Heater, and liquid temperature adjustment device comprising the same

Abstract

To provide a heater capable of preventing dry-heating of a heating body and stopping heating by the heating body at an appropriate timing even in a state where liquid is not circulating, and a liquid temperature adjustment device comprising the heater.SOLUTION: A heater 21 includes: a case 23; a heating body 24 housed in the case 23; a flow inlet temperature measurement instrument 26; a heating body temperature measurement instrument 27; a flow outlet temperature measurement instrument 28; and an operation control unit 80. The operation control unit 80 calculates a flow inlet temperature change amount ΔT1, a heating body temperature change amount ΔT2, and a flow outlet temperature change amount ΔT3, during a preset measurement temperature change amount calculation time. When a state where the flow inlet temperature change amount ΔT1 is smaller than a first threshold value TS1 for determining dry heating, the heating body temperature change amount ΔT2 is larger than a second threshold value TS2 for determining dry heating, and the flow outlet temperature change amount ΔT3 is smaller than a third threshold value TS3 for determining dry heating continues for a reference period of time, the operation control unit 80 executes processing to turn off the heating by the heating body 24.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heater and a liquid temperature adjustment device having the heater. [Background technology]

[0002] An example of a heater for heating a refrigerant is the heater (heating heater) used in a humidifier disclosed in Patent Document 1 (JP 2017-116164 A). The heater disclosed in Patent Document 1 is equipped with a temperature thermistor that detects the temperature of water heated by the heater in a water storage chamber, and by calculating the temperature gradient of this temperature thermistor before and after a certain period of time, the presence or amount of water in the water storage chamber is detected, and the on / off of heating by the heater is controlled to prevent the heater from running dry. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-116164 A (Claim 1, etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] In a liquid temperature control device that circulates a liquid by adjusting the temperature of the liquid and supplying it to an object, and then adjusting the temperature of the liquid that returns from the object and supplying it back to the object, the temperature of the returning liquid fluctuates depending on the load on the object. For this reason, a configuration that controls the on / off of heating by a heater (heating element) based solely on the temperature gradient of the heater (heating element), as in the configuration disclosed in Patent Document 1, has the problem of being unable to distinguish between a temperature rise that occurs when the load on the object is removed and a temperature rise that occurs when the heating element is running dry. Another problem is that it is unable to meet the need to stop heating from the heating element even when the liquid is not circulating (when the liquid is stagnant). [Means for solving the problem]

[0005] The present invention is therefore intended to solve the above problems, and has the following objectives: To provide a heater that can appropriately switch heating by the heating element on and off by checking temperature changes at the liquid inlet and outlet and at the position where the heating element is installed, thereby preventing the heating element from running dry, and that can stop heating by the heating element at the appropriate time even when liquid is not circulating, and a liquid temperature control device having the heater.

[0006] As a result of intensive research by the inventors to solve the above problems, the inventors have come up with the following configuration: That is, the present invention comprises a case formed with an inlet and an outlet for a liquid, a heating element housed in the case, an inlet temperature measuring device for measuring the temperature at the inlet, a heating element temperature measuring device for measuring the temperature of the heating element, an outlet temperature measuring device for measuring the temperature at the outlet, and an operation control unit, wherein the operation control unit calculates an inlet temperature change amount which is the amount of change in the inlet temperature measured by the inlet temperature measuring device during a preset measured temperature change amount calculation time, and a heating element temperature change amount which is the amount of change in the heating element temperature measured by the heating element temperature measuring device during the measured temperature change amount calculation time. and an outlet temperature change amount, which is the amount of change in the outlet temperature measured by the outlet temperature measuring device during the measured temperature change amount calculation time, and if a state in which the inlet temperature change amount is smaller than a predetermined first threshold for determining whether the heater is running dry, the heating element temperature change amount is larger than a predetermined second threshold for determining whether the heater is running dry, and the outlet temperature change amount is smaller than a predetermined third threshold for determining whether the heater is running dry continues for a predetermined reference time, a process is executed to turn off the heating element.

[0007] This allows for proper on / off switching of heating by the heating element by checking temperature changes at the liquid inlet and outlet and at the location of the heating element, preventing the heating element from running dry. It also makes it possible to stop heating by the heating element at the appropriate time even when liquid is not circulating.

[0008] The heating element temperature measuring device is also characterized in that it is disposed in a protective tube attached to the case so that a tip thereof is positioned close to the heating element.

[0009] This allows the heating element temperature measuring device to be positioned close to the heating element inside the case without the liquid leaking from the case, even when a liquid with low viscosity that easily leaks even from a small gap is used.

[0010] There is also an invention for a liquid temperature control device comprising a liquid circulation path for circulating a liquid, a heater arranged on the path of the liquid circulation path and heating the liquid, a cooler arranged on the path of the liquid circulation path and cooling the liquid, and a temperature control unit arranged on the path of the liquid circulation path, wherein the heater is a heater according to the present invention.

[0011] This prevents the heating element in the heater in the liquid temperature adjustment device from running dry, making it possible to provide a safe liquid temperature adjustment device. [Effects of the Invention]

[0012] According to the configuration of the present invention, by checking the temperature changes at the liquid inlet and outlet and at the position where the heating element is disposed, it is possible to appropriately switch on and off heating by the heating element of the heater, prevent the heating element from running dry, and provide a heater that can stop heating by the heating element at an appropriate time even when liquid is not circulating.Furthermore, it is possible to provide a safe liquid temperature control device by preventing the heating element in the heater from running dry. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic configuration diagram of a liquid temperature adjustment device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a detailed view of the heater in FIG. [Figure 3]10 is an explanatory diagram showing the correspondence between the inlet temperature change amount, the heating element temperature change amount, and the outlet temperature change amount and the operating state of the heater. FIG. [Figure 4] 4 is a graph showing an example of the relationship between the inlet temperature measurement value, the heating element temperature measurement value, the outlet temperature measurement value and the elapsed time in State 1 in FIG. 3. [Figure 5] 4 is a graph showing an example of the relationship between the inlet temperature measurement value, the heating element temperature measurement value, the outlet temperature measurement value and the elapsed time in State 2 in FIG. 3. [Figure 6] 4 is a graph showing an example of the relationship between the inlet temperature measurement value, the heating element temperature measurement value, the outlet temperature measurement value, and the elapsed time in State 3 in FIG. 3. [Figure 7] 4 is a graph showing an example of the relationship between the inlet temperature measurement value, the heating element temperature measurement value, the outlet temperature measurement value and the elapsed time in State 4 in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1 is a schematic diagram of a liquid temperature adjustment device 100 according to this embodiment. The liquid temperature adjustment device 100 includes a refrigerant circulation path 20 as a liquid circulation path, a temperature adjustment unit 40, a cooling water supply unit 60, an operation control unit 80, and an alarm 90. Here, a fluorine-based coolant is used as the refrigerant circulated through the refrigerant circulation path 20, but the liquid whose temperature is to be adjusted by the liquid temperature adjustment device 100 is not limited to a fluorine-based coolant.

[0015] Coolant circulation path 20 has heater 21, cooler 22, and temperature adjustment unit 40 on its path. Coolant circulation path 20 heats a fluorine-based coolant with heater 21 or cools it with cooler 22, or heats the fluorine-based coolant with heater 21 and cools it with cooler 22, and circulates and supplies the fluorine-based coolant between it and temperature adjustment unit 40. Note that an example of temperature adjustment unit 40 is a semiconductor manufacturing device. The operations of heater 21 and cooler 22 are controlled by operation control unit 80.

[0016] The cooling water supply unit 60 has an adjustment valve 61 and a supply path 62 that supplies cooling liquid to the cooler 22 disposed in the refrigerant circulation path 20. An operation control unit 80 controls the opening and closing of the adjustment valve 61, thereby controlling the operation of each of the coolers 22. A known method can be used for controlling the operation of the cooler 22 by the cooling water supply unit 60, and therefore detailed description thereof will be omitted here.

[0017] The operation control unit 80 has a storage unit 82, typically a non-volatile memory, and a calculation unit 84, typically a CPU. An operation control program is stored in advance in the storage unit 82, and the calculation unit 84 operates in accordance with the operation control program to control the operation of the liquid temperature adjustment device 100. Such an operation control unit 80 can employ a known configuration, and therefore a detailed description thereof will be omitted here.

[0018] The heater 21 will be described in detail below with reference to Fig. 2. The heater 21 includes a case 23, a heating element 24, and a temperature measuring device 25. In this embodiment, the heater 21 flows through a refrigerant circulation path 20 connected by an inlet path 23A and an outlet path 23C, and a fluorine-based coolant is circulated between the heater 21 and the temperature adjustment unit 40.

[0019] Case 23 of heater 21 is formed with inlet 23B for introducing the fluorine-based coolant that has returned from temperature adjustment unit 40 via inlet path 23A, and outlet 23D for discharging the fluorine-based coolant downstream of heater 21. As shown in Fig. 2, case 23 is formed in a substantially rectangular (cuboid) shape in a plan view to accommodate long heating element 24. Inlet 23B and outlet 23D are preferably disposed on diagonal positions of case 23 so that the distance between them in the internal space of case 23 is as long as possible.

[0020] Electric power is supplied to the heating element 24 from a commercial power source. The supply of power to the heating element 24 is controlled by an operation control unit 80. In this embodiment, the heating element 24 is disposed in the center of the internal space of the case 23 so as to be located midway between the inlet 23B and the outlet 23D.

[0021] The temperature measuring device 25 in the heater 21 includes an inlet temperature measuring device 26, a heating element temperature measuring device 27, and an outlet temperature measuring device 28. The inlet temperature measuring device 26 is disposed at the inlet 23B, measures the temperature at the inlet 23B, and transmits the measured inlet temperature value to the operation control unit 80. The heating element temperature measuring device 27 is disposed in a protective tube 23E attached to the case 23 so that its tip is located close to the heating element 24. The heating element temperature measuring device 27 measures the temperature of the heating element 24 and transmits the measured heating element temperature value to the operation control unit 80. The outlet temperature measuring device 28 is disposed at the outlet 23D, measures the temperature at the outlet 23D, and transmits the measured outlet temperature value to the operation control unit 80.

[0022] A memory unit 82 of the operation control unit 80 pre-stores a first threshold value TS1 for determining whether the boil-dry condition is running, a second threshold value TS2 for determining whether the boil-dry condition is running, a third threshold value TS3 for determining whether the boil-dry condition is running, a measured temperature change calculation time, and a reference time (a preset reference time) for determining whether the boil-dry condition is running. The memory unit 82 also stores the inlet temperature measurement value, the heating element temperature measurement value, and the outlet temperature measurement value transmitted from the inlet temperature measuring device 26, the heating element temperature measuring device 27, and the outlet temperature measuring device 28. The calculation unit 84 calculates, for the inlet temperature measurement value, the heating element temperature measurement value, and the outlet temperature measurement value, an inlet temperature change amount ΔT1, which is the amount of change in the inlet temperature measurement value at the measured temperature change amount calculation time; a heating element temperature change amount ΔT2, which is the amount of change in the heating element temperature measurement value at the measured temperature change amount calculation time; and an outlet temperature change amount ΔT3, which is the amount of change in the outlet temperature measurement value at the measured temperature change amount calculation time. The inlet temperature change amount ΔT1, the heating element temperature change amount ΔT2, and the outlet temperature change amount ΔT3 calculated by the calculation unit 84 are stored in the storage unit 82, respectively.

[0023] Furthermore, while the heater 21 is operating (power is being supplied to the heating element 24), the calculation unit 84 determines whether the heating element 24 is in dry-heating mode based on the inlet temperature change amount ΔT1, the heating element temperature change amount ΔT2, the outlet temperature change amount ΔT3, and the reference time for dry-heating determination. If the calculation unit 84 determines that the heating element 24 is in dry-heating mode, it executes a process of stopping the supply of power to the heating element 24 and turning off heating by the heating element 24.

[0024] The alarm device 90 issues an alarm in a known manner in response to instructions from the operation control unit 80. A speaker can be used as an example of the alarm device 90, but the specific form of the alarm device 90 is not particularly limited.

[0025] Next, the processing executed by the operation control unit 80 when the temperature of the refrigerant circulating through the refrigerant circulation path 20 is set to 90°C by the temperature adjustment unit 40 will be described with reference to Figs. 3 to 7. Fig. 3 is an explanatory diagram showing the inlet temperature change ΔT1, the heating element temperature change ΔT2, and the outlet temperature change ΔT3, and the operating state of the heater 21. Next, the correspondence between the inlet temperature change ΔT1, the heating element temperature change ΔT2, and the outlet temperature change ΔT3 shown in Fig. 3 and the operating state of the heater 21 will be described.

[0026] In State 1 in FIG. 3, the inlet temperature change ΔT1 is smaller than the first threshold value TS1 for determining whether the heater 21 is running dry, the heating element temperature change ΔT2 is smaller than the second threshold value TS2 for determining whether the heater 21 is running dry, and the outlet temperature change ΔT3 is smaller than the third threshold value TS3 for determining whether the heater 21 is running dry. State 1, as shown in FIG. 4, is a state in which the heater 21 is operating under a constant cooling load from the temperature adjustment unit 40. Specifically, a fluorine-based coolant flows through the refrigerant circuit 20, and the fluorine-based coolant returns after a constant temperature drop due to the constant cooling load from the temperature adjustment unit 40. The fluorine-based coolant is then heated by the heating element 24, and the inlet temperature change ΔT1, the heating element temperature change ΔT2, and the outlet temperature change ΔT3 are all small. Since State 1 does not correspond to whether the heater 24 is running dry, the operation control unit 80 executes a process to continue supplying power to the heater 24 (a process to continue heating by the heater 24).

[0027] 3, the inlet temperature change ΔT1 is smaller than the first threshold value TS1 for determining whether the refrigerant is running dry, the heating element temperature change ΔT2 is greater than the second threshold value TS2 for determining whether the refrigerant is running dry, and the outlet temperature change ΔT3 is greater than the third threshold value TS3 for determining whether the refrigerant is running dry. This state 2, as shown in FIG. 5, is a state in which the heater 21 is operating to raise the temperature of the fluorine-based coolant to the set temperature (90°C) when the liquid temperature adjustment device 100 starts operating. Specifically, the fluorine-based coolant flows through the refrigerant circulation path 20 and is heated by the heating element 24 to raise the temperature of the fluorine-based coolant from a cold state (room temperature: 20°C). The inlet temperature change ΔT1 is small, but the heating by the heating element 24 results in large changes in the heating element temperature ΔT2 and the outlet temperature change ΔT3. Since it can be determined that such a state 2 does not correspond to empty heating of the heating element 24, the operation control unit 80 executes a process to continue supplying power to the heating element 24.

[0028] In addition, in State 3 in FIG. 3 , the inlet temperature change ΔT1 is greater than the first threshold value TS1 for determining whether the heater 21 is running dry, the heating element temperature change ΔT2 is greater than the second threshold value TS2 for determining whether the heater 21 is running dry, and the outlet temperature change ΔT3 is less than the third threshold value TS3 for determining whether the heater 21 is running dry. State 3, as shown in FIG. 6 , is a state in which the heater 21 is operating when a temporary cooling load is applied by the temperature adjustment unit 40. Specifically, fluorine-based coolant flows through the refrigerant circuit 20, and the fluorine-based coolant returns after its temperature has temporarily dropped due to the temporary cooling load of the temperature adjustment unit 40. The heating element 24 heats the fluorine-based coolant. Because the load fluctuates, the inlet temperature change ΔT1 and the heating element temperature change ΔT2 are large, while the outlet temperature change ΔT3 is small because of heating by the heating element 24. Since State 3 does not correspond to dry-heating of the heating element 24, the operation control unit 80 executes a process to continue supplying power to the heating element 24.

[0029] 3, the inlet temperature change ΔT1 is smaller than the first threshold value TS1 for determining whether the heater is running dry, the heating element temperature change ΔT2 is larger than the second threshold value TS2 for determining whether the heater is running dry, and the outlet temperature change ΔT3 is smaller than the third threshold value TS3 for determining whether the heater is running dry. State 4 indicates that the heater 21 is operating under inappropriate conditions. Specifically, this is a state in which the heating element 24 is generating heat when there is no fluorine-based coolant in the case 23, or when there is fluorine-based coolant in the case 23 but it is not circulating. Therefore, as shown in FIG. 7, the heating element temperature change ΔT2 is large, and the inlet temperature change ΔT1 and the outlet temperature change ΔT3 are small.

[0030] When State 4 is detected, the operation control unit 80 then checks whether State 4 continues for the reference time for determining whether the heater is running dry (here, the reference time is set to 10 seconds). If State 4 continues for the reference time for determining whether the heater is running dry, the operation control unit 80 determines that the heating element 24 of the heater 21 is in a running dry state. The operation control unit 80 then stops the supply of power to the heating element 24 and executes processing to turn off heating by the heating element 24. Here, the reference time for determining whether the heater is running dry is set to 10 seconds, but the reference time for determining whether the heater is running dry is not limited to 10 seconds and can be set to any time. The operation control unit 80 can also execute processing to cause the alarm 90 to output an alarm sound to notify the user that the heater is in a running dry state.

[0031] In this way, whether or not the heating element 24 is running dry can be reliably determined based on whether or not a state in which the heating element 24 is likely to be running dry continues for a preset reference time based on the relationship between the inlet temperature change ΔT1 and the first threshold value TS1 for determining dry heating, the relationship between the heating element temperature change ΔT2 and the second threshold value TS2 for determining dry heating, and the relationship between the outlet temperature change ΔT3 and the third threshold value TS3 for determining dry heating. Furthermore, by reliably determining whether or not the heating element 24 is running dry, shutdowns of related equipment such as the liquid temperature control device 100 due to false detection of dry heating can be eliminated, contributing to improved productivity. Note that when the heater 21 is operating (power is being supplied to the heating element 24), any of the following states, State 1, State 2, or State 3, is considered normal.

[0032] Furthermore, by accurately determining whether or not heating element 24 is running dry and controlling the on / off of heating by heating element 24, it is possible to prevent the generation of hydrogen fluoride due to thermal decomposition of the fluorine-based coolant. Furthermore, if a thermal insulating material (not shown) is provided to insulate case 23, the temperature will not exceed the heat resistance temperature of the insulating material, thereby preventing smoke from being generated due to melting of the insulating material, etc. Furthermore, as shown in Figure 7, heating by heating element 24 is stopped at a timing when the temperature of heating element 24 has a sufficient margin above the allowable temperature, so even if the temperature of heating element 24 rises after heating is stopped, it is possible to reliably prevent the generation of hydrogen fluoride and the melting of the insulating material.

[0033] In the above embodiment, a refrigerant that leaks easily even through a small gap is used, so an example is shown in which the inlet temperature measuring device 26 and the outlet temperature measuring device 28 are attached to the outer surface of the case 23, and the heating element temperature measuring device 27 is disposed in the protective tube 23E attached to the case 23, but this is not limiting. If a refrigerant that does not leak easily is used, the inlet temperature measuring device 26, the heating element temperature measuring device 27, and the outlet temperature measuring device 28 can be disposed directly inside the case 23 or screwed in from the outside of the case 23 (measures to prevent refrigerant leakage from the screwed parts are implemented), and a configuration can be adopted in which the temperatures of the fluorine-based coolant and the heating element 24 are measured directly.

[0034] In addition, the values ​​of the first threshold value TS1 for determining whether the inlet temperature measuring device 26, the heating element temperature measuring device 27, and the outlet temperature measuring device 28 are changed appropriately depending on the installation positions (indirect temperature measurement or direct temperature measurement) of the case 23 and the case 23.

[0035] Furthermore, it is also possible to adopt a configuration in which the measured values ​​of the inlet temperature measuring instrument 26, the heating element temperature measuring instrument 27, and the outlet temperature measuring instrument 28 are transmitted to the operation control unit 80 by wireless communication.

[0036] In the above embodiment, the operating state of the temperature adjustment unit 40 and the presence or absence of a fluorine-based coolant in the internal space of the case 23 are determined based on the relationship between the inlet temperature change ΔT1 and the first threshold value TS1 for determining dry-burn, the relationship between the heating element temperature change ΔT2 and the second threshold value TS2 for determining dry-burn, and the relationship between the outlet temperature change ΔT3 and the third threshold value TS3 for determining dry-burn. However, the present invention is not limited to this configuration. Specifically, in the above embodiment, the first threshold value TS1 for determining dry-burn, the second threshold value TS2 for determining dry-burn, and the third threshold value TS3 for determining dry-burn are pre-stored in the memory unit 82. However, the first threshold value TS1 for determining dry-burn and the third threshold value TS3 for determining dry-burn can be set to the same value. Furthermore, if the first threshold value TS1 for determining dry-burn, the second threshold value TS2 for determining dry-burn, and the third threshold value TS3 for determining dry-burn can be set to the same value, a configuration in which only the dry-burn determination thresholds are stored in the memory unit 82 can also be employed.

[0037] In addition, in the above embodiment, the set temperature of the liquid fluorine-based coolant is 90°C, but the present invention is not limited to this embodiment. The set temperature of the liquid fluorine-based coolant is not limited to 90°C, and can be set to any temperature.

[0038] Furthermore, the liquid temperature adjustment device 100 of the present invention is exemplified as having a heater 21 and a cooler 22, and a refrigerant circulation path 20 that circulates a fluorine-based coolant between the heater 21, the cooler 22, and the temperature adjustment unit 40, but a form having multiple refrigerant circulation paths 20 in different temperature ranges can also be adopted.

[0039] In the above embodiment, the cooler 22 that cools the refrigerant is exemplified as being supplied with cooling water from the cooling water supply unit 60, but the cooler 22 in the present invention is not limited to this form. It is also possible to adopt a form in which an evaporator of a refrigeration cycle is applied to the cooler 22, or a form in which a blower fan is applied to the cooler 22.

[0040] Furthermore, in addition to being applied to the heater 21 or the liquid temperature control device 100, the present invention can further enhance safety by adopting a form in which it is used in combination with other safety devices (a flow switch that detects the flow of refrigerant or an interlock for the refrigerant pump (neither of which are shown)).

[0041] In addition to the modifications described above, it is also possible to adopt a form in which the modifications described in the embodiment are appropriately combined. [Explanation of symbols]

[0042] 20: Refrigerant circulation path (liquid circulation path) 21: heater, 22: cooler, 23: case, 23A: inlet path, 23B: inlet, 23C: Delivery path, 23D: Outlet, 23E: Protective tube, 24: Heating element, 25: Temperature measuring instrument, 26: Inlet temperature measuring instrument, 27: Heating element temperature measuring instrument, 28: Outlet temperature measuring instrument 40: Temperature adjustment section 60: Cooling water supply section 61: Regulating valve, 62: Supply line 80: Operation control unit 82: Storage section, 84: Arithmetic section 90:Alarm 100:Liquid temperature controller TS1: First threshold for determining whether the engine is running dry, TS2: Second threshold for determining whether the engine is running dry, TS3: Third threshold for determining dry firing ΔT1: inlet temperature change, ΔT2: heating element temperature change, ΔT3: Outlet temperature change

Claims

1. The device comprises a case having a refrigerant inlet and outlet formed therein, a heating element housed in the case, an inlet temperature measuring device for measuring the temperature at the inlet, a heating element temperature measuring device for measuring the temperature of the heating element, an outlet temperature measuring device for measuring the temperature at the outlet, and an operation control unit, The operation control unit an inlet temperature change amount, which is the amount of change in the inlet temperature measured by the inlet temperature measuring device during a predetermined measured temperature change amount calculation time; a heating element temperature change amount, which is the amount of change in the heating element temperature measured by the heating element temperature measuring device during the measured temperature change amount calculation time; and an outlet temperature change amount, which is the amount of change in the outlet temperature measured by the outlet temperature measuring device during the measured temperature change amount calculation time; A heater characterized in that, when a state in which the amount of change in the inlet temperature is smaller than a predetermined first threshold for determining whether the heater is running dry, the amount of change in the heating element temperature is larger than a predetermined second threshold for determining whether the heater is running dry, and the amount of change in the outlet temperature is smaller than a predetermined third threshold for determining whether the heater is running dry continues for a predetermined reference time, a process is executed to turn off heating by the heating element.

2. 2. The heater according to claim 1, wherein the heating element temperature measuring device is disposed in a protective tube attached to the case so that a tip of the heating element temperature measuring device is located close to the heating element.

3. a liquid circulation path for circulating the liquid; a heater disposed on the liquid circulation path for heating the liquid; a cooler disposed on the liquid circulation path and configured to cool the liquid; a temperature adjusting unit disposed on the liquid circulation path, 3. A liquid temperature control device, wherein the heater according to claim 1 or 2 is used as the heater.

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