CN114353401B

CN114353401B - Refrigerant recovery control method and device and refrigerant recovery system

Info

Publication number: CN114353401B
Application number: CN202111570435.6A
Authority: CN
Inventors: 杨巨沁; 张新明; 王成; 周涯宸
Original assignee: Aux Air Conditioning Co Ltd; Ningbo Aux Electric Co Ltd
Current assignee: Aux Air Conditioning Co Ltd; Ningbo Aux Electric Co Ltd
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2023-09-15
Anticipated expiration: 2041-12-21
Also published as: CN114353401A

Abstract

The invention provides a refrigerant recovery control method and device and a refrigerant recovery system, and relates to the technical field of refrigerant recovery. The refrigerant recovery control method can control the compressor to adjust the running frequency according to the real-time exhaust pressure value of the compressor and the real-time temperature value of the condenser, so that the real-time exhaust pressure value of the compressor approaches to a preset pressure value, the refrigerant recovery efficiency is improved to the best, and the excessive consumption of energy sources can be prevented. The refrigerant recovery control device and the refrigerant recovery system provided by the invention can execute the refrigerant recovery control method. The refrigerant recovery control method and device and the refrigerant recovery system can solve the technical problem that in the prior art, excessive energy consumption is caused to improve the recovery efficiency of the refrigerant, so that energy conservation is not facilitated.

Description

Refrigerant recovery control method and device and refrigerant recovery system

Technical Field

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

Background

Besides the insufficient environmental awareness of operators, the refrigerant recovery device has an important reason that various defects such as low recovery speed and efficiency exist in the practical application process of many refrigerant recovery devices at present, but the recovery device with relatively high recovery speed has the problems of relatively large volume, inconvenient transportation and carrying and the like, but some of the recovery devices with small volume and relatively slow recovery speed of portable devices.

However, in the prior art, in order to improve the recovery efficiency of the refrigerant, an operator is generally required to control the compressor by virtue of own experience, so as to achieve the purpose of improving the recovery efficiency of the refrigerant; however, such a control method is generally liable to cause excessive consumption of energy, which is disadvantageous in energy saving.

Disclosure of Invention

The invention solves the technical problems that in the prior art, excessive energy consumption is caused to improve the recovery efficiency of a refrigerant, and energy conservation is not facilitated.

In order to solve the problems, the invention provides a refrigerant recovery control method which is applied to a refrigerant recovery system, wherein the refrigerant recovery system comprises a recovery pipeline, one end of the recovery pipeline is connected to a system to be recovered, and the other end of the recovery pipeline is connected to a recovery container; the recovery pipeline is provided with a compressor and a condenser, and the compressor is used for extracting a gaseous refrigerant in the system to be recovered during operation and guiding the refrigerant to the condenser so as to guide the refrigerant into the recovery container;

the refrigerant recovery control method comprises the following steps:

receiving a real-time discharge pressure value, wherein the real-time discharge pressure value represents the real-time pressure of a refrigerant in an exhaust pipe of the compressor;

Receiving a real-time temperature value, wherein the real-time temperature value represents the real-time temperature of the middle part of the condenser;

and controlling the compressor to determine the operating frequency according to the real-time exhaust pressure value, the preset pressure value, the real-time temperature value and the preset temperature value so as to enable the real-time exhaust pressure value to approach the preset pressure value.

Compared with the prior art, the refrigerant recovery control method provided by the invention has the beneficial effects that:

in the process of refrigerant recovery, the operation frequency of the compressor influences the temperature of the refrigerant, so that the temperature of the middle part of the condenser is influenced, and the recovery speed of the refrigerant is related to the temperature of the middle part of the condenser based on the temperature. In addition, under the condition that the temperature of the middle part of the condenser reaches a preset temperature value, the recovery speed of the refrigerant reaches the best; if the operation frequency of the compressor is continuously increased to increase the temperature of the middle part of the condenser, the recovery speed of the refrigerant is not increased, but excessive energy consumption is caused, and the energy saving is not facilitated. In addition, in the case that the middle of the condenser reaches a preset temperature value, the discharge pressure of the compressor reaches a preset pressure value. The control accuracy of controlling the operation frequency of the compressor by only the temperature of the middle part of the condenser is low, so that the operation frequency of the compressor is controlled by the real-time temperature value of the middle part of the condenser and the real-time exhaust pressure value of the compressor, the recovery speed of the refrigerant can be adjusted to the optimal speed, and the excessive consumption of energy sources is prevented. That is, the refrigerant recovery control method provided by the invention can solve the technical problems that in the prior art, in order to improve the recovery efficiency of the refrigerant, the energy consumption is excessive, and the energy saving is not facilitated.

In order to prevent the detection error and the detection hysteresis from affecting the control accuracy of the compressor, optionally, the step of controlling the compressor to determine the operating frequency according to the real-time discharge pressure value, the preset pressure value, the real-time temperature value and the preset temperature value includes:

calculating a first pressure threshold and a second pressure threshold according to the preset pressure value, wherein the first pressure threshold is larger than the second pressure threshold;

calculating a first temperature threshold and a second temperature threshold according to a preset temperature value, wherein the first temperature threshold is larger than the second temperature threshold;

and controlling the compressor to determine the operating frequency according to the real-time exhaust pressure value, the real-time temperature value, the first pressure threshold value, the second pressure threshold value, the first temperature threshold value and the second temperature threshold value.

Optionally, the step of controlling the compressor to adjust the operating frequency according to the real-time discharge pressure value, the real-time temperature value, the first pressure threshold, the second pressure threshold, the first temperature threshold and the second temperature threshold comprises:

comparing at least one of the first pressure threshold and the second pressure threshold with the real-time exhaust pressure value to determine a magnitude relationship between the first pressure threshold, the second pressure threshold, and the real-time exhaust pressure value;

Comparing at least one of the first temperature threshold and the second temperature threshold with the real-time temperature value to judge the magnitude relation among the first temperature threshold, the second temperature threshold and the real-time temperature value;

controlling the compressor to adjust the operating frequency or controlling the compressor to maintain the current operating frequency according to the magnitude relation among the first pressure threshold value, the second pressure threshold value and the real-time exhaust pressure value and the magnitude relation among the first temperature threshold value, the second temperature threshold value and the real-time temperature value;

after controlling the compressor to adjust the operating frequency, controlling the compressor to operate for a first preset time, returning to the step of re-performing the comparison of at least one of the first pressure threshold and the second pressure threshold with the real-time discharge pressure value, and the step of comparing at least one of the first temperature threshold and the second temperature threshold with the real-time temperature value.

Through the adjustment of many times, can be with the operating frequency adjustment of compressor to can realize that refrigerant recovery speed reaches the best, and the condition of not excessively consuming the energy.

Optionally, the step of controlling the compressor to adjust the operating frequency or controlling the compressor to maintain the current operating frequency according to the magnitude relation between the first pressure threshold, the second pressure threshold and the real-time exhaust pressure value and the magnitude relation between the first temperature threshold, the second temperature threshold and the real-time temperature value comprises:

if the real-time exhaust pressure value is greater than the first pressure threshold value or the real-time temperature value is greater than the first temperature threshold value, controlling the compressor to reduce the operating frequency until the real-time exhaust pressure value is less than or equal to the preset pressure value and the real-time temperature value is less than or equal to the preset temperature value;

if the real-time exhaust pressure value is smaller than the second pressure threshold value or the real-time temperature value is smaller than the second temperature threshold value, controlling the compressor to increase the operating frequency until the real-time exhaust pressure value is larger than or equal to the preset pressure value and the real-time temperature value is larger than or equal to the preset temperature value;

and if the real-time exhaust pressure value is smaller than or equal to the first pressure threshold value and larger than or equal to the second pressure threshold value, controlling the compressor to maintain the current running frequency to run until the recovery of the refrigerant is completed.

Optionally, the step of controlling the compressor to reduce the operating frequency includes:

controlling the operation frequency of the compressor to reduce a first frequency value every second preset time;

the step of controlling the compressor to raise the operating frequency includes:

controlling the operation frequency of the compressor to rise by a second frequency value every third preset time;

wherein the second preset time is less than the third preset time.

In order to prevent the operation frequency of the compressor from repeatedly fluctuating, optionally, the refrigerant recovery control method further includes:

each time the compressor is continuously controlled to finish increasing the operating frequency once and finish reducing the operating frequency once, counting once;

if the count reaches the preset times, after the operation frequency of the compressor is controlled to be increased, the operation of the compressor is controlled to be carried out according to the increased operation frequency until the recovery of the refrigerant is completed.

Optionally, the step of calculating the first pressure threshold and the second pressure threshold according to the preset pressure value includes:

adding a first preset value to the preset pressure value to obtain a first pressure threshold;

subtracting a second preset value from the preset pressure value to obtain a second pressure threshold;

the step of calculating the first temperature threshold and the second temperature threshold according to the preset temperature value comprises the following steps:

Adding a third preset value to the preset temperature value to obtain the first temperature threshold;

and subtracting a fourth preset value from the preset temperature value to obtain the second temperature threshold.

Optionally, before receiving the real-time exhaust pressure value, the refrigerant recovery control method further includes:

judging whether the running time of the compressor reaches a fourth preset time or not;

if yes, executing the step of receiving the real-time exhaust pressure value;

if not, controlling the compressor to be started, controlling the operation frequency of the compressor to increase a third frequency value every fifth preset time until the operation frequency of the compressor is greater than or equal to the preset pressure value, and executing the step of receiving the real-time exhaust pressure value.

The refrigerant recovery control device is applied to a refrigerant recovery system, the refrigerant recovery system comprises a recovery pipeline, one end of the recovery pipeline is connected to a system to be recovered, and the other end of the recovery pipeline is connected to a recovery container; the recovery pipeline is provided with a compressor and a condenser, and the compressor is used for extracting a gaseous refrigerant in the system to be recovered during operation and guiding the refrigerant to the condenser so as to guide the refrigerant into the recovery container;

The refrigerant recovery control device includes:

the first receiving module is used for receiving a real-time exhaust pressure value, and the real-time exhaust pressure value represents the real-time pressure of a refrigerant in an exhaust pipe of the compressor;

the second receiving module is used for receiving a real-time temperature value, and the real-time temperature value represents the temperature of the middle part of the condenser;

and the control module is used for controlling the compressor to determine the operating frequency according to the real-time exhaust pressure value, the preset pressure value, the real-time temperature value and the preset temperature value so as to enable the real-time exhaust pressure value to approach the preset pressure value.

A refrigerant recovery system comprises a recovery pipeline, wherein one end of the recovery pipeline is connected with a system to be recovered, and the other end of the recovery pipeline is connected with a recovery container; the recovery pipeline is provided with a compressor and a condenser, and the compressor is used for extracting a gaseous refrigerant in the system to be recovered during operation and guiding the refrigerant to the condenser so as to guide the refrigerant into the recovery container; the refrigerant recovery system further comprises a pressure detection device, a temperature detection device and a controller; the pressure detection device is arranged on an exhaust pipe of the compressor so as to detect a real-time exhaust pressure value of the exhaust pipe; the temperature detection device is arranged in the middle of the condenser to detect the real-time temperature value of the condenser; the pressure detection device and the temperature detection device are electrically connected with a controller, and the controller is used for receiving the real-time exhaust pressure value and the real-time temperature value and executing the refrigerant recovery control method.

The refrigerant recovery control device and the refrigerant recovery system provided by the application can execute the refrigerant recovery control method, and the beneficial effects of the refrigerant recovery control device and the refrigerant recovery system relative to the prior art are the same as those of the refrigerant recovery control method provided by the application relative to the prior art, and are not repeated here.

Drawings

Fig. 1 is a schematic structural diagram of a refrigerant recovery system according to an embodiment of the present application;

FIG. 2 is a graph showing a relationship between discharge pressure of a compressor and refrigerant recovery speed;

FIG. 3 is a graph showing a relationship between a temperature of a middle portion of the condenser and a refrigerant recovery rate;

FIG. 4 is a flow chart of a refrigerant recovery control method according to an embodiment of the present application;

FIG. 5 is a flow chart of another part of the refrigerant recovery control method according to the embodiment of the application;

fig. 6 is a flowchart of step S30 in the refrigerant recovery control method according to the embodiment of the present application;

FIG. 7 is a flowchart of step S33 in the refrigerant recovery control method according to the embodiment of the present application;

fig. 8 is a flowchart of step S333 in the refrigerant recovery control method according to the embodiment of the present application;

FIG. 9 is a flow chart of a further part of the refrigerant recovery control method according to the embodiment of the application;

Fig. 10 is a schematic functional block diagram of a refrigerant recovery control device according to an embodiment of the present application.

Reference numerals illustrate:

10-a refrigerant recovery system; 11-a system to be recycled; 100-recovering pipeline; 110-a compressor; 120-laval nozzle; 130-a condenser; 140-a first solenoid valve; 200-a liquid refrigerant recovery branch; 210 a second solenoid valve; 300-mixing branch; 400-recovery vessel; 500-supercharging device; 20-refrigerant recovery control device; 21-a first receiving module; 22-a second receiving module; 23-control module.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

In the process of recycling part of the refrigeration system, the refrigerant in the refrigeration system needs to be recycled. The refrigerant recovery system 10 can be used for recovering the refrigerant in the refrigeration system. The refrigeration system includes a system to be recovered 11 for containing a refrigerant, where the system to be recovered 11 may be a compressor 110 of the refrigeration system, a refrigerant circulation circuit, or other containers for containing a refrigerant. The refrigerant recovery system 10 is connected to the to-be-recovered system 11 to guide out the refrigerant in the to-be-recovered system 11 to the recovery container 400 in the refrigerant recovery system 10, thereby completing the recovery of the refrigerant.

Referring to fig. 1, a refrigerant recovery system 10 includes a recovery pipeline 100, a recovery container 400 and a liquid refrigerant recovery branch 200, wherein one end of the recovery pipeline 100 and one end of the liquid refrigerant recovery branch 200 are connected to the recovery container 400; the other end of the recovery pipeline 100 is used for being connected to the system to be recovered 11 so as to be used for recovering the gaseous refrigerant in the system to be recovered 11; the other end of the liquid refrigerant recovery branch 200 is also used for accessing the system to be recovered 11, so as to recover the liquid refrigerant in the system to be recovered 11. Wherein, the recovery pipeline 100 is provided with a compressor 110, a Laval nozzle 120, a condenser 130 and a first electromagnetic valve 140, and in the process of recovering the gaseous refrigerant by the recovery pipeline 100, the gaseous refrigerant sequentially passes through the compressor 110, the Laval nozzle 120, the condenser 130 and the first electromagnetic valve 140 and is then led into the recovery container 400. In addition, the liquid refrigerant recovery branch 200 is provided with a second electromagnetic valve for selectively opening or closing the liquid refrigerant recovery branch 200. In the embodiment of the present application, the refrigerant recovery system 10 further includes a mixing branch 300, wherein one end of the mixing branch 300 is connected to the recovery pipeline 100, and the other end is connected to the liquid refrigerant recovery branch 200. It should be noted that, the end of the mixing branch 300 connected to the recovery pipeline 100 is located between the laval nozzle 120 and the condenser 130; one end of the mixing branch 300 connected to the liquid refrigerant recovery branch 200 is located between the second electromagnetic valve and the system to be recovered 11.

In general, the system 11 to be recovered stores liquid refrigerant and gaseous refrigerant, and in the process of refrigerant recovery, the recovery pipeline 100 recovers the gaseous refrigerant through the extraction of the compressor 110; the liquid refrigerant recovery branch 200 can be connected to the low level of the system 11 to be recovered, and the recovery of the liquid refrigerant can be realized through the flowing action of the liquid refrigerant. Naturally, in order to improve the recovery efficiency, the refrigerant is ensured to be recovered quickly and efficiently. The refrigerant recovery system 10 may further include a pressurizing device 500, where the pressurizing device 500 is used for accessing the to-be-recovered system 11 to charge gas into the to-be-recovered system 11, so as to ensure that the gas pressure in the to-be-recovered system 11 is stable or is increased, so that the gaseous refrigerant and the liquid refrigerant in the to-be-recovered system 11 can be conveniently led out of the to-be-recovered system 11, and the purpose of improving the refrigerant recovery efficiency can be achieved.

In the process of recovering the gaseous refrigerant, since the laval nozzle 120 forms a low pressure at the end thereof, the mixing branch 300 is connected to one end of the recovery pipeline 100 to form a low pressure, and at this time, the mixing branch 300 may be turned on and the second electromagnetic valve may be closed, so that the liquid refrigerant is led into the recovery pipeline 100 from the mixing branch 300, so that the liquid refrigerant may be mixed with other refrigerants, thereby recovering the mixed refrigerant.

Of course, in general, the recovery rate of the liquid refrigerant is greater than that of other refrigerants, and in the process of recovering the refrigerant, the volatilization of the liquid refrigerant is accompanied, so that the other refrigerants in the volatilized part are recovered, and in general, the pure gaseous refrigerant is recovered at the end time of the refrigerant recovery process.

Referring to fig. 2 and 3, fig. 2 shows a relationship between the discharge pressure of the compressor 110 and the refrigerant recovery speed; fig. 3 shows a relationship between the temperature of the middle portion of the condenser 130 and the refrigerant recovery rate. As can be seen from fig. 2 and 3, during the recovery of the pure gaseous refrigerant, the operation frequency of the compressor 110 affects the temperature of the refrigerant, and thus the temperature of the middle portion of the condenser 130, and based on this, the recovery rate of the refrigerant is related to the temperature of the middle portion of the condenser 130. And, in case that the temperature of the middle part of the condenser 130 reaches a preset temperature value, the recovery speed of the refrigerant reaches an optimum; if the operation frequency of the compressor 110 is continuously increased to increase the temperature of the middle portion of the condenser 130, the recovery rate of the refrigerant is not increased, but excessive energy consumption is caused, which is not beneficial to energy saving. In addition, in case that the middle portion of the condenser 130 reaches a preset temperature value, the discharge pressure of the compressor 110 reaches a preset pressure value. And the control accuracy of controlling the operation frequency of the compressor 110 by only the temperature of the middle portion of the condenser 130 is low. Therefore, by controlling the operation frequency of the compressor 110 through the real-time temperature value of the middle portion of the condenser 130 and the real-time discharge pressure value of the compressor 110, it is possible to achieve the adjustment of the recovery speed of the refrigerant to an optimal speed while preventing the excessive consumption of energy.

In order to ensure that the recovery can be completed quickly in the recovery process of the gaseous refrigerant and avoid excessive consumption of energy, the refrigerant recovery system 10 in the application is provided. The refrigerant recovery system 10 further includes a pressure detection device, a temperature detection device, and a controller. Wherein, the pressure detection device is arranged at the exhaust pipe of the compressor 110 and is used for detecting the real-time exhaust pressure value of the compressor 110; the temperature detecting means is provided at the middle of the condenser 130 for detecting a real-time temperature value of the middle of the condenser 130. And the pressure detection device and the temperature detection device are electrically connected with the controller and are used for sending the real-time exhaust pressure value and the real-time temperature value obtained by detection to the controller. The controller may then determine an operating frequency of the compressor 110 based on the obtained real-time discharge pressure value and the real-time temperature value, and control the operation of the compressor 110 at the determined operating frequency.

The controller may be an integrated circuit chip having signal processing capabilities. The controller may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a single-chip microcomputer, a micro-control unit (Microcontroller Unit, MCU), a complex programmable logic device (Complex Programmable Logic Device, CPLD), a Field-programmable gate array (Field-Programmable Gate Array, FPGA), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), an embedded ARM, or other chips, and may implement or execute the methods, steps, and logic blocks disclosed in the embodiments of the present application.

In a possible implementation manner, the refrigerant recovery system 10 may further include a memory, where the memory is used to store program instructions that can be executed by the controller, for example, the refrigerant recovery control device 20 provided in the embodiment of the present application, where the refrigerant recovery control device 20 provided in the embodiment of the present application includes at least one of the refrigerant recovery control device and the refrigerant recovery control device may be stored in the memory in a form of software or firmware. The Memory may be a stand-alone external Memory including, but not limited to, random access Memory (Random Access Memory, RAM), read Only Memory (ROM), programmable Read Only Memory (Programmable Read-Only Memory, PROM), erasable Read Only Memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable Read Only Memory (Electric Erasable Programmable Read-Only Memory, EEPROM). The memory may also be provided integrally with the controller, e.g. the memory may be provided integrally with the controller in the same chip.

It should be noted that, when only the gaseous refrigerant exists in the system 11 to be recovered, the refrigerant in the system 11 to be recovered may be recovered by the refrigerant recovery system 10 to form pure gaseous refrigerant recovery; in addition, in the case where the liquid refrigerant and the gaseous refrigerant exist in the system to be recovered 11, but the recovery of the liquid refrigerant is inconvenient at this time, or the liquid refrigerant recovery branch 200 cannot operate normally, the recovery of the gaseous refrigerant in the system to be recovered 11 is performed only through the recovery pipeline 100, which may be regarded as the recovery of the refrigerant forming a pure gas. Under the above circumstances, the above method for adjusting the operation frequency of the compressor 110 according to the real-time exhaust pressure value of the compressor 110 and the real-time temperature of the middle part of the condenser 130 can be adopted, so as to solve the technical problem that the excessive energy consumption is unfavorable for energy saving due to the improvement of the recovery efficiency of the refrigerant in the prior art.

Based on the refrigerant recovery system 10 provided by the application, in order to solve the technical problem that the energy consumption is excessive and is unfavorable for energy saving caused by the improvement of the recovery efficiency of the refrigerant in the prior art, the application also provides a refrigerant recovery control method which can be executed by the refrigerant recovery system 10 provided by the application so as to achieve the aim.

Referring to fig. 4, the refrigerant recovery control method includes:

step S10, receiving a real-time exhaust pressure value.

Step S20, receiving a real-time temperature value.

The real-time exhaust pressure value is detected and obtained by the pressure detection device and then sent to the controller by the pressure detection device. The real-time temperature value is detected and obtained by the temperature detection device, and then the temperature value is sent to the controller by the temperature detection device. It should be noted that, in the process of recovering the refrigerant, "real-time" means that the pressure detecting device continuously detects the discharge pressure of the compressor 110, the temperature detecting device continuously detects the temperature of the middle part of the condenser 130, and the pressure detecting device and the temperature detecting device continuously send the real-time discharge pressure value and the real-time temperature value to the controller; in other words, the real-time discharge pressure value represents the current discharge pressure of the compressor 110, and the real-time temperature value represents the current temperature of the middle portion of the condenser 130.

Optionally, referring to fig. 5, before step S10, in order to ensure that the compressor 110 can execute the refrigerant recovery control method provided by the present application, the refrigerant recovery control method may further include:

step S05, determining whether the operation time of the compressor 110 reaches a fourth preset time.

It should be noted that, in the above-mentioned various cases, if the refrigerant in the two states of gas and liquid exists in the system 11 to be recovered, the recovery may be performed by first mixing and recovering the gaseous refrigerant and the liquid refrigerant, and under the condition that the recovery of the liquid refrigerant is completed, the recovery of the pure gaseous refrigerant is performed again; the refrigerant recovery control method can be applied to the process of pure gaseous refrigerant recovery. However, in the case where only the gaseous refrigerant exists in the system 11 to be recovered at the beginning and in the case where the recovery of the liquid refrigerant is inconvenient, the recovery of the pure gaseous refrigerant may be directly performed, and then the compressor 110 is in the standby state at this time, so that the refrigerant recovery control method provided by the present application is inconvenient to be directly performed. Based on this, by determining whether the operation time of the compressor 110 reaches the fourth preset time, the state of the compressor 110 at this time can be accurately determined, and it is convenient to control the compressor 110 to perform the refrigerant recovery control method.

And step S06, if yes, executing the step of receiving the real-time exhaust temperature value.

In other words, if the operation time of the compressor 110 reaches the fourth preset time, it means that the compressor 110 is in an operation state at this time, and thus the refrigerant recovery control method can be directly performed.

If not, the step S07 is to control the compressor 110 to be turned on, and control the operation frequency of the compressor 110 to increase the third frequency value every fifth preset time until the operation frequency of the compressor 110 is greater than or equal to the preset pressure value, and then execute the step of receiving the real-time exhaust pressure value.

That is, in the case where the compressor 110 is not provided with the refrigerant recovery control method that directly starts to be executed, the compressor 110 may be controlled to be operated up to the first time until the operation frequency of the compressor 110 is increased so that the discharge pressure of the compressor 110 reaches the preset pressure value, and then the execution of step S10 is started.

Optionally, the value of the fourth preset time provided above may be set according to the time required for the liquid refrigerant to complete recovery, and of course, may also be selected according to the time required for the compressor 110 to operate to a steady state. For example, the time required for completing recovery of the liquid refrigerant is set, and the value range of the fourth preset time may be 1h to 6h, in other words, the value of the fourth preset time may be 1h, 2h, 3h, 4h, 5h, 6h, or the like; for another example, the fourth preset time may be set according to a time required for the compressor 110 to operate to a steady state, and the value of the fourth preset time may be in a range of 10min to 30min, in other words, the value of the fourth preset time may be 10min, 12min, 15min, 18min, 20min, 25min, 30min, or the like. In addition, the range of the value of the fifth preset time may be 5s to 20s, in other words, the value of the fifth preset time may be 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, 20s, or the like. In addition, the value of the third frequency value may be 1Hz to 3Hz, in other words, the value of the third frequency value may be 1Hz, 2Hz, 3Hz, or the like.

Referring to fig. 4, in step S30, the compressor 110 is controlled to determine the operating frequency according to the real-time exhaust pressure value, the preset pressure value, the real-time temperature value and the preset temperature value.

Wherein, "determining" means that the controller can adjust the operating frequency of the compressor 110 according to the real-time exhaust pressure value, the preset pressure value, the real-time temperature value and the preset temperature value, so that the operating frequency of the compressor 110 is increased or decreased; of course, the current operating frequency of the compressor 110 may also be maintained, i.e., the current operating state of the compressor 110 may also be maintained.

The purpose of step S30 is to determine the operating frequency of the compressor 110 by the controller, so that the real-time exhaust pressure value can be made to approach the preset pressure value, thereby ensuring that the recovery speed of the refrigerant is optimal, avoiding excessive energy consumption, and simultaneously achieving the purposes of refrigerant recovery efficiency and energy saving.

The preset pressure value and the preset temperature value may be obtained by a developer performing an experiment before the refrigerant recovery system 10 leaves the factory and set in the controller. Based on the above, the recovery speed of the refrigerant may be optimized when the temperature of the middle portion of the condenser 130 reaches the preset temperature value, and at the same time, the discharge pressure of the compressor 110 reaches the preset pressure value when the temperature of the middle portion of the condenser 130 reaches the preset temperature value. In other words, if the temperature of the middle portion of the condenser 130 reaches the preset temperature value and the discharge pressure of the compressor 110 reaches the preset pressure value, this indicates that the recovery speed of the refrigerant is optimal, and excessive energy consumption is avoided. Therefore, the operation frequency of the compressor 110 is adjusted according to the preset pressure value and the preset temperature value to adjust the real-time exhaust temperature value and the real-time temperature value, so that the real-time exhaust pressure value approaches to the preset pressure value, thereby solving the technical problem that the energy consumption is excessive to be unfavorable for energy saving in order to improve the recovery efficiency of the refrigerant in the prior art.

Alternatively, the preset pressure value may have a value ranging from 2.93MPa to 2.97MPa, in other words, the preset pressure value may have a value of 2.93MPa, 2.94MPa, 2.95MPa, 2.96MPa, 2.97MPa, or the like. In addition, the preset temperature value may be in the range of 48℃to 56℃or, in other words, 48℃49℃50℃51℃52℃53℃54℃55℃56℃or the like. It should be noted that, the preset pressure value and the preset temperature value may be selected according to the actual displacement of the compressor 110, for example, in the case that the displacement of the compressor 110 is 27.5ML, the preset pressure value may be 2.95MPa, the preset temperature value may be 52 ℃.

In other words, during the refrigerant recovery process, the operation frequency of the compressor 110 affects the temperature of the refrigerant, and thus the temperature of the middle portion of the condenser 130, and the refrigerant recovery rate is related to the temperature of the middle portion of the condenser 130. And, in case that the temperature of the middle part of the condenser 130 reaches a preset temperature value, the recovery speed of the refrigerant reaches an optimum; if the operation frequency of the compressor 110 is continuously increased to increase the temperature of the middle portion of the condenser 130, the recovery rate of the refrigerant is not increased, but excessive energy consumption is caused, which is not beneficial to energy saving. In addition, in case that the middle portion of the condenser 130 reaches a preset temperature value, the discharge pressure of the compressor 110 reaches a preset pressure value. The control accuracy of controlling the operation frequency of the compressor 110 by only the temperature of the middle portion of the condenser 130 is low, and thus, the operation frequency of the compressor 110 is controlled by the real-time temperature value of the middle portion of the condenser 130 and the real-time discharge pressure value of the compressor 110, so that it is possible to adjust the recovery speed of the refrigerant to an optimal speed while preventing excessive consumption of energy. That is, the refrigerant recovery control method provided by the invention can solve the technical problems that in the prior art, in order to improve the recovery efficiency of the refrigerant, the energy consumption is excessive, and the energy saving is not facilitated.

Optionally, referring to fig. 6, in some embodiments of the present application, step S30 may include:

step S31, a first pressure threshold value and a second pressure threshold value are calculated according to a preset pressure value.

Wherein the first pressure threshold is greater than the second pressure threshold.

Step S32, a first temperature threshold and a second temperature threshold are calculated according to a preset temperature value.

Wherein the first temperature threshold is greater than the second temperature threshold.

Step S33, controlling the compressor 110 to determine the operation frequency according to the real-time exhaust pressure value, the real-time temperature value, the first pressure threshold value, the second pressure threshold value, the first temperature threshold value and the second temperature threshold value.

It should be noted that, since the detection of the discharge pressure of the compressor 110 has a certain error and a certain hysteresis, and similarly, the detection of the temperature of the middle portion of the condenser 130 has a certain error and a certain hysteresis, in order to prevent the control accuracy from being lowered due to the detection error and hysteresis, the first pressure threshold value, the second pressure threshold value, the first temperature threshold value, and the second temperature threshold value may be determined by the preset pressure value and the preset temperature value, and thus the control judgment may be performed by the section formed by the first pressure threshold value and the second pressure threshold value and the section formed by the first temperature threshold value and the second temperature threshold value, so that the effective control may be ensured, and the control accuracy may be improved.

Alternatively, the first pressure threshold and the second pressure threshold may be calculated as follows: the first pressure threshold value is obtained by adding the first preset value to the preset pressure value, and the second pressure threshold value is obtained by subtracting the second preset value from the preset pressure value. The manner in which the first temperature threshold and the second temperature threshold are calculated may be as follows: the first temperature threshold is obtained by adding the third preset value to the preset temperature value, and the second temperature threshold is obtained by subtracting the fourth preset value from the preset temperature value.

The range of the first preset value may be 0.05MPa to 0.2MPa, in other words, the value of the first preset value may be 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa, 0.1MPa, 0.11MPa, 0.12MPa, 0.13MPa, 0.14MPa, 0.15MPa, 0.16MPa, 0.17MPa, 0.18MPa, 0.19MPa, 0.2MPa, or the like. In addition, the value range of the second preset value may be 0.05MPa to 0.2MPa, in other words, the value of the second preset value may be 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa, 0.1MPa, 0.11MPa, 0.12MPa, 0.13MPa, 0.14MPa, 0.15MPa, 0.16MPa, 0.17MPa, 0.18MPa, 0.19MPa, 0.2MPa, or the like. The first preset value and the second preset value can be the same value. The third preset value may be in a range of 0.2 ℃ to 1 ℃, in other words, the third preset value may be 0.2 ℃, 0.3 ℃, 0.4 ℃, 0.5 ℃, 0.6 ℃, 0.7 ℃, 0.8 ℃, 0.9 ℃, 1 ℃ or the like. The value of the fourth preset value may be in the range of 0.2 ℃ to 1 ℃, in other words, the value of the fourth preset value may be 0.2 ℃, 0.3 ℃, 0.4 ℃, 0.5 ℃, 0.6 ℃, 0.7 ℃, 0.8 ℃, 0.9 ℃, 1 ℃ or the like. The third preset value and the fourth preset value can be the same.

It should be appreciated that in other embodiments of the present application, the first pressure threshold value and the second pressure threshold value may be calculated in other manners, for example, obtained by multiplying a preset pressure value by a specific coefficient, etc. Similarly, the first temperature threshold and the second temperature threshold may be calculated by other manners, for example, by obtaining a product of a preset temperature value and a specific coefficient, etc.

In an embodiment of the present application, referring to fig. 7, step S33 may include:

step S331, comparing at least one of the first pressure threshold value and the second pressure threshold value with a real-time exhaust pressure value.

Step S331 is intended to determine the magnitude relation between the two values of the first pressure threshold value and the second pressure threshold value and the real-time exhaust pressure value.

Step S332, comparing at least one of the first temperature threshold value and the second temperature threshold value with the real-time temperature value.

Step S332 is intended to determine the magnitude relationship between the two values of the first temperature threshold and the second temperature threshold and the real-time temperature value.

The comparison of at least one of the first pressure threshold value and the second pressure threshold value with the real-time exhaust pressure value is described. Wherein "at least one" means that, in some cases, the magnitude relationship between the real-time exhaust pressure value and the first and second pressure thresholds can be derived after comparing the real-time exhaust pressure value with one of the first and second pressure thresholds; for example, the first pressure threshold is less than the real-time exhaust pressure value and the second pressure threshold is greater than the real-time exhaust pressure value. In other cases, it may be desirable to compare the first pressure threshold value and the second pressure threshold value to the real-time exhaust pressure value to derive a magnitude relationship between the first pressure threshold value, the second pressure threshold value, and the real-time exhaust pressure value, e.g., the first pressure threshold value is greater than the real-time exhaust pressure value and the second pressure threshold value is less than the real-time exhaust pressure value.

Step S333, controlling the compressor 110 to adjust the operating frequency or controlling the compressor 110 to maintain the current operating frequency according to the magnitude relation between the first pressure threshold, the second pressure threshold and the real-time exhaust pressure value and the magnitude relation between the first temperature threshold, the second temperature threshold and the real-time temperature value.

After the magnitude relation between the first pressure threshold, the second pressure threshold and the real-time exhaust pressure value and the magnitude relation between the first temperature threshold, the second temperature threshold and the real-time temperature value are obtained in step S331 and step S332, the state of the current refrigerant recovery speed can be determined, so that the operation frequency of the compressor 110 can be determined, the refrigerant recovery speed can be ensured to be optimal, and excessive energy consumption can be avoided.

Optionally, referring to fig. 8, step S333 may include:

in step S301, if the real-time exhaust pressure value is greater than the first pressure threshold value, or the real-time temperature value is greater than the first temperature threshold value, the compressor 110 is controlled to reduce the operating frequency until the real-time exhaust pressure value is less than or equal to the preset pressure value and the real-time temperature value is less than or equal to the preset temperature value.

Optionally, in step S301, the manner of controlling the compressor 110 to reduce the operating frequency is: the operating frequency of the compressor 110 is controlled to decrease by a first frequency value every second preset time. The range of the second preset time may be 20s to 30s, in other words, the value of the second preset time may be 20s, 21s, 22s, 23s, 24s, 25s, 26s, 27s, 28s, 29s, or 30s. In addition, the value of the first frequency value may be 1Hz to 3Hz, in other words, the value of the first frequency value may be 1Hz, 2Hz, 3Hz, or the like.

Since there is a certain hysteresis in the change of the discharge pressure of the compressor 110 and the temperature of the middle part of the condenser 130 during the frequency reduction of the compressor 110, the operation frequency of the compressor 110 is controlled to be reduced in an intermittent manner, so that the control accuracy is prevented from being reduced due to the excessively high adjustment speed of the operation frequency.

In step S302, if the real-time exhaust pressure value is smaller than the second pressure threshold value, or the real-time temperature value is smaller than the second temperature threshold value, the compressor 110 is controlled to increase the operating frequency until the real-time exhaust pressure value is greater than or equal to the preset pressure value and the real-time temperature value is greater than or equal to the preset temperature value.

Optionally, in step S302, the manner of controlling the compressor 110 to raise the operating frequency is: the operating frequency of the compressor 110 is controlled to be increased by a second frequency value every third preset time. The range of the third preset time may be 30s to 40s, in other words, the value of the third preset time may be 30s, 31s, 32s, 33s, 34s, 35s, 36s, 37s, 38s, 39s, 40s, or the like. The value of the second frequency value may be 1Hz to 3Hz, in other words, the value of the second frequency value may be 1Hz, 2Hz, 3Hz, or the like.

It should be noted that, since the temperature rising speed of the condenser 130 in the up-conversion state of the compressor 110 is faster than the temperature rising speed of the condenser 130 in the down-conversion state of the compressor 110, setting the third preset time to be greater than the second preset time based on this can prevent the temperature rising from being too fast to cause the operating frequency of the compressor 110 to fluctuate. Additionally, in some embodiments of the application, the first frequency value and the second frequency value may be chosen to be the same value.

In step S303, if the real-time exhaust pressure value is less than or equal to the first pressure threshold and greater than or equal to the second pressure threshold, the compressor 110 is controlled to maintain the current operation frequency until the recovery of the refrigerant is completed.

When the real-time discharge pressure value is greater than the first pressure threshold value or the real-time temperature value is greater than the first temperature threshold value, it means that the refrigerant recovery rate is optimal at this time, but the operation frequency of the compressor 110 is too high, so that the energy is excessively consumed, and accordingly, the operation frequency of the compressor 110 needs to be reduced to prevent the excessive consumption of the energy. In order to prevent the condition that the real-time discharge pressure value is too small due to the over-adjustment and the real-time temperature value is too small due to the over-adjustment, thereby causing the refrigerant recovery speed to be reduced, the adjustment is suspended when the operation frequency of the compressor 110 is controlled to be reduced such that the real-time discharge pressure value is less than or equal to the preset pressure value and the real-time temperature value is less than or equal to the preset temperature value, so as to prevent the refrigerant recovery speed from being reduced.

If the real-time discharge pressure value is smaller than the second pressure threshold value or if the real-time temperature value is smaller than the second temperature threshold value, it means that the refrigerant recovery rate at this time has not reached the optimal rate, and therefore, it is necessary to increase the operation frequency of the compressor 110 to increase the refrigerant recovery rate. In order to prevent excessive energy consumption caused by excessive increase of the operation frequency of the compressor 110 due to excessive adjustment, the adjustment is suspended when the operation frequency of the compressor 110 is controlled to increase such that the real-time discharge pressure value is greater than or equal to the preset pressure value and the real-time temperature value is greater than or equal to the preset temperature value, so as to prevent excessive energy consumption caused by excessive increase of the operation frequency of the compressor 110.

Of course, when the real-time exhaust pressure value is smaller than or equal to the first pressure threshold and greater than or equal to the second pressure threshold, it indicates that the real-time exhaust pressure value is already in a state approaching to the preset pressure value at this time, so that the compressor 110 can be controlled to maintain the current operation state until the recovery of the refrigerant is completed, and the problems of energy consumption and energy saving are avoided while the recovery efficiency of the refrigerant is improved.

After adjusting the operation frequency of the compressor 110, in order to ensure the control accuracy, the refrigerant recovery control method may further include:

step S334, after controlling the compressor 110 to adjust the operation frequency, controlling the compressor 110 to operate for a first preset time, returning to the step of re-performing the comparison of at least one of the first pressure threshold value and the second pressure threshold value with the real-time exhaust pressure value, and the step of comparing at least one of the first temperature threshold value and the second temperature threshold value with the real-time temperature value.

In other words, after the operation frequency of the compressor 110 is adjusted in step S333, in order to determine whether the operation frequency of the compressor 110 is adjusted in place, steps S301 and S302 may be re-executed to determine the state in which the real-time discharge pressure value and the real-time temperature value are located, thereby determining the refrigerant recovery rate at this time and whether there is an excessive consumption of energy.

If the real-time exhaust pressure value and the real-time temperature value have not reached the values approaching the preset pressure value and the values approaching the preset temperature value, the operation frequency of the compressor 110 may be adjusted again, in other words, step S333 is repeatedly performed, so as to adjust the operation frequency of the compressor 110 in place, thereby ensuring that the recovery speed of the refrigerant can be adjusted to the optimum value, and effectively preventing excessive consumption of energy. Based on this, the operation frequency of the compressor 110 can be precisely adjusted to achieve the condition that the refrigerant recovery speed is optimal and the energy is not excessively consumed by the multiple adjustments.

Of course, in some cases, after repeatedly executing the step S333 a plurality of times, the operation frequency of the compressor 110 cannot always reach a state that can enable the real-time discharge pressure value to be between the first pressure threshold value and the second pressure threshold value, at this time, referring to fig. 9, in order to prevent the operation frequency of the compressor 110 from repeatedly fluctuating, the refrigerant recovery control method may further include:

step S1, each time the continuously controlled compressor 110 completes one time of increasing the operating frequency and one time of decreasing the operating frequency, counting is performed.

In other words, in the case where step S301 and step S302 are continuously performed and the execution of step S301 and the execution of step S302 are completed, counting is performed once.

Step S2, if the count reaches the preset number of times, after the operation frequency of the compressor 110 is controlled to be increased, the operation of the compressor 110 is controlled to be performed with the increased operation frequency until the recovery of the refrigerant is completed.

Alternatively, the preset number of times may take on a value of 1 to 5 times, in other words, the preset number of times may be 1, 2, 3, 4 or 5 times.

In the case that the count reaches the preset number, it indicates that the operation frequency of the compressor 110 has been repeatedly adjusted a plurality of times. After that, if the compressor 110 performs step S301, step S334 may be continued; if the compressor 110 performs step S301, the operation of the compressor 110 may be controlled at the operation frequency after the operation frequency of the compressor 110 is adjusted in step S302. At this time, the refrigerant recovery speed can be ensured to reach the best so as to ensure that the refrigerant recovery is completed rapidly; and at the same time, damage to the compressor 110 caused by repeated shifting of the operating frequency of the compressor 110 can be avoided.

In summary, in the refrigerant recovery system 10 and the refrigerant recovery control method according to the embodiments of the present application, the operation frequency of the compressor 110 affects the temperature of the refrigerant during the refrigerant recovery process, and the temperature of the middle portion of the condenser 130 is affected, based on which the recovery speed of the refrigerant is related to the temperature of the middle portion of the condenser 130. And, in case that the temperature of the middle part of the condenser 130 reaches a preset temperature value, the recovery speed of the refrigerant reaches an optimum; if the operation frequency of the compressor 110 is continuously increased to increase the temperature of the middle portion of the condenser 130, the recovery rate of the refrigerant is not increased, but excessive energy consumption is caused, which is not beneficial to energy saving. In addition, in case that the middle portion of the condenser 130 reaches a preset temperature value, the discharge pressure of the compressor 110 reaches a preset pressure value. The control accuracy of controlling the operation frequency of the compressor 110 by only the temperature of the middle portion of the condenser 130 is low, and thus, the operation frequency of the compressor 110 is controlled by the real-time temperature value of the middle portion of the condenser 130 and the real-time discharge pressure value of the compressor 110, so that it is possible to adjust the recovery speed of the refrigerant to an optimal speed while preventing excessive consumption of energy. That is, the refrigerant recovery control method provided by the application can solve the technical problems that in the prior art, in order to improve the recovery efficiency of the refrigerant, the energy consumption is excessive, and the energy saving is not facilitated.

In order to execute the possible steps of the refrigerant recovery control method provided in the above embodiments, referring to fig. 10, fig. 10 is a schematic functional block diagram of a refrigerant recovery control device 20 according to an embodiment of the application. The refrigerant recovery control device 20 is applied to the refrigerant recovery system 10, and the refrigerant recovery control device 20 provided by the embodiment of the application is used for executing the refrigerant recovery control method. It should be noted that, the basic principle and the technical effects of the refrigerant recovery control device 20 provided in this embodiment are substantially the same as those of the above embodiment, and for brevity, reference should be made to the corresponding contents of the above embodiment.

The refrigerant recovery control device 20 includes a first receiving module 21, a second receiving module 22, and a control module 23.

The first receiving module 21 is configured to receive a real-time discharge pressure value, which represents a real-time pressure of the refrigerant in the discharge pipe of the compressor 110.

Alternatively, the first receiving module 21 may be configured to perform step S10 in the foregoing respective figures, so as to achieve a corresponding technical effect.

The second receiving module 22 is configured to receive a real-time temperature value, which is indicative of a real-time temperature of the middle of the condenser 130.

Alternatively, the second receiving module 22 may be configured to perform step S20 in the foregoing respective figures, so as to achieve a corresponding technical effect.

Alternatively, the first receiving module 21 and the second receiving module 22 may be the same module.

The control module 23 is configured to control the compressor 110 to determine the operating frequency according to the real-time exhaust pressure value, the preset pressure value, the real-time temperature value and the preset temperature value, so that the real-time exhaust pressure value approaches the preset pressure value.

Optionally, the control module 23 is configured to execute step S30 and the sub-steps thereof in the foregoing respective figures, so as to achieve a corresponding technical effect.

Of course, the control module 23 may also execute step S1, step S2, step S05, step S06, and the like in the respective figures, and achieve the corresponding technical effects.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The apparatus embodiments described above are merely illustrative, for example, of the flowcharts and block diagrams in the figures that illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, functional modules in the embodiments of the present invention may be integrated together to form a single part, or each module may exist alone, or two or more modules may be integrated to form a single part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims

1. The refrigerant recovery control method is applied to a refrigerant recovery system and is characterized in that the refrigerant recovery system comprises a recovery pipeline, a liquid refrigerant recovery branch and a mixing branch, one end of the recovery pipeline is connected to a system to be recovered, and the other end of the recovery pipeline is connected to a recovery container; the recovery pipeline is provided with a compressor and a condenser, and the compressor is used for extracting a gaseous refrigerant in the system to be recovered during operation and guiding the refrigerant to the condenser so as to guide the refrigerant into the recovery container; one end of the liquid refrigerant recovery branch is connected to the system to be recovered, the other end of the liquid refrigerant recovery branch is connected to the recovery container, and a second electromagnetic valve is arranged on the liquid refrigerant recovery branch and is used for opening or closing the liquid refrigerant recovery branch; one end of the mixing branch is connected to the recovery pipeline and is connected between a Laval nozzle and a condenser in the recovery pipeline; the other end is connected with a liquid refrigerant recovery branch and is connected between the second electromagnetic valve and the system to be recovered;

the refrigerant recovery control method comprises the following steps:

controlling the compressor to determine an operating frequency according to the real-time exhaust pressure value, a preset pressure value, a real-time temperature value and a preset temperature value so as to enable the real-time exhaust pressure value to approach the preset pressure value;

wherein, before the step of receiving the real-time exhaust pressure value, the second electromagnetic valve is controlled to be closed, and the mixing branch is controlled to be conducted.

2. The refrigerant recovery control method according to claim 1, wherein the step of controlling the compressor to determine the operating frequency according to the real-time discharge pressure value, the preset pressure value, the real-time temperature value, and the preset temperature value includes:

3. The refrigerant recovery control method according to claim 2, wherein the step of controlling the compressor to adjust the operating frequency in accordance with the real-time discharge pressure value, the real-time temperature value, the first pressure threshold value, the second pressure threshold value, the first temperature threshold value, and the second temperature threshold value includes:

4. The refrigerant recovery control method according to claim 3, wherein the step of controlling the compressor to adjust an operation frequency or controlling the compressor to maintain a current operation frequency according to a magnitude relation among the first pressure threshold value, the second pressure threshold value, and the real-time discharge pressure value, and a magnitude relation among the first temperature threshold value, the second temperature threshold value, and the real-time temperature value comprises: if the real-time exhaust pressure value is greater than the first pressure threshold value or the real-time temperature value is greater than the first temperature threshold value, controlling the compressor to reduce the operating frequency until the real-time exhaust pressure value is less than or equal to the preset pressure value and the real-time temperature value is less than or equal to the preset temperature value;

5. The refrigerant recovery control method according to claim 4, wherein the step of controlling the compressor to reduce an operation frequency includes:

wherein the second preset time is less than the third preset time.

6. The refrigerant recovery control method according to claim 4, further comprising:

7. The refrigerant recovery control method according to claim 2, wherein the step of calculating the first pressure threshold value and the second pressure threshold value according to the preset pressure value includes:

8. The refrigerant recovery control method according to any one of claims 1 to 7, characterized in that the refrigerant recovery control method further comprises, before receiving the real-time discharge pressure value:

if yes, executing the step of receiving the real-time exhaust pressure value;

9. The refrigerant recovery control device is applied to a refrigerant recovery system and is characterized by comprising a recovery pipeline, a liquid refrigerant recovery branch and a mixing branch, wherein one end of the recovery pipeline is connected to a system to be recovered, and the other end of the recovery pipeline is connected to a recovery container; the recovery pipeline is provided with a compressor and a condenser, and the compressor is used for extracting a gaseous refrigerant in the system to be recovered during operation and guiding the refrigerant to the condenser so as to guide the refrigerant into the recovery container; one end of the liquid refrigerant recovery branch is connected to the system to be recovered, the other end of the liquid refrigerant recovery branch is connected to the recovery container, and a second electromagnetic valve is arranged on the liquid refrigerant recovery branch and is used for opening or closing the liquid refrigerant recovery branch; one end of the mixing branch is connected to the recovery pipeline and is connected between a Laval nozzle and a condenser in the recovery pipeline; the other end is connected with a liquid refrigerant recovery branch and is connected between the second electromagnetic valve and the system to be recovered;

The refrigerant recovery control device includes:

the second receiving module is used for receiving a real-time temperature value, and the real-time temperature value represents the real-time temperature of the middle part of the condenser;

the control module is used for controlling the compressor to determine the operating frequency according to the real-time exhaust pressure value, the preset pressure value, the real-time temperature value and the preset temperature value so as to enable the real-time exhaust pressure value to approach the preset pressure value; the control module is also used for controlling the second electromagnetic valve to be closed and controlling the mixing branch to be conducted before the step of receiving the real-time exhaust pressure value.

10. The refrigerant recovery system is characterized by comprising a recovery pipeline, a liquid refrigerant recovery branch and a mixing branch, wherein one end of the recovery pipeline is connected to a system to be recovered, and the other end of the recovery pipeline is connected to a recovery container; the recovery pipeline is provided with a compressor and a condenser, and the compressor is used for extracting a gaseous refrigerant in the system to be recovered during operation and guiding the refrigerant to the condenser so as to guide the refrigerant into the recovery container; one end of the liquid refrigerant recovery branch is connected to the system to be recovered, the other end of the liquid refrigerant recovery branch is connected to the recovery container, and a second electromagnetic valve is arranged on the liquid refrigerant recovery branch and is used for opening or closing the liquid refrigerant recovery branch; one end of the mixing branch is connected to the recovery pipeline and is connected between a Laval nozzle and a condenser in the recovery pipeline; the other end is connected with a liquid refrigerant recovery branch and is connected between the second electromagnetic valve and the system to be recovered; the refrigerant recovery system further comprises a pressure detection device, a temperature detection device and a controller; the pressure detection device is arranged on an exhaust pipe of the compressor so as to detect a real-time exhaust pressure value of the exhaust pipe; the temperature detection device is arranged in the middle of the condenser to detect the real-time temperature value of the condenser; the pressure detection device and the temperature detection device are electrically connected with a controller, and the controller is used for receiving the real-time exhaust pressure value and the real-time temperature value and executing the refrigerant recovery control method according to any one of claims 1-8.