensure comfort of the indoor space, in a humidity
control apparatus which has a refrigerant circuit to dehumidify and
humidify outdoor air to be supplied to the indoor space.
Solution to the Problem
[0012] The first aspect of the present disclosure is intended for a
humidity control apparatus. The humidity control apparatus
includes: a refrigerant circuit (50) which includes a compressor
(53), and a first adsorption heat exchanger (51) and a second
adsorption heat exchanger (52) each carrying an adsorbent, and
which performs a first refrigeration cycle operation in which the
first adsorption heat exchanger (51) serves as a radiator and the
second adsorption heat exchanger (52) serves as an evaporator, and
a second refrigeration cycle operation in which the second
adsorption heat exchanger (52) serves as a radiator and the first
adsorption heat exchanger (51) serves as an evaporator; an air
supply fan (26) configured to supply outdoor air to an indoor
space; an exhaust fan (25) configured to exhaust indoor air to an
outdoor space; and a switching mechanism (40) configured to switch
a flow path of the air between a first path in which the outdoor
air passes through the first adsorption heat exchanger (51) and
thereafter flows into the indoor space, and the indoor air passes
through the second adsorption heat exchanger (52) and is thereafter
exhausted to the outdoor space, and a second path in which the
outdoor air passes through the second adsorption heat exchanger
(52) and thereafter flows into the indoor space, and the indoor air
passes through the first adsorption heat exchanger (51) and is
thereafter exhausted to the outdoor space, wherein the humidity
control apparatus performs a first operation in which the air
supply fan (26) and the exhaust fan (25) are actuated; the
refrigerant circuit (50) alternately performs the first
refrigeration cycle operation and the second refrigeration cycle
operation every predetermined period of time; and the switching
mechanism (40) alternately sets the flow path of the air to the
first path and the second path in conjunction with the alternate
change of the refrigeration cycle operation of the refrigerant
circuit (50), thereby dehumidifying or humidifying the outdoor air
to be supplied to the indoor space, and a second operation in which
the air supply fan (26) and the exhaust fan (25) are actuated; the
compressor (53) of the refrigerant circuit (50) is stopped; and the
switching mechanism (40) alternately sets the flow path of the air
to the first path and the second path every predetermined period of
time.
[0013] In the first aspect of the present disclosure, the humidity
control apparatus (10) performs the first operation and the second
operation. In the humidity control apparatus (10) in the first
operation, the compressor (53) of the refrigerant circuit (50) is
actuated, and the refrigerant circuit (50) alternately performs the
first refrigeration cycle operation and the second refrigeration
cycle operation. That is, in the refrigerant circuit (50), the
first refrigeration cycle operation and the second refrigeration
cycle operation are alternately performed every predetermined
period of time. In the adsorption heat exchanger (51, 52) serving
as a radiator, the adsorbent carried on the surface of the
adsorption heat exchanger (51, 52) is heated by the refrigerant,
and moisture is desorbed from the adsorbent. The moisture desorbed
from the adsorbent is given to the air passing through the
adsorption heat exchanger (51, 52). On the other hand, in the
adsorption heat exchanger (51, 52) serving as an evaporator,
moisture in the air passing through the adsorption heat exchanger
(51, 52) is adsorbed to the adsorbent. The refrigerant flowing in
the adsorption heat exchanger (51, 52) absorbs adsorption heat,
which is generated when the moisture in the air is adsorbed to the
adsorbent, and evaporates.
[0014] In the humidity control apparatus (10) in the first
operation, the switching mechanism (40) switches the flow path of
the air between the first path and the second path. The switching
mechanism (40) switches the flow path of the air in conjunction
with the alternate change of the refrigeration cycle operation of
the refrigerant circuit (50). That is, when the operation of the
refrigerant circuit (50) is switched from one to the other of the
first refrigeration cycle operation and the second refrigeration
cycle operation, the flow path of the air is switched from one to
the other of the first path and the second path.
[0015] In the humidity control apparatus (10) in the first
operation, dehumidified outdoor air is supplied to the indoor space
and humidified indoor air is exhausted to the outdoor space, when
the switching mechanism (40) sets the flow path of the air to the
second path in the first refrigeration cycle operation of the
refrigerant circuit (50), and the switching mechanism (40) sets the
flow path of the air to the first path in the second refrigeration
cycle operation of the refrigerant circuit (50). Further, in the
humidity control apparatus (10) in the first operation, humidified
outdoor air is supplied to the indoor space, and dehumidified
indoor air is exhausted to the outdoor space, when the switching
mechanism (40) sets the flow path of the air to the first path in
the first refrigeration cycle operation of the refrigerant circuit
(50), and the switching mechanism (40) sets the flow path of the
air to the second path in the second refrigeration cycle operation
of the refrigerant circuit (50).
[0016] According to the first aspect of the present disclosure, in
the humidity control apparatus (10) in the second operation, the
compressor (53) of the refrigerant circuit (50) is stopped, whereas
the air supply fan (26) and the exhaust fan (25) are continuously
actuated. During the second operation, as well, the switching
mechanism (40) alternately switches the flow path of the air
between the first path and the second path. Thus, the humidity
control apparatus (10) in the second operation alternately performs
an operation in which the outdoor air passes through the first
adsorption heat exchanger (51) and is thereafter supplied into the
indoor space, and the indoor air passes through the second
adsorption heat exchanger (52) and is thereafter exhausted to the
outdoor space, and an operation in which the outdoor air passes
through the second adsorption heat exchanger (52) and is thereafter
supplied into the indoor space, and the indoor air passes through
the first adsorption heat exchanger (51) and is thereafter
exhausted to the outdoor space.
[0017] First, of the second operation of the humidity control
apparatus (10), an example in which the temperature and the
absolute humidity of the outdoor air are slightly higher than those
of the indoor air (e.g., a case in which the room is cooled in late
spring or early autumn) will be described. In this case, the
humidity control apparatus (10) in the second operation cools and
dehumidifies the outdoor air to be supplied to the indoor space.
The mechanism will be described below.
[0018] A state in which the flow path of the air is set to the
first path will be described first. In this state, the outdoor air
passes through the first adsorption heat exchanger (51), and the
indoor air passes through the second adsorption heat exchanger
(52).
[0019] Even during a period when the compressor (53) is stopped,
the liquid refrigerant remains in the first adsorption heat
exchanger (51). When the outdoor air passes through the first
adsorption heat exchanger (51), the liquid refrigerant in the first
adsorption heat exchanger (51) absorbs the adsorption heat, which
is generated when the moisture in the outdoor air is adsorbed to
the adsorbent, and further absorbs heat from the outdoor air and
evaporates.
[0020] On the other hand, the indoor air whose temperature is lower
than the outdoor air flows in the second adsorption heat exchanger
(52). Thus, the refrigerant evaporated in the first adsorption heat
exchanger (51) flows into the second adsorption heat exchanger (52)
and is condensed. In the second adsorption heat exchanger (52), the
adsorbent is heated by heat of condensation dissipated from the
refrigerant, and moisture is desorbed from the adsorbent and is
given to the indoor air. In the second adsorption heat exchanger
(52), the heat transferred by the refrigerant from the first
adsorption heat exchanger (51) is dissipated into the indoor
air.
[0021] After that, the flow path of the air is switched from the
first path to the second path. That is, the air passing through the
first adsorption heat exchanger (51) is changed from the outdoor
air to the indoor air, and the air passing through the second
adsorption heat exchanger (52) is changed from the indoor air to
the outdoor air.
[0022] As described above, in the state where the flow path of the
air is set to the first path, moisture is desorbed from the
adsorbent in the second adsorption heat exchanger (52). Thus, after
the flow path of the air is switched to the second path, the
moisture contained in the outdoor air is adsorbed to the second
adsorption heat exchanger (52). The refrigerant in the second
adsorption heat exchanger (52) absorbs adsorption heat, which is
generated when the moisture in the outdoor air is adsorbed to the
adsorbent, and further absorbs heat from the outdoor air and
evaporates. Thus, the temperature and the absolute humidity of the
outdoor air passing through the second adsorption heat exchanger
(52) are reduced. As a result, the temperature and the absolute
humidity of the outdoor air become close to the temperature and the
absolute humidity of air in the indoor space.
[0023] On the other hand, the indoor air whose temperature is lower
than the temperature of the outdoor air flows in the first
adsorption heat exchanger (51). Thus, the refrigerant which has
evaporated in the second adsorption heat exchanger (52) flows into
the first adsorption heat exchanger (51) and is condensed. In the
first adsorption heat exchanger (51), the adsorbent is heated by
heat of condensation dissipated from the refrigerant, and moisture
is desorbed from the adsorbent. That is, in the first adsorption
heat exchanger (51), moisture in the outdoor air is adsorbed when
the flow path of the air is set to the first path, and the moisture
is released into the indoor air when the flow path of the air is
set to the second path. Further, in the first adsorption heat
exchanger (51), the heat transferred by the refrigerant from the
second adsorption heat exchanger (52) is dissipated into the indoor
air.
[0024] After that, in the humidity control apparatus (10) in the
second operation, the flow path of the air is switched from the
second path to the first path again. That is, the air passing
through the first adsorption heat exchanger (51) is changed from
the indoor air to the outdoor air, and the air passing through the
second adsorption heat exchanger (52) is changed from the outdoor
air to the indoor air. As described above, the outdoor air is
cooled and dehumidified in the first adsorption heat exchanger
(51). As a result, the temperature and the absolute humidity of the
outdoor air become close to the temperature and the absolute
humidity of the indoor space. Further, the second adsorption heat
exchanger (52) releases heat transferred by the refrigerant from
the first adsorption heat exchanger (51), and moisture adsorbed
when the flow path of the air is set to the second path, into the
indoor air.
[0025] Next, of the second operation of the humidity control
apparatus (10), an example in which the temperature and the
absolute humidity of the outdoor air are slightly lower than those
of the indoor air (e.g., a case in which the room is heated in
early spring or late autumn) will be described. In this case, the
humidity control apparatus (10) in the second operation heats and
humidifies the outdoor air to be supplied into the indoor space.
The mechanism will be described below.
[0026] A state in which the flow path of the air is set to the
first path will be described first. In this state, the outdoor air
passes through the first adsorption heat exchanger (51), and the
indoor air passes through the second adsorption heat exchanger
(52).
[0027] Even during a period when the compressor (53) is stopped,
the liquid refrigerant remains in the second adsorption heat
exchanger (52). When the indoor air passes through the second
adsorption heat exchanger (52), the liquid refrigerant in the
second adsorption heat exchanger (52) absorbs the adsorption heat,
which is generated when the moisture in the indoor air is adsorbed
to the adsorbent, and further absorbs heat from the indoor air and
evaporates.
[0028] On the other hand, the outdoor air whose temperature is
lower than the temperature of the indoor air flows in the first
adsorption heat exchanger (51). Thus, the refrigerant evaporated in
the second adsorption heat exchanger (52) flows into the first
adsorption heat exchanger (51) and is condensed. In the first
adsorption heat exchanger (51), the adsorbent is heated by heat of
condensation dissipated from the refrigerant, and moisture is
desorbed from the adsorbent and is given to the outdoor air. In the
first adsorption heat exchanger (51), the heat transferred by the
refrigerant from the second adsorption heat exchanger (52) is
dissipated into the outdoor air.
[0029] After that, the flow path of the air is switched from the
first path to the second path. That is, the air passing through the
first adsorption heat exchanger (51) is changed from the outdoor
air to the indoor air, and the air passing through the second
adsorption heat exchanger (52) is changed from the indoor air to
the outdoor air.
[0030] As described above, in the state where the flow path of the
air is set to the first path, moisture is desorbed from the
adsorbent in the first adsorption heat exchanger (51). Thus, after
the flow path of the air is switched to the second path, the
moisture contained in the indoor air is adsorbed to the first
adsorption heat exchanger (51). The refrigerant in the first
adsorption heat exchanger (51) absorbs adsorption heat, which is
generated when the moisture in the indoor air is adsorbed to the
adsorbent, and further absorbs heat from the indoor air and
evaporates.
[0031] On the other hand, the outdoor air whose temperature is
lower than the temperature of the indoor air flows in the second
adsorption heat exchanger (52). Thus, the refrigerant which has
evaporated in the first adsorption heat exchanger (51) flows into
the second adsorption heat exchanger (52) and is condensed. In the
second adsorption heat exchanger (52), the adsorbent is heated by
heat of condensation dissipated from the refrigerant, and moisture
is desorbed from the adsorbent. That is, in the second adsorption
heat exchanger (52), moisture in the indoor air is adsorbed when
the flow path of the air is set to the first path, and the moisture
is released into the outdoor air when the flow path of the air is
set to the second path. Further, in the second adsorption heat
exchanger (52), the heat transferred by the refrigerant from the
first adsorption heat exchanger (51) is dissipated into the outdoor
air. Thus, the temperature and the absolute humidity of the outdoor
air passing through the second adsorption heat exchanger (52) are
increased. As a result, the temperature and the absolute humidity
of the outdoor air become close to the temperature and the absolute
humidity of air in the indoor space.
[0032] After that, in the humidity control apparatus (10) in the
second operation, the flow path of the air is switched from the
second path to the first path again. That is, the air passing
through the first adsorption heat exchanger (51) is changed from
the indoor air to the outdoor air, and the air passing through the
second adsorption heat exchanger (52) is changed from the outdoor
air to the indoor air. As described above, in the second adsorption
heat exchanger (52), the adsorbent adsorbs the moisture in the
indoor air, and the refrigerant absorbs heat from the indoor air.
Further, in the first adsorption heat exchanger (51), the heat
transferred by the refrigerant from the second adsorption heat
exchanger (52) and moisture adsorbed when the flow path of the air
is set to the second path are given to the outdoor air. As a
result, the temperature and the absolute humidity of the outdoor
air become close to the temperature and the absolute humidity of
the indoor space.
[0033] As described above, even during the second operation where
the compressor (53) is stopped, the humidity control apparatus (10)
controls the temperature and the absolute humidity of the outdoor
air to be supplied to the indoor space. However, a flow rate of the
refrigerant which moves between the first adsorption heat exchanger
(51) and the second adsorption heat exchanger (52) in the
refrigerant circuit (50) in the second operation is lower than a
flow rate of the refrigerant which circulates in the refrigerant
circuit (50) in the first operation. Thus, the humidity control
properties of the humidity control apparatus (10) in the second
operation are lower than the humidity control properties of the
humidity control apparatus (10) in the first operation.
[0034] The second aspect of the present disclosure is that in the
first aspect of the present disclosure, the humidity control
apparatus further includes a controller (90) which controls an
operation capacity of the compressor (53) according to a humidity
control load during the first operation, wherein the controller
(90) switches an operation of the humidity control apparatus (10)
from the first operation to the second operation if it is
considered that even if the operation capacity of the compressor
(53) is set to a minimum capacity during the first operation, a
humidity control capability is high relative to the humidity
control load, and the controller (90) switches the operation of the
humidity control apparatus (10) from the second operation to the
first operation if it is considered that the humidity control
capability is low relative to the humidity control load during the
second operation.
[0035] In the second aspect of the present disclosure, the
controller (90) controls the operation capacity of the compressor
(53) according to the humidity control load. The humidity control
capability of the humidity control apparatus (10) changes when the
operation capacity of the compressor (53) is changed. The term
"humidity control load" means a dehumidification amount or a
humidification amount required of the humidity control apparatus
(10).
[0036] According to the second aspect of the present disclosure,
the controller (90) stops the compressor (53) and switches the
operation of the humidity control apparatus (10) to the second
operation when it determines that even if the operation capacity of
the compressor (53) is set to the minimum capacity in the first
operation, the humidity control capability is high relative to the
humidity control load. The humidity control capability of the
humidity control apparatus (10) in the second operation is lower
than the humidity control capability of the humidity control
apparatus (10) in the first operation at a time when the operation
capacity of the compressor (53) is set to the minimum capacity.
Further, the controller (90) actuates the compressor (53) and
switches the operation of the humidity control apparatus (10) to
the first operation when it determines that the humidity control
capability is low relative to the humidity control load in the
second operation.
[0037] The third aspect of the present disclosure is that in the
first or second aspect of the present disclosure, the refrigerant
circuit (50) is provided with an expansion valve (55) whose degree
of opening is variable, at a location between the first adsorption
heat exchanger (51) and the second adsorption heat exchanger (52),
and the expansion valve (55) is maintained in a fully open state
during the second operation.
[0038] In the third aspect of the present disclosure, the expansion
valve (55) is maintained in a fully open state during the second
operation. As described above, in the refrigerant circuit (50) in
the second operation, a gas refrigerant moves between the first
adsorption heat exchanger (51) and the second adsorption heat
exchanger (52). Thus, the expansion valve (55) provided between the
first adsorption heat exchanger (51) and the second adsorption heat
exchanger (52) and maintained in the fully open state can reduce
the pressure loss that is caused when the refrigerant moving
between the first adsorption heat exchanger (51) and the second
adsorption heat exchanger (52) passes through the expansion valve
(55).
[0039] The fourth aspect of the present disclosure is that in any
one of the first to third aspects of the present disclosure, a time
interval between switching operations of the switching mechanism
(40) during the second operation, for alternately switching the
flow path of the air between the first path and the second path, is
less than or equal to a time interval between switching operations
of the switching mechanism (40) during the first operation, for
alternately switching the flow path of the air between the first
path and the second path.
[0040] According to the fourth aspect of the present disclosure,
the time interval between switching operations of the switching
mechanism (40) in the second operation for alternately switching
the flow path of the air between the first path and the second path
is less than or equal to the time interval between switching
operations in the first operation. For example, in the case where
the flow path of the air is alternately switched between the first
path and the second path every three minutes in the first
operation, the flow path of the air is alternately switched between
the first path and the second path every three minutes or less than
three minutes in the second operation.
Advantages of the Invention
[0041] In the present disclosure, the humidity control apparatus
(10) performs the first operation and the second operation. As
described above, the humidity control capability of the humidity
control apparatus (10) in the second operation is lower than the
humidity control capability of the humidity control apparatus (10)
in the first operation. Thus, the humidity control apparatus (10)
of the present disclosure can supply dehumidified or humidified
outdoor air into the indoor space even under an operational
condition in which, in the conventional humidity control apparatus
(10), the only way to supply the outdoor air into the indoor space
is by stopping the compressor (53) and supplying the outdoor air
without control (that is, an operational condition in which the
humidity control load is small). Thus, the temperature and the
absolute humidity of the outdoor air to be supplied to the indoor
space in the state where the compressor (53) is stopped can be
close to the temperature and the absolute humidity of the air in
the indoor space. According to the present disclosure, a reduction
in comfort caused by supplying the outdoor air to the indoor space
without control can be prevented, and it is possible to ensure
comfort of the indoor space even in the situation in which the
compressor (53) is stopped.
[0042] In the second aspect of the present disclosure, the
controller (90) determines which operation, the first operation or
the second operation, the humidity control apparatus (10) should
perform, in consideration of the relationship between the humidity
control capability of the humidity control apparatus (10) and the
humidity control load. The controller (90) switches the operation
of the humidity control apparatus (10) from the first operation to
the second operation, in the case where the humidity control
capability is excessive even if the humidity control capability of
the humidity control apparatus (10) is set to the minimum
capability during the first operation. As described above, the
humidity control capability of the humidity control apparatus (10)
in the second operation is lower than the humidity control
capability of the humidity control apparatus (10) in the first
operation. Thus, according to the present disclosure, the
adjustable range of the humidity control capability of the humidity
control apparatus (10) can be increased, and the humidity control
apparatus (10) can have the humidity control capability suitable
for various operational conditions.
[0043] In the third aspect of the present disclosure, the
refrigerant circuit (50) is provided with an expansion valve (55),
and the expansion valve (55) is maintained in a fully open state in
the second operation. Thus, it is possible to ensure sufficient
flow rate of the refrigerant that moves between the first
adsorption heat exchanger (51) and the second adsorption heat
exchanger (52) in the second operation, and possible to increase
the humidity control capability of the humidity control apparatus
(10) in the second operation.
[0044] In the fourth aspect of the present disclosure, the time
interval between switching operations of the switching mechanism
(40) in the second operation for switching the flow path of the air
between the first path and the second path is less than or equal to
the time interval between switching operations of the switching
mechanism (40) in the first operation for switching the flow path
of the air between the first path and the second path. The amount
of moisture exchanged between the adsorption heat exchanger and air
passing through the adsorption heat exchanger abruptly increases in
a short time after supply of the air into the adsorption heat
exchanger starts, and gradually decreases thereafter. In the
present disclosure, the frequencies of the switching operations of
the switching mechanism (40) which alternately switches the flow
path of the air between the first path and the second path, are the
same between the first operation and the second operation, or
higher in the second operation than in the first operation. Thus,
according to the present disclosure, it is possible to increase the
humidity control capability of the humidity control apparatus (10)
in the second operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 shows a plan view, a right side view, and a left side
view which schematically illustrate a configuration of a humidity
control apparatus of an embodiment.
[0046] FIG. 2 shows piping system diagrams illustrating a
configuration of a refrigerant circuit. FIG. 2(A) shows an
operation during a first refrigeration cycle, and FIG. 2(B) shows
an operation during a second refrigeration cycle.
[0047] FIG. 3 shows a plan view, a right side view, and a left side
view of the humidity control apparatus which schematically
illustrate flow of air during a first batch operation of a
dehumidifying operation.
[0048] FIG. 4 shows a plan view, a right side view, and a left side
view of the humidity control apparatus which schematically
illustrate flow of air during a second batch operation of the
dehumidifying operation.
[0049] FIG. 5 shows a plan view, a right side view, and a left side
view of the humidity control apparatus which schematically
illustrate flow of air during a first batch operation of a
humidifying operation.
[0050] FIG. 6 shows a plan view, a right side view, and a left side
view of the humidity control apparatus which schematically
illustrate flow of air during a second batch operation of the
humidifying operation.
[0051] FIG. 7 shows a plan view, a right side view, and a left side
view of the humidity control apparatus which schematically
illustrate a state in which a flow path of the air is set to a
first path during a low-performance operation.
[0052] FIG. 8 shows a plan view, a right side view, and a left side
view of the humidity control apparatus which schematically
illustrate a state in which a flow path of the air is set to a
second path during the low-performance operation.
[0053] FIG. 9 shows a piping system diagram of the refrigerant
circuit, illustrating flow of the refrigerant during the
low-performance operation performed when a temperature and absolute
humidity of outdoor air are higher than those of indoor air. FIG.
9(A) shows the flow of the refrigerant when the flow path of the
air is set to the first path. FIG. 9(B) shows the flow of the
refrigerant when the flow path of the air is set to the second
path.
[0054] FIG. 10 shows a piping system diagram of the refrigerant
circuit, illustrating flow of the refrigerant during the
low-performance operation performed when a temperature and absolute
humidity of outdoor air are lower than those of indoor air. FIG.
10(A) shows the flow of the refrigerant when the flow path of the
air is set to the first path. FIG. 10(B) shows the flow of the
refrigerant when the flow path of the air is set to the second
path.
[0055] FIG. 11 is a flow chart showing control operation by a
controller.
DESCRIPTION OF EMBODIMENTS
[0056] An embodiment of the present disclosure will be described in
detail based on the drawings. The following embodiment is merely a
preferred example in nature, and is not intended to limit the
scope, applications, and use of the invention.
[0057] A humidity control apparatus (10) of the present embodiment
controls humidity of an indoor space, and also ventilates the
indoor space. The humidity control apparatus (10) controls humidity
of outdoor air (OA) taken therein to supply the outdoor air (OA) to
the indoor space, and simultaneously exhausts indoor air (RA) taken
therein to an outdoor space.
[0058] <General Configuration of Humidity Control
Apparatus>
[0059] The humidity control apparatus (10) will be described with
reference to FIG. 1. The terms "upper," "lower," "left," "right,"
"front," "rear," "near" and "far" as used herein correspond to the
directions when the humidity control apparatus (10) is viewed from
its front surface side, unless otherwise defined.
[0060] The humidity control apparatus (10) has a casing (11). A
refrigerant circuit (50) is accommodated in the casing (11). A
first adsorption heat exchanger (51), a second adsorption heat
exchanger (52), a compressor (53), a four-way valve (54), and an
electric expansion valve (55) are connected to the refrigerant
circuit (50). Details of the refrigerant circuit (50) will be
described later.
[0061] The casing (11) is formed in a rectangular parallelepiped
shape that is slightly flattened and has a relatively low height.
The casing (11) is provided with an outside-air inlet (24), a
room-air inlet (23), an air supply opening (22), and an exhaust
opening (21).
[0062] The outside-air inlet (24) and the room-air inlet (23) are
formed in a rear surface panel (13) of the casing (11). The
outside-air inlet (24) is located at a lower portion of the rear
surface panel (13). The room-air inlet (23) is located at an upper
portion of the rear surface panel (13). The air supply opening (22)
is formed in a first side surface panel (14) of the casing (11).
The air supply opening (22) is located near the end of the first
side surface panel (14) which is close to a front surface panel
(12) of the casing (11). The exhaust opening (21) is formed in a
second side surface panel (15) of the casing (11). The exhaust
opening (21) is located near the end of the second side surface
panel (15) which is close to the front surface panel (12).
[0063] In the internal space of the casing (11), an upstream-side
partition (71), a downstream-side partition (72), and a center
partition (73) are provided. Each of the partitions (71-73) is
provided upright on a bottom plate of the casing (11) to partition
the internal space of the casing (11) from the bottom plate to a
top plate of the casing (11).
[0064] The upstream-side partition (71) and the downstream-side
partition (72) are located in an orientation parallel to the front
surface panel (12) and the rear surface panel (13), and are spaced
a certain distance apart each other in a front-rear direction of
the casing (11). The upstream-side partition (71) is located closer
to the rear surface panel (13). The downstream-side partition (72)
is located closer to the front surface panel (12). The location of
the center partition (73) will be described later.
[0065] The internal space of the casing (11) between the
upstream-side partition (71) and the rear surface panel (13) is
partitioned into two spaces (i.e., upper and lower spaces). The
upper space forms a room air-side passage (32), and the lower space
forms an outside air-side passage (34). The room air-side passage
(32) communicates with the indoor space via a duct connected to the
room-air inlet (23). The outside air-side passage (34) communicates
with the outdoor space via a duct connected to the outside-air
inlet (24).
[0066] The room air-side passage (32) is provided with a room
air-side filter (27), a room air temperature sensor (91), and a
room air humidity sensor (92). The room air temperature sensor (91)
measures temperature of the indoor air flowing in the room air-side
passage (32). The room air humidity sensor (92) measures relative
humidity of the indoor air flowing in the room air-side passage
(32). On the other hand, the outside air-side passage (34) is
provided with an outside air-side filter (28), an outside air
temperature sensor (93), and an outside air humidity sensor (94).
The outside air temperature sensor (93) measures temperature of the
outdoor air flowing in the outside air-side passage (34). The
outside air humidity sensor (94) measures relative humidity of the
outdoor air flowing in the outside air-side passage (34). In FIGS.
3-8, the room air temperature sensor (91), the room air humidity
sensor (92), the outside air temperature sensor (93), and the
outside air humidity sensor (94) are not shown.
[0067] The internal space of the casing (11) between the
upstream-side partition (71) and the downstream-side partition (72)
is partitioned into left and right spaces by the center partition
(73). The space on the right side of the center partition (73)
forms a first heat exchanger chamber (37), and the space on the
left side of the center partition (73) forms a second heat
exchanger chamber (38). The first adsorption heat exchanger (51) is
accommodated in the first heat exchanger chamber (37). The second
adsorption heat exchanger (52) is accommodated in the second heat
exchanger chamber (38). Although not shown, the electric expansion
valve (55) of the refrigerant circuit (50) is accommodated in the
first heat exchanger chamber (37).
[0068] Each of the adsorption heat exchangers (51, 52) is a
so-called cross-fin type fin-and-tube heat exchanger which carries
an adsorbent on its surface. Each of the adsorption heat exchangers
(51, 52) as a whole is formed in a thick rectangular plate shape or
in a flat rectangular parallelepiped shape. The adsorption heat
exchangers (51, 52) are provided upright in the corresponding heat
exchanger chambers (37, 38) such that their front and rear surfaces
are parallel to the upstream-side partition (71) and the
downstream-side partition (72).
[0069] Part of the internal space of the casing (11) along the
front surface of the downstream-side partition (72) is partitioned
into upper and lower spaces. Of the upper and lower spaces, the
upper space forms an air-supply-side passage (31) and the lower
space forms an exhaust-side passage (33).
[0070] The upstream-side partition (71) is provided with four
dampers (41-44) that can be opened/closed. Each of the dampers
(41-44) is generally formed in a horizontally-oriented rectangular
shape. Specifically, in a portion of the upstream-side partition
(71) facing the room air-side passage (32) (an upper portion of the
upstream-side partition (71)), a first room air-side damper (41) is
attached on the right of the center partition (73), and a second
room air-side damper (42) is attached on the left of the center
partition (73). In a portion of the upstream-side partition (71)
facing the outside air-side passage (34) (a lower portion of the
upstream-side partition (71)), a first outside air-side damper (43)
is attached on the right of the center partition (73), and a second
outside air-side damper (44) is attached on the left of the center
partition (73). The four dampers (41-44) provided on the
upstream-side partition (71) form a switching mechanism (40)
configured to switch the flow path of the air.
[0071] The downstream-side partition (72) is provided with four
dampers (45-48) which can be opened/closed. Each of the dampers
(45-48) is generally formed in a horizontally-oriented rectangular
shape. Specifically, in a portion of the downstream-side partition
(72) facing the air-supply-side passage (31) (an upper portion of
the downstream-side partition (72)), a first air supply-side damper
(45) is attached on the right of the center partition (73), and a
second air supply-side damper (46) is attached on the left of the
center partition (73). Further, in a portion of the downstream-side
partition (72) facing the exhaust-side passage (33) (a lower
portion of the downstream-side partition (72)), a first
exhaust-side damper (47) is attached on the right of the center
partition (73), and a second exhaust-side damper (48) is attached
on the left of the center partition (73). The four dampers (45-48)
provided on the downstream-side partition (72) form a switching
mechanism (40) configured to switch the flow path of the air.
[0072] In the casing (11), the space between the air-supply-side
passage (31) and the exhaust-side passage (33), and the front
surface panel (12), is partitioned by a partition (77) into left
and right spaces. The space on the right of the partition (77)
forms an air supply fan chamber (36), and the space on the left of
the partition (77) forms an exhaust fan chamber (35).
[0073] An air supply fan (26) is accommodated in the air supply fan
chamber (36). An exhaust fan (25) is accommodated in the exhaust
fan chamber (35). Each of the air supply fan (26) and the exhaust
fan (25) is a centrifugal multiblade fan (a so-called sirocco fan).
The air supply fan (26) blows out the air taken from the
downstream-side partition (72) side toward the air supply opening
(22). The exhaust fan (25) blows out the air taken from the
downstream-side partition (72) side toward the exhaust opening
(21).
[0074] The compressor (53) of the refrigerant circuit (50) and the
four-way valve (54) are accommodated in the air supply fan chamber
(36). The compressor (53) and the four-way valve (54) are located
in the air supply fan chamber (36) and between the air supply fan
(26) and the partition (77).
[0075] <Configuration of Refrigerant Circuit>
[0076] As illustrated in FIG. 2, the refrigerant circuit (50) is a
closed circuit including the first adsorption heat exchanger (51),
the second adsorption heat exchanger (52), the compressor (53), the
four-way valve (54), and the electric expansion valve (55). The
refrigerant circuit (50) allows a refrigerant, filling the
refrigerant circuit (50), to circulate therethrough to perform a
vapor-compression refrigeration cycle. Although not shown, a
plurality of temperature sensors and pressure sensors are attached
to the refrigerant circuit (50).
[0077] In the refrigerant circuit (50), the compressor (53) has its
discharge side connected to a first port of the four-way valve
(54), and its suction side connected to a second port of the
four-way valve (54). In the refrigerant circuit (50), the first
adsorption heat exchanger (51), the electric expansion valve (55),
and the second adsorption heat exchanger (52) are sequentially
arranged from the third port to the fourth port of the four-way
valve (54).
[0078] The four-way valve (54) can switch between a first state
(the state shown in FIG. 2(A)) in which the first port and the
third port communicate with each other and the second port and the
fourth port communicate with each other, and a second state (the
state shown in FIG. 2(B)) in which the first port and the fourth
port communicate with each other and the second port and the third
port communicate with each other.
[0079] The compressor (53) is a hermetic compressor which
accommodates, in a single casing, a compression mechanism and an
electric motor configured to drive the compression mechanism.
Alternating current is supplied to the electric motor of the
compressor (53) via an inverter. When an output frequency of the
inverter (i.e., an operation frequency of the compressor) is
changed, the rotating speed of the electric motor and the
compression mechanism driven by the electric motor is changed. As a
result, the operation capacity of the compressor (53) changes.
[0080] <Configuration of Controller>
[0081] The humidity control apparatus (10) is provided with a
controller (90) (see FIG. 2). Measurement values of the room air
humidity sensor (92), the room air temperature sensor (91), the
outside air humidity sensor (94), and the outside air temperature
sensor (93) are input in the controller (90). Further, measurement
values of the temperature sensors and the pressure sensors provided
at the refrigerant circuit (50) are input in the controller (90).
The controller (90) controls operation of the humidity control
apparatus (10) based on the input measurement values.
[0082] The controller (90) switches the operation of the humidity
control apparatus (10) among a dehumidifying operation, a
low-performance operation, and a simple ventilation operation,
which will be described later. The controller (90) controls
operations of the dampers (41-48), the fans (25, 26), the
compressor (53), the electric expansion valve (55), and the
four-way valve (54) during the above operations.
[0083] --Operation--
[0084] The humidity control apparatus (10) of the present
embodiment selectively performs the dehumidifying operation, the
humidifying operation, the low-performance operation, and the
simple ventilation operation. The dehumidifying operation and the
humidifying operation are a first operation in which the compressor
(53) is actuated and the switching mechanism (40) switches the flow
path of the air. The low-performance operation is a second
operation in which the compressor (53) is stopped and the switching
mechanism (40) switches the flow path of the air. The simple
ventilation operation is an operation in which the compressor (53)
and the switching mechanism (40) are both stopped.
[0085] The air supply fan (26) and the exhaust fan (25) are
activated in each of the dehumidifying operation, the humidifying
operation, the low-performance operation, and the simple
ventilation operation. The humidity control apparatus (10) supplies
the outdoor air (OA) taken therein into the indoor space as supply
air (SA), and exhausts the indoor air (RA) taken therein to the
outdoor space as exhaust air (EA).
[0086] <Dehumidifying Operation>
[0087] In the dehumidifying operation, the humidity control
apparatus (10) takes the outdoor air as first air into the casing
(11) from the outside-air inlet (24), and takes the indoor air as
second air into the casing (11) through the room-air inlet (23).
Further, in the refrigerant circuit (50), the compressor (53) is
actuated and a degree of opening of the electric expansion valve
(55) is adjusted. The humidity control apparatus (10) in the
dehumidifying operation performs a first batch operation and a
second batch operation, which will be described below, alternately
every three minutes.
[0088] The first batch operation of the dehumidifying operation
will be described first.
[0089] As illustrated in FIG. 3, the switching mechanism (40) sets
the flow path of the air to the second path in the first batch
operation of the dehumidifying operation. Specifically, the first
room air-side damper (41), the second outside air-side damper (44),
the second air supply-side damper (46), and the first exhaust-side
damper (47) are in an open state, and the second room air-side
damper (42), the first outside air-side damper (43), the first air
supply-side damper (45), and the second exhaust-side damper (48)
are in a closed state. Further, in the first batch operation, the
refrigerant circuit (50) performs the first refrigeration cycle
operation. That is, in the refrigerant circuit (50), the four-way
valve (54) is set to the first state (the state shown in FIG.
2(A)), wherein the first adsorption heat exchanger (51) serves as a
condenser and the second adsorption heat exchanger (52) serves as
an evaporator.
[0090] The first air having flowed into the outside air-side
passage (34) and passed through the outside air-side filter (28),
flows into the second heat exchanger chamber (38) through the
second outside air-side damper (44) and thereafter passes through
the second adsorption heat exchanger (52). In the second adsorption
heat exchanger (52), moisture in the first air is adsorbed to the
adsorbent, and adsorption heat generated at this time is absorbed
by the refrigerant. The first air dehumidified by the second
adsorption heat exchanger (52) passes through the second air
supply-side damper (46) and flows into the air-supply-side passage
(31). After passing through the air supply fan chamber (36), the
first air is supplied to the indoor space through the air supply
opening (22).
[0091] On the other hand, the second air having flowed into the
room air-side passage (32) and passed through the room air-side
filter (27), flows into the first heat exchanger chamber (37)
through the first room air-side damper (41) and passes through the
first adsorption heat exchanger (51) thereafter. In the first
adsorption heat exchanger (51), moisture is desorbed from the
adsorbent heated by the refrigerant, and the desorbed moisture is
given to the second air. The second air to which the moisture has
been given in the first adsorption heat exchanger (51) flows into
the exhaust-side passage (33) through the first exhaust-side damper
(47). After passing through the exhaust fan chamber (35), the
second air is exhausted to the outdoor space through the exhaust
opening (21).
[0092] Now, the second batch operation of the dehumidifying
operation will be described.
[0093] As illustrated in FIG. 4, the switching mechanism (40) sets
the flow path of the air to the first path in the second batch
operation of the dehumidifying operation. Specifically, the second
room air-side damper (42), the first outside air-side damper (43),
the first air supply-side damper (45), and the second exhaust-side
damper (48) are in an open state, and the first room air-side
damper (41), the second outside air-side damper (44), the second
air supply-side damper (46), and the first exhaust-side damper (47)
are in a closed state. Further, in the second batch operation, the
refrigerant circuit (50) performs the second refrigeration cycle
operation. That is, in the refrigerant circuit (50), the four-way
valve (54) is set to the second state (the state shown in FIG.
2(B)), wherein the first adsorption heat exchanger (51) serves as
an evaporator and the second adsorption heat exchanger (52) serves
as a condenser.
[0094] The first air having flowed into the outside air-side
passage (34) and passed through the outside air-side filter (28),
flows into first heat exchanger chamber (37) through the first
outside air-side damper (43) and thereafter passes through the
first adsorption heat exchanger (51). In the first adsorption heat
exchanger (51), moisture in the first air is adsorbed to the
adsorbent, and adsorption heat generated at this time is absorbed
by the refrigerant. The first air dehumidified by the first
adsorption heat exchanger (51) passes through the first air
supply-side damper (45) and flows into the air-supply-side passage
(31). After passing through the air supply fan chamber (36), the
first air is supplied to the indoor space through the air supply
opening (22).
[0095] On the other hand, the second air having flowed into the
room air-side passage (32) and passed through the room air-side
filter (27), flows into the second heat exchanger chamber (38)
through the second room air-side damper (42) and passes through the
second adsorption heat exchanger (52) thereafter. In the second
adsorption heat exchanger (52), moisture is desorbed from the
adsorbent heated by the refrigerant, and the desorbed moisture is
given to the second air. The second air to which the moisture has
been given in the second adsorption heat exchanger (52) flows into
the exhaust-side passage (33) through the second exhaust-side
damper (48). After passing through the exhaust fan chamber (35),
the second air is exhausted to the outdoor space through the
exhaust opening (21).
[0096] <Humidifying Operation>
[0097] In the humidifying operation, the humidity control apparatus
(10) takes the outdoor air as second air into the casing (11) from
the outside-air inlet (24), and takes the indoor air as first air
in the casing (11) from the room-air inlet (23). Further, in the
refrigerant circuit (50), the compressor (53) is actuated and a
degree of opening of the electric expansion valve (55) is adjusted.
The humidity control apparatus (10) in the humidifying operation
performs a first batch operation and a second batch operation,
which will be described below, alternately every four minutes.
[0098] The first batch operation of the humidifying operation will
be described first.
[0099] As illustrated in FIG. 5, the switching mechanism (40) sets
the flow path of the air to the first path in the first batch
operation of the humidifying operation. Specifically, the second
room air-side damper (42), the first outside air-side damper (43),
the first air supply-side damper (45), and the second exhaust-side
damper (48) are in an open state, and the first room air-side
damper (41), the second outside air-side damper (44), the second
air supply-side damper (46), and the first exhaust-side damper (47)
are in a closed state. Further, in the first batch operation, the
refrigerant circuit (50) performs the first refrigeration cycle
operation. That is, in the refrigerant circuit (50), the four-way
valve (54) is set to the first state (the state shown in FIG.
2(A)), wherein the first adsorption heat exchanger (51) serves as a
condenser and the second adsorption heat exchanger (52) serves as
an evaporator.
[0100] The first air having flowed into the room air-side passage
(32) and passed through the room air-side filter (27), flows into
the second heat exchanger chamber (38) through the second room
air-side damper (42) and thereafter passes through the second
adsorption heat exchanger (52). In the second adsorption heat
exchanger (52), moisture in the first air is adsorbed to the
adsorbent, and adsorption heat generated at this time is absorbed
by the refrigerant. The first air of which the moisture is taken in
the second adsorption heat exchanger (52) flows into the
exhaust-side passage (33) through the second exhaust-side damper
(48). After passing through the exhaust fan chamber (35), the first
air is exhausted to the outdoor space through the exhaust opening
(21).
[0101] On the other hand, the second air having flowed into the
outside air-side passage (34) and passed through the outside
air-side filter (28), flows into the first heat exchanger chamber
(37) through the first outside air-side damper (43) and passes
through the first adsorption heat exchanger (51) thereafter. In the
first adsorption heat exchanger (51), moisture is desorbed from the
adsorbent heated by the refrigerant, and the desorbed moisture is
given to the second air. The second air humidified by the first
adsorption heat exchanger (51) flows into the air-supply-side
passage (31) through the first air supply-side damper (45). After
passing through the air supply fan chamber (36), the second air is
supplied to the indoor space through the air supply opening
(22).
[0102] Now, the second batch operation of the humidifying operation
will be described.
[0103] As illustrated in FIG. 6, the switching mechanism (40) sets
the flow path of the air to the second path in the second batch
operation of the humidifying operation. Specifically, the first
room air-side damper (41), the second outside air-side damper (44),
the second air supply-side damper (46), and the first exhaust-side
damper (47) are in an open state, and the second room air-side
damper (42), the first outside air-side damper (43), the first air
supply-side damper (45), and the second exhaust-side damper (48)
are in a closed state. Further, in the second batch operation, the
refrigerant circuit (50) performs the second refrigeration cycle
operation. That is, in the refrigerant circuit (50), the four-way
valve (54) is set to the second state (the state shown in FIG.
2(B)), wherein the first adsorption heat exchanger (51) serves as
an evaporator and the second adsorption heat exchanger (52) serves
as a condenser.
[0104] The first air having flowed into the room air-side passage
(32) and passed through the room air-side filter (27), flows into
the first heat exchanger chamber (37) through the first room
air-side damper (41) and thereafter passes through the first
adsorption heat exchanger (51). In the first adsorption heat
exchanger (51), moisture in the first air is adsorbed to the
adsorbent, and the adsorption heat generated at this time is
absorbed by the refrigerant. The first air of which the moisture is
taken in the first adsorption heat exchanger (51) flows into the
exhaust-side passage (33) through the first exhaust-side damper
(47). After passing through the exhaust fan chamber (35), the first
air is exhausted to the outdoor space through the exhaust opening
(21).
[0105] On the other hand, the second air having flowed into the
outside air-side passage (34) and passes through the outside
air-side filter (28), flows into the second heat exchanger chamber
(38) through the second outside air-side damper (44) and passes
through the second adsorption heat exchanger (52) thereafter. In
the second adsorption heat exchanger (52), moisture is desorbed
from the adsorbent heated by the refrigerant, and the desorbed
moisture is given to the second air. The second air humidified by
the second adsorption heat exchanger (52) flows into the
air-supply-side passage (31) through the second air supply-side
damper (46). After passing through the air supply fan chamber (36),
the second air is supplied to the indoor space through the air
supply opening (22).
[0106] <Low-Performance Operation>
[0107] In the humidity control apparatus (10) in the
low-performance operation, the compressor (53) of the refrigerant
circuit (50) is stopped and the electric expansion valve (55) is
maintained in a fully open state. Further, in the humidity control
apparatus (10) in the low-performance operation, the switching
mechanism (40) switches the flow path of the air.
[0108] The switching mechanism (40) switches the flow path of the
air between the first path and the second path alternately every
three minutes. That is, the time interval between the switching
operations of the switching mechanism (40) for switching the flow
path of the air in the low-performance operation is the same as the
time interval between the switching operations of the switching
mechanism (40) for switching the flow path of the air in the
dehumidifying operation. Since the compressor (53) is stopped, the
four-way valve (54) may be in the first state or may be in the
second state.
[0109] As illustrated in FIG. 7, in the state where the switching
mechanism (40) sets the flow path of the air to the first path, the
second room air-side damper (42), the first outside air-side damper
(43), the first air supply-side damper (45), and the second
exhaust-side damper (48) are in the open state, and the first room
air-side damper (41), the second outside air-side damper (44), the
second air supply-side damper (46), and the first exhaust-side
damper (47) are in the closed state. The outdoor air passes through
the first adsorption heat exchanger (51) and is thereafter supplied
to the indoor space. The indoor air passes through the second
adsorption heat exchanger (52) and is thereafter exhausted to the
outdoor space.
[0110] On the other hand, as illustrated in FIG. 8, in the state
where the switching mechanism (40) sets the flow path of the air to
the second path, the first room air-side damper (41), the second
outside air-side damper (44), the second air supply-side damper
(46), and the first exhaust-side damper (47) are in the open state,
and the second room air-side damper (42), the first outside
air-side damper (43), the first air supply-side damper (45), and
the second exhaust-side damper (48) are in the closed state. The
outdoor air passes through the second adsorption heat exchanger
(52) and is thereafter supplied to the indoor space. The indoor air
passes through the first adsorption heat exchanger (51) and is
thereafter exhausted to the outdoor space.
[0111] First, of the low-performance operation of the humidity
control apparatus (10), an example in which the temperature and the
absolute humidity of the outdoor air are slightly higher than those
of the indoor air (e.g., a case in which the room is cooled in late
spring or early autumn) will be described. In this case, the
humidity control apparatus (10) in the low-performance operation
cools and dehumidifies the outdoor air to be supplied to the indoor
space. The mechanism will be described below with reference to FIG.
9.
[0112] A state in which the flow path of the air is set to the
first path will be described first. In this state, as illustrated
in FIG. 9(A), the outdoor air passes through the first adsorption
heat exchanger (51), and the indoor air passes through the second
adsorption heat exchanger (52).
[0113] Even during a period when the compressor (53) is stopped,
the liquid refrigerant remains in the first adsorption heat
exchanger (51). When the outdoor air passes through the first
adsorption heat exchanger (51), the liquid refrigerant in the first
adsorption heat exchanger (51) absorbs the adsorption heat, which
is generated when the moisture in the outdoor air is adsorbed to
the adsorbent, and further absorbs heat from the outdoor air and
evaporates.
[0114] On the other hand, the indoor air whose temperature is lower
than the outdoor air flows in the second adsorption heat exchanger
(52). Thus, the refrigerant evaporated in the first adsorption heat
exchanger (51) passes through the electric expansion valve (55),
and thereafter flows into the second adsorption heat exchanger (52)
and is condensed. In the second adsorption heat exchanger (52), the
adsorbent is heated by heat of condensation dissipated from the
refrigerant, and moisture is desorbed from the adsorbent and is
given to the indoor air. In the second adsorption heat exchanger
(52), the heat transferred by the refrigerant from the first
adsorption heat exchanger (51) is dissipated into the indoor
air.
[0115] After that, in the humidity control apparatus (10) in the
low-performance operation, the flow path of the air is switched
from the first path to the second path. That is, as illustrated in
FIG. 9(B), the air passing through the first adsorption heat
exchanger (51) is changed from the outdoor air to the indoor air,
and the air passing through the second adsorption heat exchanger
(52) is changed from the indoor air to the outdoor air.
[0116] As described above, in the state where the flow path of the
air is set to the first path (the state of FIG. 9(A)), moisture is
desorbed from the adsorbent in the second adsorption heat exchanger
(52). Thus, after the flow path of the air is switched to the
second path, the moisture contained in the outdoor air is adsorbed
to the second adsorption heat exchanger (52). The refrigerant in
the second adsorption heat exchanger (52) absorbs adsorption heat,
which is generated when the moisture in the outdoor air is adsorbed
to the adsorbent, and further absorbs heat from the outdoor air and
evaporates. Thus, the temperature and the absolute humidity of the
outdoor air passing through the second adsorption heat exchanger
(52) are reduced. As a result, the temperature and the absolute
humidity of the outdoor air become close to the temperature and the
absolute humidity of air in the indoor space.
[0117] On the other hand, the indoor air whose temperature is lower
than the temperature of the outdoor air flows in the first
adsorption heat exchanger (51). Thus, the refrigerant which has
evaporated in the second adsorption heat exchanger (52) passes
through the electric expansion valve (55) and thereafter flows into
the first adsorption heat exchanger (51) and is condensed. In the
first adsorption heat exchanger (51), the adsorbent is heated by
heat of condensation dissipated from the refrigerant, and moisture
is desorbed from the adsorbent. That is, in the first adsorption
heat exchanger (51), moisture in the outdoor air is adsorbed when
the flow path of the air is set to the first path, and the moisture
is released into the indoor air when the flow path of the air is
set to the second path. Further, in the first adsorption heat
exchanger (51), the heat transferred by the refrigerant from the
second adsorption heat exchanger (52) is dissipated into the indoor
air.
[0118] After that, in the humidity control apparatus (10) in the
low-performance operation, the flow path of the air is switched
from the second path to the first path again. That is, as
illustrated in FIG. 9(A), the air passing through the first
adsorption heat exchanger (51) is changed from the indoor air to
the outdoor air, and the air passing through the second adsorption
heat exchanger (52) is changed from the outdoor air to the indoor
air.
[0119] As described above, in the state shown in FIG. 9(A), the
outdoor air is cooled and dehumidified in the first adsorption heat
exchanger (51). That is, the first adsorption heat exchanger (51)
which releases moisture into the indoor air in the state shown in
FIG. 9(B), adsorbs moisture in the outdoor air. Further, the
refrigerant in the first adsorption heat exchanger (51) absorbs
heat from the outdoor air. As a result, the temperature and the
absolute humidity of the outdoor air become close to the
temperature and the absolute humidity of the indoor space.
[0120] Further, as described above, moisture and heat are released
from the second adsorption heat exchanger (52) into the indoor air
in the state shown in FIG. 9(A). That is, the second adsorption
heat exchanger (52) releases heat transferred by the refrigerant
from the first adsorption heat exchanger (51), and moisture
adsorbed when the flow path of the air is set to the second path,
into the indoor air.
[0121] Next, of the low-performance operation of the humidity
control apparatus (10), an example in which the temperature and the
absolute humidity of the outdoor air are slightly lower than those
of the indoor air (e.g., a case in which the room is heated in
early spring or late autumn) will be described. In this case, the
humidity control apparatus (10) in the low-performance operation
heats and humidifies the outdoor air to be supplied into the indoor
space. The mechanism will be described below with reference to FIG.
10.
[0122] A state in which the flow path of the air is set to the
first path will be described first. As illustrated in FIG. 10(A),
in this state, the outdoor air passes through the first adsorption
heat exchanger (51), and the indoor air passes through the second
adsorption heat exchanger (52).
[0123] Even during a period when the compressor (53) is stopped,
the liquid refrigerant remains in the second adsorption heat
exchanger (52). When the indoor air passes through the second
adsorption heat exchanger (52), the liquid refrigerant in the
second adsorption heat exchanger (52) absorbs the adsorption heat,
which is generated when the moisture in the indoor air is adsorbed
to the adsorbent, and further absorbs heat from the indoor air and
evaporates.
[0124] On the other hand, the outdoor air whose temperature is
lower than the temperature of the indoor air flows in the first
adsorption heat exchanger (51). Thus, the refrigerant evaporated in
the second adsorption heat exchanger (52) flows into the first
adsorption heat exchanger (51) and is condensed. In the first
adsorption heat exchanger (51), the adsorbent is heated by heat of
condensation dissipated from the refrigerant, and moisture is
desorbed from the adsorbent and is given to the outdoor air. In the
first adsorption heat exchanger (51), the heat transferred by the
refrigerant from the second adsorption heat exchanger (52) is
dissipated into the outdoor air.
[0125] After that, in the humidity control apparatus (10) in the
low-performance operation, the flow path of the air is switched
from the first path to the second path. That is, as illustrated in
FIG. 10(B), the air passing through the first adsorption heat
exchanger (51) is changed from the outdoor air to the indoor air,
and the air passing through the second adsorption heat exchanger
(52) is changed from the indoor air to the outdoor air.
[0126] As described above, in the state where the flow path of the
air is set to the first path (the state of FIG. 10(A)), moisture is
desorbed from the adsorbent in the first adsorption heat exchanger
(51). Thus, after the flow path of the air is switched to the
second path, the moisture contained in the indoor air is adsorbed
to the first adsorption heat exchanger (51). The refrigerant in the
first adsorption heat exchanger (51) absorbs adsorption heat, which
is generated when the moisture in the indoor air is adsorbed to the
adsorbent, and further absorbs heat from the indoor air and
evaporates.
[0127] On the other hand, the outdoor air whose temperature is
lower than the temperature of the indoor air flows in the second
adsorption heat exchanger (52). Thus, the refrigerant which has
evaporated in the first adsorption heat exchanger (51) passes
through the electric expansion valve (55) and thereafter flows into
the second adsorption heat exchanger (52) and is condensed. In the
second adsorption heat exchanger (52), the adsorbent is heated by
heat of condensation dissipated from the refrigerant, and moisture
is desorbed from the adsorbent. That is, in the second adsorption
heat exchanger (52), moisture in the indoor air is adsorbed when
the flow path of the air is set to the first path, and the moisture
is released into the outdoor air when the flow path of the air is
set to the second path. Further, in the second adsorption heat
exchanger (52), the heat transferred by the refrigerant from the
first adsorption heat exchanger (51) is dissipated into the outdoor
air. Thus, the temperature and the absolute humidity of the outdoor
air passing through the second adsorption heat exchanger (52) are
increased. As a result, the temperature and the absolute humidity
of the outdoor air become close to the temperature and the absolute
humidity of air in the indoor space.
[0128] After that, in the humidity control apparatus (10) in the
low-performance operation, the flow path of the air is switched
from the second path to the first path again. That is, as
illustrated in FIG. 10(A), the air passing through the first
adsorption heat exchanger (51) is changed from the indoor air to
the outdoor air, and the air passing through the second adsorption
heat exchanger (52) is changed from the outdoor air to the indoor
air.
[0129] As described above, in the state shown in FIG. 10(A), the
adsorbent adsorbs the moisture in the indoor air, and the
refrigerant absorbs heat from the indoor air, in the second
adsorption heat exchanger (52). That is, the second adsorption heat
exchanger (52) takes moisture and heat from the indoor air.
[0130] Further, as described above, in the state shown in FIG.
10(A), the outdoor air is heated and humidified in the first
adsorption heat exchanger (51). That is, the first adsorption heat
exchanger (51) gives the moisture taken from the indoor air in the
state shown in FIG. 10(B), to the outdoor air. Further, in the
first adsorption heat exchanger (51), the heat transferred by the
refrigerant from the second adsorption heat exchanger (52) is given
to the outdoor air. As a result, the temperature and the absolute
humidity of the outdoor air become close to the temperature and the
absolute humidity of the indoor space.
[0131] As described above, even during the low-performance
operation where the compressor (53) is stopped, the humidity
control apparatus (10) controls the temperature and the absolute
humidity of the outdoor air to be supplied to the indoor space.
However, a flow rate of the refrigerant which moves between the
first adsorption heat exchanger (51) and the second adsorption heat
exchanger (52) in the refrigerant circuit (50) in the
low-performance operation is lower than a flow rate of the
refrigerant which circulates in the refrigerant circuit (50) in the
dehumidifying operation and the humidifying operation in which the
compressor (53) is actuated. Thus, the dehumidification properties
of the humidity control apparatus (10) in the low-performance
operation are lower than the dehumidification properties of the
humidity control apparatus (10) in the dehumidifying operation.
Further, the humidification properties of the humidity control
apparatus (10) in the low-performance operation are lower than the
humidification properties of the humidity control apparatus (10) in
the humidifying operation.
[0132] <Simple Ventilation Operation>
[0133] In the humidity control apparatus (10) in the simple
ventilation operation, the compressor (53) of the refrigerant
circuit (50) is stopped, and the electric expansion valve (55) is
in a fully closed state, in general.
[0134] Further, in the humidity control apparatus (10) in the
low-performance operation, the switching mechanism (40) is stopped,
and the flow path of the air is fixed to either one of the first
path or the second path. In the case where the flow path of the air
is set to the first path, the outdoor air and the indoor air flow
in the humidity control apparatus (10) as illustrated in FIG. 7.
That is, the outdoor air is supplied to the indoor space after
passing through the first adsorption heat exchanger (51), and the
indoor air is exhausted to the outdoor space after passing through
the second adsorption heat exchanger (52). On the other hand, in
the case where the flow path of the air is set to the second path,
the outdoor air and the indoor air flow in the humidity control
apparatus (10) as illustrated in FIG. 8. That is, the outdoor air
is supplied to the indoor space after passing through the second
adsorption heat exchanger (52), and the indoor air is exhausted to
the outdoor space after passing through the first adsorption heat
exchanger (51).
[0135] In the low-performance operation, the switching mechanism
(40) switches the flow path of the air every predetermined period
or time, whereas in the simple ventilation operation, the switching
mechanism (40) is stopped and the flow path of the air is fixed.
Thus, in the simple ventilation operation, the adsorption heat
exchangers (51, 52) do not exchange moisture or heat with the air
passing through the adsorption heat exchangers (51, 52). As a
result, the outdoor air is supplied to the indoor space without
control of the temperature and the humidity. Further, the indoor
air is exhausted to the outdoor space without control of the
temperature and humidity.
[0136] --Control Operation of Controller--
[0137] Control operation of the controller (90) will be described.
Here, the operation in which the controller (90) selects an
operation mode of the humidity control apparatus (10) will be
described with reference to the flow chart of FIG. 11. The
controller (90) repeats the control operation of FIG. 11 every
predetermined period of time (e.g., every two minutes).
[0138] In step ST1, the controller (90) calculates a target value
of the absolute humidity of air (target absolute humidity: X_tg) to
be supplied to the indoor space from the air supply opening (23).
In the calculation, the controller (90) determines the target
absolute humidity X_tg such that an absolute humidity X_ra of the
indoor air will be a set value (X_set) of the absolute humidity,
using a set value (X_set) of the absolute humidity of air in the
indoor space, an absolute humidity X_oa of the outdoor air, and the
absolute humidity X_ra of the indoor air. Further, the controller
(90) calculates the absolute humidity X_oa of the outdoor air,
using measurement values of the outside air temperature sensor (93)
and the outside air humidity sensor (94), and calculates the
absolute humidity X_ra of the indoor air, using measurement values
of the room air temperature sensor (91) and the room air humidity
sensor (92).
[0139] In the next step ST2, the controller (90) calculates a
necessary operation frequency F_n of the compressor (53). In the
calculation, the controller (90) calculates an operation frequency
of the compressor (53) such that the absolute humidity of air to be
supplied to the indoor space from the air supply opening (23) will
be the target absolute humidity X_tg, using the target absolute
humidity X_tg calculated in step ST1, the absolute humidity X_oa of
the outdoor air, and the absolute humidity X_ra of the indoor air.
The obtained operation frequency is the necessary operation
frequency F_n.
[0140] The higher the operation frequency of the compressor (53),
the larger the operation capacity of the compressor (53). The lower
the operation frequency of the compressor (53), the smaller the
operation capacity of the compressor (53). When the compressor (53)
has large operation capacity, the mass flow rate of the refrigerant
circulating in the refrigerant circuit (50) is increased, and a
heat absorption rate and a heat dissipation rate of the refrigerant
in the adsorption heat exchangers (51, 52) per unit time are
increased. As a result, the amount of moisture adsorbed to the
adsorption heat exchanger (51, 52) serving as an evaporator is
increased, and the amount of moisture desorbed from the adsorption
heat exchanger (51, 52) serving as a radiator is increased. That
is, the humidity control capability of the humidity control
apparatus (10) is increased. On the other hand, when the compressor
(53) has small operation capacity, the mass flow rate of the
refrigerant circulating in the refrigerant circuit (50) is reduced,
and the heat absorption rate and the heat dissipation rate of the
refrigerant in the adsorption heat exchangers (51, 52) are reduced.
As a result, the amount of moisture adsorbed to the adsorption heat
exchanger (51, 52) serving as an evaporator is reduced, and the
amount of moisture desorbed from the adsorption heat exchanger (51,
52) serving as a radiator is reduced. That is, the humidity control
capability of the humidity control apparatus (10) is reduced. Thus,
the controller (90) controls the operation frequency of the
compressor (53) so that the absolute humidity of air to be supplied
to the indoor space from the humidity control apparatus (10) will
be the target absolute humidity X_tg.
[0141] In the next step ST3, the controller (90) calculates a
minimum operation frequency F_min of the compressor (53). In the
calculation, the controller (90) calculates a lower limit of the
operation frequency of the compressor (53), using a temperature
T_oa and the absolute humidity X_oa of the outdoor air, and a
temperature T_ra and the absolute humidity X_ra of the indoor air.
The obtained lower limit is the minimum operation frequency F_min.
To ensure reliability of the compressor (53), operational
conditions of the compressor (53), such as a difference between a
suction pressure and a discharge pressure, need to fall within a
predetermined range. Thus, the controller (90) determines the
minimum operation frequency F_min of the compressor (53) so that
the operational conditions of the compressor (53) can fall within
the predetermined range.
[0142] In the next step ST4, the controller (90) determines whether
the absolute humidity X_oa of the outdoor air is a value in a set
humidity range or not (that is, whether a condition of
X_set1<X_ox<X_set2 holds true or not). X_set1 is a lower
limit of a set range of the absolute humidity of air in the indoor
space, and X_set2 is an upper limit of the set range of the
absolute humidity of air in the indoor space.
[0143] In the case where the condition of step ST4 holds true, the
absolute humidity of the indoor air is maintained within the set
range even if the outdoor air is supplied to the indoor space
without control. Thus, the controller (90) performs operation in
step ST5 in the case where the above condition holds true. In other
words, in such a case, the controller (90) sets the operation of
the humidity control apparatus (10) to the simple ventilation
operation.
[0144] On the other hand, in the case where the condition of step
ST4 does not hold true, the absolute humidity of air in the indoor
space may deviate from the set range if the outdoor air is supplied
to the indoor space without control. Thus, in the case where the
above condition does not hold true, the controller (90) performs
operation of step ST6.
[0145] In step ST6, the controller (90) compares the necessary
operation frequency F_n of the compressor (53) obtained in step ST2
and the minimum operation frequency F_min of the compressor (53)
obtained in step ST3. Specifically, the controller (90) determines
whether a condition of F_n.gtoreq.F_min.times.A holds true or not.
The letter "A" is a constant less than 1.0, and is set to 0.5, for
example.
[0146] In the case where the condition of step ST6 holds true, the
controller (90) performs operation of step ST7. When the above
condition holds true, the absolute humidity X_oa of the outdoor air
deviates from the set humidity range, and the necessary operation
frequency F_n of the compressor (53) is relatively high. Therefore,
it can be considered that the humidity control capability (i.e., a
humidity control load) required of the humidity control apparatus
(10) is relatively high. Thus, in step ST7, the controller (90)
sets the operation of the humidity control apparatus (10) to either
one of the dehumidifying operation or the humidifying operation.
The controller (90) selects either the dehumidifying operation or
the humidifying operation, based on setting information input in a
remote, etc., by a user or on the absolute humidity of indoor and
outdoor air.
[0147] In the case where the condition of step ST6 holds true
during the low-performance operation, it can be assumed that the
humidity control capability of the humidity control apparatus (10)
is lower than the humidity control load. Thus, in the case where
the condition of the step ST6 holds true during the low-performance
operation, the controller (90) actuates the compressor (53) and
changes the operation of the humidity control apparatus (10) from
the low-performance operation to the dehumidifying operation or the
humidifying operation.
[0148] In the humidity control apparatus (10) in the dehumidifying
operation and the humidifying operation, the controller (90)
controls an operation frequency F of the compressor (53) as
follows. That is, in the case where the necessary operation
frequency F_n of the compressor (53) is more than or equal to the
minimum operation frequency F_min (F_min <F_n), the controller
(90) sets the operation frequency F of the compressor (53) to the
necessary operation frequency F_n (F=F_n). On the other hand, in
the case where the necessary operation frequency F_n of the
compressor (53) is less than the minimum operation frequency F_min
and higher than the F_min.times.A (F_min.times.A<F_n<F_min),
the controller (90) sets the operation frequency F of the
compressor (53) to the minimum operation frequency F_min
(F=F_min).
[0149] In the case where the condition of step ST6 does not hold
true, the controller (90) performs operation of step ST8. When the
above condition does not hold true, the absolute humidity X_oa of
the outdoor air deviates from the set humidity range, and the
necessary operation frequency F_n of the compressor (53) is
relatively low. Therefore, it can be assumed that the humidity
control capability of the humidity control apparatus (10) is high
relative to the humidity control load. Thus, in step ST8, the
controller (90) sets the operation of the humidity control
apparatus (10) to the low-performance operation.
[0150] As described above, in the case where the relationship of
F_min.times.A<F_n<F_min holds true in the dehumidifying
operation and the humidifying operation, the controller (90) sets
the operation frequency F of the compressor (53) to the minimum
operation frequency F_min (F=F_min). If the condition of step ST6
does not hold true under the condition of F=F_min, it can be
assumed that the humidity control capability of the humidity
control apparatus (10) is high relative to the humidity control
load even if the operation capacity of the compressor (53) is set
to a minimum capacity. Thus, in this case, the controller (90)
stops the compressor (53), and changes the operation of the
humidity control apparatus (10) from the dehumidifying operation or
the humidifying operation to the low-performance operation.
[0151] --Advantages of Embodiment--
[0152] The humidity control apparatus (10) of the present
embodiment performs the dehumidifying operation and the humidifying
operation in which both of the compressor (53) and the switching
mechanism (40) are actuated, and the low-performance operation in
which the compressor (53) is stopped and the switching mechanism
(40) is actuated. As described above, the humidity control
capability of the humidity control apparatus (10) in the
low-performance operation is lower than the humidity control
capability of the humidity control apparatus (10) in the
dehumidifying operation and the humidifying operation.
[0153] In the conventional humidity control apparatus (10) which
does not perform the low-performance operation, the dehumidifying
operation and the humidifying operation are stopped and the simple
ventilation operation is performed when the humidity control
capability in the dehumidifying operation and the humidifying
operation is high relative to the humidity control load. However,
even when the humidity control capability of the humidity control
apparatus (10) is high relative to the humidity control load, there
is a certain degree of difference in the temperature and the
absolute humidity between the outdoor space air and the indoor
space air, in general. Thus, if the dehumidifying operation and the
humidifying operation are immediately stopped to perform the simple
ventilation operation when the humidity control capability of the
humidity control apparatus (10) is high relative to the humidity
control load, the outdoor air may be supplied to the indoor space
without control of the temperature and the absolute humidity, and
that may cause people in the room discomfort.
[0154] In contrast, the humidity control apparatus (10) of the
present embodiment can perform the low-performance operation. When
the humidity control capability of the humidity control apparatus
(10) is high relative to the humidity control load, the humidity
control apparatus (10) stops the dehumidifying operation and the
humidifying operation and performs the operation in the
low-performance operation. The outdoor air is supplied to the
indoor space without control in the simple ventilation operation,
whereas in the low-performance operation, the outdoor air is
supplied to the indoor space after the temperature and the absolute
humidity of the outdoor air are controlled.
[0155] Thus, according to the humidity control apparatus (10) of
the present embodiment, the temperature and the absolute humidity
of the outdoor air to be supplied to the indoor space can be close
to the temperature and the absolute humidity of the indoor space,
even in such an operational condition in which the humidity control
capability of the humidity control apparatus (10) is high relative
to the humidity control load and therefore in which it is necessary
to stop the dehumidifying operation and the humidifying operation.
Thus, according to the present embodiment, a reduction in comfort
caused by supplying the outdoor air to the indoor space without
control can be prevented, and it is possible to ensure comfort of
the indoor space even in the operational condition in which the
dehumidifying operation and the humidifying operation need to be
stopped.
[0156] Further, in the case where the difference between the
humidity control load and the lower limit of the adjustable range
of the humidity control capability of the humidity control
apparatus (10) is small, the stop and restart of the compressor
(53) may be frequently repeated. That is, when the compressor (53)
is stopped and the humidity control capability of the humidity
control apparatus (10) becomes zero, the outdoor air is supplied to
the indoor space without control, and therefore the humidity of the
indoor air is changed, and as a result, the compressor (53) is
restarted. When the compressor (53) restarts, the humidity of the
indoor air reaches a target value in a relatively short time, and
thus, the compressor (53) is stopped again. The frequent repetition
of stop and restart of the compressor (53) increases the likelihood
of damage of the compressor (53).
[0157] In contrast, in the humidity control apparatus (10) of the
present embodiment, the outdoor air to be supplied to the indoor
space is continuously dehumidified and humidified by the
low-performance operation, even in such an operational condition in
which the humidity control capability of the humidity control
apparatus (10) is high relative to the humidity control load and
therefore in which it is necessary to stop the dehumidifying
operation and the humidifying operation. Thus, even after the stop
of the compressor (53), it is possible to prevent an abrupt change
in the humidity of the indoor air, and extend the time until the
restart of the compressor (53) is necessary. According to the
present embodiment, the frequent repetition of the stop and restart
of the compressor (53) can be prevented. Therefore, reliability of
the compressor (53) can be improved.
[0158] Further, in the humidity control apparatus (10) of the
present embodiment, the electric expansion valve (55) of the
refrigerant circuit (50) is maintained in the fully open state
during the low-performance operation. Thus, sufficient flow rate of
the refrigerant which moves between the first adsorption heat
exchanger (51) and the second adsorption heat exchanger (52) during
the low-performance operation can be maintained, thereby making it
possible to increase the humidity control capability of the
humidity control apparatus (10) in the low-performance
operation.
[0159] --Variation of Embodiment--
[0160] In the humidity control apparatus (10) of the present
embodiment, the time interval between the switching operations of
the switching mechanism (40) for switching the flow path of the air
in the low-performance operation may be shorter than the time
interval between the switching operations of the switching
mechanism (40) for switching the flow path of the air in the
dehumidifying operation. That is, in the present embodiment, the
time interval between the switching operations of the switching
mechanism (40) for switching the flow path of the air in the
low-performance operation may be less than three minutes.
[0161] The amount of moisture exchanged between the adsorption heat
exchangers (51, 52) and the air passing therethrough abruptly
increases in a short time after supply of the air into the
adsorption heat exchangers (51, 52) starts, and gradually decreases
thereafter. In the humidity control apparatus (10) of the present
variation, the switching mechanism (40) switches the flow path of
the air alternately between the first path and the second path,
more frequently in the low-performance operation than in the
dehumidifying operation. Thus, in the present variation, the
humidity control capability of the humidity control apparatus (10)
in the low-performance operation can be improved.
[0162] Further, in the humidity control apparatus (10) of the
present embodiment, the degree of opening of the electric expansion
valve (55) of the refrigerant circuit (50) needs not to be the
fully open state during the low-performance operation. That is, the
degree of opening of the electric expansion valve (55) during the
low-performance operation may be set to a degree of opening which
can ensure sufficient flow rate of the refrigerant that moves
between the first adsorption heat exchanger (51) and the second
adsorption heat exchanger (52), and does not necessarily have to be
maintained in the fully open state.
INDUSTRIAL APPLICABILITY
[0163] As described above, the present disclosure is useful as a
humidity control apparatus which dehumidifies and humidifies air by
using an adsorption heat exchanger carrying an adsorbent.
DESCRIPTION OF REFERENCE CHARACTERS
[0164] 10 humidity control apparatus [0165] 25 exhaust fan [0166]
26 air supply fan [0167] 40 switching mechanism [0168] 50
refrigerant circuit [0169] 51 first adsorption heat exchanger
[0170] 52 second adsorption heat exchanger [0171] 53 compressor
[0172] 55 electric expansion valve (expansion valve) [0173] 90
controller
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