Condensation pump type dilution refrigerator with booster pump

Abstract

The condensation pump type dilution refrigerating machine with the booster pump comprises the pre-cooling module and the dilution module, the pre-cooling module provides the required pre-cooling temperature for the dilution module, the dilution module uses the booster pump working at 1K, 3He circulation is achieved through cooperation of the booster pump and the condensation pump, no room-temperature circulation system is arranged, and therefore the dilution effect is good. And the defects of high heat loss and high compression power consumption in a room temperature circulation mode are overcome. Meanwhile, due to the fact that the booster pump is used, the system can obtain larger circulating flow so as to achieve larger cooling capacity, and the defect that a condensation pump type dilution refrigerator obtains large refrigerating power is overcome.

Description

Technical Field

[0001] This application relates to the field of cryogenic refrigeration, and specifically to a condensing pump type dilution refrigerator with a booster pump. Background Art

[0002] Cryogenic refrigeration technology refers to the refrigeration technology that can obtain a temperature below 1K and provide a certain amount of cooling capacity. In recent years, with the rapid development of science and technology, the demand for cryogenic temperatures has been increasing continuously, especially in fields such as scientific exploration and high-end instruments. The main technologies for obtaining cryogenic temperatures include adsorption refrigeration (AR), adiabatic demagnetization refrigeration (ADR), and dilution refrigeration (DR).

[0003] Dilution refrigeration is a refrigeration method that utilizes 3 He and 3 He- 4 the properties of the He-He mixture at extremely low temperatures to obtain extremely low temperatures. In an extremely low temperature environment, 3 He- 4 the He-He mixture will undergo phase separation and stratify under the action of gravity. 3 The He-rich phase is in the upper layer and the dilute phase is in the lower layer. 3 When He atoms pass through the phase interface from the rich phase into 3 the He dilute phase at extremely low temperatures, an endothermic phenomenon occurs to achieve refrigeration.

[0004] There are various classification methods for dilution refrigerators. According to the different circulation pumps, dilution refrigerators can be divided into conventional dilution refrigerators that utilize an external pump circulation and cryogenic circulation dilution refrigerators that utilize a cryogenic adsorption pump or a condensing pump circulation.

[0005] The conventional dilution refrigerator leads the 3 He gas (~0.7K) evaporated from the distillation chamber to room temperature for compression. After compression, the 3 He gas needs to be cooled from room temperature to the condensation temperature (~3K) again. This kind of cycle is essentially inefficient.

[0006] For the condensing pump type dilution refrigerator, it belongs to a cryogenic cycle. Compared with the conventional dilution refrigerator, its cycle efficiency is higher. However, the performance of the condensing pump is limited by its volume, which thus limits the flow rate of the condensing pump. Therefore, generally, the cooling power of the condensing pump type dilution refrigerator is relatively low. Its maximum flow rate is about 100 μmol / s, which is much smaller than 10 mmol / s of the conventional DR.

[0007] In summary, the conventional dilution refrigerator can obtain a large refrigeration power, but its structure is complex, and because it adopts a room temperature cycle, its cycle efficiency is relatively low. The condensing pump type dilution refrigerator has no room temperature cycle and has a higher cycle efficiency, but due to the volume limitation of the condensing pump, its refrigeration power is small. Summary of the Invention

[0008] In view of this, it is necessary to provide a condensing pump type dilution refrigerator with a simple structure, high efficiency and large refrigeration power for the technical problem of the existing condensing pump type dilution refrigerator having a small refrigeration power.

[0009] To solve the above problems, the present application adopts the following technical solutions:

[0010] A condensing pump type dilution refrigerator with a booster pump provided by the present application includes a precooling module and a dilution module. The precooling module is used to provide a precooling temperature below 1K. The dilution module includes a mixing chamber (101), a heat exchanger group (100), a distillation chamber (104), a low-pressure side gas pipeline (105), a regenerator group (200), a low-pressure buffer tank (108), a first check valve (109), a booster pump (110), a second check valve (111), a high-pressure buffer tank (112), a precooling heat exchanger (113), a high-pressure side gas pipeline (114) and a condensing pump (115). The mixing chamber (101) contains 3 He- 4 He mixture. The 3 He- 4 He mixture can achieve phase separation in the mixing chamber (101), with the concentrated phase on top and the dilute phase at the bottom. 3 He atoms enter the dilute phase from the concentrated phase to produce refrigeration. The condensing pump (115) has good heat exchange with the 3 He- 4 He mixture liquid in the distillation chamber (104); where:

[0011] [[ID=...]] The 3 He- 4 He mixture liquid in the mixing chamber (101) flows into the distillation chamber (104) after heat exchange treatment by the heat exchanger group (100). The distiller (104) heats the 3 He- 4 He mixture liquid to achieve 3 He liquid gasification. The formed [[ID=3...]] 3 He gas passes through the low-pressure side gas pipeline (105) and enters the low-pressure buffer tank (108) through the regenerator group (200). Under the action of the booster pump (110), the 3 He gas in the low-pressure buffer tank (108) enters the high-pressure buffer tank (112) through the first check valve (109) and the second check valve (111). The 3The He gas passes through the regenerator group (200) and then enters the distillation chamber (104) through the high-pressure side gas pipeline (114). After being condensed and liquefied in the condensation pump (115), it is precooled by the heat exchanger group (100) and enters the mixing chamber (101) for dilution refrigeration, and then enters the distillation chamber (104) through the heat exchanger group (100) to continue circulating;

[0012] The precooling module can precool the He gas passing through the regenerator group (200). 3 He gas is precooled.

[0013] In some embodiments, the heat exchanger group (100) includes a primary heat exchanger (103) and a secondary heat exchanger (102) arranged in series. The distiller (104) heats the He-He mixture liquid to vaporize the He liquid, and the formed He gas passes through the low-pressure side gas pipeline (105) and sequentially passes through the secondary heat exchanger (102) and the primary heat exchanger (103); the He gas condensed and liquefied in the condensation pump (115) is precooled by the primary heat exchanger (103) and the secondary heat exchanger (102) and enters the mixing chamber (101) for dilution refrigeration. 3 He- 4 He mixture liquid is heated to achieve 3 He liquid gasification, and the formed 3 He gas passes through the low-pressure side gas pipeline (105) and sequentially passes through the secondary heat exchanger (102) and the primary heat exchanger (103); after being condensed and liquefied in the condensation pump (115), the 3 He gas is precooled by the primary heat exchanger (103) and the secondary heat exchanger (102) and enters the mixing chamber (101) for dilution refrigeration.

[0014] In some embodiments, the primary heat exchanger (104) adopts a tube-in-tube structure, and the tube-in-tube structure is composed of two coaxial capillary tubes wound into a spiral shape.

[0015] In some embodiments, the secondary heat exchanger (105) is a stepped heat exchanger, and the stepped heat exchanger is a multi-stage series connection.

[0016] In some embodiments, the regenerator group (200) includes a secondary regenerator (106) and a primary regenerator (107) arranged in series. The He gas passes through the low-pressure side gas pipeline (105) and sequentially passes through the secondary regenerator (106) and the primary regenerator (107) and enters the low-pressure buffer tank (108); the He gas in the high-pressure buffer tank (112) sequentially passes through the primary regenerator (107) and the secondary regenerator (106) and then enters the condensation pump (115) through the high-pressure side gas pipeline (114). 3 He gas passes through the low-pressure side gas pipeline (105) and sequentially passes through the secondary regenerator (106) and the primary regenerator (107) and enters the low-pressure buffer tank (108); the 3 He gas in the high-pressure buffer tank (112) sequentially passes through the primary regenerator (107) and the secondary regenerator (106) and then enters the condensation pump (115) through the high-pressure side gas pipeline (114).

[0017] In some of these embodiments, the precooling module includes a liquid helium bath (116), an impedance (117), a high-pressure gas pipeline (118), and a low-pressure gas pipeline (119). The liquid helium bath (116) is connected to the high-pressure gas pipeline (118) and the low-pressure gas pipeline (119). The impedance (117) is provided on the high-pressure gas pipeline (118). The 4 evaporated 4 He gas in the liquid helium bath (116) passes through the low-pressure gas pipeline (119) to a circulation pump. After circulation, the 4 He gas is transported by the high-pressure gas pipeline (118), and after being precooled by a precooling refrigerator, it passes through the impedance (117) to generate throttling refrigeration and liquefies into 4 He liquid to supplement the 4 He liquid in the liquid helium bath (116).

[0018] In some of these embodiments, it further includes a precooling heat exchanger (113) disposed in the liquid helium bath (116). The 3 He gas in the high-pressure buffer tank (112) enters the secondary regenerator (106) through the primary regenerator (107) and then through the precooling heat exchanger (113).

[0019] The present application adopts the above technical solutions, and the beneficial effects are as follows:

[0020] The condensing pump type dilution refrigerator with a booster pump provided by the present application includes a precooling module and a dilution module. The precooling module provides a precooling temperature for the dilution module. The dilution module uses a booster pump operating at 1K, and cooperates with the condensing pump to achieve 3 the circulation of He, cancels the room temperature circulation system, and overcomes the defects of large heat loss and large compression power consumption existing in the room temperature circulation mode. At the same time, since the booster pump can achieve a greater cooling capacity, it also compensates for the deficiency of the condensing pump type dilution refrigerator when obtaining a greater refrigeration power. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] [[ID=3)) Figure 1 It is a schematic structural diagram of the condensing pump type dilution refrigerator with a booster pump provided by this embodiment.

[0023] 101 - Mixing chamber, 100 - Heat exchanger group, 102 - Secondary heat exchanger, 103 - Primary heat exchanger, 104 - Distillation chamber, 105 - Low - pressure side gas pipeline, 200 - Regenerator group, 106 - Secondary regenerator, 107 - Primary regenerator, 108 - Low - pressure buffer tank, 109 - Check valve, 110 - Booster pump, 111 - Check valve, 112 - High - pressure buffer tank, 113 - Pre - cooling heat exchanger, 114 - High - pressure side gas pipeline, 115 - Condensation pump, 116 - Liquid helium pool, 117 - Impedance, 118 - High - pressure gas pipeline, 119 - Low - pressure gas pipeline. Detailed implementation manners

[0024] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as a limitation to the present application.

[0025] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0026] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "plurality" is two or more unless otherwise specifically defined.

[0027] For the purpose of making the objectives, technical solutions and advantages of the present application more clearly understood, the following takes the multi - functional detection of atherosclerosis in blood vessels as an example, and further elaborates on the present application in combination with the accompanying drawings and embodiments.

[0028] Please refer to Figure 1The structural diagram of a condensing pump type dilution refrigerator with a booster pump provided in an embodiment of the present application includes: a pre-cooling module and a dilution module, wherein the pre-cooling module is used to provide a pre-cooling temperature below 1K, the dilution module includes a mixing chamber (101), a heat exchanger group (100), a distillation chamber (104), a low-pressure side gas pipeline (105), a regenerator group (200), a low-pressure buffer tank (108), a first one-way valve (109), a booster pump (110), a second one-way valve (111), a high-pressure buffer tank (112), a pre-cooling heat exchanger (113), a high-pressure side gas pipeline (114) and a condensing pump (115), and the mixing chamber (106) accommodates 3 He- 4 He mixture, the 3 He- 4 The He mixture can achieve phase separation in the mixing chamber (101), with the dense phase on top and the dilute phase on the bottom. 3 He atoms enter the dilute phase from the concentrated phase to generate refrigeration, and the condensation pump (115) is located in the distillation chamber (104). The specific implementation of each component and its connection relationship are described in detail below.

[0029] The pre-cooling module mainly provides a temperature below 1K for the dilution circulation system. Generally, a 4K pre-cooling refrigerator (not shown in the figure) is first used to provide a temperature of 4K. A mechanical refrigerator or a superfluid helium refrigerator can be used.

[0030] In this embodiment, the pre-cooling module includes a liquid helium pool (116), an impedance (117), a high-pressure gas pipeline (118) and a low-pressure gas pipeline (119); the liquid helium pool (116) is connected to the high-pressure gas pipeline (118) and the low-pressure gas pipeline (119); and the impedance (117) is provided on the high-pressure gas pipeline (118).

[0031] Specifically, the liquid helium pool (116) 4 He liquid evaporation can provide a temperature of 0.8K, and the evaporated 4 He gas is passed through the low pressure gas pipeline (119) to the circulation pump (cryogenic adsorption pump, room temperature mechanical pump). 4 He is transported by a high-pressure gas pipeline (118), pre-cooled to 4K by a 4K pre-cooling refrigerator, and then throttled by an impedance (117), where the temperature is further reduced and liquefied to replenish the liquid helium pool (116). The actual method of providing pre-cooling includes but is not limited to the methods mentioned above, which will not be described in detail here.

[0032] The mixing chamber (101) is used to accommodate 3 He- 4 He mixture, 3 He- 4The He mixture undergoes phase separation within the mixing chamber (101), with the dense phase on top and the dilute phase at the bottom. 3 He atoms pass from the dense phase through the phase interface into the dilute phase, generating refrigeration, and transferring the cold quantity to the outside through the mixing chamber. The mixing chamber 101 serves as a window for a condensing pump - type dilution refrigerator with a booster pump to transfer extremely low - temperature cold quantity to the outside, and can provide continuous refrigeration for the heat load.

[0033] The heat exchanger group (100) functions for heat exchange, and can exchange heat between the He - He mixture liquid flowing from the mixing chamber (101) into the distillation chamber (104) and the He liquid flowing from the condensing pump (115) into the mixing chamber (101), that is, it raises the temperature of the He - He mixture liquid flowing from the mixing chamber (101) into the distiller (104) and lowers the temperature of the He liquid flowing from the condensing pump (115) into the mixing chamber (101), playing a role in further precooling the He liquid flowing from the condensing pump (115) into the mixing chamber. 3 He - 4 He mixture liquid and the He liquid flowing from the condensing pump (115) into the mixing chamber (101). 3 He - 3 He mixture liquid temperature rise and the temperature of the He liquid flowing from the condensing pump (115) into the mixing chamber (101) decrease, playing a role in further precooling the He liquid flowing from the condensing pump (115) into the mixing chamber. 4 He liquid further precooling. 3 He liquid flowing from the condensing pump (115) into the mixing chamber 3 He liquid further precooling.

[0034] In this embodiment, the primary heat exchanger (104) adopts a tube - in - tube structure, which consists of two coaxial capillary tubes wound in a spiral shape; the secondary heat exchanger (105) is a stepped heat exchanger, which is a multi - stage series connection. Two channels are drilled in the copper block, and a certain amount of sintered metal powder is added to each channel to increase the heat exchange area and reduce the Kapitza thermal resistance.

[0035] In the distillation chamber (104), the 3 He - 4 He mixture is heated, and the heat comes from the heat released at the condensing pump (115). At the same time, in order to facilitate the regulation of the heating amount, a heater is also arranged in the distillation chamber (104). Because the saturation vapor pressure of He is significantly higher than that of He, the evaporated gas is almost pure He, thus realizing the gasification of He liquid. In order to maintain a certain circulation flow rate, generally, the temperature of the distillation chamber 104 is maintained at 600 - 700 mK, and the pressure is the saturation vapor pressure (8 - 12 Pa) of the He - He mixture at this temperature. 3 He's saturation vapor pressure is significantly higher than 4 He, and the evaporated gas is almost pure 3 He, thus realizing 3 He liquid gasification. To maintain a certain circulation flow rate, generally, the temperature of the distillation chamber 104 is maintained at 600 - 700 mK, and the pressure is the saturation vapor pressure (8 - 12 Pa) of the 3 He - 4 He mixture at this temperature.

[0036] The regenerator group (200) has a precooling effect. It includes a secondary regenerator (106) and a primary regenerator (107) arranged in series.

[0037] In this embodiment, the compressed high-pressure gas is pre-cooled by the secondary regenerator (106), the primary regenerator (107) and the pre-cooling heat exchanger (113), and then condensed and liquefied in the condensation pump (115). The condensation pump (115) has a large heat exchange area and requires a cold source that can provide cold capacity.

[0038] In this embodiment, the cooling source for the condensate pump (115) is the distillation chamber (104), and the cooling energy comes from the latent heat of vaporization of the dilute phase mixture during phase change. The temperature of the dilute phase entering the distillation chamber (104) after passing through the primary heat exchanger (103) is about 200mK, and then the temperature of the mixture rises to 600mK to 700mK. 3 The saturated vapor pressure of He is relatively small and will evaporate first. This part of the cooling capacity is used as pre-cooling for the condenser pump. After calculation, the distillation chamber (104) 3 The heat absorption of He evaporation and the condensation pump (115) 3 The heat released by He liquefaction is basically balanced, and the system can continue to operate under the condition of ideal heat exchange effect. 3 The He gas pressure is about 10Pa. Its temperature rises through the dilute gas pipeline (105) and the secondary regenerator (106) and the primary regenerator (107). The resistance coefficient of the low-pressure side gas pipeline and the two-stage regenerator should be as small as possible to reduce 3 He gas pressure drop.

[0039] Booster pump (110) is to achieve 3 One of the key components of the He cycle, the booster pump in this example uses a piston compressor, which is actually 3 The He gas compression methods include but are not limited to the above mentioned methods, such as scroll compressors or compressors using superconducting coils to drive motors, etc., which will not be described in detail here. The intake valve and exhaust valve are important components of the gas circulation system and need to have the function of rapid opening and closing. 3 The booster pump (110) cooperates with the one-way valves (109) and (111). When the one-way valve (109) is opened during the suction, the low-pressure buffer tank 108 is filled with 3 He gas is sucked into the chamber. During compression, both one-way valves 109 and 111 are closed, and the gas pressure increases. During exhaust, the one-way valve (111) opens, and the compressed 3 The He gas enters the high-pressure buffer tank (112). Since the low-pressure buffer tank (108) and the high-pressure buffer tank (112) have large volumes, they can act as a pressure stabilizer, so that the pressure fluctuation caused by each suction and exhaust of the booster pump (110) is sufficiently small, thereby improving system stability.

[0040] The working process of the condenser pump type dilution refrigerator with a booster pump provided in the above embodiment of the present application is as follows:

[0041] The mixing chamber (101) 3 He- 4 The He mixture liquid flows into the distillation chamber (104) after heat exchange treatment in the heat exchanger group (100). The distillation chamber (104) 3 He- 4 He mixture liquid is heated to achieve 3 He liquid vaporizes, forming 3 The He gas passes through the low-pressure side gas pipeline (105) and the regenerator group (200) into the low-pressure buffer tank (108). Under the action of the booster pump (110), the He gas in the low-pressure buffer tank (108) 3 The He gas then passes through the first one-way valve (109) and the second one-way valve (111) and enters the high-pressure buffer tank (112). 3 The He gas passes through the regenerator group (200) and then enters the distillation chamber (104) through the high-pressure side gas pipeline (114). After being condensed and liquefied in the condensation pump (115), it is pre-cooled through the heat exchanger group (100) and enters the mixing chamber (101) for dilution refrigeration. It then enters the distillation chamber (104) through the heat exchanger group (100) to continue circulation.

[0042] Specifically, 3 The He gas is pressurized to 100 Pa (slightly greater than the saturated vapor pressure corresponding to the distillation chamber temperature) by a booster pump (110), and precooled to about 0.8 K by a liquid helium pool (116) and a precooling heat exchanger (113); 3 He passes through the secondary regenerator (106) and exchanges heat with the low-pressure gas at a lower temperature, and the pressure and temperature are reduced. At this time, the gas temperature is close to the temperature T of the distillation chamber (104). s , the pressure is slightly higher than T s The corresponding saturated vapor pressure. 3 Driven by pressure, He then flows into the dilute phase pipelines of the primary heat exchanger (103) and the secondary heat exchanger (102). 3 He flows out of the primary heat exchanger (103) and flows into the distillation chamber (104). In the dilute phase mixture in the distillation chamber (104), the temperature rises due to heat absorption. 3 He evaporates from the mixture and the gas pressure is 8-12 Pa.

[0043] The condenser pump type dilution refrigerator with a booster pump provided in this embodiment is 3He circulates at low temperature, the compressor works at 1K, isentropic compression, the efficiency is 30%, and a circulation flow of 1.5mmol / s is provided. The power consumption of the compressor is only 0.34W, which can effectively reduce the compression power consumption compared to the room temperature cycle. Since the gas completes the cycle at low temperature, the gas temperature is low, and the gas pressure after pressurization is 100~200Pa, it can be condensed by a condensation pump with an operating temperature of 600~700mK. It does not need to use impedance to liquefy through throttling refrigeration. Compared with the existing condensation pump type dilution refrigerator, the condensation pump must be lower than the distillation chamber temperature to work. The requirements for the pre-cooling refrigerator are reduced, and the system structure is simplified. According to estimates, the heat released by the condensation of the high-pressure gas is basically equal to the latent heat of phase change of the evaporation of the liquid in the distillation chamber. Considering the ideal heat exchange effect, when the cycle is operating normally, the distillation chamber does not need to be heated by a heater, and the operation is more convenient. By circulating with a booster pump in conjunction with a condensation pump, a larger circulation flow can be achieved and a greater cooling power can be obtained. In summary, by using a booster pump working at a low temperature to carry out 3 The performance of He cycle and condensate pump type dilution refrigerator will be substantially improved.

[0044] It can be understood that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. A condenser pump type dilution refrigerator with a booster pump, characterized in that: include: A precooling module and a dilution module, wherein the precooling module is used to provide a precooling temperature below 1K, and the dilution module comprises a mixing chamber (101), a heat exchanger group (100), a distillation chamber (104), a low-pressure side gas pipeline (105), a regenerator group (200), a low-pressure buffer tank (108), a first one-way valve (109), a booster pump (110), a second one-way valve (111), a high-pressure buffer tank (112), a precooling heat exchanger (113), a high-pressure side gas pipeline (114) and a condensation pump (115), wherein the mixing chamber (101) accommodates 3 He- 4 He mixture, the 3 He- 4 The He mixture can achieve phase separation in the mixing chamber (101), with the dense phase on top and the dilute phase on the bottom. 3 He atoms enter the dilute phase from the dense phase to generate refrigeration, and the condensation pump (115) and the distillation chamber (104) are connected. 3 He- 4 He mixture liquid has good heat transfer; The mixing chamber (101) 3 He- 4 The He mixture liquid flows into the distillation chamber (104) after heat exchange treatment in the heat exchanger group (100). The distillation chamber (104) 3 He- 4 He mixture liquid is heated to achieve 3 He liquid vaporizes, forming 3 The He gas passes through the low-pressure side gas pipeline (105) and the regenerator group (200) into the low-pressure buffer tank (108). Under the action of the booster pump (110), the He gas in the low-pressure buffer tank (108) 3 The He gas then passes through the first one-way valve (109) and the second one-way valve (111) and enters the high-pressure buffer tank (112). 3 After passing through the regenerator group (200), the He gas enters the condensation pump (115) through the high-pressure side gas pipeline (114), and after being condensed and liquefied in the condensation pump (115), it is pre-cooled through the heat exchanger group (100) and enters the mixing chamber (101) for dilution refrigeration, and then enters the distillation chamber (104) through the heat exchanger group (100) to continue circulation; The pre-cooling module can 3 He gas is pre-cooled.

2. The condenser pump type dilution refrigerator with a booster pump according to claim 1, wherein: The heat exchanger group (100) includes a primary heat exchanger (103) and a secondary heat exchanger (102) arranged in series, and the distiller (104) 3 He- 4 He mixture liquid is heated to achieve 3 He liquid vaporizes, forming 3 The He gas passes through the low-pressure side gas pipeline (105) and sequentially passes through the secondary heat exchanger (102) and the primary heat exchanger (103); the He gas is condensed and liquefied in the condensation pump (115). 3 The He gas is pre-cooled through the primary heat exchanger (103) and the secondary heat exchanger (102) and enters the mixing chamber (101) for dilution refrigeration.

3. The condenser pump type dilution refrigerator with a booster pump according to claim 2, wherein: The primary heat exchanger (104) adopts a tube-in-tube structure, which is composed of two coaxial capillaries wound into a spiral shape.

4. The condenser pump type dilution refrigerator with a booster pump according to claim 3, wherein: The secondary heat exchanger (105) is a stepped heat exchanger, and the stepped heat exchanger is multi-stage series-connected.

5. The condenser pump type dilution refrigerator with a booster pump according to claim 1, wherein: The regenerator group (200) includes a secondary regenerator (106) and a primary regenerator (107) arranged in series. 3 The He gas passes through the low-pressure side gas pipeline (105) and sequentially enters the secondary regenerator (106) and the primary regenerator (107) into the low-pressure buffer tank (108); the high-pressure buffer tank (112) 3 The He gas passes through the first-stage regenerator (107) and the second-stage regenerator (106) in sequence and then enters the condensation pump (115) through the high-pressure side gas pipeline (114).

6. The condenser pump type dilution refrigerator with a booster pump according to claim 5, wherein: The pre-cooling module comprises a liquid helium pool (116), an impedance (117), a high-pressure gas pipeline (118) and a low-pressure gas pipeline (119); the liquid helium pool (116) is connected to the high-pressure gas pipeline (118) and the low-pressure gas pipeline (119); the impedance (117) is provided on the high-pressure gas pipeline (118); 4 He liquid evaporates 4 He gas is passed through the low-pressure gas pipeline (119) to the circulation pump, and the circulating 4 He gas is transported by the high-pressure gas pipeline (118), and then pre-cooled by the pre-cooling refrigerator, and then passes through the impedance (117) to generate throttling refrigeration and liquefy into 4 He liquid to replenish the liquid helium pool (116) 4 He liquid.

7. The condenser pump type dilution refrigerator with a booster pump according to claim 6, wherein: It also includes a pre-cooling heat exchanger (113) arranged in the liquid helium pool (116), the high-pressure buffer tank (112) 3 The He gas passes through the first-stage regenerator (107) and then through the pre-cooling heat exchanger (113) before entering the second-stage regenerator (106).

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