U.S. patent application number 13/614305 was filed with the patent office on 2014-03-13 for air conditioning system.
This patent application is currently assigned to Mitsubishi Electric Corporation. The applicant listed for this patent is Hirotaka MASUI. Invention is credited to Hirotaka MASUI.
Application Number | 20140069131 13/614305 |
Document ID | / |
Family ID | 50231830 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140069131 |
Kind Code |
A1 |
MASUI; Hirotaka |
March 13, 2014 |
AIR CONDITIONING SYSTEM
Abstract
An air-conditioning system including an air-conditioning
apparatus having a compressor circulating a refrigerant, and an
outdoor unit and an indoor unit performing air conditioning of an
air-conditioned room; outside air introduction means supplying air
outside the air-conditioned room; outside air temperature detection
means detecting a temperature outside the air-conditioned room;
human body position detection means detecting a user in the
air-conditioned room; target-room-temperature determination means
determining a user number and/or a variation of the user number in
the air-conditioned room on the basis of the detection of the human
body position detection means and determining a target room
temperature; and cooling-operation-method determination means
determining whether to operate the air-conditioning apparatus or to
operate the outside air introduction means on the basis of the
target room temperature and the temperature outside the
air-conditioned room.
Inventors: |
MASUI; Hirotaka; (Cypress,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MASUI; Hirotaka |
Cypress |
CA |
US |
|
|
Assignee: |
Mitsubishi Electric
Corporation
Chiyoda-ku
JP
|
Family ID: |
50231830 |
Appl. No.: |
13/614305 |
Filed: |
September 13, 2012 |
Current U.S.
Class: |
62/180 |
Current CPC
Class: |
F24F 2011/0006 20130101;
F24F 11/30 20180101; F24F 11/62 20180101; F24F 2120/12 20180101;
F24F 11/65 20180101; F24F 2120/10 20180101 |
Class at
Publication: |
62/180 |
International
Class: |
F25B 49/02 20060101
F25B049/02; F25B 1/00 20060101 F25B001/00; F25D 17/06 20060101
F25D017/06 |
Claims
1. An air conditioning system, comprising: an air-conditioning
apparatus performing air conditioning of an air-conditioned space
by using a refrigerant discharged by a compressor; a fan supplying
air outside the air-conditioned space into the air-conditioned
space; an outside air temperature sensor detecting a temperature
outside the air-conditioned space; a heat source sensor detecting a
heat source object in the air-conditioned space;
target-room-temperature determination means determining a target
room temperature that is a temperature target of the
air-conditioned space by determining a user number and a variation
of the user number in the air-conditioned space based on a
detection of the heat source sensor; and cooling-operation-method
determination means determining whether to operate the
air-conditioning apparatus or to drive the fan based on the target
room temperature and the temperature outside the air-conditioned
space.
2. The air conditioning system of claim 1, wherein the
target-room-temperature determination means determines the target
room temperature from among three or more target room temperatures
that have been preset based on the user number and the variation of
the user number.
3. The air-conditioning system of claim 1, further comprising power
consumption determination means determining a power consumption of
the air-conditioning apparatus and a power consumption of the fan,
wherein the cooling-operation-method determination means determines
whether to operate the air-conditioning apparatus or to operate the
fan based on comparison of the power consumption of the
air-conditioning apparatus and the power consumption of the
fan.
4. The air conditioning system of claim 3, further comprising an
indoor air temperature sensor detecting a temperature inside the
air-conditioned space, wherein the power consumption determination
means determines, among the air-conditioning apparatus and the fan,
the power consumption of the apparatus and/or the fan in operation
by means of measurement, and the power consumption determination
means estimates and determines, among the air-conditioning
apparatus and the fan, the power consumption of the apparatus
and/or the fan not in operation based on the target room
temperature, the temperature outside the air-conditioned space, and
the temperature inside the air-conditioned space.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an air conditioning system
that air conditions an air-conditioned space.
[0003] 2. Description of the Related Art
[0004] In the related art, there is an air conditioning system that
performs a cooling/heating operation so that a comfortable
temperature is reached when a motion sensor detects presence of an
occupant in a room and that performs a low load operation when the
motion sensor detects no occupant in the room (see Patent
Literature 1, for example). Further, when a temperature of air
(outside air) of a non-air-conditioned space (outdoor) is lower
than a temperature of an air-conditioned space, a typical outside
air cooling operation performs a cooling operation, for example, by
suspending an operation of a compressor in order to stop an
operation performed with a refrigerant circuit and by introducing
the outside air into the conditioned space.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: Japanese Unexamined Patent Application
Publication No. 11-006644 (FIG. 1)
BRIEF SUMMERY OF THE INVENTION
Technical Problem
[0006] A known air conditioning system, such as the one in Patent
Literature 1, is capable of performing energy saving operations
while there is no occupant in a room; however, when there is an
occupant in the room, operation is performed with a fixed target
room temperature.
[0007] Here, a comfortable temperature for an occupant who has
entered the room from a hot outdoor area and a comfortable
temperature for an occupant who has been in the room for a long
time and is sufficiently cooled are, in most cases, different. If
the target room temperature is set low to suit the occupant who has
entered the room, it will be cold for the occupant who has been in
the room and it will cause energy to be lost due to over cooling.
Whereas, if the target room temperature is set high, it will be hot
for the former occupant, disadvantageously impairing
comfortability.
[0008] Further, although the outside air cooling operation does not
require the operation of the refrigerant circuit in which the
compressor is driven, when the outside air temperature is
relatively high without much difference with the target room
temperature, a large amount of outside air needs to be introduced
(supplied). Accordingly, conveyance power for the outside air
increases, resulting in increase of power consumption; hence,
energy saving is disadvantageously hindered. In particular, if the
outside air is introduced through a long duct, the conveyance power
loss is increased markedly. Further, when the outside air
temperature is excessively low, the outside air cooling operation
cannot be performed due to possibility of dew condensation and the
like. Accordingly, the range of the outside air temperature
allowing performance of the outside air cooling operation is
limited; hence, sufficient advantages are not obtained throughout
the year.
[0009] The invention addresses to the above disadvantages and an
object thereof is to provide an air conditioning system that is
capable of achieving energy saving while maintaining a temperature
corresponding to a state of the occupants in an air-conditioned
space.
Solution to Problem
[0010] An air-conditioning system of the invention includes an
air-conditioning apparatus that has a compressor that circulates a
refrigerant and that performs air conditioning of an
air-conditioned space; a fan that supplies air outside the
air-conditioned space; outside air temperature detection means that
detects a temperature outside the air-conditioned space; heat
source detection means that detects a heat source object in the
air-conditioned space;
target-room-temperature determination means that determines a user
number and/or a variation of the user number in the air-conditioned
space on the basis of a detection of the heat source detection
means and that determines a target room temperature that is a
temperature target of the air-conditioned space; and
cooling-operation-method determination means that determines
whether to operate the air-conditioning apparatus or to operate the
fan on the basis of the target room temperature and the temperature
outside the air-conditioned space.
Advantageous Effects of Invention
[0011] According to the invention, an energy saving operation using
the outside air can be performed while maintaining the temperature
to a temperature corresponding to the state of the occupants in the
air-conditioned space by determining the target room temperature on
the basis of the number of occupants in the air-conditioned space
and variation of the number thereof and by determining whether to
operate the air-conditioning apparatus or the fan on the basis of
the target room temperature and the like.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram illustrating an
air-conditioning system according to Embodiment 1 of the
invention;
[0013] FIG. 2 is a block diagram illustrating an air-conditioning
apparatus according to Embodiment 1 of the invention;
[0014] FIG. 3 is a diagram illustrating a relationship between
users of an air-conditioned room and a detection signal of human
body position detection means according to Embodiment 1 of the
invention;
[0015] FIG. 4 is a diagram illustrating a flowchart of a procedure
that is performed by target-room-temperature determination means
according to Embodiment 1 of the invention;
[0016] FIG. 5 is a diagram illustrating power consumed when outside
air introduction means is driven and when a refrigerant circuit is
operated;
[0017] FIG. 6 is a diagram related to a process of
cooling-operation-method determination means according to
Embodiment 1 of the invention and is a diagram illustrating the
relationship between the cooling operation, when the level of the
occupant number is high or when the level has been increased, and
the outside air temperature;
[0018] FIG. 7 is a diagram related to the process of the
cooling-operation-method determination means according to
Embodiment 1 of the invention and is a diagram illustrating the
relationship between the cooling operation, when the level of the
occupant number is low, intermediate, or zero, or when the level
has been decreased or there has been no change, and the outside air
temperature;
[0019] FIG. 8 is a schematic diagram illustrating an
air-conditioning system according to Embodiment 3 of the invention;
and
[0020] FIG. 9 is a diagram illustrating a flowchart of a procedure
that is performed by the cooling-operation-method determination
means according to Embodiment 3 of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Subsequently, Embodiments of the invention will be described
with reference to the drawings. Note that the configuration, the
operation, and the like of the air conditioning system of the
invention are not limited to those that are described in the
subsequent Embodiments.
Embodiment 1
[0022] FIG. 1 is a schematic diagram illustrating an
air-conditioning system according to Embodiment 1 of the invention.
Referring to FIG. 1, the air conditioning system of Embodiment 1
includes an air-conditioning apparatus having an outdoor unit 1 and
an indoor unit 3 connected by refrigerant pipes 2. The indoor unit
3 is disposed in an air-conditioned room 4. Further, the
air-conditioned room 4 is provided with outside air introduction
means 6 such as a fan, an outside air introduction duct 7, human
body position detection means (human body position detection
sensor) 5, and room temperature detection means (room temperature
detection sensor) 9. Furthermore, outside air temperature detection
means (outside air temperature detection sensor) 10 and a
controller 11 are provided outside the air-conditioned room 4.
[0023] FIG. 2 is a block diagram illustrating the air-conditioning
apparatus according to Embodiment 1 of the invention. The
air-conditioning apparatus includes a refrigerant circuit, which
circulates a refrigerant between the outdoor unit 1 and the indoor
unit 3, and performs air conditioning of the air-conditioned room
4. In Embodiment 1, description is given assuming that air
conditioning is performed with a cooling operation that cools the
air-conditioned room 4. As illustrated in FIG. 2, the outdoor unit
1 of Embodiment 1 includes various devices (means) such as a
compressor 101, a four-way valve 102, an outdoor side heat
exchanger 103, and an outdoor side fan 104.
[0024] The compressor 101 compresses and discharges the suction
refrigerant. Further, the outdoor side heat exchanger 103 exchanges
heat between the refrigerant and air (outdoor air). Here, the
outdoor side heat exchanger 103 of Embodiment 1 functions, for
example, as an evaporator during a heating operation; exchanges
heat between a low-pressure refrigerant, which has flowed therein
from the refrigerant pipe 2, and the air; and evaporates and
gasifies the refrigerant. Further, the outdoor side heat exchanger
103 functions as a condenser during a cooling operation; exchanges
heat between a refrigerant, which has flowed from the four-way
valve 102 side and that has been compressed in the compressor 101,
and air; and condenses and liquefies the refrigerant. Furthermore,
the outdoor side fan 104 sends in air from the outside of the
air-conditioned room 4 so that efficient heat exchange is performed
between the refrigerant and the air. The four-way valve 102
switches the flow of the refrigerant between a flow for a cooling
operation and a flow for a heating operation in accordance with an
instruction from the controller 11.
[0025] Meanwhile, the indoor unit 3 includes an indoor side heat
exchanger 301, and indoor side expansion device (expansion valve)
302, and an indoor side fan 303. The indoor side heat exchanger 301
exchanges heat between the refrigerant and the air in the
air-conditioned room 4. The indoor side heat exchanger 301
functions, for example, as a condenser during a heating operation;
exchanges heat between the refrigerant, which has flowed therein
from the refrigerant pipe 2, and the air; condenses and liquefies
(or into a two-phase gas-liquid state) the refrigerant, and makes
the refrigerant flow out therefrom. The indoor side heat exchanger
301 functions as an evaporator during a cooling operation;
exchanges heat between the refrigerant, which has been turned into
a low-pressure state with the indoor side expansion device 302, and
the air; evaporates and gasifies the refrigerant by having the
refrigerant remove heat from the air; and makes the refrigerant
flow out therefrom. Further, the indoor unit 3 is provided with the
indoor side fan 303 to control the flow of air that performs heat
exchange.
[0026] The human body position detection means 5 serving as a heat
source sensor is, for example, an infrared sensor. For example, the
human body position detection means 5 scans the entire
air-conditioned room 4, detects a two-dimensional temperature
distribution of the entire air-conditioned room 4, and transmits a
signal to the controller 11. Here, although the human body position
detection means 5 scans and detects the two-dimensional temperature
distribution of the entire air-conditioned room 4, the invention is
not limited to this. For example, an array of infrared sensors may
constitute the human body position detection means 5 such that
detection of the two-dimensional temperature distribution of the
entire air-conditioned room 4 is carried out without any
scanning.
[0027] The room temperature detection means 9 that serves as an
indoor air temperature sensor detects the air temperature in the
air-conditioned room 4 and transmits a signal to the controller 11.
Further, the outside air temperature detection means 10 that serves
as an outside air temperature sensor detects the air (outside air)
temperature (outside air temperature) outside the air-conditioned
room 4 and transmits a signal to the controller 11.
[0028] The outside air introduction means 6 includes a fan, drives
the fan, and sends outside air into the air-conditioned room 4 from
the outside of the air-conditioned room 4 through the outside air
introduction duct 7.
[0029] Each signal line 8 is a line for communicating with the
controller 11. Here, in Embodiment 1, a signal line 8a is a line
for transmitting a signal related to a detection of the outside air
temperature detection means 10. A signal line 8b is a line for
communicating between the indoor unit 3 and the controller 11. A
signal line 8c is a line for transmitting a signal related to a
detection of the room temperature detection means 9. A signal line
8d is a line for transmitting a signal related to a detection of
the human body position detection means 5. A signal line 8e is a
line for communicating between the outside air introduction means 6
and the controller 11.
[0030] The controller 11 controls each of the components of the air
conditioning system. In Embodiment 1, the controller 11 includes
target-room-temperature determination means 12 and
cooling-operation-method determination means 13. The
target-room-temperature determination means 12 performs a
determination process of the target room temperature in the
air-conditioned room 4 in correspondence with the signal sent from
the human body position detection means 5. Details of the process
will be described below. Further, the cooling-operation-method
determination means 13 performs a determination process of whether
to perform a cooling operation with the air-conditioning apparatus
(refrigerant circuit) or to perform an outside air cooling
operation that makes the outside air flow into the air-conditioned
room 4 from the outside air introduction means 6 on the basis of
the target room temperature that the target-room-temperature
determination means 12 has determined and the outside air
temperature related to the detection of the outside air temperature
detection means 10. Furthermore, the operation of each component is
controlled such that the room temperature related to the detection
of the room temperature detection means 9 becomes a target room
temperature that the target-room-temperature determination means 12
has determined.
[0031] FIG. 3 is a diagram illustrating relationships between users
20 (20a, 20b, 20c, 20d) of the air-conditioned room 4 and detection
signals of the human body position detection means 5 according to
Embodiment 1 of the invention. Referring first to FIG. 3(a), a case
in which no user 20 is present in the air-conditioned room 4 will
be described. When there is no user 20, the signal strength of a
vertically oriented output signal 21, which is a signal in the
vertical direction (height direction) of the air-conditioned room,
remains at zero (level zero) as shown with a vertically oriented
output signal 21a. Further, as for a horizontally oriented output
signal 22 in the horizontal direction of the air-conditioned room
4, the signal strength remains at zero, as shown with a
horizontally oriented output signal 22a.
[0032] Referring next to FIG. 3(b), a case in which users 20 are
present in the air-conditioned room 4 will be described. As
illustrated in FIG. 3(b), there are three users, namely, user 20b,
user 20c, and user 20d, in the air-conditioned room 4, for example.
At this time, a vertically oriented output signal 21b has three
high-signal-level portions where the signal strengths are strong,
each corresponding to the height of the users 20b, 20c, and 20d,
respectively. Further, a horizontally oriented output signal 22b
also has three portions where the signal levels are high, each
corresponding to the positions of the users 20b, 20c, and 20d,
respectively. Note that either one of the vertically oriented
output signal 21 and the horizontally oriented output signal 22 may
detect the user 20. In Embodiment 1, the human body position
detection means 5 is provided in the ceiling of the air-conditioned
room 4. The human body position detection means 5 transmits the
horizontally oriented output signal 22b to the controller 11.
[0033] FIG. 4 is a diagram illustrating a flowchart of a procedure
that is performed by the target-room-temperature determination
means 12 according to Embodiment 1 of the invention. Referring to
FIG. 4, the process of the target-room-temperature determination
means 12 will be described. Here, the target-room-temperature
determination means 12 presets and stores threshold values that are
needed to perform the determination and the like as initial values.
For example, the level of occupant number in the air-conditioned
room 4 is set. Here, the level of occupant number is set to three
levels, namely, low, intermediate, and high. Further, as boundary
values of the total area of the heat source object, area 1 and area
2 each serving as a predetermined area value is set. Here, the
total heat-source-object area is determined on the basis of the
summation of the high-signal-level portions of the horizontally
oriented output signal 22b illustrated in FIG. 3.
[0034] Further, in Embodiment 1, the target room temperature is set
to a target room temperature for large occupant number when the
level of occupant number is high or when the level of occupant
number has increased from the preceding determination. Furthermore,
the target room temperature is set to a target room temperature for
small occupant number when the level of occupant number is low,
intermediate, or zero, as well as when the level of occupant number
has decreased or has not changed.
[0035] First, in step 1, the temperature distribution of the entire
air-conditioned room 4 is determined on the basis of the signal
transmitted from the human body position detection means 5.
Further, in step 2, the total area (total heat-source-object area)
of the heat source object (user 20) is calculated on the basis of
the temperature distribution.
[0036] Next, in step 3, the level of occupant number is determined
by comparing the total heat-source-object area and the
aforementioned boundary values. For example, [0037] when total
heat-source-object area=0, then the level of occupant number is
determined to be zero; [0038] when 0<total heat-source-object
area<area 1, then the level of occupant number is determined to
be low; [0039] when area 1.ltoreq.total heat-source-object
area<area 2, then the level of occupant number is determined to
be intermediate; and [0040] when 2.ltoreq.total heat-source-object
area, then the level of occupant number is determined to be
high.
[0041] In step 4, it is determined whether the level of occupant
number is high on the basis of the determination result. When it is
determined to be high, step 6 is processed. When it is determined
to be not high (the level of occupant number is zero, low, or
intermediate), step 5 is processed. Further, in step 5, it is
determined whether the level of occupant number has increased from
the preceding determination (scan). When it is determined that the
level of occupant number has increased, step 6 is processed. When
it is determined that the level of occupant number has not
increased (decrease in level or no change), step 7 is processed.
Here, increase in the level of occupant number refers to such a
case where the preceding level of occupant number that had been
determined to be zero is determined to be low, intermediate, or
high, for example. Further, there is a case where the preceding
level of occupant number that had been determined to be low is
determined to be intermediate or high. Furthermore, there is a case
where the preceding level of occupant number that had been
determined to be intermediate is determined to be high.
[0042] After the target room temperature for large occupant number,
which has been set when the level of occupant number is high or
when the level of occupant number has increased, is determined as
the target room temperature in step 6, the process returns to step
1. On the other hand, after the target room temperature for small
occupant number--having been set when the level of occupant number
is low, intermediate, or zero, or when the level of occupant number
has decreased or has not changed--is determined as the target room
temperature in step 7, the process returns to step 1. The
target-room-temperature determination means 12 determines the
target room temperature in the air-conditioned room 4 by performing
the above process.
[0043] Here, the cooling capacity of the outside air that is
introduced into the air-conditioned room 4 by the outside air
introduction means 6 can be expressed by the following equation
(1). As in equation (1), the cooling capacity can be expressed as a
function F1 that is a value obtained by multiplying the air volume
to the temperature difference between the target room temperature
and the outside air temperature. It can be understood from equation
(1) that when the temperature difference between the target room
temperature and the outside air temperature is small, larger air
volume is required to obtain the same cooling capacity.
Cooling capacity=F1(air volume.times.(target room
temperature-outside air temperature)) (1)
[0044] Further, power consumption of the outside air introduction
means 6 can be expressed by the following equation (2). As in
equation (2), the power consumption of the outside air introduction
means 6 can be expressed as a function F2 of the air volume.
Accordingly, it can be understood that power consumption increases
when air volume is increased.
Power consumption of the fan=F2 (air volume) (2)
[0045] FIG. 5 is a diagram illustrating power consumed when the
outside air introduction means 6 is driven and when the
air-conditioning apparatus is operated. Referring to FIG. 5, the
axis of ordinates represents the power consumption, and the axis of
abscissas represents the air volume of the outside air introduction
means 6. Line 31, representing the power consumption of the outside
air introduction means 6 while in operation, shows that the power
consumption increases when the air volume of the outside air
introduction means 6 increases. On the other hand, Line 32
represents the power consumption of the air-conditioning apparatus
(refrigerant circuit) while in operation. The power consumption is
mainly that of the driven compressor 101 although it including the
power consumption of the driven outdoor side fan 104. As shown in
FIG. 5, the power consumption of the air-conditioning apparatus
while in operation is substantially constant irrespective of the
air volume of the outside air introduction means 6. Further, FIG. 5
shows that the power consumption is lower when the outside air
introduction means 6 is operated in the region on the left side of
the intersection point between line 31 and line 32 and the power
consumption is higher when the outside air introduction means 6 is
operated in the region on the right side of the intersection
point.
[0046] FIG. 6 is a diagram related to the process of the
cooling-operation-method determination means 13 according to
Embodiment 1 of the invention and is a diagram illustrating the
relationship between the cooling operation, when the level of the
occupant number is high or when the level has been increased, and
the outside air temperature. Here, as an example, the target room
temperature determined by the target-room-temperature determination
means 12 is set to the target room temperature for large occupant
number (22.degree. C.). Further, each of T1, T2, T3, T4, and T5
represents a temperature range of the outside air temperature.
Here, T1 is the lowest temperature range. The temperature range
becomes higher in the order of T2, T3, and T4, and T5 is the
highest temperature range. Here, the temperature within the
temperature range T4 is lower than the target room temperature, and
the temperature within the temperature range T5 is higher than the
target room temperature.
[0047] For example, when outside air with a temperature within the
lowest temperature range T1 is introduced into the air-conditioned
room 4, there is a possibility of dew condensation caused by
increase in the relative humidity of air in the area where the air
in the air-conditioned room 4 is cooled by mixing of the air in the
air-conditioned room and the outside air. Accordingly, there is a
possibility of dew condensation water that has occurred near the
air outlet of the outside air introduction duct 7 flowing into the
air-conditioned room 4; hence, outside air cooling operation cannot
be performed. For example, in a case where the temperature in the
air-conditioned room 4 is higher than the target room temperature
due to heat emitted from heat sources such as OA equipment and the
like, even if the outside air temperature is low, a cooling
operation with the air-conditioning apparatus is performed.
[0048] Further, when the temperature of outside air is within the
temperature range T2, which is a temperature that is in the low
temperature region but has no risk of dew condensation, cooling
effect can be obtained by introducing outside air with a small
volume, that is, with a small air volume (introduction volume of
outside air), into the air-conditioned room 4. Further, when the
temperature of outside air is within the temperature range T3,
which is a temperature that is a little higher than that of the
temperature range T2, the temperature difference between the target
room temperature is smaller compared to that of the outside air in
the temperature range T2. Accordingly, based on the aforementioned
equation (1), a cooling effect can be obtained by introducing
outside air with an intermediate air volume, which has more air
volume than the small air volume, into the air-conditioned room
4.
[0049] Furthermore, when the temperature of outside air is within
the temperature range T4, which is a temperature that is a little
higher than that of the temperature range T3, the temperature
difference between the target room temperature is smaller still
compared to that of the outside air in the temperature range T3.
The air volume may be further increased to maintain the cooling
capacity; however, as shown in FIG. 5, if the power consumed in the
operation of the outside air introduction means 6 exceeds the power
consumed by the operation of the air-conditioning apparatus, then
the cooling operation with the air-conditioning apparatus will be
more energy saving. Accordingly, the compressor 101 is driven and
cooling operation is performed with the air-conditioning apparatus
when the outside air temperature is within the temperature range
T4. When the outside air temperature is within the highest
temperature range T5, it will not be possible to perform cooling
that introduces outside air since the outside air will heat the air
in the air-conditioned room 4. Accordingly, the compressor 101 is
driven and a cooling operation with the air-conditioning apparatus
is performed.
[0050] FIG. 7 is a diagram related to the process of the
cooling-operation-method determination means 13 according to
Embodiment 1 of the invention and is a diagram illustrating the
relationship between the cooling operation--when the level of the
occupant number is low, intermediate, or zero, or when the level
has been decreased or there has been no change--and the outside air
temperature. Here, as an example, the target room temperature
determined by the target-room-temperature determination means 12 is
set to the target room temperature for small occupant number
(25.degree. C.). The relationships between T1 to T5 are the same as
FIG. 6.
[0051] Since the target room temperature is set high, the cooling
capacity can be small. Accordingly, as regards the outside air with
a temperature in the temperature ranges T2, T3, and T4, for
example, if the temperature difference between the target room
temperature and the outside air temperature is the same, from the
aforementioned equation (1), the air volume of the fan of the
outside air introduction means can be small. For example, in
comparison with FIG. 6, when the outside air temperature is a
temperature in the temperature range T2, the temperature difference
becomes larger than that of FIG. 6, and a cooling effect can be
obtained by introducing outside air with a minute air volume into
the air-conditioned room 4 rather than a small air volume. Further,
also in the case in which the outside air temperature is a
temperature in the temperature range T3, since the temperature
difference is large, a cooling effect can be obtained by
introducing outside air with a small air volume into the
air-conditioned room 4 rather than an intermediate air volume.
Furthermore, when the outside air temperature is a temperature in
the temperature range T4, operation of the air-conditioning
apparatus is performed in FIG. 6; however, in FIG. 7, outside air
cooling operation can be performed since the operation of the
outside air introduction means 6 consumes smaller power than the
driving of the compressor 101 and the operation of the
air-conditioning apparatus.
[0052] As above, according to the air conditioning system of
Embodiment 1, since the target-room-temperature determination means
12 determines the target room temperature on the basis of the
number of users in the air-conditioned room 4 and the variation of
the number thereof, and since the cooling-operation-method
determination means 13 determines whether to operate the outdoor
unit 1 and the indoor unit 3 or to operate the outside air
introduction means 6 on the basis of the target room temperature
and the outside air temperature, an energy saving operation using
the outside air can be performed while maintaining the temperature
to a temperature corresponding to the state of the user(s) 20 in
the air-conditioned room 4.
Embodiment 2
[0053] In the above-mentioned Embodiment 1, the
target-room-temperature determination means 12 determines the
target room temperature from the two, the target room temperature
for large occupant number and the target room temperature for small
occupant number; however, the invention is not limited to the
above. For example, the target room temperature may be determined
from among three or more set target room temperatures, on the basis
of the signal of the human body position detection means 5.
Embodiment 3
[0054] FIG. 8 is a schematic diagram illustrating an
air-conditioning system according to Embodiment 3 of the invention.
Referring to FIG. 8, components and the like attached with like
reference numerals serves similar roles as that in Embodiment 1. As
illustrated in FIG. 8, the cooling-operation-method determination
means 13 includes power consumption determination means 16. The
power consumption determination means 16 determines the power
consumption of the compressor 101 on the basis of the refrigerant
discharge pressure and the discharge temperature of the compressor
101, the rotation speed of the compressor 101, and the like.
Further, the power consumption determination means 16 determines
the power consumption of the outside air introduction means 6.
Thus, the power consumption determination means 16 has tabular
data, for example, that shows the relationship between the power
consumption and the discharge pressure of the refrigerant, the
discharge temperature of the refrigerant, the rotation speed of the
compressor 101, and the like. Similarly, the power consumption
determination means 16 has tabular data, for example, that shows
the relationship between the power consumption and the air volume,
the rotation speed, and the like of the outside air introduction
means 6.
[0055] FIG. 9 is a diagram illustrating a flowchart of a procedure
that is performed by the cooling-operation-method determination
means 13 according to Embodiment 3 of the invention. The processing
operation of the cooling-operation-method determination means 13
provided with the power consumption determination means 16 will be
described with reference to FIG. 9.
[0056] In step 20, it is determined whether the compressor 101 is
driven (whether the air-conditioning apparatus is in operation).
When it is determined that the compressor 101 is being driven, the
process proceeds to step 21. When it is determined that the
compressor 101 is not being driven, the process proceeds to step
26. In step 21, the current refrigerant discharge pressure and the
current refrigerant discharge temperature of the compressor 101 and
the current rotation speed of the compressor 101 is measured. For
the measurement, pressure detection means, temperature detection
means, and the like are disposed in the discharge side pipe or the
like. Further, in step 22, the power consumption determination
means 16 determines the current power consumption of the
air-conditioning apparatus (mainly the compressor 101) on the basis
of the aforementioned data. In this example, the power consumed by
the air-conditioning apparatus is determined on the basis of both
data associated with the compressor 101 which consumes majority of
the power and a fixed value or values added for the other
components; however, its determination may be performed by
including the power consumption obtained by measuring or the like
the power consumption of the other components, such as the outdoor
side fan 104.
[0057] In step 23, the air volume and the rotation speed of the
outside air introduction means 6, which are required in order to
obtain the cooling capacity during the outside air cooling
operation, are calculated and determined on the basis of the
temperature difference between the current outside air temperature
and the target room temperature. Further, in step 24, the power
consumed by the operation of the outside air introduction means 6
is estimated and determined on the basis of the above-mentioned
equation (2), for example.
[0058] In step 25, the calculated power consumption of the
compressor 101 and the estimated power consumption of the operation
of the outside air introduction means 6 are compared. Further, when
it is determined that the power consumption of the compressor 101
is larger than the power consumed by the operation of the outside
air introduction means 6, the process proceeds to step 26.
Furthermore, when it is determined that the power consumption of
the operation of the air-conditioning apparatus is not larger than
the power consumed by the operation of the outside air introduction
means 6 (the power consumption of the air-conditioning apparatus is
equivalent to or smaller than the power consumed by the operation
of the outside air induction means 6), the process proceeds to step
30. In step 26, outside air cooling operation is performed. On the
other hand, in step 30, the compressor 101 is driven and the
cooling operation with the air-conditioning apparatus is performed,
and the process proceeds to step 20.
[0059] In step 27, the power consumption determination means 16
calculates and determines the current power consumption of the
outside air introduction means 6 on the basis of the current
rotation speed of the outside air introduction means 6 and the
relationship between the current rotation speed of the outside air
introduction means 6 and the power consumption. Further, in step
28, the power consumption of the compressor 101 is estimated and
determined on the basis of the current room temperature, the target
room temperature, and the current outside air temperature and on
the basis of the data of the room temperature, the target room
temperature, the outside temperature, the pressure, the
temperature, the rotation speed, and the power consumption of the
compressor 101. In step 29, it is determined whether the power
consumption of the outside air introduction means 6 is equivalent
to or larger than the power consumption of the air-conditioning
apparatus. When it is determined that the power consumption of the
outside air introduction means 6 is not equivalent to or larger
than the power consumption of the air-conditioning apparatus (the
power consumption of the air-conditioning apparatus is larger), the
process proceeds to step 26 and outside air cooling operation is
performed. On the other hand, when it is determined that the power
consumption of the outside air introduction means 6 is equivalent
to or larger than the power consumption of the air-conditioning
apparatus, the process proceeds to step 30. Further, in step 30,
the cooling operation with the air-conditioning apparatus is
performed, and the process proceeds to step 20.
[0060] As above, according to the air conditioning system of
Embodiment 3, the power consumption determination means 16
determines the power consumption of the outside air introduction
means 6 and the power consumption of the air-conditioning apparatus
by measurement and estimation, directly compares each power
consumption with each other, and determines whether the outside air
introduction means 6 or the air-conditioning apparatus (compressor
101) is to be operated; hence, determination of energy saving
operations with higher precision can be made.
Embodiment 4
[0061] In the above-mentioned Embodiments including Embodiment 1,
the target room temperature is set such that the target room
temperature for small occupant number is higher than the target
room temperature for large occupant number; however, the invention
is not limited to the above setting and any target room temperature
may be set. Further, conditions such as a schedule may be
added.
[0062] For example, in an office and the like, in the morning and
evening when there is heavy traffic of people entering and exiting
the office, even if the number of occupants decreases, the target
room temperature may be set so as not to be increased since there
is a large amount of activity going on, On the other hand, during
the daytime when the office is occupied by office workers working
at desks, the target room temperature is set such that the target
room temperature for small occupant number is higher than the
target room temperature for large occupant number, thus achieving
energy saving.
[0063] Further, for example, at an event site and the like, the
target room temperature is set not to be changed even in the
daytime. In addition, typically, since the outside air temperature
in the night drops and the air conditioning load decreases, the
target room temperature may be set on the basis of the number of
occupants and thus achieve energy saving.
[0064] Furthermore, in the above-mentioned Embodiments including
Embodiment 1, the power consumption of each of the compressor 101
and the outside air introduction means 6 is calculated on the basis
of preset data; however, a watt-hour meter may be provided
measuring each power consumption, for example.
[0065] Additionally, in the above-mentioned Embodiments including
Embodiment 1, criteria for the target room temperature
determination were temperatures related to the detection of the
room temperature detection means 9 and the outside air temperature
detection means 10; however, the invention is not limited to the
above criteria. For example, humidity detection means may be
provided inside/outside the air-conditioned room 4 and the enthalpy
inside/outside the air-conditioned room 4 may be calculated as data
for determining the target room temperature.
[0066] Furthermore, in the above-mentioned Embodiments including
Embodiment 1, the target room temperature is determined on the
basis of the signal from the human body position detection means 5
and in correspondence with the state of the user(s) 20 in the
air-conditioned room 4. However, clocking means may be further
provided that provides delay time such that the target room
temperature is reduced and high cooling is set for a set time
period when it is once determined that the user 20 has
increased.
REFERENCE SIGNS LIST
[0067] 1 outdoor unit; 2 refrigerant pipe; 3 indoor unit; 4
air-conditioned room; 5 human body position detection means; 6
outside air introduction means; 7 outside air introduction duct; 8,
8a, 8b, 8c, 8d, 8e signal line; 9 room temperature detection means;
10 outside air temperature detection means; 11 controller; 12
target-room-temperature determination means; 13
cooling-operation-method determination means; 16 power consumption
determination means; 20, 20a, 20b, 20c, 20d user; 21, 21a, 21b
vertically oriented output signal; 22, 22a, 22b horizontally
oriented output signal; 31 line representing power consumption when
outside air introduction means 6 is driven; 32 line representing
power consumption when compressor 101 is driven; 101 compressor;
102 four-way valve; 103 outdoor side heat exchanger; 104 outdoor
side fan; 301 indoor side heat exchanger; 302 indoor side expansion
device; 303 indoor side fan; 300 indoor unit.
* * * * *