Cooling system and cooling method

Abstract

The present invention provides a cooling system and cooling method that can suppress blockage of the path through which the fluid to be cooled flows, even when the fluid to be cooled is cooled by heat exchange with a cold source fluid at a temperature lower than the freezing point of the fluid to be cooled. [Solution] The cooling system according to the present invention comprises: a first path through which a fluid to be cooled flows; a second path through which a cold source fluid flows; a heat exchange unit that cools the fluid to be cooled by performing heat exchange between the fluid to be cooled flowing through the first path and the cold source fluid flowing through the second path; a temperature measuring unit that measures the temperature of the cold source fluid during the heat exchange with the fluid to be cooled in the heat exchange unit, and after the heat exchange with the fluid to be cooled in the heat exchange unit, or both; a flow rate adjustment unit that can adjust the amount of cold source fluid supplied to the heat exchange unit; and a heating unit that can heat the heat exchange unit, or both.

Description

Technical Field

[0001] The present invention relates to a cooling system and a cooling method.

Background Art

[0002] Conventionally, a cooling device that cools a coolant by heat exchange with a refrigerant gas is known. Patent Document 1 discloses this type of cooling device.

[0003] The cooling device of Patent Document 1 includes a turbo compressor that compresses and circulates a refrigerant gas, a main heat exchanger that cools the compressed refrigerant gas by heat exchange with the return refrigerant gas, an expansion turbine that adiabatically expands the cooled refrigerant gas, a sub heat exchanger that exchanges heat between the cryogenic refrigerant gas exiting the expansion turbine and the coolant, a circulation pump that circulates the coolant between the sub heat exchanger and the object to be cooled, temperature measuring means for measuring the temperature of the coolant, a first closed flow path that constitutes a circulation path for circulating the refrigerant gas after heat exchange in the sub heat exchanger to the turbo compressor via the main heat exchanger, and a second closed flow path that constitutes a circulation path for circulating the coolant after heat exchange in the sub heat exchanger by the circulation pump.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a cooling device as described in Patent Document 1 is used to cool a fluid to be cooled by heat exchange with a cold source fluid at a temperature lower than the freezing point of the fluid to be cooled, freezing of the fluid to be cooled may occur. In this case, if the freezing of the fluid to be cooled is local, the operation of the device can be continued, but if the freezing of the fluid to be cooled progresses, the path through which the fluid to be cooled flows may be blocked, and there is a risk that the operation of the cooling device cannot be continued.

[0006] The present invention aims to provide a cooling system and a cooling method that can suppress blockage of the path through which the fluid to be cooled flows, even when the fluid to be cooled is cooled by heat exchange with a cold source fluid at a temperature lower than the freezing point of the fluid to be cooled. [Means for solving the problem]

[0007] A cooling system as a first aspect of the present invention is: (1) The first path through which the fluid to be cooled flows, The second pathway through which the cold source fluid flows, A heat exchange unit that cools the fluid to be cooled by performing heat exchange between the fluid to be cooled flowing through the first path and the cold source fluid flowing through the second path, A temperature measuring unit that measures the temperature of the cold source fluid during the heat exchange with the fluid to be cooled in the heat exchange unit, and after the heat exchange with the fluid to be cooled in the heat exchange unit, or both of these times, The cooling system comprises one or both of the following: a flow rate adjustment unit capable of adjusting the amount of the cold source fluid supplied to the heat exchange unit, and a heating unit capable of heating the heat exchange unit.

[0008] A cooling system as one embodiment of the present invention is (2) The heat exchange section comprises a plurality of heat exchangers arranged in series along the first path and the second path, The temperature measuring unit measures the temperature of the cold source fluid after heat exchange has been performed with the cooled fluid in at least one of the plurality of heat exchangers, and is the cooling system described in (1) above.

[0009] A cooling method as a second aspect of the present invention is: (3) A cooling method using the cooling system described in (1) or (2) above, The cooling method involves adjusting the amount of the cold source fluid supplied to the heat exchange section by the flow rate adjustment section and heating the heat exchange section by the heating section, or both, according to the temperature of the cold source fluid measured by the temperature measurement section. [Effects of the Invention]

[0010] According to the present invention, even when the fluid to be cooled is cooled by heat exchange with a cold source fluid at a temperature lower than the freezing point of the fluid to be cooled, it is possible to provide a cooling system and a cooling method that can suppress blockage of the path through which the fluid to be cooled flows. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a cooling system as one embodiment of the present invention. [Figure 2] This graph shows an example of the temperature change of each fluid when heat exchange is performed between the fluid to be cooled and the cold source fluid using the cooling system shown in Figure 1. [Figure 3] This figure shows a cooling system as one embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the cooling system and cooling method according to the present invention will be illustrated with reference to the drawings. In each figure, identical components are denoted by the same reference numerals.

[0013] <First Embodiment> Figure 1 shows the configuration of a cooling system 1 as one embodiment of the cooling system according to the present invention. As shown in Figure 1, the cooling system 1 of this embodiment includes a first path 2, a second path 3, a heat exchange unit 4, a temperature measuring unit 5, a flow rate adjustment unit 6, a heating unit 7, and a control unit 8.

[0014] The cooled fluid flows through the first path 2. The cooled fluid may be a gas, a liquid, or a composite of a gas and a liquid. Examples of the components of the cooled fluid include methane, natural gas, air, nitrogen, oxygen, argon, neon, hydrogen, helium, etc. The cooled fluid may be pumped through the first path 2 by, for example, a pump or the like.

[0015] The cold source fluid flows through the second path 3. The cold source fluid may be a gas, a liquid, or a composite of a gas and a liquid. The temperature of the cold source fluid is lower than the temperature of the cooled fluid. Also, the temperature of the cold source fluid in this embodiment is lower than the freezing point of the cooled fluid. The cold source fluid is not particularly limited. For example, when the cooled fluid is methane gas, it can be liquid nitrogen. Also, when the cooled fluid is liquid nitrogen, the cold source fluid can be, for example, liquid hydrogen or liquid helium. The cold source fluid may be pumped through the second path 3 by, for example, a pump or the like.

[0016] The heat exchange unit 4 cools the cooled fluid by performing heat exchange between the cooled fluid flowing through the first path 2 and the cold source fluid flowing through the second path 3. The heat exchange unit 4 in this embodiment is a plate fin type heat exchanger. By configuring the heat exchange unit 4 as a plate fin type heat exchanger, heat exchange can be performed efficiently, and miniaturization of the heat exchange unit 4 can be achieved. However, the heat exchanger constituting the heat exchange unit 4 is not limited to this, and for example, a shell and tube type heat exchanger or the like may be used.

[0017] As shown in FIG. 1, in this embodiment, in the heat exchange unit 4, the cooled fluid and the cold source fluid flow in the same direction as each other. That is, in this embodiment, heat exchange is performed in a so-called co-current manner. However, in the heat exchange unit 4, the cooled fluid and the cold source fluid may flow in opposite directions to each other. That is, heat exchange may be performed in a so-called counter-current manner. Whether to perform heat exchange in a co-current manner or a counter-current manner may be appropriately selected according to the configuration of the heat exchange unit 4 and the like.

[0018] The temperature measurement unit 5 of the present embodiment measures the temperature of the cold source fluid after heat exchange with the fluid to be cooled in the heat exchange unit 4. In other words, the temperature measurement unit 5 of the present embodiment measures the outlet temperature of the cold source fluid in the heat exchange unit 4. The temperature measurement unit 5 of the present embodiment is a thermometer provided in the second path 3. As shown in FIG. 1, this thermometer is provided on the downstream side of the heat exchange unit 4 in the second path 3. The type of thermometer is not particularly limited, and for example, it may be a liquid thermometer, a thermocouple thermometer, or the like.

[0019] The temperature measurement unit 5 may be configured to measure the temperature of the cold source fluid while heat exchange with the fluid to be cooled is being performed in the heat exchange unit 4. In this case, the temperature measurement unit 5 may be configured to be incorporated inside the heat exchanger constituting the heat exchange unit 4. Further, the temperature measurement unit 5 may be configured to measure the temperature of the cold source fluid both while heat exchange with the fluid to be cooled is being performed in the heat exchange unit 4 and after heat exchange with the fluid to be cooled in the heat exchange unit 4. That is, the temperature measurement unit 5 may be configured to measure the temperature of one or both of the cold source fluids while heat exchange with the fluid to be cooled is being performed in the heat exchange unit 4 and after heat exchange with the fluid to be cooled in the heat exchange unit 4.

[0020] The flow rate adjustment unit 6 can adjust the supply amount of the cold source fluid to the heat exchange unit 4. More specifically, the flow rate adjustment unit 6 of the present embodiment is provided in the second path 3 and can adjust the supply amount of the cold source fluid to the heat exchange unit 4 by increasing or decreasing the flow rate of the cold source fluid flowing through the second path 3. As shown in FIG. 1, the flow rate adjustment unit 6 of the present embodiment is provided on the upstream side of the heat exchange unit 4 in the second path 3. However, the flow rate adjustment unit 6 only needs to be able to adjust the supply amount of the cold source fluid to the heat exchange unit 4, and may be provided on the downstream side of the heat exchange unit 4 in the second path 3. The flow rate adjustment unit 6 may be constituted by, for example, a control valve provided in the second path 3.

[0021] The heating unit 7 is capable of heating the heat exchange unit 4. More specifically, the heating unit 7 in this embodiment is mounted on the outer surface of the heat exchanger constituting the heat exchange unit 4, and heats the heat exchanger from the outside. The heating unit 7 may be composed of, for example, an electric heating wire wrapped around the heat exchanger. Alternatively, the heating unit 7 may be positioned inside the heat exchanger to heat the heat exchanger from the inside. Furthermore, the heating unit 7 may be positioned at a distance from the heat exchanger and heated by radiant heat or the like.

[0022] The cooling system 1 of this embodiment includes both a flow rate adjustment unit 6 and a heating unit 7. However, the cooling system 1 may also be configured to include only the flow rate adjustment unit 6, or only the heating unit 7. In other words, the cooling system 1 may be configured to include either or both of the flow rate adjustment unit 6 and the heating unit 7.

[0023] The control unit 8 controls the flow rate adjustment unit 6 and the heating unit 7 according to the temperature measurement value from the temperature measurement unit 5. In this embodiment, the control unit 8 is one or more processors. The control unit 8 is implemented by a dedicated processor specialized in the process of controlling the flow rate adjustment unit 6 and the heating unit 7 according to the temperature measurement value from the temperature measurement unit 5, but it may also be implemented by a general-purpose processor such as a CPU (Central Processing Unit). The control unit 8 may include one or more dedicated circuits, and in the control unit 8, one or more processors may be replaced by one or more dedicated circuits. The dedicated circuits are, for example, FPGAs (Field-Programmable Gate Arrays) or ASICs (Application Specific Integrated Circuits). Note that the cooling system 1 may have a separate control unit for controlling the flow rate adjustment unit 6 and a separate control unit for controlling the heating unit 7.

[0024] By using the cooling system 1 configured as described above, heat exchange can be performed between the fluid to be cooled and the cold source fluid, thereby cooling the fluid to be cooled. The method of using the cooling system 1 is not particularly limited, but for example, it may be used to supply the fluid to be cooled in the heat exchange section 4 to a superconducting device and cool the superconducting device. Alternatively, the cooling system 1 may be used to cool and liquefy a gas such as methane gas as the fluid to be cooled.

[0025] As described above, the temperature measuring unit 5 may be configured to measure the temperature of the cold source fluid during the heat exchange with the fluid to be cooled in the heat exchange unit 4, and after the heat exchange with the fluid to be cooled in the heat exchange unit 4, or both. By using the temperature measuring unit 5 to detect the temperature fluctuation of the cold source fluid before and after the solidification of the fluid to be cooled occurs, it is possible to detect when solidification of the fluid to be cooled has occurred. This will be explained in detail with reference to Figure 2.

[0026] Figure 2 is a graph showing an example of the temperature changes of each fluid when heat exchange is performed between the fluid to be cooled and the cold source fluid using the cooling system 1. In the graph in Figure 2, the vertical axis represents temperature T, and the horizontal axis represents time t. In the graph in Figure 2, the solid line represents the change in temperature of the cold source fluid over time TA, and the thick dashed line represents the change in temperature of the fluid to be cooled over time TB. Furthermore, the dotted line on the graph in Figure 2 indicates the time ta at which solidification of the fluid to be cooled occurred. Note that the temperatures of the cold source fluid and the fluid to be cooled in the graph in Figure 2 are measured values ​​of each fluid after heat exchange has been performed in the heat exchange section 4.

[0027] Conventional cooling systems typically manage operation by measuring the temperature of the fluid being cooled. However, as shown in Figure 2, the temperature of the fluid being cooled does not fluctuate significantly before and after the time ta at which solidification occurs. Therefore, in conventional cooling systems that measure the temperature of the fluid being cooled, it is difficult to detect when solidification has occurred. On the other hand, as shown in Figure 2, the temperature of the cold source fluid decreases significantly after the time ta at which solidification occurs. This is because when solidification occurs in the fluid being cooled, it becomes difficult for the fluid to flow through the first path 2, reducing the efficiency of heat exchange between the fluid being cooled and the cold source fluid. Therefore, in this embodiment, by measuring the temperature of the cold source fluid, it is possible to easily detect when solidification has occurred in the fluid being cooled by detecting the temperature fluctuation of the cold source fluid before and after the solidification occurs.

[0028] In this embodiment, the temperature measuring unit 5 measures the temperature of the cold source fluid after heat exchange has taken place with the fluid to be cooled in the heat exchange unit 4. The fluid to be cooled is in its most cooled state and is most prone to solidification after heat exchange has taken place with the cold source fluid in the heat exchange unit 4. Therefore, as in this embodiment, measuring the temperature of the cold source fluid after heat exchange has taken place with the fluid to be cooled in the heat exchange unit 4 makes it easier to detect when solidification of the fluid to be cooled has occurred. Furthermore, as described above, the temperature measuring unit 5 may be configured to measure the temperature of the cold source fluid while heat exchange is taking place with the fluid to be cooled in the heat exchange unit 4. In this case, it is possible to detect when solidification of the fluid to be cooled occurs earlier compared to the case where only the temperature of the cold source fluid after heat exchange has taken place with the fluid to be cooled in the heat exchange unit 4 is measured. Moreover, as described above, the temperature measuring unit 5 may be configured to measure the temperature of the cold source fluid both during heat exchange with the fluid to be cooled in the heat exchange unit 4 and after heat exchange has taken place with the fluid to be cooled in the heat exchange unit 4. In this case, it is easier to detect when solidification of the fluid to be cooled has occurred, and it is possible to detect when solidification of the fluid to be cooled occurs earlier.

[0029] If solidification occurs in the fluid being cooled, the cooling system 1 can continue operating if the solidification is localized. However, if the solidification progresses, the first path 2 may become blocked, potentially preventing the cooling system 1 from continuing to operate. In contrast, the cooling system 1 of this embodiment includes a flow rate adjustment unit 6. Therefore, when solidification of the fluid being cooled is detected from the temperature measurement unit 5, the flow rate adjustment unit 6 reduces the amount of cold source fluid supplied to the heat exchange unit 4, thereby suppressing the progression of solidification of the fluid being cooled. In this embodiment, the control unit 8 can control the flow rate adjustment unit 6 based on the temperature measurement unit 5. Specifically, the control unit 8 can control the flow rate adjustment unit 6 to reduce the amount of cold source fluid supplied to the heat exchange unit 4 when the temperature measurement unit 5 is below a predetermined temperature. Furthermore, the cooling system 1 of this embodiment includes a heating unit 7. Therefore, when solidification of the fluid being cooled is detected from the temperature measurement unit 5, the heating unit 7 heats the heat exchange unit 4, thereby suppressing the progression of solidification of the fluid being cooled. In this embodiment, the control unit 8 can control the heating unit 7 based on the measurement value of the temperature measuring unit 5. Specifically, the control unit 8 can control the heating unit 7 to heat the heat exchange unit 4 when the measurement value of the temperature measuring unit 5 is below a predetermined temperature. In other words, by providing one or both of the flow rate adjustment unit 6 and the heating unit 7, the cooling system 1 can suppress the progression of solidification of the cooled fluid when solidification of the cooled fluid is detected from the measurement value of the temperature measuring unit 5, thereby preventing the first path from being blocked. The predetermined temperature may be, for example, the same temperature as the solidification point of the cooled fluid or a temperature near the solidification point of the cooled fluid.

[0030] As described above, according to the cooling system 1 of this embodiment, even when the fluid to be cooled is cooled by heat exchange with a cold source fluid at a temperature lower than the freezing point of the fluid to be cooled, it is possible to suppress the blockage of the path through which the fluid to be cooled flows (the first path 2 in this embodiment).

[0031] <Second Embodiment> Next, with reference to Figure 3, a cooling system 10 as a second embodiment will be described. Figure 3 is a diagram showing the configuration of the cooling system 10. Compared to the cooling system 1 as the first embodiment (see Figure 1), the cooling system 10 shown in Figure 3 differs mainly in the configuration of the heat exchange unit, temperature measurement unit, and heating unit, while other configurations are common. Therefore, only the above-mentioned differences will be explained here, and the explanation of the common configurations will be omitted.

[0032] As shown in Figure 3, the heat exchange unit 40 of this embodiment includes a plurality of heat exchangers 41 arranged in series along the first path 2 and the second path 3. In this embodiment, heat exchange takes place in each of the plurality of heat exchangers 41 between the fluid to be cooled flowing through the first path 2 and the cold source fluid flowing through the second path 3. Each of the plurality of heat exchangers 41 may be a heat exchanger as exemplified in the description of the first embodiment.

[0033] As shown in Figure 3, the heat exchange section 40 of this embodiment includes two heat exchangers 41. For the sake of explanation, the upstream heat exchanger 41 of the two heat exchangers 41 of this embodiment will be referred to as the "first heat exchanger 41a," and the downstream heat exchanger 41 as the "second heat exchanger 41b."

[0034] The temperature measuring unit 50 of this embodiment measures the temperature of the cold source fluid after heat exchange with the fluid to be cooled has taken place in the first heat exchanger 41a, and the temperature of the cold source fluid after heat exchange with the fluid to be cooled has taken place in both the first heat exchanger 41a and the second heat exchanger 41b. In other words, the temperature measuring unit 50 of this embodiment measures the outlet temperature of the cold source fluid in each of the multiple heat exchangers 41. Thus, the temperature measuring unit 50 may be configured to measure the temperature of the cold source fluid at two or more locations in the second path 3. However, the temperature measuring unit 50 may be configured to measure only the temperature of the cold source fluid after heat exchange with the fluid to be cooled has taken place in the first heat exchanger 41a, or it may be configured to measure only the temperature of the cold source fluid after heat exchange with the fluid to be cooled has taken place in both the first heat exchanger 41a and the second heat exchanger 41b. In other words, the temperature measuring unit 50 may be configured to measure the temperature of the cold source fluid after heat exchange with the fluid to be cooled has taken place in at least one of the multiple heat exchangers 41. Alternatively, the temperature measuring unit 50 may be configured to measure the temperature of the cold source fluid while heat exchange with the fluid to be cooled is taking place in at least one heat exchanger 41. In this case, the temperature measuring unit 50 may be incorporated inside at least one heat exchanger 41. Furthermore, the temperature measuring unit 50 may be configured to measure the outlet temperature of the cold source fluid in at least one heat exchanger 41, as well as the temperature of the cold source fluid while heat exchange with the fluid to be cooled is taking place.

[0035] The cooling system 10 of this embodiment includes two temperature measuring units 50 provided in the second path 3. Of the two temperature measuring units 50, one is provided in the second path 3 between the first heat exchanger 41a and the second heat exchanger 41b, and the other temperature measuring unit 50 is provided in the second path 3 downstream of the second heat exchanger 41b. Each temperature measuring unit 50 may be composed of a thermometer or the like as exemplified in the description of the first embodiment.

[0036] The cooling system 10 of this embodiment includes a plurality of heating units 70 attached to each of the plurality of heat exchangers 41. Each heating unit 70 may be composed of an electric heating wire or the like as exemplified in the description of the first embodiment. However, the heating unit 70 may be attached to only one of the plurality of heat exchangers 41, for example. In other words, the heating unit 70 may be configured to heat at least a part of the heat exchanger 40.

[0037] As described above, the heat exchange section 40 of this embodiment includes a plurality of heat exchangers 41. This allows the configuration of the heat exchange section 40 to be flexibly changed to suit various conditions such as installation space and the characteristics of the cold source fluid, by composing each of the plurality of heat exchangers 41 with heat exchangers of different structures and sizes.

[0038] Furthermore, as described above, the temperature measuring unit 50 of this embodiment may be configured to measure the temperature of the cold source fluid after heat exchange with the cooled fluid has occurred in at least one of the multiple heat exchangers 41. This allows the temperature measuring unit 50 to detect fluctuations in the temperature of the cold source fluid before and after solidification of the cooled fluid, and to detect when solidification of the cooled fluid has occurred. Also, as described above, the cooling system 10 may include multiple temperature measuring units 50 that measure the temperature of the cold source fluid at two or more locations in the second path 3. In this case, compared to a configuration in which only one temperature measuring unit 50 measures the temperature at one location in the second path 3, the speed and reliability of detecting when solidification of the cooled fluid has occurred can be improved.

[0039] <Cooling method> Finally, a cooling method as one embodiment of the cooling method according to the present invention will be described, using the cooling system 1 of the first embodiment or the cooling system 10 of the second embodiment described above. For the sake of explanation, the following description will focus on the case using cooling system 1, but the same applies when using cooling system 10.

[0040] The cooling method of this embodiment performs one or both of the following actions depending on the temperature of the cold source fluid measured by the temperature measuring unit 5: adjusting the amount of cold source fluid supplied to the heat exchange unit 4 by the flow rate adjustment unit 6, and heating the heat exchange unit 4 by the heating unit 7. Specifically, for example, if solidification of the fluid to be cooled is detected from the measurement value of the temperature measuring unit 5, one or both of the following actions are performed: reducing the amount of cold source fluid supplied to the heat exchange unit 4 by the flow rate adjustment unit 6, and heating the heat exchange unit 4 by the heating unit 7. This suppresses the progression of solidification of the fluid to be cooled and prevents the first path from becoming blocked.

[0041] Specifically, in the cooling method of this embodiment, the control unit 8 performs one or both of the following actions according to the temperature of the cold source fluid measured by the temperature measuring unit 5: adjusting the amount of cold source fluid supplied to the heat exchange unit 4 by the flow rate adjustment unit 6, and heating the heat exchange unit 4 by the heating unit 7. For example, the control unit 8 may control the flow rate adjustment unit 6 to reduce the amount of cold source fluid supplied to the heat exchange unit 4 when the measurement value from the temperature measuring unit 5 is below a predetermined temperature. Alternatively, the control unit 8 may control the heating unit 7 to heat the heat exchange unit 4 when the measurement value from the temperature measuring unit 5 is below a predetermined temperature. The predetermined temperature may be, for example, the same temperature as the freezing point of the fluid to be cooled or a temperature near the freezing point of the fluid to be cooled.

[0042] The cooling system and cooling method according to the present invention are not limited to the specific configurations shown in the embodiments described above, and various modifications, changes, and combinations are possible as long as they do not depart from the scope of the claims. In the embodiments described above, an example was shown in which the control unit controls one or both of the flow rate adjustment unit and the heating unit, but the flow rate adjustment unit and the heating unit may be controlled, for example, manually. [Industrial applicability]

[0043] The present invention relates to a cooling system and a cooling method. [Explanation of symbols]

[0044] 1. 10: Cooling System 2: First route 3: Second route 4, 40: Heat exchange section 5, 50: Temperature measurement part 6:Flow rate adjustment part 7, 70: Heating section 41:Heat exchanger 41a: First heat exchanger 41b: Second heat exchanger TA: Temperature change over time of cold source fluid TB: Temperature change of the cooled fluid over time ta: Time at which solidification of the cooled fluid occurred

Claims

1. The first path through which the fluid to be cooled flows, The second pathway through which the cold source fluid flows, A heat exchange unit that cools the fluid to be cooled by performing heat exchange between the fluid to be cooled flowing through the first path and the cold source fluid flowing through the second path, A temperature measuring unit that measures the temperature of the cold source fluid during the heat exchange with the fluid to be cooled in the heat exchange unit, and after the heat exchange with the fluid to be cooled in the heat exchange unit, or both of these times, A cooling system comprising one or both of the following: a flow rate adjustment unit capable of adjusting the amount of the cold source fluid supplied to the heat exchange unit, and a heating unit capable of heating the heat exchange unit.

2. The heat exchange section comprises a plurality of heat exchangers arranged in series along the first path and the second path, The cooling system according to claim 1, wherein the temperature measuring unit measures the temperature of the cold source fluid after heat exchange has been performed with the cooled fluid in at least one of the plurality of heat exchangers.

3. A cooling method using the cooling system described in claim 1 or 2, A cooling method comprising, in accordance with the temperature of the cold source fluid measured by the temperature measuring unit, either or both of the following are performed: adjusting the amount of cold source fluid supplied to the heat exchange unit by the flow rate adjustment unit, and heating the heat exchange unit by the heating unit.

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