Radiation type cooling apparatus

Abstract

To provide a radiation type cooling apparatus capable of stopping dew condensation after cooling operation stops.SOLUTION: A radiation type cooling apparatus has dew condensation estimation means 19a which estimates a level of a dew condensation risk on a radiation panel 30 after cooling operation stops, and after a command to stop the cooling operation is sent from a remote controller 40 as command means, a control part 19 performs predetermined dew condensation preventing operation to prevent dew condensation on the radiation panel 30 as a radiation terminal according to the level of the dew condensation risk estimated by the dew condensation estimation means 19a. The predetermined dew condensation preventing operation is thus performed according to the level of the dew condensation risk on the radiation panel 30 at the stop of cooling operation, and the dew condensation on the radiation panel 30 at the stop of the cooling operation is prevented, so that mold growth due to dew condensation can be prevented to improve the product quality.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a radiant cooling device that conditions an air-conditioned space by radiant cooling. [Background technology]

[0002] Conventionally, in this type of system, a radiant panel is installed in the air-conditioned space as a radiant terminal capable of radiant cooling, and in systems where cooling operation can be performed using the radiant panel, the surface temperature of the radiant panel is controlled to be always higher than the dew point temperature of the air-conditioned space, thereby preventing condensation from forming on the surface of the radiant panel (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-78332 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, this conventional technology does not disclose any control after the cooling operation by the radiant panel has stopped. If low-temperature circulating fluid remains in the radiant panel after the cooling operation by the radiant panel has stopped, condensation will occur on the radiant panel, increasing the possibility of mold growth, so there is room for improvement. [Means for solving the problem]

[0005] In order to solve the above problem, in claim 1 of the present invention, there is provided a heat pump type heat source machine including a compressor that compresses a refrigerant, a load side heat exchanger that exchanges heat between a circulating liquid and the refrigerant, a pressure reducing means, and a heat source side heat exchanger; a load-side circulation circuit in which the load-side heat exchanger, a load-side circulation pump for circulating the circulating fluid, and a radiation terminal through which the circulating fluid flows by driving the load-side circulation pump are connected in a ring shape by piping; an instruction means for issuing an instruction to start and stop a cooling operation in which the circulating fluid cooled by driving the heat pump type heat source machine is circulated in the radiation terminal to cool the surroundings; a control unit that drives the heat pump type heat source machine and the load side circulation pump when the instruction means issues an instruction to start the cooling operation, a condensation estimation means for estimating a level of a condensation risk at the radiation terminal after the cooling operation is stopped, After the instruction means issues an instruction to stop the air conditioning operation, the control unit performs a predetermined condensation prevention operation to prevent condensation from occurring on the radiation terminal, depending on the level of the condensation risk estimated by the condensation estimation means.

[0006] In claim 2, the predetermined dew condensation prevention operation is a quick-drying operation in which the heat pump type heat source machine is driven to heat the circulating fluid in the load-side heat exchanger for a predetermined time and the heated circulating fluid is sent to the radiation terminal; a normal drying operation in which the load-side circulation pump is driven at least until the circulating liquid in the radiation terminal flows out; When the condensation estimation means estimates that the condensation risk is high, the control unit performs the quick drying operation, When the condensation estimating means estimates that the risk of condensation is low, the control unit performs the normal drying operation.

[0007] In addition, in claim 3, an outside air temperature sensor that detects the outside air temperature, a return temperature sensor for detecting the temperature of the circulating fluid flowing out from the radiation terminal; If the detected value of the outside air temperature sensor when the air conditioning operation is stopped is equal to or higher than a predetermined high temperature value and the detected value of the return temperature sensor is equal to or lower than a predetermined low temperature value, the condensation estimation means estimates that the risk of condensation is high.

[0008] In claim 4, an outside air temperature sensor for detecting the outside air temperature; a return temperature sensor that detects the temperature of the circulating fluid flowing out from the radiation terminal; and humidity detection means for detecting humidity in an air-conditioned space in which the radiation terminal is installed, If the detected value of the outside air temperature sensor when the air conditioning operation is stopped is equal to or higher than a predetermined high temperature value, the detected value of the return temperature sensor is equal to or lower than a predetermined low temperature value, and the detected value of the humidity detection means when the air conditioning operation is stopped is equal to or higher than a predetermined high humidity value, the condensation estimation means estimates that the risk of condensation is high.

[0009] In addition, claim 5 is characterized in that the radiation terminal is installed as a predetermined member that constitutes the air-conditioned space. [Effects of the Invention]

[0010] According to this invention, there is provided a condensation estimation means for estimating the level of risk of condensation on the radiation terminal after air conditioning operation is stopped, and after an instruction to stop air conditioning operation is issued by the instruction means, the control unit performs a predetermined condensation prevention operation to prevent condensation from occurring on the radiation terminal according to the level of risk of condensation estimated by the condensation estimation means, thereby preventing condensation from occurring on the radiation terminal after air conditioning operation is stopped and causing mold to grow, thereby improving product quality. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a configuration diagram showing the main units of a radiant cooling device according to a first embodiment of the present invention. [Figure 2] 1 is a configuration diagram showing the overall configuration of a first embodiment. [Figure 3] FIG. 2 is a control block diagram of the first embodiment. [Figure 4] 4 is a flowchart illustrating control after cooling operation is stopped in the first embodiment. [Figure 5] 10 is a flowchart illustrating control after cooling operation is stopped in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will be described below with reference to the accompanying drawings.

[0013] Example 1 Referring to Fig. 1, the radiant cooling device 1 includes a heat pump type heat source unit 10, a radiant panel 30, and a remote control 40. The heat pump type heat source unit 10 is connected by a refrigerant pipe 12 that constitutes a heat pump circuit 11. The radiation panel 30 serving as a radiation terminal is installed in the air-conditioned space 50 and is connected to the load-side circulation circuit 20 by a forward pipe 21 and a return pipe 22 . The remote control 40, which serves as an instruction means, is installed in the air-conditioned space 50 and is equipped with multiple switches and a screen (not shown). By pressing a switch that corresponds to the user's instruction, the screen display changes, operating the drive unit within the heat pump type heat source unit 10 and bringing it into a state that corresponds to the user's instruction.

[0014] Referring to Figure 2, the heat pump type heat source unit 10 has a circular refrigerant pipe 12 that constitutes a heat pump circuit 11. The refrigerant pipe 12 is provided with a compressor 13 as a drive unit with a variable rotation speed that compresses the refrigerant, an expansion valve 14 as a drive unit and pressure reducing means that reduces the pressure of the refrigerant, a heat source side heat exchanger 15 in which the refrigerant flowing inside exchanges heat with air blown by a blower fan 16 as a drive unit, and a four-way valve 18 that switches the flow direction of the refrigerant.

[0015] The heat pump type heat source machine 10 is also equipped with a discharge temperature sensor 17a that detects the temperature of the refrigerant discharged from the compressor 13, a heat exchanger temperature sensor 17b that detects the temperature of the refrigerant passing through the heat source side heat exchanger 15, an outside air temperature sensor 17c that detects the outside air temperature, and a control unit 19 that is composed of a microcomputer and has a memory unit and a calculation unit.

[0016] The load side circulation circuit 20 is equipped with a load side heat exchanger 23 connected to the refrigerant piping 12 and the supply pipe 21, a load side circulation pump 24 located in the piping and circulating a circulating fluid such as water or antifreeze, a cistern tank 25 capable of storing a predetermined amount of circulating fluid for pressure adjustment, a return temperature sensor 26a that detects the temperature of the circulating fluid flowing through the return pipe 22, and a supply temperature sensor 26b that detects the temperature of the circulating fluid flowing through the supply pipe 21.

[0017] The load-side heat exchanger 23 is a plate-type heat exchanger. This plate-type heat exchanger is made up of a plurality of stacked heat transfer plates, with refrigerant flow paths for circulating the refrigerant and fluid flow paths for circulating a fluid such as a circulating liquid alternately formed on either side of each heat transfer plate. This allows heat exchange between the refrigerant and the circulating liquid within the load-side heat exchanger 23.

[0018] The radiant panel 30 is installed as a wall surface, which is a predetermined component that constitutes the air-conditioned space 50, and radiant cooling is possible by flowing low-temperature circulating fluid inside. The radiant panel 30 is configured, for example, by placing piping through which the circulating fluid flows along the back of plywood or gypsum board used as an interior material, pasting wallpaper on the surface of the interior material, and arranging buffer material around the piping installed on the opposite side of the interior material. Furthermore, the radiant panel 30 is installed, for example, as part of a wall surface in the air-conditioned space 50, and by placing a bed in front of the radiant panel 30, localized cooling can be achieved during sleep. Since the radiant panel 30 is installed as a wall surface of the air-conditioned space 50, a drain receiver, which is a member for receiving condensation water, is not installed below the radiant panel 30. The temperature of the circulating fluid is adjusted so that condensation does not occur on the surface of the radiant panel 30. The number of radiation panels 30 is not limited to one, and multiple radiation panels 30 can be installed by adding additional supply pipes 21 and return pipes 22. When multiple radiation panels 30 are installed, the user can select the radiation panel 30 that will perform cooling operation using the remote control 40, and multiple radiation panels 30 can be operated in cooling mode simultaneously.

[0019] Referring to Fig. 3, the control unit 19 has condensation estimation means 19a that estimates the level of risk of condensation on the radiant panel 30 after the cooling operation, which performs radiant cooling by circulating low-temperature liquid inside the radiant panel 30, is stopped. The condensation estimation means 19a can estimate the risk of condensation on the radiant panel 30 from the values ​​detected by the outside air temperature sensor 17c and the return temperature sensor 26a when the cooling operation is stopped. Details will be described later.

[0020] The remote control 40 and the control unit 19 are connected by a communication line. When the remote control 40 receives an instruction from the user, the instruction is transmitted to the control unit 19, and the control unit 19 transmits the operation details of the drive unit in the heat pump heat source machine 10, thereby enabling the operation according to the instruction details received by the remote control 40 to be executed. In addition, the remote control 40 has a built-in humidity sensor 41 as a humidity detection means, which is capable of detecting the humidity within the air-conditioned space 50 in which the radiation panel 30 is installed, and when cooling operation is performed by the radiation panel 30, the detected value by the humidity sensor 41 is transmitted to the control unit 19.

[0021] Next, the control during cooling operation by the radiation panel 30 in the first embodiment will be described.

[0022] When a user operates an operation switch (not shown) on the remote control 40 to issue a command to start cooling operation, the control unit 19 confirms that the four-way valve 18 is positioned so that the refrigerant discharged from the compressor 13 flows into the heat source-side heat exchanger 15, and then drives the compressor 13 and the blower fan 16 of the heat pump circuit 11, as well as the load-side circulation pump 24 of the load-side circulation circuit 20. Then, based on the discharge pressure estimated from the value detected by the discharge temperature sensor 17a, the control unit 19 adjusts the opening of the expansion valve 14 to control the refrigerant to flow stably through the heat pump circuit 11.

[0023] As a result, the refrigerant that has passed through the expansion valve 14 on the heat pump circuit 11 side and has become low temperature and low pressure exchanges heat with the circulating liquid flowing in the load side circulation circuit 20 side in the load side heat exchanger 23, and the circulating liquid is cooled. The cooled low-temperature circulating liquid flows into the radiant panel 30 through the outgoing pipe 21, and the circulating liquid flows through multiple pipes (not shown) installed in the radiant panel 30. The low-temperature circulating liquid flows through the radiant panel 30, thereby performing radiant cooling, and the temperature around the radiant panel 30 drops.

[0024] During cooling operation, the control unit 19 constantly calculates the dew point temperature from the humidity of the air-conditioned space 50 detected by the humidity sensor 41 and the detection value of a temperature sensor (not shown) that detects the temperature of the air-conditioned space 50, and controls each drive unit in the heat pump type heat source unit 10 so that the detection value of the forward temperature sensor 26b is equal to or higher than the calculated dew point temperature. By controlling so that the detection value of the forward temperature sensor 26b is equal to or higher than the dew point temperature, the surface temperature of the radiant panel 30 is maintained at or higher than the dew point temperature, and condensation is prevented from occurring on the surface of the radiant panel 30.

[0025] Next, a problem with the radiation panel 30 after the cooling operation is stopped in the first embodiment will be described.

[0026] When a command to stop the cooling operation is issued by, for example, operating an operation stop switch (not shown) on the remote control 40 by the user, the control unit 19 stops the compressor 13 of the heat pump circuit 11 and also stops the load-side circulation pump 24 of the load-side circulation circuit 20, so as to prevent low-temperature circulating fluid from flowing into the radiant panel 30. When the cooling operation is performed using the radiant panel 30, particularly when the outside temperature is high, the large temperature difference between the inside and outside of the radiant panel 30, which is installed as part of a wall, causes condensation around the piping inside the radiant panel 30. Because the piping inside the radiant panel 30 is in contact with buffer material, if low-temperature circulating fluid remains inside the radiant panel 30 after the cooling operation is stopped, the condensation water may seep into the buffer material and cause mold to grow.

[0027] Furthermore, for a while after the cooling operation is stopped, low-temperature circulating fluid will remain inside the radiant panel 30. If the outside air temperature after the cooling operation is stopped is high, such as 30°C or higher, the indoor temperature of the air-conditioned space 50 in which the radiant panel 30 is installed will rise, and the difference between the temperature of the circulating fluid in the radiant panel 30 and the indoor temperature of the air-conditioned space 50 will become large. As a result, the temperature of the radiant panel 30 will become lower than the dew point temperature, and there is a risk that condensation will adhere to the surface of the radiant panel 30. If the radiant panel 30 installed as a wall surface of the air-conditioned space 50 is not provided with a member for collecting condensation adhering to the surface, if condensation continues to adhere to the surface of the radiant panel 30, it will drip from the radiant panel 30 and wet the floor surface of the air-conditioned space 50.

[0028] The present invention relates to a control that estimates the risk of condensation on the radiant panel 30 after cooling operation is stopped, and if the risk of condensation is high, performs a predetermined operation to prevent condensation on the radiant panel 30 and prevent problems caused by condensation. Specific control contents are described in detail below.

[0029] Next, the control content after the cooling operation by the radiant panel 30 in the first embodiment is stopped will be described with reference to the flowchart in FIG.

[0030] When the cooling operation is being performed by the radiant panel 30, the control unit 19 determines whether an instruction to stop the cooling operation has been issued by operating a switch on the remote control 40 or the like (step S101), and if it determines that an instruction to stop the cooling operation has been issued, it checks the detected value Tg of the outside air temperature sensor 17c and the detected value Tm of the return temperature sensor 26a (step S102). If the control unit 19 determines in step S101 that an instruction to stop the cooling operation has not been issued, it repeats the determination of step S101.

[0031] After confirming the detected value Tg of the outside air temperature sensor 17c and the detected value Tm of the return temperature sensor 26a in step S102, the control unit 19 determines whether the detected value Tg is equal to or greater than a predetermined high temperature value A stored in advance (step S103), and if it determines that the detected value Tg is equal to or greater than the predetermined high temperature value A, it determines whether the detected value Tm is equal to or less than a predetermined low temperature value B (step S104). If the control unit 19 determines in step S104 that the detected value Tm is equal to or less than the predetermined low temperature value B, the condensation estimation means 19a estimates that there is a high risk of condensation on the radiant panel 30 after the cooling operation is stopped, and the control unit 19 performs quick-drying operation, which is a predetermined condensation prevention operation that actively prevents condensation on the radiant panel 30 (step S105). The quick-drying operation will be described in detail later.

[0032] When the control unit 19 starts the quick-drying operation in step S105, it determines whether the quick-drying operation is completed when a predetermined time has elapsed since the start of the quick-drying operation and the drying of the radiation panel 30 is completed (step S106).If it determines that the quick-drying operation is completed, it stops the operation of the drive unit of the heat pump type heat source unit 10 to end the quick-drying operation, and if it determines that the quick-drying operation is not completed, it repeats the determination in step S106.

[0033] Furthermore, if the control unit 19 determines in step S103 that the detected value Tg is lower than the predetermined high temperature value A, or determines in step S104 that the detected value Tm is higher than the predetermined low temperature value B, the condensation estimation means 19a estimates that the risk of condensation on the radiant panel 30 after the cooling operation is stopped is low, and the control unit 19 carries out a normal drying operation, which is a predetermined condensation prevention operation that prevents condensation by replacing the circulating liquid in the radiant panel 30 (step S107). Details of the normal drying operation will be described later.

[0034] After starting the normal drying operation in step S107, the control unit 19 determines whether the normal drying operation has been completed by the passage of a predetermined time since the start of the normal drying operation and the replacement of the circulating liquid in the radiation panel 30 (step S108). If it determines that the normal drying operation has been completed, it stops the operation of the drive unit of the heat pump type heat source unit 10 to end the normal drying operation, and if it determines that the normal drying operation has not been completed, it repeats the determination in step S108.

[0035] Next, the quick drying operation will be described in detail.

[0036] 2 . When the quick-drying operation is to be performed in step S105, the control unit 19 operates the four-way valve 18 so that the high-temperature, high-pressure refrigerant discharged from the compressor 13 flows into the load-side heat exchanger 23. After the operation of the four-way valve 18 is completed, the control unit 19 drives the compressor 13 at the minimum rotation speed, opens the expansion valve 14 to a degree that matches the rotation speed of the compressor 13, and drives the load-side circulation pump 24, thereby performing the quick-drying operation. During the quick-drying operation, the circulating fluid is heated by heat exchange with the high-temperature refrigerant in the load-side heat exchanger 23, and the heated circulating fluid flows into the radiant panel 30, drying the inside of the radiant panel 30. After a predetermined time has elapsed that allows it to be determined that the drying of the inside of the radiant panel 30 has been completed, the control unit 19 stops the compressor 13 and the load-side circulation pump 24, thereby ending the quick-drying operation.

[0037] When quick-drying operation is performed, the temperature of the piping installed inside the radiant panel 30 rises, thereby reducing the risk of condensation around the piping inside the radiant panel 30 after cooling operation is stopped. If there is a high risk of condensation on the radiant panel 30 after cooling operation is stopped, quick-drying operation that actively dries the radiant panel 30 can be performed to prevent condensation around and on the surfaces of the piping through which the circulating liquid inside the radiant panel 30 flows.

[0038] Next, the normal drying operation will be described in detail.

[0039] See Fig. 2. When normal drying operation is to be performed in step S107, the control unit 19 drives only the load side circulation pump 24. When a time has elapsed since the start of driving the load side circulation pump 24 that is estimated to be the time when the low-temperature circulating liquid remaining in the radiation panel 30 has flowed out, the control unit 19 stops the load side circulation pump 24 and ends the normal drying operation.

[0040] When normal drying operation is performed, low-temperature circulating fluid flows out from inside the radiant panel 30, reducing the risk of condensation on the radiant panel 30 after cooling operation is stopped. If the risk of condensation on the radiant panel 30 is low after cooling operation is stopped and there is no need to actively dry the radiant panel 30, condensation can be prevented around and on the surfaces of the pipes through which the circulating fluid inside the radiant panel 30 flows by the simple measure of simply draining the low-temperature circulating fluid inside the radiant panel 30.

[0041] As described above, after the cooling operation is stopped, the condensation risk of the radiant panel 30 is estimated by the condensation estimation means 19a based on the detection value of the outside air temperature sensor 17c and the detection value of the return temperature sensor 26a. If it is estimated that the condensation risk is high, quick drying operation is performed, and if it is estimated that the condensation risk is low, normal drying operation is performed. This prevents a situation from occurring where low-temperature circulating liquid remains in the radiant panel 30 for a certain period of time after the cooling operation is stopped, causing condensation inside or on the surface of the radiant panel 30 due to the temperature difference with the outside air temperature or a rise in room temperature, resulting in the growth of mold.

[0042] Next, the effects of the first embodiment will be described.

[0043] The air conditioner includes condensation estimation means 19a that estimates the level of risk of condensation on the radiant panel 30, which serves as a radiant terminal, after cooling operation is stopped. After an instruction to stop cooling operation is issued by the remote control 40, which serves as an instruction means, the control unit 19 performs a predetermined condensation prevention operation to prevent condensation from occurring on the radiant panel 30, which serves as a radiant terminal, in accordance with the level of condensation risk estimated by the condensation estimation means 19a. After cooling operation is stopped, low-temperature circulating fluid remains in the radiant panel 30. Therefore, if the radiant panel 30 is installed as a wall surface of a house or the like, a large temperature difference between the outside air temperature or room temperature and the circulating fluid increases the risk of condensation around the piping through which the circulating fluid flows within the radiant panel 30 and on the surface of the radiant panel 30. By performing the predetermined condensation prevention operation based on the level of risk of condensation on the radiant panel 30 when cooling operation is stopped, condensation on the radiant panel 30 after cooling operation is stopped is prevented in advance, preventing mold growth due to condensation and improving product quality.

[0044] The predetermined condensation prevention operation is a quick-drying operation in which the heat pump type heat source device 10 is driven to heat the circulating fluid in the load-side heat exchanger 23 for a predetermined time and send the heated circulating fluid to the radiant panel 30 as a radiant terminal, and a normal drying operation in which the load-side circulation pump 24 is driven at least until the circulating fluid in the radiant panel 30 as a radiant terminal flows out. If the condensation estimation means 19a estimates a state in which the condensation risk is high, the control unit 19 performs the quick-drying operation, and if the condensation estimation means 19a estimates a state in which the condensation risk is low, the control unit 19 performs the normal drying operation. After the cooling operation is stopped, an appropriate predetermined condensation prevention operation is performed depending on the level of the condensation risk of the radiant panel 30, so that condensation and mold formation on the inside or surface of the radiant panel 30 due to changes in the indoor and outdoor environments after the cooling operation is stopped can be prevented, improving product quality.

[0045] Furthermore, if the detected value of the outside air temperature sensor 17c when the cooling operation is stopped is equal to or higher than a predetermined high temperature value and the detected value of the return temperature sensor 26a is equal to or lower than a predetermined low temperature value, the condensation estimation means 19a estimates that there is a high risk of condensation. If the difference between the outside air temperature and the temperature of the circulating fluid remaining in the radiant panel 30 is large because the outside air temperature is high and the temperature of the circulating fluid flowing out of the radiant panel 30 is low when the cooling operation is stopped, it can be estimated that there is a high risk of condensation on the radiant panel 30, so that the risk of condensation on the radiant panel 30 can be determined by simple means and appropriate predetermined condensation prevention operation can be carried out.

[0046] Furthermore, the radiant panel 30 as a radiant terminal is installed as a predetermined component that constitutes the air-conditioned space 50. When the radiant panel 30 is installed as a wall surface that is a component of the house that is the air-conditioned space 50, it may not be possible to install a drain receiver that receives condensation water generated on the radiant panel 30 and drains it outdoors. In such a radiant panel 30, a predetermined condensation prevention operation is performed according to the level of condensation risk after cooling operation is stopped, which is particularly useful because it can prevent condensation water from dripping onto the floor surface of the air-conditioned space 50 and causing wetness.

[0047] <Example 2> Next, the control content after the cooling operation by the radiant panel 30 in the second embodiment to which the present invention is applied is stopped will be described with reference to the flowchart in Fig. 5. Note that the configuration of the second embodiment is the same as that of the first embodiment, and therefore the description will be omitted.

[0048] When the cooling operation is being performed by the radiant panel 30, the control unit 19 determines whether an instruction to stop the cooling operation has been issued by operating a switch on the remote control 40 or the like (step S201), and if it determines that an instruction to stop the cooling operation has been issued, it checks the detected value Tg of the outside air temperature sensor 17c, the detected value Tm of the return temperature sensor 26a, and the detected humidity value H of the humidity sensor 41 (step S202). If the control unit 19 determines in step S201 that an instruction to stop the cooling operation has not been issued, it repeats the determination of step S201.

[0049] In step S202, the control unit 19 checks the detected value Tg from the outside air temperature sensor 17c, the detected value Tm from the return temperature sensor 26a, and the detected humidity value H from the humidity sensor 41, and then determines whether the detected value Tg is equal to or greater than a predetermined high temperature value A stored in advance (step S203). If it determines that the detected value Tg is equal to or greater than the predetermined high temperature value A, it determines whether the detected value Tm is equal to or less than a predetermined low temperature value B (step S204). If it determines that the detected value Tm is equal to or less than the predetermined low temperature value B, it determines whether the detected humidity value H is equal to or greater than a predetermined high humidity value C (step S205). If the control unit 19 determines in step S205 that the detected humidity value H is equal to or greater than the predetermined high humidity value C, the condensation estimation means 19a estimates that there is a high risk of condensation on the radiant panel 30 after the cooling operation is stopped, and the control unit 19 performs a quick-drying operation, which is a predetermined condensation prevention operation that actively prevents condensation on the radiant panel 30 (step S206). The details of the quick drying operation are the same as those in the first embodiment, so the explanation will be omitted.

[0050] When the control unit 19 starts the quick-drying operation in step S206, it determines whether the quick-drying operation is completed when a predetermined time has elapsed since the start of the quick-drying operation and the drying of the radiation panel 30 is completed (step S207).If it determines that the quick-drying operation is completed, it stops the operation of the drive unit of the heat pump type heat source unit 10 to end the quick-drying operation, and if it determines that the quick-drying operation is not completed, it repeats the determination in step S207.

[0051] Furthermore, if the control unit 19 determines in step S203 that the detected value Tg is lower than the predetermined high temperature value A, or determines in step S204 that the detected value Tm is higher than the predetermined low temperature value B, or determines in step S205 that the detected humidity value H is lower than the predetermined high humidity value C, the condensation estimation means 19a estimates that the risk of condensation on the radiant panel 30 after the cooling operation is stopped is low, and the control unit 19 carries out a normal drying operation, which is a predetermined condensation prevention operation that prevents condensation by replacing the circulating liquid in the radiant panel 30 (step S208). The details of the normal drying operation are the same as those in Example 1, so a description thereof will be omitted.

[0052] After starting the normal drying operation in step S208, the control unit 19 determines whether the normal drying operation has been completed by the passage of a predetermined time since the start of the normal drying operation and the replacement of the circulating liquid in the radiation panel 30 (step S209). If it determines that the normal drying operation has been completed, it stops the operation of the drive unit of the heat pump type heat source unit 10 to end the normal drying operation, and if it determines that the normal drying operation has not been completed, it repeats the determination in step S209.

[0053] As described above, after the cooling operation is stopped, the condensation risk of the radiant panel 30 is estimated by the condensation estimation means 19a based on the detection value of the outside air temperature sensor 17c and the detected humidity values ​​of the return temperature sensor 26a and the humidity sensor 41. If the condensation risk is estimated to be high, quick drying operation is performed, and if the condensation risk is estimated to be low, normal drying operation is performed. This prevents a situation from occurring where low-temperature circulating liquid remains in the radiant panel 30 for a certain period of time after the cooling operation is stopped, causing condensation inside or on the surface of the radiant panel 30 due to the temperature difference with the outside air temperature and the high humidity in the air-conditioned space 50, leading to the growth of mold.

[0054] Next, the effects of the second embodiment will be described. Note that the description of the effects common to the first embodiment will be omitted.

[0055] If the detected value of the outside air temperature sensor 17c when the cooling operation is stopped is equal to or higher than a predetermined high temperature value, the detected value of the return temperature sensor 26a is equal to or lower than a predetermined low temperature value, and the detected humidity value of the humidity sensor 41 serving as humidity detection means when the cooling operation is stopped is equal to or higher than a predetermined high humidity value, the condensation estimation means 19a estimates that there is a high risk of condensation. If there is a large temperature difference between the outside air temperature and the circulating fluid remaining in the radiant panel 30 when the cooling operation is stopped, and further if there is a high humidity in the air-conditioned space 50 in which the radiant panel 30 is installed, and the air-conditioned space 50 contains a large amount of moisture, it can be estimated that there is a high risk of condensation on the radiant panel 30, so that the risk of condensation on the radiant panel 30 can be determined by simple means, and appropriate predetermined condensation prevention operation can be performed.

[0056] Although several embodiments of the present invention have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the claims. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are within the scope and spirit of the invention, and are included in the inventions and their equivalents as defined in the claims.

[0057] For example, in the embodiment, the humidity sensor 41 is installed in the remote control 40 as the humidity detection means, but a temperature and humidity sensor capable of detecting the temperature and humidity of the air-conditioned space 50 may be installed. In this way, the temperature and humidity sensor detects the temperature and humidity of the air-conditioned space 50 when the cooling operation of the radiant panel 30 is stopped, and the temperature difference between the outside air temperature detected by the outside air temperature sensor 17c and the temperature of the air-conditioned space 50 is also confirmed, and if the temperature difference is greater than a predetermined value, it may be determined that there is a high risk of condensation on the radiant panel 30. Since the risk of condensation on the radiant panel 30 can be determined using not only the humidity but also the temperature of the air-conditioned space 50, it is possible to prevent condensation on the radiant panel 30 with high accuracy after the cooling operation is stopped.

[0058] Furthermore, in the embodiment, the wall surfaces as the predetermined components constituting the air-conditioned space 50 are installed as radiant panels 30, but this is not limited to this. For example, the floor and ceiling surfaces constituting the air-conditioned space 50 may be the predetermined components, and the entire floor or ceiling surface or a part of the floor or ceiling surface may be installed as radiant panels 30. When radiant panels 30 are installed as the predetermined components constituting the air-conditioned space 50, it may be difficult to install a drain pan for receiving condensation water on the radiant panel 30, and in such radiant panels 30, the application of the present invention, which performs a predetermined condensation prevention operation according to the level of condensation risk after cooling operation is stopped, is particularly useful. [Explanation of symbols]

[0059] 1 Radiant cooling system 10 Heat pump type heat source machine 11 Heat pump circuit 13 Compressor 14 Expansion valve 15 Heat source side heat exchanger 17c Outside air temperature sensor 19 Control Unit 19a Condensation estimation method 20 Load side circulation circuit 23 Load side heat exchanger 24 Load side circulation pump 26a Return temperature sensor 30 Radiation Panel 40 Remote Control 41 Humidity Sensor 50 Air-conditioned space

Claims

1. a heat pump type heat source machine including a compressor that compresses a refrigerant, a load-side heat exchanger that exchanges heat between a circulating liquid and the refrigerant, a pressure reducing means, and a heat source-side heat exchanger; a load-side circulation circuit in which the load-side heat exchanger, a load-side circulation pump for circulating the circulating fluid, and a radiation terminal through which the circulating fluid flows by driving the load-side circulation pump are connected in a ring shape by piping; an instruction means for issuing an instruction to start and stop a cooling operation in which the circulating fluid cooled by driving the heat pump type heat source machine is circulated in the radiation terminal to cool the surroundings; a control unit that drives the heat pump type heat source machine and the load side circulation pump when the instruction means issues an instruction to start the cooling operation, a condensation estimation means for estimating a level of a condensation risk at the radiation terminal after the cooling operation is stopped, A radiant cooling device characterized in that after the instruction means issues an instruction to stop the air conditioning operation, the control unit performs a predetermined condensation prevention operation to prevent condensation from occurring on the radiant terminal, depending on the level of the condensation risk estimated by the condensation estimation means.

2. The predetermined dew condensation prevention operation is a quick-drying operation in which the heat pump type heat source machine is driven to heat the circulating fluid in the load-side heat exchanger for a predetermined time and the heated circulating fluid is sent to the radiation terminal; a normal drying operation in which the load-side circulation pump is driven at least until the circulating liquid in the radiation terminal flows out; When the condensation estimation means estimates that the condensation risk is high, the control unit performs the quick drying operation, The radiant cooling device according to claim 1 , wherein the control unit performs the normal drying operation when the condensation estimating means estimates that the risk of condensation is low.

3. an outside air temperature sensor that detects the outside air temperature; a return temperature sensor for detecting the temperature of the circulating fluid flowing out from the radiation terminal; 3. The radiant cooling device of claim 2, wherein if the detected value of the outside air temperature sensor when the cooling operation is stopped is equal to or higher than a predetermined high temperature value and the detected value of the return temperature sensor is equal to or lower than a predetermined low temperature value, the condensation estimation means estimates that the risk of condensation is high.

4. an outside air temperature sensor that detects the outside air temperature; a return temperature sensor that detects the temperature of the circulating fluid flowing out from the radiation terminal; and humidity detection means for detecting humidity in an air-conditioned space in which the radiation terminal is installed, 3. The radiant cooling device according to claim 2, wherein if the detected value of the outside air temperature sensor when the cooling operation is stopped is equal to or higher than a predetermined high temperature value, the detected value of the return temperature sensor is equal to or lower than a predetermined low temperature value, and the detected value of the humidity detection means when the cooling operation is stopped is equal to or higher than a predetermined high humidity value, the condensation estimation means estimates that the risk of condensation is high.

5. The radiant cooling device according to any one of claims 1 to 4, wherein the radiant terminal is installed as a predetermined member constituting an air-conditioned space.

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