WO2007040033A1

WO2007040033A1 - Cooling system, operation method for the cooling system, and plasma processing system using the cooling system

Info

Publication number: WO2007040033A1
Application number: PCT/JP2006/318385
Authority: WO
Inventors: Katsushi Kishimoto
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2005-09-30
Filing date: 2006-09-15
Publication date: 2007-04-12
Also published as: US20090113912A1; TWI323330B; JPWO2007040033A1; TW200726949A

Abstract

A cooling system in which a compressor (1), a heat source (2), a heat exchanger (3), and a buffer tank (4) are connected in that order by piping (5) to form a closed circuit. In the closed circuit, nitrogen as the refrigerant is circulated without being in contact with the outside air. The refrigerant is sufficient if only it is gas (refrigerant) other than air, absorbs heat from the heat source (2) without being liquefied when circulated in the closed circuit, and discharges the heat to the outside at the heat exchanger (3).

Description

Specification

Cooling system, operating method thereof and plasma processing system using the cooling system

The present invention relates to a cooling system that cools a heat source with a refrigerant, an operating method thereof, and a plasma processing system using the cooling system

It is about.

Background art

[0002] Conventionally, heat pumps have been used. A heat pump is a system that performs cooling or heating. In heat pumps, heat of vaporization is used. The heat of vaporization is heat that the refrigerant absorbs from the surroundings when the refrigerant changes from liquid to gas. Heat pump also uses heat of condensation. Condensation heat is the heat that the refrigerant releases to the surroundings when it changes from gas to liquid. In heat pumps, compressors and heat exchangers are used to utilize the heat of vaporization and condensation.

[0003] More specifically, the above-described heat pump is used in an internal combustion engine, a refrigerator, or the like. These usually have a built-in cooling system that also has a closed circuit force. In the cooling system, liquid refrigerant such as chlorofluorocarbon gas is vaporized by adiabatic expansion. As a result, an endothermic effect occurs. The compressor compresses the vaporized refrigerant in an adiabatic state. Thereby, the vaporized refrigerant is condensed and returned to the liquid refrigerant. Such a heat exchange cycle is repeated. According to the heat exchange cycle as described above, a large amount of heat can be exchanged efficiently.

[0004] On the other hand, the surface areas of furnaces, tanks, and chimneys in large plants are very large. In the cooling of a large plant having this large surface, the heat of vaporization of the refrigerant flowing in the refrigerant pipe provided so as to meander along the surface is used. In this case, a force that causes rapid cooling by the heat of vaporization at a position near the inlet of the refrigerant pipe. Since the liquid refrigerant has already vaporized at a position near the outlet of the refrigerant pipe, the heat of vaporization Cooling is not performed. For this reason, when a large plant or the like is cooled by using a heat exchange cycle that involves a phase change between a liquid and a gas as described above, extreme variations in the surface temperature distribution will occur. Therefore, as a refrigerant for a heat pump for cooling a specific large plant facility, a gas such as nitrogen or an inert gas argon is used because of its low specific heat.

Patent Document 1: JP-A-1 193561

Patent Document 2: Japanese Patent Laid-Open No. 2003-329355

Disclosure of the invention

Problems to be solved by the invention

[0005] The conventional heat pump using the heat of vaporization and the heat of condensation in which the gas as described above is used as a refrigerant has the following problems.

First, consider a case where gas is used as a coolant for cooling a heat source in a closed circuit of a heat pump. In this case, when cooling is performed using the heat of vaporization and heat of condensation, all the gas may change into a liquid between the inlet and outlet of the cooling pipe. In this case, the heat absorption capacity of the refrigerant differs greatly depending on the position of the cooling pipe. Therefore, large unevenness occurs in the temperature distribution in the cooling pipe. Therefore, the heat source cannot be cooled uniformly! /.

[0007] Next, consider a case in which the heat source is cooled by a method in which gas flows through an open circuit rather than circulating in a closed circuit and then sequentially discharged. In general, a gas has a much lower specific heat than a liquid such as water. Therefore, in the case described above, depending on the form of the open circuit, it is necessary to discharge a large amount of gas. Therefore, the consumption of gas becomes extremely large. As a result, the running cost of the heat pump is greatly increased. This gas can be reused for other purposes. The equipment for reusing the power gas is large, so there is a large cost penalty.

Next, consider a case where the heat source is cooled using normal cooling water as a refrigerant. In this case, since the specific heat of water is large, the variation in the surface temperature distribution of the large heat source becomes large. Therefore, such a cooling system using water as the refrigerant is not suitable as a cooling system for uniformly cooling the heat source. If the heat source is installed in a vacuum atmosphere Easily reacts with water in the surrounding atmosphere!ヽ In the presence of dredged material, if water leaks from the cooling pipe, the water vapor explosion that occurs because the vacuum chamber is pressurized above atmospheric pressure, and the reaction of the leaked water with the surrounding atmosphere causes There is a risk of damage.

[0009] Further, let us consider a case where temperature control is performed using pressurized water as in a mold incubator. In this case, it is impossible in principle to cool a heat source having a temperature of 160 ° C. or higher. In addition, as above, there is a risk of steam explosion and damage to the periphery of the cooling system.

[0010] The present invention has been made in view of the above-described problems, and an object of the present invention is to use a cooling system capable of uniformly cooling a large heat source, an operation method thereof, and the cooling system.

V, is to provide a plasma processing system.

Means for solving the problem

[0011] The cooling system of the present invention includes a compressor that compresses and sends gas refrigerant other than air to a level that does not liquefy, and a heat source that is cooled by the gas refrigerant when the compressed gas refrigerant passes through the compressor. It has. The system also includes a heat exchanger in which the gas refrigerant after absorbing heat from the heat source releases heat to the outside, and the gas refrigerant after releasing heat to the heat exchanger! A compressor tank, a heat source, a heat exchanger, and a buffer tank are connected in this order to form a closed circuit, and piping for circulating the gas refrigerant is provided.

[0012] According to the above configuration, since the heat source is cooled using the gas refrigerant having a small specific heat, when the heat source having a large surface is cooled, the cooling using the liquid refrigerant having a large specific heat is used to cool the heat source. Compared to a cooling system that cools the heat source by a system or refrigerant phase change, the degree of uneven temperature distribution on the surface of the heat source can be reduced. In addition, when gas is used as the refrigerant, there is a risk that problems caused by the reaction between the gas and other substances may occur. However, according to the above-described configuration, the gas refrigerant circulates in the closed circuit, so that the above-described problems do not occur.

[0013] Further, if the cooling system further includes another kaffa tank that temporarily stores the gaseous refrigerant between the compressor and the heat source, the flow rate of the gas supplied to the heat source is stabilized.

[0014] Further, the capacity power of the buffer tank described above is necessary for the gaseous refrigerant to circulate once in the closed circuit. If the amount of gas refrigerant discharged by the compressor is equal to or greater than the amount of gas refrigerant discharged, the risk of losing the gas refrigerant discharged by the compressor is reduced.

[0015] Further, the cooling system includes a replenishment pipe connected to the buffer tank so that the gas refrigerant can be replenished with an external force, and a discharge pipe connected to the buffer tank so that the gas refrigerant can be discharged to the outside. It is desirable to further include.

[0016] According to the above configuration, when the amount of the gaseous refrigerant in the notch tank is too small, it is possible to replenish the gaseous refrigerant from the outside to the buffer tank via the supplementary piping. When the amount of the gaseous refrigerant in the inside is too large, the gaseous refrigerant can be discharged from the notifier tank to the outside through the discharge pipe.

[0017] Further, if the compressor has the capability of discharging a larger amount of gaseous refrigerant than the circulation amount of gaseous refrigerant necessary for cooling the heat source to the target temperature, the gaseous refrigerant to the heat source is discharged. If there is a shortage of supply, there will be no situation.

[0018] Further, it is desirable that the gaseous refrigerant contains nitrogen, oxygen, carbon dioxide, or an inert gas. Since these gaseous refrigerants are less likely to react with other substances, they are less likely to adversely affect the surrounding environment if the gaseous refrigerant leaks outside the closed circuit.

[0019] Moreover, the pipe, in the heat source acts as a cooling pipe, the surface area of the cooling tubes is equal heat lm ³ Ah or 20 cm ² or more and 750 cm ² or less, it is possible to perform sufficient heat exchange.

[0020] Further, if the pressure loss of the gaseous refrigerant in the heat exchanger is 1Z10 or less of the pressure loss of the gaseous refrigerant in the entire closed circuit, the heat exchange ^^ obstructs the flow of the gaseous refrigerant necessary for cooling the heat source. What to do.

[0021] In addition to the cooling system power closed circuit of the present invention, the amount of gaseous refrigerant discharged by the compressor after the compressor is started and before the gaseous refrigerant circulates once in the closed circuit is reduced to the compressor. If the refrigerant supply path that can supply the refrigerant is further provided, the operation immediately after the compressor is started is stabilized.

[0022] In addition, the cooling system of the present invention provides an exhaust valve that automatically exhausts the gas refrigerant in the buffer tank when the pressure of the gas refrigerant in the notch tank is a pressure that is approximately the upper limit of the suction pressure of the compressor. And the pressure of the gas refrigerant in the buffer tank It is desirable to further include an intake valve that automatically sucks the gaseous refrigerant into the buffer tank when the pressure is almost the lower limit of the penetration pressure. According to this, it is possible to automatically ensure the safety of the notch tank and the proper operating state of the compressor.

[0023] The plasma processing system of the present invention is a compressor that compresses and sends a gaseous refrigerant other than air so as not to be liquefied, and an apparatus that generates heat when performing a predetermined process using a plasma processing gas. The compressor processing device includes a plasma processing apparatus that is cooled by the gaseous refrigerant when the gaseous refrigerant that has been sent out passes. In addition, the system includes a heat exchanger in which the gas refrigerant after absorbing heat from the plasma processing apparatus releases heat to the outside, and the gas refrigerant after releasing heat to the outside in the heat exchanger. And a buffer tank for temporarily storing water. In addition, the system forms a closed circuit that connects the compressor, the heat source, the heat exchanger, and the buffer tank in this order, and includes a pipe for circulating the gaseous refrigerant in the closed circuit. The gas refrigerant also has one or more gas forces that do not react with the plasma processing gas.

[0024] The operation method of the cooling system of the present invention is the above-described operation method of the cooling system, and when the compressor is started, the gas refrigerant pressure in the buffer tank is reduced to the buffer tank. After the step of sucking the gas refrigerant and the time longer than the time necessary for circulating the gas refrigerant in the closed circuit has elapsed, the pressure of the gas refrigerant in the buffer tank is set to a value that does not damage the compressor. And maintaining steps. According to this, since the state where the gaseous refrigerant is not supplied to the compressor does not occur, the compressor is prevented from being damaged.

The invention's effect

[0025] According to the present invention, since a gas having a small specific heat is used as the refrigerant, variations in the temperature surface of the heat source hardly occur. In addition, since the gas refrigerant circulates in the closed circuit, an increase in running cost can be suppressed. In addition, since the type of gas can be arbitrarily selected, the heat source can be safely cooled if a gas with low risk is used according to the atmosphere around the heat source. Furthermore, since the cooling system of the present invention does not use the phase change between gas and liquid, the cooling capacity can be adjusted relatively easily. [0026] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration of a cooling system according to an embodiment.

FIG. 2 is a diagram showing a compressor used in the cooling system of the embodiment.

FIG. 3 is a diagram showing a configuration of a cooling system of another example of the embodiment.

FIG. 4 is a diagram showing a heat source used in the cooling system of the embodiment.

FIG. 5 is a diagram showing a heat exchanger used in the cooling system of the embodiment.

FIG. 6 is a diagram showing a buffer tank used in the cooling system of the embodiment.

Explanation of symbols

[0028] 1 compressor, 2 heat source (large heater), 3 heat exchanger ^^, 4 buffer tank.

BEST MODE FOR CARRYING OUT THE INVENTION

[0029] A cooling system according to an embodiment of the present invention will be described with reference to the drawings.

The cooling system of the embodiment is used for cooling a heat source that needs to be cooled while maintaining a uniform temperature distribution on the surface, for example, a large heater. In the embodiment, the heat source to be cooled is installed in an atmosphere that easily reacts with oxygen. Therefore, nitrogen or argon can be considered as the refrigerant of this cooling system. However, the refrigerant is appropriately selected according to the atmosphere around the heat source, and is not limited to the aforementioned refrigerant as long as it is a gas. Moreover, each device used in the cooling system of the present embodiment is an example, and each device used in the cooling system of the present invention is not limited to the one described below.

[0030] The overall configuration of the cooling system 100 of the embodiment will be described with reference to FIG.

As shown in FIG. 1, the cooling system 100 of the present embodiment includes a compressor 1 stored in a notch tank 4 for sucking in and sucking in the refrigerant, and compressing and feeding the refrigerant. Nitrogen is used as the refrigerant sent out by the compressor 1 in consideration of price and thermal conductivity. As nitrogen passes through heat source 2, it takes heat away from heat source 2 and cools heat source 2. Nitrogen deprived of heat from heat source 2 reaches heat exchanger 3. In the heat exchanger 3, the nitrogen releases heat to the outside. Thereby, the temperature of nitrogen falls. Then nitrogen is It reaches the noffer tank 4 and is temporarily stored.

[0031] Further, in the present embodiment, the compressor 1, the heat source 2, the heat exchanger 3, and the buffer tank 4 are connected in this order by the pipe 5 through which nitrogen flows, so that the nitrogen is not touched by the outside air. A closed circuit that circulates is configured. Note that the refrigerant circulating in the closed circuit is a gas other than air that absorbs heat from a heat source that does not liquefy when circulating in the closed circuit, and releases the heat to the outside. Any gas may be used.

[0032] According to the cooling system of the present embodiment as described above, since the heat source 2 having a large surface area is cooled using nitrogen having a small specific heat, a liquid having a large specific heat is used, or a phase change of the cooling medium. Compared with the case where the heat source is cooled by this, the degree of uneven temperature distribution on the surface of the heat source 2 can be reduced. In addition, if nitrogen is used in an atmosphere that reacts with nitrogen, there is a risk that problems may occur due to the reaction between nitrogen and other substances. In this embodiment, nitrogen is contained in a closed circuit. The above-mentioned problems are not likely to occur.

[0033] For example, in the compressor 1, as shown in FIG. 2, the rotation of the rotating body lc that is rotated by a motor (not shown) or the like is transmitted to the piston la by a crank or the like. As a result, the piston la reciprocates in the cylinder le. Further, as indicated by an arrow in FIG. 1, nitrogen flowing through the pipe 5 is sucked into the cylinder le from the suction port If. In the cylinder le, nitrogen is compressed by the piston la. As a result, the plate panel valve Id is opened by the increased pressure of nitrogen. Thereby, as indicated by an arrow in FIG. 2, nitrogen in the cylinder le is discharged from the discharge port lg to the pipe 5. The nitrogen exhaled by compressor 1 is a gas. That is, the compressor 1 compresses and discharges gaseous nitrogen to such an extent that it does not liquefy.

[0034] Further, the compressor 1 has an ability to discharge a larger amount of gas than the amount of gas circulation required for cooling the heat source 2 to a target temperature. Therefore, if the supply of nitrogen to heat source 2 is insufficient, a situation will not occur.

[0035] Further, the cooling system of the present embodiment separates the amount of nitrogen discharged by the compressor 1 while the nitrogen circulates once in the closed circuit after the compressor 1 is started, separately from the closed circuit. Another nitrogen supply path for supplying to the presser 1 is provided. Specifically, other nitrogen As shown in FIG. 1, the element supply path is a nitrogen replenishment pipe 8a connected to a notch tank 4. Therefore, immediately after the compressor 1 is started, the nitrogen replenishment control valve 80 a is opened, nitrogen is supplied from the nitrogen tank 200 into the buffer tank 4, and nitrogen is sequentially fed into the compressor 1. Therefore, the operation immediately after the compressor 1 starts is stable. In the closed circuit shown in Fig. 1, the time for nitrogen to circulate once at a speed of lm ³ Zmin is 6 seconds.

In the present embodiment, it is assumed that the heat quantity of about 50 KcalZcm ² Zh needs to be uniformly removed from the large heater as the heat source 2. Therefore, if the temperature difference between the large heater and the refrigerant nitrogen (Δ is 150 ° C), it is necessary to constantly circulate the nitrogen in the closed circuit at a speed of lm ³ Zmin. Is selected so that it can circulate nitrogen at a discharge rate of lm ³ / min or more, but the discharge rate of compressor 1 must be determined in consideration of the pressure loss of the entire pipe 5. The discharge amount of nitrogen from the compressor 1 is preferably at least 1.2 times the required circulation amount of nitrogen, but the value is more preferably 1.5 times or more. Considering the pressure loss caused by the 5 curved parts and the valves provided in the pipe 5, sufficient nitrogen circulation flow rate can be secured.

[0037] In order to mitigate fluctuations in the operating rate of the compressor 1 in response to load fluctuations, as shown in Fig. 3, gas temporarily accumulates between the compressor 1 and the heat source 2 and can withstand high pressure. Other koffa tanks 6 may be provided. According to this, the flow rate of the gas supplied to the heat source 2 is stabilized. However, the koffa tank 6 is provided as necessary, and is not an essential component of the present invention.

[0038] Further, since the heat source 2 has a large surface area, as shown in FIG. 4, a pipe 5 through which nitrogen circulates is provided to meander. Nitrogen is fed from the compressor 1 to the meandering pipe 5 in the heat source 2 through the inlet 2a. The nitrogen that has passed through the heat source 2 is sent out to the pipe 5 through the outlet 2b. According to the cooling system 100 of the present embodiment, since nitrogen having a small specific heat is used as the refrigerant, the heat exchange capacity of nitrogen near the inlet 2a of the heat source 2 and the heat exchange capacity of nitrogen near the outlet 2b of the heat source 2 There is almost no difference. Therefore, the temperature distribution on the surface of the heat source 2 is not uneven. Further, as shown in FIG. 5, the heat exchanger 3 is provided so that the pipe 5 meanders. The nitrogen that has passed through the heat source 2 is sent to the meandering pipe 5 through the heat exchanger 3 through the inlet 3a, and releases heat to the outside while flowing through the meandering pipe 5. In the heat exchanger 3, the heat of nitrogen is transmitted to the cooling water that flows from the inlet pipe 7a to the outlet pipe 7b. Further, nitrogen flowing in the heat exchanger 3 is discharged to the pipe 5 through the outlet 3b.

[0040] Further, as shown in FIG. 1, the cooling water is stored in the cooling water tank 300 and is circulated between the cooling water tank 300 and the heat exchanger ^^ 3 by the cooling water pump 310. Yes. Therefore, the temperature of the nitrogen that has passed through the heat exchanger 3 has decreased, and the temperature is such that heat can be taken from the heat source 2 again when passing through the heat source 2. The cooling water pump 310 is controlled by the control device 30. Moreover, the cooling water tank 300 is provided with a cooling fan, and heat exchange is performed between the atmosphere and the cooling water.

[0041] Further, the pressure loss of nitrogen in the heat exchanger 3 is 1Z10 or less of the pressure loss of nitrogen in the entire closed circuit. Therefore, the heat exchanger 3 does not impede the nitrogen flow necessary for cooling the heat source 2.

[0042] Further, the surface area of the piping 5 as a cooling pipe in the heat source 2 is either One 750 cm ² or less heat lm ³ per 20 cm ² or more. Therefore, the heat source 2 has a sufficient heat exchange capability.

[0043] Generally, the heat exchanger 3 needs to perform heat exchange in an amount excluding the amount of heat released from nitrogen in the pipe 5. However, in the present embodiment, even when the heat radiation amount of the pipe 5 can be ignored, the heat exchange 3 needs to be able to perform heat exchange of about 50 KcalZcm ² Zh or more. Further, since a large amount of nitrogen gas needs to flow through the pipe 5 in the heat exchanger 3, it is also necessary to reduce the pressure loss of the pipe 5. Furthermore, it is necessary to exchange heat smoothly. Therefore, it is desirable that the pipe 5 be made of a material having a high thermal conductivity such as copper or aluminum. As a result, the size of the heat exchange ^^ 3 can be reduced.

Further, as shown in FIG. 6, the pipe 5 is also connected to the koffa tank 4 and introduced into the buffer tank 4 through the nitrogen power inlet 4a which has finished the heat exchange in the heat exchange 3, and then the buffer tank 4 is stored. Then, every time the space in the cylinder le becomes negative due to the reciprocating motion of the piston la of the compressor 1, nitrogen is sucked into the compressor 1 from the kaffa tank 4. It is. Nitrogen in the notch tank 4 is sent out to the pipe 5 through the outlet 4b.

[0045] Further, the capacity force nitrogen of the buffer tank 4 described above is equal to or more than the amount of nitrogen discharged by the compressor 1 within the time required for one circulation of the closed circuit. More specifically, the capacity of the noffer tank 4 is 100L or more. The capacity of the buffer tank 4 greatly affects the stability of the closed circuit, so it is desirable that the safety factor is high. Specifically, the safety factor of the noffer tank 4 is preferably 2 or more. A safety factor of 2 means that a capacity of 200L is secured for the required capacity of 10 OL. According to the above-described configuration, the nitrogen discharged from the compressor 1 does not disappear in the buffer tank 4. For this reason, there is no situation where the compressor 1 continues to drive even though there is no nitrogen supplied to the compressor 1. As a result, the risk of damage to the compressor 1 is reduced.

Further, as shown in FIG. 6, the notfer tank 4 is connected to a nitrogen replenishing pipe 8a for replenishing nitrogen from the outside and a nitrogen exhausting pipe 8b for discharging gas to the outside. Further, the nitrogen replenishment pipe 8a and the nitrogen discharge pipe 8b are connected to a nitrogen tank 200 as shown in FIG. A nitrogen replenishment pump 210 is provided in the nitrogen replenishment pipe 8a. The nitrogen exhaust pipe 8b is provided with a nitrogen exhaust pump 220.

[0047] Further, the nitrogen supply pipe 8a and the nitrogen discharge pipe 8b are provided with a nitrogen supply control valve 80a and a nitrogen discharge control valve 80b, respectively. The nitrogen replenishment control valve 80a, the nitrogen discharge control valve 80b, the nitrogen replenishment pump 210, and the nitrogen discharge pump 220 are each controlled by the control device 30. The control device 30 receives a signal capable of specifying the measurement value of the pressure sensor 20 provided in the notch tank 4, and based on the signal, the nitrogen replenishment control valve 80a, the nitrogen discharge control valve 80b, and the nitrogen replenishment control valve The pump 210 and the nitrogen exhaust pump 220 are controlled. The control device 30 also controls the compressor 1.

[0048] During the operation of the cooling system of the present embodiment, immediately after starting the compressor 1, the control device 30 is the amount that the gas pressure in the buffer tank 4 has decreased due to the start of the compressor 1. In order to supply nitrogen into the notch tank 4, the nitrogen replenishment control valve 80a is opened and the nitrogen replenishment pump 210 is driven. Also, the control device 30 After a time longer than the time necessary for one circulation of nitrogen in the closed circuit has elapsed, the gas pressure in the kaffa tank 4 is such a value that does not damage the compressor 1, for example, positive pressure 0.5 atm. As described below, the opening and closing of the nitrogen replenishment control valve 80a and the nitrogen discharge control valve 80b and the driving states of the nitrogen replenishment pump 210 and the nitrogen discharge pump 220 are controlled.

In other words, when the amount of nitrogen in the notch tank 4 is too small, the control device 30 opens the nitrogen replenishment control valve 80a and drives the nitrogen replenishing pump 210 to supply the nitrogen replenishing piping. Nitrogen is replenished from the nitrogen tank 200 to the buffer tank 4 through 8a. If the amount of nitrogen in the notifier tank 4 is too large, the control device 30 opens the nitrogen discharge control valve 80b and drives the nitrogen discharge pump 220 to pass through the nitrogen discharge pipe 8b. Then, nitrogen is exhausted from the noffer tank 4 to the nitrogen tank 200. Therefore, the compressor 1 is prevented from being damaged because no state is generated unless nitrogen is supplied to the compressor 1.

[0050] Further, when the control device 30 detects from the signal received from the pressure sensor 20 that the pressure of the nitrogen in the notch tank 4 is approximately the upper limit of the suction pressure of the compressor 1, The nitrogen replenishment control valve 80a is closed and the nitrogen discharge control valve 80b is opened, and the nitrogen discharge pump 220 is driven to automatically discharge the nitrogen in the buffer tank 4. In addition, when the control device 30 detects that the pressure of nitrogen in the stopper tank 4 is a pressure almost equal to the suction pressure of the compressor 1 based on a signal received from the pressure sensor 20, the nitrogen discharge control valve 80b Is closed and the nitrogen replenishment control knob 80a is opened, and the nitrogen replenishment pump 210 can be driven to automatically suck nitrogen into the buffer tank 4. The upper limit value and the lower limit value described above are values determined for each type of the compressor 1, and if an amount of nitrogen within the range defined by these values is supplied into the buffer tank 4, , Compressor 1 and buffer tank 4 will not be damaged. Therefore, according to the above configuration, the safety of the koffa tank 4 and the proper operating state of the compressor 1 can be automatically ensured.

[0051] In the present embodiment, oxygen, carbon dioxide, or an inert gas (for example, argon) may be used in place of nitrogen as the refrigerant. Yes. Since these gases are less likely to react with other substances, they are less likely to adversely affect the surrounding environment if the gas leaks outside the closed circuit.

[0052] In particular, when a heat source installed in a high-temperature vacuum atmosphere is cooled using a liquid refrigerant, the liquid may boil and explode, for example, a steam explosion may occur. Therefore, in this case, liquid refrigerant cannot be used in the cooling system. Also, for example, there is an apparatus that forms a vacuum atmosphere that is highly reactive or highly toxic and contains a slight amount of gas, such as a plasma CVD (Chemical Vapor Deposition) apparatus. Such a plasma processing apparatus generates heat in a process of performing a desired process using a predetermined gas. When a cooling system in which such a plasma processing apparatus is incorporated as the heat source 2 is used, the cooling efficiency is taken into consideration, and the reaction with the gas that has been used in the plasma processing apparatus. It is desirable to use a gas refrigerant. According to this, even if the gas used for the plasma processing in the plasma processing apparatus leaks out of the plasma processing apparatus power and the gaseous refrigerant leaks out from the piping 5 of the cooling system, the gases react with each other. (For example, a chemical reaction) will not cause problems. Therefore, the safety of the plasma processing system using the above-described cooling system is improved. The gas refrigerant may be one kind of gas force or may be composed of multiple kinds of gases! /.

[0053] According to the cooling system 100 of the above-described embodiment, when the large heat source 2 is cooled, the high temperature heat source 2 can be cooled without adopting a large-scale structure. As a result, safety can be ensured and the heat source can be cooled uniformly without damaging the surrounding area.

Next, an operation method of the cooling system of the embodiment will be described.

First, after starting the compressor 1, the control device 30 opens the valve 10 provided between the buffer tank 4 and the compressor 1 shown in FIG. At this time, nitrogen is supplied from the nitrogen replenishment pipe 8a to the buffer tank 4 in order to prevent the compressor 1 from operating in a negative pressure state. In particular, during the period until nitrogen circulates and the cooling system 100 reaches a steady state (within 6 seconds), the compressor 1 is likely to operate in a negative pressure state, so it is necessary to supply nitrogen to the notch tank 4. is there. Thereafter, when nitrogen circulates through the closed circuit pipe 5, the pressure in the kaffa tank 4 is stabilized, and the compressor 1 operates in a positive pressure state in which no load is generated. Further, when the space in the cylinder le of the compressor 1 becomes excessively positive pressure, the nitrogen discharge control valve 80b is opened, and the nitrogen in the notch tank 4 is discharged. As a result, the compressor 1 can be operated stably.

[0056] According to the cooling system of the present embodiment, nitrogen as a refrigerant is circulated and used, and there is no need to supply a new refrigerant. Therefore, the running cost is only the cost of the power consumption of the compressor 1, so that the cost can be greatly reduced compared to the cooling system that sequentially discharges nitrogen.

[0057] Force that has described and illustrated this invention in detail. This is for illustrative purposes only, and not as a limitation, and it is clear that the scope of the invention is limited only by the appended claims. Will be understood.

Claims

The scope of the claims

[1] A compressor (1) that compresses and sends gas refrigerant other than air to a level that does not liquefy, and a heat source that is cooled by the gas refrigerant when the gas refrigerant sent from the compressor (1) passes through (2) and

The heat source (2) force heat exchanger (3) from which the gaseous refrigerant after absorbing heat releases heat to the outside;

A buffer tank (4) for temporarily storing the gaseous refrigerant after releasing heat to the outside in the heat exchanger (3);

A closed circuit that connects the compressor (1), the heat source (2), the heat exchanger (3), and the buffer tank (4) in this order is configured, and the gas is connected to the closed circuit. A cooling system comprising a pipe (5) for circulating the refrigerant.

[2] The cooling system according to claim 1, further comprising another buffer tank (200) for temporarily storing the gaseous refrigerant between the compressor (1) and the heat source (2).

[3] The capacity of the buffer tank (4) is not less than the amount of the gas refrigerant discharged by the compressor (1) within a time required for the gas refrigerant to circulate once through the closed circuit. The cooling system according to 1.

[4] A supplementary pipe (8a) connected to the buffer tank (4) so that the gaseous refrigerant can be supplemented from the outside,

The cooling system according to claim 1, further comprising a discharge pipe (8b) connected to the buffer tank (4) so that the gaseous refrigerant can be discharged to the outside.

[5] The compressor (1) has a capability of discharging a larger amount of the gas refrigerant than a circulation amount of the gas refrigerant necessary for cooling the heat source (2) to a target temperature. The cooling system according to 1.

6. The cooling system according to claim 1, wherein the gaseous refrigerant includes nitrogen, oxygen, carbon dioxide, or an inert gas.

[7] The pipe (5) functions as a cooling pipe for the heat source (2),

The surface area of the cooling tubes 20 cm ² or more per heat lm ³ and is 750 cm ² or less, cooling system according to claim 1.

8. The cooling system according to claim 1, wherein the pressure loss of the gas in the heat exchanger (3) is 1Z10 or less of the pressure loss of the gas in the entire closed circuit.

[9] Separately from the closed circuit, the amount of the gas discharged by the compressor (1) after the compressor (1) is started and before the gas circulates once in the closed circuit The cooling system according to claim 1, further comprising a refrigerant supply path (200, 210, 8a) capable of supplying a refrigerant to the compressor (1).

[10] The gas refrigerant in the buffer tank (4) when the pressure of the gas refrigerant in the buffer tank (4) is approximately the upper limit of the suction pressure of the compressor (1). An exhaust valve (80b) that automatically exhausts

When the pressure of the gaseous refrigerant in the buffer tank (4) is almost the lower limit of the suction pressure of the compressor (1), the gaseous refrigerant is automatically sucked into the buffer tank (4). The cooling system according to claim 1, further comprising an intake valve (80a) for performing the operation.

[11] A compressor (1) that compresses and sends gas refrigerant other than air to a level that does not liquefy, and a device that generates heat when performing a predetermined process using a gas for plasma processing.

A plasma processing apparatus (2) cooled by the gas refrigerant when the gas refrigerant sent from the compressor (1) passes through;

A heat exchanger (3) in which the gaseous refrigerant after absorbing heat from the plasma processing device (2) releases heat to the outside;

A closed circuit that connects the compressor (1), the heat source (2), the heat exchanger (3), and the buffer tank (4) in this order is configured, and the gas is connected to the closed circuit. A pipe (5) for circulating the refrigerant,

The plasma processing system, wherein the gaseous refrigerant comprises one or more gases that do not react with the plasma processing gas.

[12] A method of operating a cooling system according to claim 1,

When the compressor (1) is started, the gaseous refrigerant in the buffer tank (4) A step of sucking the gaseous refrigerant into the buffer tank (4) by the amount of the pressure drop;

After a time longer than the time required for the gaseous refrigerant to circulate once in the closed circuit, the pressure of the gas in the buffer tank (4) is not damaged by the compressor (1). A method for operating the cooling system comprising the step of maintaining the value.