CN217504027U - High-efficiency precooling and liquefying system of coupling expansion mechanism and regenerative refrigerator - Google Patents

Abstract

The utility model relates to a high-efficiency precooling and liquefying system of a coupling expansion mechanism and a regenerative refrigerator, which comprises a regenerative refrigerating module, an expansion and compression module and a precooling and liquefying module; the regenerative refrigeration module comprises a regenerative refrigerator unit and a direct-current external circulation unit; the regenerative refrigerator unit comprises a compressor device, a heat regenerator and a cold end heat exchanger which are connected in sequence; in the direct-current external circulation unit, direct current is led out of the refrigerator unit from any position, passes through a plurality of channels and then returns to the heat regenerator to complete direct-current circulation; the direct current external circulation unit is internally provided with a direct current control valve so as to control the direct current flow. Compared with the prior art, the utility model discloses cross and to be carried out the inflation step-down by the direct current of drawing forth, increased inflation refrigeration effect to obtain and treat the near pressure of precooling material, make its specific heat capacity similar, make the equal amount draw forth that the direct current can precool and liquefy more treat the precooling material, thereby improve precooling and liquefaction efficiency.

Description

Efficient precooling and liquefaction system coupled with expansion mechanism and regenerative chiller

technical field

The utility model relates to the technical field of refrigeration, in particular to a high-efficiency precooling and liquefaction system coupled with an expansion mechanism and a regenerative refrigerator.

Background technique

The regenerative refrigerator is a refrigeration technology in the form of alternating flow. The regenerator is used to realize the periodic heat storage and release between the gas working medium and the regenerative filler, and the expansion of the gas is used to generate the refrigeration effect. The regenerator generally has a large specific surface area per unit volume, and the structural forms include wire mesh, pellet packing, gap type and so on.

Direct current means that the mass of the air flowing in the forward direction and the reverse flow of a certain section in a cycle is not equal, and there is a net mass flow flowing in one direction. The direct current is also called the direct current circulating mass flow. Regenerative cryogenic refrigerators have the advantages of high reliability, simple structure and high efficiency, and are widely used in low temperature technologies such as gas liquefaction and superconducting cooling.

The expansion mechanism includes two functions: throttling expansion and external work expansion, both of which realize the depressurization of the gas; the ideal regenerative cryogenic refrigerator does not have direct current in operation. With the introduction of the bidirectional air intake structure in the pulse tube refrigerator, a closed circuit consisting of the bidirectional air intake valve, the regenerator and the pulse tube is formed, which induces a direct current flow. A series of theories and experiments show that DC with a certain flow rate has the potential to improve the refrigeration performance of pulse tube refrigerators.

The Joule-Tomson (JT or J-T for short) throttling refrigerator is a refrigeration effect produced by the gas in the process of isoenthalpy depressurization. It has a simple structure and can be operated with liquid, so it is used in the Linde-Hampson cycle. It is widely used in the Kraut cycle, and has a significant effect on the refrigeration of the lowest temperature area. For small low-temperature refrigeration systems, throttling refrigerators pre-cooled by regenerative refrigerators can obtain better performance at deep and low temperatures. Regenerative refrigerators include GM refrigerators, pulse tube refrigerators, Stirling refrigerators or a combination of the two. The throttling refrigerator is composed of a compressor, a counter-flow heat exchanger formed by a high-pressure pipeline and a low-pressure pipeline, a throttling element, and a cold-end heat exchanger. The counter-flow heat exchanger is pre-cooled by the regenerative chiller at some temperature points.

Expansion refrigerators use compressed gas to expand and depressurize to work outward to reduce the temperature of the gas, thereby obtaining the refrigeration effect. The expansion refrigerator is composed of a compressor, a counter-flow heat exchanger formed by a high-pressure pipeline and a low-pressure pipeline, an expansion mechanism, and a cold-end heat exchanger. By pre-cooling some temperature points of the counter-flow heat exchanger by the regenerative refrigerator, the heat exchange efficiency can be improved, so that the expansion refrigeration efficiency can be improved.

However, although conventional throttling refrigerators pre-cooled by regenerative refrigerators and expansion refrigerators pre-cooled by regenerative refrigerators can produce refrigeration effects through expansion and depressurization, they can only provide cooling capacity at the cold end. It cannot provide distributed cooling capacity at intermediate temperatures from the cold side to the hot side.

Cryogenic gas liquefaction is an important industrial application of cryogenic engineering, and there is a large industrial demand for air, natural gas, hydrogen, helium and other working fluids. The improvement in liquefaction efficiency will significantly reduce equipment costs and reduce energy consumption. Cryogenic gaseous storage is also an important application in industry, especially for hydrogen, which liquefies at very low temperatures. At present, there are solutions in hydrogen vehicles with a filling pressure of 30 MPa and an operating temperature range of 33 K to room temperature. The corresponding gaseous pre-cooling also has a large amount of cooling demand. The pre-cooling of low temperature liquid includes obtaining low temperature liquid such as ethanol to realize the function of thermostat or cooling. The pre-cooling of low-temperature solids includes regenerators for cold storage, etc.

The patent with publication number CN202010864762.1 discloses "a high-efficiency liquefaction system of a regenerative refrigerator using direct current", although it has the advantage of direct current drawn from the regenerative refrigerator for precooling and liquefaction, the direct current drawn from the refrigerator The pressure is generally much higher than the pressure of the gas to be precooled. Since the specific heat capacity of the gas working fluid varies with the pressure, the specific heat capacities of the two fluids do not match, resulting in more direct current to cool the gas to be pre-cooled, reducing the pre-cooling efficiency.

Utility model content

The purpose of this utility model is to provide a high-efficiency pre-cooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator in order to overcome the above-mentioned defects of the prior art. The circuit and the partition heat exchanger return to the hot end of the regenerator to form a stable DC cycle, so that the DC cycle absorbs cold energy inside the regenerator, and exchanges heat with the precooling and liquefaction modules through the partition wall heat exchanger. Material to be pre-cooled. After the DC is depressurized by the expansion mechanism, on the one hand, the specific heat capacity of the gas in the DC is similar to the specific heat capacity of the pre-cooled material, and on the other hand, the expansion refrigeration effect is produced, and the cooling capacity of the cold end is increased.

The applicant believes that the above-mentioned aspects can make a certain amount of direct current achieve more pre-cooling material to be pre-cooled than without expansion, thereby improving the pre-cooling efficiency.

After the depressurization, the gas in the direct current is compressed by the compression mechanism to increase the pressure. It can be raised to not lower than the pressure of the low-pressure component and return to the compressor through the low-pressure chamber, or it can be raised to a pressure of not lower than the high-pressure component and return to the compressor through the high-pressure chamber. Of course, it can also be no lower than a certain pressure between low pressure and high pressure, which can be returned to the compressor or the hot end of the regenerator.

The purpose of the present utility model can be achieved through the following technical solutions:

The purpose of this technical solution is to protect a high-efficiency pre-cooling and liquefaction system coupled with an expansion mechanism and a regenerative refrigerator, including a regenerative refrigeration module, an expansion and compression module, and a pre-cooling and liquefaction module;

The regenerative refrigeration module includes a regenerative refrigerator unit and a DC external circulation unit;

The regenerative refrigerator unit includes a compressor device, a regenerator, and a cold-end heat exchanger connected in sequence;

In the DC external circulation unit, DC leads from any position to the refrigerator unit, passes through multiple channels (including expansion mechanisms, partition heat exchangers, compression mechanisms, valves, etc.), and then returns to the regenerator to complete the DC cycle. ;

The DC external circulation unit is provided with a DC control valve, so as to control the size of the DC flow;

The expansion and compression module includes an expansion mechanism arranged on the first temperature zone on the DC external circulation unit, a compression mechanism arranged on the second temperature zone on the DC external circulation unit, a buffer gas store, a compressor cooler and a filter device, The temperature of the second temperature region is higher than that of the first temperature region, wherein the direct current is reduced to a preset low pressure value through the expansion mechanism, and compressed to the pressure of the regenerative refrigerator through the compression mechanism, so as to form between the expansion mechanism and the compression mechanism. A low-pressure section with a preset pressure value and an expansion refrigeration effect;

Specifically, the expansion and compression module includes an expansion mechanism added in a lower temperature area of the DC external circulation unit, a compression mechanism added in a higher temperature area, and a buffer gas store, a compression mechanism cooler and a filter device that can be added as needed. The direct current drops to a certain low pressure through the expansion mechanism, and is compressed to the pressure of the regenerative refrigerator through the compression mechanism, thereby forming a section of low pressure between the expansion mechanism and the compression mechanism, and produces the expansion refrigeration effect and increases the cooling capacity. The attached buffer gas storage can play the role of buffering the gas pressure, the compressor cooler can discharge the compression heat, and the filter device can filter the solid particles and absorb the compressed oil. When the compression mechanism cooler and filter device are not provided, it can be completed in the compression mechanism of the regenerative refrigerator.

The pre-cooling and liquefaction module includes a material source to be pre-cooled, a feed control mechanism, a partition heat exchanger, a cold-end heat exchange pipeline, and a cold material collection component, which are sequentially connected to the material to be pre-cooled. The material to be pre-cooled in the material source The liquefaction module also includes a device for liquefying the material in the cold-end heat exchange pipeline, mainly including a heat exchanger, a liquid collection component, a liquid inlet and outlet device, a liquid Position measuring instruments, etc.

Further, the position of the direct current extraction regenerator structure is the cold end of the regenerator, or any position in the section between the cold end of the regenerator and the hot end of the regenerator;

The position where the direct current is introduced into the regenerative refrigerator system from the dividing wall heat exchanger is any position between the hot end of the regenerator and the compressor section, and the section between the hot end of the regenerator and the cold end of the regenerator;

The direct current is drawn from one or more positions at the same time, so as to form one direct current or multiple direct currents, and one or more partition heat exchangers are correspondingly arranged on the direct current.

Further, the expansion mechanism is arranged on a direct current or on a plurality of direct currents respectively;

The expansion mechanism is one of a single expansion mechanism, multiple expansion mechanisms connected in series, multiple expansion mechanisms connected in parallel, and multiple expansion mechanisms combined in series and parallel;

The position of the expansion mechanism on the direct current is the cold end or any position between the cold end and the hot end;

The expansion mechanism includes one of a small hole valve, a small hole, a capillary pipe, a slit, and a porous medium, so as to realize throttling and pressure reduction through frictional resistance and local resistance;

The expansion mechanism also includes a turbo expander, a piston expander, and other mechanisms that achieve depressurization by doing external work;

The buffer gas storage is arranged after the expansion mechanism, and the buffer gas storage is arranged at any position between the expansion mechanism and the compression mechanism.

Further, the compression mechanism is arranged on one DC or on multiple DCs respectively;

The compression mechanism is one of a single compression mechanism, multiple compression mechanisms connected in series, multiple compression mechanisms connected in parallel, and multiple compression mechanisms combined in series and parallel;

The position of the compression mechanism on the direct current is the hot end or any position between the hot end and the cold end;

The compression mechanism is a volume-type supercharging mechanism or a turbine-type speed-type supercharging mechanism, and the volume-type supercharging mechanism is one of a piston type, a screw type, and a scroll type supercharging mechanism.

Further, after the direct current is drawn out from the compression mechanism, it is introduced into the regenerator, or the low-voltage component and the high-voltage component are introduced into the regenerator, thereby forming a cycle;

That is, the direct current can be compressed to a pressure not lower than a certain pressure of the regenerative refrigerator, including not lower than the lowest pressure, not lower than the highest pressure or not lower than a certain pressure between the highest pressure and the lowest pressure;

The low-pressure component is the low-pressure pipeline of a valved compressor (GM type) or a low-pressure cavity formed by setting a check valve in a valveless compressor (Sterling type) and a valved compressor; the low-pressure pipeline is: Before compression, it includes low-pressure gas distribution pipes, low-pressure gas storage tanks and other structures; the low-pressure cavity formed by setting the check valve includes a low-pressure gas reservoir and a low-pressure check valve arranged along the DC movement direction, and the low-pressure gas reservoir is located in the DC control valve. downstream.

The high-pressure component is a high-pressure pipeline of a valved compressor (GM type) or a high-pressure chamber formed by a one-way valve in a valveless compressor (Sterling type) and a valved compressor. The high-pressure pipeline is a compressed high-pressure gas distribution pipe, a high-pressure gas storage tank and other structures;

Further, the regenerative refrigerator unit is a refrigerator that uses regenerator components to realize the alternating storage and release of heat, and specifically includes: a Gifford-Mcmahon (Gifford-Mcmahon) with an expansion piston mechanism. , GM) refrigerators, Solvey refrigerators, Stirling refrigerators, Vurlleumier (VM) refrigerators, and pulse tube refrigerators without an expansion piston mechanism, or a variety of refrigerators. Hybrid structure of multi-level coupling. The pulse-tube refrigerators include GM-type pulse-tube refrigerators and Stirling-type pulse-tube refrigerators.

Further, the pulse tube refrigeration module further includes a cold end connecting tube, a pulse tube cold end heat exchanger, a pulse tube, a pulse tube hot end heat exchanger and a phase modulation mechanism connected in sequence, and the cold end connecting tube is composed of a cold end. The end heat exchanger leads out.

Further, the regenerative refrigeration module is a regenerator built-in structure or a regenerator external structure;

In the regenerator built-in structure, the regenerator is built in the expansion piston, and the regenerator moves together with the expansion piston;

In the external structure of the regenerator, the expansion piston and the regenerator are arranged separately, generally the regenerator does not move, and the expansion piston moves;

The regenerative refrigeration module includes a single-stage structure and a multi-stage coupling structure, and the multi-stage coupling structure includes a multi-stage thermal coupling structure, a multi-stage gas coupling structure, and a thermal coupling and gas coupling hybrid structure. The multi-stage structure can achieve lower cooling temperature and provide cooling capacity in multiple temperature zones. Multilevel includes two levels and more than two levels.

Further, the material source includes the material source at a higher temperature and the gas evaporated in the cold material collection component, and the combination of the material source at a higher temperature and the evaporated gas. Further, the feeding control mechanism is a pressure control valve, a capillary tube, a nozzle or a resistance element formed by a porous medium.

Further, the average working pressure in the regenerative refrigeration module is generally greater than 1 times the atmospheric pressure (absolute pressure), and can be extended to below the atmospheric pressure under special circumstances, which is 0.1-2000 times the atmospheric pressure (ie 0.01-200 MPa). The working pressure of the pre-cooling and liquefaction module is generally different from the pressure in the regenerative refrigeration module, which is often close to atmospheric pressure (absolute pressure), but high pressure can be achieved in the high-pressure low-temperature gas storage system, so it can include 0.01 to 2000 times atmospheric pressure (ie 0.001-200 MPa pressure range).

Further, the precooling and liquefaction module includes a precooling function, a liquefaction function, and a combination of the precooling function and the liquefaction function, and the liquefaction amount of the material to be precooled accounts for the total amount of the material to be precooled. 100% range.

The material to be precooled includes gas, liquid or solid, and any two or three mixtures of gaseous, liquid and solid phase states.

The materials to be pre-cooled include pure substances and mixtures of various substances.

Further, the feed quantity of the pre-cooling and liquefaction module meets the maximum value of the heat capacity of the material and the direct current heat capacity in each temperature zone, and the range of the feed quantity is between the maximum value and zero.

Under the condition of zero feed quantity, the high-efficiency pre-cooling and liquefaction system coupling expansion mechanism and regenerative refrigerator includes retaining regenerative refrigeration module, expansion and compression module without pre-cooling and liquefaction module, or At the same time, two cases of regenerative refrigeration module, expansion and compression module, and pre-cooling and liquefaction module are retained.

Further, if the partition wall heat exchanger for liquefaction is removed, distributed cooling capacity can be provided as a refrigeration cycle.

Further, the DC external circulation unit of the regenerative refrigeration module includes single-channel DC and multi-channel DC drawn from the refrigerator. For example, in the structure in which the regenerator and the expansion piston are placed in parallel, two direct currents can be formed at the regenerator and the expansion piston, respectively. Multiple DCs can be formed according to temperature segments.

Since the specific heat capacity of the gaseous working medium changes with the pressure, the pressure of the direct current drawn from the refrigerator is generally higher than the pressure of the gas to be pre-cooled, and the specific heat capacities of the two fluids do not match, resulting in the need for more direct current to cool the gas to be pre-cooled. Reduced pre-cooling efficiency. Compared with the prior art, the utility model has the following technical advantages:

1) The present utility model is a high-efficiency precooling and liquefaction system for a regenerative refrigerator using a DC parallel-coupled expansion mechanism, so that the DC cycle absorbs cold energy inside the regenerator, and is exchanged with the precooling and liquefaction module through the partition wall heat exchanger. Heat, pre-cool the material to be pre-cooled. In the present invention, after the direct current is depressurized by the expansion mechanism, on the one hand, the specific heat capacity of the gas in the direct current is similar to the specific heat capacity of the pre-cooled material, and on the other hand, the expansion refrigeration effect is produced, and the cooling capacity of the cold end is increased. Both of these two aspects can make a certain amount of direct current achieve more pre-cooling material to be pre-cooled than without expansion, thereby improving the pre-cooling efficiency.

2) The regenerator in this utility model can absorb a certain amount of DC enthalpy current, and the increase of the cold end enthalpy current caused by a suitable size of DC is much smaller than the total enthalpy current absorbed by the regenerator, so the full use of the drawn DC , which can improve the pre-cooling and liquefaction capacity of the refrigerator. Especially in the region where the working fluid is close to the critical temperature, there is a maximum allowable direct current due to the effect of the actual gas. In this direct current range, the COP of the actual regenerator is slightly reduced by the direct current.

3) The low-temperature liquid produced by the high-efficiency pre-cooling and liquefaction system of the direct current regenerative refrigerator of the present invention can be used as a constant temperature cold source to meet the low temperature requirement of a stable constant temperature.

4) The small low-temperature refrigerator in the structural form of the utility model can obviously improve the liquefaction efficiency, and the equipment is small and movable, and can be used to liquefy gases with low liquefaction temperature such as helium, hydrogen, nitrogen, methane, etc., and promote mobile small-scale refrigeration. Large-scale application of machine pre-cooling and liquefaction equipment.

Description of drawings

FIG. 1 is a schematic structural diagram of a high-efficiency liquefaction system of a two-stage GM refrigerator according to Embodiment 1 of the present invention.

Figure 2 is a schematic structural diagram of the high-efficiency cooling system of the two-stage GM refrigerator in Example 2.

Fig. 3 is a schematic diagram of a high-efficiency pre-cooling system using a single-stage Stirling refrigerator in Example 3.

4 is a schematic diagram of a high-efficiency precooling and liquefaction system using a two-stage GM-type pulse tube refrigerator in Example 4.

In the figure: 1. Compression device; 2. Compressor low-pressure air storage tank; 3. Compressor cooler and filter device; 4. Compressor high-pressure air storage tank; 5. GM type compressor high and low pressure air distribution valve; 6. Refrigerator intake passage; 7. Refrigerator cylinder; 8. First-stage regenerator; 9. First-stage expansion piston sealing mechanism; 10. Gap between first-stage expansion piston and cylinder; 11. First-stage expansion piston ; 12. The first-stage cold end heat exchanger; 13. The first-stage expansion chamber; 14. The second-stage expansion piston sealing mechanism; 15. The gap between the second-stage expansion piston and the cylinder; 16. The second-stage cold end exchange Heater; 17, second-stage expansion chamber; 28, direct current; 20, direct current control valve; 21, material source; 22, feed control mechanism; 23, material to be pre-cooled; 24, cold end heat exchange component; 25, Material collection component to be pre-cooled; 26, second-stage regenerator; 27, second-stage expansion piston; 29, expansion mechanism; 30, partition heat exchanger; 31, low pressure buffer gas storage; 32, compression mechanism; 33 , compressor cooler and filter device.

Detailed ways

The present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. Features such as component models, material names, connection structures, control methods, algorithms, etc., which are not explicitly described in this technical solution, are regarded as common technical features disclosed in the prior art.

The high-efficiency precooling and liquefaction system coupling the expansion mechanism and the regenerative refrigerator in this embodiment includes a regenerative refrigeration module, an expansion and compression module, and a precooling and liquefaction module;

The regenerative refrigeration module includes a regenerative refrigerator unit and a DC external circulation unit; the regenerative refrigerator unit includes a compressor device 1, a regenerator, and a cold-end heat exchanger 12 connected in sequence;

The DC external circulation unit is: DC leads out the refrigerator unit from a specific position, the DC passes through a series of channels, and then returns to the regenerator to complete the DC circulation, and the DC flow rate is controlled by the DC control valve 20 .

The expansion and compression module includes the expansion mechanism added in the lower temperature area of the DC external circulation unit, the compression mechanism added in the higher temperature area, and the attached buffer gas storage, compression mechanism cooler and filter device. The direct current drops to a certain low pressure through the expansion mechanism, and is compressed to the pressure of the regenerative refrigerator through the compression mechanism, thereby forming a section of low pressure between the expansion mechanism and the compression mechanism, and producing an expansion refrigeration effect.

The pre-cooling and liquefaction module includes a material source 21 of the material to be pre-cooled, a feed control mechanism 22, a partition heat exchanger 30, a cold end heat exchange pipeline 24 and a cold material collection component 25, which are connected in sequence. The material source 21 The material to be pre-cooled inside is pre-cooled by the partition heat exchanger 30 and enters the cold material collection component 25 . The liquefaction module also includes a device for liquefying the material in the cold-end heat exchange pipeline 24 .

After the DC 28 is drawn out from the compression mechanism, it can be introduced into the regenerator, or the low-voltage component and the high-voltage component can be introduced into the regenerator to form a cycle. That is, the direct current can be compressed to a pressure not lower than a certain pressure of the regenerative refrigerator, including not lower than the lowest pressure, not lower than the highest pressure, or not lower than a certain pressure between the highest pressure and the lowest pressure.

As an optional implementation in the embodiment, the material source includes the material source at a higher temperature and the gas evaporated in the cold material collection component, and the combination of the material source at a higher temperature and the evaporated gas, when When the gas evaporated in the cold material collection component of the material source, the cold material collection component is connected with the partition heat exchanger, and a certain amount of low-temperature liquid is pre-installed in the cold material collection component. When the liquid in the cold material collection component absorbs heat For gasification, the cooling capacity provided by the cryogenic refrigerator and the expansion mechanism will be liquefied again. As long as the cooling power is lower than the liquefaction power, the cold material collection component can be transformed into a constant temperature cold source. When this embodiment is used to compensate for external heat leakage, the liquefaction system has been substantially transformed into a reliquefaction system.

The feed quantity of the pre-cooling and liquefaction module meets the maximum value of the heat capacity of each temperature zone and the direct current heat capacity, and the feed quantity is between the maximum value and zero. This direct current can be used to provide additional cooling capacity when the feed quantity is less than the maximum value. Under the condition of zero feed quantity, the high-efficiency pre-cooling and liquefaction system coupled with the expansion mechanism and the regenerative refrigerator can retain the regenerative refrigeration module and the expansion and compression module, and remove the pre-cooling and liquefaction module. , focusing on the improvement of cooling efficiency; of course, the pre-cooling and liquefaction modules can also be retained at the same time.

Example 1

As shown in FIG. 1 , the high-efficiency precooling and liquefaction system of the coupled expansion mechanism and the regenerative refrigerator in this embodiment includes a two-stage GM refrigerator module, an expansion and compression module, and a liquefaction module.

The secondary GM chiller module includes a regenerative chiller unit and a DC external circulation unit. The regenerative refrigerator unit includes compression device 1, compressor low-pressure air storage tank 2, compressor cooler and filter device 3, compressor high-pressure air storage tank 4, GM type compressor high and low pressure air distribution valve 5, refrigerator inlet. Air passage 6, refrigerator cylinder 7, first-stage expansion piston 11, first-stage regenerator 8, first-stage expansion piston sealing mechanism 9, first-stage expansion piston and cylinder gap 10, second-stage expansion piston 27 , the second-stage regenerator 26, the first-stage cold end heat exchanger 12, the first-stage expansion chamber 13, the second-stage expansion piston sealing mechanism 14, the gap 15 between the second-stage expansion piston and the cylinder, the second-stage cooling End heat exchanger 16 , second-stage expansion chamber 17 . The DC external circulation unit includes a DC 28 and a DC control valve 20 .

The expansion and compression module includes an expansion mechanism 29 and a low pressure buffer gas reservoir 31 , a compression mechanism 32 , a compression mechanism cooler and a filter device 33 .

The liquefaction module includes an air source 21 , an air intake control mechanism 22 , a material to be pre-cooled 23 , a partition heat exchanger 30 , a cold end heat exchange component 24 , and a liquid collection component 25 that are communicated in sequence.

The working process of this embodiment is:

Complete the system installation according to the above process, and fill in the gas working medium under the working pressure. Under the condition of room temperature, first set the throttle valve 29 to a certain opening. After the setting is completed, start the compressor 1, and the refrigerator will start to cool down. The control valve 20 and the valve of the feeding control mechanism 22 control the DC flow and the flow of the gas to be liquefied, and start the compression mechanism 32, and the DC flow through the partition heat exchanger is compressed to the original low pressure chamber pressure by the compression mechanism 32 to form a stable pressure. cycle. The attached buffer gas storage 31 is stabilized at low pressure, and the compressor cooler and filter device 33 discharge the heat of compression, and filter and adsorb impurities. Adjust the valve of the feed control mechanism 22 to adjust the pressure of the gas to be liquefied; then adjust the DC control valve 20 and the compression mechanism 32, adjust the pressure of the DC gas between the throttle valve 29 and the compression mechanism 32 to the required value, and optimize to obtain stable Liquefaction rate.

Example 2

Low temperature storage system cooled by new regenerative chiller

As shown in FIG. 2, the coupled expansion mechanism and the high-efficiency pre-cooling system of the regenerative refrigerator in this embodiment include a two-stage GM refrigerator module and an expansion and compression module.

The secondary GM chiller module includes a regenerative chiller unit and a DC external circulation unit. The regenerative refrigerator unit includes compression device 1, compressor low-pressure air storage tank 2, compressor cooler and filter device 3, compressor high-pressure air storage tank 4, GM type compressor high and low pressure air distribution valve 5, refrigerator inlet. Air passage 6, refrigerator cylinder 7, first-stage expansion piston 11, first-stage regenerator 8, first-stage expansion piston sealing mechanism 9, first-stage expansion piston and cylinder gap 10, second-stage expansion piston 27 , the second-stage regenerator 26, the first-stage cold end heat exchanger 12, the first-stage expansion chamber 13, the second-stage expansion piston sealing mechanism 14, the gap 15 between the second-stage expansion piston and the cylinder, the second-stage cooling End heat exchanger 16 , second-stage expansion chamber 17 . The DC external circulation unit includes a DC 28 , a heat exchanger 24 , a distributed heat exchanger 30 , and a DC control valve 20 .

The expansion and compression module includes a small hole valve 29 and a low pressure buffer gas reservoir 31 , a compression mechanism 32 , a compression mechanism cooler and a filter device 33 .

The working process of this embodiment is:

Complete the system installation according to the above process, and fill in the gas working medium under the working pressure. Under the condition of room temperature, first set the opening of the small hole valve 29 to a certain degree, then start the compressor 1, and the refrigerator starts to cool down. When the temperature of the cold end heat exchanger 16 of the regenerator drops to the set temperature, the DC control valve 20 is adjusted. The valve controls the direct current flow, and starts the compression mechanism 32. The direct current flows through the heat exchanger 24 and the distributed heat exchanger 30 and is compressed to the original low pressure chamber pressure by the compression mechanism to form a stable cycle, and the heat exchanger 24 provides a node The cooling capacity at the back temperature of the flow, distributed cooling capacity is provided in the distributed heat exchanger 30 . The attached buffer gas storage 31 is stabilized at low pressure, and the compressor cooler and filter device 33 discharge the heat of compression, and filter and adsorb impurities. Adjust the DC control valve 20 and the compression mechanism 32, adjust the pressure of the DC gas between the small hole valve 29 and the compression mechanism 32 to the required value, and optimize to achieve a stable state.

Example 3

As shown in FIG. 3 , the high-efficiency pre-cooling system coupling the expansion mechanism and the regenerative refrigerator in this embodiment includes a single-stage Stirling refrigerator module, an expansion and compression module, and a liquid pre-cooling module.

Single-stage Stirling chiller modules include a regenerative chiller unit and a DC external circulation unit. The regenerative refrigerator unit includes a piston compression device 1, a compressor cooler 3, a refrigerator intake passage 6, a refrigerator cylinder 7, a first-stage expansion piston 11, a first-stage regenerator 8, and a first-stage expansion. The piston sealing mechanism 9 , the gap 10 between the first-stage expansion piston and the cylinder, the first-stage cold end heat exchanger 12 , and the first-stage expansion chamber 13 . The DC external circulation unit includes a DC 28 and a DC control valve 20 .

The expansion and compression module includes a turboexpander 29 and a low pressure buffer gas storage 31 (placed before the partition heat exchange), a compression mechanism 32 , a compression mechanism cooler and a filter device 33 .

The liquid precooling module includes a liquid source 21 , a liquid inlet control mechanism 22 , a liquid to be precooled 23 , a partition heat exchanger 30 , a cold end heat exchange component 24 , and a liquid collection component 25 , which are communicated in sequence.

The working process of this embodiment is:

Complete the system installation according to the above process, and fill in the gas working medium under the working pressure. The start-up conditions of the turbo-expander 29 are pre-set at room temperature, then the piston compressor 1 is operated, and the refrigerator starts to cool down. For the direct current control valve 20 and the valve of the feed control mechanism 22 , the liquid to be pre-cooled is continuously cooled through the partition heat exchanger 30 and the cold end heat exchange component 24 until it flows into the liquid collection component 25 . Adjust the valve of the DC control valve 20 and the feed control mechanism 22, control the DC flow and the flow rate of the liquid to be pre-cooled, and start the compression mechanism 32, and the DC flow through the partition heat exchanger is compressed to the original low-pressure chamber pressure by the compression mechanism 32, form a stable cycle. The attached buffer gas storage 31 is stabilized at low pressure, and the compressor cooler and filter device 33 discharge the heat of compression, and filter and adsorb impurities. Adjust the valve of the feed control mechanism 22 to adjust the pressure of the liquid to be pre-cooled; then adjust the DC control valve 20 and the compression mechanism 32, adjust the pressure of the DC gas between the turboexpander 29 and the compression mechanism 32 to the required value, and optimize Obtain a stable pre-cooling flow rate.

Example 4

As shown in FIG. 4 , the high-efficiency pre-cooling and liquefaction system coupling the expansion mechanism and the regenerative refrigerator of this embodiment includes a secondary pulse tube refrigerator module, an expansion and compression module, and a pre-cooling and liquefaction module.

The secondary pulse tube chiller module includes a regenerative chiller unit and a DC external circulation unit. The regenerative refrigerator unit includes compression device 1, compressor low-pressure air storage tank 2, compressor cooler and filter device 3, compressor high-pressure air storage tank 4, GM type compressor high and low pressure air distribution valve 5, refrigerator inlet. The gas channel 6, the first-stage regenerator 8, and the gas are divided into two paths in the first-stage regenerator 8, and the first path is connected to the first-stage cold-end connecting pipe 40 and the first-stage pulse tube cold-end heat exchanger in turn. 41. The first-stage pulse tube 42, the first-stage pulse tube hot-end heat exchanger 43, the first-stage phase modulation mechanism 44; the second path is connected to the first-stage cold-end heat exchanger 12 and the second-stage regenerator in sequence 26. Second stage cold end heat exchanger 16, second stage cold end connecting pipe 46, second stage pulse tube cold end heat exchanger 47, second stage pulse tube 48, second stage pulse tube hot end heat exchanger 49. The second-stage phase modulation mechanism 50.

The DC external circulation unit is divided into two circuits, including DC 28, regenerator side DC control valve 20 and a series of channels; the other DC includes DC 51 flowing to the pulse side, pulse side DC control valve 35 and a series of channels.

The expansion and compression module is divided into two paths, one path includes the piston expander 29 and the compression mechanism 32 ; the other path includes the capillary tube 52 and the compression mechanism 37 .

The pre-cooling and liquefaction module includes two channels, and the two channels have different working fluids to be pre-cooled and liquefied. One of them is the pre-cooling module on the regenerator side, including the gas source 21, the feeding control mechanism 22, the material to be pre-cooled 23, the partition heat exchanger 30, and the gas collection component 25, which are connected in sequence; the other is the pulse tube side liquefaction The module includes an air source 56 , an intake pressure control mechanism 57 , a material to be pre-cooled 58 , a partition heat exchanger 53 , a cold end heat exchange component 59 , and a liquid collection component 60 that are connected in sequence.

The working process of this embodiment is:

The working conditions of the piston expander 29 are set in advance at room temperature, the capillary tube 52 is manufactured according to the set geometric size, the system installation is completed according to the above process, and the gas working medium of the working pressure is filled. Then start the compressor 1, the refrigerator starts to cool down, and the temperature of the heat exchanger 16 at the cold end of the regenerator is lowered to below the liquefaction temperature of the working fluid on the pulse tube side.

For the pre-cooling module, open the DC control valve 20 and the valve of the feed control mechanism 22 , and the pre-cooled gas flows into the gas collection assembly 25 after passing through the partition wall heat exchanger 30 for pre-cooling. Adjust the valve of the DC control valve 20 and the feed control mechanism 22, control the DC flow and the flow of the gas to be pre-cooled, and start the compression mechanism 32, and the DC flow through the partition heat exchanger is compressed to the original low pressure chamber pressure by the compression mechanism 32, A stable circulation is formed, and the pressure of the gas to be pre-cooled is adjusted until a stable pre-cooling flow rate is obtained. Adjust the valve of the feed control mechanism 22 to adjust the pressure of the gas to be pre-cooled; then adjust the DC control valve 20 and the compression mechanism 32, and adjust the pressure of the DC gas between the piston expander 29 and the compression mechanism 32 to the required value, and optimize the Stable precooling flow rate.

For the liquefaction module, the flow control valve 35 and the valve of the feed control mechanism 57 are opened to allow flow through the partition heat exchanger 53 . The gas to be liquefied flows out of the gas source 56 , passes through the partition heat exchanger 53 and the cold end heat exchange component 59 and is continuously cooled until it flows into the liquid collection component 60 . Adjust the valve of the DC control valve 35 and the feed control mechanism 57, control the DC flow and the flow rate of the gas to be liquefied, and start the compression mechanism 37, and the DC flow through the partition heat exchanger is compressed to the original low-pressure chamber pressure by the compression mechanism 37, forming a Stable circulation, and adjust the pressure of the gas to be pre-cooled until a stable liquefaction rate is obtained. Adjust the valve of the feed control mechanism 57 to adjust the pressure of the gas to be liquefied; then adjust the DC control valve 35 and the compression mechanism 37, and adjust the pressure of the DC gas between the capillary 52 and the compression mechanism 37 to the required value until a stable liquefaction flow is obtained Rate.

The above description of the embodiments is for the convenience of those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (10)

1. A high-efficiency precooling and liquefaction system coupling expansion mechanism and regenerative refrigerator, is characterized in that, comprises regenerative refrigeration module, expansion and compression module and precooling and liquefaction module; The regenerative refrigeration module includes a regenerative refrigerator unit and a DC external circulation unit; The regenerative refrigerator unit comprises a compressor device (1), a regenerator, and a cold-end heat exchanger (12) connected in sequence; In the direct current external circulation unit, the direct current (28) leads out the refrigerator unit from any position, passes through a plurality of channels, and then returns to the regenerator to complete the direct current circulation; The DC external circulation unit is provided with a DC control valve (20), so as to control the size of the DC flow; The expansion and compression module includes an expansion mechanism arranged on the first temperature zone on the DC external circulation unit, a compression mechanism arranged on the second temperature zone on the DC external circulation unit, a buffer gas store, a compressor cooler and a filter device, The temperature of the second temperature region is higher than that of the first temperature region; The precooling and liquefaction module comprises a material source (21) of the material to be precooled, a feed control mechanism (22), a partition heat exchanger (30), a cold end heat exchange pipeline (24), and a cold end heat exchange pipeline (24), which are sequentially communicated. The material collection component (25), the material to be pre-cooled in the material source (21) is pre-cooled by the partition heat exchanger (30), and enters the cold material collection component (25). The device for liquefaction in the end heat exchange pipeline (24). 2. The high-efficiency pre-cooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 1, characterized in that, the position where the direct current (28) leads out of the regenerator structure is at the position of the regenerator. The cold end, or any position in the section between the cold end of the regenerator and the hot end of the regenerator; The position where the direct current (28) is introduced into the regenerative refrigerator system from the dividing wall heat exchanger is any section between the hot end of the regenerator to the compressor section and the section between the hot end of the regenerator and the cold end of the regenerator. Location; The direct current (28) is drawn out from one or more positions at the same time, thereby forming one direct current or multiple direct currents, and one or more partition heat exchangers are correspondingly provided on the direct current (28). 3. The high-efficiency pre-cooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 2, wherein the expansion mechanism is arranged on a direct current or on a plurality of direct currents respectively. ; The expansion mechanism is one of a single expansion mechanism, multiple expansion mechanisms connected in series, multiple expansion mechanisms connected in parallel, and multiple expansion mechanisms combined in series and parallel; The position of the expansion mechanism on the direct current is the cold end or any position between the cold end and the hot end. 4. A high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 3, wherein the expansion mechanism comprises a small hole valve, a small hole, a capillary pipe, a slit, One of the porous media to achieve throttling and pressure reduction through frictional resistance and local resistance; The expansion mechanism further includes a turbo expander and a piston expander; The buffer gas storage is arranged after the expansion mechanism, and the buffer gas storage is arranged at any position between the expansion mechanism and the compression mechanism. 5. A high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 1, wherein the compression mechanism is arranged on a direct current or on a plurality of direct currents respectively. ; The compression mechanism is one of a single compression mechanism, multiple compression mechanisms connected in series, multiple compression mechanisms connected in parallel, and multiple compression mechanisms combined in series and parallel. 6 . The high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 5 , wherein the position of the compression mechanism on the direct current is the hot end or the hot end to the cold end. 7 . any position in between; The compression mechanism is a volume-type supercharging mechanism or a turbine-type speed-type supercharging mechanism, and the volume-type supercharging mechanism is one of a piston type, a screw type, and a scroll type supercharging mechanism. 7. The high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 1, wherein the direct current (28) is introduced into the regenerator after being drawn out from the compression mechanism, or is introduced into the regenerator. The low-voltage components and high-voltage components are then introduced into the regenerator to form a cycle; The low-pressure component is a low-pressure pipeline of a valved compressor or a low-pressure cavity formed by setting a check valve in the pipeline of a valveless compressor and a valved compressor; The high-pressure component is a pipeline whose internal pressure is higher than a preset pressure threshold or a high-pressure chamber formed by matching a one-way valve on the pipeline. 8. The high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 1, wherein the regenerative refrigerator unit adopts regenerator components to realize heat exchange. Variable storage and release chillers; The regenerative refrigerator includes a hybrid structure in which one or more of a GM refrigerator, a Solvay refrigerator, a Stirling refrigerator, a VM refrigerator, and a pulse tube refrigerator are coupled in multiple stages; The pulse tube refrigerator is a GM type pulse tube refrigerator or a Stirling type pulse tube refrigerator. 9 . The high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 1 , wherein the regenerative refrigeration module is a regenerator built-in structure or a regenerator. 10 . External structure; In the regenerator built-in structure, the regenerator is built in the expansion piston; In the external structure of the regenerator, the expansion piston and the regenerator are arranged separately. 10. The high-efficiency precooling and liquefaction system coupling an expansion mechanism and a regenerative refrigerator according to claim 1, wherein the regenerative refrigeration module comprises a single-stage structure and a multi-stage coupling structure. The multi-level coupling structure includes a multi-level thermal coupling structure, a multi-level gas coupling structure, and a thermal coupling and gas coupling hybrid structure.

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