KR20240005425A - Cryogenic cooling system - Google Patents

Abstract

A cryogenic cooling system according to an embodiment of the present invention includes a first low-temperature cycle in which a first mixed refrigerant circulates; A second low-temperature cycle in which a second mixed refrigerant circulates; a bridge heat exchanger configured to exchange heat between the first mixed refrigerant of the first low-temperature cycle and the second mixed refrigerant of the second low-temperature cycle; and a plurality of channel units connected in parallel to the secondary low temperature cycle, each having a different minimum temperature required for operation.

Description

Cryogenic cooling system {Cryogenic cooling system}

The present invention relates to cryogenic cooling systems.

Generally, the temperature of semiconductor processing equipment increases due to thermal load during the semiconductor manufacturing process. Here, a cooling system in which low-temperature cooling fluid circulates can be provided to recover the thermal load. Accordingly, the cooling system can be provided to control the temperature required by the semiconductor processing equipment while removing heat generated from the semiconductor processing equipment.

The cooling system can be classified into types depending on the method of implementing a refrigeration cycle to cool the cooling fluid to the target temperature. For example, the cooling system may be divided into a two-way refrigeration system, a three-way refrigeration system, a cascade refrigeration system, a J-T refrigeration system, etc.

The binary refrigeration system can form two individual refrigeration cycles that perform compression, condensation, expansion, and evaporation processes depending on the type of refrigerant. Generally, the first refrigerant circulating in the first compressor transfers heat to the second refrigerant circulating in the second compressor and is condensed. Additionally, the first refrigerant may evaporate by absorbing heat from a fluid (eg, brine) circulating in semiconductor processing equipment. And the second refrigerant may exchange heat with the first refrigerant and evaporate.

When the semiconductor process requires an extremely low temperature lower than -70 degrees Celsius (°C), the general binary refrigeration system described above has difficulty in forming extremely low temperatures due to the characteristics of the refrigerant, and the low pressure is very low, so the cycle is difficult. Because it becomes unstable, there is a problem that it is difficult to satisfy the above-mentioned required temperature.

Here, a cooling system that can satisfy the extremely low temperature required in the semiconductor process may be called a “cryogenic cooling system.”

A typical three-way refrigeration system can form three individual refrigeration cycles that perform compression, condensation, expansion, and evaporation processes depending on the type of refrigerant. In other words, the three-way refrigeration system has the problem of increasing the volume and configuration because it forms more individual refrigeration cycles than the binary refrigeration system. The complexity of such a three-way refrigeration system makes it unsuitable for use in semiconductor processing equipment, and it has limitations in temperature control due to difficulty in maintaining thermal balance between refrigerants. Ultimately, the three-way refrigeration system also has the problem of forming extremely low temperatures due to limitations in condensation.

A cascade refrigeration system, in which multiple evaporators are connected to one compressor in cascade, generally involves compressing mixed refrigerants of three or more types of refrigerants together in one compressor and then refrigerating them separately according to the characteristics of each refrigerant. It is configured to be separated in the evaporator. However, this cascade refrigeration system has the problem of becoming very large in size because each type of refrigerant is separated after being compressed by a single compressor.

Moreover, the existing cascade refrigeration system requires a compressor with a large capacity, so electricity consumption is relatively high, and there is an unstable problem of forming thermal balance between refrigerants and achieving the target temperature of cryogenic temperature.

In addition, when trying to create extremely low temperatures using a single refrigerant, the intake temperature is relatively low, so a method to compensate for this is needed, which causes the problem of complicating the cooling system configuration and increasing the size.

Meanwhile, as semiconductor processes become increasingly detailed and integrated, control temperature characteristics in each individual process (“channel”) are required to vary over a wide range from extremely high temperatures to extremely low temperatures.

However, as mentioned above, the existing cooling system method is disadvantageous in forming cryogenic temperatures and is used only for one individual process, so it cannot satisfy all the control temperature characteristics (range from high temperature to low temperature) required differently for each individual process. There are limitations in providing a cooling fluid that can be used, and due to its structure, it is very difficult to use it for multiple processes (“channels”) simultaneously.

In addition, when a conventional cooling system (or refrigerator) is used for only one individual process (“channel”), from the perspective of the entire semiconductor process, a cycle to generate low temperature is added for each of several independent processes, increasing the overall size. There is a problem. In other words, there is a problem of relatively low economy and efficiency.

KR 10-2341074 B1, cryogenic freezer KR 10-2019-0125892 A, cryogenic semiconductor chiller device KR 10-1923433 B1, two-way cooling system for cooling semiconductor components KR 10-2153016 B1, cryogenic chiller

The purpose of the present invention is to provide a cryogenic cooling system that can solve the problems of the conventional refrigeration system described above.

Another object of the present invention is to provide a cryogenic cooling system that can satisfy the high to low temperature ranges differently required for each individual process (hereinafter referred to as “channel”) in the semiconductor process with one cooling fluid cycle. It is done.

Another object of the present invention is to provide a cryogenic cooling system that can be used in multiple channels and at the same time relatively reduce the size of the overall system.

In order to achieve the above object, a cryogenic cooling system according to an embodiment of the present invention includes a first low-temperature cycle in which a first mixed refrigerant circulates; A second low-temperature cycle in which a second mixed refrigerant circulates; a bridge heat exchanger configured to exchange heat between the first mixed refrigerant of the first low-temperature cycle and the second mixed refrigerant of the second low-temperature cycle; and a plurality of channel units connected in parallel to the secondary low temperature cycle, each having a different minimum temperature required for operation.

Additionally, the secondary low-temperature cycle may include a plurality of evaporators connected in series through which the secondary mixed refrigerant sequentially passes.

In addition, each of the plurality of channel parts is connected one to one to exchange heat with one of the plurality of evaporators, and the secondary mixed refrigerant and the coolant circulating through each of the plurality of channel parts are connected one to one to exchange heat in the evaporator connected one to one. You can.

Additionally, the first evaporator among the series-connected evaporators may be connected to the channel portion having the lowest minimum temperature among the plurality of channel portions.

Additionally, the last evaporator among the series-connected evaporators may be connected to enable heat exchange with the channel portion having the highest minimum temperature among the plurality of channel portions.

In addition, the plurality of channel units may be connected one-to-one to the plurality of evaporators so that the evaporation temperature of the secondary mixed refrigerant, which changes as it sequentially passes through the plurality of evaporators, matches the minimum temperature required for operation of each of the plurality of channel parts. there is.

In the bridge heat exchanger, at least a portion of the first mixed refrigerant may be evaporated and at least a portion of the second mixed refrigerant may be condensed through heat exchange.

Additionally, the first low-temperature cycle includes a first compressor through which the first mixed refrigerant circulates; a first condenser in which the first mixed refrigerant discharged from the first compressor is condensed; a recuperator configured to exchange heat between the first mixed refrigerant discharged from the first condenser and the first mixed refrigerant discharged from the bridge heat exchanger; And it may include a first expansion valve installed between the bridge heat exchanger and the recuperator to expand the refrigerant discharged from the recuperator and introduced into the bridge heat exchanger.

In addition, the primary mixed refrigerant flowing into the first condenser exchanges heat through the primary cooling pipe through which cooling water or room temperature refrigerant circulates, and when room temperature refrigerant circulates through the primary cooling pipe, the primary cooling pipe is characterized in that it is an evaporation area of the refrigeration cycle of the room temperature refrigerant.

In addition, the second low-temperature cycle includes a second compressor through which the second mixed refrigerant circulates; a second condenser in which the refrigerant discharged from the second compressor is condensed; And it may further include a second expansion valve that expands the refrigerant discharged from the bridge heat exchanger and is installed between the first evaporator among the plurality of evaporators connected in series and the bridge heat exchanger to expand the secondary mixed refrigerant.

Additionally, the bridge heat exchanger may be configured to exchange heat between the secondary mixed refrigerant that has passed through the second condenser and the primary mixed refrigerant that has passed through the first expansion valve.

Additionally, the secondary mixed refrigerant flowing into the second condenser may be heat exchanged through cooling pipes through which cooling water, room temperature refrigerant, or a mixed refrigerant with a relatively higher boiling point than the secondary mixed refrigerant circulates.

In addition, the plurality of evaporators include a first evaporator that introduces the secondary mixed refrigerant that has passed through the second expansion valve and exchanges heat with the coolant of one channel portion; a second evaporator connected in series with the first evaporator and receiving the secondary mixed refrigerant discharged from the first evaporator to exchange heat with the coolant of the other channel; And it may include a third evaporator connected in series with the second evaporator and introducing the secondary mixed refrigerant discharged from the second evaporator to exchange heat with the coolant of another channel portion.

In addition, the secondary low-temperature cycle includes a first connection pipe extending from the first evaporator to the second evaporator to guide sequential evaporation of the secondary mixed refrigerant; And it may further include a second connection pipe extending from the second evaporator to the third evaporator to guide sequential evaporation of the secondary mixed refrigerant.

Additionally, the plurality of channel units include: a first channel unit that exchanges heat with the first evaporator; a second channel unit having a higher minimum temperature than the first channel unit and exchanging heat with the second evaporator; And it may include a third channel unit that has a higher minimum temperature than the second channel unit and exchanges heat with the third evaporator.

Additionally, the maximum temperature required for operation of the first to third channel units may be set to the same temperature.

In addition, the plurality of channel units each include an inlet pipe extending from the coolant outlet of the evaporator to the inlet of the channel unit to introduce the coolant that has passed through the evaporator; a storage tank in which the coolant is stored; a recovery pipe extending from the outlet of the channel unit to the storage tank to recover coolant; a pump for circulating the coolant; A channel valve that controls the flow direction of coolant discharged from the pump; a channel branch pipe extending from one outlet end of the channel valve to the coolant inlet of the evaporator; And it may include a channel combination pipe extending straight from the other outlet end of the channel valve to a point of the introduction pipe.

In addition, the first mixed refrigerant and the second mixed refrigerant include at least one primary low-temperature refrigerant selected from R116, R23, and R508B; And it may include at least one secondary low-temperature refrigerant among R1150, R14, and R50.

According to the present invention, the first low-temperature cycle in which the ultra-low temperature mixed refrigerant passes through the recuperator and the second low-temperature cycle in which a separate cryogenic mixed refrigerant circulates are heat exchanged by the bridge heat exchanger defined in the present invention, thereby forming the second low-temperature cycle. It has the advantage of being able to reach a condensation temperature of approximately -70 degrees Celsius (°C).

According to the present invention, the number of cycles is relatively reduced and the number of parts is reduced compared to the existing low-temperature cooling system configured to achieve the same performance, so there is an advantage in that economics and efficiency are improved and the size of the overall system can be reduced.

According to the present invention, there is an advantage of enabling simultaneous operation of multiple channels that require extremely low temperatures with relatively few components and a low-temperature cycle.

1 is a diagram showing the configuration of a cooling system according to an embodiment of the present invention.
Figure 2 is a diagram illustrating an operation in which refrigerant and coolant circulate in a cooling system according to an embodiment of the present invention.
Figure 3 is a diagram showing a Ph diagram for the second low temperature cycle (SC) of the cooling system according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing embodiments of the present invention, if detailed descriptions of related known configurations or functions are judged to impede understanding of the embodiments of the present invention, the detailed descriptions will be omitted.

Additionally, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. When a component is described as being "connected," "coupled," or "connected" to another component, that component may be directly connected or connected to that other component, but there is no need for another component between each component. It should be understood that may be “connected,” “combined,” or “connected.”

Figure 1 is a diagram showing the configuration of a cooling system according to an embodiment of the present invention, and Figure 2 is a diagram showing an exemplary operation of the refrigerant and coolant circulating in the cooling system according to an embodiment of the present invention. am.

Referring to Figures 1 and 2, the cryogenic cooling system according to an embodiment of the present invention is a first low temperature cycle (FC) in which a first mixed refrigerant circulates. It may include a secondary low temperature cycle (SC) in which a second mixed refrigerant circulates, and a bridge heat exchanger 300 in which heat is exchanged between the first low temperature cycle (FC) and the second low temperature cycle (SC).

Here, the first mixed refrigerant and the second mixed refrigerant are defined as a refrigerant capable of forming extremely low temperatures. For example, the first mixed refrigerant and/or the second mixed refrigerant may include at least one of primary low-temperature refrigerants such as R116, R23, and R508B that can be condensed at the evaporation temperature of the room temperature refrigerant, and the primary low-temperature refrigerant. It may be a refrigerant mixed with at least one of secondary low-temperature refrigerants such as R1150, R14, and R50 that can be condensed at an evaporation temperature of.

The room temperature refrigerant is a refrigerant that can be condensed into air or cooling water and may include R134a, R404a, R410a, R32, etc.

The primary low-temperature refrigerant may be condensed by the room-temperature refrigerant when the room-temperature refrigerant is condensed by air or cooling water and then goes through an expansion process and reaches the evaporation temperature of the predetermined section. Therefore, since the cryogenic cooling system according to an embodiment of the present invention is provided with a recuperator 30 and a bridge heat exchanger 300, the primary low-temperature refrigerant condensed by the room temperature refrigerant and the primary low-temperature refrigerant are condensed by the primary low-temperature refrigerant. The refrigerant mixed with the condensed secondary low-temperature refrigerant (the first mixed refrigerant and the second mixed refrigerant) may be formed to circulate through a first low-temperature cycle (FC) and a second low-temperature cycle (SC).

Meanwhile, the first low temperature cycle (FC) includes a first compressor 10 in which the first mixed refrigerant circulates, a first condenser 20 in which the refrigerant discharged from the first compressor is condensed, and the refrigerant discharged from the first condenser It may include a recuperator 30 and a first expansion valve 40 through which the refrigerant discharged from the bridge heat exchanger 300 exchanges heat.

The first compressor 10 can compress the first mixed refrigerant described above. The refrigerant compressed in the first compressor 10 may flow into the first condenser 20 through the first pipe 15. The refrigerant compressed in the first compressor may be in a gaseous state of relatively high temperature and high pressure.

The first pipe 15 may extend from the discharge side of the first compressor 10 to the refrigerant inlet of the first condenser 20.

In addition, the refrigerant flowing into the first condenser through the first pipe 15 may exchange heat with the fluid flowing from the first condenser 20 through the primary cooling pipe 5 and condense.

Here, the fluid circulating in the primary cooling pipe 5 may be cooling water or room temperature refrigerant. For example, the primary cooling pipe 5 may be an evaporation area of a refrigeration cycle in which the above-described room temperature refrigerant circulates.

In the first condenser 30, the primary low-temperature refrigerant among the first mixed refrigerants may be condensed in the evaporation temperature section of the fluid circulating in the primary cooling pipe 5. That is, the first low-temperature refrigerant among the first mixed refrigerants may be in a liquid phase while passing through the first condenser 20. At this time, the secondary low-temperature refrigerant among the first mixed refrigerants can maintain a gaseous state even after passing through the first condenser 20.

The primary low-temperature refrigerant in the liquid state and the secondary low-temperature refrigerant in the gaseous state may flow into the second pipe 25 extending from the first condenser 20 to the recuperator 30. For example, the second pipe 25 may extend from the refrigerant outlet (not shown) of the first condenser 30 to the inlet port (not shown) of the recuperator 30.

The recuperator 30 may be configured to exchange heat between the refrigerant introduced through the second pipe 25 and the refrigerant passing through the bridge heat exchanger 300.

For example, the recuperator 30 has an inlet port to which the second pipe 25 is connected and a discharge port (not shown) to which the third pipe 35 where the first expansion valve 40 is installed is connected. In addition, the recuperator 30 has a recovery inlet port (not shown) through which the refrigerant passing through the bridge heat exchanger 300 flows and a recovery discharge port (not shown) for discharge to the first compressor 10. Poetry) can also be formed.

That is, the refrigerant flowing in through the second pipe 25 flows through the recovery inlet port and the recovery outlet port while flowing inside the recuperator 30 along a flow path formed from the inlet port to the discharge port. Heat can be exchanged with the flowing refrigerant.

In detail, the condensed primary low-temperature refrigerant among the primary mixed refrigerants flowing into the inlet port may exchange heat with the evaporated primary mixed refrigerant through the bridge heat exchanger 3000, thereby further lowering the condensation temperature, and the inlet Among the primary mixed refrigerants flowing into the port, the secondary low-temperature refrigerant, which maintains a gaseous state, passes through the bridge heat exchanger (30) and exchanges heat with the evaporated primary mixed refrigerant, reaching the condensation temperature range and condensing. there is.

The third pipe 35 on which the first expansion valve 40 is installed can connect the recuperator 30 and the bridge heat exchanger 300. For example, the third pipe 35 may extend from the discharge port to the first mixed refrigerant inlet (not shown) of the bridge heat exchanger 300. And the third pipe 35 can guide the refrigerant that has passed through the recuperator 30 to flow into the bridge heat exchanger 300.

The first expansion valve 40 may include an electronic expansion valve (EEV).

The first mixed refrigerant, that is, the condensed primary and secondary low-temperature refrigerant, which passes through the recuperator 30 and flows into the third pipe 35, expands while passing through the first expansion valve 40. You can. And the expanded first mixed refrigerant may flow into the bridge heat exchanger 300 through the first mixed refrigerant inlet.

The bridge heat exchanger 300 may form a first mixed refrigerant inlet to which the third pipe 35 is connected and a first mixed refrigerant outlet (not shown) to which the fourth pipe 45 is connected.

The bridge heat exchanger 300 performs heat exchange between the primary mixed refrigerant introduced through the third pipe 35 and the secondary mixed refrigerant passed through the second condenser 200 of the second low temperature cycle (SC), which will be described later. It can be formed as much as possible.

At this time, the first mixed refrigerant flowing into the bridge heat exchanger 300 through the third pipe 35 may evaporate by receiving heat from the first mixed refrigerant. Accordingly, the secondary low-temperature refrigerant among the first mixed refrigerants may flow into the fourth pipe 45 in a gaseous state. Meanwhile, since the first low-temperature refrigerant among the first mixed refrigerants has a relatively higher evaporation temperature than the second low-temperature refrigerant, it evaporates only part of the first mixed refrigerant or remains in a liquid state through heat exchange with the second mixed refrigerant, and enters the fourth pipe. It can flow into (45).

The fourth pipe 45 may extend from the first mixed refrigerant outlet of the bridge heat exchanger 300 to the recovery inlet port of the recuperator 30.

As described above, some of the refrigerant flowing into the fourth pipe 45 maintains a liquid state and therefore has a lower temperature than the refrigerant flowing into the recuperator 30 through the second pipe 25. Therefore, the refrigerant flowing into the recuperator 30 through the fourth pipe 45 may evaporate while exchanging heat with the refrigerant flowing into the recuperator 30 through the second pipe 25. there is. For example, the primary low-temperature refrigerant that has not been evaporated in the bridge heat exchanger 300 may be evaporated through heat exchange in the recuperator 30.

In the end, the primary mixed refrigerant flowing into the recuperator (30) through the fourth pipe (45) is discharged to the fifth pipe (55) in a gaseous state?? It can be recovered to the first compressor 10. For example, the fifth pipe 55 may extend from the recovery outlet port of the recuperator 30 to the first compressor 10.

The second low temperature cycle (SC) is performed in a second compressor 100 in which a second mixed refrigerant circulates, a second condenser 200 in which the refrigerant discharged from the second compressor is condensed, and the bridge heat exchanger 300. A second expansion valve 400 that expands the discharged refrigerant, and a plurality of evaporators (500, 600, 700) connected in series to heat exchange the refrigerant passing through the second expansion valve 400 with a coolant circulating through a plurality of channel cycles. It can be included.

The second compressor 100 can compress the second mixed refrigerant described above. The refrigerant compressed in the second compressor 100 may flow into the second condenser 200 through the first guide pipe 110. The refrigerant compressed in the second compressor may be in a gaseous state of relatively high temperature and high pressure.

The first guide pipe 110 may extend from the discharge side of the second compressor 100 to the refrigerant inlet of the second condenser 200. In addition, the refrigerant flowing into the second condenser through the first guide pipe 110 may exchange heat with the fluid flowing from the second condenser 200 through the secondary cooling pipe 6 and condense.

Here, the fluid circulating in the secondary cooling pipe 6 may be cooling water, room temperature refrigerant, or a mixed refrigerant whose boiling point is relatively higher than that of the secondary mixed refrigerant. For example, the secondary cooling pipe 6 may be an evaporation area of a refrigeration cycle in which the above-described room temperature refrigerant circulates.

In the second condenser 200, the first low-temperature refrigerant among the second mixed refrigerants may be condensed in the evaporation temperature section of the fluid circulating in the secondary cooling pipe 6. That is, the first low-temperature refrigerant among the second mixed refrigerants may become liquid while passing through the second condenser 200. At this time, the secondary low-temperature refrigerant of the second mixed refrigerant can maintain a gaseous state even after passing through the second condenser 200.

The primary low-temperature refrigerant in the liquid state and the secondary low-temperature refrigerant in the gaseous state may flow into the second guide pipe 210 extending from the second condenser 200 to the bridge heat exchanger 300. there is. For example, the second guide pipe 210 may extend from the refrigerant outlet (not shown) of the second condenser 200 to the second mixed refrigerant inlet (not shown) of the bridge heat exchanger 300.

The secondary mixed refrigerant flowing into the bridge heat exchanger 300 may be condensed by heat exchange with the first mixed refrigerant of the first low temperature cycle (SC), as described above. For example, the secondary low-temperature refrigerant of the second mixed refrigerant may be condensed into a liquid phase in the bridge heat exchanger 300.

The second mixed refrigerant condensed in the bridge heat exchanger 300 may flow into the third guide pipe 310 where the second expansion valve 400 is installed. For example, the third guide pipe 310 may extend from the secondary mixed refrigerant outlet (not shown) of the bridge heat exchanger 300 to the inlet port of the first evaporator 500 among the plurality of evaporators 500, 600, and 700. there is.

The second expansion valve 400 is installed on the third guide pipe 310 to expand the secondary mixed refrigerant. For example, the second expansion valve 400 may include an electronic expansion valve (EEV).

The plurality of evaporators (500, 600, and 700) may be formed so that the secondary mixed refrigerant that has passed through the second expansion valve (400) passes serially or sequentially.

That is, the plurality of evaporators 500, 600, and 700 connected in series can be formed so that coolant required for semiconductor processing equipment and/or individual semiconductor processing (hereinafter referred to as channel portion) passes in parallel and exchanges heat. Here, the coolant may include brine.

In detail, the plurality of evaporators (500, 600, 700) are a first evaporator (310), which is coupled to the refrigerant inlet and introduces the expanded secondary mixed refrigerant to exchange heat with the coolant of one channel cycle (1000). 500), a second evaporator (600) connected in series with the first evaporator (500) and introducing the secondary mixed refrigerant discharged from the first evaporator (500) to exchange heat with the coolant of another channel cycle (2000) ) and a third evaporator (700) connected in series with the second evaporator (600) and introducing the secondary mixed refrigerant discharged from the second evaporator (600) to exchange heat with the coolant of another one channel cycle (3000). ) may include.

According to this, the secondary mixed refrigerant evaporates as its temperature changes as it passes through the first to third evaporators (500, 600, and 700), and a plurality of channel cycles with different required temperature characteristics change during the evaporation process of the secondary mixed refrigerant. It can be connected to an evaporator (500, 600, 700) tailored to each lowest temperature section to sequentially match the temperature.

Therefore, by utilizing the temperature change of the secondary mixed refrigerant passing through the evaporators (500, 600, 700) connected in series to exchange heat with the coolant circulating in each channel cycle, separate and independent cooling for coolant cooling for each channel cycle is achieved. There is no need to add cycles, the size of the cooling system in the semiconductor process can be minimized, and efficiency can be maximized.

In addition, the second low temperature cycle (SC) is a first connection pipe 550 connecting the first evaporator 500 and the second evaporator 600 in series, and the second evaporator 600 and the third evaporator It may further include a second connection pipe 650 that connects 700 in series.

The first connection pipe 550 may extend from the refrigerant outlet of the first evaporator 500 to the refrigerant inlet of the second evaporator 600. Accordingly, the refrigerant that has passed through the first evaporator 500 is introduced into the second evaporator 600 and can exchange heat with the coolant of another channel cycle 2000.

The second connection pipe 650 may extend from the refrigerant outlet of the second evaporator 600 to the refrigerant inlet of the third evaporator 700. Accordingly, the refrigerant that has passed through the second evaporator 600 is introduced into the third evaporator and can exchange heat with the coolant of another channel cycle 3000.

Meanwhile, the secondary mixed refrigerant evaporated after passing through the plurality of evaporators (500, 600, and 700) may flow into the fourth guide pipe (750).

The fourth guide pipe 750 extends from the outlet port of the last evaporator 700 to the second compressor 100 so that the secondary mixed refrigerant that has passed through the evaporators 500, 600, and 700 is recovered to the second compressor 100. You can. For example, the fourth guide pipe 750 may extend from the outlet port of the third evaporator 700 to the suction port of the second compressor 100. Therefore, the secondary mixed refrigerant that has passed through the last evaporator (700) can be recovered to the second compressor (100) in an evaporated state.

In addition, the secondary mixed refrigerant recovered from the secondary compressor 100 may be sucked in in a superheated state while passing through the plurality of evaporators. (see Figure 3)

The cryogenic cooling system is formed to correspond to a plurality of evaporators (500, 600, 700) connected in series in the secondary cold cycle (SC), and has a plurality of channels through which coolant circulating in each evaporator (500, 600, 700) exchanges heat. Additional cycles may be included.

Each of the multiple channel cycles may have a different minimum temperature required for operation. And, among the plurality of channel cycles, the channel cycle with the lowest minimum temperature may be connected one-to-one with the first evaporator 500 of the second low-temperature cycle (SC) for heat exchange. Additionally, the channel cycle with the highest minimum temperature among the plurality of channel cycles may be connected one-to-one with the last evaporator 700 of the second low-temperature cycle (SC) for heat exchange.

Additionally, the plurality of channel cycles may be connected in a one-to-one correspondence with the number of evaporators (500, 600, 700) connected in series. Meanwhile, the channel cycle according to the embodiment of the present invention describes three channel cycles correspondingly formed for each of the three series-connected evaporators (500, 600, and 700), but is not limited thereto.

The channel cycle according to an embodiment of the present invention transfers the coolant that has passed through the channel parts (1000, 2000, 3000), where individual processes in the semiconductor process are performed, and the evaporators (500, 600, 700) to the channel parts (1000, 2000, 3000). Introducing pipes (1400, 2400, 3400) extending from the coolant outlet of the evaporator (500, 600, 700) to the inlet of the channel section (1000, 2000, 3000) so that the coolant flowing through the channel section is stored, and a storage tank in which the coolant circulating in the channel section is stored. (1100, 2100, 3100), a recovery pipe extending from the outlet of the channel unit to the storage tank to recover the coolant, a pump (1200, 2200, 3200) for circulating the coolant, and a coolant discharged from the storage tank. A tank discharge pipe (1150, 2150, 3150) that guides the coolant discharged from the pump, a pump discharge pipe (1250, 2250, 3250) that guides the coolant discharged from the pump, and a coolant that is coupled to the pump discharge pipe and flows in from the pump discharge pipe. Channel valves (1300, 2300, 3300) that control the flow direction of the coolant, and a channel branch pipe (1350) that extends from one outlet end of the channel valve to the coolant inlet of the evaporator (500, 600, 700) and guides the coolant to the evaporator. 2350, 3350) and a channel combination pipe (1360, 2360, 3360) extending straight from the other outlet end of the channel valve to a point of the introduction pipe (1400, 2400, 3400).

The channel units 1000, 2000, and 3000 may be provided in multiple numbers, and the plurality of channel units, that is, a plurality of channel cycles, may be connected in parallel with the secondary low temperature cycle (SC).

In detail, any one of the plurality of evaporators (500, 600, and 700) connected in series may be configured to exchange heat with the coolant circulating in one of the plurality of channel parts.

The channel valves 1300, 2300, and 3300 may be provided as three-way valves.

The storage tanks 1100, 2100, and 3100 may include heaters capable of heating the cooler.

Meanwhile, the channel valves (1300, 2300, 3300) and the heater operate to control the coolant to a specific temperature required within the range of the lowest and highest operating temperatures set for each channel unit (1000, 2000, 3000). can do.

The coolant flowing into each of the evaporators (500, 600, and 700) through the channel branch pipes (1350, 2350, and 3350) is a secondary mixed refrigerant that passes through the second expansion valve (400) and serially passes through the evaporators (500, 600, and 700). It can be cooled by dissipating heat.

And the coolant cooled through heat exchange with the secondary mixed refrigerant can be discharged to the introduction pipes (1400, 2400, and 3400) and returned to each channel portion (1000, 2000, and 3000).

The channel portions 1000, 2000, and 3000 include a first channel portion 1000 through which a coolant capable of heat exchange with the first evaporator 500 circulates, and a coolant through which heat exchange with the second evaporator 600 circulates. It may include a second channel unit 2000 and a third channel unit 3000 through which coolant capable of heat exchange with the third evaporator 700 circulates.

Therefore, the channel cycle in which the coolant introduced and recovered from the first channel unit 1000 circulates coolant from the first storage tank 1100 and the first evaporator 500 to the first channel unit 1000. The guiding first introduction pipe 1400, the first return pipe, the first tank discharge pipe 1150, the first pump 1200, the first pump discharge pipe 1250, the first channel valve 1300, and the first evaporator. (500) may include a first channel branch pipe 1350 and a first channel combination pipe 1360 that guide the coolant.

For example, the minimum required operating temperature of the first channel unit 1000 may be set to -90 degrees (°C), and the maximum temperature may be set to 50 degrees (°C). In addition, the specific temperature required for each situation in the first channel unit 1000 can be adjusted through the heater provided in the first storage tank 1100 and/or the opening degree control of the first channel valve 1300.

That is, through control of the opening degree of the first channel valve 1300, the coolant circulating in the first channel part 1000 branches into the first channel branch pipe 1350 and the first channel combination pipe 1360, or It can be made to flow selectively.

The coolant flowing through the first channel branch pipe 1350 may exchange heat with the secondary mixed refrigerant of the first evaporator 500. Here, in order to respond to the operating temperature requirement of the first channel unit 1000, the temperature of the secondary mixed refrigerant flowing into the refrigerant inlet of the first evaporator 500 can be set to -100 degrees (°C). there is. At this time, the temperature of the secondary mixed refrigerant before passing through the second expansion valve 400 may be set to -60 degrees (°C).

In addition, the temperature of the secondary mixed refrigerant discharged from the refrigerant outlet of the first evaporator 500 can be set to -75 degrees (°C). Here, the outlet temperature of the first evaporator 500 is the second mixed refrigerant. It can be adjusted in consideration of the required operating temperature of the channel unit 2000.

Likewise, the channel cycle in which the coolant introduced and recovered from the second channel unit 2000 circulates coolant from the second storage tank 2100 and the second evaporator 600 to the second channel unit 2000. A guiding second inlet pipe (2400), a second return pipe, a second tank discharge pipe (2150), a second pump (2200), a second pump discharge pipe (2250), a second channel valve (2300), and the second evaporator. (600) may include a second channel branch pipe 2350 and a second channel combination pipe 2360 that guide the coolant.

For example, the minimum required operating temperature of the second channel unit 2000 may be set to -60 degrees (°C), and the maximum temperature may be set to 50 degrees (°C). In addition, the specific temperature required for each situation in the second channel unit 2000 can be adjusted through the heater provided in the second storage tank 2100 and/or the opening degree control of the second channel valve 2300.

The coolant flowing into the second channel branch pipe 2350 may exchange heat with the secondary mixed refrigerant of the second evaporator 600. Here, in order to respond to the required operating temperature of the second channel unit 2000, the temperature of the secondary mixed refrigerant flowing into the refrigerant inlet of the second evaporator 600 is the refrigerant outlet temperature of the first evaporator 500. In the same way, it can be formed at -75 degrees (°C), and the temperature of the secondary mixed refrigerant discharged from the refrigerant outlet of the second evaporator 600 can be formed at -50 degrees (°C). Here, the outlet temperature of the second evaporator 600 can be adjusted in consideration of the required operating temperature of the third channel unit 3000.

Likewise, the channel cycle in which the coolant introduced and recovered from the third channel unit 3000 circulates coolant from the third storage tank 3100 and the third evaporator 700 to the third channel unit 3000. A third guiding pipe (3400), a third return pipe, a third tank discharge pipe (3150), a third pump (3200), a third pump discharge pipe (3250), a third channel valve (3300), and the third evaporator. (500) may include a third channel branch pipe 3350 and a third channel combination pipe 3360 that guide the coolant.

For example, the minimum required operating temperature of the third channel unit 3000 may be set to -40 degrees (°C), and the maximum temperature may be set to 50 degrees (°C). In addition, the specific temperature required for each situation in the third channel unit 3000 can be adjusted through the heater provided in the third storage tank 3100 and/or the opening degree control of the third channel valve 3300.

The coolant flowing through the third channel branch pipe 3350 may exchange heat with the secondary mixed refrigerant of the third evaporator 700. Here, in order to respond to the required operating temperature of the third channel unit 3000, the temperature of the secondary mixed refrigerant flowing into the refrigerant inlet of the third evaporator 700 is the refrigerant outlet temperature of the second evaporator 600. In the same way, it can be set to -50 degrees (°C), and the temperature of the secondary mixed refrigerant discharged from the refrigerant outlet of the third evaporator 700 can be set to -25 degrees (°C).

At this time, the temperature of the secondary mixed refrigerant that is overheated and sucked into the second compressor 100 may be set to -25 degrees (°C).

Meanwhile, coolant circulated through each of the plurality of channel units 1000, 2000, and 3000 may include HFE 7200. The boiling point of HFE 7200 is about 76 degrees Celsius (°C). Accordingly, the maximum required temperature in the above-described first to third channel parts (1000, 2000, and 3000) can be limited to 50 degrees Celsius (°C), and can be explained based on the limited maximum required temperature.

Figure 3 is a diagram showing a P-h diagram for the second low temperature cycle (SC) of the cooling system according to an embodiment of the present invention.

Referring to FIGS. 2 and 3, in the first low temperature cycle (FC), heat is exchanged with the first mixed refrigerant through the bridge heat exchanger 300, and then sequentially passes through the first to third evaporators (500, 600, and 700). 2 The cycle of the secondary mixed refrigerant recovered from the compressor 100 can be confirmed.

In detail, the secondary mixed refrigerant compressed (S100) in the second compressor (100) is primarily condensed (S200) in the second condenser (200) and exchanges heat with the primary mixed refrigerant in the bridge heat exchanger (300). By doing so, it can be secondaryly condensed to a cryogenic state (S300). For example, the secondary mixed refrigerant that has passed through the bridge heat exchanger 300 may be condensed to about -60 to -80 degrees.

And the secondary mixed refrigerant expanded by the second expansion valve 400 can be cooled to about -100 degrees to form a cryogenic temperature.

And the secondary mixed refrigerant expanded to the cryogenic temperature may be evaporated while sequentially passing through the first to third evaporators (500, 600, and 700) and recovered to the second compressor (100).

Here, the coolant of the first channel part is cooled through heat exchange (S500) with the first channel part 1000 in the first evaporator 500, and the coolant having a higher operating temperature requirement than the first channel part 1000 is cooled. A third channel unit that exchanges heat with the second channel unit (2000) through the second evaporator (600) (S600) to cool the coolant of the second channel unit, and has a higher required operating temperature than the second channel unit (2000). The coolant in the third channel portion can be cooled by heat exchange (S700) with the third evaporator 700 (3000).

10: first compressor 20: first condenser
30: Recuperator 40: First expansion valve
100: second compressor 200: second condenser
300: Bridge heat exchanger 400: Second expansion valve
500: first evaporator 600: second evaporator
700: Third evaporator

Claims (15)

A first low-temperature cycle in which the first mixed refrigerant circulates;
A second low-temperature cycle in which a second mixed refrigerant circulates;
a bridge heat exchanger configured to exchange heat between the first mixed refrigerant of the first low-temperature cycle and the second mixed refrigerant of the second low-temperature cycle; and
connected in parallel to the secondary low temperature cycle, comprising a plurality of channel sections each having a different minimum temperature required for operation;
The secondary low-temperature cycle includes a plurality of evaporators connected in series through which the secondary mixed refrigerant sequentially passes,
Each of the plurality of channel units is connected one to one to exchange heat with one of the plurality of evaporators,
The secondary mixed refrigerant and the coolant circulating through each of the plurality of channel parts exchange heat in the one-to-one connected evaporator,
A cryogenic cooling system in which the first evaporator among the series-connected evaporators is connected to the channel portion having the lowest minimum temperature among the plurality of channel portions.
According to claim 1,
A cryogenic cooling system in which the last evaporator among the series-connected evaporators is connected to enable heat exchange with the channel portion having the highest minimum temperature among the plurality of channel portions.
According to claim 2,
The plurality of channel units,
A cryogenic cooling system connected one-to-one to the plurality of evaporators so that the evaporation temperature of the secondary mixed refrigerant, which changes as it sequentially passes through the plurality of evaporators, matches the minimum temperature required for operation of each of the plurality of channel parts.
According to claim 3,
The bridge heat exchanger is a cryogenic cooling system in which at least a portion of the first mixed refrigerant is evaporated and at least a portion of the second mixed refrigerant is condensed through heat exchange.
According to claim 3,
The first low temperature cycle is,
a first compressor through which the first mixed refrigerant circulates;
a first condenser in which the first mixed refrigerant discharged from the first compressor is condensed;
a recuperator configured to exchange heat between the first mixed refrigerant discharged from the first condenser and the first mixed refrigerant discharged from the bridge heat exchanger; and
A cryogenic cooling system comprising a first expansion valve installed between the bridge heat exchanger and the recuperator to expand the refrigerant discharged from the recuperator and introduced into the bridge heat exchanger.
According to claim 5,
The primary mixed refrigerant flowing into the first condenser exchanges heat through the primary cooling pipe through which cooling water or room temperature refrigerant circulates,
When room temperature refrigerant circulates in the primary cooling pipe, the primary cooling pipe is an evaporation area of the refrigeration cycle of the room temperature refrigerant.
According to claim 5,
The second low temperature cycle is,
a second compressor through which the second mixed refrigerant circulates;
a second condenser in which the refrigerant discharged from the second compressor is condensed; and
A cryogenic cooling system further comprising a second expansion valve that expands the refrigerant discharged from the bridge heat exchanger and is installed between the first evaporator of the plurality of series-connected evaporators and the bridge heat exchanger to expand the secondary mixed refrigerant.
According to claim 7,
The bridge heat exchanger,
A cryogenic cooling system configured to exchange heat between the secondary mixed refrigerant that passed through the second condenser and the primary mixed refrigerant that passed through the first expansion valve.
According to claim 7,
The secondary mixed refrigerant flowing into the second condenser is a cryogenic cooling system in which heat is exchanged through cooling pipes through which coolant, room temperature refrigerant, or a mixed refrigerant with a relatively higher boiling point than the secondary mixed refrigerant circulates.
According to claim 7,
The plurality of evaporators include a first evaporator that introduces the secondary mixed refrigerant that has passed through the second expansion valve and exchanges heat with the coolant of one channel portion;
a second evaporator connected in series with the first evaporator and receiving the secondary mixed refrigerant discharged from the first evaporator to exchange heat with the coolant of the other channel; and
A cryogenic cooling system comprising a third evaporator connected in series with the second evaporator and receiving the secondary mixed refrigerant discharged from the second evaporator to exchange heat with the coolant of another channel.
According to claim 10,
The second low temperature cycle is,
a first connection pipe extending from the first evaporator to the second evaporator to guide sequential evaporation of the secondary mixed refrigerant; and
A cryogenic cooling system further comprising a second connection pipe extending from the second evaporator to the third evaporator to guide sequential evaporation of the secondary mixed refrigerant.
According to claim 10,
The plurality of channel units,
a first channel portion that exchanges heat with the first evaporator;
a second channel unit having a higher minimum temperature than the first channel unit and exchanging heat with the second evaporator; and
A cryogenic cooling system comprising a third channel unit having a higher minimum temperature than the second channel unit and exchanging heat with the third evaporator.
According to claim 12,
A cryogenic cooling system in which the first to third channel units are set to the same maximum temperature required for operation.
According to claim 1,
The plurality of channel units, respectively,
an inlet pipe extending from the coolant outlet of the evaporator to the inlet of the channel portion to introduce the coolant that has passed through the evaporator;
a storage tank in which the coolant is stored;
a recovery pipe extending from the outlet of the channel unit to the storage tank to recover coolant;
a pump for circulating the coolant;
A channel valve that controls the flow direction of coolant discharged from the pump;
a channel branch pipe extending from one outlet end of the channel valve to the coolant inlet of the evaporator; and
A cryogenic cooling system comprising a channel combination pipe extending straight from the other outlet end of the channel valve to a point of the introduction pipe.
According to claim 1,
The first mixed refrigerant and the second mixed refrigerant,
At least one primary low-temperature refrigerant among R116, R23, and R508B; and
A cryogenic cooling system comprising at least one secondary low-temperature refrigerant among R1150, R14, and R50.

Images