Valve separation type parallel structure bidirectional air inlet pulse tube refrigerator

Abstract

According to the valve separation type parallel structure two-way air inlet pulse tube refrigerating machine, two or more two-way air inlet pulse tube refrigerating machines are integrated on one flange and share one valve separation type air distribution valve, air inlet and air return are executed through the same air distribution structure, and therefore the two-way air inlet pulse tube refrigerating machine system can achieve the larger refrigerating capacity, and meanwhile the refrigerating efficiency is improved. The problem that the efficiency of a heat regenerator is reduced due to the fact that a single refrigerating machine uses the heat regenerator and the pulse tube with larger sizes is solved. In addition, due to the fact that the two-way air inlet pulse tube refrigerating machines are arranged in parallel, air paths are of a symmetrical structure, and vibration can be effectively restrained.

Description

Technical Field

[0001] The present invention relates to the field of refrigerator technology, preferably to the field of dilution refrigerator technology applied to quantum computers, and in particular to a valve-separated parallel-structured bidirectional air-intake pulse tube refrigerator. Background Art

[0002] Dilution refrigerators are of great significance in promoting the development of quantum computing technology and are related to the performance of quantum computers. Valve-separated pulse tube refrigerators have low vibration and can be electrically isolated. They are widely used as dilution refrigerators in quantum computers and are one of their core components. At present, the mainstream models of valve-separated pulse tube refrigerators have a cooling capacity of about 1.5-2.0W at 4.2K. As the number of quantum bits manipulated by quantum computing increases, the cooling capacity requirements for pulse tube refrigerators are increasing. At present, a quantum computer that manipulates 1000 quantum bits requires a pulse tube refrigerator with a cooling capacity of 4.2K and a cooling capacity of 4.5W. For this purpose, three 4.2K refrigerators with a cooling capacity of 1.5-2.0W can usually be integrated together, or a 4.2K pulse tube refrigerator with a cooling capacity of 4.5W can be used. Using a pulse tube refrigerator with a large cooling capacity of 4.5W can reduce the volume occupancy by at least 50% compared to using three pulse tube refrigerators with a small cooling capacity of 1.5-2.0W, and can reduce the resonance problem of multiple pulse tube refrigerators running together. However, in the development of valve-separated pulse tube refrigerators with larger cooling capacity, the most direct and effective technical route is to increase the volume of the pulse tube and the regenerator. However, as the volume increases, the efficiency of the regenerator will drop sharply. This is also a problem and challenge in the development of pulse tube refrigerators with larger cooling capacity. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problems discussed above, and thus provide a valve separation type parallel structure two-way air intake pulse tube refrigerator, which is as follows: A valve-separated parallel structure bidirectional air intake pulse tube refrigerator, which is composed of a compressor, a separate gas distribution valve and two or more bidirectional air intake pulse tube refrigerators. The two or more pulse tube refrigerators are integrated and connected on the same flange in a parallel structure, and share a separate gas distribution valve and a compressor. The compressor intake and return air are performed by the same separate gas distribution valve. At the same time, the two or more bidirectional air intake pulse tube refrigerators are arranged in a circular symmetrical manner along the radial direction around the main air inlet and outlet located at the center of the flange, so that the mechanical forces generated by the air flow passing through the primary and secondary pulse tube gas reservoir holes and the primary and secondary bidirectional air intake holes of each pulse tube refrigerator can offset each other.

[0004] Further, each bidirectional air inlet pulse tube refrigerator integrated on the same flange comprises a primary pulse tube gas reservoir, a secondary pulse tube gas reservoir, a primary pulse tube gas reservoir small hole, a secondary pulse tube gas reservoir small hole, a primary pulse tube bidirectional air inlet small hole, a secondary pulse tube bidirectional air inlet small hole, a primary pulse tube hot end heat exchanger, a secondary pulse tube hot end heat exchanger, a primary pulse tube, a secondary pulse tube, a primary regenerator, a secondary regenerator, a primary cold end copper block, a primary pulse tube and regenerator connecting passage, a secondary pulse tube and regenerator connecting passage, a secondary pulse tube cold end heat exchanger and a secondary cold end copper block; Furthermore, each bidirectional inlet pulse tube refrigerator may include a regenerator and a heat exchanger of different structures; Furthermore, each bidirectional air inlet pulse tube refrigerator can share the primary and secondary cold end copper blocks in the refrigerator section; Furthermore, as an optional technical solution, each bidirectional air inlet pulse tube refrigerator can be provided with a primary and a secondary cold end copper block respectively; Furthermore, each bidirectional inlet pulse tube refrigerator can be phase-adjusted to achieve the best refrigeration performance; On the basis of the above content, the present invention further provides a control method for a valve-separated parallel structure bidirectional air intake pulse tube refrigerator, comprising the following steps: S1: control the compressor to start, and send the compressed high-pressure helium to the separated air distribution valve; S2: control the separated air distribution valve to rotate to the air intake state, and the helium evenly enters each bidirectional air intake pulse tube refrigerator after passing through the intersection; S3: the temperature of the helium decreases after entering the first-stage heat regenerator of each bidirectional air intake pulse tube refrigerator to release heat, and a part of the cooled helium enters the first-stage pulse tube to compress the helium in the first-stage pulse tube, and the compressed helium dissipates heat through the first-stage pulse tube hot end heat exchanger, and the first-stage phase modulation is performed by adjusting the opening of the small hole of the first-stage pulse tube gas reservoir; S4: the other part of the cooled helium enters The secondary regenerator further cools down the gas, and the cooled helium enters the secondary pulse tube to compress the helium in the secondary pulse tube. The compressed helium dissipates heat in the secondary pulse tube hot end heat exchanger, and the secondary phase adjustment is performed by adjusting the opening of the secondary pulse tube gas reservoir small hole; S5: the first-stage pulse tube two-way air intake small hole and the second-stage pulse tube two-way air intake small hole between the compressor outlet and the first-stage pulse tube hot end heat exchanger and the second-stage pulse tube hot end heat exchanger are adjusted to realize two-way air intake regulation; S6: the separate gas distribution valve is controlled to rotate to the return air state, so that the compressed helium in the first-stage pulse tube and the second-stage pulse tube expands and cools down, thereby reducing the temperature of the first-stage pulse tube cold end copper block and the second-stage pulse tube cold end copper block; S7: after passing through the first-stage regenerator and the second-stage regenerator, the helium returns to the compressor return air port through the gas distribution valve to complete the cycle.

[0005] The present invention integrates more than two bidirectional air inlet pulse tube refrigerators into one flange and shares a valve-separated gas distribution valve, so that the pulse tube refrigerator system can achieve a larger cooling capacity while avoiding the problem of reduced regenerator efficiency caused by using a larger-sized regenerator and pulse tube in a single refrigerator. Furthermore, the air intake and return air of the valve-separated parallel structure two-way air intake pulse tube refrigerator are performed by the same air distribution structure, and more than two two-way air intake pulse tube refrigerators are arranged in a circular symmetry in the radial direction around the air inlet and outlet located at the center of the flange, so that the mechanical forces generated by the air flow passing through the primary and secondary pulse tube gas reservoir holes and the primary and secondary pulse tube two-way air intake holes of each pulse tube refrigerator can offset each other, so that the air paths of multiple two-way air intake pulse tube refrigerators are also in a symmetrical structure, which can effectively suppress vibration; further, each pulse tube refrigerator can include regenerators and heat exchangers of different structures, thereby providing a combination of different cooling capacities to improve the applicability of the refrigerator to different occasions and needs; further, each pulse tube refrigerator can be phase-adjusted separately to achieve the best performance of each pulse tube refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0007] Figure 1 : Schematic diagram of a valve-separated parallel structure bidirectional air-intake pulse tube refrigerator; Figure 2 : Schematic diagram of the airflow direction of the pulse tube gas reservoir holes and the two-way air inlet holes of a single two-way air inlet pulse tube refrigerator; Figure 3 : Schematic diagram of the airflow of the pulse tube gas reservoir aperture and the bidirectional air inlet aperture of the valve separation parallel structure bidirectional air inlet pulse tube refrigerator of the present application; Figure 4 : Airflow distribution structure diagram including two bidirectional air inlet pulse tube refrigerators; Figure 5 : Airflow distribution structure diagram including three bidirectional air inlet pulse tube refrigerators; Figure 6 : Schematic diagram of vibration test direction of bidirectional air inlet pulse tube refrigerator; Figure 7 : Comparison of the dimensions of a 9.0w@4.2K valve-separated parallel-structure bidirectional air-intake pulse tube refrigerator and a 4.5w@4.2K bidirectional air-intake pulse tube refrigerator.

[0008] Reference numerals: 1- compressor; 2- separate gas distribution valve; 3- first-level pulse tube gas reservoir; 4- second-level pulse tube gas reservoir; 5- first-level pulse tube gas reservoir small hole; 6- second-level pulse tube gas reservoir small hole; 7- first-level pulse tube two-way air inlet small hole; 8- second-level pulse tube two-way air inlet small hole; 9- first-level pulse tube hot end heat exchanger; 10- second-level pulse tube hot end heat exchanger; 11- first-level pulse tube; 12- second-level pulse tube; 13- first-level regenerator; 14- first-level pulse tube cold end heat exchanger; 15- first-level cold end copper block; 16- second-level regenerator; 17- first-level pulse tube and regenerator connecting passage; 18- second-level pulse tube and regenerator connecting passage; 19- second-level pulse tube cold end heat exchanger; 20- second-level cold end copper block; 21- intersection. DETAILED DESCRIPTION

[0009] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. It is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0010] Figure 1 The valve separation type parallel structure bidirectional air intake pulse tube refrigerator shown includes two bidirectional air intake pulse tube refrigerators arranged in parallel, and the two bidirectional air intake pulse tube refrigerators arranged in parallel are completely identical in structure and include the same components. Obviously, in other embodiments, more than two bidirectional air intake pulse tube refrigerators arranged in parallel may also be included.

[0011] exist Figure 1 In the figure, two bidirectional air intake pulse tube refrigerators arranged in parallel are integrated and connected on the same flange, and share a separate type gas distribution valve 2 and a compressor 1, thereby forming a valve separation type parallel structure bidirectional air intake pulse tube refrigerator. Among them, the two bidirectional air intake pulse tube refrigerators integrated and connected on the same flange include the same components, so the same reference numerals are used to mark the same components. Specifically, each bidirectional air inlet pulse tube refrigerator includes a first-level pulse tube gas reservoir 3, a second-level pulse tube gas reservoir 4, a first-level pulse tube gas reservoir small hole 5, a second-level pulse tube gas reservoir small hole 6, a first-level pulse tube bidirectional air inlet small hole 7, a second-level pulse tube bidirectional air inlet small hole 8, a first-level pulse tube hot end heat exchanger 9, a second-level pulse tube hot end heat exchanger 10, a first-level pulse tube 11, a second-level pulse tube 12, a first-level regenerator 13, a second-level regenerator 16, a first-level pulse tube cold end heat exchanger 14, a first-level cold end copper block 15, a first-level pulse tube and regenerator connecting passage 17, a second-level pulse tube and regenerator connecting passage 18, a second-level pulse tube cold end heat exchanger 19 and a second-level cold end copper block 20.

[0012] As an optional embodiment, the specific structures of the regenerator (including the primary regenerator 13 and the secondary regenerator 16) and the heat exchanger (including the primary pulse tube hot end heat exchanger 9 and the secondary pulse tube hot end heat exchanger 10) of each bidirectional air inlet pulse tube refrigerator can be the same or different, that is, the specific structures of the regenerator and heat exchanger of each bidirectional air inlet pulse tube refrigerator can be different from the regenerator and heat exchanger of other bidirectional air inlet pulse tube refrigerators in parallel. Different structures of regenerator and heat exchanger can make the valve separation type parallel structure bidirectional air inlet pulse tube refrigerator adapt to different designs and applications, and provide refrigerators with different cooling capacity combinations according to actual needs to improve its adaptability.

[0013] Two or more bidirectional air-inlet pulse tube refrigerators arranged in parallel can share the primary cold-end copper block 15 and the secondary cold-end copper block 20 in the refrigerator part. Of course, as an optional technical solution, two or more bidirectional air-inlet pulse tube refrigerators arranged in parallel can be provided with the primary cold-end copper block 15 and the secondary cold-end copper block 20 separately. By separating the primary cold-end copper block 15 and the secondary cold-end copper block 20, each bidirectional air-inlet pulse tube refrigerator in parallel can be tested for small hole phase adjustment and cooling capacity, thereby speeding up the production and testing process.

[0014] The phase adjustment method of the two-stage pulse tube refrigerator with a two-way air intake structure is mainly achieved by adjusting the opening of the two-way air intake valve, so as to change the phase angle between the pressure wave and the velocity wave in the pulse tube, thereby affecting the cooling effect. The opening of the two-way air intake valve has a significant effect on the cooling capacity of the pulse tube refrigerator. When the opening of the two-way air intake valve is appropriate, the phase angle between the pressure wave and the velocity wave of the gas at the hot end of the pulse tube can be reduced, and the cooling performance of the two-way air intake pulse tube refrigerator can be effectively improved. By properly adjusting the opening of the two-way air intake valve, the cooling performance of the pulse tube refrigerator can be further improved on the basis of the small-hole pulse tube refrigerator. When the opening of the two-way air intake valve is a certain value, the cooling capacity reaches the maximum value, but as the diameter of the two-way air intake valve is further increased, the cooling capacity gradually decreases.

[0015] In order to enable each bidirectional air-inlet pulse tube refrigerator to achieve its own optimal refrigeration performance, the present invention can perform phase adjustment on each bidirectional air-inlet pulse tube refrigerator separately, that is, adjust the first-level pulse tube bidirectional air-inlet hole 7 and the second-level pulse tube bidirectional air-inlet hole 8 of each bidirectional air-inlet pulse tube refrigerator separately; of course, for those skilled in the art, performing phase adjustment at the same time is also an optional phase adjustment method according to actual situation needs.

[0016] Figure 2 The schematic diagram of the airflow direction of the pulse tube gas reservoir hole and the two-way air inlet hole of a single two-way air inlet pulse tube refrigerator is shown. Figure 3 The schematic diagram of the pulse tube gas reservoir aperture and the bidirectional air intake aperture of the valve separation parallel structure bidirectional air intake pulse tube refrigerator of the present application is shown. It should be noted that: Figure 2and 3 The arrow in the middle shows the direction of the airflow, which is used to describe how the gas flows and to visually demonstrate the vibrations that may be caused by the airflow.

[0017] like Figure 2 As shown, in a typical single two-way air inlet pulse tube refrigerator, the airflows flowing into the two pulse tube gas reservoir holes (i.e., the first-stage pulse tube gas reservoir hole 5 and the second-stage pulse tube gas reservoir hole 6) and the two two-way air inlet holes (i.e., the first-stage pulse tube two-way air inlet hole 7 and the second-stage pulse tube two-way air inlet hole 8) are arranged in a unilateral manner (e.g., Figure 2 As shown by the arrow in the middle, since the air inlet and outlet are not located at the center of the flange, the air flow flows back and forth along the above-mentioned small holes and causes vibration. If multiple refrigerators are arranged on the dilution refrigerator in this way, since the pulse tube refrigerators have the same operating frequency, the resonance caused by them will cause the vibration amplitude to increase.

[0018] Figure 3 This is a schematic diagram of the pulse tube gas reservoir aperture and the bidirectional air intake aperture of the valve separation parallel structure bidirectional air intake pulse tube refrigerator of the present application, which includes two bidirectional air intake pulse tube refrigerators arranged in parallel according to the structure of the present application. Arrows are also used to indicate the specific flow direction of the airflow to facilitate understanding of how the technical solution of the present application balances the force generated by the airflow on the mechanical structure. Figure 3 As shown, in the valve-separated parallel structure bidirectional air-inlet pulse tube refrigerator of the present invention, the two refrigerators are arranged symmetrically in a circular pattern along the radial direction around the air inlet and outlet ports at the center of the flange. Such a structure arrangement allows the airflow passing through four small holes (i.e., two primary pulse tube air reservoir small holes 5 and two secondary pulse tube air reservoir small holes 6) and four bidirectional air-inlet small holes (two primary pulse tube bidirectional air-inlet small holes 7 and two secondary pulse tube bidirectional air-inlet small holes 8) to be symmetrically distributed. In this way, when the airflow flows back and forth, the force of the airflow on the mechanical structure can be balanced, thereby reducing vibration.

[0019] like Figure 4 As shown, the air flow distribution structure including two bidirectional air inlet pulse tube refrigerators is shown. The arrows in the figure indicate the gas flow direction, which is used to show how the air flow flows. The air inlet and outlet are located at the center of the flange; taking the air intake process as an example, the gas enters from the air inlet and outlet and enters the two refrigerators respectively. The two air flows are 180 degrees opposite in direction, that is, they are arranged symmetrically in the radial direction around the air inlet and outlet located at the center of the flange. Taking one of the refrigerators as an example, most of the gas entering one of the refrigerators enters the primary regenerator 13, and a small part enters the primary pulse tube 11 and the secondary pulse tube 12 through the primary pulse tube bidirectional air inlet hole 7 and the secondary pulse tube bidirectional air inlet hole 8. Part of this part of the gas enters the primary pulse tube gas reservoir 3 and the secondary pulse tube gas reservoir 4. Similarly, the gas flow entering the other refrigerator is the same and will not be repeated.

[0020] and Figure 4 Similar effect, Figure 5 The embodiment of the invention includes three bidirectional air inlet pulse tube refrigerators arranged in parallel. The three bidirectional air inlet pulse tube refrigerators are symmetrically distributed along the radial direction around the air inlet and outlet of the flange center, that is, each bidirectional air inlet pulse tube refrigerator is evenly distributed in a 120-degree circle, so that the primary pulse tube and the secondary pulse tube of each bidirectional air inlet pulse tube refrigerator are also symmetrically distributed at a certain angle, and the mechanical forces generated by the air flow passing through the flow channel and the pulse tube gas reservoir holes (including three primary pulse tube gas reservoir holes 5 and three secondary pulse tube gas reservoir holes 6) and the bidirectional air inlet holes (including three primary pulse tube bidirectional air inlet holes 7 and three secondary pulse tube bidirectional air inlet holes 8) can offset each other and reduce vibration. For those skilled in the art, Figure 5 The structure shown is to further clarify the arrangement of multiple refrigerators in parallel. The airflow is still indicated by arrows, and its specific structure is the same as Figure 4 Similar, no further elaboration is required here.

[0021] like Figure 6 As shown, the present invention distributes the air inlet and outlet of each bidirectional air inlet pulse tube refrigerator in a circularly symmetrical manner along the radial direction around the center of the flange, so that the bidirectional air inlet holes and the pulse tube gas reservoir holes of each bidirectional air inlet pulse tube refrigerator are also distributed in a circularly symmetrical manner, thereby reducing vibrations in the three directions of X, Y and Z.

[0022] The vibration of a valve-separated parallel-type bidirectional air-intake pulse tube refrigerator with a cooling capacity of 3.0W@4.2K according to the structural arrangement of the present application and a typical bidirectional air-intake pulse tube refrigerator with a cooling capacity of 1.5W@4.2K are compared, and the comparison results are shown in Table 1: Table 1 Vibration comparison table

[0023] like Figure 7 As shown, the sizes of a valve-separated parallel-structured bidirectional air-intake pulse tube refrigerator with a cooling capacity of 9.0W@4.2K according to the structural arrangement of the present application are compared with two bidirectional air-intake pulse tube refrigerators with a cooling capacity of 4.5W@4.2K. The comparison results are shown in Table 2: Table 2 Pulse tube refrigerator size comparison table

[0024] In terms of installation area, which is usually determined by the normal temperature flange diameter, the 9.0W@4.2K valve-separated parallel-structured bidirectional air-intake pulse tube refrigerator saves (100%-300^2 / 458^2)=57% of installation area compared to using two 4.5W@4.2K bidirectional air-intake pulse tube refrigerators.

[0025] Based on the above content, the present invention further provides a control method for a valve-separated parallel structure pulse tube refrigerator, comprising the following steps: S1: Control the compressor 1 to start and send the compressed high-pressure helium to the separate gas distribution valve 2; S2: Control the rotation of the separate gas distribution valve 2 to the intake state, so that the helium gas passes through the intersection 21 and evenly enters the two two-way intake pulse tube refrigerators; S3: The temperature of the helium gas after entering the primary regenerator 13 of each two-way air inlet pulse tube refrigerator is reduced after heat release. A part of the cooled helium gas enters the primary pulse tube 11 to compress the helium gas in the primary pulse tube 11. The compressed helium gas dissipates heat through the primary pulse tube hot end heat exchanger 9, and the primary phase modulation is performed by adjusting the opening of the primary pulse tube gas reservoir small hole 5; S4: another part of the cooled helium enters the secondary regenerator 16 for further cooling, and the cooled helium enters the secondary pulse tube 12 to compress the helium in the secondary pulse tube 12, and the compressed helium dissipates heat in the secondary pulse tube hot end heat exchanger 10, and the secondary phase modulation is performed by adjusting the opening of the secondary pulse tube gas reservoir small hole 6; S5: adjusting the primary pulse tube bidirectional air inlet orifice 7 and the secondary pulse tube bidirectional air inlet orifice 8 between the air outlet of the compressor 1 and the primary pulse tube hot end heat exchanger 9 and the secondary pulse tube hot end heat exchanger 10 to achieve bidirectional air inlet regulation; S6: Control the separate gas distribution valve 2 to rotate to the return gas state, so that the compressed helium in the primary pulse tube and the secondary pulse tube 12 expands and cools down, thereby reducing the temperature of the primary cold end copper block 15 and the secondary cold end copper block 20; S7: After passing through the primary regenerator 13 and the secondary regenerator 16, the helium returns to the return air port of the compressor 1 through the separate gas distribution valve 2 to complete the cycle.

[0026] Furthermore, each bidirectional air inlet pulse tube refrigerator can be phase-adjusted separately to achieve the best performance of each bidirectional air inlet pulse tube refrigerator.

[0027] The present invention integrates more than two bidirectional air-intake pulse tube refrigerators into one flange and shares a valve-separated gas distribution valve, so that the bidirectional air-intake pulse tube refrigerator system can achieve a larger cooling capacity while avoiding the problem of reduced regenerator efficiency caused by the use of a larger-sized regenerator and pulse tube in a single bidirectional air-intake pulse tube refrigerator. Furthermore, the air intake and return of the valve-separated parallel structure bidirectional air-intake pulse tube refrigerator are performed by the same gas distribution structure, so that the gas circuits of multiple bidirectional air-intake pulse tube refrigerators are also in a symmetrical structure, which can effectively suppress vibration; further, each bidirectional air-intake pulse tube refrigerator can include a regenerator and a heat exchanger of different structures, thereby providing a combination of different cooling capacities to improve the applicability of the refrigerator to different occasions and needs; further, each bidirectional air-intake pulse tube refrigerator can be phase-adjusted separately to achieve the best performance of each bidirectional air-intake pulse tube refrigerator.

[0028] The above is a detailed introduction to a valve separation type parallel structure pulse tube refrigerator provided by the present invention. This article uses specific examples to illustrate the principle and implementation of the present invention. The description of the above embodiment is only used to help understand the method and core idea of ​​the present invention. For ordinary technicians in this field, the technical solution of the present invention is not limited to the solution defined by the specific implementation method. The technical solutions formed by other changes that can be obviously realized according to the common technical knowledge in this field are all within the protection scope of the present invention.

Claims

1. A valve-separated parallel structure bidirectional air intake pulse tube refrigerator, comprising a compressor, a separated gas distribution valve and two or more bidirectional air intake pulse tube refrigerators, characterized in that: Two or more pulse tube refrigerators are integrated and connected on the same flange in a parallel structure, and share a separate air distribution valve and compressor. The compressor air intake and return air are performed by the same separate air distribution valve; at the same time, two or more two-way air intake pulse tube refrigerators are arranged in a circular symmetrical manner along the radial direction around the air inlet and outlet located at the center of the flange, so that the mechanical forces generated by the air flow passing through the primary and secondary pulse tube gas reservoir holes and the primary and secondary pulse tube two-way air intake holes of each pulse tube refrigerator offset each other.

2. The valve-separated parallel structure bidirectional air-intake pulse tube refrigerator as described in claim 1, each bidirectional air-intake pulse tube refrigerator integrated on the same flange comprises a first-level pulse tube gas reservoir, a second-level pulse tube gas reservoir, a first-level pulse tube gas reservoir hole, a second-level pulse tube gas reservoir hole, a first-level pulse tube bidirectional air-intake hole, a second-level pulse tube bidirectional air-intake hole, a first-level pulse tube hot end heat exchanger, a second-level pulse tube hot end heat exchanger, a first-level pulse tube, a second-level pulse tube, a first-level regenerator, a second-level regenerator, a first-level cold end, a first-level pulse tube and regenerator connecting passage, a second-level pulse tube and regenerator connecting passage, a second-level pulse tube cold end heat exchanger and a second-level cold end.

3. The valve-separated parallel-structured bidirectional air-inlet pulse tube refrigerator as described in claim 2, wherein each bidirectional air-inlet pulse tube refrigerator comprises a regenerator and a heat exchanger of different structures.

4. The valve-separated parallel structure bidirectional air-inlet pulse tube refrigerator as described in claim 2 or 3, wherein two or more bidirectional air-inlet pulse tube refrigerators share a cold end copper block at the primary cold end and the secondary cold end of the refrigerator part.

5. The valve-separated parallel-structured bidirectional air-inlet pulse tube refrigerator as claimed in claim 2 or 3, wherein two or more bidirectional air-inlet pulse tube refrigerators are provided with primary and secondary cold-end copper blocks respectively.

6. The valve-separated parallel-structured bidirectional air-inlet pulse tube refrigerator as claimed in claim 2 or 3, wherein each bidirectional air-inlet pulse tube refrigerator is phase-adjusted to achieve its respective optimal refrigeration performance.

7. A control method for a valve separation type parallel structure bidirectional air intake pulse tube refrigerator according to claims 2 to 6, comprising the following steps: S1: Control the compressor to start, and send the compressed high-pressure helium to the separate gas distribution valve; S2: Control the separate gas distribution valve to rotate to the intake state, and the helium evenly enters each two-way intake pulse tube refrigerator after passing through the intersection; S3: The temperature of the helium decreases after entering the first-stage regenerator of each two-way intake pulse tube refrigerator to release heat. A part of the cooled helium enters the first-stage pulse tube to compress the helium in the first-stage pulse tube. The compressed helium dissipates heat through the first-stage pulse tube hot end heat exchanger, and the first-stage phase adjustment is performed by adjusting the opening of the small hole of the first-stage pulse tube gas reservoir; S4: Another part of the cooled helium enters the second-stage regenerator for further cooling, and the cooled helium enters the second-stage pulse tube compressor The helium in the secondary pulse tube is compressed, and the compressed helium dissipates heat in the secondary pulse tube hot end heat exchanger, and the secondary phase adjustment is performed by adjusting the opening of the secondary pulse tube gas reservoir small hole; S5: the first-level pulse tube two-way air intake small hole and the second-level pulse tube two-way air intake small hole between the compressor outlet and the first-level pulse tube hot end heat exchanger and the second-level pulse tube hot end heat exchanger are adjusted to realize two-way air intake regulation; S6: the separate air distribution valve is controlled to rotate to the return air state, so that the compressed helium in the first-level pulse tube and the second-level pulse tube expands and cools down, thereby reducing the temperature of the first-level pulse tube cold end and the second-level pulse tube cold end; S7: the helium passes through the first-level regenerator and the second-level regenerator and returns to the compressor return air port through the air distribution valve to complete the cycle.

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