cooler

Abstract

The present invention provides a cooler which is small, low in cost, and energy efficient. The cooler (C1, C2) has a tank (1), a pump (2), a plurality of coolant circuits (3, 4) for cooling a plurality of loads, respectively, and a refrigerant circuit (5, 5A), the plurality of coolant circuits (3, 4) and the refrigerant circuit (5, 5A) being connected to each other via individual heat exchangers (6, 7) capable of controlling the cooling capacity, respectively, the first heat exchanger (6) connecting the first coolant circuit (3) and the refrigerant circuit (5, 5A) adjusts the temperature of the coolant returned from the first load (W1) and the second load (W2) to the tank (1), and the second heat exchanger (7) connecting the second coolant circuit (4) and the refrigerant circuit (5, 5A) adjusts the temperature of the coolant supplied from the tank (1) to the second load (W2).

Description

TECHNICAL FIELD

[0001] The present application relates to a cooler that keeps the temperature of a load constant by supplying the load with temperature-adjusted coolant, and more particularly to a cooler that can keep the temperature of a plurality of loads constant. BACKGROUND

[0002] A cooler that keeps the temperature of a plurality of loads constant by supplying the loads with temperature-adjusted coolant is known as disclosed in Patent Document 1 to Patent Document 3, etc.

[0003] The cooler disclosed in Patent Document 1 (first cooler) has one refrigeration circuit, two coolant circuits that supply coolant to two loads, respectively, and two heat exchangers that connect the two coolant circuits and the refrigeration circuit, respectively, and adjusts the temperature of the coolant of one of the coolant circuits with one of the heat exchangers and adjusts the temperature of the coolant of the other of the coolant circuits with the other of the heat exchangers.

[0004] Since the first cooler adjusts the temperature of the coolant of the two coolant circuits with the two heat exchangers, respectively, it can correspond to two loads that differ in temperature. However, since the two coolant circuits each have a dedicated tank and pump, the first cooler is high in cost, and in the case where the two coolant circuits and the refrigeration circuit are housed in one housing, there is a problem that the cooler is large in size.

[0005] On the other hand, the coolers disclosed in Patent Document 2 and Patent Document 3 (second cooler and third cooler) have one tank, one pump, and a plurality of coolant circuits, supply the coolant discharged from the one pump to the plurality of coolant circuits distributively, cool a plurality of loads with the coolant circuits, and use one tank and one pump, and thus can be smaller in size than the first cooler.

[0006] However, the second cooler and the third cooler cannot correspond to a plurality of loads that differ in temperature since the coolant temperature-adjusted with one heat exchanger is supplied to the plurality of coolant circuits distributively.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT DOCUMENTS

[0009] Patent Document 1: Japanese Patent No. 5-17535

[0010] Patent Document 2: Japanese Patent Application Publication No. 2004-28554

[0011] Patent Document 3: Japanese Patent Application Publication No. 2011-163698 SUMMARY

[0012] Problem to be solved by the Invention

[0013] The present application has an object to provide a cooler which is capable of realizing downsizing, cost reduction and energy saving compared with a conventional cooler, and which has a reasonable configuration capable of coping with a plurality of loads having different temperatures.

[0014] Means for solving the problem

[0015] To solve the above problem, the cooler of the present application is characterized by comprising: a tank which houses a cooling liquid; a pump which discharges the cooling liquid in the tank; a plurality of cooling liquid circuits which branch the cooling liquid discharged by the pump and supply the cooling liquid to a plurality of loads, respectively; and a refrigeration circuit which adjusts the temperature of the cooling liquid by heat exchange between the cooling liquid and a refrigerant, the plurality of cooling liquid circuits and the refrigeration circuit being connected to each other via individual heat exchangers capable of individually controlling the heat exchange capacity, the plurality of cooling liquid circuits including a first cooling liquid circuit which cools a first load and a second cooling liquid circuit which cools a second load having a temperature different from that of the first load, a first heat exchanger which connects the first cooling liquid circuit and the refrigeration circuit adjusting the temperature of the cooling liquid returned from the first and second loads to the tank, and a second heat exchanger which connects the second cooling liquid circuit and the refrigeration circuit adjusting the temperature of the cooling liquid supplied from the tank to the second load.

[0016] In the present application, the first cooling liquid circuit can include a first supply line which supplies the cooling liquid discharged from the pump to the first load while maintaining the temperature in the tank at a first set temperature, and a first return line which returns the cooling liquid from the first load to the tank, the first heat exchanger being connected to the first return line, whereby the cooling liquid in the first return line is adjusted to the first set temperature in the first heat exchanger and then flows into the tank, and the second cooling liquid circuit can include a branch line which branches from the first supply line and is connected to the second heat exchanger, a second supply line which supplies the cooling liquid adjusted to a second set temperature in the second heat exchanger to the second load, and a second return line which returns the cooling liquid from the second load to the tank, the second return line being connected to the first return line, whereby the cooling liquid in the second return line is combined with the cooling liquid in the first return line.

[0017] Further, in the present application, a pressure adjusting valve which makes the pressure of the cooling liquid flowing in the second cooling liquid circuit different from the pressure of the cooling liquid flowing in the first cooling liquid circuit is connected to the second supply line.

[0018] Further, in the present application, a filter line connecting the first supply line and the first return line can be provided on the first cooling liquid circuit, a DI filter adjusting the electric conductivity of the cooling liquid and a solenoid valve opening and closing the filter line can be connected to the filter line, and a DI sensor measuring the electric conductivity of the cooling liquid flowing in the first return line can be connected to the first return line, and the solenoid valve can be opened and closed based on the measurement of the DI sensor.

[0019] Preferably, the filter line connects a position of the first supply line closer to the first load than a position at which the branch line branches, and a position of the first return line closer to the first heat exchanger than a position at which the second return line merges.

[0020] In the present application, the refrigeration circuit has a first refrigerant line connecting an outlet of a compressor and an inlet of a condenser, a second refrigerant line connecting an outlet of the condenser and an inlet of a first heat exchanger, a third refrigerant line connecting an outlet of the first heat exchanger and an inlet of the compressor, a fourth refrigerant line connecting the first refrigerant line and an inlet of a second heat exchanger, a fifth refrigerant line connecting an outlet of the second heat exchanger and the inlet of the first heat exchanger, and a sixth refrigerant line connecting the fourth refrigerant line and the fifth refrigerant line, a first expansion valve is connected to the second refrigerant line, a second expansion valve is connected to the fifth refrigerant line, and a third expansion valve is connected to the sixth refrigerant line.

[0021] Further, in the present application, the refrigeration circuit can have a first refrigerant line connecting an outlet of a compressor and an inlet of a condenser, a second refrigerant line connecting an outlet of the condenser and an inlet of a first heat exchanger, a third refrigerant line connecting the second refrigerant line and an inlet of a second heat exchanger, a fourth refrigerant line connecting an outlet of the first heat exchanger and an inlet of the compressor, a fifth refrigerant line connecting an outlet of the second heat exchanger and the fourth refrigerant line, a sixth refrigerant line branching from the first refrigerant line and connecting the inlet of the first heat exchanger, and a seventh refrigerant line branching from the sixth refrigerant line and connecting the inlet of the second heat exchanger, a first expansion valve is connected to the second refrigerant line, a second expansion valve is connected to the third refrigerant line, a third expansion valve is connected to the sixth refrigerant line, and a fourth expansion valve is connected to the seventh refrigerant line.

[0022] Effects of the Invention

[0023] The cooler of the present application supplies coolant to a plurality of coolant circuits by a tank and a pump, and adjusts the temperature of the coolant of each of the coolant circuits to different set temperatures by individual heat exchangers capable of individually controlling heat exchange capacity, and thus is small and low in cost, and energy saving, as compared with a known cooler having a dedicated tank and pump for each of the coolant circuits. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a circuit diagram showing a first embodiment of a cooler to which the present application is applied.

[0025] Figure 2 is a circuit diagram showing a second embodiment of a cooler to which the present application is applied. DETAILED DESCRIPTION

[0026] Figure 1 The cooler Cl shown in the first embodiment is a cooler that keeps two loads Wl, W2, which are different in temperature, at constant temperatures by cooling them with coolant, and has a tank 1 that houses coolant, a pump 2 that discharges the coolant in the tank 1, two coolant circuits 3, 4 that branch the coolant discharged from the pump 2 and supply it to the two loads Wl, W2, respectively, a refrigeration circuit 5 that adjusts the temperature of the coolant of the two coolant circuits 3, 4 to set temperatures, respectively, two heat exchangers 6, 7 that connect the refrigeration circuit 5 to the two coolant circuits 3, 4, respectively, and a control device 8 that controls the entire cooler. In the present embodiment, pure water is used as the coolant.

[0027] Of the two loads Wl, W2, the first load Wl is a laser oscillator in a laser welding device, which is a low-temperature load, and the second load W2 is a probe irradiated with laser light, which is a load higher in temperature than the laser oscillator.

[0028] In the two coolant circuits 3, 4, the first coolant circuit 3 cools the first load Wl, and the second coolant circuit 4 cools the second load W2.

[0029] In the two heat exchangers 6, 7, the first heat exchanger 6 connects the first coolant circuit 3 to the refrigeration circuit 5, and the second heat exchanger 7 connects the second coolant circuit 4 to the refrigeration circuit 5.

[0030] In the first coolant circuit 3, for example, the temperature of the coolant supplied to the first load Wl is set to an optimum temperature in the range of 10 to 30°C, preferably in the range of 15 to 25°C, and the flow rate of the coolant is set to an optimum flow rate in the range of 20 to 80 L / min.

[0031] On the other hand, in the above-mentioned second coolant circuit 4, the temperature of the coolant supplied to the above-mentioned second load W2 is set to an optimum temperature in the range of 10 to 50°C, preferably in the range of 20 to 40°C, and the flow rate of the coolant is set to an optimum flow rate in the range of 2 to 10 L / min. However, the set temperature of the coolant supplied to the second load W2 needs to be equal to or higher than the set temperature of the coolant supplied to the first load Wl.

[0032] The above-mentioned refrigeration circuit 5, one tank 1, one pump 2, and two coolant circuits 3, 4 are housed inside a frame 9, and the above-mentioned two loads Wl, W2 are arranged outside the frame 9. Further, on the outer side surface of the frame 9, a supply-side load connection port 10 and a return-side load connection port 11 for connecting the above-mentioned first load Wl to the above-mentioned first coolant circuit 3, and a supply-side load connection port 12 and a return-side load connection port 13 for connecting the above-mentioned second load W2 to the above-mentioned second coolant circuit 4 are provided, respectively.

[0033] The above-mentioned refrigeration circuit 5 has a compressor 15 which compresses a gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant, and a condenser 16 which cools the high-temperature and high-pressure gaseous refrigerant sent from the compressor 15 into a low-temperature and high-pressure liquid refrigerant. The condenser 16 is an air-cooled condenser 16 which cools the refrigerant by a fan 17 driven by an electric motor 17a, and these electric motors 17a and the compressor 15 are electrically connected to a control device 8, and the rotational speed and output of each are controlled by inverter control by the control device 8. However, the above-mentioned condenser 16 can also be a water-cooled type.

[0034] Further, the above-mentioned refrigeration circuit 5 has a first refrigerant line 21 which links the outlet 15a of the above-mentioned compressor 15 and the inlet 16a of the above-mentioned condenser 16, a second refrigerant line 22 which links the outlet 16b of the above-mentioned condenser 16 and the inlet 6a of the above-mentioned first heat exchanger 6, a third refrigerant line 23 which links the outlet 6b of the first heat exchanger 6 and the inlet 15b of the above-mentioned compressor 15, a fourth refrigerant line 24 which links the above-mentioned first refrigerant line 21 and the inlet 7a of the above-mentioned second heat exchanger 7, a fifth refrigerant line 25 which links the outlet 7b of the above-mentioned second heat exchanger 7 and the inlet 6a of the above-mentioned first heat exchanger 6, and a sixth refrigerant line 26 which links the above-mentioned fourth refrigerant line 24 and the fifth refrigerant line 25. Further, a first expansion valve 27 is connected to the above-mentioned second refrigerant line 22, a second expansion valve 28 is connected to the above-mentioned fifth refrigerant line 25 at a position closer to the outlet 7b of the above-mentioned second heat exchanger 7 than a position at which the above-mentioned sixth refrigerant line 26 is connected, and a third expansion valve 29 is connected to the above-mentioned sixth refrigerant line 26.

[0035] Further, the first heat exchanger 6 and the second heat exchanger 7 have a refrigerant flow passage 6A, 7A through which refrigerant flows and a coolant flow passage 6B, 7B through which coolant flows, and exchange heat between the refrigerant flowing through the refrigerant flow passage 6A, 7A and the coolant flowing through the coolant flow passage 6B, 7B. Therefore, in the above-described refrigerant circuit 5, the inlet of the first heat exchanger 6 and the second heat exchanger 7 refers to the inlet 6a, 7a of the refrigerant flow passage 6A, 7A, and the outlet of the first heat exchanger 6 and the second heat exchanger 7 refers to the outlet 6b, 7b of the refrigerant flow passage 6A, 7A. Further, in the first coolant circuit 3 and the second coolant circuit 4 described later, the inlet of the first heat exchanger 6 and the second heat exchanger 7 refers to the inlet 6c, 7c of the coolant flow passage 6B, 7B, and the outlet of the first heat exchanger 6 and the second heat exchanger 7 refers to the outlet 6d, 7d of the coolant flow passage 6B, 7B.

[0036] The first expansion valve 27, the second expansion valve 28, and the third expansion valve 29 are electronic expansion valves whose opening degree can be arbitrarily adjusted by a stepping motor, and are electrically connected to the control device 8, and the opening degree of each of the expansion valves 27, 28, 29 is controlled by the control device 8.

[0037] The first refrigerant temperature sensor 30 that detects the temperature of the refrigerant discharged from the compressor 15 is connected to the first refrigerant circuit 21, and the refrigerant filter 31 that removes foreign matter in the refrigerant and the first refrigerant pressure sensor 32 that detects the pressure of the refrigerant are connected to the second refrigerant circuit 22 at a position between the condenser 16 and the first expansion valve 27, and the second refrigerant pressure sensor 33 that detects the pressure of the refrigerant returned to the compressor 15 from the first heat exchanger 6 and the second refrigerant temperature sensor 34 that detects the temperature of the refrigerant are connected to the third refrigerant circuit 23.

[0038] The refrigerant temperature sensors 30, 34 and the refrigerant pressure sensors 32, 33 are electrically connected to the control device 8, and based on the measured refrigerant temperature and refrigerant pressure, the rotation speed and output of the compressor 15 and the fan 17 are controlled by the control device 8.

[0039] The first coolant circuit 3 has a first supply circuit 40 that connects the jet port 2a of the pump 2 and the supply-side load connection port 10, a first return circuit 41 that connects the return-side load connection port 11 and the inlet 6c of the first heat exchanger 6, and an inflow circuit 42 that connects the outlet 6d of the first heat exchanger 6 and the tank 1.

[0040] Thus, in the first coolant circuit 3, the coolant discharged from the tank 1 by the pump 2 is supplied to the first load Wl through the first supply line 40 at the first set temperature, i.e., the temperature in the tank 1, and cools the first load Wl. The coolant warmed by cooling the first load Wl is sent to the first heat exchanger 6 through the first return line 41, and is returned to the tank 1 from the inflow line 42 after temperature adjustment in the first heat exchanger 6.

[0041] The first temperature sensor 43 for detecting the temperature of the coolant supplied to the first load Wl and the pressure sensor 44 for detecting the pressure of the coolant are connected to the first supply line 40, and the second temperature sensor 45 for detecting the temperature of the coolant returned to the tank 1 from the first load Wl is connected to the first return line 41.

[0042] The first temperature sensor 43, the second temperature sensor 45, and the pressure sensor 44 are electrically connected to the control device 8. The opening degree of the expansion valves 27, 28, and 29 is adjusted by the control device 8 based on the temperature of the coolant detected by the first temperature sensor 43 and the second temperature sensor 45, thereby controlling the heat exchange capacity of the first heat exchanger 6. The pump 2 is controlled by the control device 8 based on the pressure of the coolant detected by the pressure sensor 44.

[0043] In addition, the member denoted by reference numeral 46 is a liquid level switch for detecting the liquid level of the coolant in the tank 1, and the member denoted by reference numeral 47 is a drain discharge pipe.

[0044] In addition, the pump 2 is a non-immersed pump provided outside the tank 1.

[0045] On the other hand, the second coolant circuit 4 has a branch line 50 branched from the first supply line 40 of the first coolant circuit 3 and connected to the inlet 7c of the second heat exchanger 7, a second supply line 51 connecting the outlet 7d of the second heat exchanger 7 and the supply-side load connection port 12, and a second return line 52 connecting the return-side load connection port 13 and the first return line 41 of the first coolant circuit 3. The position at which the second return line 52 is connected to the first return line 41 is a position on the upstream side (closer to the return-side load connection port 11) than the position at which the second temperature sensor 45 is provided.

[0046] According to this structure, in the second cooling liquid circuit 4, the cooling liquid discharged from the pump 2 is sent to the second heat exchanger 7 through the branch pipe 50, is adjusted to a second set temperature different from the first set temperature in the second heat exchanger 7, is sent to the second load W2 through the second supply pipe 51, and cools the second load W2. Further, the cooling liquid warmed by cooling the second load W2 flows into the first return pipe 41 from the second return pipe 52, is combined with the cooling liquid of the first cooling liquid circuit 3 flowing in the first return pipe 41, and is sent to the first heat exchanger 6. The cooling liquid is temperature-adjusted in the first heat exchanger 6 to return to the first set temperature, and flows into the tank 1 from the inflow pipe 42.

[0047] Here, since the second load W2 is higher in temperature than the first load Wl, the set temperature of the cooling liquid of the second cooling liquid circuit 4 (second set temperature) is higher than the set temperature of the cooling liquid of the first cooling liquid circuit 3 (first set temperature). Therefore, the second heat exchanger 7 heats the cooling liquid sent from the tank 1 via the first cooling liquid circuit 3 and the branch pipe 50 while maintaining the first set temperature, and raises the temperature of the cooling liquid to the second set temperature. Therefore, the second heat exchanger 7 can be said to be a heat exchanger for heating.

[0048] The third temperature sensor 53 and the pressure adjusting valve 54 that change the pressure of the cooling liquid supplied to the second load W2 are connected in series to the second supply pipe 51.

[0049] The third temperature sensor 53 and the pressure adjusting valve 54 are electrically connected to the control device 8, and the opening degree of the second expansion valve 28 is adjusted by the control device 8 based on the temperature of the cooling liquid measured by the third temperature sensor 53, whereby the heat exchange capacity of the second heat exchanger 7 is controlled. Further, in a case where it is necessary to make the pressure of the cooling liquid flowing in the second supply pipe 51 different from the pressure of the cooling liquid flowing in the first supply pipe 40, the pressure adjusting valve 54 is controlled by the control device 8. However, the pressure adjusting valve 54 can also be a manually operated valve.

[0050] In addition, in the first coolant circuit 3, a filter line 60 for purifying the coolant whose purity is reduced due to an increase in ionic substances is provided. One end of the filter line 60 is connected to a position downstream of the position at which the first supply line 40 branches from the branch line 50 (a position close to the first load Wl), and the other end of the filter line 60 is connected to a position downstream of the position at which the second return line 52 is connected to the first return line 41 (a position close to the first heat exchanger 6). Further, a DI filter 61 for removing ionic substances and a solenoid valve 62 for opening and closing the filter line 60 are connected in series to the filter line 60. In addition, a DI sensor 63 for measuring the conductivity of the coolant is connected to the point at which the filter line 60 and the first return line 41 join.

[0051] The DI filter 61 is detachably connected to filter connection portions 64 and 65 formed in the filter line 60, and removes ionic substances in the coolant by ion exchange, in which the ionic substances are adsorbed on the surface of a resin. The DI filter 61 can be disposed inside the frame 9 or outside the frame 9.

[0052] Further, the solenoid valve 62 and the DI sensor 63 are electrically connected to the control device 8, and the solenoid valve 62 is controlled to open and close by the control device 8 based on the conductivity measured by the DI sensor 63.

[0053] The filter line 60 operates as follows. That is, when the conductivity of the coolant in the first return line 41 measured by the DI sensor 63 is higher than a reference value due to an increase in ionic substances, the conductivity of the coolant in the tank 1 to which the coolant flows back also becomes high. Therefore, the solenoid valve 62 is opened by the control device 8, and the coolant in the first supply line 40 flows into the filter line 60, whereby the ionic substances in the coolant are removed by the DI filter 61, and the purified coolant is supplied to the tank 1 through the first return line 41. By continuing this operation, the coolant in the tank 1 is purified. As a result, the coolant in the first coolant circuit 3 and the coolant in the second coolant circuit 4 can be kept at the same purity (liquid quality) at all times.

[0054] The cooler Cl of the first embodiment operates as follows.

[0055] In the above refrigeration circuit 5, the high-temperature and high-pressure gaseous refrigerant discharged from the above compressor 15 is cooled to become low-temperature and high-pressure liquid refrigerant in the above condenser 16, and is then sent to the first heat exchanger 6 from the above second refrigerant line 22 through the first expansion valve 27, exchanges heat with the coolant of the above first coolant circuit 3 in the first heat exchanger 6 to cool the coolant to the first set temperature, and is then returned to the above compressor 15 through the third refrigerant line 23.

[0056] In addition, a part of the high-temperature and high-pressure gaseous refrigerant discharged from the above compressor 15 is sent to the above second heat exchanger 7 through the above fourth refrigerant line 24, exchanges heat with the coolant of the above second coolant circuit 4 in the second heat exchanger 7 to heat the coolant to the second set temperature, and then flows into the above first heat exchanger 6 through the second expansion valve 28 of the fifth refrigerant line 25. At this time, the above gaseous refrigerant is condensed by heating the coolant in the above second heat exchanger 7, and is then expanded in the above second expansion valve 28 to become a state in which the temperature is further lowered, and in this state, the refrigerant of the above second refrigerant line 22 is merged and flows into the above first heat exchanger 6, thereby playing a role of assisting in increasing the cooling capacity of the first heat exchanger 6. This is because the above second expansion valve 28 is connected between the outlet of the above second heat exchanger 7 and the inlet of the first heat exchanger 6, and the above second heat exchanger 7 functions as a condenser 16.

[0057] Furthermore, a part of the high-temperature and high-pressure gaseous refrigerant discharged from the above compressor 15 is sent to the above first heat exchanger 6 from the above sixth refrigerant line 26 via the third expansion valve 29, for temperature adjustment of the refrigerant flowing into the first heat exchanger 6.

[0058] On the other hand, in the above first coolant circuit 3, the coolant in the above tank 1 adjusted to the first set temperature is sent to the first load Wl at the first set temperature through the first supply line 40 after being discharged from the above pump 2, and cools the first load Wl.

[0059] The coolant warmed by cooling the above first load Wl is sent to the above first heat exchanger 6 through the first return line 41, is adjusted to the above first set temperature in the first heat exchanger 6, and then flows into the above tank 1 from the above inflow line 42.

[0060] The temperature of the above coolant is always measured by the above first temperature sensor 43 and the second temperature sensor 45, and based on the measured temperature of the coolant, the opening degree of the first expansion valve 27 and the third expansion valve 29 of the refrigeration circuit 5 is controlled by the above control device 8, thereby adjusting the temperature of the coolant to the first set temperature.

[0061] For example, in the case where the temperature of the coolant determined by the above-mentioned first temperature sensor 43 is higher than the first set temperature, it is required to increase the cooling capacity of the above-mentioned first heat exchanger 6 to lower the temperature of the coolant, and therefore the opening degree of the first expansion valve 27 in the above-mentioned refrigeration circuit 5 is enlarged to increase the flow rate of the low-temperature refrigerant, and the opening degree of the above-mentioned third expansion valve 29 is reduced to decrease the flow rate of the high-temperature refrigerant. As a result, the cooling capacity of the above-mentioned first heat exchanger 6 is increased due to the decrease in the temperature of the refrigerant flowing into the first heat exchanger 6, and therefore the coolant is cooled and its temperature is adjusted to the first set temperature.

[0062] On the contrary, in the case where the temperature of the coolant is lower than the first set temperature, it is required to heat the coolant by the above-mentioned first heat exchanger 6 to increase the temperature, and therefore the opening degree of the above-mentioned first expansion valve 27 is reduced to decrease the flow rate of the low-temperature refrigerant, and the opening degree of the above-mentioned third expansion valve 29 is enlarged to increase the flow rate of the high-temperature refrigerant. As a result, the temperature of the refrigerant flowing into the above-mentioned first heat exchanger 6 is increased, and the coolant is heated by the warmed refrigerant to adjust its temperature to the first set temperature.

[0063] Further, in the above-mentioned second coolant circuit 4, a part of the coolant discharged from the above-mentioned pump 2 at the first set temperature flows into the second heat exchanger 7 through the branch pipe 50, is heated in the second heat exchanger 7 by heat exchange with the high-temperature high-pressure gaseous refrigerant, and after being adjusted to the second set temperature which is higher than the above-mentioned first set temperature, is sent to the second load W2 through the above-mentioned second supply pipe 51 to cool the second load W2.

[0064] The coolant warmed by cooling the above-mentioned second load W2 flows into the first return pipe 41 from the above-mentioned second return pipe 52, is merged with the coolant from the first load Wl flowing in the first return pipe 41 to be sent to the above-mentioned first heat exchanger 6, is temperature-adjusted to the first set temperature in the first heat exchanger 6, and then flows into the above-mentioned tank 1 from the above-mentioned inflow pipe 42.

[0065] The temperature of the coolant supplied to the above-mentioned second load W2 is always determined by the third temperature sensor 53 connected to the above-mentioned second supply pipe 51, and based on the determined temperature, the opening degree of the second expansion valve 28 of the refrigeration circuit 5 is controlled by the above-mentioned control device 8 to adjust the temperature of the coolant to the second set temperature.

[0066] For example, in the case where the temperature of the coolant flowing through the second supply line 51 is higher than the second set temperature, the temperature of the coolant needs to be lowered, and therefore the heating capacity of the second heat exchanger 7 is reduced by reducing or closing the opening degree of the second expansion valve 28 in the refrigeration circuit 5, as a result, the temperature of the coolant is lowered and adjusted to the second set temperature.

[0067] On the contrary, in the case where the temperature of the coolant flowing through the second supply line 51 is lower than the second set temperature, the temperature of the coolant needs to be raised, and therefore the opening degree of the second expansion valve 28 is increased and the flow rate of the high-temperature refrigerant flowing into the second heat exchanger 7 is increased, as a result, the coolant is heated and its temperature is adjusted to the second set temperature.

[0068] In addition, if the amount of ionic substances in the coolant increases, the conductivity of the coolant increases, but in the case where the conductivity measured by the DI sensor 63 is greater than the reference value, the electromagnetic valve 62 is opened and the filter line 60 is opened, and the coolant flows in the filter line 60, whereby the ionic substances in the coolant are removed by the DI filter 61.

[0069] At this time, it is possible to continue cooling the load while flowing a part of the coolant in the filter line 60 to filter, and it is also possible to stop cooling the load and flow all of the coolant in the filter line 60 to filter.

[0070] Figure 2 A cooler C2 according to a second embodiment is shown. The cooler C2 differs from the cooler Cl according to the first embodiment in the structure of the refrigeration circuit 5A, and the structures of the first coolant circuit 3 and the second coolant circuit 4, and the first heat exchanger 6 and the second heat exchanger 7 are the same as those of the cooler according to the first embodiment.

[0071] Therefore, in the following description, the structure of the refrigeration circuit 5A is described, and the same reference numerals as those used in the first embodiment are used for the first coolant circuit 3 and the second coolant circuit 4, and the first heat exchanger 6 and the second heat exchanger 7, and the description thereof is omitted.

[0072] The above refrigerant circuit 5A has a first refrigerant line 72 connecting the outlet 70a of the compressor 70 and the inlet 71a of the condenser 71, a second refrigerant line 73 connecting the outlet 71b of the condenser 71 and the inlet 6a of the above first heat exchanger 6, a third refrigerant line 74 branching from the second refrigerant line 73 and connected to the inlet 7a of the second heat exchanger 7, a fourth refrigerant line 75 connecting the outlet 6b of the above first heat exchanger 6 and the inlet 70b of the above compressor 70, and a fifth refrigerant line 76 connecting the outlet 7b of the above second heat exchanger 7 and the above fourth refrigerant line 75. Further, the first expansion valve 77 is connected at a position of the second refrigerant line 73 closer to the first heat exchanger 6 than the branching position of the third refrigerant line 74, and the second expansion valve 78 is connected at the third refrigerant line 74.

[0073] Further, a sixth refrigerant line 79 branching from the above first refrigerant line 72 is connected to the above second refrigerant line 73 at a position closer to the inlet 6a of the above first heat exchanger 6 than the above first expansion valve 77, and the third expansion valve 80 is connected at the sixth refrigerant line 79, and a seventh refrigerant line 81 branching from the above sixth refrigerant line 79 is connected to the above third refrigerant line 74 at a position closer to the inlet 7a of the above second heat exchanger 7 than the above second expansion valve 78, and the fourth expansion valve 82 is connected at the seventh refrigerant line 81.

[0074] The first refrigerant temperature sensor 83 detecting the temperature of the refrigerant discharged from the above compressor 70 is connected at the above first refrigerant line 72, the refrigerant filter 84 removing foreign matters in the refrigerant flowing from the above condenser 71 and the first refrigerant pressure sensor 85 detecting the pressure of the refrigerant are connected at the above second refrigerant line 73, and the second refrigerant pressure sensor 86 detecting the pressure of the refrigerant returned to the above compressor 70 from the above first heat exchanger 6 and second heat exchanger 7 and the second refrigerant temperature sensor 87 detecting the temperature of the refrigerant are connected at the above fourth refrigerant line 75.

[0075] The cooler of the above second embodiment operates as follows.

[0076] In the above-described refrigeration circuit 5A, the high-temperature and high-pressure gaseous refrigerant discharged from the above-described compressor 70 is cooled to become low-temperature and high-pressure liquid refrigerant in the above-described condenser 71, and is then sent to the first heat exchanger 6 from the above-described second refrigerant line 73 through the first expansion valve 77, and is sent to the second heat exchanger 7 from the above-described third refrigerant line 74 through the second expansion valve 78, exchanges heat with the coolant of the above-described first coolant circuit 3 in the above-described first heat exchanger 6 to adjust the coolant to the first set temperature, and exchanges heat with the coolant of the above-described second coolant circuit 4 in the above-described second heat exchanger 7 to adjust the coolant to the second set temperature. Also, the refrigerant flowing out from the above-described first heat exchanger 6 and second heat exchanger 7 returns to the inlet 70b of the compressor 70 through the fourth refrigerant line 75 and the fifth refrigerant line 76.

[0077] In addition, a part of the high-temperature and high-pressure gaseous refrigerant discharged from the above-described compressor 70 is sent to the above-described first heat exchanger 6 via the above-described sixth refrigerant line 79 and the third expansion valve 80, and is sent to the above-described second heat exchanger 7 via the above-described seventh refrigerant line 81 and the fourth expansion valve 82, for temperature adjustment of the refrigerant flowing into each heat exchanger 6, 7.

[0078] On the other hand, in the above-described first coolant circuit 3, the coolant in the above-described tank 1 adjusted to the first set temperature is sent to the first load Wl through the first supply line 40 after being discharged from the above-described pump 2, and is sent to the first load Wl at the first set temperature, and the first load Wl is cooled.

[0079] The coolant warmed by cooling the above-described first load Wl is sent to the above-described first heat exchanger 6 through the first return line 41, and is returned to the above-described first set temperature in the first heat exchanger 6, and is then sent to the above-described tank 1 from the above-described inflow line 42.

[0080] The temperature of the above-described coolant is always measured by the above-described first temperature sensor 43 and second temperature sensor 45, and based on the measured temperature of the coolant, the opening degree of the first expansion valve 77 and third expansion valve 80 of the refrigeration circuit 5A is controlled by the above-described control device 8, and thereby the temperature of the coolant is adjusted to the first set temperature.

[0081] For example, in the case where the temperature of the coolant determined by the above-mentioned first temperature sensor 43 is higher than the first set temperature, it is required to increase the cooling capacity of the above-mentioned first heat exchanger 6 to lower the temperature of the coolant, and therefore the opening degree of the first expansion valve 77 in the above-mentioned refrigerant circuit 5A is enlarged to increase the flow rate of the low-temperature refrigerant, and the opening degree of the above-mentioned third expansion valve 80 is reduced to decrease the flow rate of the high-temperature refrigerant. As a result, since the temperature of the refrigerant flowing into the above-mentioned first heat exchanger 6 is lowered and the cooling capacity of the first heat exchanger 6 is increased, the above-mentioned coolant is cooled and its temperature is adjusted to the first set temperature.

[0082] On the contrary, in the case where the temperature of the coolant is lower than the first set temperature, it is required to heat the coolant by the above-mentioned first heat exchanger 6 to increase the temperature, and therefore the opening degree of the above-mentioned first expansion valve 77 is reduced to decrease the flow rate of the low-temperature refrigerant, and the opening degree of the above-mentioned third expansion valve 80 is enlarged to increase the flow rate of the high-temperature refrigerant. As a result, the temperature of the refrigerant flowing into the above-mentioned first heat exchanger 6 is raised, and the above-mentioned coolant is heated by the warmed refrigerant to adjust its temperature to the first set temperature.

[0083] Further, in the above-mentioned second coolant circuit 4, a part of the coolant discharged from the above-mentioned pump 2 at the first set temperature flows into the second heat exchanger 7 through the branch pipe 50, is warmed by heat exchange with the refrigerant in the second heat exchanger 7, and after being adjusted to the second set temperature which is higher than the above-mentioned first set temperature, is sent to the second load W2 through the above-mentioned second supply pipe 51 to cool the second load W2.

[0084] The coolant warmed by cooling the above-mentioned second load W2 flows into the first return pipe 41 from the above-mentioned second return pipe 52, merges with the coolant from the above-mentioned first load Wl to be sent to the above-mentioned first heat exchanger 6, is temperature-adjusted to the first set temperature in the first heat exchanger 6, and then flows into the above-mentioned tank 1 from the above-mentioned inflow pipe 42.

[0085] The temperature of the coolant supplied to the above-mentioned second load W2 is always determined by the third temperature sensor 53 connected to the above-mentioned second supply pipe 51, and based on the determined temperature, the opening degrees of the second expansion valve 78 and the fourth expansion valve 82 of the refrigerant circuit 5A are controlled by the above-mentioned control device 8 to adjust the temperature of the coolant to the second set temperature.

[0086] For example, in the case where the temperature of the coolant determined by the third temperature sensor 53 is higher than the second set temperature, it is necessary to increase the cooling capacity of the second heat exchanger 7 to lower the temperature of the coolant, and therefore the opening degree of the second expansion valve 78 in the refrigerant circuit 5A is enlarged to increase the flow rate of the low-temperature refrigerant, and the opening degree of the fourth expansion valve 82 is reduced to decrease the flow rate of the high-temperature refrigerant. As a result, since the temperature of the refrigerant flowing into the second heat exchanger 7 is lowered and the cooling capacity of the second heat exchanger 7 is increased, the coolant is cooled and its temperature is adjusted to the second set temperature.

[0087] On the contrary, in the case where the temperature of the coolant is lower than the second set temperature, it is necessary to heat the coolant by the second heat exchanger 7 to increase the temperature, and therefore the opening degree of the second expansion valve 78 is reduced to decrease the flow rate of the low-temperature refrigerant, and the opening degree of the fourth expansion valve 82 is enlarged to increase the flow rate of the high-temperature refrigerant. As a result, the temperature of the refrigerant flowing into the second heat exchanger 7 is raised, and the coolant is heated by the refrigerant after the temperature is raised to adjust its temperature to the second set temperature.

[0088] Further, in the case where the amount of the ionic substance in the coolant is increased and the purity of the coolant is lowered, the ionic substance is removed by the action of the DI filter 61, as in the case of the first embodiment.

[0089] The cooler CI of the first embodiment and the cooler C2 of the second embodiment each have two coolant circuits 3, 4, but the cooler of the present application can have three or more coolant circuits. For example, one first coolant circuit 3 and two or more second coolant circuits 4 can be provided, or two or more first coolant circuits 3 and one second coolant circuit 4 can be provided, or two or more first coolant circuits 3 and two or more second coolant circuits 4 can be provided.

[0090] Here, in the cooler CI of the first embodiment, in the case where two or more first coolant circuits 3 are provided, the first coolant circuits 3 and the circuit-constituting portions formed by connecting the refrigerant circuit portion 5a including the first expansion valve 27 and the third expansion valve 29 to each other through the first heat exchanger 6 in parallel with each other, and, in the case where two or more second coolant circuits 4 are provided, the second coolant circuits 4 and the circuit-constituting portions formed by connecting the refrigerant circuit portion 5b including the second expansion valve 28 to each other through the second heat exchanger 7 in parallel with each other.

[0091] In addition, in the cooler C2 of the second embodiment described above, in the case where two or more of the first coolant circuits 3 are provided, the first coolant circuits 3 are connected in parallel to each other with respect to the circuit configuration portion formed by connecting the refrigerant circuit portion 5a including the first expansion valve 77 and the third expansion valve 80 to each other through the first heat exchanger 6. In addition, in the case where two or more of the second coolant circuits 4 are provided, the second coolant circuits 4 are connected in parallel to each other with respect to the circuit configuration portion formed by connecting the refrigerant circuit portion 5b including the second expansion valve 78 and the fourth expansion valve 82 to each other through the second heat exchanger 7.

[0092] BRIEF DESCRIPTION OF DRAWINGS

[0093] C1, C2 coolers

[0094] W1 first load

[0095] W2 second load

[0096] 1 tank

[0097] 2 pump

[0098] 3 first coolant circuit

[0099] 4 second coolant circuit

[0100] 5, 5A refrigeration circuit

[0101] 6 first heat exchanger

[0102] 6a, 6c inlet

[0103] 6b, 6d outlet

[0104] 7 second heat exchanger

[0105] 7a, 7c inlet

[0106] 7b, 7d outlet

[0107] 8 control device

[0108] 15, 70 compressor

[0109] 15a, 70a outlet

[0110] 15b, 70b inlet

[0111] 16, 71 condenser

[0112] 16a, 71a inlet

[0113] 16b, 71b outlet

[0114] 21, 72 first refrigerant line

[0115] 22, 73 second refrigerant line

[0116] 23, 74 third refrigerant line

[0117] 24, 75 fourth refrigerant line

[0118] 25, 76 fifth refrigerant line

[0119] 26, 79 sixth refrigerant line

[0120] 27, 77 first expansion valve

[0121] 28, 78 second expansion valve

[0122] 29, 80 third expansion valve

[0123] 40 first supply line

[0124] 41 first return line

[0125] 50 branch line

[0126] 51 second supply line

[0127] 52 second return line

[0128] 54 pressure regulating valve

[0129] 60 filter line

[0130] 61 DI filter

[0131] 62 solenoid valve

[0132] 63 DI sensor

[0133] 81 seventh refrigerant line

[0134] 82 fourth expansion valve

Claims

1. A chiller characterized by comprising: a tank that accommodates a coolant; a pump that discharges the coolant in the tank; a plurality of coolant circuits that branch the coolant discharged by the pump and supply the coolant to a plurality of loads, respectively; and a refrigeration circuit that adjusts a temperature of the coolant by heat exchange between the coolant and a refrigerant, the plurality of coolant circuits and the refrigeration circuit are connected to each other via individual heat exchangers that can control a heat exchange capacity, respectively, the plurality of coolant circuits include a first coolant circuit that cools a first load and a second coolant circuit that cools a second load whose temperature is different from that of the first load, a first heat exchanger that connects the first coolant circuit and the refrigeration circuit adjusts a temperature of the coolant returned from the first load and the second load to the tank, a second heat exchanger that connects the second coolant circuit and the refrigeration circuit adjusts a temperature of the coolant supplied from the tank to the second load.

2. The chiller according to claim 1, characterized in that the first coolant circuit includes a first supply line that delivers the coolant discharged from the pump to the first load in a state where a temperature in the tank, that is, a first set temperature is maintained, and a first return line that returns the coolant from the first load to the tank, the first heat exchanger being connected to the first return line, whereby the coolant of the first return line flows into the tank after being adjusted to the first set temperature in the first heat exchanger, the second coolant circuit includes a branch line that branches from the first supply line and is connected to the second heat exchanger, a second supply line that delivers the coolant adjusted to a second set temperature in the second heat exchanger to the second load, and a second return line that returns the coolant from the second load to the tank, the second return line being connected to the first return line, whereby the coolant of the second return line merges with the coolant of the first return line.

3. The chiller according to claim 2, characterized in that a pressure adjustment valve that makes a pressure of the coolant flowing in the second coolant circuit different from a pressure of the coolant flowing in the first coolant circuit is connected to the second supply line.

4. The chiller according to claim 2 or 3, characterized in that a filter line that connects the first supply line and the first return line is provided in the first coolant circuit, a DI filter that adjusts an electric conductivity of the coolant and a solenoid valve that opens and closes the filter line are connected to the filter line, a DI sensor that measures the electric conductivity of the coolant flowing in the first return line to open and close the solenoid valve is connected to the first return line.

5. The chiller according to claim 4, characterized in that the filter line connects a position of the first supply line closer to the first load than a position where the branch line branches and a position of the first return line closer to the first heat exchanger than a position where the second return line merges. ​ 6. The cooler according to claim 1, wherein the refrigerant circuit has a first refrigerant line connecting the outlet of the compressor and the inlet of the condenser, a second refrigerant line connecting the outlet of the condenser and the inlet of the first heat exchanger, a third refrigerant line connecting the outlet of the first heat exchanger and the inlet of the compressor, a fourth refrigerant line connecting the first refrigerant line and the inlet of the second heat exchanger, a fifth refrigerant line connecting the outlet of the second heat exchanger and the inlet of the first heat exchanger, and a sixth refrigerant line connecting the fourth refrigerant line and the fifth refrigerant line, a first expansion valve is connected to the second refrigerant line, a second expansion valve is connected to the fifth refrigerant line, and a third expansion valve is connected to the sixth refrigerant line.

7. The cooler according to claim 1, wherein the refrigerant circuit has a first refrigerant line connecting the outlet of the compressor and the inlet of the condenser, a second refrigerant line connecting the outlet of the condenser and the inlet of the first heat exchanger, a third refrigerant line connecting the second refrigerant line and the inlet of the second heat exchanger, a fourth refrigerant line connecting the outlet of the first heat exchanger and the inlet of the compressor, a fifth refrigerant line connecting the outlet of the second heat exchanger and the fourth refrigerant line, a sixth refrigerant line branching from the first refrigerant line and connecting the inlet of the first heat exchanger, and a seventh refrigerant line branching from the sixth refrigerant line and connecting the inlet of the second heat exchanger, a first expansion valve is connected to the second refrigerant line, a second expansion valve is connected to the third refrigerant line, a third expansion valve is connected to the sixth refrigerant line, and a fourth expansion valve is connected to the seventh refrigerant line.

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