阅读说明：本技术 一种间隙式制冷机高效预冷及液化系统 (Efficient precooling and liquefying system of clearance type refrigerating machine ) 是由 曹强 李芃 于 2021-09-17 设计创作，主要内容包括：本发明涉及一种间隙式制冷机高效预冷及液化系统,包括回热式制冷模块和预冷及液化模块；回热式制冷模块包括回热式制冷机单元和直流内部循环单元；回热式制冷机单元包括依次连接的压缩机装置、回热器、冷端换热器、膨胀活塞和内部间隙结构；直流从特定位置引入内部间隙结构,待预冷物料在进口与气缸外壁换热组件处进行预冷,进入到冷料收集组件中。液化系统中物料则在预冷后进入冷端换热管路中被液化,进入至液体收集组件中。与现有技术相比,本发明通过引出与回热内交变流进行换热的直流,与被待预冷物料通过气缸壁进行间壁式换热,可有效降低热阻,从而提高预冷及液化效率。(The invention relates to a high-efficiency precooling and liquefying system of a clearance type refrigerator, which comprises a regenerative refrigerating module and a precooling and liquefying module; the regenerative refrigeration module comprises a regenerative refrigerator unit and a direct-current internal circulation unit; the regenerative refrigerator unit comprises a compressor device, a regenerator, a cold end heat exchanger, an expansion piston and an internal gap structure which are connected in sequence; the direct current is introduced into the internal gap structure from a specific position, and the material to be precooled is precooled at the inlet and the heat exchange assembly of the outer wall of the cylinder and enters the cold material collecting assembly. And the material in the liquefaction system enters a cold end heat exchange pipeline after precooling to be liquefied and enters a liquid collection assembly. Compared with the prior art, the direct current for exchanging heat with the regenerative internal alternating current is led out, and the direct current and the material to be precooled exchange heat in a wall type through the cylinder wall, so that the thermal resistance can be effectively reduced, and the precooling and liquefying efficiency can be improved.)

1. An efficient precooling and liquefying system of a clearance type refrigerator is characterized by comprising a regenerative refrigeration module and a precooling and liquefying module;

the regenerative refrigeration module comprises a regenerative refrigerator unit and a direct-current internal circulation unit;

the regenerative refrigerator unit comprises a compressor device (1), a heat regenerator, a cold end heat exchanger (12), an expansion piston and an internal gap structure which are connected in sequence;

the direct-current internal circulation unit is as follows: the direct current (28) is introduced into the internal gap structure from a specific position, the direct current (28) and the material (23) to be precooled are subjected to partition type heat exchange through a cylinder wall through a gap, the material to be precooled is precooled by using cold energy carried by the direct current (28) in the heat regenerator and then returns to the heat regenerator to complete direct current internal circulation, and the direct current flow is controlled through the direct current control valve (20);

the pre-cooling and liquefying module comprises a material source (21) of a material to be pre-cooled, a feeding control mechanism (22), a feeding and cylinder outer wall heat exchange assembly (23), a cold end heat exchange pipeline (24) and a cold material collecting assembly (25), wherein the material source (21) is pre-cooled at the feeding and cylinder outer wall heat exchange assembly (23) and enters the cold material collecting assembly (25).

2. The efficient precooling and liquefying system of a gap refrigerator according to claim 1, wherein the internal gap structure comprises a gap formed by an expansion piston and a cylinder, a gap formed by multiple layers of channels in a pressure-bearing pipe of the regenerator, and a gap formed by multiple layers of channels in a pulse tube pressure-bearing pipe.

3. The efficient precooling and liquefying system of a gap refrigerator according to claim 1, wherein the position where the direct current (28) is introduced into the internal gap structure is the cold end of the regenerator, or any position between the cold end of the regenerator and the hot end of the regenerator;

the position of the direct current (28) led out from the internal gap structure comprises the hot end of the heat regenerator, and any position between the hot end of the heat regenerator and the cold end of the heat regenerator.

4. The efficient precooling and liquefying system of the gap refrigerator according to claim 3, wherein the direct current (28) is led out from the internal gap structure and then can be led into the heat regenerator, or led into the low-voltage component and then led into the heat regenerator, or driven by the high-voltage component to form a cycle;

the low-pressure component is a low-pressure pipeline or a low-pressure cavity formed by arranging a one-way valve;

the high-pressure component is a high-pressure pipeline or a high-pressure cavity formed by arranging a one-way valve.

5. The efficient precooling and liquefying system of a gap refrigerator according to claim 1, wherein the regenerative refrigerator unit is a refrigerator which uses a regenerator component to realize alternating storage and release of heat, and the regenerative refrigerator unit comprises one of a GM refrigerator, a Solvay refrigerator, a Stirling refrigerator, a VM refrigerator and a pulse tube refrigerator, or a mixed structure form of multiple multi-stage coupling;

the pulse tube refrigerator comprises a GM type pulse tube refrigerator and a Stirling type pulse tube refrigerator.

6. The efficient precooling and liquefying system of the gap refrigerator according to claim 5, wherein the regenerative refrigeration module is of a built-in structure or an external structure;

in the built-in structure of the heat regenerator, the heat regenerator is built in the expansion piston;

in the external heat regenerator structure, the expansion piston and the heat regenerator are arranged in a split mode;

the regenerative refrigeration module comprises a single-stage structure and a multi-stage coupling structure, wherein the multi-stage coupling structure comprises a multi-stage thermal coupling structure, a multi-stage air coupling structure and a thermal coupling and air coupling mixed structure.

7. The efficient precooling and liquefying system of the gap type refrigerating machine as claimed in claim 1, wherein the structural form of the feeding and cylinder outer wall heat exchange assembly (23) comprises a pipeline for heat exchange with the cylinder wall through heat conduction and a structure for heat convection with the cylinder wall.

8. The efficient precooling and liquefying system of a gap refrigerator according to claim 1, wherein the average working pressure in the regenerative refrigeration module is 1 to 500 times atmospheric pressure.

9. The efficient precooling and liquefying system of the gap type refrigerating machine according to claim 1, wherein the precooling and liquefying module comprises a precooling function, a liquefying function or a combination of the precooling function and the liquefying function, and the liquefying amount of the material to be precooled accounts for 0-100% of the total amount of the material to be precooled;

the material to be precooled comprises gas, liquid or solid, or the mixture of any two or three of three material phases of gas, liquid and solid;

the material to be precooled comprises a pure substance and a mixture consisting of a plurality of substances.

10. The efficient precooling and liquefying system of the gap refrigerator according to claim 1, wherein the feeding quantity of the precooling and liquefying modules meets the condition that the heat capacity of the material is matched with the heat capacity of the direct current at each temperature zone to be the maximum value, and the feeding quantity ranges between the maximum value and zero;

under the working condition that the feeding quantity is zero, the efficient precooling and liquefying system of the gap type refrigerating machine comprises a regenerative refrigerating module and no precooling and liquefying module, or simultaneously reserves two conditions of the regenerative refrigerating module and the precooling and liquefying module.

Technical Field

The invention relates to the technical field of refrigeration, in particular to a precooling and liquefying system of a regenerative refrigerator.

Background

The regenerative refrigerator is a refrigerating technology in an alternating flow mode, realizes periodic heat storage and release between a gas working medium and regenerative filler by utilizing a heat regenerator, and generates a refrigerating effect by utilizing expansion of gas. The regenerator generally has a large specific surface area per unit volume, and the structural form comprises a wire mesh, a pill filler, a gap type and the like.

The direct current is the air flow quality of forward flow and reverse flow of a certain section in a period is unequal, and the net mass flow rate flowing along one direction is generated. Direct current is also known as direct current circulating mass flow.

The gap is a space formed near the wall of the pressure vessel, and is generally annular in structure, and the radial length is small relative to the diameter. The pressure-bearing container is internally used for bearing the working pressure of the working medium, the outside of the pressure-bearing container is ambient pressure or vacuum, and the pressure-bearing container comprises a cylinder in an expansion piston type structure and a pressure-bearing pipe in a pulse tube refrigerator.

The regenerative low-temperature refrigerator has the advantages of high reliability, simple structure, high efficiency and the like, and is widely applied to low-temperature technologies such as gas liquefaction, superconducting cooling and the like.

The ideal regenerative cryocooler does not have a direct current during operation. With the introduction of the two-way air inlet structure in the pulse tube refrigerator, a closed loop formed by the two-way air inlet valve, the regenerator and the pulse tube is formed. This loop induces a direct current flow, which was also referred to as a Gedeon direct current since it was first formally proposed by Gedeon and theorized. A series of theories and experiments later show that direct current with a certain flow rate has the potential of improving the refrigerating performance of the pulse tube refrigerator. In 1997, chen national bang et al introduced a direct current into a two-stage pulse tube refrigerator, which reduced the temperature in the middle of the pulse tube, reduced the loss, and improved the refrigeration efficiency. In 1998, Wangcheng discovered that a certain direct current can significantly improve the refrigeration performance of a GM refrigerator by a method of combining numerical simulation and experiments, and proved that the liquefaction efficiency can be improved by coiling helium to be liquefied outside a regenerator of a pulse tube refrigerator.

In 2019, Cao Qiang proposes that the direct current is introduced into a heat regenerator of a refrigeration cycle to reduce the actual gas loss, and discloses a working mechanism of adding the direct current into the heat regenerator with an obvious actual gas effect on the basis of thermodynamic analysis, so as to obtain a theoretical expression of the direct current quantity in the heat regenerator and a theoretical value of COP (coefficient of performance) of the heat regenerator after the direct current is added. The results show that the heat regenerator with direct current can obviously improve COP.

Low temperature gas liquefaction is an important industrial application of low temperature engineering, and a great deal of demands are made on working media such as air, natural gas, hydrogen, helium and the like in industry. The improvement of the liquefaction efficiency can obviously reduce the equipment cost and the energy consumption.

Cryogenic gaseous storage is also an important application in the industry, particularly for hydrogen where the liquefaction temperature is very low. At present, a scheme that the filling pressure reaches 30MPa and the operating temperature range reaches 33K to room temperature exists in a hydrogen energy automobile. Correspondingly, the gaseous precooling also has a large cold requirement.

The pre-cooling of the low-temperature liquid comprises obtaining low-temperature liquid such as low-temperature ethanol and the like, and realizing the functions of a thermostat or cooling. The pre-cooling of the cryogenic solids includes cold accumulators for cold storage and the like.

The regenerative refrigerator adopting the expansion piston has high efficiency and is widely applied to small and medium precooling and liquefying systems. At present, the precooling flow channel is coiled on the outer side of the pipe wall of the heat regenerator or precooled in a convection mode, and the heat exchange thermal resistance is large. And along with the increase of the cooling capacity, the size of the heat regenerator structure is increased, and the radial thermal resistance is also increased. These result in low efficiency of pre-cooling and liquefaction and high cost per unit volume of pre-cooling and liquefaction.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide an efficient precooling and liquefying system of a clearance type refrigerator, which adopts a direct-current efficient precooling and liquefying system of a regenerative refrigerator, and the cold end and the hot end of a heat regenerator are communicated through the clearance formed by an expansion piston clearance or an increased channel to form stable direct-current circulation, so that the direct-current circulation absorbs cold energy in the heat regenerator, flows through the clearance, exchanges heat with a precooling and liquefying module through the cylinder wall, precools a material to be precooled, and returns to the hot end of the heat regenerator to finish circulation.

The purpose of the invention can be realized by the following technical scheme:

the application aims to protect an efficient precooling and liquefying system of a gap type refrigerator, which comprises a regenerative refrigerating module and a liquefying module;

the regenerative refrigeration module comprises a regenerative refrigerator unit and a direct-current internal circulation unit;

the regenerative refrigerator unit comprises a compressor device, a heat regenerator, a cold end heat exchanger, an expansion piston and an internal gap structure which are sequentially connected; for the pulse tube refrigerator, an expansion piston and an internal clearance structure are not arranged, and a pulse tube, a pulse tube hot end heat exchanger and a phase modulation mechanism are sequentially connected after passing through a cold end heat exchanger.

The direct-current internal circulation unit is as follows: the direct current is introduced into the internal gap structure from a specific position, the direct current and the material to be precooled are subjected to partition type heat exchange through the cylinder wall through the gap, the material to be precooled is precooled by using cold energy carried by the direct current in the heat regenerator and then returns to the heat regenerator, the direct current internal circulation is completed, and the circulating flow is controlled by the direct current control valve;

the pre-cooling and liquefying module comprises a material source, a feeding control mechanism, a feeding and cylinder outer wall heat exchange assembly, a cold end heat exchange pipeline and a cold material collecting assembly which are sequentially communicated, and pre-cooling is carried out on the feeding and cylinder outer wall heat exchange assembly in the material source and enters the cold material collecting assembly. The liquefaction module also comprises a device for liquefying materials in the cold end heat exchange pipeline.

Further, the internal clearance structure comprises a clearance formed by an expansion piston and a cylinder, a clearance formed by multiple layers of channels in a pressure pipe of the regenerator, and a clearance formed by multiple layers of channels in a pulse tube pressure pipe. Multilayer refers to two, three or more layers.

The locations where the internal gap structure is formed by multiple layers of channels include regenerator and pulse tube sections, or both regenerator and pulse tube sections are used simultaneously.

Further, the position of the internal gap structure introduced by the direct current is the cold end of the heat regenerator, or any position between the cold end of the heat regenerator and the hot end of the heat regenerator;

the position led out from the internal gap structure by the direct current comprises the hot end of the heat regenerator and any position between the hot end of the heat regenerator and the cold end of the heat regenerator. The direct current exit point is at a higher temperature than the direct current entry point.

Furthermore, the direct current can be directly led into the heat regenerator after being led out from the internal gap structure, or led into the heat regenerator after being led into the low-voltage component, or driven by the high-voltage component to form circulation;

the low-pressure assembly is a low-pressure pipeline with a valve compressor (GM type) or a low-pressure cavity formed by arranging a one-way valve in a valveless compressor (Stirling type) and the valve compressor; the low-pressure pipeline is a structure before compression, such as a low-pressure distribution pipe, a low-pressure gas storage tank and the like; the low-pressure cavity formed by the check valve comprises a low-pressure air reservoir and a low-pressure check valve, wherein the low-pressure air reservoir and the low-pressure check valve are arranged along the direct-current moving direction, and the low-pressure air reservoir is arranged at the downstream of the direct-current control valve.

The high-pressure assembly is a high-pressure pipeline with a valve compressor (GM type) or a high-pressure cavity formed by arranging a one-way valve in a valveless compressor (Stirling type) and the valve compressor. The pipeline to be compressed is a compressed high-pressure distribution pipe, a compressed low-pressure air storage tank and the like;

further, the regenerative refrigerator unit is: the combined structure of the Gifford-Membranon (GM) refrigerator with the expansion piston mechanism, the Solvey refrigerator, the Stirling refrigerator, the Viller Miller (VM) refrigerator, and the pulse tube refrigerator without the expansion piston mechanism can also be a mixed structure form in which the above structure forms are coupled in multiple stages. The pulse tube refrigerator comprises a GM type pulse tube refrigerator and a Stirling type pulse tube refrigerator.

Pulse tube refrigerators may form an internal gap structure in the regenerator section or pulse tube section by forming a multilayer channel. The refrigerator with expansion piston mechanism can also be formed by a multi-layer channel in the gap structure of the regenerator part.

Furthermore, the pulse tube refrigeration module further comprises a cold end connecting tube, a pulse tube cold end heat exchanger, a pulse tube hot end heat exchanger and a phase modulation mechanism which are connected in sequence, wherein the cold end connecting tube is led out from the cold end heat exchanger.

Furthermore, the regenerative refrigeration module is of a built-in structure of a heat regenerator or an external structure of the heat regenerator;

in the built-in structure of the heat regenerator, the heat regenerator is built in the expansion piston and moves along with the expansion piston;

in the external heat regenerator structure, the expansion piston and the heat regenerator are arranged in a split mode, and the expansion piston moves while the heat regenerator is generally fixed;

the regenerative refrigeration module comprises a single-stage structure and a multi-stage coupling structure, wherein the multi-stage coupling structure comprises a multi-stage thermal coupling structure, a multi-stage air coupling structure and a thermal coupling and air coupling mixed structure. The multilevel structure can realize lower refrigeration temperature and provide the cold energy of a plurality of temperature areas. The multiple stages include two stages and more than two stages.

Further, the structural form of the feeding material and cylinder outer wall heat exchange assembly comprises a feeding pipeline which exchanges heat with the cylinder wall through heat conduction, for example, a feeding pipe is coiled to be in thermal contact with the cylinder wall, and the feeding material and the cylinder wall exchange heat in a convection mode.

Further, the feeding control mechanism is a pressure control valve, a capillary tube, a nozzle or a resistance element formed by porous media.

Further, the average working pressure in the regenerative refrigeration module is generally greater than 1 time of atmospheric pressure, which is 1-500 times of atmospheric pressure (i.e. 0.1-50MPa), and the working pressure of the pre-cooling and liquefying module is generally different from the pressure in the regenerative refrigeration module, which is usually close to atmospheric pressure, but high pressure can be achieved in the high-pressure low-temperature gas storage system, and therefore, 0.01-2000 times of atmospheric pressure (i.e. 0.001-200MPa) can be included.

Further, the pre-cooling and liquefying module comprises a pre-cooling function, a liquefying function and a combination of the pre-cooling function and the liquefying function, and the liquefying amount of the material to be pre-cooled accounts for 0% -100% of the total amount of the material to be pre-cooled.

The material to be precooled comprises gas, liquid or solid and the mixture of any two or three of gas, liquid and solid phases.

The material to be precooled comprises a pure substance and a mixture consisting of a plurality of substances.

Furthermore, the direct-current internal circulation unit of the regenerative refrigeration module comprises a single direct current and a plurality of direct currents led out from the refrigerator. For example, in a structure in which the heat regenerator and the expansion piston are placed in parallel, two direct currents can be respectively formed at the heat regenerator and the expansion piston, two direct currents can be respectively formed through the heat regenerator and the pulse tube in the pulse tube refrigerator, and multiple direct currents can also be formed according to temperature sections; the positions of the precooling and liquefying module for dividing wall type heat exchange through the cylinder wall comprise a single position and a plurality of positions, for example, two heat exchanges can be formed at the positions of a heat regenerator cylinder and an expansion piston cylinder in a structure that the heat regenerator and the expansion piston are arranged in parallel, two heat exchanges can be respectively formed through the heat regenerator and a pulse tube in a pulse tube refrigerator, and the working media to be precooled and liquefied at the plurality of positions are the same working media or a plurality of different working media.

Compared with the prior art, the invention has the following technical advantages:

1) the invention adopts a high-efficiency precooling and liquefying system of a direct-current regenerative refrigerator, so that direct current absorbs cold energy in the heat regenerator, flows through the gap of an expansion piston, exchanges heat with a precooling and liquefying module through the cylinder wall, precools a material to be precooled, and returns to the hot end of the heat regenerator to complete circulation. A traditional refrigerator precools through the outer wall of a heat regenerator, and due to the fact that an air gap exists between the heat regenerator and an air cylinder, a large air gap thermal resistance exists between a material to be precooled and the heat regenerator for heat exchange. Along with the increase of the cooling capacity, the size of the heat regenerator structure is increased, and the radial thermal resistance is also increased. The led direct current is closely contacted with the regenerative filler and the alternating current, so that almost no heat exchange temperature difference is achieved, and the thermal resistance can be effectively reduced.

2) The heat regenerator can absorb a certain amount of direct flow enthalpy flow, and the increase of cold end enthalpy flow caused by the direct flow with proper size is far smaller than the total enthalpy flow absorbed by the heat regenerator, so that the extracted direct flow is fully utilized, and the precooling and liquefying capabilities of a refrigerating machine can be improved. Particularly, in a working medium area close to a critical temperature area, a maximum allowed direct current amount exists due to an actual gas effect, and in the direct current range, the COP of the actual heat regenerator is slightly reduced due to the influence of direct current.

3) The low-temperature liquid generated by the efficient precooling and liquefying system of the direct-current regenerative refrigerator can be used as a constant-temperature cold source, and the low-temperature requirement of stable constant temperature is met.

4) The small-sized low-temperature refrigerating machine with the structural form can obviously improve the liquefaction efficiency, is small in equipment and movable, can be used for liquefying gases with low liquefaction temperature, such as helium, hydrogen, nitrogen, methane and the like, and promotes the precooling of the movable small-sized refrigerating machine and the large-scale application of the liquefaction device.

Drawings

Fig. 1 is a schematic structural diagram of a two-stage GM refrigerator high-efficiency liquefaction system of example 1 of the present invention.

FIG. 2 is a schematic diagram of an efficient precooling system using a single-stage Stirling refrigerator in example 2.

FIG. 3 is a schematic diagram of an efficient precooling and liquefying system adopting a two-stage Stirling pulse tube refrigerator in example 3.

In fig. 1: 1. a compression device; 2. a compressor low pressure gas storage tank; 3. a compressor cooler and a filter; 4. a compressor high pressure gas storage tank; 5. a GM type compressor high-low pressure distributing valve; 6. a refrigerator inlet passage; 7. a refrigerator cylinder; 8. a first stage regenerator; 9. a first stage expansion piston seal mechanism; 10. the clearance between the first stage expansion piston and the cylinder; 11. a first stage expansion piston; 12. a first stage cold side heat exchanger; 13. a first stage expansion chamber; 14. a second stage expansion piston seal mechanism; 15. the clearance between the second-stage expansion piston and the cylinder; 16. a second stage cold side heat exchanger; 17. a second stage expansion chamber; 28. d, direct current; 18. an interstage DC connection channel; 19. a first stage to hot end DC link channel; 20. a direct current control valve; 21. a material source; 22. a feed control mechanism; 23. the heat exchange component is arranged on the outer wall of the cylinder; 24. a cold end heat exchange assembly; 25. a material to be precooled collecting assembly; 26. a second stage regenerator; 27. a second stage expansion piston.

Detailed Description

The efficient precooling and liquefying system of the gap type refrigerator in the embodiment comprises a regenerative refrigerating module and a precooling and liquefying module;

the regenerative refrigeration module comprises a regenerative refrigerator unit and a direct-current internal circulation unit; the regenerative refrigerator unit comprises a compressor device 1, a regenerator, a cold end heat exchanger 12, an expansion piston and an internal gap structure which are connected in sequence;

the direct current internal circulation unit is as follows: the direct current 28 is introduced into the internal gap structure from a specific position, the material to be precooled is precooled by using the cold energy in the heat regenerator, and then returns to the heat regenerator through the compressor 1, so that the direct current internal circulation is completed, and the circulation flow is controlled through the direct current control valve 20. And the direct-current circulation pipeline is also provided with a direct-current internal circulation control assembly. The internal clearance structure comprises a clearance formed by an expansion piston and a cylinder and a clearance formed by a plurality of layers of channels in a pressure bearing pipe of a regenerator or a pulse pipe.

The pre-cooling and liquefying module comprises a material source 21, a feeding control mechanism 22, a feeding and cylinder outer wall heat exchange assembly 23, a cold end heat exchange pipeline 24 and a material to be pre-cooled collecting assembly 25 which are sequentially communicated, wherein materials in the material source 21 are pre-cooled at the feeding and cylinder outer wall heat exchange assembly 23 and enter the cold material collecting assembly 25. The gas is liquefied in the cold heat exchange line 24 and enters the cold charge collecting assembly 25.

The location where the direct current 28 is introduced into the internal gap structure is at the cold end of the regenerator or anywhere from the cold end of the regenerator to the hot end of the regenerator. The location of the exit of dc 28 from the internal gap structure includes the hot end of the regenerator, and anywhere from the hot end of the regenerator to the cold end of the regenerator. In specific implementation, the direct current 28 is led out from the internal gap structure and then can be directly led into the heat regenerator, or led into the low-voltage component and then led into the heat regenerator, or driven by the high-voltage component; the low-pressure component is a low-pressure pipeline or a low-pressure cavity formed by arranging a one-way valve; the high-pressure component is a high-pressure pipeline or a high-pressure cavity formed by arranging a one-way valve.

As an optional implementation manner in the embodiment, the material source includes a material source at a higher temperature and a gas evaporated in the cold material collecting assembly, and a combination of the material source at the higher temperature and the gas evaporated in the cold material collecting assembly, when the gas evaporated in the material source cold material collecting assembly, the cold material collecting assembly is connected with the heat exchange assembly on the outer wall of the cylinder, a certain amount of cryogenic liquid is pre-filled in the cold material collecting assembly, when the liquid in the cold material collecting assembly absorbs heat and is gasified, the liquid is liquefied again by the cryogenic refrigerator, and as long as the power for cold taking is lower than the power for liquefaction, the cold material collecting assembly can be modified into a constant temperature cold source. When the embodiment is used for compensating external heat leakage, the liquefaction system is substantially transformed into a re-liquefaction system.

The feeding quantity of the pre-cooling and liquefying modules is the maximum value which is obtained by matching the heat capacity of the material with the heat capacity of the direct current in each temperature zone, namely the total heat capacity of the material integrated from the lowest temperature to the higher temperature is just equal to the working condition of the total heat capacity of the direct current, and the range of the feeding quantity is between the maximum value and zero. When the amount of feed is less than the maximum, this direct flow can reduce expansion gap related losses, such as shuttle losses, pumping losses, and thereby increase refrigeration efficiency. Under the working condition that the feeding quantity is zero, the efficient precooling and liquefying system of the gap type refrigerator can keep the regenerative refrigerating module, remove the precooling and liquefying module and concentrate on the improvement of the refrigerating efficiency; of course, the regenerative refrigeration module and the pre-cooling and liquefying module can be simultaneously reserved.

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1

As shown in fig. 1, the regenerative refrigerator efficient liquefaction system using direct current of the present embodiment includes a two-stage GM refrigerator module and a liquefaction module.

The two-stage GM refrigerator module comprises a regenerative refrigerator unit and a direct-current internal circulation unit. The regenerative refrigerator unit comprises a compression device 1, a compressor low-pressure air storage tank 2, a compressor cooler and filtering device 3, a compressor high-pressure air storage tank 4, a GM type compressor high-low pressure gas distribution valve 5, a refrigerator gas inlet channel 6, a refrigerator cylinder 7, a first-stage expansion piston 11, a first-stage regenerator 8, a first-stage expansion piston sealing mechanism 9, a gap 10 between the first-stage expansion piston and the cylinder, a second-stage expansion piston 27, a second-stage regenerator 26, a first-stage cold end heat exchanger 12, a first-stage expansion cavity 13, a second-stage expansion piston sealing mechanism 14, a gap 15 between the second-stage expansion piston and the cylinder, a second-stage cold end heat exchanger 16 and a second-stage expansion cavity 17. The dc internal circulation unit includes a dc 28, an inter-stage dc link 18, a first stage to warm end dc link 19, a dc control valve 20.

The liquefaction module comprises an air source 21, an air inlet control mechanism 22, an air cylinder outer wall heat exchange assembly 23, a cold end heat exchange assembly 24 and a liquid collection assembly 25 which are sequentially communicated.

The working process of the embodiment is as follows:

the system installation is completed according to the flow, system components and pipelines except the high-pressure gas source are subjected to gas replacement for many times, and the working medium is filled with the gas working medium with working pressure, so that the purity of the working medium in the system can be ensured. The compressor 1 is operated firstly, the refrigerating machine begins to cool, when the temperature of the heat regenerator cold-end heat exchanger 16 is reduced to be lower than the liquefaction temperature of the working medium, the valves of the direct-flow control valve 20 and the feeding control mechanism 22 are adjusted, the direct-flow and the flow of the liquefied gas to be liquefied are controlled, and the pressure of the liquefied gas to be liquefied is adjusted until the stable liquefaction rate is obtained.

Example 2

As shown in fig. 2, the efficient liquefaction system of the regenerative refrigerator using direct current of the present embodiment includes a single-stage stirling refrigerator module and a liquid pre-cooling module.

The single-stage Stirling refrigerator module comprises a regenerative refrigerator unit and a direct-current internal circulation unit. The regenerative refrigerator unit comprises a piston type compression device 1, a compressor cooler 3, a refrigerator air inlet channel 6, a refrigerator air cylinder 7, a first-stage expansion piston 11, a first-stage regenerative heater 8, a first-stage expansion piston sealing mechanism 9, a gap 10 between the first-stage expansion piston and the air cylinder, a first-stage cold end heat exchanger 12 and a first-stage expansion cavity 13. The direct-current internal circulation unit comprises a direct current 28, a direct-current outlet cylinder connecting channel 19, a direct-current control valve 20, a low-pressure air reservoir 30 and a low-pressure one-way valve 31.

The liquid precooling module comprises a liquid source 21, a liquid inlet control mechanism 22, a cylinder outer wall heat exchange assembly 23, a cold end heat exchange assembly 24 and a liquid collecting assembly 25 which are sequentially communicated.

The working process of the embodiment is as follows:

the system installation is completed according to the flow, the system components and the pipeline of the single-stage Stirling refrigerator module are subjected to gas replacement for many times, and the working medium is filled into the system, so that the purity of the working medium in the system can be ensured. The piston compressor 1 is operated firstly, the refrigerating machine begins to cool, when the temperature of the cold end heat exchanger 12 of the heat regenerator is reduced to be lower than the set temperature, the size of the low-pressure one-way valve 31 is adjusted, the pressure in the low-pressure air reservoir 30 is stabilized to be lower than the alternating flow average pressure, the liquid inlet control mechanism 22 is opened, and the liquid to be precooled is continuously cooled from the liquid source 21 through the cylinder outer wall heat exchange assembly 23 and the cold end heat exchange assembly 24 until the liquid flows into the liquid collection assembly 25. And adjusting the direct-current control valve 20 and the liquid inlet control mechanism 22 to control the direct-current flow and the flow of the liquid to be precooled until a stable precooling flow rate is obtained.

Example 3

As shown in fig. 3, the high-efficiency liquefaction system of the regenerative refrigerator using direct current of the present embodiment includes a two-stage pulse tube refrigerator module and a pre-cooling and liquefaction module.

The secondary pulse tube refrigerator module comprises a regenerative refrigerator unit and a direct-current internal circulation unit. The regenerative refrigerator unit comprises a piston type compression device 1, a compressor cooler 3, a refrigerator inlet channel 6, a first-stage regenerator 8, a first-stage cold end connecting pipe 40, a first-stage pulse tube cold end heat exchanger 41, a first-stage pulse tube 42, a first-stage pulse tube hot end heat exchanger 43 and a first-stage phase modulation mechanism 44, wherein gas is divided into two paths in the first-stage regenerator 8; the second path is connected with a first-stage cold end heat exchanger 12, a second-stage heat regenerator 26, a second-stage cold end heat exchanger 16, a second-stage cold end connecting pipe 46, a second-stage pulse tube cold end heat exchanger 47, a second-stage pulse tube 48, a second-stage pulse tube hot end heat exchanger 49 and a second-stage phase modulation mechanism 50 in sequence.

The direct current internal circulation unit is divided into two paths, and comprises a direct current 28, a second-stage regenerator side insertion channel 27, a second-stage regenerator side gap 15, a first-stage regenerator side insertion channel 11, a first-stage regenerator side gap 10, a first-stage to hot-end direct current connecting channel 19, a regenerator side direct current control valve 20, a low-pressure air reservoir 30 and a low-pressure one-way valve 31, wherein the other direct current comprises a direct current 54 flowing to a pulse tube side, a second-stage pulse tube side insertion channel 51, a second-stage pulse tube side gap 52 and a regenerator side direct current control valve 55.

The pre-cooling and liquefying module comprises two paths, wherein the two paths of working media to be pre-cooled and liquefied are different. One path is a heat regenerator side precooling module, and comprises a gas source 21, a feeding control mechanism 22, a cylinder outer wall heat exchange assembly 23 and a gas collection assembly 25 which are sequentially communicated; and the other path is a pulse tube side liquefaction module which comprises an air source 56, an air inlet pressure control mechanism 57, a cylinder outer wall heat exchange assembly 58, a cold end heat exchange assembly 59 and a liquid collection assembly 60 which are sequentially communicated.

The working process of the embodiment is as follows:

the system installation is completed according to the flow, system components and pipelines except the high-pressure gas source are subjected to gas replacement for many times, and the working medium is filled with the gas working medium with working pressure, so that the purity of the working medium in the system can be ensured. The piston compressor 1 is operated firstly, the refrigerating machine begins to cool, when the temperature of the heat regenerator cold end heat exchanger 16 is reduced to be lower than the liquefaction temperature of the pulse tube side working medium, the size of the low-pressure one-way valve 31 is adjusted, and the pressure in the low-pressure gas reservoir 30 is stabilized to be lower than the average alternating flow pressure.

For the pre-cooling module, the valves of the dc control valve 20 and the feeding control mechanism 22 are opened, so that the dc flows through the second-stage regenerator 26, flows out of the regenerator through the small hole in the second-stage regenerator side insertion channel 27, enters the second-stage regenerator side gap 15, flows along the second-stage regenerator side gap 15, the first-stage regenerator side gap 10, and the sealing portion of the first-stage to hot-end dc connection channel 19, and the gas to be pre-cooled is cooled by the cylinder outer wall heat exchange assembly 23 until flowing into the gas collection assembly 25. The valves of the direct-flow control valve 20 and the feeding control mechanism 22 are adjusted to control the direct-flow rate and the flow rate of the gas to be precooled, and the pressure of the gas to be precooled is adjusted until a stable precooling flow rate is obtained.

For the liquefaction module, the dc control valve 55 and the valves of the feed control mechanism 57 are opened to allow a dc flow through the second stage regenerator 26, the second stage cold side connecting tube 46, the second stage pulse tube cold side heat exchanger 47, into the second stage pulse tube side gap 52, through the cold side to the hot side. The liquefied gas flows out of the gas source 56, is continuously cooled through the cylinder outer wall heat exchange assembly 58 and the cold end heat exchange assembly 59 until flowing into the liquid collection assembly 60. The valves of the direct flow control valve 55 and the feed control mechanism 57 are adjusted to control the direct flow and the flow of the gas to be liquefied, and the pressure of the gas to be precooled is adjusted until a stable liquefaction flow rate is obtained.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.