U.S. patent application number 15/320801 was filed with the patent office on 2017-06-08 for ventilation device.
This patent application is currently assigned to MITSUBISHI ELECTRIC CORPORATION. The applicant listed for this patent is MITSUBISHI ELECTRIC CORPORATION. Invention is credited to Hidemoto ARAI, Masahiro HASEGAWA, Fumio SAITO, Masami YASUDA.
Application Number | 20170159964 15/320801 |
Document ID | / |
Family ID | 55018670 |
Filed Date | 2017-06-08 |
United States Patent
Application |
20170159964 |
Kind Code |
A1 |
ARAI; Hidemoto ; et
al. |
June 8, 2017 |
VENTILATION DEVICE
Abstract
A ventilation device includes a temperature regulating coil that
is capable of changing the cooling capacity at multiple stages, and
that cools a supplied-air flow after having undergone total heat
exchange by a total heat exchanger, a target indoor-humidity
storage unit that stores therein a target indoor humidity that is a
target value of the indoor-air humidity, and a control unit that
decides the cooling capacity of the temperature regulating coil,
such that the humidity of the supplied-air flow becomes the target
indoor humidity, based on measurement values of an outside-air
temperature sensor and an outside-air humidity sensor when the
target indoor humidity is lower than an actual measurement value of
the indoor-air humidity measured by an indoor humidity sensor.
Inventors: |
ARAI; Hidemoto; (Tokyo,
JP) ; YASUDA; Masami; (Tokyo, JP) ; HASEGAWA;
Masahiro; (Tokyo, JP) ; SAITO; Fumio; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI ELECTRIC CORPORATION |
Chiyoda-ku, Tokyo |
|
JP |
|
|
Assignee: |
MITSUBISHI ELECTRIC
CORPORATION
Chiyoda-ku, Tokyo
JP
|
Family ID: |
55018670 |
Appl. No.: |
15/320801 |
Filed: |
July 4, 2014 |
PCT Filed: |
July 4, 2014 |
PCT NO: |
PCT/JP2014/067934 |
371 Date: |
December 21, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 2110/22 20180101;
F24F 2012/007 20130101; F24F 11/83 20180101; F24F 11/89 20180101;
F24F 12/006 20130101; F24F 2110/20 20180101; F24F 11/30 20180101;
F24F 2110/12 20180101; F24F 7/08 20130101 |
International
Class: |
F24F 12/00 20060101
F24F012/00; F24F 7/08 20060101 F24F007/08; F24F 11/00 20060101
F24F011/00 |
Claims
1. A ventilation device comprising: a casing that includes an
air-supply passage and an exhaust passage; an air-supply blower
that is provided in the air-supply passage, and that blows outdoor
air into the air-supply passage to form a supplied-air flow in a
room; an exhaust blower that is provided in the exhaust passage,
and that blows indoor air into the exhaust passage to form an
exhaust-air flow to be discharged outside a room; a total heat
exchanger that is located between the air-supply passage and the
exhaust passage, and accommodated in the casing, and that performs
total heat exchange between the supplied-air flow and the
exhaust-air flow; an outside-air temperature sensor that measures a
temperature of the outdoor air; an outside-air humidity sensor that
measures a humidity of the outdoor air; an indoor humidity sensor
that measures a humidity of the indoor air; a temperature
regulating coil that is capable of changing a cooling capacity at
multiple stages, and that dehumidifies the supplied-air flow after
having undergone total heat exchange by the total heat exchanger; a
target indoor-humidity storage unit that stores therein a target
indoor humidity that is a target value of a humidity of the indoor
air; and a control unit that decides a cooling capacity of the
temperature regulating coil, such that a humidity of the
supplied-air flow becomes the target indoor humidity, based on
measurement values of the outside-air temperature sensor and the
outside-air humidity sensor when the target indoor humidity is
equal to or higher than an actual measurement value of a humidity
of the indoor air measured by the indoor humidity sensor.
2. The ventilation device according to claim 1, wherein the control
unit stores therein reference data that defines the cooling
capacity to each combination of a temperature and a humidity of the
outside air, and determines a cooling capacity of the temperature
regulating coil based the reference data and outside-air
temperature and humidity sensor measurement results.
3. The ventilation device according to claim 1, wherein when an
actual measurement value of a humidity of the indoor air is higher
than the target indoor humidity, the control unit sets a capacity
value of the temperature regulating coil to 100%.
4. The ventilation device according to claim 1, wherein when the
indoor air is in an excessively-dehumidified state, the control
unit causes the temperature regulating coil to stop cooling the
supplied-air flow.
5. The ventilation device according to claim 1, wherein the target
indoor-humidity storage unit stores therein the target indoor
humidity as an absolute humidity, and the control unit calculates
an absolute humidity of the outdoor air based on an actual
measurement value of a temperature of the outdoor air measured by
the outside-air temperature sensor, and based on an actual
measurement value of a humidity of the outdoor air measured by the
outside-air humidity sensor, and when the target indoor humidity is
lower than the calculated absolute humidity, the control unit
determines a heating capacity of the temperature regulating coil,
such that a humidity of the supplied-air flow becomes the target
indoor humidity, based on measurement values of the outside-air
temperature sensor and the outside-air humidity sensor.
6. The ventilation device according to claim 1, wherein when the
ventilation device and air conditioners constitute an air
conditioning system, the control unit changes the target indoor
humidity based on number of the air conditioners in the air
conditioning system, which are performing a cooling operation.
Description
FIELD
[0001] The present invention relates to a ventilation device.
BACKGROUND
[0002] As described in Patent Literature 1, there has
conventionally been an air conditioner that controls a compressor
in an outdoor device by correcting the rotational speed of the
compressor according to the difference between the detected indoor
humidity and the indoor temperature during a dehumidifying
operation in the air conditioner, that also controls an outdoor fan
by correcting the rotational speed of the outdoor fan based on the
difference between the detected room temperature and the set indoor
temperature, and that performs a dehumidifying operation by
alternately performing the operation of the compressor and the
operation of the outdoor fan under the corrective control described
above.
[0003] Furthermore, as described in Patent Literature 2, there has
been a ventilation air conditioning device including a temperature
sensor that measures the outdoor-air temperature, a humidity sensor
that measures the outdoor-air humidity, an air conditioning coil
that heats the air to be supplied, and a control unit that controls
the air conditioning coil based on the measurement results of the
temperature sensor and the humidity sensor, in such a manner that
the absolute humidity of the air to be supplied reaches a
predetermined value.
CITATION LIST
Patent Literatures
[0004] Patent Literature 1: Japanese Patent No. 3720220
[0005] Patent Literature 2: International Publication No.
2012/077201
SUMMARY
Technical Problem
[0006] The technique described in Patent Literature 1 does not take
the outdoor temperature and humidity information, or an air
conditioning load due to ventilation into account. Therefore, the
overall air conditioning operation efficiency is not sufficiently
considered. This technique in Patent Literature 1 is not
sufficiently adequate for the total control in the air
conditioner.
[0007] In the technique described in Patent Literature 2,
parameters for controlling the air conditioning coil are limited to
the outside-air temperature and humidity. There is a case where at
the start of operation, the humidity in the room is low, and it is
therefore necessary to increase the amount of humidification. In
that case, when limitations are imposed on the capacity of the air
conditioning coil based on the outside-air temperature and humidity
conditions, a considerable amount of time is required to bring the
interior of the room into a comfortable humidity state. This
impairs the comfort.
[0008] The present invention has been achieved to solve the above
problems, and an object of the present invention is to provide a
ventilation device that performs an air supply with an optimal
amount of dehumidification at the time of introducing the outside
air by ventilation, and that is capable of performing an operation
that is less likely to cause a change in the indoor humidity.
Solution to Problem
[0009] In order to solve the above-mentioned problems and achieve
the object, according to an aspect of the present application,
there is provided a ventilation device including: a casing that
includes an air-supply passage and an exhaust passage; an
air-supply blower that is provided in the air-supply passage, and
that blows outdoor air into the air-supply passage to form a
supplied-air flow in a room; an exhaust blower that is provided in
the exhaust passage, and that blows indoor air into the exhaust
passage to form an exhaust-air flow to be discharged outside a
room; a total heat exchanger that is located between the air-supply
passage and the exhaust passage, and accommodated in the casing,
and that performs total heat exchange between the supplied-air flow
and the exhaust-air flow; an outside-air temperature sensor that
measures a temperature of the outdoor air; an outside-air humidity
sensor that measures a humidity of the outdoor air; an indoor
humidity sensor that measures a humidity of the indoor air; a
temperature regulating coil that is capable of changing a cooling
capacity at multiple stages, and that dehumidifies the supplied-air
flow after having undergone total heat exchange by the total heat
exchanger; a target indoor-humidity storage unit that stores
therein a target indoor humidity that is a target value of a
humidity of the indoor air; and a control unit that decides a
cooling capacity of the temperature regulating coil, such that a
humidity of the supplied-air flow becomes the target indoor
humidity, based on measurement values of the outside-air
temperature sensor and the outside-air humidity sensor when the
target indoor humidity is equal to or higher than an actual
measurement value of a humidity of the indoor air measured by the
indoor humidity sensor.
Advantageous Effects of Invention
[0010] According to the ventilation device of the present
invention, an effect is obtained where it is possible to perform an
air supply with an optimal amount of dehumidification at the time
of introducing the outside air by ventilation, and that is capable
of performing an operation that is less likely to cause a change in
the indoor humidity.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a top perspective view illustrating a
configuration of a ventilation device according to a first
embodiment of the present invention.
[0012] FIG. 2 is a flowchart illustrating an operation flow of the
ventilation device.
[0013] FIG. 3 is a flowchart illustrating a flow of initial
determination control.
[0014] FIG. 4 is a flowchart illustrating an operation flow in
steady operation control.
[0015] FIG. 5 is a time chart illustrating an example of an
operation of the ventilation device according to the first
embodiment.
[0016] FIG. 6 is a system diagram illustrating a configuration of a
ventilation device according to a second embodiment and air
conditioners.
[0017] FIG. 7 is a diagram illustrating a method for varying a high
sensible-heat ratio cooling-combining target indoor relative
humidity RHm_ken in the ventilation device according to the second
embodiment.
[0018] FIG. 8 is a flowchart illustrating an operation flow of the
ventilation device according to the second embodiment.
[0019] FIG. 9 is a time chart illustrating an example of an
operation of the ventilation device according to the second
embodiment.
DESCRIPTION OF EMBODIMENTS
[0020] Exemplary embodiments of a ventilation device according to
the present invention will be described below in detail with
reference to the accompanying drawings. The present invention is
not limited to the embodiments.
First Embodiment
[0021] FIG. 1 is a top perspective view illustrating a
configuration of a ventilation device according to a first
embodiment of the present invention. A ventilation device 23
includes a body casing 1, an exhaust blower 2, an air-supply blower
3, a total heat exchanger 4, a temperature regulating coil 5, a
humidifying element 6, an exhaust outlet 7, an air-supply outlet 8,
an air-supply inlet 9, an exhaust inlet 10, an outside-air
temperature sensor 11, an outside-air humidity sensor 12, a target
indoor-humidity storage unit 13, a control unit 14, a remote
controller 15, an air-passage switching damper 16, an indoor
temperature sensor 17, and an indoor humidity sensor 18.
[0022] In the ventilation device 23, the air-supply outlet 8 and
the exhaust inlet 10 are provided on the indoor side. On the
outdoor side, the exhaust outlet 7 and the air-supply inlet 9 are
provided. The ventilation device 23 has a box structure, and is
covered with the body casing 1. In the body casing 1, an air-supply
passage that communicates the air-supply inlet 9 on the outdoor
side with the air-supply outlet 8 on the indoor side, and an
exhaust passage that communicates the exhaust inlet 10 on the
indoor side with the exhaust outlet 7 on the outdoor side, are
formed.
[0023] The air-supply blower 3 is incorporated in the air-supply
passage to form a supplied-air flow. The exhaust blower 2 is
incorporated in the exhaust passage to form an exhaust-air flow.
The total heat exchanger 4 is located between the air-supply
passage and the exhaust passage. The total heat exchanger 4
continuously performs total heat exchange between a supplied-air
flow and an exhaust-air flow to convert the outdoor air to the air
to be supplied, and convert the indoor air to the air to be
exhausted. On the windward side of the air-supply outlet 8 within
the air-supply passage, the humidifying element 6 is provided.
Between the air-supply blower 3 and the humidifying element 6,
there is provided the temperature regulating coil 5 that
dehumidifies the air to be supplied, and adjusts the amount of
humidification. A water supply pipe 19 is connected to the
humidifying element 6. During the humidifying operation, a water
supply valve 20 is opened to supply water for humidification
through the water supply pipe 19 to the humidifying element 6.
[0024] A primary-side air passage through which an exhaust-air flow
passes, and a secondary-side air passage through which a
supplied-air flow passes, cross at a right angle inside the total
heat exchanger 4. Owing to this structure, the total heat is
exchanged between a supplied-air flow and an exhaust-air flow, and
therefore the total heat exchanger 4 can perform heat-exchange
ventilation.
[0025] On the windward side of the total heat exchanger 4 within
the exhaust passage, the air-passage switching damper 16 is
provided. The air-passage switching damper 16 switches between an
air passage 26 through which the air to be exhausted is delivered
to the total heat exchanger 4, and a bypass air passage 27 through
which the air to be exhausted is delivered directly to the exhaust
blower 2 not through the total heat exchanger 4. When the
air-passage switching damper 16 is closed, the exhaust air passes
through the total heat exchanger 4, and total heat exchange between
the exhaust air and the supplied air is continuously performed.
When the air-passage switching damper 16 is opened, the exhaust air
passes through the bypass air passage 27 provided beside the total
heat exchanger 4, and is then converted to the air to be exhausted,
and discharged outdoors by the exhaust blower 2.
[0026] When an outside-air temperature Toa is lower than the indoor
temperature in the transitional season, the ventilation device 23
operates in such a manner as to open the air-passage switching
damper 16 to deliver the indoor air to the bypass air passage 27 in
order to perform cooling with the outside air by bypass
ventilation. In the summer and winter season such as when an air
conditioning load is generated, the ventilation device 23 operates
in such a manner as to close the air-passage switching damper 16 to
deliver the indoor air to the total heat exchanger 4 in order to
perform total heat-exchange ventilation intended for the indoor-air
heat recovery.
[0027] The control unit 14 controls the ventilation operation. The
remote controller 15 receives a switching operation of operating
modes and the like. The target indoor-humidity storage unit 13 has
a target value of the indoor humidity stored therein.
[0028] The outside-air temperature sensor 11 measures the
outside-air temperature Toa. The outside-air humidity sensor 12
measures an outside-air humidity RHoa. The outside-air temperature
sensor 11 and the outside-air humidity sensor 12 are provided
between the air-supply inlet 9 and the total heat exchanger 4. The
indoor temperature sensor 17 measures an actual indoor temperature
Tra, that is, the temperature in the room. The indoor humidity
sensor 18 measures an actual indoor humidity RHra, that is, the
humidity in the room. The indoor temperature sensor 17 and the
indoor humidity sensor 18 are provided between the exhaust inlet 10
and the total heat exchanger 4.
[0029] The control unit 14 determines the heating capacity of the
temperature regulating coil 5 based on the temperature information
that is a measurement result of the outside-air temperature Toa
measured by the outside-air temperature sensor 11, and based on the
humidity information that is a measurement result of the
outside-air humidity RHoa measured by the outside-air humidity
sensor 12. The air having passed through the total heat exchanger 4
is heated by the temperature regulating coil 5. The air, having
been heated by the temperature regulating coil 5, passes through
the humidifying element 6, and is humidified, and then supplied
from the air-supply outlet 8 to the interior of the room. At this
time, the amount of humidification and the discharge-air
temperature are adjusted by the dehumidification amount in the
temperature regulating coil 5.
[0030] FIG. 2 is a flowchart illustrating an operation flow of the
ventilation device. After the start of operation, the control unit
14 executes initial determination control for determining the
initial operation state (Step S1). Thereafter, the control unit 14
shifts to steady operation control (Step S2). When there is no
operation to finish the device operation (NO at Step S3), the
control unit 14 continues the steady operation control. When there
is an operation to finish the device operation (YES at Step S3),
the control unit 14 finishes the operation of the ventilation
device 23.
[0031] FIG. 3 is a flowchart illustrating a flow of initial
determination control. Initially, the control unit 14 reads an
actual measured indoor relative humidity RHra, and a target indoor
relative humidity RHm (Step S11). Next, the control unit 14
compares the actual measured indoor relative humidity RHra with the
target indoor relative humidity RHm (Step S12). When the actual
measured indoor relative humidity RHra is higher than the target
indoor relative humidity RHm (YES at Step S12), the control unit 14
operates the ventilation device 23 in a dehumidifying mode A (Step
S13). In the dehumidifying mode A, in order to ensure the comfort,
the control unit 14 controls the temperature regulating coil 5 such
that the dehumidification capacity becomes 100%.
[0032] When the actual measured indoor relative humidity RHra is
lower than the target indoor relative humidity RHm (NO at Step
S12), the control unit 14 determines the humidity state in the room
(Step S14). The determination of the humidity state is performed
based on whether the actual measured indoor relative humidity RHra
is equal to or higher than a thermo-off humidity RHoff. When the
actual measured indoor relative humidity RHra is equal to or higher
than the thermo-off humidity RHoff, the control unit 14 determines
that it is necessary to continue the dehumidifying operation. In
order to prevent chattering, it is appropriate to set the
thermo-off humidity RHoff to a value that is approximately 5% lower
than the target indoor relative humidity RHm.
[0033] When the air in the room is in a state where it needs to be
dehumidified (YES at Step S14), the control unit 14 operates the
ventilation device 23 in a dehumidifying mode B (Step S15). In the
dehumidifying mode B, in order to maintain a constant indoor
humidity, the control unit 14 automatically determines the capacity
of the temperature regulating coil 5, at which the humidity of the
air supplied from the ventilation device 23 becomes the target
indoor relative humidity RHm, based on the outside-air temperature
Toa and the outside-air humidity RHoa. Reference data, in which a
combination of the outside-air temperature Toa and the outside-air
humidity RHoa is brought into correspondence with the capacity
value of the temperature regulating coil 5, that is a so-called
map, is held in the control unit 14. Based on the map, the control
unit 14 decides the capacity value of the temperature regulating
coil 5.
[0034] When the air in the room is not in a state where it needs to
be dehumidified, that is, when the actual measured indoor relative
humidity RHra is lower than the thermo-off humidity RHoff (NO at
Step S14), the control unit 14 operates the ventilation device 23
in a dehumidifying mode C (Step S16). In the dehumidifying mode C,
it is not necessary to promote dehumidification by using the
temperature regulating coil 5. In order to suppress the decrease in
discharge-air temperature, and condensation on the discharge
grille, which are caused by overcooling and dehumidification, the
control unit 14 sets the operation capacity of the temperature
regulating coil 5 to 0%, that is, the ventilation device 23
continues the dehumidifying operation in a thermo-off state.
[0035] In the dehumidifying mode C, the control unit 14 permits
only a heat-exchange ventilation operation, and prohibits a bypass
ventilation operation in which heat exchange is not performed.
Therefore, the ventilation device 23 can suppress an abrupt
decrease in humidity due to ventilation during the steady
operation, maintain a high-humidity state at a constant value for a
long time, and ensure the comfort.
[0036] FIG. 4 is a flowchart illustrating the operation flow in
steady operation control. First, the control unit 14 confirms which
dehumidifying mode the ventilation device 23 is currently in (Step
S21). When the current dehumidifying mode is the dehumidifying mode
A (the dehumidifying mode A at Step S21), the control unit 14
determines whether the actual measured indoor relative humidity
RHra remains higher than the target indoor relative humidity RHm
(Step S22). When the actual measured indoor relative humidity RHra
is higher than the target indoor relative humidity RHm (YES at Step
S22), the control unit 14 causes the ventilation device 23 to
continue the operation in the dehumidifying mode A in order to
continue to decrease the indoor humidity (Step S23). In contrast,
when the actual measured indoor relative humidity RHra is lower
than the target indoor relative humidity RHm (NO at Step S22), the
control unit 14 causes the ventilation device 23 to shift to the
dehumidifying mode B (Step S24). Due to this control, while
monitoring the outside-air temperature Toa and the outside-air
humidity RHoa, the control unit 14 operates the temperature
regulating coil 5 at an optimal coil-capacity value, and causes the
ventilation device 23 to continue the dehumidifying operation.
[0037] When the current dehumidifying mode is the dehumidifying
mode C (the dehumidifying mode C at Step S21), the control unit 14
determines whether the actual measured indoor relative humidity
RHra remains lower than the thermo-off humidity RHoff (Step S25).
When the actual measured indoor relative humidity RHra remains
lower than the thermo-off humidity RHoff (NO at Step S25), the
control unit 14 causes the ventilation device 23 to continue the
operation in the dehumidifying mode C (Step S26). When the actual
measured indoor relative humidity RHra is increased by ventilation,
and then becomes equal to or higher than the thermo-off humidity
RHoff (YES at Step S25), the control unit 14 causes the ventilation
device 23 to shift to the dehumidifying mode B (Step S24).
[0038] When the current dehumidifying mode is the humidifying mode
B (the dehumidifying mode B at Step S21), the control unit 14
determines whether the actual measured indoor relative humidity
RHra is equal to or higher than an unlimited-capacity return
humidity RHon (Step S27). When the actual measured indoor relative
humidity RHra is equal to or higher than the unlimited-capacity
return humidity RHon (YES at Step S27), the control unit 14 causes
the ventilation device 23 to shift to the dehumidifying mode A
(Step S23). In order to prevent chattering, it is appropriate to
set the unlimited-capacity return humidity RHon to a value that is
approximately 5% higher than the target indoor relative humidity
RHm.
[0039] When the actual measured indoor relative humidity RHra is
lower than the unlimited-capacity return humidity RHon (NO at Step
S27), the control unit 14 determines whether the actual measured
indoor relative humidity RHra is equal to or higher than the
thermo-off humidity RHoff (Step S28). When the actual measured
indoor relative humidity RHra is equal to or higher than the
thermo-off humidity RHoff (YES at Step S28), the control unit 14
maintains the operation of the ventilation device 23 in the
dehumidifying mode B (Step S24). When the actual measured indoor
relative humidity RHra is not equal to or higher than the
thermo-off humidity RHoff (NO at Step S28), the control unit 14
causes the ventilation device 23 to shift to the dehumidifying mode
C (Step S26).
[0040] FIG. 5 is a time chart illustrating an example of the
operation of the ventilation device according to the first
embodiment. At the time t0, the control unit 14 executes initial
determination control. Because the actual measured indoor relative
humidity RHra is higher than the target indoor relative humidity
RHm, the control unit 14 causes the ventilation device 23 to start
the dehumidifying operation in the humidifying mode A.
[0041] At the time t1, because the actual measured indoor relative
humidity RHra becomes equal to or lower than the target indoor
relative humidity RHm, the control unit 14 causes the ventilation
device 23 to shift from the dehumidifying mode A to the
dehumidifying mode B.
[0042] At the time t2, because the actual measured indoor relative
humidity RHra becomes equal to or lower than the thermo-off
humidity RHoff, the control unit 14 causes the ventilation device
23 to shift from the dehumidifying mode B to the dehumidifying mode
C.
[0043] At the time t3, because the actual measured indoor relative
humidity RHra becomes equal to or higher than the thermo-off
humidity RHoff, the control unit 14 causes the ventilation device
23 to shift from the dehumidifying mode C to the dehumidifying mode
B.
[0044] At the time t4, because the actual measured indoor relative
humidity RHra exceeds the unlimited-capacity return humidity RHon,
the control unit 14 causes the ventilation device 23 to shift from
the dehumidifying mode B to the dehumidifying mode A.
[0045] At the time t5, because the actual measured indoor relative
humidity RHra becomes equal to or lower than the target indoor
relative humidity RHm, the control unit 14 causes the ventilation
device 23 to shift from the dehumidifying mode A to the
dehumidifying mode B.
[0046] In the case where the current dehumidifying mode is the
dehumidifying mode B, as the outside-air humidity RHoa to be
introduced becomes lower, the indoor humidity may also decrease.
Therefore, in the above control, when the actual measured indoor
relative humidity RHra decreases to the thermo-off humidity RHoff,
the control unit 14 switches the dehumidifying mode of the
ventilation device 23 from the dehumidifying mode B to the
dehumidifying mode C.
[0047] In the case where the current dehumidifying mode is the
dehumidifying mode B, when the outside-air humidity RHoa to be
introduced becomes lower, the dehumidification capacity cannot keep
up with the lower outside-air humidity RHoa, and therefore the
actual measured indoor relative humidity RHra may increase.
Therefore, in the above control, when the actual measured indoor
relative humidity RHra is higher than the unlimited-capacity return
humidity RHon, the control unit 14 switches the dehumidifying mode
of the ventilation device 23 from the dehumidifying mode B to the
dehumidifying mode A. Due to this control, the ventilation device
23 performs an operation with the maximized amount of
dehumidification in order to decrease the indoor humidity as
quickly as possible.
[0048] When the actual measured indoor relative humidity RHra is
between the unlimited-capacity return humidity RHon and the
thermo-off humidity RHoff, the control unit 14 determines that the
indoor humidity falls within the target range, and causes the
ventilation device 23 to continue the energy-efficient humidifying
operation in the dehumidifying mode B.
[0049] In the above control, the target indoor relative humidity
RHm and the actual measured indoor relative humidity RHra are
measured and determined based on the relative humidity. However,
when the temperature at the measurement location is high, this may
result in an unintentional decrease in the relative humidity. In
this case, it is possible that the control unit 14 calculates an
absolute humidity from the actual measured indoor relative
temperature Tra and the actual measured indoor relative humidity
RHra, and compares the calculated absolute humidity with a target
absolute humidity.
[0050] As described above, according to the first embodiment, the
control unit 14 decides the capacity value of the temperature
regulating coil 5 based on the target indoor relative humidity RHm,
the actual measured indoor relative humidity RHra, the outside-air
temperature Toa, and the outside-air humidity RHoa, and the
ventilation device 23 performs dehumidification while appropriately
adjusting the dehumidification capacity. Due to this operation,
while maintaining a constant humidity in the room, the control unit
14 switches over the dehumidifying mode when the actual measured
indoor relative humidity RHra deviates from the target indoor
relative humidity RHm, and can make the actual measured indoor
relative humidity RHra closer to the target indoor relative
humidity RHm as quickly as possible. This can improve the comfort
in a shorter time.
Second Embodiment
[0051] A ventilation device according to a second embodiment has
the same configuration as in the first embodiment. However, when
the ventilation device is used in combination with an air
conditioner, the target indoor relative humidity RHm for the
ventilation device is changed based on the operation of the air
conditioner. FIG. 6 is a system diagram illustrating a
configuration of the ventilation device according to the second
embodiment and air conditioners.
[0052] Air conditioners 22 and the ventilation device 23 along with
an outdoor device 21 constitute an air conditioning system 50, and
are connected to each other by a refrigerant pipe 24 and a
communication line 25. The outdoor device 21 includes a pump that
delivers a refrigerant to the refrigerant pipe 24. The outdoor
device 21 further includes a fin that radiates heat absorbed by the
refrigerant during the cooling operation in the air conditioners 22
and the ventilation device 23. Some of the air conditioners 22
include a remote controller 28. An operation such as switching
between on and off of the device operation, or switching over the
operation mode, is performed through the remote controller 28.
[0053] As a target indoor humidity to be used when the air
conditioners 22 that constitute the air conditioning system 50
perform a high sensible-heat ratio cooling operation during a
dehumidifying operation, a high sensible-heat ratio
cooling-combining target indoor relative humidity RHm_ken is set in
the control unit 14. The high sensible-heat ratio cooling-combining
target indoor relative humidity RHm_ken is set to a value between a
normal target indoor relative humidity RHm and the thermo-off
humidity RHoff. It is also possible that the high sensible-heat
ratio cooling-combining target indoor relative humidity RHm_ken is
set to a fixed value, or a value that varies according to the
number of air conditioners that work in conjunction with each
other. FIG. 7 is a diagram illustrating a method for varying the
high sensible-heat ratio cooling-combining target indoor relative
humidity RHm_ken in the ventilation device according to the second
embodiment. It is also possible that the value of the high
sensible-heat ratio cooling-combining target indoor relative
humidity RHm_ken is set so as to become smaller each time the
number of the air conditioners 22 that work in conjunction with
each other increases by 1, or is set so as to become smaller each
time the number of the air conditioners 22 that work in conjunction
with each other increases by 2 or more.
[0054] FIG. 8 is a flowchart illustrating the operation flow of the
ventilation device according to the second embodiment. The
operation of the ventilation device 23 in initial determination
control (Step S1) is as described in the first embodiment. After
the initial determination control, the control unit 14 determines
whether the air conditioners 22 that constitute the air
conditioning system 50 perform a high sensible-heat ratio cooling
operation during a dehumidifying operation (Step S31). When the air
conditioners 22 perform a high sensible-heat ratio cooling
operation (YES at Step S31), the dehumidification capacity of the
air conditioners is decreased. Therefore, in order to maintain or
increase the dehumidification capacity of the ventilation device
23, the control unit 14 changes the target indoor relative humidity
RHm for the ventilation device 23 from the normal value to the high
sensible-heat ratio cooling-combining target indoor relative
humidity RHm_ken (Step S32). When the air conditioners 22 that
constitute the air conditioning system 50 perform a normal cooling
operation (NO at Step S31), a decrease in humidity due to cooling
and dehumidification can also be expected. Therefore, the control
unit 14 sets the normal value of the target indoor relative
humidity RHm as a target indoor humidity for the ventilation device
23 (Step S33).
[0055] Thereafter, a steady operation control is executed (Step
S2). The operation in the steady operation control is as described
in the first embodiment. After the steady operation control, when
there is no operation to finish the device operation (NO at Step
S3), it is returned to Step S31 and it is determined whether the
air conditioners 22 that constitute the air conditioning system 50
perform a high sensible-heat ratio cooling operation. When there is
an operation to finish the device operation (YES at Step S3), the
operation is finished.
[0056] As described above, when the air conditioners 22 do not
perform the high sensible-heat ratio cooling operation, the normal
value of the target indoor relative humidity RHm is set as a target
indoor relative humidity, and therefore an energy-efficient
dehumidifying operation is performed with the reduced capacity of
the temperature regulating coil 5.
[0057] FIG. 9 is a time chart illustrating an example of an
operation of the ventilation device according to the second
embodiment. At the time t10, the control unit 14 executes the
initial determination control, and causes the ventilation device 23
to start the operation in the humidifying mode A.
[0058] At the time t11, the actual measured indoor relative
humidity RHra becomes equal to or lower than the normal target
indoor relative humidity RHm, and also becomes equal to or lower
than the high sensible-heat ratio cooling-combining target indoor
relative humidity RHm_ken. Therefore, the control unit 14 causes
the ventilation device 23 to shift to the operation in the
dehumidifying mode B.
[0059] At the time t12, because the actual measured indoor relative
humidity RHra becomes equal to or lower than the thermo-off
humidity RHoff, the control unit 14 causes the ventilation device
23 to shift to the operation in the dehumidifying mode C.
[0060] At the time t13, because the actual measured indoor relative
humidity RHra becomes equal to or higher than the thermo-off
humidity RHoff, the control unit 14 causes the ventilation device
23 to shift from the dehumidifying mode C to the dehumidifying mode
B.
[0061] At the time t14, because the actual measured indoor relative
humidity RHra exceeds the unlimited-capacity return humidity RHon,
the control unit 14 causes the ventilation device 23 to shift from
the dehumidifying mode B to the dehumidifying mode A.
[0062] At the time t15, because the actual measured indoor relative
humidity RHra becomes equal to or lower than the high sensible-heat
ratio cooling-combining target indoor relative humidity RHm_ken,
the control unit 14 causes the ventilation device 23 to shift from
the dehumidifying mode A to the dehumidifying mode B.
[0063] Based on whether the air conditioners 22 perform a high
sensible-heat ratio cooling operation, the control unit 14 switches
between the normal target indoor relative humidity RHm and the high
sensible-heat ratio cooling-combining target indoor relative
humidity RHm_ken, and therefore can extend the area of the
dehumidifying mode A in which the temperature regulating coil 5
operates at the capacity value of 100%. This makes it possible to
suppress the decrease in humidity caused by dehumidification by the
air conditioners 22.
[0064] As described above, in the case where the ventilation device
23 is used in combination with the air conditioners 22, the target
indoor humidity for the ventilation device 23 is changed based on
the cooling-operation information and the refrigerant evaporating
temperature information. This makes it possible to prevent the air
in the room from being insufficiently dehumidified, and from being
overcooled, and therefore to improve the comfort in the room.
[0065] In the present embodiment, when the target indoor relative
humidity RHm is lower than the actual measured indoor relative
humidity RHra measured by the indoor humidity sensor 18, the
control unit 14 decides the cooling capacity of the temperature
regulating coil 5, such that the humidity of the supplied air
becomes the target indoor relative humidity RHm, based on the
measurement values of the outside-air temperature sensor 11 and the
outside-air humidity sensor 12. Therefore, the ventilation device
23 supplies an optimum amount of dehumidification at the time of
introducing the outside air by ventilation, and can achieve a
cooling and dehumidifying operation that is less likely to cause a
change in the indoor humidity.
INDUSTRIAL APPLICABILITY
[0066] As described above, the ventilation device according to the
present invention is useful in that the ventilation device that
humidifies the outside air, and that introduces the humidified air
into a room, changes the amount of humidification relative to a
target indoor humidity, and maintains a comfortable indoor
humidity. Particularly, the ventilation device according to the
present invention is suitable when a separate air conditioner is
provided in a room to constitute an air conditioning system along
with this ventilation device.
REFERENCE SIGNS LIST
[0067] 1 body casing, 2 exhaust blower, 3 air-supply blower, 4
total heat exchanger, 5 temperature regulating coil, 6 humidifying
element, 7 exhaust outlet, 8 air-supply outlet, 9 air-supply inlet,
10 exhaust inlet, 11 outside-air temperature sensor, 12 outside-air
humidity sensor, 13 target indoor-humidity storage unit, 14 control
unit, 15, 28 remote controller, 16 air-passage switching damper, 17
indoor temperature sensor, 18 indoor humidity sensor, 19 water
supply pipe, 20 water supply valve, 21 outdoor device, 22 air
conditioners, 23 ventilation device, 24 refrigerant pipe, 25
communication line, 26 air passage, 27 bypass air passage, 50 air
conditioning system.
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