CN103512258B - Pulse tube refrigerator driven by V-M type thermal compressor in liquid helium temperature zone - Google Patents

Abstract

A VM-type thermal compressor-driven pulse tube refrigerator in the liquid helium temperature zone includes a Stirling pulse tube refrigerator in the liquid nitrogen temperature zone, a VM thermal compressor, a low-temperature side pulse tube refrigerator and a thermal bridge; a low-temperature side refrigerator Valves are installed between the heat exchanger at the hot end and the gas storage; valves are installed between the inlet and outlet of the heat exchanger at the hot end, and the phase adjustment mechanism is composed of the second valve and the gas storage of the refrigerator on the low temperature side; the heat exchanger at the cold end of the Stirling refrigerator and the hot compressor They are in contact with the heat bridge respectively, and the cold end heat exchanger of the low-temperature side refrigerator communicates with the intermediate heat exchanger, and the intermediate heat exchanger of the low-temperature side refrigerator is pre-cooled through the thermal bridge; at the cold end heat exchanger of the thermal compressor, a part of the gas The pressure fluctuation enters the thermal buffer tube of the thermal compressor, and the other part enters the intermediate heat exchanger, and the outlet of the regenerator of the refrigerator on the low temperature side and the heat exchanger at the cold end are cooled by the liquid helium temperature zone; the Stirling refrigerator is the cold source; The temperature gradient between the compressor room temperature and the cold source produces pressure fluctuations; the low-temperature side refrigerator is driven by pressure waves, and finally reaches the liquid helium temperature zone.

Description

A pulse tube refrigerator driven by a V-M thermal compressor in the liquid helium temperature zone

technical field

The invention belongs to the technical field of cryogenic refrigerators, in particular to a pulse tube refrigerator driven by a V-M thermal compressor in the liquid helium temperature zone of the pulse tube refrigerator driven by a thermal compressor.

Background technique

With the rapid development of modern information technology, space technology, superconducting electronics, infrared detection, low-temperature biomedicine and other industries, especially the popularization and application of low-temperature electronic devices and low-temperature superconducting magnets in various fields, it has promoted the use of direct cooling devices. Or the development of a small liquid helium temperature zone refrigerator for the device.

At present, the small cryogenic refrigerators in the liquid helium temperature zone are mainly G-M refrigerators or G-M pulse tube refrigerators (what is the difference between the two?). They use an oil compressor to cooperate with high and low pressure switching valves to provide pressure waves with a low frequency and high pressure ratio. The gas on the cooling side undergoes a thermal process of compression and expansion, thereby producing a cooling effect. The frequency is usually several hertz; the oil compressor needs to be equipped with an oil separator, etc. The equipment and system are bulky and require regular maintenance, so the service life is difficult to guarantee. At the same time, the gas flows through the high and low pressure switching valve, resulting in pressure drop loss, so the thermal efficiency is low. The Stirling-type refrigerator is driven by a valveless compressor, and its operating frequency is usually above 30Hz. Because the form of cold storage packing in the low-temperature temperature zone is not suitable for high-frequency operation, the existing Stirling-type system that can realize the liquid helium temperature zone The thermal efficiency is much lower than that of the G-M type refrigerator.

Contents of the invention

The purpose of the present invention is to solve the defects of large volume, low efficiency and large vibration of the small-scale low-temperature refrigerator in the liquid helium temperature zone in the prior art, and provide a pulse tube refrigerator driven by a V-M thermal compressor working in the liquid helium temperature zone ; It utilizes the pressure fluctuation generated by the temperature difference between the hot and cold ends to drive the pulse tube refrigerator to obtain low temperature; it has the characteristics of compact structure, high efficiency and long life.

Technical scheme of the present invention is as follows:

The pulse tube refrigerator driven by the V-M type thermal compressor in the liquid helium temperature zone provided by the present invention includes: a Stirling type pulse tube refrigerator in the liquid nitrogen temperature zone, a V-M type thermal compressor and a low temperature side pulse tube refrigerator and thermal bridge;

The Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone is composed of a pressure wave generator, a first hot end heat exchanger, a first regenerator, a first cold end heat exchanger, and a first pulse tube , the first pulse tube hot end heat exchanger, the inertial tube and the first gas storage;

The V-M type thermal compressor is composed of a drive motor, a second hot end heat exchanger, a second regenerator, a second cold end heat exchanger, a thermal buffer tube and a thermal buffer tube hot end heat exchanger connected in sequence; The heat exchanger at the hot end of the thermal buffer tube communicates with the upper space of the piston through a connecting tube;

The pulse tube refrigerator at the low temperature side is composed of an intermediate heat exchanger, a third regenerator, a fourth regenerator, a heat exchanger at the cold end at the low temperature end, a second pulse tube, and a heat exchange at the hot end of the second pulse tube. device, the first valve, the second valve and the second gas storage;

A first valve is installed on the connecting pipeline between the second pulse tube hot end heat exchanger and the second gas storage; the connection between the second pulse tube hot end heat exchanger outlet and the second hot end heat exchanger inlet A second valve is installed on the connecting pipeline between them, and the first valve, the second valve and the second gas store together form the first phase adjustment mechanism;

The first cold-end heat exchanger of the Stirling pulse tube refrigerator in the liquid nitrogen temperature zone and the second cold-end heat exchanger of the V-M thermal compressor are respectively in contact with the heat bridge, and the first The second cold end heat exchanger communicates with the intermediate heat exchanger of the low temperature side pulse tube refrigerator and precools the intermediate heat exchanger of the low temperature pulse tube refrigerator through a thermal bridge; at the second cold end heat exchanger, Part of the gas pressure fluctuations enters the heat buffer tube, and the other part enters the intermediate heat exchanger, and the outlet end of the fourth regenerator and the cold end heat exchanger at the low temperature end are cooled by the liquid helium temperature zone.

The pulse tube refrigerator on the low temperature side adopts a two-stage pulse tube structure: the outlet end of the third regenerator is connected to the third pulse tube, the third pulse tube hot end heat exchanger and the third gas storage in sequence, The fourth valve is installed on the connecting pipeline between the third gas storage and the third pulse tube hot end heat exchanger; the connection between the outlet of the second hot end heat exchanger and the inlet of the third pulse tube hot end heat exchanger A third valve is installed on the pipeline; the third valve, the fourth valve and the third gas store together form the second phase adjustment mechanism.

The first phase modulation mechanism is replaced by a first linear motor.

The second phase modulation mechanism is replaced by a second linear motor.

There are two types of Stirling pulse tube refrigerators in the liquid nitrogen temperature zone:

The first type is: a U-shaped liquid nitrogen temperature zone Stirling pulse tube refrigerator in which the first pulse tube and the first regenerator are placed side by side;

The second type is: a coaxial liquid nitrogen temperature zone Stirling pulse tube refrigerator in which the first pulse tube is located in the first regenerator, and the first regenerator is in the shape of a ring.

The fourth regenerator 18 in the low-temperature side pulse tube refrigerator uses magnetic materials as fillers.

The Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone uses He ⁴ as the gas working medium; the VM-type thermal compressor and the low-temperature side pulse tube refrigerator use He ³ or He ⁴ as the gas working medium.

The pulse tube refrigerator driven by the V-M type thermal compressor in the liquid helium temperature zone of the present invention has the following advantages:

Compared with the traditional liquid helium temperature zone refrigerator, the invention utilizes the V-M type thermal compressor, which can overcome the shortcomings of the electric-driven mechanical compressor, utilizes the temperature difference to generate pressure fluctuations, and fully utilizes the advantages of the compressor such as low operating frequency and compact structure. , the whole system adopts a valve-free and oil-free compressor, which improves reliability and greatly reduces volume; in addition, the core component is a reversible Stirling cycle, which can achieve higher system efficiency than traditional refrigerators; in addition, the low-temperature Moving parts such as ejectors are eliminated on the side, and structures such as pulse tubes are used to isolate low temperature and room temperature. The reliability and life are greatly improved, and the vibration transmitted to the cold head load is reduced; it has the potential to ensure continuous operation for tens of thousands of hours.

Description of drawings

Fig. 1 is a kind of structure diagram of embodiment 1 of single-stage pulse tube refrigerator driven by V-M type thermal compressor;

Fig. 2 is a schematic structural view of Embodiment 2 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor;

Fig. 3 is a schematic structural view of Embodiment 3 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor;

Fig. 4 is a schematic structural view of Embodiment 4 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor;

Fig. 5 is a schematic structural view of Embodiment 5 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor;

Fig. 6 is a schematic structural view of Embodiment 6 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor;

Fig. 7 is a schematic structural diagram of Embodiment 7 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor;

Fig. 8 is a schematic structural diagram of Embodiment 8 of a single-stage pulse tube refrigerator driven by a V-M type thermal compressor.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic structural view of a V-M type thermal compressor driving a single-stage pulse tube refrigerator (embodiment 1) of the present invention; Fig. 2 is a schematic diagram of a V-M type thermal compressor driving a single-stage pulse tube refrigerator (embodiment 2) of the present invention Schematic diagram of the structure; Fig. 3 is a schematic diagram of the structure of a V-M type thermal compressor driven single-stage pulse tube refrigerator (embodiment 3) of the present invention; Fig. 4 is a V-M type thermal compressor driven single-stage pulse tube refrigerator of the present invention (implementation Example 4) Schematic diagram of the structure; Fig. 5 is a schematic diagram of the structure of a V-M type thermal compressor driving a single-stage pulse tube refrigerator (embodiment 5) of the present invention; Fig. 6 is a V-M type thermal compressor driving a single-stage pulse tube of the present invention Schematic diagram of the structure of the refrigerator (embodiment 6); Fig. 7 is a schematic diagram of the structure of a single-stage pulse tube refrigerator driven by a V-M thermal compressor of the present invention (embodiment 7); Fig. 8 is a V-M thermal compressor of the present invention Schematic diagram of the structure of a driving single-stage pulse tube refrigerator (embodiment 8); it can be seen from the figure that the pulse tube refrigerator driven by a V-M thermal compressor in the liquid helium temperature zone of the present invention includes: Stirling in the liquid nitrogen temperature zone Type pulse tube refrigerator, V-M type thermal compressor and low temperature side pulse tube refrigerator and thermal bridge 15;

The Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone is composed of a pressure wave generator 1, a first hot-end heat exchanger 2, a first regenerator 3, a first cold-end heat exchanger 4, The first pulse tube 5, the first pulse tube hot end heat exchanger 6, the inertia tube 7 and the first gas storage 8;

The V-M type thermal compressor is composed of a driving motor 9, a second hot end heat exchanger 10, a second regenerator 11, a second cold end heat exchanger 12, a thermal buffer pipe 13 and a thermal buffer pipe hot end connected in sequence. The heat exchanger 14 is composed; wherein the heat buffer tube hot end heat exchanger 14 communicates with the upper space of the piston 9 through a connecting pipe;

The pulse tube refrigerator on the low temperature side is composed of an intermediate heat exchanger 16, a third regenerator 17, a fourth regenerator 18, a low temperature end cold end heat exchanger 19, a second pulse tube 20, and a second pulse tube refrigerator connected in sequence. Tube hot end heat exchanger 21, first valve 22, second valve 23 and second gas storage 24;

A first valve 22 is installed on the connecting pipeline between the second pulse tube hot end heat exchanger 21 and the second gas storehouse 24; the outlet of the second pulse tube hot end heat exchanger 21 is exchanged with the second hot end heat exchanger A second valve 23 is installed on the connecting pipeline between the inlets of the heater 10, and the first valve 22, the second valve 23 and the second gas reservoir 24 together form the first phase adjustment mechanism;

The first cold end heat exchanger 4 of the Stirling pulse tube refrigerator in the liquid nitrogen temperature zone and the second cold end heat exchanger 12 of the V-M type thermal compressor are respectively in contact with the thermal bridge 15, so The second cold end heat exchanger 12 described above communicates with the intermediate heat exchanger 16 of the low temperature side pulse tube refrigerator and passes through the thermal bridge 15 to precool the intermediate heat exchanger 16 of the low temperature pulse tube refrigerator; At the cold end heat exchanger 12, a part of the gas pressure fluctuation enters the thermal buffer pipe 13, and the other part enters the intermediate heat exchanger 16, and the liquid helium temperature zone is obtained at the outlet end of the fourth regenerator 18 and the cold end heat exchanger 19 at the low temperature end. Refrigeration.

The pulse tube refrigerator on the low temperature side adopts a two-stage pulse tube structure: the outlet end of the third regenerator 17 is connected to the third pulse tube 26, the third pulse tube hot end heat exchanger 27 and the third gas storage in sequence 28. Install a fourth valve 30 on the connecting pipeline between the third gas storage 28 and the third pulse tube hot end heat exchanger 27; connect the outlet of the second hot end heat exchanger 10 to the third pulse tube hot end The connecting pipeline between the inlets of the heat exchangers 27 is equipped with a third valve 29; the third valve 29, the fourth valve 30 and the third gas reservoir 28 together form the second phase adjustment mechanism.

The first phase modulation mechanism is replaced by a first linear motor 25 .

The second phase modulation mechanism is replaced by a second linear motor 31 .

There are two types of Stirling pulse tube refrigerators in the liquid nitrogen temperature zone:

The first type is: a U-shaped liquid nitrogen temperature zone Stirling pulse tube refrigerator in which the first pulse tube 5 and the first regenerator 3 are placed side by side;

The second type is: a coaxial liquid nitrogen temperature zone Stirling pulse tube refrigerator with the first pulse tube 5 located in the first regenerator 3, and the first regenerator 3 is in the shape of a ring.

The fourth regenerator 18 in the low-temperature side pulse tube refrigerator uses magnetic materials as fillers. The Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone uses He ⁴ as the gas working medium; the VM-type thermal compressor and the low-temperature side pulse tube refrigerator use He ³ or He ⁴ as the gas working medium.

Example 1

A typical structure of a V-M thermal compressor-driven pulse tube refrigerator is shown in Figure 1. The pulse tube refrigerator driven by a V-M thermal compressor in the liquid helium temperature zone of this embodiment includes: a liquid nitrogen temperature zone. Tring type pulse tube refrigerator, V-M type thermal compressor and low temperature side pulse tube refrigerator and thermal bridge 15;

The Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone consists of a pressure wave generator 1, a first hot-end heat exchanger 2, a first regenerator 3, a first cold-end heat exchanger 4, and a first pulse tube 5, the first pulse tube hot end heat exchanger 6, the inertia tube 7 and the first gas storage 8;

The V-M type thermal compressor is composed of a driving motor 9, a second hot-end heat exchanger 10, a second regenerator 11, a second cold-end heat exchanger 12, a heat buffer tube 13 and a heat exchange at the hot end of the heat buffer tube connected in sequence. device 14; wherein said thermal buffer tube hot end heat exchanger 14 communicates with the upper space of the piston 9 through a connecting pipe;

The pulse tube refrigerator on the low temperature side is composed of an intermediate heat exchanger 16, a third regenerator 17, a fourth regenerator 18, a low temperature end cold end heat exchanger 19, a second pulse tube 20, and a second pulse tube heat exchanger connected in sequence. End heat exchanger 21, first valve 22, second valve 23 and second gas storage 24;

A first valve 22 is installed on the connecting pipeline between the second pulse tube hot end heat exchanger 21 and the second gas storehouse 24; the outlet of the second pulse tube hot end heat exchanger 21 and the inlet of the second hot end heat exchanger 10 A second valve 23 is installed on the connecting pipeline between them, and the first valve 22, the second valve 23 and the second gas storehouse 24 together form the first phase adjustment mechanism;

The first cold-end heat exchanger 4 of the Stirling pulse tube refrigerator in the liquid nitrogen temperature zone and the second cold-end heat exchanger 12 of the V-M type thermal compressor are respectively in contact with the heat bridge 15, and the second cold-end heat exchanger The heat exchanger 12 communicates with the intermediate heat exchanger 16 of the low-temperature side pulse tube refrigerator and passes through the thermal bridge 15 to precool the intermediate heat exchanger 16 of the low-temperature pulse tube refrigerator; at the second cold end heat exchanger 12 A part of the gas pressure fluctuations enters the thermal buffer pipe 13, and the other part enters the intermediate heat exchanger 16, and the outlet end of the fourth regenerator 18 and the cold end heat exchanger 19 at the low temperature end are cooled by the liquid helium temperature zone.

The pressure wave generator 1 in the Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone generates pressure fluctuations, which pushes He ⁴ to reciprocate, and produces a refrigeration effect in the first regenerator 3, thereby passing through the first cold end heat exchanger 4. A certain cooling capacity is generated in the liquid nitrogen temperature zone, and the cooling capacity is transferred to the second cold-end heat exchanger 14 in the thermal compressor through the thermal bridge 15 as a cold source of the thermal compressor. The second hot-end heat exchanger 10 in the thermal compressor works at room temperature, or works at a high temperature by means of heating; the thermal compressor relies on the temperature difference between the second hot-end heat exchanger 10 and the second cold-end heat exchanger 14 to work, Under the action of the driving motor 4, He ⁴ or He ³ is pushed to reciprocate and undergo a VM-type thermodynamic cycle, and the thermal energy is converted into kinetic energy of the gas in the second regenerator 11, thereby generating large pressure fluctuations;

The refrigerating capacity generated by the Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone is also used as the cold source of the pulse tube refrigerator on the low temperature side; the gas pressure fluctuation generated by the thermal compressor is used as the driving source, and passes through the third regenerator 17 and the fourth The regenerator 17 pumps the heat from the cold end heat exchanger 19 on the low temperature side to the intermediate heat exchanger 16, and then reaches the liquid helium temperature zone;

In the liquid helium temperature zone, the volumetric specific heat capacity of helium increases, and the heat capacity of ordinary fillers decreases. Therefore, magnetic heat storage materials are used in the fourth regenerator 18 .

The Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone shown in Figure 1 adopts a U-shaped structure, the first pulse tube 5 is placed in parallel with the first regenerator 3, and its hot end adopts the method of inertial tube gas filling storage for phase adjustment ;

The pulse tube refrigerator on the low temperature side adopts the method of valve gas filling storage for phase modulation, and the second valve 22 connects the second pulse tube hot end heat exchanger 21 and the entrance of the intermediate heat exchanger 16 to form a two-way air intake mechanism, and the second valve 23 and the second gas storage 24 jointly form a phase adjustment mechanism, which is used to adjust the relationship between pressure fluctuation and gas velocity, and form a suitable pressure velocity boundary condition.

Example 2

As shown in Figure 2, the structure of this embodiment is basically similar to that of Embodiment 1, but the low-temperature side pulse tube refrigerator has a two-stage structure, which can obtain a lower refrigeration temperature; at the outlet of the third regenerator 17 connected to the third pulse tube 26, the third pulse tube hot end heat exchanger 27 and the third gas storage 28 in turn, and installed on the connecting pipeline between the third gas storage 28 and the third pulse tube hot end heat exchanger 27 The fourth valve 30; a third valve 29 is installed on the connecting pipeline between the outlet of the second hot end heat exchanger 10 and the inlet of the third pulse tube hot end heat exchanger 27; the third valve 29, the third valve The four valves 30 and the third gas bank 28 together form the second phase adjustment mechanism.

Example 3

As shown in Figure 3, the structure of this embodiment is basically similar to that of Embodiment 1, but the phase modulation mechanism of the pulse tube refrigerator on the low temperature side is changed, the valve and the gas storage are removed, and the first linear motor 25 is used for phase modulation. The first linear motor 25 is installed on the outside of the second pulse tube hot end heat exchanger 21. The first linear motor 25 is a kind of typical linear compressor, including structures such as coils, movers, springs and pistons. Different combinations of different pressure and velocity boundary conditions can be achieved, so as to obtain a suitable phase and impedance relationship.

Example 4

As shown in Figure 4, the structure of this embodiment is basically similar to that of Embodiment 2. The pulse tube refrigerator on the low temperature side adopts a bipolar structure; The linear motor replaces the valve and the gas storage, and the outer side of the second pulse tube hot end heat exchanger 21 adopts the first linear motor 25 for phase adjustment; the third pulse tube hot end heat exchanger 27 uses the second motor 31 for phase adjustment. Phase, principle is the same as embodiment 3.

Example 5

The basic structure of Embodiment 5 is the same as that of Embodiment 1. The pulse tube refrigerator on the low temperature side has a single-stage structure and adopts valve gas storage for phase adjustment; however, the Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone adopts a coaxial structure, and the first pulse tube 5 is displaced in the middle of the first regenerator 3, and the first regenerator 3 is annular. The specific structure is shown in Figure 5.

Example 6

The basic structure of Embodiment 6 is the same as that of Embodiment 2. The pulse tube refrigerator on the low temperature side has a two-stage structure and uses valve gas storage for phase adjustment; however, the Stirling type pulse tube refrigerator in the liquid nitrogen temperature zone adopts a coaxial structure, and the first pulse tube 5 is displaced in the middle of the first regenerator 3, and the first regenerator 3 is annular; the specific structure is shown in FIG. 6 .

Example 7

The basic structure of Embodiment 5 is the same as that of Embodiment 3. The pulse tube refrigerator on the low temperature side is a single-stage structure and adopts a linear motor for phase modulation; however, the Stirling-type pulse tube refrigerator in the liquid nitrogen temperature zone adopts a coaxial structure, and the first pulse tube 5 The middle of the first regenerator 3 is displaced, and the first regenerator 3 is annular; the specific structure is shown in FIG. 7 .

Example 8

The basic mechanism of embodiment 6 is the same as that of embodiment 4. The pulse tube refrigerator on the low temperature side has a two-stage structure and adopts linear motor phase modulation; however, the Stirling type pulse tube refrigerator in the liquid nitrogen temperature zone adopts a coaxial structure, and the first pulse tube 5 Displacing the middle of the first regenerator 3, the first regenerator 3 is ring-shaped. The specific structure is shown in Figure 8.

Compared with the traditional liquid helium temperature range refrigerator, the pulse tube refrigerator driven by the V-M type thermal compressor in each liquid helium temperature range of the above-mentioned embodiment uses the V-M type thermal compressor to overcome the shortcomings of the electrically driven mechanical compressor, The temperature difference is used to generate pressure fluctuations, making full use of the advantages of the compressor such as low operating frequency and compact structure. The whole system adopts a valve-free and oil-free compressor, which improves reliability and greatly reduces volume; in addition, the core component is a reversible Si The Tring cycle can achieve higher system efficiency than traditional type refrigerators; in addition, the low-temperature side of the present invention eliminates moving parts such as ejectors, and adopts structures such as pulse tubes to isolate low temperature and room temperature, greatly improving reliability and life, and at the same time passing to The vibration of the cold head load is reduced; it has the potential to ensure continuous operation of more than tens of thousands of hours.

Claims (7)

1. a pulse tube refrigerating machine for the V-M type thermocompressor driving of liquid helium region, it comprises: liquid nitrogen temperature Stirling Type Pulse Tube Cryocooler, V-M type thermocompressor and low temperature side pulse tube refrigerating machine and heat bridge;

Described liquid nitrogen temperature Stirling Type Pulse Tube Cryocooler is made up of the pressure wave generator be connected successively, the first hot end heat exchanger, the first regenerator, the first cool end heat exchanger, the first pulse tube, the first pulse tube hot end heat exchanger, inertia tube and the first air reservoir;

Described V-M type thermocompressor is made up of the drive motors be connected successively, the second hot end heat exchanger, the second regenerator, the second cool end heat exchanger, thermal buffer tube and thermal buffer tube hot end heat exchanger; Wherein said thermal buffer tube hot end heat exchanger is communicated with upper piston area space by tube connector;

Described low temperature side pulse tube refrigerating machine is made up of the Intermediate Heat Exchanger be connected successively, the 3rd regenerator, the 4th regenerator, low-temperature end cool end heat exchanger, the second pulse tube, the second pulse tube hot end heat exchanger, the first valve, the second valve and the second air reservoir;

Connecting line between described second pulse tube hot end heat exchanger and the second air reservoir is equipped with the first valve; Connecting line between described second pulse tube hot end heat exchanger outlet and the second hot end heat exchanger entrance is equipped with the second valve, and described first valve, the second valve and the second air reservoir form the first phase modulating mechanism jointly;

First cool end heat exchanger of described liquid nitrogen temperature Stirling Type Pulse Tube Cryocooler contacts with described heat bridge respectively with the second cool end heat exchanger of described V-M type thermocompressor and is connected, and the second described cool end heat exchanger is connected with the Intermediate Heat Exchanger of low temperature side pulse tube refrigerating machine and carries out precooling by heat bridge and to the Intermediate Heat Exchanger of low temperature side pulse tube refrigerating machine; At the second cool end heat exchanger place, a part of gas pressure fluctuation enters thermal buffer tube, and another part enters Intermediate Heat Exchanger, obtains liquid helium region refrigeration at the 4th regenerator port of export and low-temperature end cool end heat exchanger.

2. by the pulse tube refrigerating machine that the V-M type thermocompressor of liquid helium region according to claim 1 drives, it is characterized in that, described low temperature side pulse tube refrigerating machine adopts two-stage pulse tube structure: connect the 3rd pulse tube, the 3rd pulse tube hot end heat exchanger and the 3rd air reservoir successively at the port of export of described 3rd regenerator, the connecting line between the 3rd air reservoir and the 3rd pulse tube hot end heat exchanger is installed the 4th valve; Connecting line between described second hot end heat exchanger outlet and the 3rd pulse tube hot end heat exchanger entrance is equipped with the 3rd valve; Described 3rd valve, the 4th valve and the 3rd air reservoir form the second phase modulating mechanism jointly.

3., by the pulse tube refrigerating machine that the V-M type thermocompressor of liquid helium region according to claim 1 drives, it is characterized in that, described first phase modulating mechanism is substituted by the first linear electric motors.

4., by the pulse tube refrigerating machine that the V-M type thermocompressor of liquid helium region according to claim 2 drives, it is characterized in that, the second described phase modulating mechanism is substituted by the second linear electric motors.

5., by the pulse tube refrigerating machine that the V-M type thermocompressor of liquid helium region according to claim 1 drives, it is characterized in that, described liquid nitrogen temperature Stirling Type Pulse Tube Cryocooler has two kinds of patterns:

The first pattern is: the U-shaped liquid nitrogen temperature Stirling Type Pulse Tube Cryocooler that described first pulse tube and the first regenerator are placed side by side;

The second pattern is: the first pulse tube is positioned at the coaxial type liquid nitrogen temperature Stirling Type Pulse Tube Cryocooler among the first regenerator, this first regenerator shape ringwise.

6. by the pulse tube refrigerating machine that the V-M type thermocompressor of liquid helium region according to claim 1 drives, it is characterized in that, in described low temperature side pulse tube refrigerating machine, the 4th regenerator adopts magnetic material as filler.

7., by the pulse tube refrigerating machine that the V-M type thermocompressor of liquid helium region according to claim 1 drives, it is characterized in that, in the Stirling Type Pulse Tube Cryocooler of described liquid nitrogen temperature, adopt He ⁴as gas working medium; Described V-M type thermocompressor and low temperature side pulse tube refrigerating machine adopt He ³or He ⁴as gas working medium.