CN117029324A

CN117029324A - Refrigerant recovery system and control method

Info

Publication number: CN117029324A
Application number: CN202310925183.7A
Authority: CN
Inventors: 史贺纯; 钟权; 李华杰; 黄宇杰; 吴敏庭; 赵桓
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2023-07-26
Filing date: 2023-07-26
Publication date: 2023-11-10

Abstract

The invention relates to the field of a first compressor, in particular to a refrigerant recovery system and a control method, wherein a mixing tank is used for storing a refrigerant to be recovered; a first heat exchanger having a first pass and a second pass coupled to each other; the inlet of the first passage is communicated with the outlet of the mixing tank; a first compressor having an inlet in communication with an outlet of the first passage; the inlet of the separation device is communicated with the outlet of the first compressor; the separation device comprises a first outlet and a second outlet, the second passage easily-adsorbed component is discharged from the first outlet, the difficultly-adsorbed component is discharged from the second outlet, and part of heat of the difficultly-adsorbed component discharged from the second outlet is used for heating the refrigerant flowing through the first passage; a first storage means for storing the adsorbable component discharged from the first outlet; and the second storage device is used for storing the components which are discharged from the second outlet and difficult to adsorb, so that the heat generated in the adsorption separation process is effectively utilized, and the separation efficiency is improved.

Description

Refrigerant recovery system and control method

Technical Field

The invention relates to the field of first compressors, in particular to a refrigerant recovery system and a control method.

Background

Hydrofluorocarbon refrigerants have very high Global Warming Potential (GWP) and they will be phased out for the next decades. The high GWP refrigerant is recovered and reused, which can minimize the influence of the refrigerant on the environment and contribute to the prevention of ozone depletion and global warming. Among them, the separation and purification of mixed refrigerants is one of the main challenges of refrigerant recovery and purification systems, especially the separation and purification of azeotropic or near-azeotropic refrigerants. Due to their close boiling points, conventional separation methods such as distillation are not feasible. Various techniques have been developed for separating mixed refrigerants including extractive distillation using ionic liquids, membrane separation, adsorption, and the like. However, extractive distillation requires the introduction of additional organic entrainers, and membrane separation requires high membrane materials, which can further complicate the separation process. The adsorption separation technology has low cost, high separation purity and great application prospect.

Adsorption separation processes used in industry include temperature swing adsorption, pressure swing adsorption, rinse adsorption, displacement adsorption, and the like. The pressure swing adsorption process is carried out by adsorbing at a higher pressure, desorbing at a lower pressure, and completing the cycle by utilizing the difference of the partial pressures of the adsorbents. Since the pressure changes are much faster than the other parameters and no additional desorbent, rinse agent, has to be introduced into the process, the apparatus is relatively simple and the energy consumption is low.

The adsorption separation process can generate heat absorption and heat release, specifically, adsorption heat release and desorption heat absorption; in the gas adsorption separation process, the adsorption heat is large, and the adsorption process can lead to the temperature rise of the gas which is not adsorbed; the heat of adsorption is not effectively utilized, which is unfavorable for energy conservation.

Aiming at the technical problems, no better solution exists at present.

Disclosure of Invention

In order to effectively utilize heat generated in the adsorption separation process and improve the separation efficiency, a refrigerant recovery system and a control method are provided.

The invention provides a refrigerant recovery system for separating easily-adsorbable components from difficultly-adsorbable components in a refrigerant, comprising:

a mixing tank for storing a refrigerant to be recovered;

a first heat exchanger having a first pass and a second pass coupled to each other; the inlet of the first passage is communicated with the outlet of the mixing tank;

a first compressor having an inlet in communication with an outlet of the first passage;

a separation device having an inlet in communication with an outlet of the first compressor; the separation device comprises a first outlet and a second outlet, the second passage is provided with the easily adsorbed component discharged from the first outlet, the difficultly adsorbed component is discharged from the second outlet, and part of heat of the difficultly adsorbed component discharged from the second outlet is used for heating the refrigerant flowing through the first passage;

A first storage means for storing the adsorbable component discharged from the first outlet;

and a second storage means for storing the hardly adsorbed component discharged from the second outlet.

Preferably, the separation device comprises a first separation tank and a second separation tank;

the first separation tank and the second separation tank are of a double-layer shell structure;

the cavity between the double-layer shells of the first separation tank is a first interlayer, and the inner cavity of the first separation tank is a first inner cavity; the cavity between the double-layer shells of the second separation tank is a second interlayer, and the inner cavity of the second separation tank is a second inner cavity;

the outlet of the first compressor is selectively communicated with the first interlayer and the second interlayer, and adsorbents are arranged in the first inner cavity and the second inner cavity.

Preferably, a first control valve is arranged on a pipeline connected between the outlet of the first compressor and the inlet of the first interlayer, a second control valve is arranged on a pipeline connected between the outlet of the first compressor and the inlet of the second interlayer, a third control valve is arranged on a pipeline connected between the outlet of the first interlayer and the inlet of the second inner cavity, and a fourth control valve is arranged on a pipeline connected between the outlet of the second interlayer and the inlet of the first inner cavity.

Preferably, the first storage device comprises a vacuum pump, a tenth control valve is arranged on a pipeline between an air inlet of the vacuum pump and an air inlet of the first inner cavity, and an eleventh control valve is arranged on a pipeline between the air inlet of the vacuum pump and the air inlet of the second inner cavity;

the separation device comprises an outlet valve group, and the components difficult to adsorb, which are discharged from the first separation tank and the second separation tank, are discharged to the second storage device after passing through the outlet valve group.

Preferably, a fifth control valve is arranged on a pipeline between the outlet of the first inner cavity and the inlet of the second passage, and a sixth control valve is arranged on a pipeline between the outlet of the second inner cavity and the inlet of the second passage.

Preferably, the refrigerant recovery system is further provided with a second heat exchanger, and the second heat exchanger comprises a third passage and a fourth passage;

an eighth control valve is arranged on a pipeline between the outlet of the first inner cavity and the inlet of the third passage, and a ninth control valve is arranged on a pipeline between the outlet of the second inner cavity and the inlet of the third passage;

the fourth passage is communicated with the second passage through a refrigerant circulating pipeline, a second compressor is arranged on the refrigerant circulating pipeline, the outlet of the second compressor is communicated with the inlet of the second passage, and the inlet of the second compressor is communicated with the outlet of the fourth passage.

Preferably, an expansion valve is disposed on the refrigerant circulation line between the outlet of the second passage and the inlet of the fourth passage.

Preferably, a seventh control valve is arranged on the pipeline between the outlet of the first inner cavity and the outlet of the second inner cavity.

The invention also provides a control method for the refrigerant recovery system, which comprises the following steps:

step one: the second control valve, the fourth control valve and the eleventh control valve are controlled to be opened, the outlet valve group is controlled to be closed, and the vacuum pump is controlled to be started;

controlling the first step to keep a first preset time period, and then executing the next step;

step two: controlling the outlet valve group to be in a first mode, closing other control valves, and controlling the vacuum pump to stop; the non-adsorbable component within the first lumen is discharged from the first lumen when the outlet valve set is in the first mode; controlling the second step to keep a second preset time period, and then executing the next step;

step three: controlling the outlet valve group to be in a second mode, closing other control valves, and controlling the vacuum pump to stop; when the outlet valve bank is in the first mode, the first inner cavity and the second inner cavity are communicated;

Controlling the third step to keep a third preset time length, and then executing the next step;

step four: the first control valve, the third control valve and the tenth control valve are controlled to be opened, the outlet valve group is controlled to be closed, and the vacuum pump is controlled to be opened;

controlling the fourth step to keep a fourth preset time length, and then executing the next step;

step five: controlling the outlet valve group to be in a third mode, and closing other control valves; the non-adsorbable component within the second lumen is discharged from the second lumen when the outlet valve set is in the third mode;

controlling the fifth step to keep a fifth preset time period, and then executing the next step;

step six: controlling the outlet valve group to be in a second mode, and closing other control valves;

controlling the sixth step to keep a sixth preset time period, and then executing the first step;

and so on.

Preferably:

when the refrigerant recovery system is provided with a second compressor, when the refrigerant recovery system is in the step one, the second compressor is also controlled to start and last for the first preset time period; and when the refrigerant recovery system is in the fourth step, the second compressor is also controlled to start for the fourth preset time period.

According to the invention, the refrigerant entering the first compressor is heated by the components which are difficult to adsorb and are discharged from the separation device, so that the temperature and the pressure of the refrigerant discharged by the first compressor are improved, and on one hand, the desorption efficiency is improved by heating the components which are easy to adsorb by high temperature; on the other hand, the high-pressure refrigerant is favorable for the easily-adsorbed components to be adsorbed by the adsorbent, so that the recovery rate of the mixed refrigerant and the energy utilization rate of the process are improved. .

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those skilled in the art from this disclosure that the drawings described below are merely exemplary and that other embodiments may be derived from the drawings provided without undue effort.

The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the ambit of the technical disclosure.

FIG. 1 is a schematic diagram of a refrigerant recovery system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a refrigerant recovery system according to an embodiment of the present invention.

The reference numerals are expressed as:

1. a first separation tank; 101. a first interlayer; 102. a first lumen; 2. a second separation tank; 201. a second interlayer; 202. a second lumen; 3. a mixing tank; 401. a first heat exchanger; 402. a second heat exchanger; 4011. a first passage; 4012. a second passage; 4021. a third passage; 4022. a fourth passage; 501. a first compressor; 502. a second compressor; 601. a first control valve; 602. a second control valve; 603. a third control valve; 604. a fourth control valve; 605. a fifth control valve; 606. a sixth control valve; 607. a seventh control valve; 608. an eighth control valve; 609. a ninth control valve; 610. a tenth control valve; 611. an eleventh control valve; 7. a refrigerant circulation line; 701. an expansion valve; 8. a vacuum pump; 901. a flash tank; 902. an oil separator; 903. a first impurity storage tank; 904. a second impurity storage tank; 905. a first stop valve; 906. a second shut-off valve; 907. a first buffer tank; 908. a second buffer tank; 909. a gas-liquid separator; 910. an electromagnetic valve; 911. a first check valve; 912. a second check valve; 913. a first recovery vessel; 914. a first condenser; 915. a second condenser; 916. a first fan; 917. a second fan; 918. a second recovery vessel; 919. and (5) drying the filter.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly indicates otherwise.

Furthermore, it will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components, and/or groups thereof; the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a product or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such product or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a commodity or system comprising such elements.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present invention, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present invention; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, it should be noted that the terms "first", "second", etc. are used to define the components, which are merely for convenience in distinguishing the corresponding components, and not in order; unless otherwise stated, the words are not specifically defined and therefore should not be construed as limiting the scope of the invention.

In order to solve the above technical problems, a refrigerant recovery system and a control method are provided. In order to effectively utilize heat generated in the adsorption separation process, the separation efficiency is improved.

The present invention provides a refrigerant recovery system for separating easily adsorbable components from difficultly adsorbable components in a refrigerant, as shown in fig. 1-2, comprising:

a mixing tank 3 for storing a refrigerant to be recovered;

a first heat exchanger 401 having a first path 4011 and a second path 4012 coupled to each other; the inlet of the first passage 4011 communicates with the outlet of the mixing tank 3;

A first compressor 501, the inlet of which communicates with the outlet of the first passage 4011;

a separation device, the inlet of which communicates with the outlet of the first compressor 501; the separation device comprises a first outlet from which the easily adsorbable component is discharged from the second passage 4012 and a second outlet from which the hardly adsorbable component is discharged, a portion of the heat of the hardly adsorbable component discharged from the second outlet being used to warm the refrigerant flowing through the first passage 4011;

The terms "hardly adsorbable component" and "easily adsorbable component" as used in the claims and specification refer to relative terms. For different refrigerants, different adsorbents are required to adsorb the components which are easy to adsorb in the refrigerants, correspondingly, the gases which are difficult to adsorb by the adsorbents are the components which are difficult to adsorb, the components which are easy to adsorb and correspond to the different adsorbents are different, and the adsorbents are required to be determined according to the refrigerants to be separated.

The adsorption affinity of the adsorbent to different components of the mixed refrigerant is different to realize separation, and the adsorbent in the inner cavity can be activated carbon, zeolite or metal organic framework material. For azeotropic/near-azeotropic refrigerant, the adsorbent has strong adsorption capacity on one component of the azeotropic/near-azeotropic refrigerant, is a component easy to adsorb, and is obtained by desorption when vacuumizing a separation tank.

The term "lumen" as used herein includes "first lumen 102 and second lumen 202"; "separator tank" includes "first separator tank and second separator tank"; "interlayer" includes "first interlayer 101 and second interlayer 201"; "coupled to each other" in the present application refers to a connection that is capable of "heat exchange".

"part of the heat of the hardly adsorbable component discharged from the second outlet is used to raise the temperature of the refrigerant flowing through the first heat exchanger 401" includes that the hardly adsorbable component directly flows through the first heat exchanger 401, and the refrigerant flowing through the first heat exchanger 401 is heated and raised in a coupled manner; also included is the heating of the less adsorbable component first to a medium that in turn heats up the refrigerant flowing through the first heat exchanger 401.

In addition, the adsorbent can adsorb easily adsorbed components in the refrigerant, the easily adsorbed components are adsorbed by the adsorbent, and the difficultly adsorbed components cannot be adsorbed and discharged, so that the separation of the easily adsorbed components and the difficultly adsorbed components is completed, and the process is the prior art. When the concentration of the refrigerant to be adsorbed is fixed, the lower the temperature and the higher the pressure, the higher the adsorption capacity (the faster the adsorption time, the more the adsorption amount) of the adsorbent; conversely, the higher the temperature, the lower the pressure, and the smaller the adsorption capacity of the adsorbent (the slower the adsorption time, the smaller the adsorption amount). That is, the temperature and pressure are reduced to facilitate the adsorption process, and the temperature and pressure are increased to facilitate the desorption process; and because the adsorption heat of the components is large and the specific heat capacity is small, the adsorbent releases heat outwards when adsorbing the components easy to adsorb, so that the temperature of the components difficult to adsorb is increased.

Since the higher the temperature of the refrigerant gas entering the first compressor 501, the higher the temperature and pressure of the discharged refrigerant gas. Therefore, when the refrigerant recovery system works, the high-temperature and high-pressure refrigerant compressed by the first compressor 501 contacts with the adsorbent in the separation device, the easily-adsorbed component is adsorbed by the adsorbent and releases heat into the difficultly-adsorbed component, the difficultly-adsorbed component is discharged from the second outlet, and the easily-adsorbed component is separated from the adsorbent and is discharged from the first outlet; wherein, as the easily adsorbed component releases heat in the adsorption process, the temperature of the difficultly adsorbed component is increased, the second passage 4012 of the first heat exchanger 401 of the difficultly adsorbed component after temperature increase heats the refrigerant flowing through the first passage 4011, and the temperature of the refrigerant before entering the first compressor 501 is increased, thereby being beneficial to improving the working efficiency of the first compressor 501 and the temperature and pressure of the gas discharged by the first compressor 501; the method is equivalent to recovering the heat in the components difficult to adsorb, reduces the heat waste, is favorable for reducing the separation cost of the refrigerant, is favorable for reducing the energy consumption, improves the separation efficiency of the refrigerant, and improves the utilization rate of energy.

The recovered refrigerant is a single working medium, and the refrigerant with the single working medium can be reused, so that the reuse rate of the refrigerant is improved, and the cost is reduced.

The first compressor 501 is preferably an oil-free compressor, avoiding recontamination of the refrigerant to be separated by the oil of the first compressor 501.

The addition of the second buffer tank 908 after the first compressor 501 reduces pressure fluctuations in the system, allowing the refrigerant gas exiting the first compressor 501 to enter the next device smoothly.

the first separation tank 1 and the second separation tank 2 are of a double-layer shell structure;

the cavity between the double-layer shells of the first separation tank 1 is a first interlayer 101, and the inner cavity of the first separation tank 1 is a first inner cavity 102; the cavity between the double-layer shells of the second separation tank 2 is a second interlayer 201, and the inner cavity of the second separation tank 2 is a second inner cavity 202;

the outlet of the first compressor 501 is selectively communicated with the first interlayer 101 and the second interlayer 201, and the first inner cavity 102 and the second inner cavity 202 are respectively provided with an adsorbent.

Through designing the knockout drum as double-deck shell structure, the high temperature high pressure gas of first compressor 501 exhaust gets into first intermediate layer 101 or second intermediate layer 201 earlier and heats the refrigerant in first inner chamber 102 and the second inner chamber 202, so set up, compare in the current internal chamber internal portion of establishing the replacement heat pipe, the high temperature high pressure gas of being discharged by first compressor 501 gets into the heat exchange tube earlier, the application sets up double-deck shell structure, high temperature high pressure gas gets into the intermediate layer and can carry out more even heating to the inner chamber, because the inner chamber is wrapped up by outside intermediate layer, intermediate layer self structure also constitutes the insulating layer, and then guaranteed the stability of the refrigerant temperature in the inner chamber, the effectual desorption efficiency of easily adsorbed component from the adsorbent that has improved.

In addition, the sandwich structure does not occupy the inner cavity space of the separation tank, so that the inner cavity can be provided with enough adsorbent, a large amount of refrigerant can be charged into the inner cavity at one time, and the separation efficiency of the refrigerant is improved.

Moreover, the double-layer shell has simple structure, convenient manufacture, low price and convenient cleaning and maintenance.

Preferably, a first control valve 601 is disposed on a pipe connected between the outlet of the first compressor 501 and the inlet of the first interlayer 101, a second control valve 602 is disposed on a pipe connected between the outlet of the first compressor 501 and the inlet of the second interlayer 201, a third control valve 603 is disposed on a pipe connected between the outlet of the first interlayer 101 and the inlet of the second inner cavity 202, and a fourth control valve 604 is disposed on a pipe connected between the outlet of the second interlayer 201 and the inlet of the first inner cavity 102.

By setting the first control valve 601, the second control valve 602, the third control valve 603 and the fourth control valve 604, the first separation tank and the second separation tank 2 can alternately perform adsorption and desorption of the easily adsorbed components, and the separation efficiency of the refrigerant is improved.

The cooperation between the first separation tank and the second separation tank 2 is as follows:

the first stage: the first inner cavity 102 of the first separation tank 1 is used for adsorption, the second inner cavity 202 of the second separation tank 2 is used for desorption, the second control valve 602 and the fourth control valve 604 are opened, the first control valve 601 and the third control valve 603 are closed, the high-temperature and high-pressure gas discharged by the first compressor 501 enters the second interlayer 201 to heat the second inner cavity 202, the adsorbent in the second inner cavity 202 after the adsorption is heated is desorbed, and the easily adsorbed components are discharged after being desorbed; the refrigerant heated by the second inner cavity 202 becomes low-temperature high-pressure refrigerant, the low-temperature high-pressure refrigerant enters the first inner cavity 102 through the fourth control valve 604, and the easily-adsorbed components in the low-temperature high-pressure refrigerant entering the first inner cavity 102 are adsorbed by the adsorbent in the first inner cavity 102, so that the adsorption efficiency of the easily-adsorbed components in the first inner cavity 102 is improved, and the separation efficiency of the easily-adsorbed components and the difficultly-adsorbed components is improved due to the low-temperature high-pressure favorable for the adsorption process. After the easily-adsorbed components are adsorbed, the difficultly-adsorbed components are enriched in the gas phase, and the enriched difficultly-adsorbed components are discharged.

And a second stage: the second inner cavity 202 of the second separation tank 2 is used for adsorption, the first inner cavity 102 of the first separation tank 1 is used for desorption, the second control valve 602 and the fourth control valve 604 are closed, the first control valve 601 and the third control valve 603 are opened, the high-temperature and high-pressure gas discharged by the first compressor 501 enters the first interlayer 101 to heat the first inner cavity 102, the adsorbent in the first inner cavity 102 after the adsorption work is heated is desorbed, and the easily adsorbed components are discharged after being desorbed; the refrigerant heated in the first inner cavity 102 becomes low-temperature high-pressure refrigerant, the low-temperature high-pressure refrigerant enters the second inner cavity 202 through the third control valve 603, the easily-adsorbed components in the low-temperature high-pressure refrigerant entering the second inner cavity 202 are adsorbed by the adsorbent in the second inner cavity 202, the difficultly-adsorbed components are enriched in the gas phase, and the enriched difficultly-adsorbed components are discharged.

Then, the first stage work is performed again, and the cyclic work is performed in such a way that the first separation tank 1 and the second separation tank 2 alternately perform adsorption and desorption, thereby improving the separation efficiency of the gas.

Preferably, the first storage device includes a vacuum pump 8, a tenth control valve 610 is disposed on a pipeline between an air inlet of the vacuum pump 8 and an air inlet of the first inner cavity 102, and an eleventh control valve 611 is disposed on a pipeline between an air inlet of the vacuum pump 8 and an air inlet of the second inner cavity 202;

the separation device comprises an outlet valve group, and the components difficult to adsorb, which are discharged from the first separation tank 1 and the second separation tank 2, are discharged to the second storage device after passing through the outlet valve group.

Because the high temperature and the low pressure are favorable for desorption, when the desorption work is carried out, the high temperature and the high pressure gas compressed by the first compressor 501 is injected into the first interlayer 101 or the second interlayer 201, the vacuum pump 8 is arranged to vacuumize the first inner cavity 102 or the second inner cavity 202 to reduce the pressure of the inner cavity, so that the desorption efficiency of the easily adsorbed components from the adsorbent is improved; and the vacuum pump 8 also plays a role in driving airflow, so that the speed of desorbed gas flowing out of the inner cavity is accelerated, and the recovery and storage efficiency of the desorbed components is improved.

When the adsorbable component of the first interior chamber 102 is desorbed from the adsorbent, the tenth control valve 610 is opened, the eleventh control valve 611 is closed, and the vacuum pump 8 draws a vacuum from the first interior chamber 102; when the adsorbable component of the second lumen 202 is desorbed from the adsorbent, the tenth control valve 610 is closed and the eleventh control valve 611 is opened, and the vacuum pump 8 draws a vacuum from the second lumen 202.

Preferably, as shown in fig. 2, a fifth control valve 605 is disposed on a pipe between the outlet of the first inner chamber 102 and the inlet of the second passageway 4012, and a sixth control valve 606 is disposed on a pipe between the outlet of the second inner chamber 202 and the inlet of the second passageway 4012.

Embodiment one in which the gas before entering the first compressor 501 is heated:

at this time, the outlet valve group includes a fifth control valve 605 and a sixth control valve 606. When the first internal cavity 102 discharges the difficultly adsorbed component, the fifth control valve 605 is opened, and the sixth control valve 606 is closed; when the second inner cavity 202 discharges the difficultly adsorbed component, the fifth control valve 605 is closed, and the sixth control valve 606 is opened, so that the first inner cavity 102 and the second inner cavity 202 alternately discharge the difficultly adsorbed component, and the first inner cavity 102 and the second inner cavity 202 are prepared for the next refrigerant adsorption and separation, thereby being beneficial to improving the working efficiency of the first separation tank 1 and the second separation tank 2.

The high-temperature components which are discharged from the first inner cavity 102 and the second inner cavity 202 and difficult to adsorb directly flow through the first heat exchanger 401 to heat the refrigerant flowing into the first compressor 501, so that heat loss of the components difficult to adsorb in the flowing process is avoided, and the heat utilization rate of the components difficult to adsorb is improved.

Preferably, as shown in fig. 1, the refrigerant recovery system is further provided with a second heat exchanger 402, and the second heat exchanger 402 includes a third channel 4021 and a fourth channel 4022;

an eighth control valve 608 is disposed on the pipeline between the outlet of the first inner cavity 102 and the inlet of the third channel 4021, and a ninth control valve 609 is disposed on the pipeline between the outlet of the second inner cavity 202 and the inlet of the third channel 4021;

the fourth channel 4022 is communicated with the second channel 4012 through a refrigerant circulation pipeline 7, a second compressor 502 is arranged on the refrigerant circulation pipeline 7, an outlet of the second compressor 502 is communicated with an inlet of the second channel 4012, and an inlet of the second compressor 502 is communicated with an outlet of the fourth channel 4022.

Second embodiment of heating gas before entering the first compressor 501:

at this time, the outlet valve group includes an eighth control valve 608 and a ninth control valve 609. When the first internal cavity 102 discharges the difficultly adsorbed component, the eighth control valve 608 is opened, and the ninth control valve 609 is closed; when the second lumen 202 discharges the difficultly adsorbed component, the eighth control valve 608 is closed, and the ninth control valve 609 is opened; compared with the first embodiment, in the second embodiment, the high-temperature difficult-to-adsorb components discharged from the first inner cavity 102 and the second inner cavity 202 do not directly flow through the first heat exchanger 401, but flow through the second heat exchanger 402, the refrigerant circulation pipeline 7 is arranged between the second heat exchanger 402 and the first heat exchanger 401, the high-temperature difficult-to-adsorb components heat the refrigerant in the refrigerant circulation pipeline 7, the heated refrigerant is pressurized and warmed by the second compressor 502 arranged on the circulation pipeline, and the refrigerant before the high-temperature refrigerant pressurized and warmed by the second compressor 502 flows into the first compressor 501 flows through the first heat exchanger 401 to be heated, so that the temperature of the refrigerant before entering the first compressor 501 can be effectively increased; the temperature of the refrigerant heated by the first heat exchanger 401 is reduced, the refrigerant with the reduced temperature absorbs heat from the difficult-to-adsorb component through the second heat exchanger 402 again to raise the temperature, and the refrigerant with the heat absorbed from the difficult-to-adsorb component passes through the second compressor 502 to raise the temperature more, thereby improving the compression efficiency of the first compressor 501. The refrigerant is heated through the components difficult to adsorb, the temperature of the refrigerant is increased, the compression efficiency of the second compressor 502 is further improved, the temperature of the refrigerant discharged by the second compressor 502 is further improved, and the refrigerant discharged by the second compressor 502 heats the refrigerant before the first compressor 501 through the first heat exchanger 401, so that the circulation is realized. The temperature of the refrigerant before the first compressor 501 in the second embodiment is higher than that in the first embodiment.

The second heat exchanger 402 can exchange heat by using the refrigerant in the circulation pipeline 7, which is beneficial to more accurately regulating and controlling the temperature. In this way, the compressor is fully utilized to perform work, and on the one hand, the temperature of the refrigerant in the first passage 4011 can be adjusted to be increased. On the other hand, the increased pressure of the refrigerant exiting the first compressor 501 is beneficial in reducing the energy required to pressurize the system adsorption process.

Preferably, an expansion valve 701 is provided in the refrigerant circulation line 7 between the outlet of the second passage 4012 and the inlet of the fourth passage 4022.

The temperature of the refrigerant after the refrigerant is heated by the first heat exchanger 401 is reduced, and the temperature of the reduced refrigerant is further reduced by the expansion valve 701, and at this time, the temperature of the refrigerant is low, even lower than zero degrees.

The temperature difference between the refrigerant passing through the expansion valve 701 and the difficult-to-adsorb component is larger, the refrigerant absorbs more heat from the difficult-to-adsorb component, and the difficult-to-adsorb component is condensed by the part of the difficult-to-adsorb component after heat exchange with the refrigerant at the moment, that is, the refrigerant passing through the expansion valve 701 has a condensation effect on the difficult-to-adsorb component, and the condensed difficult-to-adsorb component is convenient to recover and store. That is, by providing the refrigerant recovery line, the second compressor 502 and the expansion valve 701, not only heat of the components difficult to adsorb is recovered to improve compression efficiency of the first compressor 501, but also pressure and temperature of the gas discharged from the first compressor 501 are improved; in addition, the refrigerant condenses the components difficult to adsorb, and improves the recovery efficiency of the components difficult to adsorb.

Preferably, a seventh control valve 607 is provided on the conduit between the outlet of the first chamber 102 and the outlet of the second chamber 202.

The control valve block further comprises a seventh control valve 607. An embodiment one includes: a seventh control valve 607, a fifth control valve 605 and a sixth control valve 606; the second embodiment comprises: seventh control valve 607, eighth control valve 608 and ninth control valve 609.

When one of the first cavity 102 or the second cavity 202 is exhausted, the other is completely desorbed in vacuum; at this time, the pressure difference between the two inner cavities is large, and the next step of the inner cavity for completing vacuum desorption is to flush refrigerant to perform adsorption work of easily adsorbed components, and the low pressure is not favorable for adsorption; when one of the first cavity 102 or the second cavity 202 is discharged and the other is subjected to vacuum desorption, the seventh control valve 607 is opened to balance the pressures of the two cavities, that is, the pressure of the cavity for discharging the components difficult to be adsorbed is conveyed and decompressed to the cavity for performing vacuum desorption, so that the pressure of the cavity for performing vacuum desorption is improved, preparation is made for the subsequent adsorption of the components easy to be adsorbed, and the adsorption efficiency of the components easy to be adsorbed is improved.

The contaminated mixed refrigerant contains water, oil, acid, non-condensable gases and solid particulate impurities. When the refrigerant recovery system is used for recovering mixed refrigerant, a flash tank 901 and an oil separator are sequentially arranged between the mixing tank 3 and the first heat exchanger 401, a pressure reducing valve is arranged between the mixing tank 3 and the flash tank 901, a drying filter 919 is arranged between the flash tank 901 and the oil separator, the bottom of the flash tank 901 is connected with a first impurity storage tank 903 through a first stop valve 905, and the bottom of the oil separator is connected with a second impurity storage tank 904 through a second stop valve 906.

In this way, the mixed refrigerant discharged from the mixing tank 3 enters the flash tank 901 through the pressure reducing valve, is coarsely separated in the flash tank 901, the mixed refrigerant after passing through the pressure reducing valve is quickly vaporized in the flash tank 901, the liquid state is changed into the gas state, the bottom of the flash tank 901 is the impurities such as oil, water and the like, and the separated oil and water are stored in the first impurity tank through the first stop valve 905; the gaseous refrigerant in the flash tank 901 enters a dry filter 919 from a top outlet, and the dry filter 919 re-separates water, acid and small solid particles in the gaseous refrigerant; the separated mixed refrigerant enters an oil separator 902 to remove oil; the removed oil is recovered to the second impurity storage tank 904 via the second shut-off valve 906. The mixed refrigerant discharged from the oil separator flows through the first heat exchanger 401. The dry filter 919 may be a zeolite, activated carbon, silica gel, alumina, or a metal organic framework material.

The second storage device includes a first buffer tank 907, a gas-liquid separator 909, a first condenser 914, and a first recovery vessel 913; before the components which are difficult to adsorb after passing through the first heat exchanger 401 or the second heat exchanger 402 are stored, the components enter the first buffer tank 907, and the pressure and purity of the components which are difficult to adsorb and are separated by the two separation tanks can be balanced by the first buffer tank 907.

The components difficult to adsorb flow out from the first buffer tank 907 smoothly and then enter the first condenser 914 to be condensed into liquid; since the mixed refrigerant contains non-condensable gas, the refrigerant flowing out of the first condenser 914 enters the gas-liquid separator 909, the solenoid valve 910 is provided at the top of the gas-liquid separator 909, the non-condensable gas is discharged from the gas-liquid separator 909 through the solenoid valve 910, and the mixed refrigerant is discharged from the gas-liquid separator 909 and enters the first recovery container 913 through the first check valve 911.

The first storage device includes a second condenser 915 and a second recovery vessel 918; the gaseous easily adsorbed refrigerant discharged through the vacuum pump 8 is condensed into a liquid by the second condenser 915 and then flows into the second recovery container 918 through the second check valve 912.

To increase the condensation efficiency of the first condenser 914 and the second condenser 915, a first fan 916 is provided to accelerate the heat exchange of the first condenser 914; a second fan 917 is provided to accelerate heat exchange of the second condenser 915.

step one: controlling the second control valve 602, the fourth control valve 604 and the eleventh control valve 611 to be opened, controlling the outlet valve group to be closed, and controlling the vacuum pump 8 to be started;

step two: controlling the outlet valve group to be in a first mode, closing other control valves, and controlling the vacuum pump 8 to stop; when the outlet valve set is in the first mode, the difficultly adsorbed component within the first interior cavity 102 is discharged from the first interior cavity 102; controlling the second step to keep a second preset time period, and then executing the next step;

step three: controlling the outlet valve group to be in a second mode, closing other control valves, and controlling the vacuum pump 8 to stop; when the outlet valve set is in the first mode, the first interior chamber 102 and the second interior chamber 202 are in communication;

step four: controlling the first control valve 601, the third control valve 603 and the tenth control valve 610 to be opened, controlling the outlet valve group to be closed and controlling the vacuum pump 8 to be opened;

step five: controlling the outlet valve group to be in a third mode, and closing other control valves; when the outlet valve set is in the third mode, the less adsorbable component within the second lumen 202 is discharged from the second lumen 202;

and so on.

Step one: the second control valve 602, the fourth control valve 604 and the eleventh control valve 611 are opened, the outlet valve group is closed, and the vacuum pump 8 is started for a first preset period of time;

in a first preset period of time, the mixed refrigerant enters the second interlayer 201 through the second control valve 602 to heat the second inner cavity 202, so that the temperature in the second inner cavity 202 is raised, the vacuum pump 8 is started to vacuumize the second inner cavity 202, the pressure in the second inner cavity 202 is reduced, and the easily-adsorbed components adsorbed by the adsorbent in the second inner cavity 202 are desorbed and flow out through the eleventh control valve 611 and the vacuum pump 8 through the driving of the vacuum pump 8 to finish desorption; at the same time, the refrigerant in the second interlayer 201 continuously flows into the first inner cavity 102 through the fourth control valve 604, the easily adsorbable component contained in the refrigerant is adsorbed by the adsorbent in the first inner cavity 102 and releases heat to the difficultly adsorbable component, and the difficultly adsorbable component is enriched in the first inner cavity 102.

Step two: the outlet valve group is in a first mode, other control valves are closed, the vacuum pump 8 is stopped, and a second preset time period is kept;

in the second preset time period, the outlet valve group is in the first mode, the difficultly adsorbed component in the first inner cavity 102 flows out through the outlet valve group, and the concentration of the difficultly adsorbed component in the first inner cavity 102 is reduced.

Step three: the outlet valve group is in a second mode, other control valves are closed, the vacuum pump 8 is stopped, and a third preset time period is kept;

during a third preset period, the outlet valve set is in a second mode, in which the first inner cavity 102 and the second inner cavity 202 are communicated, and because in the first step, the suction pressure of the second inner cavity 202 through the vacuum pump 8 is lower, when the first inner cavity 102 and the second inner cavity 202 are communicated, a part of the components difficult to adsorb in the first inner cavity 102 flows to the second inner cavity 202, so that the pressure in the second inner cavity 202 is increased, and the second inner cavity 202 is ready for adsorbing the components easy to adsorb in the next adsorbent. It is explained herein that the higher the pressure, the more advantageous the adsorption, and when a certain amount of refrigerant is charged into the inner chamber, the higher the original pressure of the inner chamber, the higher the pressure after the refrigerant is charged, thereby improving the adsorption effect of the adsorbent on the easily adsorbed components.

Step four: the first control valve 601, the third control valve 603 and the tenth control valve 610 are opened, the outlet valve group is closed, the vacuum pump 8 is opened, and a fourth preset time period is maintained;

in a fourth preset period, the mixed refrigerant enters the first interlayer 101 through the first control valve 601 to heat the first inner cavity 102, so that the temperature in the first inner cavity 102 is raised, the vacuum pump 8 is started to vacuumize the first inner cavity 102, the pressure in the first inner cavity 102 is reduced, and the easily-adsorbed components adsorbed by the adsorbent in the first inner cavity 102 are desorbed and flow out through the tenth control valve 610 and the vacuum pump 8 through the driving of the vacuum pump 8 to finish desorption; at the same time, the refrigerant in the first interlayer 101 continuously flows into the second inner cavity 202 through the third control valve 603, the easily adsorbable component contained in the refrigerant is adsorbed by the adsorbent in the second inner cavity 202 and releases heat to the difficultly adsorbable component, and the difficultly adsorbable component is enriched in the second inner cavity 202.

Step five: the outlet valve group is in a third mode, other control valves are closed, and a fifth preset duration is kept;

in the fifth preset time period, the outlet valve set is in the third mode, the difficultly adsorbed component in the second inner cavity 202 flows out through the outlet valve set, and the concentration of the difficultly adsorbed component in the second inner cavity 202 is reduced.

Step six: and the outlet valve group is in a second mode, and other control valves are closed for a sixth preset duration.

During the sixth preset period, the outlet valve set is in the second mode, in which the first inner cavity 102 and the second inner cavity 202 are communicated, and because in the fourth step, the suction pressure of the first inner cavity 102 through the vacuum pump 8 is lower, when the second inner cavity 202 and the first inner cavity 102 are communicated, a part of the components difficult to be adsorbed in the second inner cavity 202 flows to the first inner cavity 102, so that the pressure in the first inner cavity 102 is increased, and the first inner cavity 102 is ready for adsorbing the components easy to be adsorbed by the adsorbent next time.

Preferably:

when the refrigerant recovery system is provided with a second compressor 502, when the refrigerant recovery system is in the step one, the second compressor 502 is also controlled to be started for the first preset period of time; the second compressor 502 is also controlled to start and last for the fourth preset time period when the refrigerant recovery system is in the fourth step.

In the first step, the refrigerant continuously flows through the first heat exchanger 401, and at this time, the second compressor 502 continuously heats the refrigerant flowing through the first heat exchanger 401, and the duration is consistent with the duration of the refrigerant flowing through the first heat exchanger 401 in the first step; similarly, in step four, the refrigerant continuously flows through the first heat exchanger 401, and at this time, the second compressor 502 is operated to continuously heat the refrigerant flowing through the first heat exchanger 401, and the duration is consistent with the duration of the refrigerant flowing through the first heat exchanger 401 in step four; not only can the refrigerant flowing through the first heat exchanger 401 be heated in this way; the condition that the second compressor 502 works to continuously heat the refrigerant which does not flow in the first heat exchanger 401 is avoided, so that the temperature difference between the first passage 4011 and the second passage 4012 is reduced, and the heating efficiency is reduced; thereby improving the heating efficiency of the refrigerant.

The refrigerant recovery system is in operation:

the second control valve 602, the fourth control valve 604, and the eleventh control valve 611 are opened, and the other control valves are closed; at this time, the temperature and pressure of the refrigerant discharged from the compressor are high, the refrigerant enters the second interlayer 201 to heat the adsorbent in the second inner cavity 202, which has completed adsorption of the easily adsorbed component, and the vacuum pump 8 starts to vacuumize the second inner cavity 202, so that the easily adsorbed component in the second inner cavity 202 is quickly desorbed from the adsorbent in a high-temperature low-pressure environment (the process can be called as high-temperature vacuum desorption), and the desorbed easily adsorbed component is discharged from the outlet of the vacuum pump 8 and collected after being driven by the vacuum pump 8; meanwhile, the temperature of the refrigerant in the second interlayer 201 after absorbing heat by the second inner cavity 202 is reduced, but the pressure is still high, and the refrigerant with reduced temperature is discharged from the second interlayer 201 and enters the first inner cavity 102 through the fourth control valve 604; in the first interior chamber 102, the refrigerant is contacted with an adsorbent, wherein the adsorbable component of the refrigerant is adsorbed by the adsorbent; because the pressure and temperature of the refrigerant entering the first cavity 102 are higher, the adsorption efficiency of the easily adsorbed components in the first cavity 102 is higher.

After the easily adsorbed component in the first inner cavity 102 is adsorbed, the difficultly adsorbed component needs to be discharged; the fifth control valve 605 is opened, and the other control valves are closed; since the adsorption process is exothermic, the hardly adsorbable component stores heat released during adsorption of the easily adsorbable component, and the hardly adsorbable component increases in temperature and is discharged through the fifth control valve 605.

After the components difficult to adsorb in the first inner cavity 102 are discharged, on one hand, the components easy to adsorb in the first inner cavity 102 need to be discharged in a desorption mode, and on the other hand, the adsorption pressure of the second inner cavity 202 through the vacuum pump 8 is lower, and the pressure of the second inner cavity 202 needs to be raised to prepare for the next adsorption operation of the second inner cavity 202; the seventh control valve 607 is opened, and the other control valves are closed; the residual components difficult to adsorb in the first inner cavity 102 flow to the second inner cavity 202 through the seventh control valve 607, so that the pressure of the second inner cavity 202 is increased, and meanwhile, the concentration of the components difficult to adsorb in the first inner cavity 102 is reduced, thereby being beneficial to the recovery purity of the components easy to adsorb in the first inner cavity 102.

After the first inner cavity 102 and the second inner cavity 202 are subjected to pressure equalizing, the easily-adsorbed components in the first inner cavity 102 are subjected to desorption, and the second inner cavity 202 is subjected to adsorption of the easily-adsorbed components; at this time, the first control valve 601, the third control valve 603, and the tenth control valve 610 are opened, and the other control valves are closed; the temperature and the pressure of the refrigerant discharged by the compressor are high, the refrigerant enters the first interlayer 101 to heat the adsorbent which is adsorbed by the easily adsorbed component in the first inner cavity 102, the vacuum pump 8 starts vacuumizing the first inner cavity 102, the easily adsorbed component in the first inner cavity 102 is quickly desorbed from the adsorbent under the environment of high temperature and low pressure, and the desorbed easily adsorbed component is discharged from the outlet of the vacuum pump 8 and collected after being driven by the vacuum pump 8; meanwhile, the temperature of the refrigerant in the first interlayer 101 after absorbing heat by the first inner cavity 102 is reduced, but the pressure is still high, and the refrigerant after reducing the temperature is discharged from the first interlayer 101 and enters the second inner cavity 202 through the third control valve 603; in the second internal cavity 202, the refrigerant is contacted with the adsorbent, wherein the adsorbable component of the refrigerant is adsorbed by the adsorbent; because the pressure and temperature of the refrigerant entering the second cavity 202 are higher, the adsorption efficiency of the easily adsorbed components in the second cavity 202 is higher.

After the easily adsorbed component in the second cavity 202 is adsorbed, the difficultly adsorbed component needs to be discharged; the sixth control valve 606 is opened and the other control valves are closed; since the adsorption process is exothermic, the hardly adsorbable component stores heat released during adsorption of the easily adsorbable component, and the hardly adsorbable component increases in temperature and is discharged through the sixth control valve 606.

After the components difficult to adsorb in the second inner cavity 202 are discharged, on one hand, the components easy to adsorb in the second inner cavity 202 need to be discharged in a desorption mode, on the other hand, the adsorption pressure of the first inner cavity 102 through the vacuum pump 8 is lower, and the pressure of the first inner cavity 102 needs to be raised to prepare for the next adsorption operation of the first inner cavity 102; the seventh control valve 607 is opened, and the other control valves are closed; the residual components difficult to adsorb in the second inner cavity 202 flow to the first inner cavity 102 through the seventh control valve 607, so that the pressure of the first inner cavity 102 is increased, and meanwhile, the concentration of the components difficult to adsorb in the second inner cavity 202 is reduced, thereby being beneficial to the recovery purity of the components easy to adsorb in the second inner cavity 202.

The first separation tank 1 and the second separation tank 2 are used for separating the refrigerant to be separated alternately according to the steps, so that the efficiency of recovering, purifying and separating the azeotropic or near-azeotropic refrigerant is effectively improved.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention. The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. A refrigerant recovery system for separating readily adsorbable components from difficultly adsorbable components in a refrigerant, comprising:

a mixing tank (3) for storing a refrigerant to be recovered;

a first heat exchanger (401) having a first path (4011) and a second path (4012) coupled to each other; the inlet of the first passage (4011) is communicated with the outlet of the mixing tank (3);

a first compressor (501) having an inlet in communication with an outlet of the first passage (4011);

-a separation device, the inlet of which communicates with the outlet of the first compressor (501); the separation device comprises a first outlet from which the easily adsorbable component is discharged and a second outlet from which the less easily adsorbable component is discharged, a second passageway (4012) from which a portion of the heat of the less easily adsorbable component discharged from the second outlet is used to warm the refrigerant flowing through the first passageway (4011);

2. Refrigerant recovery system according to claim 1, characterized in that the separation device comprises a first separation tank (1) and a second separation tank (2);

the first separating tank (1) and the second separating tank (2) are of double-layer shell structures;

the cavity between the double-layer shells of the first separation tank (1) is a first interlayer (101), and the inner cavity of the first separation tank (1) is a first inner cavity (102); the cavity between the double-layer shells of the second separation tank (2) is a second interlayer (201), and the inner cavity of the second separation tank (2) is a second inner cavity (202);

the outlet of the first compressor (501) is selectively communicated with the first interlayer (101) and the second interlayer (201), and adsorbents are arranged in the first inner cavity (102) and the second inner cavity (202).

3. Refrigerant recovery system according to claim 2, characterized in that a first control valve (601) is arranged on the pipe connected between the outlet of the first compressor (501) and the inlet of the first interlayer (101), a second control valve (602) is arranged on the pipe connected between the outlet of the first compressor (501) and the inlet of the second interlayer (201), a third control valve (603) is arranged on the pipe connected between the outlet of the first interlayer (101) and the inlet of the second inner chamber (202), and a fourth control valve (604) is arranged on the pipe connected between the outlet of the second interlayer (201) and the inlet of the first inner chamber (102).

4. A refrigerant recovery system as claimed in claim 3, wherein the first storage means comprises a vacuum pump (8), a tenth control valve (610) being provided on a pipe between an air inlet of the vacuum pump (8) and an air inlet of the first inner chamber (102), an eleventh control valve (611) being provided on a pipe between an air inlet of the vacuum pump (8) and an air inlet of the second inner chamber (202);

the separation device comprises an outlet valve group, and the components difficult to adsorb, which are discharged from the first separation tank (1) and the second separation tank (2), are discharged to the second storage device after passing through the outlet valve group.

5. The refrigerant recovery system according to claim 4, wherein a fifth control valve (605) is provided on a pipe between an outlet of the first inner chamber (102) and an inlet of the second passage (4012), and a sixth control valve (606) is provided on a pipe between an outlet of the second inner chamber (202) and an inlet of the second passage (4012).

6. The refrigerant recovery system according to claim 4, further provided with a second heat exchanger (402), the second heat exchanger (402) comprising a third pass (4021) and a fourth pass (4022);

An eighth control valve (608) is arranged on a pipeline between the outlet of the first inner cavity (102) and the inlet of the third passage (4021), and a ninth control valve (609) is arranged on a pipeline between the outlet of the second inner cavity (202) and the inlet of the third passage (4021);

the fourth passage (4022) is communicated with the second passage (4012) through a refrigerant circulation pipeline (7), a second compressor (502) is arranged on the refrigerant circulation pipeline (7), an outlet of the second compressor (502) is communicated with an inlet of the second passage (4012), and an inlet of the second compressor (502) is communicated with an outlet of the fourth passage (4022).

7. The refrigerant recovery system according to claim 6, wherein an expansion valve (701) is provided on the refrigerant circulation line (7) between an outlet of the second passage (4012) and an inlet of the fourth passage (4022).

8. A refrigerant recovery system according to claim 5 or 6, wherein a seventh control valve (607) is provided in the conduit between the outlet of the first inner chamber (102) and the outlet of the second inner chamber (202).

9. A control method for the refrigerant recovery system according to claim 5 or 6, characterized by comprising the steps of:

Step one: controlling the second control valve (602), the fourth control valve (604) and the eleventh control valve (611) to be opened, controlling the outlet valve group to be closed, and controlling the vacuum pump (8) to be started;

step two: controlling the outlet valve group to be in a first mode, closing other control valves, and controlling the vacuum pump (8) to stop; -when the outlet valve set is in the first mode, the hardly adsorbable component within the first inner chamber (102) is discharged from the first inner chamber (102); controlling the second step to keep a second preset time period, and then executing the next step;

step three: controlling the outlet valve group to be in a second mode, closing other control valves, and controlling the vacuum pump (8) to stop; -said first inner chamber (102) and said second inner chamber (202) are in communication when said outlet valve block is in said first mode;

step four: controlling the first control valve (601), the third control valve (603) and the tenth control valve (610) to be opened, controlling the outlet valve group to be closed and controlling the vacuum pump (8) to be opened;

step five: controlling the outlet valve group to be in a third mode, and closing other control valves; -when the outlet valve set is in the third mode, the hardly adsorbable component within the second inner chamber (202) is discharged from the second inner chamber (202);

and so on.

10. A control method for the refrigerant recovery system according to claim 9, characterized by:

when the refrigerant recovery system is provided with a second compressor (502), when the refrigerant recovery system is in the step one, further controlling the second compressor (502) to start and last for the first preset period of time; the second compressor (502) is also controlled to start and last for the fourth preset time period when the refrigerant recovery system is in the fourth step.