WO2020252689A1

WO2020252689A1 - Combined cycle room temperature refrigeration/heat pump double-effect system

Info

Publication number: WO2020252689A1
Application number: PCT/CN2019/091861
Authority: WO
Inventors: 余国瑶; 朱顺敏; 罗二仓; 戴巍; 吴张华
Original assignee: 中国科学院理化技术研究所
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2020-12-24

Abstract

A combined cycle room temperature refrigeration/heat pump double-effect system, comprising a linear compressor (1), a regenerative thermal unit (2) connected to the linear compressor (1) by means of a metal film (18), and a vapor compression throttling thermal unit (3) directly connected to the linear compressor (1) by means of a gas passage.

Description

A mixed cycle room temperature refrigeration/heat pump double-effect system

Technical field

This application relates to the field of refrigeration technology, and in particular to a hybrid cycle room temperature refrigeration/heat pump double-effect system.

Background technique

The high-temperature trans-heat pump/refrigeration double-effect system has a wide range of application requirements in transportation fields such as new energy vehicles, RVs, and heavy machinery, especially for pure electric vehicles. The high-efficiency and large-temperature trans-heat pump/refrigeration double-effect system is useful for improving winter travel in severe cold areas. Car comfort, improving energy consumption ratio, and reducing mileage anxiety play an important role. At present, traditional vapor compression throttling technology is still used in the above-mentioned application fields.

Vapor compression throttling technology is currently the most widely used and most mature technology in the field of small refrigeration technology. It uses an oil-lubricated compressor to compress the refrigerant. The refrigerant is used in throttling devices (such as capillary tubes, thermal expansion valves, and electronic expansion valves). The Joule-Thomson effect in) achieves cooling, which has the advantages of large cooling capacity and high efficiency. However, this technology faces challenges when working in heat pump mode. It is mainly reflected in the fact that the lower ambient temperature in winter will reduce the compressor intake, the compressor discharge temperature will increase, and the lubricant will age, which will seriously affect the heating efficiency and compression. The reliability of the machine. To solve this problem, the introduction of intermediate throttling and air jet enthalpy solves this problem, but it also significantly increases the complexity of the system and reduces the reliability.

The Stirling-type regenerative thermal unit driven by the linear compressor belongs to the category of traveling wave thermoacoustic heat engine, which uses the linear reciprocating motion of the oil-free piston to generate pressure waves, which causes the helium to produce a periodic expansion and compression process. Under the effect of phase modulation of the sound field of the ejector, the expansion and compression of helium gas realizes the conversion of sound energy to heat energy in the regenerator, thereby producing a refrigeration (pumping heat) effect. The regenerative thermal unit of the ejector phase modulation is based on the reversible Stirling cycle, so it has a theoretical efficiency equivalent to the Carnot efficiency. At the same time, its working temperature range is wide, the thermal efficiency is not affected by the ambient temperature, and it has the advantages of large temperature span, compact structure, low vibration and high reliability. However, because the room temperature temperature-regenerative Stirling cycle using helium as the working fluid has no phase change effect, it has the disadvantage of low energy density. Especially when working in cooling mode, the small temperature difference and compact structure limit the heat exchange effect. Its refrigeration efficiency and unit volume refrigeration capacity are far lower than vapor compression throttling technology.

Summary of the invention

(1) Technical problems to be solved

The purpose of this application is to provide a mixed-cycle room temperature refrigeration/heat pump double-effect system, which aims to solve the problem of reliability and high performance in the prior art.

(2) Technical solution

In order to solve the above technical problems, this application provides a hybrid cycle room temperature refrigeration/heat pump double-effect system, which includes at least one linear compressor and a regenerative thermal unit connected to the linear compressor through a metal film, and The linear compressor is directly connected to the vapor compression throttling thermal unit through the gas circuit.

Further, the vapor compression and throttling thermal unit includes a regenerative heat exchanger, a condensing heat exchanger, an electronic expansion valve, and an evaporative heat exchanger connected in sequence through a pipeline. The regenerative heat exchanger includes a first-stage regenerative heat exchanger and a second-stage regenerative heat exchanger.

Further, the regenerative heat unit includes a heat-absorbing end heat exchanger, a heat regenerator, a heat-releasing end heat exchanger, a compression cavity, an ejector support seat, an ejector and an expansion cavity, an ejector and an ejector support seat The cavity between forms a compression cavity, and the cavity between the ejector and the linear compressor forms an expansion cavity.

Further, the condensing heat exchanger of the vapor compression throttling thermal unit is thermally coupled with the heat release end heat exchanger of the regenerative thermal unit, and the evaporative heat exchanger and the regenerator of the vapor compression throttling thermal unit are thermally coupled. The heat exchanger at the end of the unit is thermally coupled.

Further, the linear compressor includes a compressor housing, a piston, a cylinder, a mover magnet, and a stator. The piston in the cylinder and the cavity at the bottom end of the cylinder form a back cavity of the linear compressor. The compressor housing and the cylinder A coil, a mover magnet and a stator are arranged between the linear compressor, the piston of the linear compressor is rigidly connected to the mover magnet, the cylinder is provided with a one-way valve, the one-way valve and the vapor compression throttling thermal unit gas Road connection.

Further, the size of the piston of the linear compressor near the regenerative heating unit is larger than the size of other parts of the piston, and the size of the inner wall of the cylinder near the regenerative heating unit is larger than the size of the other parts of the inner wall of the cylinder. The piston of the linear compressor matches the shape and size of the inner wall of the cylinder.

Further, the inner wall surface of the cylinder and the piston are both stepped, and the specific shape may be a "T" shape, or other shapes that meet the above requirements.

Further, the regenerative thermal unit includes an external heat exchange unit, and the heat exchanger of the regenerative thermal unit and the external heat exchange unit are thermally coupled, and there is no air circuit connection structure.

According to a preferred embodiment of the present application, the double-effect system includes two symmetrically arranged linear compressors, one of which is connected to the gas path of the vapor compression throttling thermal unit through a one-way valve controlled to open in the linear compressor , The other one is connected to the gas circuit of the vapor compression throttling thermal unit through the one-way valve that is controlled to open in the vapor compression throttling thermal unit, and the two sets are connected by a pipeline controlled by the one-way valve, and the two are symmetrically arranged The piston movement of the linear compressor is 180 degrees out of phase.

Further, the heat-absorbing end heat exchanger is close to the piston of the linear compressor, and the heat-releasing end heat exchanger is away from the piston of the linear compressor.

Further, the regenerative heating unit and the linear compressor are separated by a metal film, and the metal film has a sealing effect to prevent the gas working medium of the regenerative heating unit and the linear compressor from escaping from each other; The gas working medium in the thermal unit is helium or hydrogen.

Further, the material of the metal film is spring steel.

Further, the vapor compression and throttling thermal unit includes an exhaust one-way valve, a first-stage regenerative heat exchanger, a condensation heat exchange, a second-stage regenerative heat exchanger, an electronic expansion valve, and an evaporator, which are sequentially connected by pipes. Heat exchanger and suction check valve. The condensing heat exchanger is thermally coupled with the heat-releasing end heat exchanger of the regenerative thermal unit, and the evaporating heat exchanger is thermally coupled with the absorbing end heat exchanger of the regenerator thermal unit.

Further, a first suction check valve is provided between the first stage regenerative heat exchanger and the back cavity of the linear compressor, and a first suction check valve is provided between the first stage regenerative heat exchanger and the cavity of the linear compressor. An exhaust check valve. When there are two linear compressors arranged symmetrically, a second discharge check valve is provided in the chamber of the linear compressor provided with the first suction check valve, and the linear compressor is provided with the first discharge check valve. The back cavity of the compressor is provided with a second suction check valve, and the second discharge check valve is connected with the second suction check valve through a pipeline.

Further, the vapor compression throttling thermal unit is directly gas-coupled with the linear compressor, and the gas working medium is R134a, R410a, R407C and other environmentally friendly working mediums.

(3) Beneficial effects

Compared with the prior art, the above-mentioned technical solution of the present application has the following beneficial effects: the present application provides a hybrid cycle room temperature refrigeration/heat pump double-effect system, through the oil-free linear compressor, vapor compression throttling thermal unit, return The integration of thermal thermal units makes the reliability of the refrigeration/heat pump double-effect system of the present application and the unit volume refrigeration capacity significantly improved.

This application uses an oil-free linear compressor to generate periodic reciprocating pressure fluctuations, and transmits the pressure fluctuations to a Stirling-type regenerative thermal unit that uses helium or hydrogen as a working fluid through a metal film, and at the same time, the oil-free linear compression The one-way valve is used in the machine to generate high and low pressure gas, and the Joule-Thomson effect of the environmentally friendly refrigerant is used to produce a high power density refrigeration effect. The advantage of this technology lies in the use of a single compressor to simultaneously generate periodic alternating flow and high and low pressure driven one-way flow, making full use of the large temperature span, high compactness, high efficiency and high reliability of the Stirling cycle of the ejector phase modulation At the same time, it takes advantage of the high heat exchange energy density of the vapor compression throttling unit to form an oil-free lubrication, large temperature span, high-efficiency, compact and high-volume refrigeration/heat pump double-effect system at room temperature and temperature.

Description of the drawings

Fig. 1 is a schematic cross-sectional view of a mixed-cycle room temperature refrigeration/heat pump double-effect system according to Embodiment 1 of the application;

Fig. 2 is a schematic cross-sectional view of a mixed-cycle room temperature refrigeration/heat pump double-effect system of Example 2 of the present application.

Reference number

1- Linear compressor; 2- Regenerative thermal unit;

3-Vapor compression throttling thermal unit; 11-Back cavity;

12-Motor magnet; 13-Stator;

14-piston; 15-chamber;

16-Cylinder; 17-Compressor housing;

18-metal film; 21-expansion cavity;

22-heat-absorbing end heat exchanger; 23-ejector;

24-regenerator; 25-heat-exchanger;

26-Compression chamber; 27-Ejector support seat;

31-Condensing heat exchanger; 32-Second-stage regenerative heat exchanger;

33-Electronic expansion valve; 34-Evaporative heat exchanger;

35-The first stage regenerative heat exchanger; 36-The first suction check valve;

37-The first exhaust check valve; 38-The second suction check valve;

39-The second exhaust check valve.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

Example 1:

Figure 1 is a cross-sectional schematic diagram of a mixed-cycle room temperature refrigeration/heat pump double-effect system according to Embodiment 1 of the present application. As shown in Figure 1, a hybrid-cycle room temperature refrigeration/heat pump double-effect system provided by an embodiment of the present application includes: The compressor 1 and the recuperative thermal unit 2 connected to the linear compressor 1 through a metal film 18, and the vapor compression throttling thermal unit 3 directly connected to the linear compressor 1 through a gas path.

The linear compressor 1 includes a compressor housing 17, a piston 14, a cylinder 16, a mover magnet 12 and a stator 13. The piston 14 in the cylinder and the cavity at the bottom end of the cylinder form the back cavity 11 of the linear compressor 1. A gap seal or a labyrinth seal can be used between the piston 14 and the wall of the cylinder 16; the piston 14 can be supported by a gas bearing suspension or a plane spring.

The inner wall surface of the cylinder 16 and the piston 14 are both stepped (specifically T-shaped); the inner diameter of the upper end of the cylinder 16 is larger than the inner diameter of the lower end of the cylinder 16; the inner diameter of the upper end of the piston 14 is larger than the lower end of the piston 14 Inner diameter size.

The regenerative thermal unit includes an expansion cavity 21, a heat absorption end heat exchanger 22, a heat regenerator 24, a heat release end heat exchanger 25, a compression cavity 26, and an ejector support seat 27 and an ejector 23 connected in sequence The ejector 23 and the cavity at the top end of the cylinder 16 (ie, the cavity of the ejector 23 and the ejector support seat 27) form a compression chamber 6, and the cavity between the ejector 23 and the piston 14 (ie, the ejector 23 The cavity between the linear compressor and the linear compressor forms an expansion chamber 21.

The heat-absorbing end heat exchanger 22 is close to the piston 14 of the linear compressor 1, and the heat-releasing end heat exchanger 25 is far away from the piston 14 of the linear compressor 1.

The regenerative thermal unit 2 and the linear compressor 1 are separated by a metal film 18, the metal film 18 has a sealing effect to prevent the gas working medium of the regenerative thermal unit and the linear compressor from interfering with each other; The gas working medium in the thermal thermal unit is helium or hydrogen.

The material of the metal film 18 is spring steel.

The vapor compression and throttling thermal unit 3 includes an exhaust check valve 37, a first-stage regenerative heat exchanger 35, a condensing heat exchanger 31, a second-stage regenerative heat exchanger 32, and an electronic expansion, which are sequentially connected by pipes. Valve 33, evaporative heat exchanger 34, and suction check valve 36. The condensing heat exchanger 31 is thermally coupled to the heat-releasing end heat exchanger 25 of the recuperative thermal unit 2, and the evaporative heat exchanger 34 is thermally coupled to the heat-absorbing end heat exchanger of the regenerator thermal unit 2 22 Thermal coupling.

A first suction check valve 36 is provided between the first-stage regenerative heat exchanger 35 and the back cavity 11 of the linear compressor 1, which is between the first-stage regenerative heat exchanger 35 and the chamber 15 of the linear compressor 1. A first exhaust check valve 37 is provided in between.

The vapor compression throttling thermal unit 3 is directly gas-coupled with the linear compressor 1, and the gas working medium charged is R134a, R410a, R407C and other environmentally friendly working mediums.

The following specifically describes the working process of the room temperature temperature zone refrigeration/heat pump double-effect system provided in this embodiment:

During operation, the coil of the stator 13 of the linear compressor 1 is supplied with alternating current of a certain frequency, thereby generating an alternating magnetic field. The mover magnet 12 drives the piston 8 of the linear compressor to perform linear reciprocating motion under the action of the alternating magnetic field.

The working process of the regenerative thermal unit 2 is as follows:

The reciprocating motion of the piston 14 generates periodic pressure fluctuations in the expansion chamber 21, thereby pushing the ejector 23 to perform linear reciprocating motion. In a complete heat recovery cycle, when the piston 14 and the ejector 23 descend at the same time, the gas expands in the expansion chamber 21, the temperature decreases, and the heat is absorbed from the outside through the heat-absorbing end heat exchanger 22. For refrigerators, the heat-absorbing end heat exchanger 22 is the cold head, which is used for cooling; for heat pumps, the heat-absorbing end heat exchanger 22 is a room temperature heat exchanger, and the gas absorbs heat from room temperature to subsequently pump the heat to the high temperature end. . After that, the piston 14 goes down and the ejector 23 goes up. The gas flows from the expansion chamber 21 through the regenerator 24 into the compression chamber 26, and absorbs heat from the regenerator 24 on the way, and the temperature rises. Subsequently, the piston 14 and the ejector 23 move upward at the same time, so that the gas is compressed in the compression chamber 26 and releases heat to the outside through the heat-releasing end heat exchanger 25. For refrigerators, the exothermic end heat exchanger 5 is a room temperature heat exchanger, and the heat is released to the environment as waste heat; for a heat pump, the exothermic end heat exchanger 5 is a high temperature heat exchanger, and the heat is collected and utilized. Finally, the piston 14 goes down, and the ejector 23 goes up, allowing the gas to flow from the compression chamber 26 through the regenerator 24 into the expansion chamber 21, release heat to the regenerator 24 on the way, and reduce the gas temperature to complete a complete cycle. During the whole cycle, the piston and the ejector make a simple harmonic motion, and the phase of the former is ahead of the latter. It can be seen that the heat-absorbing end heat exchanger 22 close to the piston is the low temperature (room temperature) end, which avoids the increase in friction caused by the piston being close to the high temperature heat exchanger, which reduces the system efficiency and service life.

The working process of the vapor compression throttling thermal unit 3 is as follows:

When the linear compressor piston 14 is in the equilibrium position, the first exhaust check valve 37 and the first suction check valve 36 are both in a closed state; when the linear compressor piston 14 gradually moves upward, the back cavity 11 expands in volume and the pressure Gradually decrease; when the linear compressor piston 14 reaches the top of the stroke, the gas pressure in the back chamber 11 reaches the lowest value, and the valve plate of the first suction check valve 36 opens against the spring force under the action of the pressure difference on both sides , Inhale the gas of the vapor compression and throttling thermal unit 3 into the back cavity 11. When the piston 14 of the linear compressor reaches the top of the stroke, the piston 14 starts to move downwards, thereby starting to compress the gas in the chamber 15. At this time, the gas pressure in the back chamber 11 gradually rises, and the first suction check valve 36 The valve plate is closed under pressure and spring force. When the linear compressor piston 14 reaches the bottom end of the stroke, the gas pressure in the chamber 15 reaches the maximum value. At this time, the valve plate of the first exhaust check valve 37 opens under the action of the pressure difference on both sides against the spring force. The compressed high-pressure gas is discharged through the first exhaust check valve 37 and enters the vapor compression and throttling thermal unit 3 through the pipeline. When the linear compressor piston 14 reaches the bottom end of the stroke, the piston 14 starts to move upward, the gas in the chamber 15 begins to expand, the pressure gradually decreases, and the valve plate of the exhaust check valve 37 is closed under the action of pressure and spring force. . Start the next cycle of expansion-suction-compression-exhaust-expansion.

After the compressed high-pressure gas enters the vapor compression throttling thermal unit 3, it first enters the first-stage regenerative heat exchanger 35 to exchange heat with the returned low-temperature and low-pressure gas. After that, it enters the condensing heat exchanger 31 and releases heat to the environment medium. For the refrigerator, the heat is released to the environment through the condensation heat exchanger 31 as waste heat; for the heat pump, the heat is collected and used through the condensation heat exchanger 31. In the condensing heat exchanger 31, the high-temperature and high-pressure gas working fluid is condensed into a saturated liquid state and enters the second-stage regenerative heat exchanger 32, and exchanges heat with the low-temperature and low-pressure gas flowing out of the evaporative heat exchanger 34 to further cool down. Then it enters the electronic expansion valve 33, adiabatic throttling and reducing the temperature and pressure to the wet saturated vapor state, and then enters the evaporative heat exchanger 34 for constant-pressure vaporization to absorb heat, and then flows through the second stage regenerative heat exchanger 32 and the first stage in turn The regenerative heat exchanger 35 returns to the linear compressor 1 to start the next cycle.

Example 2:

2 is a cross-sectional schematic diagram of a mixed-cycle room temperature refrigeration/heat pump double-effect system according to Embodiment 2 of the present application. As shown in FIG. 2, a hybrid-cycle room temperature refrigeration/heat pump double-effect system provided by an embodiment of the present application includes two A symmetrically arranged linear compressor 1, and a regenerative thermal unit 2 connected to the two linear compressors 1 through a metal film 18, and a vapor compression throttling directly connected to the two linear compressors 1 through a gas path Thermal unit 3.

The two linear compressors 1 have exactly the same structural parameters and are arranged symmetrically. This arrangement can make the two motor power pistons move 180 degrees out of phase, thereby completely offsetting the vibration of the housing caused by the motor power piston.

The material of the metal film 18 is spring steel.

The vapor compression and throttling thermal unit 3 includes a first suction check valve 36, a first exhaust check valve 37, a second suction check valve 38, a second exhaust check valve 39, and a One-stage regenerative heat exchanger 35, condensation heat exchanger 31, second-stage regenerative heat exchanger 32, electronic expansion valve 33, and evaporative heat exchanger 34. The condensing heat exchanger 31 is thermally coupled to the heat-releasing end heat exchanger 25 of the recuperative thermal unit 2, and the evaporative heat exchanger 34 is thermally coupled to the heat-absorbing end heat exchanger of the regenerator thermal unit 2 22 Thermal coupling.

A first suction check valve 36 is provided between the first-stage regenerative heat exchanger 35 and the back cavity 11 of the right linear compressor 1. The first-stage regenerative heat exchanger 35 and the left linear compressor 1 A first exhaust check valve 37 is provided between the chambers 15. Between the chamber 15 of the right linear compressor 1 and the back chamber 11 of the left linear compressor 1, a second discharge check valve 39 and a second suction check valve 38 are arranged in sequence, and a second discharge check valve 39 It is connected to the second suction check valve 38 through a pipeline.

The working principle of the second embodiment is the same as that of the first embodiment, the difference is that the low-temperature and low-pressure gas flowing back from the vapor compression throttling thermal unit 3 is sucked by the first suction check valve 36, and then passes through the right linear compressor and the left linear compressor in turn. After the compressor is compressed in two stages (specifically, after being compressed by the right linear compressor, it is discharged through the second discharge check valve 39, and then enters the left linear compressor through the second suction check valve 38 for secondary compression) , It is discharged through the first exhaust check valve 37 and enters the vapor compression and throttle thermal unit 3 again. Compared with Embodiment 1, Embodiment 2 has lower vibration and noise, and higher system efficiency.

This application is based on a single compressor to realize a large temperature zone heat pump and a high specific power room temperature refrigeration cycle, a single oil-free linear compressor is used to generate periodic reciprocating pressure fluctuations, and a check valve is used to generate high and low pressure gas. The fluctuating pressure is driven by the metal membrane to drive the regenerative thermal unit using helium as the working medium to achieve a large temperature span and high-efficiency heat pump heating effect up to 70℃ or more, and its thermal efficiency is not affected by the low temperature environment; high and low pressure gas formed by a one-way valve It can take advantage of the large cooling capacity of the vapor compression throttling effect of the environmentally friendly working fluid to form a room temperature cooling/heat pump double-effect system with high efficiency and high energy density.

Any content not specified in this application can adopt conventional technical knowledge in this field. For example, the arrangement of the mover magnet, stator, piston, etc. of the linear compressor in the present application, the arrangement of the heat-absorbing end heat exchanger, regenerator, and radiating end heat exchanger of the regenerative thermal unit.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the application has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solution of the application does not depart from the spirit and scope of the technical solution of the application, and should be covered by the application. The scope of the claims.

Claims

A hybrid cycle room temperature refrigeration/heat pump double-effect system, characterized in that the double-effect system includes at least one linear compressor and a regenerative thermal unit connected to the linear compressor through a metal film, and is connected to the linear compressor. The compressor is directly connected to the vapor compression throttling thermal unit through the gas circuit.
The hybrid cycle room temperature refrigeration/heat pump double-effect system according to claim 1, wherein the vapor compression throttling thermal unit includes a heat recovery heat exchanger, a condensation heat exchanger, an electronic expansion valve and Evaporative heat exchanger.
The mixed-cycle room temperature refrigeration/heat pump double-effect system according to claim 1 or 2, wherein the regenerative thermal unit includes a heat-absorbing end heat exchanger, a heat regenerator, a heat-releasing end heat exchanger, and a compressor The cavity, the ejector supporting seat, the ejector and the expansion cavity, the cavity between the ejector and the ejector supporting seat forms a compression cavity, and the cavity between the ejector and the linear compressor forms an expansion cavity.
The hybrid cycle room temperature refrigeration/heat pump double-effect system according to claim 3, wherein the condensation heat exchanger of the vapor compression throttling thermal unit is thermally coupled with the heat release end heat exchanger of the regenerative thermal unit, The evaporative heat exchanger of the vapor compression and throttling thermal unit is thermally coupled with the heat-absorbing end heat exchanger of the regenerator thermal unit.
The hybrid cycle room temperature refrigeration/heat pump double-effect system according to any one of claims 1-4, wherein the linear compressor includes a compressor housing, a piston, a cylinder, a mover magnet and a stator, and the The piston and the cavity at the bottom end of the cylinder form the back cavity of the linear compressor. A coil, mover magnet and stator are arranged between the compressor housing and the cylinder. The piston of the linear compressor is rigidly connected to the mover magnet. The cylinder is provided with a one-way valve, and the one-way valve is connected with the gas path of the vapor compression throttling thermal unit.
The hybrid cycle room temperature refrigeration/heat pump double-effect system according to claim 5, wherein the size of the piston of the linear compressor near the regenerative thermal unit is larger than the size of other parts of the piston, and the inner wall of the cylinder is near the return The size of the thermal unit is larger than the size of other parts of the inner wall of the cylinder, and the piston of the linear compressor matches the shape and size of the inner wall of the cylinder.
The mixed-cycle room temperature refrigeration/heat pump double-effect system according to claim 5 or 6, wherein the inner wall surface of the cylinder and the piston are both stepped.
The mixed cycle room temperature refrigeration/heat pump double-effect system according to any one of claims 1-7, wherein the regenerative thermal unit comprises an external heat exchange unit, and the heat exchanger of the regenerative thermal unit It is thermally coupled with the external heat exchange unit.
The mixed-cycle room temperature refrigeration/heat pump double-effect system according to any one of claims 1-8, wherein the double-effect system comprises two symmetrically arranged linear compressors, one of which passes into the linear compressor The one-way valve that is controlled to open is connected to the gas path of the vapor compression throttling thermal unit, and the other one is connected to the gas path of the vapor compression throttling thermal unit by controlling the open one-way valve into the vapor compression throttling thermal unit. Two sets They are connected by a pipeline controlled by a one-way valve, and the piston movement phases of the two symmetrically arranged linear compressors are 180 degrees apart.
The mixed-cycle room temperature refrigeration/heat pump double-effect system according to any one of claims 1-9, wherein the gas working medium charged by the vapor compression throttling thermal unit is R134a, R410a or R407C, and the return The gas working medium in the thermal thermal unit is helium or hydrogen, and the material of the metal film is spring steel.