TECHNICAL FIELD
[0001] The present invention relates to a radiator that cools by sucking in cold water from
a heat source unit.
BACKGROUND ART
[0002] In the conventional art, a radiator that cools an indoor space is known wherein cold
water is sucked from a heat source unit into a heat exchanger. For example, Patent
Document 1 (i.e., Japanese Unexamined Patent Application Publication No.
2002-98344) discloses a radiator in an air conditioning system, wherein the radiator comprises
a heat exchange coil (corresponding to the heat exchanger) and a ventilation fan.
This air conditioning system cools by supplying cold water to the heat exchange coil
(which corresponds to the heat exchanger).
[0003] Further, an air conditioner including a first temperature sensor configured to measure
an indoor temperature during a heating operation, a second temperature sensor configured
to measure a discharge temperature of a compressor, a valve provided at an outlet
side of an indoor heat exchanger during the heat operation, and a controller configured
to control an opening of the valve by comparing a temperature detected by the first
temperature sensor with a temperature detected by the second temperature sensor is
disclosed in
EP 2 039 508 A1.
US 2004/0182944 A1 discloses a cooling ceiling installation with at least one heat exchanger, a valve
which controls the flow of a heat transfer medium through the heat exchanger and a
mechanical control device, and a monitoring device. The monitoring device has an adjustment
drive which mechanically displaces the control device to a state in which the valve
is closed, to avoid a condensate formation on the cooling ceiling installation.
SUMMARY OF THE INVENTION
<Technical Problem>
[0004] Nevertheless, in the air conditioning system disclosed in Patent Document 1, the
cold water is supplied to the heat exchange coil such that an indoor temperature or
an outdoor temperature reaches a preset set temperature. Consequently, if, for example,
the temperature of the cold water supplied to the heat exchange coil is lower than
the dew point temperature of the air in the indoor space, then there is a risk that
condensation will be formed in the heat exchanger.
[0005] Accordingly, an object of the present invention is to provide a radiator that can
reduce the risk that condensation will form in the heat exchanger.
<Solution to Problem>
[0006] A radiator according to a first aspect of the present invention is a radiator that
cools an indoor space by sucking in cold water from a heat source unit and comprises
a heat exchanger, a first piping, a flow volume adjusting mechanism, a heat exchanger
temperature detection unit, and a control unit. In the first piping, the cold water
flows from the heat source unit side to the heat exchanger side. The flow volume adjusting
mechanism adjusts the flow volume of the cold water flowing through the heat exchanger.
The heat exchanger temperature detection unit is capable of detecting the temperature
of the heat exchanger. The control unit performs a first cooling control that controls
the flow volume adjusting mechanism so that the temperature of the heat exchanger
detected by the heat exchanger temperature detection unit is greater than or equal
to the dew point temperature of air inside the indoor space.
[0007] In the radiator according to the invention, the first cooling control is performed
by the control unit. Consequently, if the first cooling control is performed, then
it is possible to reduce the risk that the temperature of the heat exchanger during
cooling of the indoor space will fall below the dew point temperature of the air inside
the indoor space.
[0008] Thereby, it is possible to reduce the risk that condensation will form in the heat
exchanger.
[0009] The radiator according to the present invention is the radiator wherein the flow
volume adjusting mechanism is capable of assuming a blocked state, wherein the flow
of the cold water from the heat source unit side to the heat exchanger side is blocked.
In addition, in the first cooling control, the control unit switches the flow volume
adjusting mechanism to the blocked state if the temperature of the heat exchanger
that is detected by the heat exchanger temperature detection unit is lower than the
dew point temperature of the air inside the indoor space. Consequently, if the temperature
of the heat exchanger is lower than the dew point temperature of the air inside the
indoor space, then the flow of the cold water from the heat source unit to the heat
exchanger can be blocked. Accordingly, it is possible to reduce the risk of a further
decrease in the temperature of the heat exchanger resulting from the continuation
of the flow of the cold water into the heat exchanger.
[0010] Thereby, it is possible to reduce the risk that condensation will form in the heat
exchanger.
[0011] The radiator of the present invention further comprises a second piping and a bypass
piping. In the second piping, water flows from the heat exchanger side to the heat
source unit side. The bypass piping diverts the water from the first piping to the
second piping without passing the water through the heat exchanger. In addition, if
the flow volume adjusting mechanism assumes the blocked state, then the water flows
from the first piping to the second piping via the bypass piping. Consequently, if
the temperature of the heat exchanger is lower than the dew point temperature of the
air inside the indoor space, then it is possible to divert the cold water flowing
through the first piping to the second piping via the bypass piping.
[0012] Thereby, if the temperature of the heat exchanger is lower than the dew point temperature
of the air inside the indoor space, then it is possible to reduce the risk that the
cold water will flow into the heat exchanger.
[0013] The radiator according to a further aspect of the present invention is the radiator
according to the present invention and further comprises an indoor temperature detection
unit, which is capable of detecting the temperature of the air inside the indoor space.
In addition, the control unit calculates the dew point temperature of the air inside
the indoor space based on the temperature of the air that is detected by the indoor
temperature detection unit. Consequently, the dew point temperature of the air inside
the indoor space can be calculated based on the temperature of the air inside the
indoor space.
[0014] The radiator according to a further aspect of the present invention is the radiator
according to any one aspect of the present invention and further comprises a setting
unit, by which a user can set whether the control unit performs the first cooling
control during the cooling. Consequently, the user can set whether to perform the
first cooling control during cooling.
[0015] Thereby, the indoor space can be cooled in accordance with the needs of the user.
<Advantageous Effects of Invention>
[0016] With the radiator according to the present invention, it is possible to reduce the
risk that condensation will form in the heat exchanger, and if the temperature of
the heat exchanger is lower than the dew point temperature of the air inside the indoor
space, then it is possible to reduce the risk that the cold water will flow into the
heat exchanger.
[0017] In the radiator according to a further aspect of the present invention, the dew point
temperature of the air inside the indoor space can be calculated based on the temperature
of the air inside the indoor space.
[0018] In the radiator according to a further aspect of the present invention, the indoor
space can be cooled in accordance with the needs of the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
FIG. 1 is a schematic drawing of an air conditioning system that comprises radiators according
to an embodiment of the present invention.
FIG. 2 is an external oblique view of one of the radiators according to the embodiment of
the present invention.
FIG. 3 is a control block diagram of a control unit provided by the radiator.
FIG. 4 is a drawing that shows the relationship between the state of a three-way valve and
a prescribed range.
FIG. 5 is a flow chart that depicts a control operation of a heat exchanger temperature
determination unit.
FIG. 6 is a schematic drawing of a heat exchanger and radiator pipings that constitute the
radiator according to a modified example (A).
DESCRIPTION OF EMBODIMENTS
[0020] The text below explains an air conditioning system 1 that comprises radiators
50, 50 according to an embodiment of the present invention.
<Configuration of the Air Conditioning System>
[0021] As shown in
FIG. 1, the air conditioning system
1 comprises a heat source unit
10, a circulation pump
11, a first header
12, a second header
13, and a plurality of (in the present embodiment, two) radiators
50, 50. In addition, a water circulation circuit is configured by connecting the heat source
unit
10, the circulation pump
11, the first header
12, the second header
13, and the radiators
50,
50 with pipings.
[0022] The heat source unit
10 produces cold water or hot water by exchanging heat between water and a refrigerant
or the like. Furthermore, in the present embodiment, a setting unit (not shown) provided
by the heat source unit
10 sets the temperature of the cold water or the hot water produced in the heat source
unit
10. Consequently, the heat source unit
10 exchanges heat between the refrigerant and the water such that the temperature of
the water approaches a set temperature. The circulation pump
11 circulates the water inside the water circulation circuit. One of the radiators
50, 50 is installed in and air conditions each of two indoor spaces
50a,
50b. In addition, the two radiators
50,
50 are connected to one another in parallel via the first header
12 and the second header
13. Furthermore, the configuration of the radiators
50,
50 is explained in detail later.
[0023] The water circulation circuit comprises a first inflow side piping
2, a second inflow side piping
3, third inflow side pipings
4, radiator pipings
5, first outflow side pipings
6, and a second outflow side piping
7. The first inflow side piping
2 connects the heat source unit
10 and the circulation pump
11. In addition, the second inflow side piping
3 connects the circulation pump
11 and the first header
12. The third inflow side pipings
4 connect the first header
12 to the radiators
50,
50. The radiator pipings
5 are disposed inside the radiators
50,
50. Furthermore, the radiator pipings
5 are explained later. The first outflow side pipings
6 connect the radiators
50,
50 to the second header
13. The second outflow side piping
7 connects the second header
13 and the heat source unit
10. Based on such a configuration, in the water circulation circuit, the cold water
or the hot water produced in the heat source unit
10 flows by the operation of the circulation pump
11 to the radiators
50,
50 via the first header
12, and the water that flows from the radiators
50,
50 returns to the heat source unit
10 via the second header
13.
<Radiators>
[0024] The radiators
50,
50 are compact indoor units that can be installed on a floor; furthermore, the radiators
50,
50 can cool and heat the indoor spaces
50a,
50b by sucking in the cold and hot water, respectively, produced in the heat source unit
10. Furthermore, the radiator
50 installed in the indoor space
50a and the radiator
50 installed in the indoor space
50b have the same configuration. In addition, although the radiators
50 of the present embodiment are compact indoor units that can be installed on a floor,
the indoor unit is not limited thereto; for example, each of the radiators may be
a wall mounted indoor unit or a ceiling cassette type indoor unit.
[0025] As shown in
FIG 1 and
FIG 2, each of the radiators
50 comprises a casing
51, a heat exchanger
52, a fan
53, a three-way valve
54, an indoor temperature detection unit
55, and a heat exchanger temperature detection unit
56. Furthermore, in the present embodiment, each of the radiators
50 comprises the heat exchanger
52 and the fan
53 but the present invention is not limited thereto; for example, each of the radiators
must comprise a heat exchanger, but does not have to comprise a fan.
[0026] Each of the casings
51 houses the heat exchanger
52, the fan
53, the indoor temperature detection unit
55, the heat exchanger temperature detection unit
56, the three-way valve
54, and the radiator piping
5. Each of the radiator pipings
5 comprises a first piping
5a, a second piping
5b, a third piping
5c, a fourth piping
5d, and a bypass piping
5e. One end part of the first piping
5a is connected to the third inflow side piping
4 via a connection port (not shown), and another end part of the first piping
5a is connected to the three-way valve
54. In addition, one end part of the second piping
5b is connected to the three-way valve
54, and another end part of the second piping
5b is connected to the heat exchanger
52. One end part of the third piping
5c is connected to the heat exchanger
52, and another end part of the third piping
5c is connected to the fourth piping
5d. One end part of the fourth piping
5d is connected to the third piping
5c, and another end part of the fourth piping
5d is connected to the first outflow side piping
6 via a connection port (not shown). One end part of the bypass piping
5e is connected to the three-way valve
54, and another end part of the bypass piping
5e is connected to a connecting part
5f between the third piping
5c and the fourth piping
5d.
[0027] In addition, as shown in
FIG. 2, each of the casings
51 comprises a bottom frame
51a, a front surface grill
51b and a front surface panel
51c. The bottom frame
51a is substantially oblong. The front surface grill
51b is attached to the front side of the bottom frame
51a. In addition, an opening (not shown) is formed in the front surface of the front surface
grill
51b. The front surface panel
51c is attached to the front side of the front surface grill
51b such that it covers the opening formed in the front surface grill
51b.
[0028] In addition, a first blow out port
51ba is formed in an upper part of the front surface grill
51b. A second blow out port
51bb is formed in a lower part of the front surface grill
51b. In addition, a flap
51d is disposed in the vicinity of and is capable of covering the first blow out port
51ba.
[0029] In addition, a first suction port
51ca is formed in an upper part of the front surface panel
51c. A second suction port
51cb is formed in a lower part of the front surface panel
51c. Third suction ports
51ce, 51cd are respectively formed in the left and right side surfaces of the front surface
panel
51c.
[0030] Each of the heat exchangers
52 comprises a heat transfer pipe, which is folded multiple times at both ends in the
longitudinal directions, and a plurality of fins, wherethrough the heat transfer pipe
is inserted. In addition, one end part of the heat transfer pipe is connected to the
second piping
5b, and another end part of the heat transfer pipe is connected to the third piping
5c. Consequently, in each of the heat exchangers
52, by the circulation pump
11 feeding cold water or hot water from the heat source unit
10, heat is exchanged between the indoor air and the cold water or hot water flowing
inside the heat transfer pipe.
[0031] Each of the fans
53 is a turbofan that sucks air in from its front side (i.e., its front surface side)
and blows the air out in the centrifugal directions. The fan
53 is disposed on the rear side (i.e., rear surface side) of a bell mouth (not shown);
furthermore, the fan
53 sucks air in from the first suction port
51ca, the second suction port
51cb, and the third suction port
51cc, 51cd, passes that air through the heat exchanger
52 and the bell mouth, and generates a flow of air that is blown out from the first
blow out port
51ba and the second blow out port
51bb.
[0032] Each of the three-way valves
54 can assume a first state, wherein the first piping
5a and the second piping
5b are connected, and a second state (corresponding to a blocked state), wherein the
first piping
5a and the bypass piping
5e are connected. Consequently, when the three-way valve
54 assumes the first state, a flow of water from the first piping
5a to the second piping
5b is permitted. Accordingly, when the three-way valve
54 assumes the first state, a flow of water from the heat source unit
10 to the heat exchanger
52 is permitted. In addition, when the three-way valve
54 assumes the first state, a flow of water from the first piping
5a to the bypass piping
5e (i.e., a flow of water in the direction of the broken line arrow in
FIG. 1) is completely blocked. Consequently, if the three-way valve
54 assumes the first state, then the water that flows through the third inflow side
piping
4 flows into the heat exchanger
52 via the first piping
5a and the second piping
5b. Furthermore, the water that flows into the heat exchanger
52 flows to the first outflow side piping
6 via the third piping
5c and fourth piping
5d. In addition, if the three-way valve
54 assumes the second state, then the flow of water from the heat source unit
10 to the heat exchanger
52 is completely blocked. Consequently, if the three-way valve
54 assumes the second state, then the flow of water from the first piping
5a to the second piping
5b is completely blocked, and the flow of water from the first piping
5a to the bypass piping
5e (i.e., the flow of water in the direction of the broken line arrow in
FIG. 1) is permitted. Accordingly, if the three-way valve
54 assumes the second state, then the water that flows through the third inflow side
piping
4 flows from the first piping
5a to the fourth piping
5d via the bypass piping
5e and subsequently flows to the first outflow side piping
6. Thereby, if the three-way valve
54 assumes the second state, then the water that flows from the heat source unit
10 flows back to the heat source unit
10 without flowing into the heat exchanger
52.
[0033] The indoor temperature detection units
55 detect the temperature of the indoor spaces
50a,
50b, wherein the radiators
50 are installed. In addition, each of the indoor temperature detection units
55 is disposed inside the corresponding casing
51 in the vicinity of the third suction port
51cc. Furthermore, information about the indoor temperature detected by the indoor temperature
detection unit
55 is transmitted to a control unit
60 (discussed below) as needed.
[0034] Each of the heat exchanger temperature detection units
56 detects the temperature of the corresponding heat exchanger
52. In addition, the heat exchanger temperature detection unit
56 is disposed in the vicinity of the corresponding heat exchanger
52. Furthermore, information about the temperature of the heat exchanger
52 detected by the heat exchanger temperature detection unit
56 is transmitted the control unit
60 (discussed below) as needed.
[0035] In addition, each of the radiators
50 comprises one of the control units
60, which controls the corresponding three-way valve
54. The control units
60 are explained below.
<Control Units>
[0036] As shown in
FIG. 3, each of the control units
60 is connected to the three-way valve
54 of the corresponding radiator
50; furthermore, the control units
60 control the three-way valves
54 such that the indoor spaces
50a, 50b are cooled or heated. In addition, as shown in
FIG. 1, each of the radiators
50 comprises one of the control units
60.
[0037] Each of the control units
60 is capable of receiving various instructions transmitted from a user via a wireless
remote controller
80. Furthermore, the various instructions include operation setting instructions, a
set temperature instruction, and an air volume setting instruction. In addition, the
operation setting instructions include a cooling setting instruction to cool the indoor
spaces
50a, 50b and a heating setting instruction to heat the indoor spaces
50a, 50b. In addition, each of the remote controllers
80 comprises: an operation setting unit
81, which transmits the operation setting instructions to the corresponding control
unit
60; a temperature setting unit
82, which transmits the set temperature instruction to the corresponding control unit
60; and an air volume setting unit
83, which transmits the air volume setting instruction to the corresponding control
unit
60. By operating the operation setting unit
81, the temperature setting unit
82, and the air volume setting unit
83, the user can transmit the various instructions to the corresponding control unit
60.
[0038] In addition, each of the control units
60 comprises a cooling operation control unit
61, which controls the corresponding three-way valve
54 when the cooling setting instruction is transmitted via the remote controller
80. When the cooling operation control unit
61 cools the corresponding indoor space of the indoor spaces
50a,
50b, namely, when it causes the corresponding radiator
50 to perform a cooling operation, the cooling operation control unit
61 performs a first cooling control and a second cooling control. When performing the
first cooling control, the cooling operation control unit
61 switches the three-way valve
54 in either of the state selected from the first state and the second state so that
a heat exchanger temperature detected by the heat exchanger temperature detection
unit
56 does not fall below the dew point temperature of the air inside the corresponding
indoor space of the indoor spaces
50a,
50b. In addition, when performing the second cooling control, the cooling operation control
unit
61 switches the three-way valve
54 to the first state. Furthermore, when performing the second cooling control, the
cooling operation control unit
61 does not switch the three-way valve
54 from the first state to the second state. Consequently, if the second cooling control
is performed during cooling of the corresponding indoor space of the indoor spaces
50a, 50b, then the three-way valve
54 is not switched to the second state even if the heat exchanger temperature detected
by the heat exchanger temperature detection unit
56 is lower than the dew point temperature of the air inside the corresponding indoor
space of the indoor spaces
50a, 50b.
[0039] In addition, each of the cooling operation control units
61 comprises a jumper
69, a determination unit
63, and an operation unit
64.
[0040] The jumper
69 is used to set whether the first cooling control or the second cooling control is
performed during cooling of the corresponding indoor space of the indoor spaces
50a, 50b. If the jumper
69 is disconnected, then the cooling operation control unit
61 determines that the performance of the first cooling control is permitted. In addition,
if the jumper
69 is not disconnected, then the cooling operation control unit
61 determines that the performance of the second cooling control is permitted. Consequently,
the cooling operation control unit
61 determines whether the first cooling control or the second cooling control is performed
during cooling of the corresponding indoor space of the indoor spaces
50a, 50b based on the disconnection state of the jumper
69.
[0041] Each of the determination unit
63 comprises a capacity supply determination unit 65, a dew point temperature calculating
unit
62, and a heat exchanger temperature determination unit
66.
[0042] The capacity supply determination unit
65 determines whether there is a need to supply capacity to the corresponding heat exchanger
52. Specifically, the capacity supply determination unit
65 determines whether there is a need to flow cold water or hot water to the heat exchanger
52 by comparing a set temperature value, which is obtained from set temperature information
based on a set temperature instruction transmitted from the corresponding remote controller
80, and an indoor temperature value, which is obtained from the indoor temperature information
transmitted from the corresponding indoor temperature detection unit
55. More specifically, if the set temperature value and the indoor temperature value
differ by a first prescribed temperature value (e.g., a value corresponding to 1°C
as a temperature) or greater, then it is determined that there is a need to supply
capacity. In addition, if the difference between the set temperature value and the
indoor temperature value is less than the first prescribed temperature value, then
the capacity supply determination unit
65 determines that there is no need to supply capacity. Furthermore, if the capacity
supply determination unit
65 determines that there is a need to supply capacity, then the capacity supply determination
unit
65 transmits capacity supply needed information (hereinbelow, called demand present
information) to the operation unit
64. In addition, if the capacity supply determination unit
65 determines that there is no need to supply capacity, then the capacity supply determination
unit
65 transmits capacity supply unneeded information (hereinbelow, called demand absent
information) to the operation unit
64.
[0043] If the first cooling control is performed, then the dew point temperature calculating
unit
62 calculates a threshold value
X by estimating the dew point temperature of the air inside the corresponding indoor
space of the indoor spaces
50a, 50b. Specifically, the dew point temperature calculating unit
62 calculates the threshold value
X based on an environmental condition of the geographical area in which the radiator
50 is installed and the indoor temperature value obtained from the indoor temperature
information transmitted from the indoor temperature detection unit
55. Furthermore, the dew point temperature calculating unit
62 calculates the threshold value Xbased on the equation below.
[0044] Threshold value
X = prescribed value
A × indoor temperature value + correction value
B
[0045] Furthermore, a prescribed value
A is a coefficient that varies with the environmental condition of the geographical
area. In addition, a correction value
B is determined in accordance with the environmental condition of the geographical
area in which the radiator
50 is installed. The user can switch between the correction value
B being present or absent by operating a slide switch or the like. For example, if
the correction value
B is set to "none" and the indoor temperature in the geographical area with a relative
humidity of 60% is 20°C, then the dew point temperature calculating unit
62 sets the prescribed value
A to 0.6 and the indoor temperature value to 20, and then calculates the threshold
value
X.
[0046] If the first cooling control is performed, then the heat exchanger temperature determination
unit
66 performs a heat exchanger temperature determination by determining whether a heat
exchanger temperature value, which is obtained from heat exchanger temperature information
transmitted from the heat exchanger temperature detection unit
56, is within a prescribed range. Furthermore, herein, the prescribed range is a region
of values greater than or equal to the threshold value
X, which is calculated by the dew point temperature calculating unit
62. If the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is within the prescribed range,
namely, if it determines that the temperature of the heat exchanger
52 is greater than or equal to the dew point temperature of the air inside the corresponding
indoor space of the indoor spaces
50a, 50b, then the heat exchanger temperature determination unit
66 determines that it is possible to further supply cold water to the heat exchanger
52 and therefore transmits supply possible information to the operation unit
64. In addition, if the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is not within the prescribed
range, namely, if it determines that the temperature of the heat exchanger
52 is lower than the dew point temperature of the air inside the corresponding indoor
space of the indoor spaces
50a,
50b, then the heat exchanger temperature determination unit
66 determines that it is not possible to further supply the cold water to the heat exchanger
52 and therefore transmits supply not possible information to the operation unit
64.
[0047] In addition, as shows in
FIG. 4, the prescribed range includes a first range and a second range. The first range
is a region of values from a value
X+C, which is a value that is greater than threshold value
X by a prescribed value
C, to the threshold value
X. In addition, the second range is a region of values that is greater than or equal
to the value
X+
C, which is greater than the threshold value
X by the prescribed value
C.
[0048] If the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is within the second range,
then the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is within the prescribed range.
In addition, if the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is within the first range, then,
in accordance with the state of the corresponding three-way valve
54, the heat exchanger temperature determination unit
66 determines whether the heat exchanger temperature value is within the prescribed
range. For example, if the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is within the first range and
if the supply possible information was transmitted to the operation unit
64 in the previous heat exchanger temperature determination, then the heat exchanger
temperature determination unit
66 determines that the heat exchanger temperature value is within the prescribed range.
In addition, if the heat exchanger temperature determination unit
66 determines that the heat exchanger temperature value is within the first range and
if the supply not possible information was transmitted to the operation unit
64 in the previous heat exchanger temperature determination, then the heat exchanger
temperature determination unit
66 determines that the heat exchanger temperature value is not within the prescribed
range. Thus, imparting so-called hysteresis characteristics to the operation of switching
the state of the three-way valve
54 prevents the phenomenon of hunting, wherein the state of the three-way valve
54 is switched in micro steps when the heat exchanger temperature value is in the vicinity
of the threshold value
X.
[0049] The operation unit
64 switches the state of the three-way valve
54 by transmitting an energize signal or a de-energize signal to the three-way valve
54. Specifically, the operation unit
64 switches the three-way valve
54 to the first state by transmitting the energize signal to the three-way valve
54. In addition, the operation unit
64 switches the three-way valve
54 to the second state by transmitting the de-energize signal to the three-way valve
54.
[0050] In addition, if the demand present information is transmitted from the capacity supply
determination unit
65, then the operation unit
64 transmits the energize signal to the three-way valve
54. In addition, if the demand absent information is transmitted from the capacity supply
determination unit
65, then the operation unit
64 transmits the de-energize signal to the three-way valve
54. Furthermore, if the supply possible information is transmitted from the heat exchanger
temperature determination unit
66 after the demand present information has been transmitted from the capacity supply
determination unit
65, then the operation unit
64 transmits the energize signal to the three-way valve
54. In addition, if the supply not possible information is transmitted from the heat
exchanger temperature determination unit
66 after the demand present information has been transmitted from the capacity supply
determination unit
65, then the operation unit
64 transmits the de-energize signal to the three-way valve
54. Furthermore, if the supply not possible information is transmitted from the heat
exchanger temperature determination unit
66, then the operation unit
64 ignores the demand present information transmitted from the capacity supply determination
unit
65 until a first prescribed time has elapsed since the supply not possible information
was transmitted. Consequently, if the supply not possible information is transmitted
from the heat exchanger temperature determination unit
66, then the operation unit
64 does not transmit the energize signal to the three-way valve
54 until the first prescribed time has elapsed since the supply not possible information
was transmitted. Thereby, if the first cooling control is performed during cooling
of one of the indoor spaces
50a, 50b and the corresponding capacity supply determination unit
65 determines that there is a need to supply capacity and the heat exchanger temperature
determination unit
66 determines that the heat exchanger temperature value is within the prescribed range,
then the three-way valve
54 assumes the first state. In addition, if the first cooling control is performed during
cooling of one of the indoor spaces
50a, 50b and if the corresponding capacity supply determination unit
65 determines that there is no need to supply capacity or the capacity supply determination
unit
65 determines that there is a need to supply capacity and the heat exchanger temperature
determination unit
66 determines that the heat exchanger temperature value is not within the prescribed
range, then the three-way valve
54 assumes the second state. In addition, if the second cooling control is performed
during cooling of one of the indoor spaces
50a, 50b and the corresponding capacity supply determination unit
65 determines that there is a need to supply capacity because the heat exchanger temperature
determination unit
66 does not perform the heat exchanger temperature determination, then the three-way
valve
54 always assumes the first state. In addition, if the second cooling control is performed
during cooling of one of the indoor spaces
50a, 50b and the corresponding capacity supply determination unit
65 determines that there is no need to supply capacity because the heat exchanger temperature
determination unit
66 does not perform the heat exchanger temperature determination, then, and only then,
does the three-way valve
54 assume the second state.
[0051] Furthermore, in the present embodiment, the three-way valve
54 and the fan
53 are controlled independently.
<Operation of Controlling the Three-way Valve During the First Cooling Control>
[0052] Next, the operation of controlling the three-way valve
54 when one of the cooling operation control units
61 performs the first cooling control will be explained, referencing
FIG. 5. Furthermore,
FIG. 5 is a flow chart that depicts the flow of the heat exchanger temperature determination,
which is performed by the heat exchanger temperature determination unit
66. Furthermore, the explanation herein addresses the case wherein the three-way valve
54 is in the second state and the flow of water from the first piping
5a to the second piping
5b is blocked.
[0053] If the capacity supply determination unit
65 determines that there is a need to supply capacity, then it transmits demand present
information to the operation unit
64 so that cold water flows into the heat exchanger
52 (i.e., in a step
S1). In response to the transmission of the demand present information from the capacity
supply determination unit
65, the operation unit
64 transmits the energize signal to the three-way valve
54 so that the three-way valve
54 transitions to the first state. Thereby, the three-way valve
54 switches from the second state to the first state and cold water flows into the heat
exchanger
52.
[0054] In addition, the heat exchanger temperature determination unit
66 performs the heat exchanger temperature determination after a second prescribed time
has elapsed since the three-way valve
54 switched from the second state to the first state (e.g., after the time it takes
for the temperature of the heat exchanger
52 and the temperature of the cold water flowing through the heat exchanger
52 to equalize) (i.e., in a step
S2). Furthermore, if the heat exchanger temperature determination unit
66 determines that the supply of cold water to the heat exchanger
52 is possible, then it transmits the supply possible information to the operation unit
64 (i.e., in a step
S3 and a step
S4). If the supply possible information is transmitted from the heat exchanger temperature
determination unit
66, then the operation unit
64 transmits the energize signal to the three-way valve
54 so that the three-way valve
54 maintains the first state as is. Thereby, the three-way valve
54 maintains the first state without switching to the second state. Subsequently, if
the capacity supply determination unit
65 determines that there is no need to supply capacity, then it transmits the demand
absent information to the operation unit
64 (i.e., in a step
S5). If the demand absent information is transmitted from the capacity supply determination
unit
65, then the operation unit
64 transmits the de-energize signal to the three-way valve
54 so that the three-way valve
54 switches from the first state to the second state. Thereby, the three-way valve
54 switches from the first state to the second state.
[0055] In addition, if the heat exchanger temperature determination unit
66 transmits the supply possible information to the operation unit
64 and the capacity supply determination unit
65 does not subsequently determine that there is no need to supply capacity, namely,
if the demand absent information is not transmitted from the capacity supply determination
unit
65 to the operation unit
64, then the heat exchanger temperature determination unit
66 once again performs the heat exchanger temperature determination (i.e., in a step
S6). Furthermore, if the heat exchanger temperature determination unit
66 determines once again in the heat exchanger temperature determination of the step
S6 that the supply of cold water to the heat exchanger
52 is possible (i.e., in a step
S7), then the method returns to the step
S4 and the heat exchanger temperature determination unit
66 transmits the supply possible information to the operation unit
64. If the supply possible information is transmitted from the heat exchanger temperature
determination unit
66, then the operation unit
64 transmits the energize signal to the three-way valve
54 so that the three-way valve
54 maintains the first state as is. Thereby, the three-way valve
54 maintains the first state without switching to the second state. In addition, if
the heat exchanger temperature determination unit
66 determines in the heat exchanger temperature determination (i.e., in the step
S6) performed after the supply possible information has been transmitted to the operation
unit
64 that the supply of cold water to the heat exchanger
52 is not possible, then the heat exchanger temperature determination unit
66 transmits the supply not possible information to the operation unit
64 so that the water does not further flow into the heat exchanger
52 (i.e., in a step
S8). Furthermore, the heat exchanger temperature determination of the step
S6 is performed repetitively until either the capacity supply determination unit
65 determines that there is no need to supply capacity or it is determined in the heat
exchanger temperature determination of the step
S6 that the supply of cold water to the heat exchanger
52 is not possible (i.e., in the step
S5 and the step
S7).
[0056] In addition, if the heat exchanger temperature determination unit
66 determines in the step
S3 that the supply of cold water to the heat exchanger
52 is not possible, then the heat exchanger temperature determination unit
66 transmits the supply not possible information to the operation unit
64 so that the water does not flow into the heat exchanger
52 (i.e., in the step
S8). If the supply not possible information is transmitted from the heat exchanger temperature
determination unit
66, then the operation unit
64 transmits the de-energize signal to the three-way valve
54 so that the three-way valve
54 switches to the second state. Thereby, the three-way valve
54 switches from the first state to the second state.
[0057] Furthermore, until the first prescribed time has elapsed since the transmission of
the supply not possible information from the heat exchanger temperature determination
unit
66, the operation unit
64 ignores the demand present information transmitted from the capacity supply determination
unit
65. Consequently, until the first prescribed time has elapsed since the transmission
of the supply not possible information from the heat exchanger temperature determination
unit
66, the operation unit
64 does not transmit the energize signal to the three-way valve
54. Consequently, even if the capacity supply determination unit
65 determines that there is a need to supply capacity, the three-way valve
54 maintains the second state, to which it has switched. In addition, if the demand
absent information is transmitted from the capacity supply determination unit
65 before the first prescribed time has elapsed since the transmission of the supply
not possible information from the heat exchanger temperature deterniination unit
66, then the operation unit
64 transmits the de-energize signal to the three-way valve
54 (i.e., in a step
S9). In this case, too, the three-way valve
54 maintains the second state, to which it has switched.
[0058] Furthermore, if the demand absent information is not transmitted from the capacity
supply determination unit
65 by the time the first prescribed time has elapsed since the transmission of the supply
not possible information from the heat exchanger temperature determination unit
66, namely, if the demand present information is transmitted from the capacity supply
determination unit
65 after the first prescribed time has elapsed since the transmission of the supply
not possible information from the heat exchanger temperature determination unit
66, then the operation unit
64 transmits the energize signal to the three-way valve
54 (i.e., in a step
S10). Thereby, the three-way valve
54 switches from the second state to the first state. Furthermore, after the second
prescribed time has elapsed since the three-way valve
54 switched from the second state to the first state, the heat exchanger temperature
determination unit
66 once again performs the heat exchanger temperature determination (i.e., in a step
S11). Furthermore, if the heat exchanger temperature determination unit
66 determines that the supply of cold water to the heat exchanger
52 is possible in the heat exchanger temperature determination of the step
S11, then the method returns to the step
S4 and the water temperature determination unit
66 transmits the supply possible information to the operation unit
64 (i.e., in a step
S12). If the supply possible information is transmitted from the heat exchanger temperature
determination unit
66, then the operation unit
64 transmits the energize signal to the three-way valve
54 so that the three-way valve
54 maintains the first state as is. Thereby, the three-way valve
54 maintains the first state without switching to the second state.
[0059] In addition, if the heat exchanger temperature determination unit
66 determines in the heat exchanger temperature determination of the step
S11 that the supply of cold water to the heat exchanger
52 is not possible, then the method returns to the step
S8 and the heat exchanger temperature determination unit
66 transmits the supply not possible information to the operation unit
64 (i.e., the step
S12). If the supply not possible information is transmitted from the heat exchanger temperature
determination unit
66, then the operation unit
64 transmits the de-energize signal to the three-way valve
54 so that the three-way valve
54 switches from the first state to the second state. Thereby, the three-way valve
54 switches from the first state to the second state.
[0060] Thus, the heat exchanger temperature determination unit
66 repetitively performs the heat exchanger temperature determination of the step
S6 or the step
S11 every time the prescribed time elapses until the capacity supply determination unit
65 determines that there is no need to supply capacity.
<Features>
[0061]
- (1) In the abovementioned embodiment, the cooling operation control unit 61 performs the first cooling control, wherein the three-way valve 54 is switched from the first state to the second state so that the heat exchanger temperature
value does not fall below the dew point temperature of the air in the corresponding
indoor space of the indoor spaces 50a, 50b. Consequently, if the cooling operation control unit 61 performs the first cooling control, then it is possible to reduce the risk that the
temperature of the heat exchanger 52 during cooling will fall below the dew point temperature of the air in the corresponding
indoor space of the indoor spaces 50a, 50b.
Thereby, it is possible to reduce the risk that condensation will form in the heat
exchanger 52.
In addition, if the cooling operation control unit 61 performs the first cooling control, then it is possible to implement a cooling operation
(i.e., a sensible cooling), wherein by controlling the three-way valve 54 no more capacity than is needed is supplied and wherein the air in the corresponding
indoor space of the indoor spaces 50a, 50b tends not to become dehumidified even during cooling. Thereby, comfort can be improved
because the temperature of the air in the corresponding indoor space of the indoor
spaces 50a, 50b can be reduced without excessively ridding the air of moisture.
Furthermore, if condensation is not formed in the heat exchanger 52 as a result of the performance of the first cooling control during cooling, then
there is no need to provide a drain piping for discharging the formed condensation
to the outdoor space. Accordingly, if the first cooling control alone is performed
during cooling, then the manufacturability of the radiator 50 can be improved because there is no need to provide the drain piping.
- (2) In the abovementioned embodiment, if, as a result of the performance of the first
cooling control, the heat exchanger temperature determination unit 66 determines that the heat exchanger temperature value is not within the prescribed
range, then the three-way valve 54 is switched to the second state. Here, the prescribed range is a region of values
greater than or equal to the threshold value X, which is calculated by the dew point temperature calculating unit 62, namely, values greater than or equal to an estimated value of the dew point temperature
of the air in the corresponding indoor space of the indoor spaces 50a, 50b. Consequently, if as a result of the performance of the first cooling control, the
heat exchanger temperature determination unit 66 determines that the heat exchanger temperature value is not within the prescribed
range, then the flow of the cold water into the heat exchanger 52 is blocked, which makes it possible to ensure that the temperature of the heat exchanger
52 does not further decrease.
Thereby, it is possible to reduce the risk that the temperature of the heat exchanger
52 will fall below the dew point temperature of the air in the corresponding indoor
space of the indoor spaces 50a, 50b.
- (3) In the abovementioned embodiment, if the three-way valve 54 assumes the second state, then the flow of water from the first piping 5a to the second piping 5b is completely blocked and the flow of the water from the first piping 5a to the bypass piping 5e is permitted. Consequently, it is possible to return the cold water flowing through
the first piping 5a to the heat source unit 10 side via the bypass piping 5e.
Thereby, if the temperature of the heat exchanger 52 is lower than the dew point temperature of the air inside the corresponding indoor
space of the indoor spaces 50a, 50b, then it is possible to return the cold water to the heat source unit 10 side without the cold water flowing to the heat exchanger 52.
- (4) In the abovementioned embodiment, the dew point temperature calculating unit 62 calculates the threshold value X, which is obtained by estimating the dew point temperature of the air inside the
corresponding indoor space of the indoor spaces 50a, 50b based on the environmental condition of the geographical region in which the radiator
50 is installed and on the indoor temperature value obtained from the indoor temperature
information transmitted from the indoor temperature detection unit 55. Consequently, it is possible to estimate the dew point temperature of the air inside
the corresponding indoor space of the indoor spaces 50a, 50b even if a humidity sensor, which detects the humidity of the air therein, is not
provided.
- (5) In the abovementioned embodiment, the cooling operation control unit 61 determines whether to perform the first cooling control or the second cooling control
during cooling based on the disconnection state of the jumper 69. Consequently, the user can set whether the cooling operation control unit 61 performs the first cooling control or the second cooling control during cooling of
the corresponding indoor space of the indoor spaces 50a, 50b.
[0062] Thereby, it is possible to cool the corresponding indoor space of the indoor spaces
50a, 50b in accordance with the needs of the user.
<Modified Examples>
[0063]
- (A) In the abovementioned embodiment, the three-way valve 54 is adopted to block the flow of the cold water into the heat exchanger 52.
A two-way valve (i.e., a solenoid valve), which is configured such that it can only
open or close, may be adopted as long as the flow of the cold water into the heat
exchanger 52 can be blocked.
In addition, if a two-way valve 154 is adopted instead of the three-way valve 54 in the abovementioned embodiment, as shown in FIG. 6, then a radiator piping 105 may comprise a first piping 105a, which is connected to the third inflow side piping 4, a second piping 105b, which connects the two-way valve 154 and the heat exchanger 52, and a third piping 105c, which connects the heat exchanger 52 and the first outflow side piping 6. Even in such a configuration, the flow of water from the heat source unit side to
the heat exchanger 52 side can be blocked by setting the two-way valve 154 to a closed state, and the flow of the water from the heat source unit side to the
heat exchanger 52 side can be permitted by setting the two-way valve 154 to an open state. Accordingly, the cooling operation control unit can perform the
first cooling control by setting the two-way valve 154 to the open state or the closed state so that the temperature of the heat exchanger
52 is greater than or equal to the dew point temperature of the air inside the corresponding
indoor space of the indoor spaces.
In addition, instead of a solenoid valve, a motor operated valve configured such that
it is capable of flow volume adjustment may be provided. For example, if the motor
operated valve is adopted instead of the three-way valve 54, then the flow volume of the cold water flowing through the heat exchanger 52 may be adjusted by adjusting the opening degree of the motor operated valve so that
the temperature of the heat exchanger 52 reaches a temperature that is greater than or equal to the dew point temperature.
- (B) In the abovementioned embodiment, the dew point temperature is estimated based on
the indoor temperature value. However, instead, the radiator may comprise an indoor
humidity detection unit that is capable of detecting the relative humidity of the
corresponding indoor space of the indoor spaces 50a, 50b. In such a case, a dew point temperature calculating unit may calculate the threshold
value based on the indoor humidity value, which is obtained from the indoor humidity
information detected by the indoor humidity detection unit, and the indoor temperature
value.
- (C) In the abovementioned embodiment, by the performance of the first cooling control,
the state of the three-way valve 54 is switched so that the heat exchanger temperature during cooling does not fall below
the dew point temperature.
[0064] Additionally, if the determination unit further performs a water temperature determination,
which determines whether the temperature of the water flowing into the heat exchanger
52 is within the prescribed temperature range (e.g., a temperature range that does not
lie outside of the working range of the heat exchanger
52), and it is thereby determined that the temperature of the water flowing into the
heat exchanger
52 is not within the prescribed temperature range, namely, if it is determined that
the temperature of the water flowing into the heat exchanger
52 falls outside of the working range of the heat exchanger
52 (e.g., a temperature so low the water freezes or so high the water adversely affects
the heat resistance of the heat exchanger
52), then control may be performed that switches the three-way valve
54 to the second state so that the water does not flow into the heat exchanger
52. Thus, if the state of the three-way valve
54 is switched in accordance with the temperature of the water flowing into the heat
exchanger
52, then it is possible to reduce the risk that water of a temperature outside of the
working range of the heat exchanger
52 will flow into the heat exchanger
52. Accordingly, if, for example, the water temperature determination is performed together
with the heat exchanger temperature determination in the first cooling control and
the dew point temperature of the corresponding indoor space of the indoor spaces
50a, 50b is lower than the working range of the heat exchanger
52, then the three-way valve
54 is switched to the second state even if the heat exchanger temperature is higher
than the dew point temperature. Consequently, during the performance of the first
cooling control, it is possible to reduce the risk that water of a temperature outside
of the working range of the heat exchanger
52 will flow into the heat exchanger
52, which makes it possible to reduce the risk that the heat exchanger
52 will break.
INDUSTRIAL APPLICABILITY
[0065] The present invention can reduce the risk that condensation will be formed in the
heat exchanger, which makes it effective to adapt the present invention to a radiator
that cools an indoor space by sucking in cold water.
REFERENCE SIGNS LIST
[0066]
- 5a
- First piping
- 5d
- Fourth piping (second piping)
- 5e
- Bypass piping
- 10
- Heat source unit
- 50
- Radiator
- 52
- Heat exchanger
- 54
- Three-way valve (flow volume adjusting mechanism)
- 55
- Indoor temperature detection unit
- 56
- Heat exchanger temperature detection unit
- 60
- Control unit
- 69
- Jumper (setting unit)
- 50a, 50b
- Indoor spaces
CITATION LIST
PATENT LITERATURE
Patent Document 1
[0067] Japanese Unexamined Patent Application Publication No.
2002-98344