Temperature control device

Abstract

To provide a temperature control device capable of enhancing a performance coefficient and cooling efficiency while preventing liquid compression.SOLUTION: A temperature control device 2 includes: a compressor 4; a first pressure sensor 6 disposed on a side on which a CO2 refrigerant flows out from the compressor 4; a second pressure sensor 8 disposed on a side on which the CO2 refrigerant flows into the compressor 4; a branch part 14 for branching the CO2 refrigerant flowing out from the compressor 4 to a first route 10 and a second route 12; and control means 16. The first route 10 includes a first CO2 refrigerant control valve 18, a first heat exchanger 20, a first internal heat exchanger 22, a variable expansion valve 24, a second internal heat exchanger 26, a second heat exchanger 28, a first auxiliary passage 30, and a first return passage 32. The second route 12 includes a second CO2 refrigerant control valve 58, the second heat exchanger 28, the second internal heat exchanger 26, the variable expansion valve 24, the first internal heat exchanger 22, the first heat exchanger 20, a second auxiliary passage 60, and a second return passage 62.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a temperature control device that cools or heats functional water to control the temperature of the functional water.

Background Art

[0002] A wafer on which a plurality of devices such as ICs and LSIs are partitioned by a division planned line and formed on the surface is ground on the back surface by a grinding device to form a predetermined thickness, and then divided into individual device chips by a dicing device, a laser processing device, etc. Each of the divided device chips is used in electrical devices such as mobile phones and personal computers.

[0003] When processing the wafer, if the spindle unit equipped with the cutting tool that constitutes the grinding device or the dicing device generates heat and thermally expands, high-precision grinding or cutting cannot be performed. Therefore, control is performed by a cooling device to keep the temperature of the spindle unit constant (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The cooling device described in Patent Document 1 above is a type of device that uses CO 2 as a refrigerant and can obtain high cooling efficiency. However, if the water temperature of the functional water used in the processing device (including disposable processing water such as cutting water and circulating water used for cooling the spindle, etc.) is set low, the refrigerant sucked into the compressor may not be completely vaporized, resulting in liquid compression, which may shorten the life of the compressor.

[0006] When a grinding device or a dicing device is used in a cold region, the temperature of the functional water may become lower than a predetermined temperature. In such a case, it is necessary to heat the functional water to the predetermined temperature by an electric heater. However, the heating capacity of the electric heater corresponds to the power consumption, and there is a problem that the coefficient of performance (heating capacity / power consumption) is as small as 1.

[0007] An object of the present invention is to provide a temperature control device that can increase the coefficient of performance and the cooling efficiency while preventing liquid compression.

Means for Solving the Problems

[0008] According to the present invention, the following temperature control device for solving the above problems is provided. That is, A temperature control device for cooling or heating functional water to control the temperature of the functional water, CO 2 A compressor for compressing the refrigerant, A first pressure sensor disposed on the side where the refrigerant flows out from the compressor to CO 2 A second pressure sensor disposed on the side where the refrigerant flows into the compressor to CO CO to the compressor 2 A branch portion that branches the refrigerant flowing out from the compressor into a first path and a second path, The CO flowing out from the compressor 2 A branch portion that branches the refrigerant into a first path and a second path, Comprising a control means, The first path is CO 2 A first CO for adjusting the flow rate of the refrigerant 2 Refrigerant control valve, The first CO 2 The CO that has passed through the refrigerant control valve 2 A first heat exchanger that gives heat from the refrigerant to the functional water, The CO that has passed through the first heat exchanger 2 A first internal heat exchanger that allows the refrigerant to pass through, The CO that has passed through the first internal heat exchanger 2 A variable expansion valve that expands the refrigerant, The CO that has passed through the variable expansion valve 2a second internal heat exchanger through which the refrigerant passes; CO that has passed through the second internal heat exchanger 2 a second heat exchanger in which the refrigerant takes heat from industrial water; CO that has passed through the second heat exchanger 2 a first return path that guides the refrigerant to the first internal heat exchanger and through which CO flows out from the first heat exchanger 2 a first auxiliary path that takes heat from the refrigerant and through which CO passes through the second heat exchanger 2 liquid CO remaining in the refrigerant 2 a first auxiliary path for vaporizing the refrigerant; CO from the first auxiliary path 2 a first return path that guides the refrigerant to the compressor, and comprising; the second forward path is CO 2 a second CO for adjusting the flow rate of the refrigerant 2 a refrigerant control valve; the second CO 2 CO that has passed through the refrigerant control valve 2 the second heat exchanger that gives heat from the refrigerant to industrial water; CO that has passed through the second heat exchanger 2 the second internal heat exchanger through which the refrigerant passes; CO that has passed through the second internal heat exchanger 2 the variable expansion valve for expanding the refrigerant; CO that has passed through the variable expansion valve 2 the first internal heat exchanger through which the refrigerant passes; CO that has passed through the first internal heat exchanger 2 the first heat exchanger in which the refrigerant takes heat from functional water; CO that has passed through the first heat exchanger 2 a second return path that guides the refrigerant to the second internal heat exchanger and through which CO flows out from the second heat exchanger 2 a second auxiliary path that takes heat from the refrigerant and through which CO passes through the first heat exchanger 2 liquid CO remaining in the refrigerant 2 a second auxiliary path for vaporizing the refrigerant; CO from the second auxiliary path 2 a second return path that guides the refrigerant to the compressor, and a temperature control device is provided.

[0009] Preferably, the first auxiliary path includes a first on-off valve that opens and closes the first main path after the second heat exchanger, and a second on-off valve and a third on-off valve arranged so as to sandwich the first on-off valve. The second auxiliary path includes a fourth on-off valve that opens and closes the second main path after the first heat exchanger, and a fifth on-off valve and a sixth on-off valve arranged so as to sandwich the fourth on-off valve. The control means When guiding CO 2 refrigerant to the first main path, open the first CO 2 refrigerant control valve, close the second CO 2 refrigerant control valve, open the fourth on-off valve, close the fifth on-off valve and the sixth on-off valve, close the first on-off valve, and open the second on-off valve and the third on-off valve. When guiding CO 2 refrigerant to the second main path, open the second CO 2 refrigerant control valve, close the first CO 2 refrigerant control valve, open the first on-off valve, close the second on-off valve and the third on-off valve, close the fourth on-off valve, and open the fifth on-off valve and the sixth on-off valve.

[0010] A third CO 2 refrigerant control valve is arranged in the first return path, and a fourth CO 2 refrigerant control valve is arranged in the second return path. The control means When guiding CO 2 refrigerant to the first main path, open the third CO 2 refrigerant control valve, close the fourth CO 2 refrigerant control valve. When guiding CO 2 refrigerant to the second main path, it is desirable to open the fourth CO 2 refrigerant control valve and close the third CO 2 refrigerant control valve.

[0011] When the control means heats the functional water by adopting the first main path, the first CO2 The refrigerant control valve and the third CO 2 Set the refrigerant control valve to fully open, The second CO 2 The refrigerant control valve and the fourth CO 2 Set the refrigerant control valve to fully closed, Function the first heat exchanger as a gas cooler to CO 2 Heat the functional water with the refrigerant, Function the second heat exchanger as an evaporator to CO 2 Let the refrigerant take heat from the industrial water, The CO flowing out from the first heat exchanger 2 Make the refrigerant pass through the first internal heat exchanger and the CO flowing out from the second heat exchanger 2 Give heat to the refrigerant and the CO flowing out from the second heat exchanger 2 The liquid CO remaining in the refrigerant 2 Vaporize the refrigerant to reduce the load of the compressor, In addition to increasing or decreasing the rotational speed of the compressor to increase or decrease the heating amount of the functional water so that the temperature of the first temperature sensor for detecting the temperature of the functional water flowing into the first heat exchanger or the second temperature sensor for detecting the temperature of the functional water flowing out from the first heat exchanger becomes a predetermined temperature, increase the coefficient of performance by changing the opening degree of the variable expansion valve so that the detected value of the first pressure sensor becomes a predetermined pressure value, It is preferable to control the water control valve that controls the amount of industrial water flowing into the second heat exchanger so that the temperature difference between the temperature of the third temperature sensor for detecting the temperature of the industrial water flowing into the second heat exchanger and the temperature of the fourth temperature sensor for detecting the temperature of the industrial water flowing out from the second heat exchanger becomes constant, thereby suppressing waste of the industrial water.

[0012] When the control means reduces the heating amount of the functional water, Lower the rotational speed of the compressor. When the rotational speed of the compressor reaches the minimum rotational speed, further reduce the heating amount by the second CO 2 Gradually increase the opening degree of the refrigerant control valve from fully closed, The second CO 2By increasing the opening degree of the refrigerant control valve, the detected value of the second pressure sensor is increased. At this time, the opening degree of the variable expansion valve is decreased so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. the second CO 2 When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently the fourth CO 2 The opening degree of the refrigerant control valve is gradually increased from fully closed, and the opening degree of the variable expansion valve can be further decreased so that the detected value of the first pressure sensor is maintained at a predetermined pressure value.

[0013] When the control means sets the heating amount of the functional water to 0, the second CO 2 When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently the fourth CO 2 The opening degree of the refrigerant control valve is gradually increased from fully closed, and the opening degree of the variable expansion valve is further decreased and closed completely so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. CO in the first path and the second path 2 Since the refrigerant does not circulate, the functional water may not be heated or cooled.

[0014] When the control means cools the functional water by adopting the second path, the second CO 2 the refrigerant control valve and the fourth CO 2 The refrigerant control valve is fully opened, the first CO 2 the refrigerant control valve and the third CO 2 The refrigerant control valve is fully closed, The second heat exchanger functions as a gas cooler to take heat from the CO by industrial water, 2 The first heat exchanger functions as an evaporator to take heat from the functional water by the CO, 2 The CO flowing out from the second heat exchanger 2 The refrigerant passes through the second internal heat exchanger so as to give heat to the CO flowing out from the first heat exchanger, 2 2 liquid CO remaining in the refrigerant​​​2 Vaporize the refrigerant to reduce the load on the compressor, In addition to increasing or decreasing the rotational speed of the compressor to increase or decrease the cooling capacity of the functional water so that the temperature of the first temperature sensor that detects the temperature of the functional water flowing into the first heat exchanger or the second temperature sensor that detects the temperature of the functional water flowing out of the first heat exchanger reaches a predetermined temperature, increase the cooling efficiency by changing the opening degree of the variable expansion valve so that the detected value of the first pressure sensor becomes a predetermined pressure value, CO flowing out of the second heat exchanger 2 Based on the temperature of the third temperature sensor that detects the temperature of the industrial water flowing into the second heat exchanger, it is convenient to control the water control valve that controls the amount of industrial water flowing into the second heat exchanger to adjust the flow rate of the industrial water so that the temperature of the fifth temperature sensor that detects the temperature of the refrigerant becomes a predetermined temperature.

[0015] When the control means reduces the cooling capacity of the functional water, Lower the rotational speed of the compressor. When the rotational speed of the compressor reaches the minimum rotational speed, to further reduce the cooling capacity, gradually increase the opening degree of the first CO 2 refrigerant control valve from fully closed, By increasing the opening degree of the first CO 2 refrigerant control valve, increase the detected value of the second pressure sensor. At this time, reduce the opening degree of the variable expansion valve so that the detected value of the first pressure sensor is maintained at a predetermined pressure value, the first CO 2 When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently gradually increase the opening degree of the third CO 2 refrigerant control valve from fully closed and further reduce the opening degree of the variable expansion valve so that the detected value of the first pressure sensor is maintained at a predetermined pressure value, which is desirable.

[0016] When the control means sets the cooling capacity of the functional water to 0, the first CO 2 When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently gradually increase the opening degree of the third CO 2Gradually increase the opening degree of the refrigerant control valve from fully closed, and further reduce and fully close the opening degree of the variable expansion valve so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. CO in the first flow path and the second flow path 2 Since the refrigerant does not circulate, it is preferable that the functional water is neither cooled nor heated.

Advantages of the Invention

[0017] The temperature control device of the present invention is a temperature control device that cools or heats functional water to control the temperature of the functional water, CO 2 a compressor that compresses the refrigerant, from the compressor to CO 2 a first pressure sensor disposed on the side where the refrigerant flows out, to the compressor to CO 2 a second pressure sensor disposed on the side where the refrigerant flows in, the CO flowing out from the compressor 2 a branch portion that branches the refrigerant into a first flow path and a second flow path, control means, and is provided with the first flow path is CO 2 a first CO that adjusts the flow rate of the refrigerant 2 refrigerant control valve, the first CO 2 the CO that has passed through the first refrigerant control valve 2 a first heat exchanger that gives heat from the refrigerant to the functional water, the CO that has passed through the first heat exchanger 2 a first internal heat exchanger that allows the refrigerant to pass through, the CO that has passed through the first internal heat exchanger 2 a variable expansion valve that expands the refrigerant, the CO that has passed through the variable expansion valve 2 a second internal heat exchanger that allows the refrigerant to pass through, the CO that has passed through the second internal heat exchanger 2 a second heat exchanger that the refrigerant takes heat from industrial water, the CO that has passed through the second heat exchanger 2The refrigerant is guided to the first internal heat exchanger, and the CO that has flowed out of the first heat exchanger 2 takes heat from the refrigerant and the CO that has passed through the second heat exchanger 2 the liquid CO remaining in the refrigerant 2 a first auxiliary path for vaporizing the refrigerant, and the CO from the first auxiliary path 2 a first return path for guiding the refrigerant to the compressor, and is provided with The second forward path is CO 2 a second CO for adjusting the flow rate of the refrigerant 2 a refrigerant control valve, and the second CO 2 the CO that has passed through the refrigerant control valve 2 the second heat exchanger that gives heat from the refrigerant to industrial water, and the CO that has passed through the second heat exchanger 2 the second internal heat exchanger through which the refrigerant passes, and the CO that has passed through the second internal heat exchanger 2 the variable expansion valve for expanding the refrigerant, and the CO that has passed through the variable expansion valve 2 the first internal heat exchanger through which the refrigerant passes, and the CO that has passed through the first internal heat exchanger 2 the first heat exchanger where the refrigerant takes heat from the functional water, and the CO that has passed through the first heat exchanger 2 The refrigerant is guided to the second internal heat exchanger, and the CO that has flowed out of the second heat exchanger 2 takes heat from the refrigerant and the CO that has passed through the first heat exchanger 2 the liquid CO remaining in the refrigerant 2 a second auxiliary path for vaporizing the refrigerant, and the CO from the second auxiliary path 2 a second return path for guiding the refrigerant to the compressor, so that while preventing liquid compression, the coefficient of performance and the cooling efficiency can be increased.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0019] Hereinafter, a preferred embodiment of the temperature control device according to the present invention will be described with reference to the drawings.

[0020] (Temperature control device 2) FIG. 1 shows a temperature control device 2 that cools or heats functional water (for example, pure water) to control the temperature of the functional water. The temperature control device 2 includes a compressor 4 that compresses a CO 2 refrigerant, a first pressure sensor 6 disposed on the side where the CO 2 refrigerant flows out from the compressor 4, a second pressure sensor 8 disposed on the side where the CO 2 refrigerant flows into the compressor 4, a branch portion 14 that branches the CO 2 refrigerant flowing out from the compressor 4 into a first route 10 and a second route 12, and a control means 16.

[0021] (Compressor 4) The compressor 4 is a CO that circulates through the temperature control device 2 2The compressor 4 compresses the refrigerant. As shown in Fig. 1, the motor 4a that drives the compressor 4 is provided with an inverter 4b. The inverter 4b changes the frequency of the power supplied to the motor 4a within a predetermined range (for example, 20 Hz to 120 Hz). This changes the rotation speed of the motor 4a and changes the rotation speed of the compressor 4 within the range of the allowable rotation speed (between the minimum rotation speed and the maximum rotation speed). The inverter 4b is electrically connected to the control means 16 and is controlled by the control means 16.

[0022] (First and second pressure sensors 6 and 8) The first pressure sensor 6 detects the amount of CO 2 It is arranged in the pipe on the side where the refrigerant flows out, and CO 2 Refrigerant (CO after compression 2 On the other hand, the second pressure sensor 8 detects the pressure of the refrigerant (CO 2 The refrigerant is supplied to the compressor 4 via a pipe. 2 Refrigerant (CO before compression 2 The detection values ​​of the first and second pressure sensors 6, 8 are sent to the control means 16.

[0023] (First Route 10) Referring to FIG. 2, the first route 10 includes a first CO 2 The refrigerant control valve 18 includes a first heat exchanger 20, a first internal heat exchanger 22, a variable expansion valve 24, a second internal heat exchanger 26, a second heat exchanger 28, a first auxiliary path 30, and a first return path 32. In this embodiment, the first and second heat exchangers 20, 28, the first and second internal heat exchangers 22, 26, and the variable expansion valve 24 are common components in the first and second paths 10, 12.

[0024] (First CO 2 Refrigerant control valve18) First CO 2 The refrigerant control valve 18 controls the flow of CO 2 from the compressor 4 through the first path 10. 2 Adjust the flow rate of the refrigerant. First CO 2The motor 18a that adjusts the opening degree of the refrigerant control valve 18 is electrically connected to the control means 16. And the first CO 2 The opening degree of the refrigerant control valve 18 is adjusted by the motor 18a based on an instruction from the control means 16.

[0025] (First heat exchanger 20) In the first heat exchanger 20 in the first flow path 10, the first CO 2 The CO that has passed through the refrigerant control valve 18 2 Gives heat from the refrigerant to the functional water. In the first heat exchanger 20, there are formed a refrigerant passage 20a through which the CO refrigerant passes and a functional water passage 20b through which the functional water passes. The functional water passage 20b is connected to the functional water supply source 34 and the processing device 36. The processing device 36 connected to the functional water passage 20b may be one or a plurality. And in the first heat exchanger 20 in the first flow path 10, heat exchange occurs between the CO refrigerant in the refrigerant passage 20a compressed by the compressor 4 and the functional water in the functional water passage 20b, so that the first CO 2 Gives heat from the refrigerant that has passed through the refrigerant control valve 18 to the functional water. 2 Refrigerant and the functional water in the functional water passage 20b, so that the first CO 2 The CO that has passed through the refrigerant control valve 18 2 Gives heat from the refrigerant to the functional water.

[0026] As shown in FIG. 1, between the first heat exchanger 20 and the functional water supply source 34, a first temperature sensor 38 for detecting the temperature of the functional water flowing into the first heat exchanger 20 is provided. Also, between the first heat exchanger 20 and the processing device 36, a second temperature sensor 40 for detecting the temperature of the functional water flowing out of the first heat exchanger 20 is provided. The detected values of the first and second temperature sensors 38 and 40 are both sent to the control means 16.

[0027] Note that the functional water (waste water) discharged from the processing device 36 may be returned to the functional water supply source 34, or may be discarded without being returned to the functional water supply source 34. When returning the waste water of the processing device 36 to the functional water supply source 34, a functional water purification means (not shown) for purifying the waste water of the processing device 36 into required functional water (pure water) is provided in the path for returning the waste water of the processing device 36 to the functional water supply source 34. The functional water purification means may be, for example, a pure water purification means including a filter that filters the waste water of the processing device 36 to generate clean water, an ultraviolet irradiator that destroys organic substances contained in the clean water filtered by the filter, and an ion exchange resin that generates pure water from the clean water irradiated with ultraviolet rays by the ultraviolet irradiator.

[0028] (First internal heat exchanger 22) The first internal heat exchanger 22 in the first main path 10 allows the CO that has passed through the first heat exchanger 20 2 to pass through the refrigerant. The first internal heat exchanger 22 is provided with a main passage 22a for allowing the CO that has passed through the first heat exchanger 20 2 to pass through the refrigerant, and a sub-passage 22b communicating with the first auxiliary path 30.

[0029] (Variable expansion valve 24) The variable expansion valve 24 in the first main path 10 expands the CO that has passed through the first internal heat exchanger 22 2 refrigerant. A motor 24a for adjusting the opening degree of the variable expansion valve 24 is electrically connected to the control means 16. Then, the opening degree of the variable expansion valve 24 is adjusted by the motor 24a based on an instruction from the control means 16.

[0030] (Second internal heat exchanger 26) The second internal heat exchanger 26 in the first main path 10 allows the CO that has passed through the variable expansion valve 24 2 to pass through the refrigerant. The second internal heat exchanger 26 is provided with a main passage 26a for allowing the CO that has passed through the variable expansion valve 24 2 to pass through the refrigerant, and a sub-passage 26b communicating with a second auxiliary path 60 described later.

[0031] (Second heat exchanger 28) In the second heat exchanger 28 in the first flow path 10, the CO that has passed through the second internal heat exchanger 26 2 refrigerant takes heat from the industrial water. The second heat exchanger 28 is formed with a refrigerant passage 28a through which the CO 2 refrigerant passes and an industrial water passage 28b through which the industrial water passes. The industrial water passage 28b is connected to the industrial water supply source 42. And in the second heat exchanger 28 in the first flow path 10, the CO in the refrigerant passage 28a expanded by the variable expansion valve 24 2 heat exchange occurs between the refrigerant and the industrial water in the industrial water passage 28b, so that the CO that has passed through the second internal heat exchanger 26 2 refrigerant takes heat from the industrial water and vaporizes. However, a part of the CO 2 refrigerant may have liquid remaining.

[0032] As shown in FIG. 1, a water control valve 44 for adjusting the amount of industrial water flowing into the second heat exchanger 28 is provided between the second heat exchanger 28 and the industrial water supply source 42. A motor 44a for adjusting the opening degree of the water control valve 44 is electrically connected to the control means 16. And the opening degree of the water control valve 44 is adjusted by the motor 44a based on an instruction from the control means 16.

[0033] Also, a third temperature sensor 46 for detecting the temperature of the industrial water flowing into the second heat exchanger 28 is provided between the second heat exchanger 28 and the industrial water supply source 42. On the other hand, a fourth temperature sensor 48 for detecting the temperature of the industrial water flowing out of the second heat exchanger 28 is provided on the outlet side of the industrial water passage 28b of the second heat exchanger 28. The detected values of the third and fourth temperature sensors 46 and 48 are both sent to the control means 16.

[0034] (First auxiliary path 30) The first auxiliary path 30 is the CO that has passed through the second heat exchanger 28 2It is a path for guiding the refrigerant to the first internal heat exchanger 22. The first auxiliary path 30 includes a first on-off valve 50 that opens and closes the first main path 10 after the second heat exchanger 28, and a second on-off valve 52 and a third on-off valve 54 disposed so as to sandwich the first on-off valve 50. Motors 50a, 52a, and 54a for adjusting the opening degrees of the first, second, and third on-off valves 50, 52, and 54 are electrically connected to the control means 16. Then, the opening degrees of the first, second, and third on-off valves 50, 52, and 54 are adjusted by the respective motors 50a, 52a, and 54a based on instructions from the control means 16.

[0035] In the first auxiliary path 30, when CO 2 refrigerant is introduced, the first on-off valve 50 is closed and the second and third on-off valves 52 and 54 are opened. Then, the CO 2 refrigerant that has passed through the second heat exchanger 28 is guided to the sub-passage 22b of the first internal heat exchanger 22 through the second on-off valve 52. As a result, in the first internal heat exchanger 22, heat exchange is performed between the CO 2 refrigerant in the sub-passage 22b that has passed through the second heat exchanger 28 and the CO 2 refrigerant in the main passage 22a that has flowed out of the first heat exchanger 20. That is, the CO 2 refrigerant in the sub-passage 22b takes heat from the CO 2 refrigerant in the main passage 22a. As a result, the liquid CO 2 refrigerant remaining in the CO 2 refrigerant that has passed through the second heat exchanger 28 all vaporizes.

[0036] (First return path 32) The first return path 32 is a path for guiding the CO 2 refrigerant from the first auxiliary path 30 to the compressor 4. A third CO 2 refrigerant control valve 56 is disposed in the first return path 32. A motor 56a for adjusting the opening degree of the third CO 2 refrigerant control valve 56 is electrically connected to the control means 16. Then, the opening degree of the third CO 2 refrigerant control valve 56 is adjusted by the motor 56a based on instructions from the control means 16.

[0037] (Second bypass route 12) Referring to FIG. 6, the second bypass route 12 includes a second CO 2 refrigerant control valve 58, a second heat exchanger 28, a second internal heat exchanger 26, a variable expansion valve 24, a first internal heat exchanger 22, a first heat exchanger 20, a second auxiliary path 60, and a second return path 62.

[0038] (Second CO 2 (refrigerant control valve 58) Second CO 2 The refrigerant control valve 58 adjusts the flow rate of the CO 2 refrigerant led from the compressor 4 to the second bypass route 12. The second CO 2 motor 58a for adjusting the opening degree of the refrigerant control valve 58 is electrically connected to the control means 16. And the second CO 2 opening degree of the refrigerant control valve 58 is adjusted by the motor 58a based on an instruction from the control means 16.

[0039] (Second heat exchanger 28) In the second heat exchanger 28 in the second bypass route 12, the second CO 2 CO passing through the refrigerant control valve 58 2 gives heat to industrial water from the refrigerant. That is, in the second heat exchanger 28 in the second bypass route 12, heat exchange is performed between the CO 2 refrigerant in the refrigerant passage 28a compressed by the compressor 4 and the industrial water in the industrial water passage 28b, so that the second CO 2 CO passing through the refrigerant control valve 58 2 gives heat to industrial water from the refrigerant.

[0040] As shown in FIG. 6, between the second heat exchanger 28 and the second internal heat exchanger 26, a fifth temperature sensor 64 for detecting the temperature of the CO 2 refrigerant flowing out from the second heat exchanger 28 is provided. The detection value of the fifth temperature sensor 64 is sent to the control means 16.

[0041] (Second internal heat exchanger 26) The second internal heat exchanger 26 in the second path 12 allows the CO 2 refrigerant that has passed through the second heat exchanger 28 to pass through. Specifically, the CO 2 refrigerant that has passed through the second heat exchanger 28 passes through the main passage 26a of the second internal heat exchanger 26. Further, as will be described later, the CO 2 refrigerant that has passed through the first heat exchanger 20 passes through the sub-passage 26b of the second internal heat exchanger 26.

[0042] (Variable expansion valve 24) The variable expansion valve 24 in the second path 12 expands the CO 2 refrigerant that has passed through the second internal heat exchanger 26.

[0043] (First internal heat exchanger 22) The first internal heat exchanger 22 in the second path 12 allows the CO 2 refrigerant that has passed through the variable expansion valve 24 to pass through. Specifically, the CO 2 refrigerant that has passed through the variable expansion valve 24 passes through the main passage 22a of the first internal heat exchanger 22.

[0044] (First heat exchanger 20) In the first heat exchanger 20 in the second path 12, the CO 2 refrigerant takes heat from the functional water. That is, in the first heat exchanger 20 in the second path 12, heat exchange occurs between the CO 2 refrigerant in the refrigerant passage 20a expanded by the variable expansion valve 24 and the functional water in the functional water passage 20b, so that the CO 2 refrigerant that has passed through the first internal heat exchanger 22 takes heat from the functional water and vaporizes, and the functional water is cooled. However, in the case of the CO 2 refrigerant, a part of the liquid may remain.

[0045] (Second auxiliary path 60) The second auxiliary path 60 is for the CO 2It is a path for guiding the refrigerant to the second internal heat exchanger 26. The second auxiliary path 60 includes a fourth on-off valve 66 that opens and closes the second forward path 12 after the first heat exchanger 20, and a fifth on-off valve 68 and a sixth on-off valve 70 arranged so as to sandwich the fourth on-off valve 66. Motors 66a, 68a, and 70a for adjusting the opening degrees of the fourth, fifth, and sixth on-off valves 66, 68, and 70 are electrically connected to the control means 16. Then, the opening degrees of the fourth, fifth, and sixth on-off valves 66, 68, and 70 are adjusted by the respective motors 66a, 68a, and 70a based on instructions from the control means 16.

[0046] In the second auxiliary path 60, when the refrigerant is guided to the second forward path 12, the fourth on-off valve 66 is closed, and the fifth and sixth on-off valves 68 and 70 are opened. Then, the refrigerant that has passed through the first heat exchanger 20 is guided to the sub-passage 26b of the second internal heat exchanger 26 through the fifth on-off valve 68. As a result, in the second internal heat exchanger 26, heat exchange is performed between the refrigerant in the sub-passage 26b that has passed through the first heat exchanger 20 and the refrigerant in the main passage 26a that has flowed out of the second heat exchanger 28. That is, the refrigerant in the sub-passage 26b takes heat from the refrigerant in the main passage 26a. As a result, all the liquid refrigerant remaining in the refrigerant that has passed through the first heat exchanger 20 vaporizes. 2 When the refrigerant is guided, the fourth on-off valve 66 is closed, and the fifth and sixth on-off valves 68 and 70 are opened. Then, the CO refrigerant that has passed through the first heat exchanger 20 is guided to the sub-passage 26b of the second internal heat exchanger 26 through the fifth on-off valve 68. 2 Thereby, in the second internal heat exchanger 26, heat exchange is performed between the CO refrigerant in the sub-passage 26b that has passed through the first heat exchanger 20 and the CO refrigerant in the main passage 26a that has flowed out of the second heat exchanger 28. 2 That is, the CO refrigerant in the sub-passage 26b takes heat from the CO refrigerant in the main passage 26a. 2 As a result, all the liquid CO refrigerant remaining in the CO refrigerant that has passed through the first heat exchanger 20 vaporizes. 2 2 2 2

[0047] (Second return path 62) The second return path 62 is a path for guiding the refrigerant from the second auxiliary path 60 to the compressor 4. A fourth refrigerant control valve 72 is arranged in the second return path 62. A motor 72a for adjusting the opening degree of the fourth refrigerant control valve 72 is electrically connected to the control means 16. Then, the opening degree of the fourth refrigerant control valve 72 is adjusted by the motor 72a based on instructions from the control means 16. 2 The second return path 62 is a path for guiding the refrigerant from the second auxiliary path 60 to the compressor 4. 2 A fourth refrigerant control valve 72 is arranged in the second return path 62. 2 A motor 72a for adjusting the opening degree of the fourth refrigerant control valve 72 is electrically connected to the control means 16. 2 Then, the opening degree of the fourth refrigerant control valve 72 is adjusted by the motor 72a based on instructions from the control means 16. ​​​​

[0048] (Control means 16) The control means 16 is composed of a computer having a processor and a memory. The control means 16, based on an instruction input by an operator (for example, the temperature of the functional water used in the processing device 36), sets the pressure and temperature of the CO 2 refrigerant. Further, the control means 16 controls the rotational speed of the compressor 4 and the opening degree of the variable expansion valve 24 so that the actual temperature of the functional water becomes the set temperature (the temperature input by the operator), and further controls which of the first flow path 10 or the second flow path 12 to guide the CO 2 refrigerant to, etc.

[0049] (Operation of the temperature control device 2) Hereinafter, the operation of the above-described temperature control device 2 will be described. First, the case of heating the functional water will be described, and then the case of cooling the functional water will be described.

[0050] (When heating the functional water) In the description of heating the functional water, first, the operation of the basic temperature control device 2 will be described, and then the operation when increasing or decreasing the heating amount of the functional water will be described.

[0051] (Basic operation) In the temperature control device 2, when an operation instruction is input to the control means 16 by an operator, the control means 16 sets the value (set value) to be detected by each sensor according to the input operation instruction. Specifically, the control means 16 sets the set temperature of the functional water and the set pressure of the CO 2 refrigerant. The set temperature of the functional water is the temperature input by the operator. The set pressure of the CO 2 refrigerant is determined by the control means 16 based on the set temperature of the functional water.

[0052] (Set temperature of the functional water: First and second temperatures) The control means 16 sets, as the set temperature of the functional water, the first temperature to be detected by the first temperature sensor 38 or the second temperature to be detected by the second temperature sensor 40. The first temperature is the set temperature of the functional water flowing into the first heat exchanger 20. On the other hand, the second temperature is the set temperature of the functional water flowing out of the first heat exchanger 20. For example, the first temperature can be set to 20°C and the second temperature can be set to 23°C. When the functional water is disposable, the second temperature is set. That is, when the functional water from the functional water supply source 34 is heated to a predetermined temperature and sent to the processing device 36 and the functional water used in the processing device 36 is not returned to the functional water supply source 34, the second temperature is set. On the other hand, when the functional water (waste water) used in the processing device 36 is returned to the functional water supply source 34, the first temperature or the second temperature can be set.

[0053] (CO 2 Set pressure of the refrigerant: (first and second pressure values) The control means 16 sets, as the set pressure of the CO 2 refrigerant, the first pressure value to be detected by the first pressure sensor 6. The first pressure value is the CO 2 refrigerant (compressed CO 2 refrigerant) flowing out of the compressor 4. The first pressure value is set to a pressure (for example, about 10 MPa (absolute pressure)) exceeding the critical pressure of 7.38 MPa (absolute pressure) at which the CO 2 refrigerant becomes supercritical. Further, the control means 16 may set, as the set pressure of the CO 2 refrigerant, the second pressure value to be detected by the second pressure sensor 8. The second pressure value is the CO 2 refrigerant (uncompressed CO 2 refrigerant) flowing into the compressor 4. The second pressure value may be, for example, about 4 MPa (absolute pressure).

[0054] After the control means 16 sets the set temperature of the functional water and the set pressure of the CO 2 refrigerant, it compares the actual temperature of the functional water with the set temperature and determines whether to heat or cool the functional water. When the actual temperature of the functional water is lower than the set temperature, the control means 16 adopts the first path 10 to heat the functional water.

[0055] When the control means 16 heats the functional water by adopting the first path 10, the first and third CO 2 refrigerant control valves 18 and 56 are fully opened, and the second and fourth CO 2 refrigerant control valves 58 and 72 are fully closed. Further, when the control means 16 guides the CO 2 refrigerant to the first path 10, the fourth on-off valve 66 is opened, the fifth on-off valve 68 and the sixth on-off valve 70 are closed, the first on-off valve 50 is closed, and the second on-off valve 52 and the third on-off valve 54 are opened.

[0056] (CO 2 (Refrigerant flow) As shown by the thick-line arrow in FIG. 2, the CO 2 refrigerant flowing out from the compressor 4 passes through the first CO 2 refrigerant control valve 18, the fourth on-off valve 66, the refrigerant passage 20a of the first heat exchanger 20, the main passage 22a of the first internal heat exchanger 22, the variable expansion valve 24, the main passage 26a of the second internal heat exchanger 26, the refrigerant passage 28a of the second heat exchanger 28, the second on-off valve 52, the sub-passage 22b of the first internal heat exchanger 22, the third on-off valve 54, and the third CO 2 refrigerant control valve 56 in sequence.

[0057] CO 2 The operation in each device will be described together with the flow of the refrigerant. When heating the functional water by adopting the first path 10, the high-temperature and high-pressure CO 2 refrigerant compressed by the compressor 4 passes through the first CO 2 refrigerant control valve 18 and the fourth on-off valve 66 and flows into the refrigerant passage 20a of the first heat exchanger 20. In the first heat exchanger 20, heat exchange is performed between the CO 2 refrigerant in the refrigerant passage 20a and the functional water in the functional water passage 20b, and heat is given from the CO 2 refrigerant to the functional water. That is, the first heat exchanger 20 functions as a gas cooler, and the functional water is heated by the high-temperature CO 2 refrigerant.

[0058] Next, the CO 2The refrigerant flows into the main passage 22a of the first internal heat exchanger 22. The CO that has flowed into the main passage 22a 2 The refrigerant passes through the sub-passage 22b. The CO 2 After giving heat to the refrigerant, it flows into the variable expansion valve 24. In the variable expansion valve 24, the CO 2 The refrigerant is expanded, and the CO 2 The pressure and temperature of the refrigerant decrease.

[0059] Next, the CO that has passed through the variable expansion valve 24 2 The refrigerant passes through the main passage 26a of the second internal heat exchanger 26 and then flows into the refrigerant passage 28a of the second heat exchanger 28. In the second heat exchanger 28, the CO in the refrigerant passage 28a 2 Heat exchange occurs between the refrigerant and the industrial water in the industrial water passage 28b, and the CO 2 The refrigerant takes heat from the industrial water. That is, the second heat exchanger 28 functions as an evaporator, and the CO 2 The refrigerant takes heat from the industrial water and vaporizes. However, for the CO that has passed through the second heat exchanger 28 2 Liquid may remain in a part of the refrigerant.

[0060] Next, the CO that has passed through the second heat exchanger 28 2 The refrigerant passes through the second on-off valve 52 and then through the first auxiliary passage 30 and flows into the sub-passage 22b of the first internal heat exchanger 22. The CO that has flowed into the sub-passage 22b 2 The refrigerant passes through the main passage 22a. The CO 2 Takes heat from the refrigerant. Therefore, for the CO that has passed through the second heat exchanger 28 2 Even if liquid remains in the refrigerant, in the sub-passage 22b of the first internal heat exchanger 22, the CO 2 All the liquid in the refrigerant becomes gas. Therefore, the CO 2 All the refrigerant sucked into the compressor 4 becomes gas, so the load on the compressor 4 is reduced.

[0061] And the CO that has passed through the sub-passage 22b of the first internal heat exchanger 22 2 The refrigerant passes through the third on-off valve 54 of the first auxiliary passage 30 and the third CO of the first return passage 32 2It is sucked into the compressor 4 after passing through the refrigerant control valve 56.

[0062] In this way, when the control means 16 heats the functional water by adopting the first flow path 10, the first heat exchanger 20 functions as a gas cooler, and CO 2 The functional water is heated by the refrigerant. Further, the control means 16 causes the second heat exchanger 28 to function as an evaporator, and CO 2 The refrigerant takes heat from the industrial water. Furthermore, the control means 16 allows the CO 2 The refrigerant that has flowed out of the first heat exchanger 20 passes through the first internal heat exchanger 22, and the CO 2 Heat is given to the refrigerant that has flowed out of the second heat exchanger 28, and the CO 2 The liquid CO 2 remaining in the refrigerant is vaporized to reduce the load on the compressor 4. That is, in the present embodiment, since the CO 2 The refrigerant is completely vaporized, the problem of compressing the liquid CO 2 refrigerant and shortening the life of the compressor 4 is solved.

[0063] (Improvement of coefficient of performance) When the control means 16 of the present embodiment heats the functional water by adopting the first flow path 10, in addition to increasing or decreasing the heating amount of the functional water by increasing or decreasing the rotational speed of the compressor 4 so that the temperature of the first temperature sensor 38 or the second temperature sensor 40 becomes a predetermined temperature, the coefficient of performance is increased by changing the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 becomes a predetermined pressure value.

[0064] (Rotational speed of compressor 4) The control means 16 adjusts the heating amount of the functional water by increasing or decreasing the rotational speed of the compressor 4. When the rotational speed of the compressor 4 is increased, the amount of the high-temperature CO 2 refrigerant compressed by the compressor 4 flowing into the first heat exchanger 20 increases, so the heating amount of the functional water increases. On the contrary, when the rotational speed of the compressor 4 is decreased, the high-temperature CO 2Since the amount of refrigerant flowing into the first heat exchanger 20 decreases, the heating amount of the functional water decreases.

[0065] (Opening degree of the variable expansion valve 24) The control means 16 adjusts the detected value of the first pressure sensor 6 by changing the opening degree of the variable expansion valve 24. When the opening degree of the variable expansion valve 24 is increased, the CO passing through the variable expansion valve 24 2 Since the refrigerant flow rate increases, the detected value of the first pressure sensor 6 decreases. On the other hand, when the opening degree of the variable expansion valve 24 is decreased, the CO passing through the variable expansion valve 24 2 Since the refrigerant flow rate decreases, the detected value of the first pressure sensor 6 increases.

[0066] (Coefficient of performance) The coefficient of performance is a measure of energy consumption efficiency and can be defined as the heating capacity divided by the compression work (coefficient of performance = heating capacity / compression work). The heating capacity is the ability of the CO refrigerant in the first heat exchanger 20 to heat the functional water. The compression work is the work performed by the compressor 4, that is, the power consumed by the motor 4a of the compressor 4. 2 The compression work is the work performed by the compressor 4, that is, the power consumed by the motor 4a of the compressor 4.

[0067] The control means 16 determines the required heating capacity based on the first temperature or the second temperature, and adjusts the rotation speed of the compressor 4 and the opening degree of the variable expansion valve 24 so as to satisfy this heating capacity, thereby controlling the temperature and pressure of the CO refrigerant. At this time, the control means 16 sets the rotation speed of the compressor 4 to the minimum required rotation speed (that is, makes the compression work as small as possible) to increase the coefficient of performance. Therefore, the coefficient of performance in the temperature control device 2 will be much higher than the coefficient of performance 1 of the electric heater. 2 The control means 16 of the present embodiment controls the water control valve 44 so that the temperature difference between the temperature of the third temperature sensor 46 and the temperature of the fourth temperature sensor 48 becomes constant, thereby suppressing waste of industrial water. That is, the control means 16 controls the opening degree of the water control valve 44 to appropriately maintain the heat exchange capacity of the second heat exchanger 28.

[0068] (Suppression of waste of industrial water) The control means 16 of the present embodiment controls the water control valve 44 so that the temperature difference between the temperature of the third temperature sensor 46 and the temperature of the fourth temperature sensor 48 becomes constant, thereby suppressing waste of industrial water. That is, the control means 16 controls the opening degree of the water control valve 44 to appropriately maintain the heat exchange capacity of the second heat exchanger 28.

[0069] (When increasing the opening degree of the water control valve 44) When increasing the opening degree of the water control valve 44 means increasing the rotational speed of the compressor 4. When the rotational speed of the compressor 4 is increased, the CO 2 refrigerant flow rate increases in the second heat exchanger 28. Then, the amount of heat taken from the industrial water by the CO 2 refrigerant increases in the second heat exchanger 28, so the temperature difference between the temperature of the third temperature sensor 46 and the temperature of the fourth temperature sensor 48 increases. In such a case, the control means 16 increases the opening degree of the water control valve 44 so that the temperature difference between the temperature of the third temperature sensor 46 and the temperature of the fourth temperature sensor 48 becomes constant, thereby suppressing waste of industrial water.

[0070] (When decreasing the opening degree of the water control valve 44) On the other hand, when decreasing the opening degree of the water control valve 44 means decreasing the rotational speed of the compressor 4. When the rotational speed of the compressor 4 is decreased, the CO 2 refrigerant flow rate decreases in the second heat exchanger 28. Then, the amount of heat taken from the industrial water by the CO 2 refrigerant decreases in the second heat exchanger 28, so the temperature difference between the temperature of the third temperature sensor 46 and the temperature of the fourth temperature sensor 48 decreases. In such a case, the control means 16 decreases the opening degree of the water control valve 44 so that the temperature difference between the temperature of the third temperature sensor 46 and the temperature of the fourth temperature sensor 48 becomes constant, thereby suppressing waste of industrial water.

[0071] Next, the operation of the temperature control device 2 when increasing or decreasing the heating amount of the functional water (that is, when changing the set temperature of the functional water) will be described.

[0072] (When increasing the heating amount of the functional water) First, the case of increasing the heating amount of the functional water (raising the set temperature of the functional water) will be described. In this case, the control means 16 increases the rotational speed of the compressor 4. As a result, the high-temperature CO compressed by the compressor 4 2Since the amount of the refrigerant flowing into the first heat exchanger 20 increases, the heating amount of the functional water increases. However, when the flow rate of the CO 2 refrigerant is increased, the detected value of the first pressure sensor 6 may exceed the first pressure value. Therefore, the control means 16 appropriately increases the opening degree of the variable expansion valve 24 according to the increase range of the set temperature of the functional water. Thereby, the detected value of the first pressure sensor 6 can be maintained at the first pressure value. Therefore, in the temperature control device 2, even if the heating amount of the functional water is increased, the discharge pressure of the compressor 4 does not fluctuate greatly, so that highly efficient heating control can be realized.

[0073] (When reducing the heating amount of the functional water) On the other hand, when reducing the heating amount of the functional water (when lowering the set temperature of the functional water), the control means 16 reduces the rotational speed of the compressor 4. As a result, the amount of the high-temperature CO 2 refrigerant compressed by the compressor 4 flowing into the first heat exchanger 20 decreases, so that the heating amount of the functional water decreases.

[0074] In this case, there are times when the temperature of the functional water does not drop to the set temperature even though the rotational speed of the compressor 4 has reached the minimum rotational speed. In such a case, when the rotational speed of the compressor 4 reaches the minimum rotational speed, the control means 16 gradually increases the opening degree of the second CO 2 refrigerant control valve 58 from fully closed, and as shown by the dotted arrow in FIG. 3, a part of the CO 2 refrigerant flowing out of the compressor 4 is made to flow toward the second CO 2 refrigerant control valve 58. That is, the flow rate of the CO 2 refrigerant in the first heat exchanger 20 is further reduced, and the heating amount of the functional water is further reduced. As a result, the temperature of the functional water can be lowered to the set temperature without reducing the rotational speed of the compressor 4 below the minimum rotational speed.

[0075] However, the second CO 2When the opening degree of the refrigerant control valve 58 is increased, the detected value of the second pressure sensor 8 increases, and the detected value of the first pressure sensor 6 decreases. In this case, there is a possibility that the detected value of the first pressure sensor 6 may fall significantly below the first pressure value (set value). Therefore, the control means 16 appropriately reduces the opening degree of the variable expansion valve 24 according to the decrease width of the set temperature of the functional water. Thereby, the detected value of the first pressure sensor 6 can be maintained at a predetermined pressure value (the first pressure value).

[0076] Also, the second CO 2 Even when the opening degree of the refrigerant control valve 58 reaches the maximum opening degree, there are times when the temperature of the functional water does not drop to the set temperature. In such a case, the control means 16 is the second CO 2 When the opening degree of the refrigerant control valve 58 reaches the maximum opening degree, subsequently the fourth CO 2 Gradually increase the opening degree of the refrigerant control valve 72 from fully closed. As a result, as shown by the dotted arrow in Fig. 4, a part of the CO 2 refrigerant flowing out from the compressor 4 is made to pass not only through the second CO 2 refrigerant control valve 58 but also through the fourth CO 2 refrigerant control valve 72. That is, the flow rate of the CO 2 refrigerant in the first heat exchanger 20 is further reduced, and the heating amount of the functional water is decreased. As a result, the temperature of the functional water can be lowered to the set temperature.

[0077] However, the second CO 2 Not only the refrigerant control valve 58 but also the fourth CO 2 When the opening degree of the refrigerant control valve 72 is increased, the detected value of the second pressure sensor 8 increases, and the detected value of the first pressure sensor 6 decreases. In this case, there is a possibility that the detected value of the first pressure sensor 6 may fall significantly below the first pressure value. Therefore, the control means 16 further reduces the opening degree of the variable expansion valve 24 according to the decrease width of the set temperature of the functional water. Thereby, the detected value of the first pressure sensor 6 can be maintained at a predetermined pressure value (the first pressure value).

[0078] Thus, when the control means 16 reduces the heating amount of the functional water, it decreases the rotational speed of the compressor 4. When the rotational speed of the compressor 4 reaches the minimum rotational speed, in order to further reduce the heating amount, the second CO 2 increases the opening degree of the refrigerant control valve 58 gradually from fully closed, and the second CO 2 by increasing the opening degree of the refrigerant control valve 58, raises the detected value of the second pressure sensor 8. At this time, the opening degree of the variable expansion valve 24 is decreased so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value, and the second CO 2 when the opening degree of the refrigerant control valve 58 reaches the maximum opening degree, subsequently the fourth CO 2 increases the opening degree of the refrigerant control valve 72 gradually from fully closed, and further decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value. Thus, in the temperature control device 2, even when the set temperature of the functional water is decreased, the discharge pressure of the compressor 4 does not fluctuate significantly, so that highly efficient heating control can be realized.

[0079] (When the heating amount of the functional water is set to 0) When the control means 16 sets the heating amount of the functional water to 0 (when stopping the heating of the functional water), first, it gradually decreases the rotational speed of the compressor 4. Also, it decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value.

[0080] When the rotational speed of the compressor 4 reaches the minimum rotational speed, the control means 16 gradually increases the opening degree of the second CO 2 refrigerant control valve 58 from fully closed. Also, it further decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value.

[0081] The second CO 2 when the opening degree of the refrigerant control valve 58 reaches the maximum opening degree, the control means 16 subsequently gradually increases the opening degree of the fourth CO 2 refrigerant control valve 72 from fully closed. Also, it further decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value and finally closes it completely.

[0082] As a result, CO 2 The refrigerant stops circulating. That is, as shown by the thick arrow in FIG. 5, the CO 2 The refrigerant does not pass through the first and second heat exchangers 20, 28 and the first and second internal heat exchangers 22, 26, but is mixed with the first to fourth CO 2 The functional water passes through the refrigerant control valves 18, 58, 56, and 72. Therefore, the functional water is neither heated nor cooled.

[0083] (When cooling functional water) Next, the case of cooling the functional water will be described. In the explanation of cooling the functional water, first, the basic operation of the temperature control device 2 will be described, and then the operation in the case of increasing or decreasing the cooling amount of the functional water will be described.

[0084] (Basic operation) In the temperature control device 2, when cooling the functional water, as in the case of heating the functional water, when an operation command is input to the control means 16 by an operator, the control means 16 sets the values ​​(set values) to be detected by each sensor in accordance with the input operation command. 2 The set pressure of the refrigerant is set by the control means 16. The set temperature of the functional water is the temperature input by the operator. 2 The set pressure of the refrigerant is determined by the control means 16 based on the set temperature of the functional water.

[0085] (Functional water temperature settings: first and second temperatures) The control means 16 sets, as the set temperature of the functional water, the first temperature to be detected by the first temperature sensor 38 or the second temperature to be detected by the second temperature sensor 40. For example, the first temperature can be set to 23°C and the second temperature can be set to 20°C. When the functional water is disposable, the second temperature is set. That is, when the functional water from the functional water supply source 34 is cooled to a predetermined temperature and sent to the processing device 36, and the functional water used in the processing device 36 is not returned to the functional water supply source 34, the second temperature is set. On the other hand, when the functional water (waste water) used in the processing device 36 is returned to the functional water supply source 34, the first temperature or the second temperature can be set.

[0086] (CO 2 Set pressure of refrigerant: (First and second pressure values) Even when the control means 16 cools the functional water, CO 2 sets, as the set pressure of the refrigerant, the first pressure value to be detected by the first pressure sensor 6. The first pressure value is a pressure (for example, about 10 MPa (absolute pressure)) exceeding the critical pressure 7.38 MPa (absolute pressure) at which the CO of the refrigerant 2 becomes supercritical. Further, the control means 16 may set, as the set pressure of the refrigerant, the second pressure value to be detected by the second pressure sensor 8. The second pressure value may be, for example, about 4 MPa (absolute pressure). 2

[0087] After setting the set temperature of the functional water and the set pressure of the CO 2 refrigerant, the control means 16 compares the actual temperature of the functional water with the set temperature and determines whether to heat or cool the functional water. When the actual temperature of the functional water is higher than the set temperature, the control means 16 adopts the second bypass 12 to cool the functional water.

[0088] When the control means 16 adopts the second bypass 12 to cool the functional water, the second and fourth CO 2 refrigerant control valves 58 and 72 are fully opened, and the first and third CO 2 refrigerant control valves 18 and 56 are fully closed. Further, the control means 16 supplies CO to the second bypass 12 2 ​When guiding the refrigerant, open the first on-off valve 50, close the second on-off valve 52 and the third on-off valve 54, close the fourth on-off valve 66, and open the fifth on-off valve 68 and the sixth on-off valve 70.

[0089] (CO 2 (Refrigerant flow) As shown by the thick solid arrow in FIG. 6, the CO 2 refrigerant flowing out from the compressor 4 passes through the second CO 2 refrigerant control valve 58, the first on-off valve 50, the refrigerant passage 28a of the second heat exchanger 28, the main passage 26a of the second internal heat exchanger 26, the variable expansion valve 24, the main passage 22a of the first internal heat exchanger 22, the refrigerant passage 20a of the first heat exchanger 20, the fifth on-off valve 68, the sub-passage 26b of the second internal heat exchanger 26, the sixth on-off valve 70, and the fourth CO 2 refrigerant control valve 72 in sequence.

[0090] CO 2 The operation of each device along with the CO 2 refrigerant flow will be described. When cooling the functional water by adopting the second bypass 12, the high-temperature and high-pressure CO 2 refrigerant compressed by the compressor 4 passes through the second CO 2 refrigerant control valve 58 and the first on-off valve 50 and then flows into the refrigerant passage 28a of the second heat exchanger 28. In the second heat exchanger 28, heat exchange occurs between the CO 2 refrigerant in the refrigerant passage 28a and the functional water in the industrial water passage 28b, and the industrial water takes heat away from the CO 2 refrigerant. That is, the second heat exchanger 28 functions as a gas cooler and gives heat from the high-temperature CO

[0091] Next, the CO 2 refrigerant passing through the second heat exchanger 28 flows into the main passage 26a of the second internal heat exchanger 26. The CO 2 refrigerant flowing into the main passage 26a gives heat to the CO 2 refrigerant passing through the sub-passage 26b and then flows into the variable expansion valve 24. In the variable expansion valve 24, the CO 2 refrigerant is expanded, and the pressure and temperature of the CO 2 refrigerant decrease.

[0092] Next, the CO that has passed through the variable expansion valve 24 2 The refrigerant flows into the refrigerant passage 20a of the first heat exchanger 20 after passing through the main passage 22a of the first internal heat exchanger 22. In the first heat exchanger 20, the CO in the refrigerant passage 20a 2 Heat exchange takes place between the refrigerant and the functional water in the functional water passage 20b, and the CO 2 The refrigerant takes heat from the functional water. That is, the first heat exchanger 20 functions as an evaporator, and the CO 2 The refrigerant takes heat from the functional water and vaporizes. However, the CO that has passed through the first heat exchanger 20 2 Liquid may remain in a part of the refrigerant.

[0093] Next, the CO that has passed through the first heat exchanger 20 2 The refrigerant flows into the sub-passage 26b of the second internal heat exchanger 26 after passing through the fifth on-off valve 68 and then through the second auxiliary passage 60. The CO that has flowed into the sub-passage 26b 2 The refrigerant takes heat from the CO passing through the main passage 26a 2 For this reason, even if liquid remains in the CO that has passed through the first heat exchanger 20, in the sub-passage 26b of the second internal heat exchanger 26, the CO 2 All the liquid in the refrigerant becomes gas. Therefore, all of the CO sucked into the compressor 4 2 becomes gas, reducing the load on the compressor 4. 2 Since all of the refrigerant becomes gas, the load on the compressor 4 is reduced.

[0094] And the CO that has passed through the sub-passage 26b of the second internal heat exchanger 26 2 The refrigerant passes through the sixth on-off valve 70 of the second auxiliary passage 60 and the fourth CO 2 refrigerant control valve 72 of the second return passage 62 and is sucked into the compressor 4.

[0095] In this way, when the control means 16 cools the functional water by adopting the second forward path 12, the second heat exchanger 28 functions as a gas cooler, and the CO is cooled by industrial water 2Cause the refrigerant to absorb heat. Further, the control means 16 causes the first heat exchanger 20 to function as an evaporator, and causes the CO 2 refrigerant to absorb heat from the functional water (CO 2 refrigerant to cool the functional water). Further, the control means 16 allows the CO 2 refrigerant flowing out of the second heat exchanger 28 to pass through the second internal heat exchanger 26 and gives heat to the CO 2 refrigerant flowing out of the first heat exchanger 20, and vaporizes the liquid CO 2 refrigerant remaining in the refrigerant flowing out of the first heat exchanger 20, 2 thereby reducing the load on the compressor 4. That is, in the present embodiment, even when cooling the functional water, since the CO 2 refrigerant fed into the compressor 4 is completely vaporized, the problem of compressing the liquid CO 2 refrigerant and shortening the life of the compressor 4 is solved.

[0096] (Improvement of cooling efficiency) When the control means 16 of the present embodiment cools the functional water by adopting the second bypass 12, in addition to increasing or decreasing the rotation speed of the compressor 4 so that the temperature of the first temperature sensor 38 or the second temperature sensor 40 becomes a predetermined temperature and increasing or decreasing the cooling amount of the functional water, the cooling efficiency is increased by changing the opening degree of the variable expansion valve 24 so that the detection value of the first pressure sensor 6 becomes a predetermined pressure value.

[0097] (Rotation speed of the compressor 4) The control means 16 adjusts the cooling amount of the functional water by increasing or decreasing the rotation speed of the compressor 4. When the rotation speed of the compressor 4 is increased, the amount of the low-temperature CO 2 refrigerant expanded by the variable expansion valve 24 flowing into the first heat exchanger 20 increases, so the cooling amount of the functional water increases. Conversely, when the rotation speed of the compressor 4 is decreased, the amount of the low-temperature CO 2 refrigerant expanded by the variable expansion valve 24 flowing into the first heat exchanger 20 decreases, so the cooling amount of the functional water decreases.

[0098] (Opening degree of the variable expansion valve 24) The control means 16 adjusts the detected value of the first pressure sensor 6 by changing the opening degree of the variable expansion valve 24. When the opening degree of the variable expansion valve 24 is increased, the flow rate of the CO 2 refrigerant passing through the variable expansion valve 24 increases, so the detected value of the first pressure sensor 6 decreases. On the other hand, when the opening degree of the variable expansion valve 24 is decreased, the flow rate of the CO 2 refrigerant passing through the variable expansion valve 24 decreases, so the detected value of the first pressure sensor 6 increases.

[0099] (Cooling efficiency) Cooling efficiency is a measure of energy consumption efficiency and can be defined as the cooling capacity divided by the compression work (cooling efficiency = cooling capacity / compression work). The cooling capacity is the ability of the CO 2 refrigerant to cool the functional water in the first heat exchanger 20. The compression work is the work performed by the compressor 4, that is, the power consumed by the motor 4a of the compressor 4.

[0100] The control means 16 determines the required cooling capacity based on the first temperature or the second temperature, and adjusts the rotational speed of the compressor 4 and the opening degree of the variable expansion valve 24 so as to satisfy this cooling capacity, and controls the temperature and pressure of the CO 2 refrigerant. At this time, the control means 16 increases the cooling efficiency by setting the rotational speed of the compressor 4 to the minimum required rotational speed (that is, making the compression work as small as possible).

[0101] (Adjustment of the flow rate of industrial water) The control means 16 of the present embodiment controls the water control valve 44 based on the temperature of the third temperature sensor 46 that detects the temperature of the industrial water flowing into the second heat exchanger 28 so that the temperature of the fifth temperature sensor 64 that detects the temperature of the CO 2 refrigerant flowing out of the second heat exchanger 28 becomes a predetermined temperature, and adjusts the amount of industrial water flowing into the second heat exchanger 28.

[0102] When the opening degree of the water control valve 44 increases, the amount of industrial water flowing into the second heat exchanger 28 increases, so the CO 2The cooling of the refrigerant is promoted. On the other hand, when the opening degree of the water control valve 44 becomes small, the amount of industrial water flowing into the second heat exchanger 28 decreases, so the CO 2 The cooling of the refrigerant is suppressed.

[0103] And the control means 16 controls the opening degree of the water control valve 44 based on the temperature of the third temperature sensor 46, and adjusts the amount of industrial water flowing into the second heat exchanger 28. As a result, the CO 2 The temperature of the refrigerant is set to a predetermined temperature. As a result, in the second internal heat exchanger 26, the CO 2 Refrigerant can give the required heat to the CO 2 Refrigerant flowing out of the first heat exchanger 20. Therefore, the liquid CO 2 Remaining in the refrigerant flowing out of the first heat exchanger 20 2 Refrigerant is surely vaporized, and the load on the compressor 4 is reduced.

[0104] Next, the operation of the temperature control device 2 when increasing or decreasing the cooling amount of the functional water (that is, when changing the set temperature of the functional water) will be described.

[0105] (When increasing the cooling amount of the functional water) First, the case of increasing the cooling amount of the functional water (the case of lowering the set temperature of the functional water) will be described. In this case, the control means 16 increases the rotational speed of the compressor 4. As a result, the amount of the low-temperature CO 2 Refrigerant flowing into the first heat exchanger 20 increases, so the cooling amount of the functional water increases. However, the CO 2When the flow rate of the refrigerant increases, the detected value of the first pressure sensor 6 may exceed the first pressure value. Therefore, the control means 16 appropriately increases the opening degree of the variable expansion valve 24 according to the decrease width of the set temperature of the functional water. As a result, the detected value of the first pressure sensor 6 can be maintained at the first pressure value. Therefore, in the temperature control device 2, even if the cooling capacity of the functional water is increased, the discharge pressure of the compressor 4 does not fluctuate greatly, so that highly efficient cooling control can be realized.

[0106] (When reducing the cooling capacity of the functional water) On the other hand, when reducing the cooling capacity of the functional water (when raising the set temperature of the functional water), the control means 16 reduces the rotational speed of the compressor 4. As a result, the amount of the low-temperature CO 2 refrigerant expanded by the variable expansion valve 24 flowing into the first heat exchanger 20 decreases, so that the cooling capacity of the functional water decreases.

[0107] In this case, there are times when the temperature of the functional water does not rise to the set temperature even though the rotational speed of the compressor 4 has reached the minimum rotational speed. In such a case, when the rotational speed of the compressor 4 reaches the minimum rotational speed, the control means 16 gradually increases the opening degree of the first CO 2 refrigerant control valve 18 from fully closed, and as shown by the dotted arrow in FIG. 7, a part of the CO 2 refrigerant flowing out of the compressor 4 is made to flow toward the first CO 2 refrigerant control valve 18. That is, the flow rate of the CO 2 refrigerant in the first heat exchanger 20 is further reduced, and the cooling capacity of the functional water is further reduced. As a result, the temperature of the functional water can be raised to the set temperature without reducing the rotational speed of the compressor 4 below the minimum rotational speed.

[0108] However, the first CO 2When the opening degree of the refrigerant control valve 18 is increased, the detected value of the second pressure sensor 8 increases and the detected value of the first pressure sensor 6 decreases. In this case, there is a possibility that the detected value of the first pressure sensor 6 may fall significantly below the first pressure value. Therefore, the control means 16 appropriately reduces the opening degree of the variable expansion valve 24 according to the increase range of the set temperature of the functional water. Thereby, the detected value of the first pressure sensor 6 can be maintained at a predetermined pressure value (first pressure value).

[0109] Also, the first CO 2 Even when the opening degree of the refrigerant control valve 18 reaches the maximum opening degree, there are times when the temperature of the functional water does not drop to the set temperature. In such a case, the control means 16 is the first CO 2 When the opening degree of the refrigerant control valve 18 reaches the maximum opening degree, subsequently the third CO 2 Gradually increase the opening degree of the refrigerant control valve 56 from fully closed. As a result, as shown by the dotted arrow in FIG. 8, a part of the CO 2 refrigerant flowing out from the compressor 4 is passed not only through the first CO 2 refrigerant control valve 18 but also through the third CO 2 refrigerant control valve 56. That is, the flow rate of the CO 2 refrigerant in the first heat exchanger 20 is further reduced, and the cooling capacity of the functional water is decreased. As a result, the temperature of the functional water can be raised to the set temperature.

[0110] However, the first CO 2 Not only the first refrigerant control valve 18 but also the third CO 2 When the opening degree of the refrigerant control valve 56 is increased, the detected value of the second pressure sensor 8 increases and the detected value of the first pressure sensor 6 decreases. In this case, there is a possibility that the detected value of the first pressure sensor 6 may fall significantly below the first pressure value (set value). Therefore, the control means 16 further reduces the opening degree of the variable expansion valve 24 according to the increase range of the set temperature of the functional water. Thereby, the detected value of the first pressure sensor 6 can be maintained at a predetermined pressure value (first pressure value).

[0111] Thus, when the control means 16 reduces the cooling capacity of the functional water, it decreases the rotational speed of the compressor 4. When the rotational speed of the compressor 4 reaches the minimum rotational speed, in order to further reduce the cooling capacity, the first CO 2 increases the opening degree of the refrigerant control valve 18 gradually from fully closed, and the first CO 2 by increasing the opening degree of the refrigerant control valve 18, raises the detected value of the second pressure sensor 8. At this time, the opening degree of the variable expansion valve 24 is decreased so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value, and the first CO 2 when the opening degree of the refrigerant control valve 18 reaches the maximum opening degree, subsequently the third CO 2 increases the opening degree of the refrigerant control valve 56 gradually from fully closed, and further decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value. As a result, in the temperature control device 2, even when the set temperature of the functional water is decreased, the discharge pressure of the compressor 4 does not fluctuate significantly, so that highly efficient cooling control can be realized.

[0112] (When the cooling capacity of the functional water is set to 0) When the control means 16 sets the cooling capacity of the functional water to 0 (when stopping the cooling of the functional water), first, it gradually decreases the rotational speed of the compressor 4. Also, it decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value.

[0113] When the rotational speed of the compressor 4 reaches the minimum rotational speed, the control means 16 gradually increases the opening degree of the first CO 2 refrigerant control valve 18 from fully closed. Also, it further decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value.

[0114] The first CO 2 when the opening degree of the refrigerant control valve 18 reaches the maximum opening degree, the control means 16 subsequently gradually increases the opening degree of the third CO 2 refrigerant control valve 56 from fully closed. Also, it further decreases the opening degree of the variable expansion valve 24 so that the detected value of the first pressure sensor 6 is maintained at a predetermined pressure value and finally closes it completely.

[0115] As a result, the CO refrigerant stops circulating in the first flow path 10 and the second flow path 12. That is, as shown by the thick arrow in Fig. 5, the CO refrigerant flowing out of the compressor 4 does not pass through the first and second heat exchangers 20 and 28, and the first and second internal heat exchangers 22 and 26, but passes through the first to fourth CO refrigerant control valves 18, 58, 56, and 72. Therefore, the functional water is neither heated nor cooled. 2 As a result, the CO refrigerant stops circulating in the first flow path 10 and the second flow path 12. That is, as shown by the thick arrow in Fig. 5, the CO refrigerant flowing out of the compressor 4 does not pass through the first and second heat exchangers 20 and 28, and the first and second internal heat exchangers 22 and 26, but passes through the first to fourth CO refrigerant control valves 18, 58, 56, and 72. Therefore, the functional water is neither heated nor cooled. 2 As a result, the CO refrigerant stops circulating in the first flow path 10 and the second flow path 12. That is, as shown by the thick arrow in Fig. 5, the CO refrigerant flowing out of the compressor 4 does not pass through the first and second heat exchangers 20 and 28, and the first and second internal heat exchangers 22 and 26, but passes through the first to fourth CO refrigerant control valves 18, 58, 56, and 72. Therefore, the functional water is neither heated nor cooled. 2 As a result, the CO refrigerant stops circulating in the first flow path 10 and the second flow path 12. That is, as shown by the thick arrow in Fig. 5, the CO refrigerant flowing out of the compressor 4 does not pass through the first and second heat exchangers 20 and 28, and the first and second internal heat exchangers 22 and 26, but passes through the first to fourth CO refrigerant control valves 18, 58, 56, and 72. Therefore, the functional water is neither heated nor cooled.

[0116] Finally, the cases of shifting from the state of heating the functional water to the state of cooling it and from the state of cooling the functional water to the state of heating it will be described.

[0117] (Shift from heating to cooling) When shifting from the state of heating the functional water to the state of cooling it, the control means 16 sequentially shifts to the state shown in Fig. 2 → the state shown in Fig. 3 → the state shown in Fig. 4 → the state shown in Fig. 5 → the state shown in Fig. 6.

[0118] That is, the control means 16 shifts from the state of heating the functional water by adopting the first flow path 10 (the state shown in Fig. 2), gradually reduces the rotational speed of the compressor 4 to the minimum rotational speed, and then shifts to the state where the opening degree of the second CO refrigerant control valve 58 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is decreased (the state shown in Fig. 3). Next, after the opening degree of the second CO refrigerant control valve 58 reaches the maximum opening degree, it subsequently shifts to the state where the opening degree of the fourth CO refrigerant control valve 72 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is further decreased (the state shown in Fig. 4). Then, the opening degree of the variable expansion valve 24 is further decreased to fully closed, and the CO refrigerant is not circulated in the first flow path 10 and the second flow path 12, and it shifts to the state where the functional water is neither heated nor cooled (the state shown in Fig. 5). And it shifts to the state of cooling the functional water by adopting the second flow path 12 (the state shown in Fig. 6). 2 That is, the control means 16 shifts from the state of heating the functional water by adopting the first flow path 10 (the state shown in Fig. 2), gradually reduces the rotational speed of the compressor 4 to the minimum rotational speed, and then shifts to the state where the opening degree of the second CO refrigerant control valve 58 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is decreased (the state shown in Fig. 3). Next, after the opening degree of the second CO refrigerant control valve 58 reaches the maximum opening degree, it subsequently shifts to the state where the opening degree of the fourth CO refrigerant control valve 72 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is further decreased (the state shown in Fig. 4). Then, the opening degree of the variable expansion valve 24 is further decreased to fully closed, and the CO refrigerant is not circulated in the first flow path 10 and the second flow path 12, and it shifts to the state where the functional water is neither heated nor cooled (the state shown in Fig. 5). And it shifts to the state of cooling the functional water by adopting the second flow path 12 (the state shown in Fig. 6). 2 That is, the control means 16 shifts from the state of heating the functional water by adopting the first flow path 10 (the state shown in Fig. 2), gradually reduces the rotational speed of the compressor 4 to the minimum rotational speed, and then shifts to the state where the opening degree of the second CO refrigerant control valve 58 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is decreased (the state shown in Fig. 3). Next, after the opening degree of the second CO refrigerant control valve 58 reaches the maximum opening degree, it subsequently shifts to the state where the opening degree of the fourth CO refrigerant control valve 72 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is further decreased (the state shown in Fig. 4). Then, the opening degree of the variable expansion valve 24 is further decreased to fully closed, and the CO refrigerant is not circulated in the first flow path 10 and the second flow path 12, and it shifts to the state where the functional water is neither heated nor cooled (the state shown in Fig. 5). And it shifts to the state of cooling the functional water by adopting the second flow path 12 (the state shown in Fig. 6). 2 That is, the control means 16 shifts from the state of heating the functional water by adopting the first flow path 10 (the state shown in Fig. 2), gradually reduces the rotational speed of the compressor 4 to the minimum rotational speed, and then shifts to the state where the opening degree of the second CO refrigerant control valve 58 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is decreased (the state shown in Fig. 3). Next, after the opening degree of the second CO refrigerant control valve 58 reaches the maximum opening degree, it subsequently shifts to the state where the opening degree of the fourth CO refrigerant control valve 72 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is further decreased (the state shown in Fig. 4). Then, the opening degree of the variable expansion valve 24 is further decreased to fully closed, and the CO refrigerant is not circulated in the first flow path 10 and the second flow path 12, and it shifts to the state where the functional water is neither heated nor cooled (the state shown in Fig. 5). And it shifts to the state of cooling the functional water by adopting the second flow path 12 (the state shown in Fig. 6). 2 That is, the control means 16 shifts from the state of heating the functional water by adopting the first flow path 10 (the state shown in Fig. 2), gradually reduces the rotational speed of the compressor 4 to the minimum rotational speed, and then shifts to the state where the opening degree of the second CO refrigerant control valve 58 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is decreased (the state shown in Fig. 3). Next, after the opening degree of the second CO refrigerant control valve 58 reaches the maximum opening degree, it subsequently shifts to the state where the opening degree of the fourth CO refrigerant control valve 72 is gradually increased from fully closed and the opening degree of the variable expansion valve 24 is further decreased (the state shown in Fig. 4). Then, the opening degree of the variable expansion valve 24 is further decreased to fully closed, and the CO refrigerant is not circulated in the first flow path 10 and the second flow path 12, and it shifts to the state where the functional water is neither heated nor cooled (the state shown in Fig. 5). And it shifts to the state of cooling the functional water by adopting the second flow path 12 (the state shown in Fig. 6).

[0119] In this way, the control means 16 gradually reduces the heating amount from the state of heating the functional water, and after setting the heating amount to 0, it shifts to the state of cooling the functional water. This prevents an excessive load from acting on the temperature control device 2.

[0120] (Transition from cooling to heating) On the other hand, when shifting from the state of cooling the functional water to the state of heating it, the control means 16 sequentially shifts to the state shown in FIG. 6 → the state shown in FIG. 7 → the state shown in FIG. 8 → the state shown in FIG. 5 → the state shown in FIG. 2.

[0121] That is, the control means 16 starts from the state of heating the functional water by adopting the second flow path 12 (the state shown in FIG. 6), gradually reduces the rotational speed of the compressor 4 to the minimum rotational speed, and then the first CO 2 while gradually increasing the opening degree of the refrigerant control valve 18 from fully closed and decreasing the opening degree of the variable expansion valve 24, it shifts to the state shown in FIG. 7. Next, the first CO 2 after the opening degree of the refrigerant control valve 18 reaches the maximum opening degree, subsequently the third CO 2 while gradually increasing the opening degree of the refrigerant control valve 56 from fully closed and further decreasing the opening degree of the variable expansion valve 24, it shifts to the state shown in FIG. 8. Next, the opening degree of the variable expansion valve 24 is further decreased to fully closed, and no CO 2 refrigerant is circulated through the first flow path 10 and the second flow path 12, and it shifts to the state of neither heating nor cooling the functional water (the state shown in FIG. 5). Then, it shifts to the state of heating the functional water by adopting the first flow path 10 (the state shown in FIG. 2).

[0122] In this way, the control means 16 gradually reduces the cooling amount from the state of cooling the functional water, and after setting the cooling amount to 0, it shifts to the state of heating the functional water. This prevents an excessive load from acting on the temperature control device 2.

[0123] As described above, since the temperature control device 2 includes the first and second internal heat exchangers 22 and 26, even if the water temperature of the functional water used in the processing device 36 is set low, the CO sent to the compressor 4 2Since the refrigerant is completely vaporized, the problem of compressing the liquid CO 2 refrigerant and shortening the life of the compressor 4 is solved. Further, the temperature control device 2 can control the pressure of the CO 2 refrigerant according to the operating conditions, so that highly efficient heating control and cooling control can be realized. Therefore, according to the temperature control device 2, it is possible to increase the coefficient of performance and the cooling efficiency while preventing liquid compression.

Explanation of Signs

[0124] 2: Temperature control device 4: Compressor 6: First pressure sensor 8: Second pressure sensor 10: First passage 12: Second passage 14: Branch portion 16: Control means 18: First CO 2 Refrigerant control valve 20: First heat exchanger 22: First internal heat exchanger 24: Variable expansion valve 26: Second internal heat exchanger 28: Second heat exchanger 30: First auxiliary path 32: First return path 38: First temperature sensor 40: Second temperature sensor 44: Water control valve 46: Third temperature sensor 48: Fourth temperature sensor 50: First on-off valve 52: Second on-off valve 54: Third on-off valve 56: Third CO 2 Refrigerant control valve 58: Second CO 2 Refrigerant control valve 60: Second auxiliary path 62: Second return path 64: Fifth temperature sensor 66: Fourth on-off valve 68: Fifth on-off valve 70: Sixth on-off valve 72: Fourth CO 2 Refrigerant control valve

Claims

1. A temperature control device for controlling the temperature of functional water by cooling or heating the functional water, comprising CO ２ A compressor that compresses a refrigerant, CO from the compressor ２ a first pressure sensor disposed on the side where the refrigerant flows out CO is provided to the compressor ２ a second pressure sensor disposed on the side where the refrigerant flows in, The CO flowing out of the compressor ２ a branch portion that branches the refrigerant into a first path and a second path, control means. The first path is CO ２ The first CO for adjusting the refrigerant flow rate ２ a refrigerant control valve, and The first CO ２ CO passing through the refrigerant control valve ２ a first heat exchanger that transfers heat from the refrigerant to the functional water, CO passing through the first heat exchanger ２ a first internal heat exchanger through which a refrigerant passes, CO that has passed through the first internal heat exchanger ２ a variable expansion valve that expands the refrigerant, CO that has passed through the variable expansion valve ２ a second internal heat exchanger through which the refrigerant passes, The CO that has passed through the second internal heat exchanger ２ a second heat exchanger in which the refrigerant extracts heat from industrial water, and CO that has passed through the second heat exchanger ２ The refrigerant is led to the first internal heat exchanger, and CO that has flowed out of the first heat exchanger ２ Takes heat from the refrigerant and CO that has passed through the second heat exchanger ２ Liquid CO remaining in the refrigerant ２ A first auxiliary path for vaporizing the refrigerant, and CO from the first auxiliary path ２ a first return path for guiding the refrigerant to the compressor, and is provided with The second path is CO ２ Second CO for adjusting the refrigerant flow rate ２ a refrigerant control valve, and The second CO ２ CO that has passed through the refrigerant control valve ２ The second heat exchanger that transfers heat from the refrigerant to industrial water, and CO that has passed through the second heat exchanger ２ the second internal heat exchanger through which the refrigerant passes, CO that has passed through the second internal heat exchanger ２ the variable expansion valve that expands the refrigerant, CO that has passed through the variable expansion valve ２ the first internal heat exchanger through which the refrigerant passes, CO that has passed through the first internal heat exchanger ２ the first heat exchanger in which the refrigerant takes heat from the functional water, CO that has passed through the first heat exchanger ２ The refrigerant is led to the second internal heat exchanger, and CO that has flowed out of the second heat exchanger ２ Takes heat from the refrigerant and CO that has passed through the first heat exchanger ２ Liquid CO remaining in the refrigerant ２ A second auxiliary path for vaporizing the refrigerant, and CO from the second auxiliary path ２ A temperature control device including a second return path for guiding the refrigerant to the compressor.

2. The first auxiliary path includes a first on-off valve for opening and closing the first path after the second heat exchanger, and a second on-off valve and a third on-off valve arranged so as to sandwich the first on-off valve. The second auxiliary path includes a fourth on-off valve for opening and closing the second path after the first heat exchanger, and a fifth on-off valve and a sixth on-off valve arranged so as to sandwich the fourth on-off valve. The control means is When guiding CO to the first flow path ２ when guiding the refrigerant The first CO ２ Open the refrigerant control valve, and for the second CO ２ Close the refrigerant control valve, open the fourth on-off valve, close the fifth and sixth on-off valves, close the first on-off valve, and open the second and third on-off valves. When guiding CO to the second route ２ When guiding the refrigerant The second CO ２ Open the refrigerant control valve, and the first CO ２ The temperature control device according to claim 1, wherein the refrigerant control valve is closed, the first on-off valve is opened, the second on-off valve and the third on-off valve are closed, the fourth on-off valve is closed, and the fifth on-off valve and the sixth on-off valve are opened.

3. A third CO is provided in the first return path ２ refrigerant control valve, and a fourth CO is provided in the second return path ２ refrigerant control valve The control means is When guiding CO to the first route ２ When guiding the refrigerant, open the third CO ２ refrigerant control valve and close the fourth CO ２ refrigerant control valve When guiding CO to the second path ２ When guiding the refrigerant, open the fourth CO ２ refrigerant control valve and close the third CO ２ The temperature control device according to claim 2, wherein the refrigerant control valve is closed.

4. When the control means heats the functional water by adopting the first path, The first CO ２ refrigerant control valve and the third CO ２ set the refrigerant control valve to fully open, The second CO ２ refrigerant control valve and the fourth CO ２ set the refrigerant control valve to fully closed, Function the first heat exchanger as a gas cooler to cool CO ２ Heat the functional water with a refrigerant, Function the second heat exchanger as an evaporator to cause the CO ２ refrigerant to take heat from industrial water, CO flowing out from the first heat exchanger ２ The refrigerant passes through the first internal heat exchanger and CO flowing out from the second heat exchanger ２ Heat is given to the refrigerant and CO flowing out from the second heat exchanger ２ Liquid CO remaining in the refrigerant ２ The refrigerant is vaporized to reduce the load on the compressor In addition to increasing or decreasing the heating amount of the functional water by increasing or decreasing the rotational speed of the compressor so that the temperature of the first temperature sensor for detecting the temperature of the functional water flowing into the first heat exchanger or the second temperature sensor for detecting the temperature of the functional water flowing out of the first heat exchanger becomes a predetermined temperature, the coefficient of performance is increased by changing the opening degree of the variable expansion valve so that the detected value of the first pressure sensor becomes a predetermined pressure value. The temperature control device according to claim 3, wherein a water control valve for controlling the amount of industrial water flowing into the second heat exchanger is controlled so that the temperature difference between the temperature of the third temperature sensor for detecting the temperature of the industrial water flowing into the second heat exchanger and the temperature of the fourth temperature sensor for detecting the temperature of the industrial water flowing out of the second heat exchanger becomes constant, thereby suppressing waste of the industrial water.

5. When the control means reduces the heating amount of the functional water, Reduce the rotational speed of the compressor. When the rotational speed of the compressor reaches the minimum rotational speed, further reduce the heating amount by the second CO ２ Gradually increase the opening degree of the refrigerant control valve from fully closed, The second CO ２ By increasing the opening degree of the refrigerant control valve, the detected value of the second pressure sensor is increased, and at this time, the opening degree of the variable expansion valve is decreased so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. The second CO ２ When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently the fourth CO ２ The temperature control device according to claim 4, wherein the opening degree of the refrigerant control valve is gradually increased from fully closed, and the opening degree of the variable expansion valve is further decreased so that the detected value of the first pressure sensor is maintained at a predetermined pressure value.

6. When the control means sets the heating amount of the functional water to 0, The second CO ２ When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently the fourth CO ２ Gradually increase the opening degree of the refrigerant control valve from fully closed, and further decrease and fully close the opening degree of the variable expansion valve so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. CO is present in the first path and the second path ２ The temperature control device according to claim 5, wherein since the refrigerant does not circulate, the functional water is neither heated nor cooled.

7. When the control means cools the functional water by adopting the second path, The second CO ２ refrigerant control valve and the fourth CO ２ set the refrigerant control valve to fully open, The first CO ２ refrigerant control valve and the third CO ２ set the refrigerant control valve to fully closed, Function the second heat exchanger as a gas cooler to take heat from the CO ２ refrigerant with industrial water, Function the first heat exchanger as an evaporator to cause the CO ２ refrigerant to take heat from the functional water, CO flowing out of the second heat exchanger ２ The refrigerant passes through the second internal heat exchanger and CO flowing out of the first heat exchanger ２ Heat is given to the refrigerant and CO flowing out of the first heat exchanger ２ Liquid CO remaining in the refrigerant ２ The refrigerant is vaporized to reduce the load on the compressor In addition to increasing or decreasing the cooling amount of the functional water by increasing or decreasing the rotational speed of the compressor so that the temperature of the first temperature sensor for detecting the temperature of the functional water flowing into the first heat exchanger or the second temperature sensor for detecting the temperature of the functional water flowing out of the first heat exchanger becomes a predetermined temperature, the cooling efficiency is increased by changing the opening degree of the variable expansion valve so that the detected value of the first pressure sensor becomes a predetermined pressure value. CO flowing out of the second heat exchanger ２ The temperature control device according to claim 3, which controls a water control valve that controls the amount of industrial water flowing into the second heat exchanger based on the temperature of a third temperature sensor that detects the temperature of the industrial water flowing into the second heat exchanger so that the temperature of a fifth temperature sensor that detects the temperature of the refrigerant becomes a predetermined temperature, thereby adjusting the flow rate of the industrial water.

8. When the control means reduces the cooling amount of the functional water, Reduce the rotational speed of the compressor. When the rotational speed of the compressor reaches the minimum rotational speed, further reduce the cooling capacity by using the first CO ２ Gradually increase the opening degree of the refrigerant control valve from fully closed, The first CO ２ By increasing the opening degree of the refrigerant control valve, the detected value of the second pressure sensor is increased, and at this time, the opening degree of the variable expansion valve is decreased so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. The first CO ２ When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently the third CO ２ The temperature control device according to claim 7, wherein the opening degree of the refrigerant control valve is gradually increased from fully closed, and the opening degree of the variable expansion valve is further decreased so that the detected value of the first pressure sensor is maintained at a predetermined pressure value.

9. When the control means sets the cooling amount of the functional water to 0, The first CO ２ When the opening degree of the refrigerant control valve reaches the maximum opening degree, subsequently the third CO ２ Gradually increase the opening degree of the refrigerant control valve from fully closed, and further decrease and fully close the opening degree of the variable expansion valve so that the detected value of the first pressure sensor is maintained at a predetermined pressure value. CO is present in the first path and the second path ２ The temperature control device according to claim 8, wherein since the refrigerant does not circulate, the functional water is neither cooled nor heated.

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