Two-way intake pulse tube refrigerator having valve-separated parallel structure

Abstract

Provided in the present invention is a two-way intake pulse tube refrigerator having a valve-separated parallel structure. By integrating two or more two-way intake pulse tube refrigerators on one flange to share one valve-separated gas distribution valve, gas intake and return are executed by the same gas distribution structure, which enables the two-way intake pulse tube refrigerator system to achieve a larger cooling capacity, while avoiding the problem of the reduced efficiency of a regenerator caused by the use of a larger-sized regenerator and pulse tube in a single refrigerator. Moreover, since a plurality of two-way intake pulse tube refrigerators are arranged in parallel, a gas path is in a symmetrical structure, which can effectively suppress vibration.

Description

A valve-separated parallel structure bidirectional intake pulse tube refrigerator Technical Field

[0001] This invention relates to the field of refrigeration technology, preferably to the field of dilution refrigeration technology applied to quantum computers, and particularly to a valve-separated parallel structure bidirectional intake pulse tube refrigeration machine. Background Technology

[0002] Dilution refrigerators are crucial for advancing quantum computing technology and are directly related to the performance of quantum computers. Valve-separated pulse tube refrigerators, with their low vibration and electrical isolation capabilities, are widely used as dilution refrigerators in quantum computers and are one of their core components. Currently, the mainstream valve-separated pulse tube refrigerators have a cooling capacity of approximately 1.5-2.0W at 4.2K. As quantum computing manipulates an increasing number of qubits, the cooling capacity requirements for pulse tube refrigerators are growing. Currently, a quantum computer controlling 1000 qubits requires a pulse tube refrigerator with a cooling capacity of 4.5W at 4.2K. Therefore, it is common practice to integrate three 4.2K refrigerators with a cooling capacity of 1.5-2.0W each, or to use a single 4.2K pulse tube refrigerator with a cooling capacity of 4.5W. Using a single 4.5W pulse tube refrigerator reduces the volume footprint by at least 50% compared to using three 1.5-2.0W pulse tube refrigerators, and also reduces the resonance problem caused by multiple pulse tube refrigerators operating together. However, the most direct and effective technical approach to developing a valve-separated pulse tube refrigerator with a larger cooling capacity is to increase the volume of the pulse tube and the regenerator. But as the volume increases, the efficiency of the regenerator will drop sharply. This is also a problem and challenge in developing a pulse tube refrigerator with a larger cooling capacity. Summary of the Invention

[0003] The purpose of this invention is to solve the aforementioned technical problems, thereby providing a valve-separated parallel structure bidirectional intake pulse tube refrigerator, as detailed below:

[0004] A valve-separated parallel structure bidirectional air-intake pulse tube refrigerator comprises 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 in parallel on the same flange, sharing a single separate gas distribution valve and compressor. The compressor's intake and return air are controlled by the same separate gas distribution valve. Simultaneously, the two or more bidirectional air-intake pulse tube refrigerators are arranged symmetrically in a radial direction around the main inlet and outlet ports located at the center of the flange. This arrangement ensures that the mechanical forces generated by the airflow passing through the primary and secondary pulse tube gas reservoir orifices and the primary and secondary bidirectional air inlet orifices of each pulse tube refrigerator can cancel each other out.

[0005] Furthermore, each bidirectional inlet pulse tube refrigerator integrated on the same flange includes a primary pulse tube gas reservoir, a secondary pulse tube gas reservoir, a primary pulse tube gas reservoir orifice, a secondary pulse tube gas reservoir orifice, a primary pulse tube bidirectional inlet orifice, a secondary pulse tube bidirectional inlet orifice, 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 connection passage between the primary pulse tube and the regenerator, a connection passage between the secondary pulse tube and the regenerator, a secondary pulse tube cold-end heat exchanger, and a secondary cold-end copper block.

[0006] Furthermore, each bidirectional intake pulse tube refrigerator may include regenerators and heat exchangers with different structures;

[0007] Furthermore, each bidirectional intake pulse tube refrigerator can share the primary and secondary cold end copper blocks in the refrigerator section;

[0008] Furthermore, as an optional technical solution, each bidirectional intake pulse tube refrigerator can be equipped with separate primary and secondary cold end copper blocks;

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

[0010] Based on the above, the present invention further provides a control method for a valve-separated parallel structure bidirectional inlet pulse tube refrigerator, comprising the following steps: S1: Control the compressor to start, and send the compressed high-pressure helium gas into the separate gas distribution valve; S2: Control the separate gas distribution valve to rotate to the inlet state, and the helium gas enters each bidirectional inlet pulse tube refrigerator evenly after passing through the junction; S3: After the helium gas enters the first-stage regenerator of each bidirectional inlet pulse tube refrigerator and releases heat, the temperature decreases, and part of the cooled helium gas enters the first-stage pulse tube to compress the helium gas in the first-stage pulse tube. The compressed helium gas dissipates heat through the heat exchanger at the hot end of the first-stage pulse tube, and the first-stage phase adjustment is performed by adjusting the opening of the small orifice of the gas reservoir in the first-stage pulse tube; S4: The other part of the cooled helium gas enters The secondary regenerator further cools the helium, which then enters the secondary pulse tube to compress the helium within. The compressed helium dissipates heat in the hot-end heat exchanger of the secondary pulse tube, and secondary phase adjustment is achieved by adjusting the opening of the small orifice in the gas reservoir of the secondary pulse tube; S5: Adjust the bidirectional air inlet holes of the primary and secondary pulse tubes between the compressor outlet and the hot-end heat exchangers of the primary and secondary pulse tubes to achieve bidirectional air intake regulation; S6: Control the separate gas distribution valve to rotate to the return gas state, causing the compressed helium in the primary and secondary pulse tubes to expand and cool down, thereby reducing the temperature of the cold-end copper blocks of the primary and secondary pulse tubes; S7: After passing through the primary and secondary regenerators, the helium returns to the compressor return gas port through the gas distribution valve to complete the cycle.

[0011] This invention integrates two or more bidirectional air-intake pulse tube refrigerators onto a single flange, sharing a valve-separated gas distribution valve. This allows the pulse tube refrigerator system to achieve a greater cooling capacity while avoiding the problem of reduced regenerator efficiency caused by using larger regenerators and pulse tubes in a single refrigerator. Furthermore, in the valve-separated parallel structure bidirectional intake pulse tube refrigerator, the intake and return air are controlled by the same gas distribution structure. Two or more bidirectional intake pulse tube refrigerators are arranged symmetrically in the radial direction around the inlet and outlet ports located at the center of the flange. This allows the mechanical forces generated by the airflow passing through the primary and secondary pulse tube gas reservoirs and the primary and secondary bidirectional intake ports of each refrigerator to cancel each other out. This also ensures that the gas paths of multiple bidirectional intake pulse tube refrigerators are symmetrical, effectively suppressing vibration. Furthermore, each pulse tube refrigerator can include regenerators and heat exchangers with different structures, thereby providing different combinations of cooling capacity to improve the refrigerator's applicability to different applications and needs. Even further, each pulse tube refrigerator can be individually phase-tuned to achieve its optimal performance. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1: Schematic diagram of a valve-separated parallel structure bidirectional intake pulse tube refrigeration machine;

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

[0015] Figure 3: Schematic diagram of the airflow of the pulse tube gas reservoir orifice and the bidirectional air inlet orifice in the valve separation type parallel structure bidirectional air inlet pulse tube refrigerator of this application.

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

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

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

[0019] Figure 7: Comparison of the dimensions of the 9.0w@4.2K valve-separated parallel structure bidirectional intake pulse tube refrigerator and the 4.5w@4.2K bidirectional intake pulse tube refrigerator.

[0020] Figure reference numerals: 1-Compressor; 2-Separate gas distribution valve; 3-Primary pulse tube gas reservoir; 4-Secondary pulse tube gas reservoir; 5-Primary pulse tube gas reservoir orifice; 6-Secondary pulse tube gas reservoir orifice; 7-Primary pulse tube bidirectional inlet orifice; 8-Secondary pulse tube bidirectional inlet orifice; 9-Primary pulse tube hot-end heat exchanger; 10-Secondary pulse tube hot-end heat exchanger; 11-Primary pulse tube; 12-Secondary pulse tube; 13-Primary regenerator; 14-Primary pulse tube cold-end heat exchanger; 15-Primary cold-end copper block; 16-Secondary regenerator; 17-Connecting passage between primary pulse tube and regenerator; 18-Connecting passage between secondary pulse tube and regenerator; 19-Secondary pulse tube cold-end heat exchanger; 20-Secondary cold-end copper block; 21-Connection point. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. It is obvious that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] The valve-separated parallel structure bidirectional air-intake pulse tube refrigerator shown in Figure 1 includes two bidirectional air-intake pulse tube refrigerators connected in parallel. These two parallel bidirectional air-intake pulse tube refrigerators are structurally identical and include the same components. Obviously, in other embodiments, more than two bidirectional air-intake pulse tube refrigerators may also be included.

[0023] In Figure 1, two parallel bidirectional intake pulse tube refrigerators are integrated and connected on the same flange, sharing a separate gas distribution valve 2 and compressor 1, thus forming a valve-separated parallel bidirectional intake pulse tube refrigerator. Since the two bidirectional intake pulse tube refrigerators integrated on the same flange include identical components, the same reference numerals are used to label these identical components. Specifically, each bidirectional air intake pulse tube refrigerator includes a primary pulse tube gas reservoir 3, a secondary pulse tube gas reservoir 4, a primary pulse tube gas reservoir orifice 5, a secondary pulse tube gas reservoir orifice 6, a primary pulse tube bidirectional air intake orifice 7, a secondary pulse tube bidirectional air intake orifice 8, a primary pulse tube hot end heat exchanger 9, a secondary pulse tube hot end heat exchanger 10, a primary pulse tube 11, a secondary pulse tube 12, a primary regenerator 13, a secondary regenerator 16, a primary pulse tube cold end heat exchanger 14, a primary cold end copper block 15, a primary pulse tube and regenerator connection passage 17, a secondary pulse tube and regenerator connection passage 18, a secondary pulse tube cold end heat exchanger 19, and a secondary cold end copper block 20.

[0024] As an optional implementation, the specific structures of the regenerator (including the primary regenerator 13 and the secondary regenerator 16) and 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 inlet pulse tube refrigerator can be the same or different. That is, the specific structures of the regenerator and heat exchanger of each bidirectional inlet pulse tube refrigerator can differ from those of other bidirectional inlet pulse tube refrigerators connected in parallel. Different regenerator and heat exchanger structures allow the valve-separated parallel bidirectional inlet pulse tube refrigerator to adapt to different designs and applications, and provide refrigerators with different cooling capacity combinations according to actual needs to improve their adaptability.

[0025] Two or more bidirectional air-intake 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, as an optional technical solution, the primary cold-end copper block 15 and the secondary cold-end copper block 20 can be installed separately for each of the two parallel bidirectional air-intake pulse tube refrigerators. Separating the primary cold-end copper block 15 and the secondary cold-end copper block 20 allows for individual testing of the orifice phase adjustment and cooling capacity of each parallel bidirectional air-intake pulse tube refrigerator, accelerating the production and testing process.

[0026] The phase adjustment method of a two-stage pulse tube refrigerator with a bidirectional intake structure is mainly achieved by adjusting the opening of the bidirectional intake valve, thereby changing the phase angle between the pressure wave and velocity wave within the pulse tube, and thus affecting the cooling effect. The opening of the bidirectional intake valve has a significant impact on the cooling capacity of the pulse tube refrigerator. When the opening of the bidirectional intake valve is appropriate, the phase angle between the pressure wave and velocity wave of the gas at the hot end of the pulse tube can be reduced, effectively improving the cooling performance of the bidirectional intake pulse tube refrigerator. By appropriately adjusting the opening of the bidirectional intake valve, the cooling performance of the pulse tube refrigerator can be further improved based on the small-orifice pulse tube refrigerator. When the opening of the bidirectional intake valve is at a certain value, the cooling capacity reaches its maximum value, but as the diameter of the bidirectional intake valve further increases, the cooling capacity gradually decreases.

[0027] In order to enable each bidirectional air intake pulse tube refrigerator to achieve its optimal cooling performance, the present invention allows for individual phase adjustment of each bidirectional air intake pulse tube refrigerator, that is, adjusting the primary pulse tube bidirectional air intake orifice 7 and the secondary pulse tube bidirectional air intake orifice 8 of each bidirectional air intake pulse tube refrigerator individually; of course, for those skilled in the art, simultaneous phase adjustment is also an optional phase adjustment method depending on the actual situation.

[0028] Figure 2 shows a schematic diagram of the airflow direction of the pulse tube gas reservoir orifice and the bidirectional air intake orifice in a single bidirectional air intake pulse tube refrigerator. Figure 3 shows a schematic diagram of the airflow of the pulse tube gas reservoir orifice and the bidirectional air intake orifice in the valve-separated parallel structure bidirectional air intake pulse tube refrigerator of this application. It should be noted that the arrows in Figures 2 and 3 indicate the direction of airflow, used to describe how the gas flows, to visually demonstrate the vibration that the airflow may cause.

[0029] As shown in Figure 2, in a typical single bidirectional inlet pulse tube refrigerator, the airflow into two pulse tube gas reservoir holes (i.e., primary pulse tube gas reservoir hole 5 and secondary pulse tube gas reservoir hole 6) and two bidirectional inlet holes (i.e., primary pulse tube bidirectional inlet hole 7 and secondary pulse tube bidirectional inlet hole 8) is arranged on one side (as shown by the arrow in Figure 2). Since the inlet and outlet are not located at the center of the flange, the airflow flows back and forth along the above-mentioned holes, causing vibration. If multiple refrigerators are arranged on the dilution refrigerator in this way, the resonance caused by the pulse tube refrigerators operating at the same frequency will increase the vibration amplitude.

[0030] Figure 3 is a schematic diagram of the airflow through the pulse gas reservoir orifices and bidirectional air intake orifices of the valve-separated parallel structure bidirectional air intake pulse tube refrigerator of this application. It includes two bidirectional air intake pulse tube refrigerators arranged in parallel according to the structure of this application. Arrows are used to indicate the specific flow direction of the airflow to facilitate understanding how the technical solution of this application balances the force generated by the airflow on the mechanical structure. As shown in Figure 3, in the valve-separated parallel structure bidirectional air intake pulse tube refrigerator of this invention, the two refrigerators are arranged symmetrically in the radial direction around the air inlet and outlet ports at the center of the flange. This arrangement allows the airflow through the four orifices (i.e., two primary pulse gas reservoir orifices 5 and two secondary pulse gas reservoir orifices 6) and the four bidirectional air intake orifices (two primary pulse tube bidirectional air intake orifices 7 and two secondary pulse tube bidirectional air intake orifices 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, resulting in less vibration.

[0031] Figure 4 illustrates the airflow distribution structure when two bidirectional inlet pulse tube refrigerators are used. The arrows in the figure indicate the gas flow direction, showing how the airflow moves. The inlet and outlet are located at the center of the flange. Taking the inlet process as an example, gas enters through the inlet and outlet, flowing into both refrigerators. The two airflow directions are opposite, at 180 degrees, forming a symmetrical radial arrangement around the inlet and outlet located at the center of the flange. Taking one refrigerator as an example, most of the gas entering it enters the first-stage regenerator 13, while a small portion enters the first-stage pulse tube 11 and second-stage pulse tube 12 through the bidirectional inlet holes 7 and 8. A portion of this gas then enters the first-stage pulse tube gas reservoir 3 and the second-stage pulse tube gas reservoir 4. Similarly, the gas flow to the other refrigerator is the same and will not be described further.

[0032] Similar to Figure 4, Figure 5 shows an embodiment comprising three parallel bidirectional inlet pulse tube refrigerators. The three refrigerators are radially symmetrically distributed around the inlet and outlet ports at the center of the flange, meaning each refrigerator is evenly distributed at 120-degree circumferences. This ensures that the primary and secondary pulse tubes of each refrigerator are also symmetrically distributed at a certain angle. The mechanical forces generated by the airflow passing through the flow channels and pulse tube gas reservoir orifices (including three primary pulse tube gas reservoir orifices 5 and three secondary pulse tube gas reservoir orifices 6) and the bidirectional inlet orifices (including three primary pulse tube bidirectional inlet orifices 7 and three secondary pulse tube bidirectional inlet orifices 8) can thus cancel each other out, reducing vibration. For those skilled in the art, the structure shown in Figure 5 is to further clarify the arrangement of multiple refrigerators connected in parallel. Airflow is still indicated by arrows, and its specific structure is similar to that in Figure 4, and will not be described again here.

[0033] As shown in Figure 6, the present invention reduces vibration in the X, Y and Z directions by symmetrically distributing the inlet and outlet ports of each bidirectional air intake pulse tube refrigerator around the center of the flange in a radial direction. This results in the bidirectional air intake holes and pulse tube gas reservoir holes of each bidirectional air intake pulse tube refrigerator being symmetrically distributed in a circular shape.

[0034] The vibration of a valve-separated parallel bidirectional inlet pulse tube refrigerator with a cooling capacity of 3.0W@4.2K, arranged according to the structure of this application, and a typical bidirectional inlet pulse tube refrigerator with a cooling capacity of 1.5W@4.2K were compared. The comparison results are shown in Table 1 below:

[0035] Table 1 Vibration Comparison Table

[0036] As shown in Figure 7, the dimensions of a valve-separated parallel bidirectional inlet pulse tube refrigerator with a cooling capacity of 9.0W@4.2K, arranged according to the structure of this application, are compared with those of two bidirectional inlet pulse tube refrigerators with a cooling capacity of 4.5W@4.2K. The comparison results are shown in Table 2.

[0037] Table 2 Comparison of Dimensions of Pulse Tube Refrigeration Machines

[0038] In terms of installation area, which is usually determined by the diameter of the flange at normal temperature, the installation area saved by a 9.0W@4.2K valve-separated parallel structure bidirectional intake pulse tube refrigerator is (100%-300^2 / 458^2)=57% compared to using two 4.5W@4.2K bidirectional intake pulse tube refrigerators.

[0039] Based on the above, the present invention further provides a control method for a valve-separated parallel structure pulse tube refrigerator, comprising the following steps:

[0040] S1: Control compressor 1 to start, and send the compressed high-pressure helium gas into the separate gas distribution valve 2;

[0041] S2: Control the rotation of the separate gas distribution valve 2 to the intake state, so that helium gas enters the two bidirectional intake pulse tube refrigerators evenly after passing through the junction 21.

[0042] S3: After the helium gas enters the first-stage regenerator 13 of each bidirectional inlet pulse tube refrigerator and releases heat, the temperature decreases. A portion of the cooled helium gas enters the first-stage pulse tube 11 to compress the helium gas in the first-stage pulse tube 11. The compressed helium gas dissipates heat through the first-stage pulse tube hot end heat exchanger 9, and the first-stage phase adjustment is performed by adjusting the opening of the first-stage pulse tube gas reservoir orifice 5.

[0043] S4: Another portion of the cooled helium enters the secondary regenerator 16 for further cooling. The cooled helium then enters the secondary pulse tube 12 to compress the helium in the secondary pulse tube 12. The compressed helium dissipates heat in the heat exchanger 10 at the hot end of the secondary pulse tube, and secondary phase adjustment is performed by adjusting the opening of the small hole 6 in the gas reservoir of the secondary pulse tube.

[0044] S5: Adjust the bidirectional air intake holes 7 and 8 of the primary pulse tube and the secondary pulse tube hot end heat exchanger 9 and the secondary pulse tube hot end heat exchanger 10 between the air outlet of 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 intake regulation.

[0045] S6: Control the separation type gas distribution valve 2 to rotate to the return gas state, so that the compressed helium gas 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.

[0046] S7: After passing through the first-stage regenerator 13 and the second-stage regenerator 16, the helium gas returns to the return port of the compressor 1 via the separate gas distribution valve 2 to complete the cycle.

[0047] Furthermore, each bidirectional intake pulse tube refrigerator can be individually phase-adjusted to achieve its optimal performance.

[0048] This invention integrates two or more bidirectional air-intake pulse tube refrigerators onto a single flange, sharing a valve-separated gas distribution valve. This allows the bidirectional air-intake pulse tube refrigerator system to achieve a greater cooling capacity while avoiding the reduced regenerator efficiency caused by using larger regenerators and pulse tubes in a single bidirectional air-intake pulse tube refrigerator. Furthermore, the valve-separated parallel structure of the bidirectional air-intake pulse tube refrigerators uses the same gas distribution structure for both intake and return, resulting in a symmetrical gas path structure for multiple refrigerators, effectively suppressing vibration. Moreover, each bidirectional air-intake pulse tube refrigerator can include regenerators and heat exchangers with different structures, thereby providing different combinations of cooling capacities to improve the refrigerator's applicability to various applications and needs. Finally, each bidirectional air-intake pulse tube refrigerator can be individually phase-adjusted to achieve its optimal performance.

[0049] The present invention has provided a detailed description of a valve-separated parallel structure pulse tube refrigerator. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of the present invention. For those skilled in the art, the technical solutions of the present invention are not limited to the solutions defined in the specific embodiments. All technical solutions formed by other modifications that can be obviously implemented based on ordinary technical knowledge in the art are within the protection scope of the present invention.

Claims

1. A valve-separated parallel structure bidirectional intake pulse tube refrigerator, comprising a compressor, a separate gas distribution valve, and two or more bidirectional intake pulse tube refrigerators, characterized in that: Two or more pulse tube refrigerators are integrated and connected on the same flange in parallel, and share a separate gas distribution valve and compressor. The compressor intake and return are executed by the same separate gas distribution valve. At the same time, two or more bidirectional intake pulse tube refrigerators are arranged symmetrically in the radial direction around the inlet and outlet ports located at the center of the flange, so that the mechanical forces generated by the airflow through the primary and secondary pulse tube gas storage holes and the primary and secondary bidirectional intake holes of each pulse tube refrigerator cancel each other out.

2. The valve-separated parallel structure bidirectional air-intake pulse tube refrigerator as described in claim 1, wherein each bidirectional air-intake pulse tube refrigerator integrated on the same flange includes a primary pulse tube gas reservoir, a secondary pulse tube gas reservoir, a primary pulse tube gas reservoir orifice, a secondary pulse tube gas reservoir orifice, a primary pulse tube bidirectional air-intake orifice, a secondary pulse tube bidirectional air-intake orifice, 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, a connection passage between the primary pulse tube and the regenerator, a connection passage between the secondary pulse tube and the regenerator, a secondary pulse tube cold-end heat exchanger, and a secondary cold end.

3. The valve-separated parallel structure bidirectional air intake pulse tube refrigerator as described in claim 2, wherein each bidirectional air intake pulse tube refrigerator includes a regenerator and a heat exchanger with different structures.

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

5. The valve-separated parallel structure bidirectional air intake pulse tube refrigerator as described in claim 2 or 3, wherein two or more bidirectional air intake pulse tube refrigerators are each equipped with a primary and secondary cold end copper block.

6. The valve-separated parallel structure bidirectional air intake pulse tube refrigerator as described in claim 2 or 3, wherein each bidirectional air intake pulse tube refrigerator is phase-adjusted to achieve its optimal cooling performance.

7. A control method for a valve-separated parallel structure bidirectional intake pulse tube refrigerator as described in claims 2-6, comprising the following steps: S1: Control the compressor to start, sending the compressed high-pressure helium gas into the separate gas distribution valve; S2: Control the separate gas distribution valve to rotate to the intake state, so that the helium gas enters each bidirectional intake pulse tube refrigerator evenly after passing through the junction; S3: After the helium gas enters the first-stage regenerator of each bidirectional intake pulse tube refrigerator and releases heat, its temperature decreases. Part of the cooled helium gas enters the first-stage pulse tube to compress the helium gas in the first-stage pulse tube. The compressed helium gas dissipates heat through the heat exchanger at the hot end of the first-stage pulse tube, and the first-stage phase adjustment is performed by adjusting the opening of the small orifice of the gas reservoir in the first-stage pulse tube; S4: The other part of the cooled helium gas enters the second-stage regenerator for further cooling, and the cooled helium gas enters the second-stage pulse tube for compression. S5: The compressed helium in the secondary pulse tube is cooled by the heat exchanger at the hot end of the secondary pulse tube, and the phase adjustment is performed by adjusting the opening of the gas reservoir orifice in the secondary pulse tube; S6: The bidirectional air intake orifice of the primary pulse tube and the bidirectional air intake orifice of the secondary pulse tube between the compressor outlet and the heat exchanger at the hot end of the primary pulse tube and the heat exchanger at the hot end of the secondary pulse tube are adjusted to achieve bidirectional air intake regulation; S7: The separate gas distribution valve is controlled to rotate to the return gas state, so that the compressed helium in the primary and secondary pulse tubes expands and cools down, thereby reducing the temperature of the cold end of the primary and secondary pulse tubes; S8: After passing through the primary and secondary regenerators, the helium returns to the compressor return gas port through the gas distribution valve to complete the cycle.

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