KR102370179B1 - A Single cooling system for semiconductor equipment - Google Patents

Abstract

According to the present invention, provided is a single cooling system for a semiconductor facility, which can variably select a coolant supplied to a semiconductor facility in a relatively low-, medium-, and high-temperature range to cool the same. According to the present invention, the single cooling system comprises a sub-cooler (60) using a mixed refrigerant obtained by mixing a room-temperature gas refrigerant and a low-temperature gas refrigerant as a refrigerant for cooling a coolant, and exchanging heat between a refrigerant condensed in a condenser (40) and a refrigerant passing through an evaporator (90) to additionally (secondarily) perform condensation. Also, a plurality of refrigerant circulation paths are formed between the sub-cooler (60) and the evaporator (90), and an expansion valve is installed on a plurality of a refrigerant flowing paths to flow the refrigerant passing through the sub-cooler (60) to the different refrigerant circulation paths in accordance with a low-, medium-, and high-temperature range of the coolant.

Description

A Single cooling system for semiconductor equipment

The present invention relates to a cooling system for semiconductor equipment, and more particularly, a single cooling system that flexibly responds to the required temperature condition of a coolant required for cooling semiconductor equipment and supplies coolant at relatively high temperature, medium temperature, and low temperature. It relates to a single cooling system for semiconductor equipment that can be performed with

In order to maintain or cool (freeze) semiconductor equipment such as a chuck or chamber in which a semiconductor manufacturing process is performed, a cooling system is required that controls the temperature of the coolant supplied to the semiconductor equipment. heat exchange in the evaporator to cool the coolant to the required temperature.

On the other hand, when the temperature range required for semiconductor equipment is wide and cryogenic temperatures are required, if a cooling system that uses a multi-stage compression or multi-stage expansion method of refrigerant in a single cooling cycle is applied, the pressure or load conditions will change significantly. The amount of electricity used is excessive and the amount of process coolant is increased, which in turn leads to an increase in manufacturing cost.

In consideration of this, a cooling system that applies a dual refrigeration cycle is recently used a lot. For example, in the following prior art document 1 filed and registered by the present applicant, it flexibly responds to the coolant temperature requirements required in semiconductor facilities. Thus, a two-way cooling system capable of quickly and efficiently performing a change in the supply of a coolant at a relatively high temperature and a low temperature is disclosed. The prior art can quickly and efficiently perform a change in the supply of a coolant at a relatively high temperature and a low temperature, but since a two-way cooling cycle method is applied, this also causes an increase in the overall volume of the cooling system.

In view of this point, in the following prior art document 2, a refrigeration system operated by one compressor is developed and used by using a mixed refrigerant obtained by mixing two or more refrigerants having different boiling points. In the prior art, the refrigerant that has passed through the condenser and the refrigerant that has passed through the evaporator are heat-exchanged in the heat exchanger to further condense the low-temperature refrigerant gas that has not been condensed in the condenser among the mixed refrigerants, thereby increasing the degree of supercooling of the refrigerant to increase the evaporation efficiency. there will be

However, when the refrigeration system disclosed in the prior art is applied to a semiconductor process facility, there are the following problems. In order to control the semiconductor process equipment to a desired temperature condition, the temperature of the coolant circulating in the process equipment must be adjusted, and the coolant is cooled by heat exchange with the refrigerant in the evaporator. Here, depending on the load of the coolant that exchanges heat with the mixed refrigerant in the evaporator, the pressure of the refrigeration system changes greatly, temperature control is difficult, and durability due to the very high pressure causes problems. In other words, since one expansion valve is used, the control can be done well in a section with less response to a temperature band (for example, -50 to -20℃ or 5 to 20℃), but it is difficult to control in other temperature bands, so the refrigerant Since it takes a lot or a small amount, there is a problem in that the compressor is damaged due to overcooling and overheating.

Registered Patent Publication No. 10-1923433 (Registered on November 23, 2018) Laid-open Patent Publication No. 10-2016-0148505 (published on December 26, 2016)

The present invention has been devised in view of the above points, and it is a single cooling system for semiconductor equipment that enables rapid and efficient changes in coolant supply of relatively high, medium, and low temperatures in a single cooling cycle using a mixed refrigerant. Its purpose is to provide

A single cooling system for semiconductor equipment according to the present invention for achieving the above object is a cooling system that can variably select and cool the coolant supplied to the semiconductor equipment in a relative low, medium, and high temperature range according to the cooling required temperature. , a compressor for compressing a mixed refrigerant in which a room temperature gas refrigerant and a low temperature gas refrigerant are mixed, a condenser for condensing the compressed refrigerant, an expansion valve for expanding the condensed refrigerant, and the heat of vaporization of the expanded refrigerant a cooling device including an evaporator for cooling the runt; a sub-cooler installed at the rear end of the condenser on the refrigerant circulation path to heat-exchange the refrigerant passing through the condenser with the refrigerant passing through the evaporator and further condensing; and a control unit that adjusts the opening/closing amount of the expansion valve according to the cooling required temperature of the coolant. Here, a plurality of refrigerant circulation paths are formed between the sub-cooler and the evaporator, and an expansion valve is installed on each of the plurality of refrigerant movement paths, and the controller controls the sub-cooler according to the low, medium, and high temperature range of the coolant. Controls the coarse refrigerant to move through different refrigerant circulation paths.

The expansion valve includes a low-temperature expansion valve installed on a first path between the sub-cooler and the evaporator and a high-temperature expansion valve installed on a second path between the sub-cooler and the evaporator, and on the first path and A low-temperature and high-temperature solenoid valve is installed in front of the low-temperature and high-temperature expansion valve on the second path, respectively. The control unit selectively opens or all of the low-temperature solenoid valves or high-temperature solenoid valves according to the cooling demand temperature of the coolant, so that the refrigerant that has passed through the sub-cooler is selectively introduced into the low-temperature expansion valve or high-temperature expansion valve, or can be brought in at the same time.

The high-temperature expansion valve may have a larger cross-sectional area (orifice diameter) of the refrigerant passage than the low-temperature expansion valve.

A third path is connected to the refrigerant circulation path of the evaporator and the sub-cooler so that the refrigerant that has passed through the sub-cooler can be introduced. can be installed. In addition, when the cooling required temperature of the coolant is in a high temperature range, the controller may control the high temperature pressure control solenoid valve to allow a portion of the refrigerant that has passed through the sub-cooler to flow into the high temperature pressure control expansion valve.

According to the present invention, a mixed refrigerant of a room temperature gas refrigerant and a low temperature gas refrigerant is used as a refrigerant for cooling the coolant, and the refrigerant condensed in the condenser exchanges heat with the refrigerant that has passed through the evaporator to additionally (secondary) condensate. By having a cooler, it is possible to increase the degree of supercooling of the refrigerant to increase the evaporation efficiency, and to lower the high pressure pressure of the compressor. There is this.

In addition, in order to control a wide temperature range, the refrigerant goes through the high temperature expansion valve when controlling the high temperature temperature, the low temperature expansion valve when controlling the low temperature temperature, and both expansion valves when controlling the medium temperature temperature. It is possible to solve the pressure reduction caused by the rise in the band and temperature, and there is an effect of stably controlling the temperature range of a wide section.

1 is a block diagram of a single cooling system for semiconductor equipment according to an embodiment of the present invention;
2 is a view for explaining a circulation operation of a refrigerant and a coolant when a high-temperature coolant is supplied in FIG. 1;
3 is a view for explaining a circulation operation of a refrigerant and a coolant when a low-temperature coolant is supplied in FIG. 1;
FIG. 4 is a view for explaining the circulation of a refrigerant and a coolant when a medium temperature coolant is supplied in FIG. 1 .

The above objects, features and other advantages of the present invention will become more apparent by describing preferred embodiments of the present invention in detail with reference to the accompanying drawings. Hereinafter, a single cooling system for semiconductor equipment according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The single cooling system for semiconductor equipment according to the embodiment of the present invention can control the cooling temperature of the coolant supplied to the semiconductor equipment in a wider temperature range by applying one refrigeration cycle, as well as relatively low, medium, Variable and quick change to high temperature range to allow adjustment.

In an embodiment of the present invention, the high-temperature cooling range is applicable to approximately 15 ~ 100 ℃, the medium-temperature cooling range is applicable to -20 ~ 15 ℃, low-temperature cooling range is exemplified as applicable to -50 ~ -20 ℃ However, the scope of the present invention is not necessarily limited thereto, and may be changed according to the required cooling temperature required in the semiconductor process. Also, for example, detailed temperature control in each temperature range can be controlled in detail by adjusting the amount of heat generated by the heater 120 provided in the path for supplying coolant to the semiconductor equipment, adjusting the opening degree of the expansion valve, and controlling the amount of hot gas supplied. can

Referring to FIG. 1 , a single cooling system for semiconductor equipment according to an embodiment of the present invention includes a cooling device including a compressor 10 , a condenser 40 , an expansion valve and an evaporator 90 , a sub-cooler 60 , and a control unit includes

The cooling device has a closed structure in which the refrigerant circulates, and a structure of a generally known refrigeration cycle system may be adopted. That is, the compressor 10 compresses the refrigerant, the condenser 40 condenses the compressed refrigerant, the expansion valve expands the condensed refrigerant, and the evaporator 90 uses the heat of vaporization of the expanded refrigerant to generate a coolant. to be cooled The coolant cooled by heat exchange with the refrigerant in the evaporator 90 is supplied to the semiconductor equipment.

On the other hand, the refrigerant used in the cooling system of the present invention is a mixed refrigerant in which a room temperature gas refrigerant and a low temperature gas refrigerant are mixed, for example, R13, R14, R170, R23, R290, R32 , R404A, R407C, R410A, R507, R503, R508B, R600A, etc. may be appropriately mixed and used.

The oil cooler 20 and the oil separator 30 are installed between the compressor 10 and the condenser 40, and the oil cooler 20 heat-exchanges the refrigerant that has passed through the compressor 10 with the process coolant (PCW). The oil contained in the refrigerant is condensed, and the oil separator 30 separates the oil condensed in the oil cooler 20 from the refrigerant. In other words, for example, the high-temperature refrigerant (approximately 80 to 90 ℃) compressed in the compressor is set to lower to about 50 ℃ by heat exchange with the process coolant (PCW) in the oil cooler 20, at this time, the refrigerant contained in the refrigerant. The oil is condensed to promote oil separation efficiency in the oil separator 30 . In addition, in the process of first condensing the oil contained in the refrigerant discharged from the compressor 10 over a certain level, the temperature of the refrigerant is lowered as a whole, thereby further reducing the amount of heat required for condensation in the condenser 40, ) can reduce the amount of supply, which in turn has the advantage of saving energy.

Meanwhile, in the embodiment of the present invention, a water cooling method using process cooling water (PCW) was used to cool the refrigerant in the oil cooler 20 and the condenser 40, but the scope of the present invention is not limited thereto. An air cooling method may be applied.

According to the embodiment of the present invention, the receiver 50 may be additionally installed as needed. The receiver 50 is a container for temporarily storing the refrigerant liquefied in the condenser 40, and according to the load change in the evaporator, It absorbs the change in the amount of refrigerant to make the system run smoothly, or to stop the refrigeration system or to recover and store the refrigerant when the low pressure side is repaired.

The sub-cooler 60 is installed at the rear end of the condenser 40 or the receiver 50 , and serves to additionally (secondary) condensate the refrigerant that has passed through the condenser 40 . That is, the sub-cooler 60 heat-exchanges the refrigerant that has passed through the condenser 40 with the refrigerant that has passed through the evaporator 90 to further condense it. The condensed refrigerant after passing through is condensed secondarily to a lower temperature. Accordingly, the degree of supercooling of the refrigerant can be increased, so that the evaporation efficiency of the refrigerant flowing into the evaporator can be increased, and consequently, there is an advantage that the high pressure pressure of the compressor can be lowered. That is, since a compressor of the same horsepower exhibits a greater refrigeration capacity, electricity consumption and production cost are reduced. In addition, since a single refrigeration cycle with one compressor is applied, there is an advantage in that the overall size of the system is reduced.

According to the present invention, a plurality of refrigerant circulation paths are formed between the sub-cooler 60 and the evaporator 90 , and expansion valves are respectively installed on the plurality of refrigerant movement paths. Accordingly, the control unit causes the refrigerant that has passed through the sub-cooler 60 to move through different refrigerant circulation paths and pass through different expansion valves according to the low, medium, and high temperature ranges of the coolant.

According to a preferred embodiment of the present invention, the refrigerant movement path is described as having two paths. As shown, the expansion valve includes a low-temperature expansion valve 70 installed on a first path between the sub-cooler 60 and the evaporator 90 and a second path between the sub-cooler 60 and the evaporator 90 . It includes a high-temperature expansion valve (80) installed in the. That is, the refrigerant that has passed through the sub-cooler 60 can move through two paths.

In addition, the low-temperature solenoid valve 72 and the high-temperature solenoid valve 82 are respectively installed in front of the low-temperature and high-temperature expansion valves 70 and 80 on the first and second paths to open and close the flow of flow.

As described above, as the refrigerant used in the cooling system of the present invention, a mixed refrigerant of a room temperature gas refrigerant and a low temperature gas refrigerant is used. , can be variably selected and controlled in a high temperature range. At this time, the refrigerant that has passed through the sub-cooler 60 according to each temperature range is selectively introduced into the low-temperature expansion valve 70 or the high-temperature expansion valve 80, or is simultaneously introduced can make it

Specifically, the room temperature gas refrigerant condensed at room temperature and the low temperature gas refrigerant condensed at a lower temperature than room temperature have different condensing temperatures. and the low-temperature gas refrigerant does not condense.

First, in the case of a high temperature condition (approximately 15 ~ 100 ℃), the low temperature solenoid valve 72 is closed and the high temperature solenoid valve 82 is opened, so that the refrigerant that has passed through the sub-cooler 60 flows into the high temperature expansion valve 80 (see Fig. 2). Here, the refrigerant flowing into the sub-cooler 60 through the condenser 40 is heat-exchanged with the refrigerant that has passed through the evaporator 90 and is further condensed. In the refrigerant flowing into the sub-cooler 60 through it, the low-temperature gas refrigerant does not condense and thus does not function, and thus the temperature is controlled using only the room-temperature gas refrigerant.

Next, in the case of a low temperature temperature condition (-50 ~ -20 ℃), the high temperature solenoid valve 82 is closed and the low temperature solenoid valve 72 is opened, and the refrigerant that has passed through the sub-cooler 60 is transferred to the low temperature expansion valve 70 . inflow (see FIG. 3). Here, the refrigerant flowing into the sub-cooler 60 through the condenser 40 is heat-exchanged with the refrigerant that has passed through the evaporator 90 and is further condensed. In the refrigerant flowing into the sub-cooler 60 via

And in the case of a medium temperature condition (-20 ~ 15 ℃), the high temperature solenoid valve 82 and the low temperature solenoid valve 72 are both open, so the refrigerant that has passed through the sub-cooler 60 is the high temperature expansion valve 80 and the low temperature It is branched into the expansion valve 70 and introduced (see FIG. 4). Here, the refrigerant flowing into the sub-cooler 60 through the condenser 40 is heat-exchanged with the refrigerant that has passed through the evaporator 90 and is further condensed. Since it is between the low-temperature temperature conditions, the low-temperature gas refrigerant in the refrigerant flowing into the sub-cooler 60 through the condenser 40 is in a semi-liquid state in which only a part of the low-temperature gas refrigerant is in a liquid state. will control

On the other hand, according to the present invention. A third path is connected to the refrigerant circulation path flowing into the sub-cooler 60 through the evaporator 90 so that the refrigerant that has passed through the sub-cooler 60 can flow in, and an expansion valve 150 for high-temperature pressure control is located on the third path. ) and a solenoid valve 152 for high temperature pressure control provided at the front end is installed. When the cooling demand temperature of the coolant is in a high temperature range, the control unit causes the refrigerant that has passed through the sub-cooler 60 to flow into the high-temperature expansion valve 80 as described above, and at this time, controls the solenoid valve 152 for high-temperature pressure control. Thus, a portion of the refrigerant that has passed through the sub-cooler 60 is introduced into the expansion valve 150 for high temperature pressure control.

In the high-temperature process, it receives heat while passing through the evaporator 90 and the pressure of the refrigerant gas rises. Since it is introduced into the sub-cooler 60 again, the refrigerant flowing into the sub-cooler 60 can be effectively condensed during heat exchange in the sub-cooler 60 .

On the other hand, the low-temperature expansion valve 70 and the high-temperature expansion valve 80 may be a well-known electronic expansion valve (EEV: Electric Expasion Valve) or a capillary tube driven by a control unit may be applied. Since the temperature and the evaporation pressure are different, it is desirable to make a difference in the cross-sectional area (orifice diameter) of the refrigerant passage passage.

Here, the evaporation temperature and evaporation pressure of the refrigerant passing through the high temperature expansion valve 80 in the high temperature range are greater than the evaporation temperature and evaporation pressure of the refrigerant passing through the low temperature expansion valve 70 in the low temperature temperature range, so the high temperature It is preferable that the orifice diameter of the expansion valve 80 is relatively larger than that of the low temperature expansion valve 70 .

Meanwhile, according to the present invention, in addition to the first path and the second path, a third path through which the refrigerant in the medium temperature range circulates may be additionally provided, and a solenoid valve and an expansion valve may be provided in the third path. However, even if the refrigerant is appropriately branched and supplied to the first and second paths as described above, the intended purpose may be achieved. In addition, although the temperature range was divided into three ranges, it may be divided into more subdivided ranges, and accordingly, another refrigerant circulation path may be installed, and an expansion valve and a solenoid valve may be additionally installed in the path.

The coolant cooled by heat exchange with the refrigerant in the evaporator 90 is supplied to the semiconductor equipment to cool it to a desired process temperature (refer to FIGS. 2 to 4 ).

Meanwhile, the coolant supply device 100 may be installed on the coolant path between the evaporator 90 and the semiconductor equipment. The coolant supply device 100 includes a storage tank 110 in which the coolant heat-exchanged in the evaporator 90 is stored, a heater 120 that adjusts the coolant stored in the storage tank 110 to a predetermined temperature, and a storage tank. and a circulation pump 130 for circulating and supplying the coolant stored in 110 to the semiconductor equipment and the evaporator 90 . In addition, temperature sensors T1 and T2 may be installed at the coolant inlet and outlet ends of the semiconductor equipment, respectively.

In addition, a refrigerant path may be additionally installed so that the refrigerant that has passed through the oil separator 30 flows into the evaporator 90 , and a hot gas solenoid valve 142 and a hot gas valve 140 may be installed on this path. Accordingly, the high-temperature, high-pressure refrigerant that has passed through the compressor 10 and before passing through the condenser 40 is supplied to the evaporator to control the temperature of the coolant.

A control unit (not shown) controls the operation of each component of the cooling system of the present invention. In particular, according to the cooling demand temperature of the semiconductor facility, based on the temperature value sensed from the temperature sensors T1 and T2, the low temperature solenoid valve ( 72) or the high-temperature solenoid valve 82 is selectively opened or both are opened so that the refrigerant passing through the sub-cooler 60 is selectively introduced into the low-temperature expansion valve 70 or the high-temperature expansion valve 80 or simultaneously to control the inflow. In addition, the controller can finely control the temperature by controlling the flow rate of the refrigerant by adjusting the opening amounts of the low-temperature expansion valve 70 and the high-temperature expansion valve 80 . In addition, the controller may control the opening and closing of the hot gas solenoid valve 142 and finely adjust the temperature of the coolant by adjusting the opening amount of the hot gas valve 140 .

Hereinafter, a relatively high temperature, medium temperature, and low temperature temperature control process of a semiconductor facility according to coolant circulation according to an embodiment of the present invention, and a refrigerant circulation process of a single cooling system for this will be described. Here, the relative temperature can be controlled based on the temperature of the coolant that is heat-exchanged in the evaporator 90 and flows into the semiconductor equipment.

On the other hand, as described above, the refrigerant used in the present invention is a mixed refrigerant in which a room temperature gas refrigerant and a low temperature gas refrigerant are mixed.

First, with reference to FIG. 2 , the circulation process of the refrigerant and the coolant when the high temperature cooling range of 15 to 100° C. is schematically controlled will be described.

The refrigerant compressed in the compressor 10 passes through the oil cooler 20 and the oil separator 30, and the high-temperature refrigerant containing the oil compressed in the compressor 10 is transferred to the process coolant (PCW) in the oil cooler 20. The temperature is lowered by heat exchange with the oil, and at this time, the oil is also condensed and the oil is filtered in the oil separator 30 .

The refrigerant flowing into the condenser 40 through the oil separator 30 is condensed by heat exchange with the process cooling water (P.C.W), and the condensed refrigerant flows through the receiver 50 and then into the sub-cooler 60 . Here, as described above, the refrigerant is a mixture of a room temperature gas refrigerant and a low temperature gas refrigerant. Only the room temperature gas refrigerant is condensed while passing through the condenser 40 , and the low temperature gas refrigerant is not condensed. The refrigerant flowing into the sub-cooler 60 through the condenser 40 exchanges heat with the refrigerant that has passed through the evaporator 90 to be further condensed.

At this time, under the control of the controller, the low-temperature solenoid valve 72 is closed and the high-temperature solenoid valve 82 is opened, and the refrigerant that has passed through the sub-cooler 60 flows into the high-temperature expansion valve 80 . The refrigerant that has passed through the high-temperature expansion valve 80 flows into the evaporator 90 to exchange heat with the coolant flowing into the semiconductor equipment, and the refrigerant that has passed through the evaporator 90 flows back into the sub-cooler 60 as described above. It exchanges heat with the refrigerant that has passed through the condenser 40 to further condense the refrigerant.

The refrigerant passing through the sub-cooler 60 flows into the compressor 10, and the refrigerant circulating in this way constitutes a closed circuit.

On the other hand, the coolant used for temperature control in the semiconductor facility is recovered and heat-exchanged with the refrigerant while passing through the evaporator 90 to be cooled, and the process of being supplied to the facility on the peninsula by the cooling water supply device 100 is repeated.

Next, with reference to FIG. 3 , the circulation process of the refrigerant and the coolant when controlled in the low-temperature cooling range of approximately -50 to -20°C will be described.

The process in which the refrigerant compressed in the compressor 10 passes through the oil cooler 20 , the oil separator 30 , the condenser 40 , the receiver 50 , and the sub-cooler 60 is the same as the process in the high temperature range above. .

As described above, only the room temperature gas refrigerant is condensed while passing through the condenser 40 , and the low temperature gas refrigerant is not condensed. The refrigerant flowing into the sub-cooler 60 through the condenser 40 is It is further condensed by heat exchange with the refrigerant of

At this time, under the control of the controller, the high-temperature solenoid valve 82 is closed and the low-temperature solenoid valve 72 is opened, and the refrigerant that has passed through the sub-cooler 60 flows into the low-temperature expansion valve 70 . The refrigerant that has passed through the low-temperature expansion valve 70 flows into the evaporator 90 and exchanges heat with the coolant flowing into the semiconductor equipment, and the refrigerant heat-exchanged in the evaporator 90 flows back into the sub-cooler 60 as described above. Likewise, heat exchange with the refrigerant flowing into the sub-cooler 60 through the condenser 40 serves to further condense the refrigerant.

The coolant circulation process is the same as the above-mentioned high temperature temperature range conditions.

Finally, with reference to FIG. 4 , the circulation process of the refrigerant and the coolant when controlled in a medium temperature cooling range having a temperature of -20 to 15° C. will be described.

The process in which the refrigerant compressed in the compressor 10 passes through the oil cooler 20, the oil separator 30, the condenser 40, the receiver 50, and the sub-cooler 60 is the same as the process of the previous high and low temperature range same

As described above, while passing through the condenser 40, only the room temperature gas refrigerant is condensed and the low temperature gas refrigerant is not condensed. is condensed, and the low-temperature gas refrigerant is partially condensed. That is, the low-temperature gas refrigerant is in a semi-liquid state.

At this time, both the high-temperature solenoid valve 82 and the low-temperature solenoid valve 72 are opened, and accordingly, the refrigerant that has passed through the sub-cooler 60 is branched into the high-temperature expansion valve 80 and the low-temperature expansion valve 70 and introduced. The controller adjusts the temperature by adjusting the opening degrees of the high-temperature expansion valve 80 and the low-temperature expansion valve 70 .

The refrigerant that has passed through the high-temperature expansion valve 80 and the low-temperature expansion valve 70 flows into the evaporator 90 and exchanges heat with the coolant flowing into the semiconductor equipment, and the refrigerant heat-exchanged in the evaporator 90 is again transferred to the sub-cooler 60 ) and exchanges heat with the refrigerant flowing into the sub-cooler 60 through the condenser 40 as described above, thereby further condensing the refrigerant.

The coolant circulation process is the same as the above high and low temperature range conditions.

As described above, according to the present invention, a mixed refrigerant in which a room temperature gas refrigerant and a low temperature gas refrigerant are mixed is used as a refrigerant for cooling the coolant, and the refrigerant condensed in the condenser exchanges heat with the refrigerant that has passed through the evaporator and is additionally (secondary) condensed By providing a sub-cooler, it is possible to increase the degree of supercooling of the refrigerant to increase the evaporation efficiency, and has the advantage of lowering the high pressure pressure of the compressor. As a result, more refrigeration capacity is exhibited with the same horsepower compressor, so electricity consumption and production cost are reduced.

In addition, in order to control a wide range, the refrigerant goes through the high temperature expansion valve when controlling the high temperature temperature, the low temperature expansion valve when controlling the low temperature temperature, and both expansion valves when controlling the medium temperature temperature. There is an advantage that the adjustment is more convenient.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. That is, a person of ordinary skill in the art to which the present invention pertains can make numerous changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications are possible. Equivalents are to be considered as falling within the scope of the present invention.

10. Compressor 20. Oil cooler
30. Oil Separator 40. Condenser
60. Sub cooler 70. Low temperature expansion valve
72. Low temperature solenoid valve 80. High temperature expansion valve
82. High temperature solenoid valve 90. Evaporator
100. Coolant supply 140. Hot gas valve
150. Expansion valve for high temperature pressure control

Claims (4)

As a cooling system that can variably select and cool the coolant supplied to semiconductor equipment into a relatively low, medium, and high temperature range according to the cooling required temperature,
A compressor for compressing a mixed refrigerant in which a room temperature gas refrigerant and a low temperature gas refrigerant are mixed, a condenser for condensing the compressed refrigerant, an expansion valve for expanding the condensed refrigerant, and the heat of vaporization of the expanded refrigerant a cooling device comprising an evaporator to cool the;
a sub-cooler installed at the rear end of the condenser on the refrigerant circulation path to heat-exchange the refrigerant passing through the condenser with the refrigerant passing through the evaporator to further condense; and,
a control unit that adjusts the opening/closing amount of the expansion valve according to the cooling required temperature of the coolant;
A plurality of refrigerant circulation paths are formed between the sub-cooler and the evaporator, and an expansion valve is installed on each of the plurality of refrigerant circulation paths, and the control unit passes through the sub-cooler according to the low, medium, and high temperature range of the coolant. Control the refrigerant to move through different refrigerant circulation paths,
The expansion valve includes a low-temperature expansion valve installed on a first path between the sub-cooler and the evaporator and a high-temperature expansion valve installed on a second path between the sub-cooler and the evaporator,
Low-temperature and high-temperature solenoid valves are installed in front of the low-temperature and high-temperature expansion valves on the first path and on the second path, respectively,
The control unit selectively opens or all of the low-temperature solenoid valves or high-temperature solenoid valves according to the cooling demand temperature of the coolant, so that the refrigerant that has passed through the sub-cooler is selectively introduced into the low-temperature expansion valve or high-temperature expansion valve, or to flow in at the same time,
A third path is connected to the refrigerant circulation path of the evaporator and the sub-cooler so that the refrigerant that has passed through the sub-cooler can be introduced, and an expansion valve for high-temperature pressure control and a solenoid valve for high-temperature pressure control provided in the front stage on the third path. installed,
When the cooling demand temperature of the coolant is in a high temperature range, the control unit controls the high temperature pressure control solenoid valve so that a portion of the refrigerant that has passed through the sub-cooler flows into the high-temperature pressure control expansion valve, which passes through the sub-cooler. A portion of the refrigerant is combined with the refrigerant that has passed through the evaporator while passing through the third path, and then passes through the sub-cooler again.
delete The method of claim 1,
The single cooling system for semiconductor equipment, characterized in that the high-temperature expansion valve has a larger cross-sectional area (orifice diameter) of the refrigerant passage than the low-temperature expansion valve.
delete

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