EP2363659A1

EP2363659A1 - Radiator

Info

Publication number: EP2363659A1
Application number: EP10784940A
Authority: EP
Inventors: Akinori Nakai; Katsuki MOCHIZUKI
Original assignee: Daikin Europe NV; Daikin Industries Ltd
Current assignee: Daikin Europe NV; Daikin Industries Ltd
Priority date: 2010-01-08
Filing date: 2010-01-08
Publication date: 2011-09-07
Anticipated expiration: 2030-01-08
Also published as: EP2363659B1; EP2363659A4; WO2011083517A1

Abstract

A radiator (50) is a radiator that cools an indoor space (50a, 50b) by sucking in cold water from a heat source unit (10) and comprises a heat exchanger (52), a first piping (5a), a three-way valve (54), a heat exchanger temperature detection unit (56), and a control unit (60). In the first piping (5a), the cold water flows from the heat source unit (10) side to the heat exchanger (52) side. The three-way valve (54) adjusts the flow volume of the cold water flowing through the heat exchanger (52). The heat exchanger temperature detection unit (56) is capable of detecting the temperature of the heat exchanger (52). The control unit (60) performs a first cooling control that controls the three-way valve (54) so that the temperature of the heat exchanger (52) detected by the heat exchanger temperature detection unit (56) is greater than or equal to the dew point temperature of air inside the indoor space (50a, 50b).

Description

TECHNICAL FIELD

The present invention relates to a radiator that cools by sucking in cold water from a heat source unit.

BACKGROUND ART

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).

SUMMARY OF THE INVENTION

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.
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.

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.
In the radiator according to the first aspect of 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.
Thereby, it is possible to reduce the risk that condensation will form in the heat exchanger.
The radiator according to a second aspect of the present invention is the radiator according to the first aspect of the present invention 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.
Thereby, it is possible to reduce the risk that condensation will form in the heat exchanger.
The radiator according to a third aspect of the present invention is the radiator according to the second aspect of the present invention and 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.
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.
The radiator according to a fourth aspect of the present invention is the radiator according to any one aspect of the first through third aspects of 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.
The radiator according to a fifth aspect of the present invention is the radiator according to any one aspect of the first through fourth aspects 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.
Thereby, the indoor space can be cooled in accordance with the needs of the user.

With the radiator according to the first aspect of the present invention, it is possible to reduce the risk that condensation will form in the heat exchanger.
With the radiator according to the second aspect of the present invention, it is possible to reduce the risk that condensation will form in the heat exchanger.
With the radiator according to the third aspect of the present invention, 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.
In the radiator according to the fourth 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.
In the radiator according to the fifth aspect of the present invention, the indoor space can be cooled in accordance with the needs of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

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

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>

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.
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.
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>

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.
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.
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.
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.
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.
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 51cc, 51cd are respectively formed in the left and right side surfaces of the front surface panel 51c.
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.
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.
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.
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.
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.
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>

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.
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.
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.
In addition, each of the cooling operation control units 61 comprises a jumper 69, a determination unit 63, and an operation unit 64.
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.
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.
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.
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 X based on the equation below. $Threshold value X = prescribed value A \times indoor temperature value + correction value B$
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.
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.
In addition, as shown 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.
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.
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.
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.
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>

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.
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.
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.
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).
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.
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 determination 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.
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.
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.
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>

(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.
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>

(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.
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

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

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

Japanese Unexamined Patent Application Publication No. 2002-98344

Claims

A radiator (50) that cools an indoor space (50a, 50b) by sucking in cold water from a heat source unit (10), comprising:
a heat exchanger (52);

a first piping (5a), wherethrough the cold water flows from the heat source unit side to the heat exchanger side;

a flow volume adjusting mechanism (54), which adjusts the flow volume of the cold water flowing through the heat exchanger;

a heat exchanger temperature detection unit (56), which is capable of detecting the temperature of the heat exchanger; and

a control unit (60), which 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.
The radiator according to claim 1, 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; and
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.
The radiator according to claim 2, further comprising:
a second piping (5d), wherethrough water flows from the heat exchanger side to the heat source unit side; and

a bypass piping (5e), which diverts the water from the first piping to the second piping

without passing the water through the heat exchanger;
wherein,

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.
The radiator according to any one claim of claim 1 through claim 3, further comprising:
an indoor temperature detection unit (55), which is capable of detecting the

temperature of the air inside the indoor space;
wherein,

the control unit calculates the dew point temperature of the air inside the indoor space based on the temperature of the air inside the indoor space that is detected by the indoor temperature detection unit.
The radiator according to any one claim of claim 1 through claim 4, further comprising:
a setting unit (69), by which a user can set whether the control unit performs the first cooling control during the cooling.