A valve-separated parallel structure bidirectional air-intake pulse tube refrigerator

Abstract

The present invention provides a valve-separated parallel bidirectional air-inlet pulse tube refrigerator. By integrating two or more bidirectional air-inlet pulse tube refrigerators onto a single flange and sharing a valve-separated air distribution valve, the air supply and return are handled by the same air distribution structure. This enables the bidirectional air-inlet pulse tube refrigerator system to achieve a higher cooling capacity while avoiding the reduced regenerator efficiency associated with the larger regenerator and pulse tube required by a single refrigerator. Furthermore, the parallel arrangement of multiple bidirectional air-inlet pulse tube refrigerators creates a symmetrical gas path, effectively suppressing vibration.

Description

Technical Field

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

[0002] Dilution refrigerators are crucial for advancing quantum computing technology and are crucial for the performance of quantum computers. Valve-separated pulse tube refrigerators (VTCs) offer low vibration and electrical isolation, making them widely used as dilution refrigerators in quantum computers and a core component. Currently, mainstream valve-separated pulse tube refrigerators have a cooling capacity of approximately 1.5-2.0W at 4.2K. As the number of qubits manipulated in quantum computing increases, the cooling capacity requirements for pulse tube refrigerators are increasing. Currently, a quantum computer manipulating 1,000 qubits requires a pulse tube refrigerator with a cooling capacity of 4.5W at 4.2K. This is typically achieved by integrating three 4.2K 1.5-2.0W refrigerators or by using a single 4.2K 4.5W pulse tube refrigerator. Using a single 4.5W pulse tube refrigerator reduces the volume by at least 50% compared to using three 1.5-2.0W pulse tube refrigerators and reduces resonance issues associated with operating multiple pulse tube refrigerators simultaneously. However, in developing 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 developing pulse tube refrigerators with larger cooling capacity. Summary of the Invention

[0003] The present invention aims to solve the technical problems discussed above, and thus provides a valve-separated parallel structure bidirectional air inlet pulse tube refrigerator, specifically as follows:

[0004] A valve-separated parallel structure bidirectional air-intake pulse tube refrigerator consists of a compressor, a separated air 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 separated air distribution valve and compressor. The compressor air intake and return air are performed by the same separated air 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 when flowing through the first-level pulse tube gas reservoir orifice, the second-level pulse tube gas reservoir orifice and the first-level pulse tube bidirectional air inlet orifice and the second-level pulse tube bidirectional air inlet orifice of each pulse tube refrigerator can offset each other.

[0005] Furthermore, each bidirectional air inlet 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 orifice, a second-level pulse tube gas reservoir orifice, a first-level pulse tube bidirectional air inlet orifice, a second-level pulse tube bidirectional air inlet orifice, 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 copper block, a connecting passage between the first-level pulse tube and the regenerator, a connecting passage between the second-level pulse tube and the regenerator, a second-level pulse tube cold-end heat exchanger, and a second-level cold-end copper block.

[0006] Furthermore, each bidirectional air inlet pulse tube refrigerator includes a regenerator and a heat exchanger of different structures;

[0007] Furthermore, 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;

[0008] Furthermore, as an optional technical solution, each bidirectional air inlet pulse tube refrigerator can be separately provided with a primary cold end copper block and a secondary cold end copper block;

[0009] Furthermore, each bidirectional inlet pulse tube refrigerator can be phase-adjusted to achieve its own optimal cooling performance;

[0010] 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: controlling the compressor to start and send the compressed high-pressure helium into the separated air distribution valve; S2: controlling 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 helium enters the first-stage regenerator of each bidirectional air intake pulse tube refrigerator and releases 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 adjustment 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 the helium, 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 hole; S5: The primary pulse tube two-way air inlet hole and the secondary pulse tube two-way air inlet hole between the compressor outlet and the primary pulse tube hot end heat exchanger and the secondary pulse tube hot end heat exchanger are adjusted to achieve 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 primary and secondary pulse tubes expands and cools, thereby reducing the temperature of the primary pulse tube cold end copper block and the secondary pulse tube cold end copper block; S7: After passing through the primary regenerator and the secondary regenerator, the helium returns to the compressor return air port through the air distribution valve to complete the cycle.

[0011] The present invention integrates two or more 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 the use of a larger regenerator and pulse tube in a single refrigerator. Furthermore, the air intake and return air of the valve-separated parallel structure bidirectional air intake pulse tube refrigerator are performed by the same air distribution structure, and more than two bidirectional air intake pulse tube refrigerators are arranged in a radially symmetrical manner around the air inlet and outlet located in 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 bidirectional air intake holes of each pulse tube refrigerator can offset each other. In this way, the air paths of multiple bidirectional air intake pulse tube refrigerators are also in a symmetrical structure, which can effectively suppress vibration; furthermore, 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; furthermore, each pulse tube refrigerator can be phase-adjusted separately to achieve the optimal performance of each pulse tube refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0013] Figure 1 : Schematic diagram of a valve-separated parallel structure bidirectional air-inlet pulse tube refrigerator;

[0014] Figure 2 : Schematic diagram of the airflow direction of the pulse tube gas reservoir hole and the bidirectional air inlet hole of a single bidirectional air inlet pulse tube refrigerator;

[0015] 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;

[0016] Figure 4 : Airflow distribution structure diagram when including two bidirectional air inlet pulse tube refrigerators;

[0017] Figure 5 : Airflow distribution structure diagram when including three bidirectional air inlet pulse tube refrigerators;

[0018] Figure 6 : Schematic diagram of vibration test direction of bidirectional air inlet pulse tube refrigerator;

[0019] 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.

[0020] Reference numerals:

[0021] 1- Compressor; 2- Separate air distribution valve; 3- First-level pulse tube gas reservoir; 4- Second-level pulse tube gas reservoir; 5- First-level pulse tube gas reservoir orifice; 6- Second-level pulse tube gas reservoir orifice; 7- First-level pulse tube two-way air inlet orifice; 8- Second-level pulse tube two-way air inlet orifice; 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

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention 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, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without expending creative work are within the scope of protection of the present invention.

[0023] Figure 1 The illustrated valve-separated parallel bidirectional inlet pulse tube refrigerator includes two parallel bidirectional inlet pulse tube refrigerators. These two parallel bidirectional inlet pulse tube refrigerators are identical in structure and include the same components. Obviously, other embodiments may include more than two parallel bidirectional inlet pulse tube refrigerators.

[0024] exist Figure 1In the figure, two parallel bidirectional air-inlet pulse tube refrigerators are integrated and connected on a common flange, sharing a separate air distribution valve 2 and compressor 1, thereby forming a valve-separated parallel bidirectional air-inlet pulse tube refrigerator. The two bidirectional air-inlet pulse tube refrigerators integrated and connected on the same flange include the same components, and therefore identical components are labeled with the same reference numerals. 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 aperture 5, a second-level pulse tube gas reservoir aperture 6, a first-level pulse tube bidirectional air inlet aperture 7, a second-level pulse tube bidirectional air inlet aperture 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.

[0025] 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 pulse tube refrigerator can be the same or different. In other words, the specific structures of the regenerator and heat exchanger of each bidirectional pulse tube refrigerator can be different from those of other bidirectional pulse tube refrigerators connected in parallel. Different regenerator and heat exchanger structures enable the valve-separated parallel bidirectional pulse tube refrigerator to adapt to different designs and applications, and provide refrigerators with different cooling capacity combinations based on actual needs, thereby improving their adaptability.

[0026] Two or more bidirectional pulse tube refrigerators connected in parallel can share the primary cold-end copper block 15 and the secondary cold-end copper block 20 in the refrigerator section. Alternatively, each of the two or more bidirectional pulse tube refrigerators can have separate primary cold-end copper blocks 15 and secondary cold-end copper blocks 20. Separating the primary cold-end copper block 15 and the secondary cold-end copper block 20 allows for small-hole phase adjustment and cooling capacity testing of each parallel bidirectional pulse tube refrigerator, accelerating production and testing.

[0027] Phase modulation in a two-stage pulse tube refrigerator with a bidirectional inlet structure is primarily achieved by adjusting the opening of the bidirectional inlet valve. This alters the phase angle between the pressure and velocity waves within the pulse tube, thereby affecting the cooling efficiency. The bidirectional inlet valve opening significantly affects the cooling capacity of the pulse tube refrigerator. When the bidirectional inlet valve opening is appropriately adjusted, the phase angle between the pressure and velocity waves of the gas at the hot end of the pulse tube is reduced, effectively improving the cooling performance of the bidirectional inlet pulse tube refrigerator. By appropriately adjusting the bidirectional inlet valve opening, the cooling performance of the pulse tube refrigerator can be further improved compared to that of a small-hole pulse tube refrigerator. When the bidirectional inlet valve opening is at a certain value, the cooling capacity reaches its maximum. However, as the bidirectional inlet valve diameter is further increased, the cooling capacity gradually decreases.

[0028] 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, separately adjust the primary pulse tube bidirectional air-inlet orifice 7 and the secondary pulse tube bidirectional air-inlet orifice 8 of each bidirectional air-inlet pulse tube refrigerator. Of course, for those skilled in the art, simultaneous phase adjustment is also an optional phase adjustment method according to actual needs.

[0029] Figure 2 A schematic diagram showing the airflow direction of the pulse tube gas reservoir aperture and the bidirectional air inlet aperture of a single bidirectional air inlet pulse tube refrigerator is shown. Figure 3 The figure shows the flow diagram 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 2 and 3 The arrow in the middle indicates the direction of airflow, which is used to describe how the gas flows and to visually demonstrate the vibrations that may be caused by the airflow.

[0030] like Figure 2 As shown, in a typical single bidirectional air inlet pulse tube refrigerator, the air flows into the two pulse tube reservoir holes (i.e., the first-level pulse tube reservoir hole 5 and the second-level pulse tube reservoir hole 6) and the two bidirectional air inlet holes (i.e., the first-level pulse tube bidirectional air inlet hole 7 and the second-level pulse tube bidirectional air inlet hole 8) are arranged unilaterally (e.g., Figure 2 As shown by the arrows in the middle, since the air inlet and outlet are not located at the center of the flange, the airflow flows back and forth along the aforementioned small holes, causing vibration. If multiple refrigerators are arranged on a dilution refrigerator in this way, since the pulse tube refrigerators operate at the same frequency, the resonance caused by them will cause the vibration amplitude to increase.

[0031] Figure 3This is a schematic diagram of the pulse tube gas reservoir aperture and bidirectional air inlet aperture of the valve separation parallel structure bidirectional air inlet pulse tube refrigerator of this application. It includes two bidirectional air inlet pulse tube refrigerators arranged in parallel according to the structure of this application. The specific flow direction of the airflow is also indicated by arrows to facilitate understanding of how the technical solution of this 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 in a circular symmetrical manner along the radial direction around the air inlet and outlet ports in the center of the flange. Such a structure allows the airflow flowing through four small holes (i.e., two primary pulse tube air reservoir holes 5 and two secondary pulse tube air reservoir holes 6) and four bidirectional air-inlet holes (two primary pulse tube bidirectional air-inlet holes 7 and two secondary pulse tube bidirectional air-inlet 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, which can reduce vibration.

[0032] like Figure 4 The figure shows the airflow distribution structure when two bidirectional air inlet pulse tube refrigerators are included. The arrows in the figure indicate the direction of gas flow, which is used to show how the airflow 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 airflow directions are 180 degrees opposite, 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 first-level regenerator 13, and a small part enters the first-level pulse tube 11 and the second-level pulse tube 12 through the first-level pulse tube bidirectional air inlet hole 7 and the second-level pulse tube bidirectional air inlet hole 8. Part of this gas then enters the first-level pulse tube gas reservoir 3 and the second-level pulse tube gas reservoir 4. Similarly, the gas flow entering the other refrigerator is the same and will not be repeated.

[0033] and Figure 4 Similar effects, Figure 5 The embodiment shown includes three bidirectional pulse tube refrigerators arranged in parallel. The three bidirectional pulse tube refrigerators are symmetrically distributed radially around the inlet and outlet ports at the center of the flange. That is, each bidirectional pulse tube refrigerator is evenly distributed along a 120-degree circle. This ensures that the primary and secondary pulse tubes of each bidirectional pulse tube refrigerator are also symmetrically distributed at a certain angle. The mechanical forces generated by the airflow passing through the flow channel and the pulse tube air reservoir holes (including three primary pulse tube air reservoir holes 5 and three secondary pulse tube air reservoir holes 6) and the bidirectional air intake holes (including three primary pulse tube bidirectional air intake holes 7 and three secondary pulse tube bidirectional air intake holes 8) can thus offset each other, reducing vibration. For those skilled in the art, Figure 5 The structure shown is to further clarify the arrangement of multiple refrigerators in parallel. The air flow is still represented by arrows, and its specific structure is the same as Figure 4 Similar, no further description is given here.

[0034] like Figure 6 As shown, the present invention distributes the air inlet and outlet of each bidirectional air inlet pulse tube refrigerator in a circumferentially symmetrical 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 circumferentially symmetrical manner, thereby reducing vibration in the X, Y and Z directions.

[0035] The vibration of a valve-separated parallel-connected bidirectional air-intake pulse tube refrigerator with a cooling capacity of 3.0W@4.2K according to the structural arrangement of the present application was compared with a typical bidirectional air-intake pulse tube refrigerator with a cooling capacity of 1.5W@4.2K. The comparison results are shown in Table 1 below:

[0036] Table 1 Vibration comparison table

[0037] Vibration displacement x microns Vibration displacement y microns Vibration displacement z microns 3.0W@4.2K valve-separated parallel structure two-way air intake pulse tube refrigerator + / -5 + / -4 + / -13 1.5W@4.2K typical bidirectional air inlet pulse tube cooler + / -15 + / -5 + / -13

[0038] like Figure 7 As shown, the dimensions of a valve-separated parallel bidirectional air-inlet 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-inlet pulse tube refrigerators with a cooling capacity of 4.5W@4.2K. The comparison results are shown in Table 2:

[0039] Table 2 Pulse tube refrigerator size comparison

[0040] 9.0W@4.2K valve-separated parallel structure two-way air intake pulse tube refrigerator Single 4.5W@4.2K bidirectional air inlet pulse tube refrigerator Two 4.5W@4.2K bidirectional air inlet pulse tube coolers Normal temperature flange diameter 300mm 229mm 229mm*2=458mm First level flange diameter 220.9mm 164mm 164mm*2=328mm Secondary flange diameter 189mm 135mm 135mm*2=270mm

[0041] In terms of installation area, which is usually determined by the normal temperature flange diameter, a 9.0W@4.2K valve-separated parallel-structure 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.

[0042] 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:

[0043] S1: Control the compressor 1 to start and send the compressed high-pressure helium to the separate gas distribution valve 2;

[0044] 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 bidirectional intake pulse tube refrigerators;

[0045] S3: The helium enters the primary regenerator 13 of each bidirectional inlet pulse tube refrigerator and releases heat, whereupon its temperature drops. A portion of the cooled helium enters the primary pulse tube 11 to compress the helium in the primary pulse tube 11. The compressed helium dissipates heat through the primary pulse tube hot end heat exchanger 9, and primary phase modulation is performed by adjusting the opening of the primary pulse tube gas reservoir orifice 5.

[0046] S4: The other portion of the cooled helium enters the secondary regenerator 16 for further cooling. The cooled helium enters the secondary pulse tube 12 to compress the helium in the secondary pulse tube 12. The compressed helium dissipates heat in the secondary pulse tube hot end heat exchanger 10, and secondary phase modulation is performed by adjusting the opening of the secondary pulse tube gas reservoir orifice 6.

[0047] S5: Adjust the first-level pulse tube bidirectional air inlet orifice 7 and the second-level pulse tube bidirectional air inlet orifice 8 between the air outlet of the compressor 1 and the first-level pulse tube hot end heat exchanger 9 and the second-level pulse tube hot end heat exchanger 10 to achieve bidirectional air inlet regulation;

[0048] 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;

[0049] 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.

[0050] Furthermore, each bidirectional inlet pulse tube refrigerator can be phase-adjusted individually to achieve optimal performance of each bidirectional inlet pulse tube refrigerator.

[0051] By integrating two or more bidirectional pulse tube refrigerators onto a single flange and sharing a single valve-separated gas distribution valve, the present invention achieves a higher cooling capacity while avoiding the reduced regenerator efficiency associated with a single bidirectional pulse tube refrigerator, which typically requires a larger regenerator and pulse tube. Furthermore, the intake and return air flows of the valve-separated parallel bidirectional pulse tube refrigerators are handled by the same gas distribution structure, resulting in a symmetrical gas path structure for the multiple bidirectional pulse tube refrigerators, effectively suppressing vibration. Furthermore, each bidirectional pulse tube refrigerator can include regenerators and heat exchangers of different structures, thereby providing different cooling capacity combinations and improving the refrigerator's suitability for different applications and requirements. Furthermore, each bidirectional pulse tube refrigerator can be individually phase-adjusted to achieve optimal performance.

[0052] The above detailed description of the valve-separated parallel-connected pulse tube refrigerator provided by the present invention has been provided. Specific examples have been used to illustrate the principles and implementations of the present invention. The above examples are intended only to facilitate understanding of the present invention's methods and core concepts. For those skilled in the art, the present invention's technical solutions are not limited to the specific implementations described. Other variations readily achievable based on common technical knowledge in the art are also within the scope of this invention.

Claims

1. A valve-separated parallel structure bidirectional air-intake pulse tube refrigerator, comprising a compressor, a separated air 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 intake and return air are performed by the same separate air distribution valve; at the same time, the two or more bidirectional air inlet pulse tube refrigerators are arranged in a radially symmetrical manner around the air inlet and outlet located in the center of the flange, so that the mechanical forces generated when the air flow flows through the first-level pulse tube gas reservoir orifice, the second-level pulse tube gas reservoir orifice and the first-level pulse tube bidirectional air inlet orifice, and the second-level pulse tube bidirectional air inlet orifice 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 orifice, a second-level pulse tube gas reservoir orifice, a first-level pulse tube bidirectional air-intake orifice, a second-level pulse tube bidirectional air-intake orifice, 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 connecting passage between the first-level pulse tube and the regenerator, a connecting passage between the second-level pulse tube and the regenerator, a second-level pulse tube cold-end heat exchanger and a second-level cold end.

3. The valve-separated parallel-structure bidirectional air-intake pulse tube refrigerator according to claim 2, wherein each bidirectional air-intake 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 claimed in claim 2 or 3, wherein two or more bidirectional air-inlet pulse tube refrigerators share a common 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 according to claim 2 or 3, wherein two or more bidirectional air-inlet pulse tube refrigerators are respectively provided with a primary cold-end copper block and a secondary cold-end copper block.

6. The valve-separated parallel-structured bidirectional air-inlet pulse tube refrigerator according to 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-separated parallel-structure bidirectional air-intake pulse tube refrigerator according to claims 2-6, 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 passes through the intersection and evenly enters each two-way air intake pulse tube refrigerator; S3: The helium enters the first-stage regenerator of each two-way air intake pulse tube refrigerator and releases heat, and 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: The other part of the cooled helium enters the second-stage regenerator for further cooling, and the cooled helium enters the second-stage pulse tube refrigerator. 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 hole; S5: The primary pulse tube two-way air inlet hole and the secondary pulse tube two-way air inlet hole between the compressor outlet and the primary pulse tube hot end heat exchanger and the secondary 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 primary and secondary pulse tubes expands and cools down, thereby reducing the temperature of the primary and secondary pulse tube cold ends; S7: After passing through the primary regenerator and the secondary regenerator, the helium returns to the compressor return air port through the air distribution valve to complete the cycle.

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