Refrigeration system and control method for a refrigeration system

Abstract

The application provides a refrigeration system and a control method of the refrigeration system. The refrigeration system comprises a controller, a pipeline, a compressor, a liquid storage tank and a heat exchanger connected in series through the pipeline. The pipeline comprises an inlet pipeline, an outlet pipeline and a control pipeline connecting the inlet pipeline and the outlet pipeline. The inlet pipeline is provided with a first valve electrically connected with the controller. The outlet pipeline is provided with a second valve electrically connected with the controller. The control pipeline is provided with a third valve electrically connected with the controller. The control method of the refrigeration system comprises: controlling the refrigeration system to enter an increase / decrease adjustment state according to the state of the refrigeration system. In the increase / decrease adjustment state, one of the first valve and the second valve is opened and the other is closed, and the third valve is closed, so that the circulating amount of refrigerant in the compressor and the heat exchanger is increased or decreased. The refrigeration system can adjust the circulating amount of refrigerant in the refrigeration system according to the state of the refrigeration system, and the refrigeration effect is good.

Description

TECHNICAL FIELD

[0001] The present specification relates to the mechanical field, and in particular to a refrigeration system and a control method of the refrigeration system. BACKGROUND

[0002] When the refrigeration system has been designed, if the refrigeration capacity can be further improved and the refrigeration speed can be accelerated after the size of the heat exchanger reaches the limit due to the space installation problem, the customer satisfaction can be greatly improved.

[0003] On the other hand, when the refrigeration system operates at a low ambient temperature, the exhaust pressure is often low, which affects the refrigeration effect. When the ambient temperature is high, the temperature in the box is also high, and at this time, the load is large, and there is a high-voltage tripping risk. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a refrigeration system and a control method of the refrigeration system, which can adjust the refrigerant circulation amount in the refrigeration system according to the state of the refrigeration system, and has good refrigeration effect.

[0005] One aspect of the embodiments of the present application provides a refrigeration system, which comprises a controller, a pipeline, and a compressor, a liquid storage tank and a heat exchanger connected in series through the pipeline, the liquid storage tank comprises a liquid storage tank inlet and a liquid storage tank outlet, the pipeline comprises an inlet pipeline connected to the liquid storage tank inlet, an outlet pipeline connected to the liquid storage tank outlet, and a control pipeline connecting the inlet pipeline and the outlet pipeline, the liquid storage tank is connected in series with the compressor and the heat exchanger through the inlet pipeline and the outlet pipeline; the inlet pipeline is provided with a first valve electrically connected to the controller, the outlet pipeline is provided with a second valve electrically connected to the controller, and the control pipeline is provided with a third valve electrically connected to the controller.

[0006] The controller is used to control the refrigeration system to enter an increase / decrease adjustment state according to the state of the refrigeration system, wherein in the increase / decrease adjustment state, one of the first valve and the second valve is opened and the other is closed, and the third valve is closed, so that the refrigerant circulation amount flowing in the compressor and the heat exchanger is increased or decreased.

[0007] Optionally, the increase / decrease adjustment state comprises an increase adjustment state and a decrease adjustment state.

[0008] The controller is configured to control the refrigeration system to enter an increasing adjustment state or a decreasing adjustment state according to a state of the refrigeration system, wherein in the increasing adjustment state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount; in the decreasing adjustment state, the first valve is controlled to be opened, and the second valve and the third valve are controlled to be closed, so as to decrease the refrigerant circulation amount.

[0009] Optionally, the controller is further configured to control the refrigeration system to enter an adjusting state.

[0010] When the refrigeration system switches to the adjusting state, the controller is further configured to control the refrigeration system to enter an increasing and decreasing adjustment state within a first time length.

[0011] The controller is further configured to, after the first time length ends, acquire a state of the refrigeration system every interval of a preset adjusting time length, determine whether to continue to increase and decrease the refrigerant circulation amount, and if the refrigerant circulation amount needs to be continued to be increased and decreased, control the refrigeration system to be in the increasing and decreasing adjustment state within a second time length.

[0012] Optionally, the controller is configured to, when the refrigeration system is in the increasing and decreasing adjustment state, control one of the first valve and the second valve to be opened and the other to be closed, and control the third valve to be alternately opened and closed repeatedly for multiple times, and the controller is configured to control an increasing and decreasing amount and an increasing and decreasing speed of the refrigerant circulation amount according to a number of times of closing and a switching frequency of the third valve.

[0013] Optionally, the controller is configured to acquire a return air temperature of the refrigeration system, and if the return air temperature is greater than or equal to a set temperature, control the refrigeration system to enter the adjusting state, and control the refrigeration system to enter the increasing adjustment state within a first time length, and the controller is further configured to, after the first time length ends and the refrigeration system returns to the adjusting state, acquire a supercooling degree of an outlet of a condenser of the refrigeration system every interval of a preset adjusting time length, and if the supercooling degree is less than a first threshold, determine that the refrigerant circulation amount needs to be continued to be increased, and control the refrigeration system to be in the increasing adjustment state within a second time length.

[0014] Optionally, the controller is configured to acquire an ambient temperature and an exhaust pressure of the refrigeration system, and if the ambient temperature is less than a set ambient temperature and the exhaust pressure is less than or equal to a set exhaust pressure, control the refrigeration system to enter the adjusting state, and control the refrigeration system to enter the increasing adjustment state within a first time length, and the controller is further configured to acquire the exhaust pressure of the refrigeration system every interval of a preset adjusting time length, and if the exhaust pressure is less than or equal to the set exhaust pressure, determine that the refrigerant circulation amount needs to be continued to be increased, and control the refrigeration system to be in the increasing adjustment state within a second time length.

[0015] Optionally, the controller is configured to acquire an ambient temperature and a return air temperature of the refrigeration system, and if the ambient temperature is greater than or equal to a set ambient temperature and the return air temperature is greater than or equal to a set temperature, control the refrigeration system to enter an adjustment state, and in a first time period, control the refrigeration system to enter a decreasing adjustment state; the controller is further configured to, after the first time period ends and the refrigeration system resumes the adjustment state, acquire an exhaust pressure of the refrigeration system every interval of a preset adjustment time, and if the exhaust pressure is greater than a set exhaust pressure, determine that the refrigerant circulation amount needs to be continuously decreased, and control the refrigeration system to be in the decreasing adjustment state in a second time period.

[0016] Optionally, the controller is further configured to, in the adjustment state, control an evaporative fan of the refrigeration system to operate at a minimum speed; and / or

[0017] the controller is further configured to, in the adjustment state, control the speed of the compressor to be reduced or remain unchanged.

[0018] Optionally, an end of the outlet pipeline connected to the liquid storage tank is close to the bottom of the liquid storage tank relative to the top of the liquid storage tank; and / or

[0019] an end of the inlet pipeline connected to the liquid storage tank is close to the top of the liquid storage tank relative to the bottom of the liquid storage tank.

[0020] Another aspect of the present application also provides a control method of a refrigeration system, the refrigeration system comprising a controller, a pipeline, and a compressor, a liquid storage tank, and a heat exchanger connected in series through the pipeline, the liquid storage tank comprising a liquid storage tank inlet and a liquid storage tank outlet, the pipeline comprising an inlet pipeline connected to the liquid storage tank inlet, an outlet pipeline connected to the liquid storage tank outlet, and a control pipeline connecting the inlet pipeline and the outlet pipeline, the liquid storage tank being connected in series with the compressor and the heat exchanger through the inlet pipeline and the outlet pipeline; the inlet pipeline is provided with a first valve electrically connected to the controller, the outlet pipeline is provided with a second valve electrically connected to the controller, and the control pipeline is provided with a third valve electrically connected to the controller; the control method comprises:

[0021] controlling the refrigeration system to enter an increasing and decreasing adjustment state according to the state of the refrigeration system, wherein in the increasing and decreasing adjustment state, one of the first valve and the second valve is opened and the other is closed, and the third valve is closed at the same time, so that the refrigerant circulation amount flowing in the compressor and the heat exchanger is increased or decreased.

[0022] Optionally, the increasing and decreasing adjustment state comprises an increasing adjustment state and a decreasing adjustment state;

[0023] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0024] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0025] controlling the refrigeration system to enter a decrease-regulation state according to the state of the refrigeration system, wherein in the decrease-regulation state, the first valve is controlled to be opened, and the second valve and the third valve are controlled to be closed, so as to decrease the refrigerant circulation amount.

[0026] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0027] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0028] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0029] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0030] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0031] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0032] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0033] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0034] controlling the refrigeration system to enter an increase-regulation state according to the state of the refrigeration system, wherein in the increase-regulation state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so as to increase the refrigerant circulation amount;

[0035] The state of the refrigeration system is obtained every preset adjustment interval, and it is determined whether the refrigerant circulation amount needs to continue to be increased or decreased. If the refrigerant circulation amount needs to continue to be increased or decreased, the refrigeration system is controlled to be in the increasing or decreasing adjustment state for a second time interval, including:

[0036] The supercooling degree of the condenser outlet of the refrigeration system is obtained every preset adjustment interval. If the supercooling degree is less than a first threshold value, it is determined that the refrigerant circulation amount needs to continue to be increased, and the refrigeration system is controlled to be in the increasing adjustment state for a second time interval.

[0037] Optionally, the increasing or decreasing adjustment state includes an increasing adjustment state. In the increasing adjustment state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so that the refrigerant circulation amount is increased.

[0038] The state of the refrigeration system is obtained every preset adjustment interval, and it is determined whether the refrigerant circulation amount needs to continue to be increased or decreased. If the refrigerant circulation amount needs to continue to be increased or decreased, the refrigeration system is controlled to be in the increasing or decreasing adjustment state for a second time interval, including:

[0039] The refrigeration system is controlled to be in the increasing or decreasing adjustment state for a first time interval, including:

[0040] The refrigeration system is controlled to be in the increasing adjustment state for a first time interval.

[0041] The state of the refrigeration system is obtained every preset adjustment interval, and it is determined whether the refrigerant circulation amount needs to continue to be increased or decreased. If the refrigerant circulation amount needs to continue to be increased or decreased, the refrigeration system is controlled to be in the increasing or decreasing adjustment state for a second time interval, including:

[0042] The state of the refrigeration system is obtained every preset adjustment interval, and it is determined whether the refrigerant circulation amount needs to continue to be increased or decreased. If the refrigerant circulation amount needs to continue to be increased or decreased, the refrigeration system is controlled to be in the increasing or decreasing adjustment state for a second time interval, including:

[0043] Optionally, the increasing or decreasing adjustment state includes a decreasing adjustment state. In the decreasing adjustment state, the first valve is controlled to be opened, and the second valve and the third valve are controlled to be closed, so that the refrigerant circulation amount is decreased.

[0044] The method comprises: obtaining an ambient temperature and a return air temperature of the refrigeration system; and controlling the refrigeration system to enter an adjustment state if the ambient temperature is greater than or equal to a set ambient temperature and the return air temperature is greater than or equal to a set temperature.

[0045] The method comprises: controlling the refrigeration system to enter an increase-decrease adjustment state in a first time period.

[0046] The method comprises: controlling the refrigeration system to enter a decrease adjustment state in a first time period.

[0047] The method comprises: obtaining a state of the refrigeration system every preset adjustment time period; determining whether the refrigerant circulation amount needs to be continuously increased or decreased; and controlling the refrigeration system to be in the increase-decrease adjustment state in a second time period if the refrigerant circulation amount needs to be continuously increased or decreased.

[0048] The method comprises: obtaining an exhaust pressure of the refrigeration system every preset adjustment time period; determining that the refrigerant circulation amount needs to be continuously decreased if the exhaust pressure is greater than a set exhaust pressure; and controlling the refrigeration system to be in the decrease adjustment state in a second time period.

[0049] Optionally, the method further comprises:

[0050] In the adjustment state, the method comprises: controlling an evaporative fan of the refrigeration system to operate at a minimum speed; and / or controlling a rotation speed of the compressor to be reduced or kept unchanged.

[0051] The refrigeration system of the present application comprises a liquid storage tank, and the refrigerant circulation amount flowing in the compressor and the heat exchanger can be increased or decreased by controlling one of the first valve and the second valve to be opened and the other to be closed and controlling the third valve to be closed. The control method of the refrigeration system of the present application comprises controlling the increase or decrease of the refrigerant circulation amount according to the state of the refrigeration system, thereby enhancing the stability of the system and improving the satisfaction of the user.

[0052] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present specification. BRIEF DESCRIPTION OF DRAWINGS

[0053] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present specification and serve to explain the principles of the present specification together with the specification.

[0054] Figure 1 FIG. 1 is a structural schematic diagram of a refrigeration system according to an embodiment of the present application;

[0055] Figure 2 FIG. 2 is a control timing diagram of a control method of a refrigeration system according to an embodiment of the present application; and

[0056] Figure 3 Control timing diagram for another embodiment of the control method of the refrigeration system of the present application;

[0057] Figure 4 Control timing diagram for yet another embodiment of the control method of the refrigeration system of the present application.

[0058] Wherein, the refrigeration system 1, the pipeline 2, the liquid storage tank 3, the compressor 4, the heat exchanger 5, the liquid storage tank inlet 31, the liquid storage tank outlet 32, the inlet pipeline 21, the outlet pipeline 22, the control pipeline 23, the first valve 61, the second valve 62, the third valve 63. DETAILED DESCRIPTION

[0059] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description of the exemplary embodiments is intended to apply to various alternative embodiments as well. It is to be understood that features illustrated or described as part of one embodiment can be provided with one or more of the other embodiments. Variations to embodiments can be made and would be obvious to those having the benefit of this disclosure. Accordingly, the following description is not intended to limit the scope of the claims.

[0060] The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to limit the description. As used in the description and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0061] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various information, these terms are not intended to denote a temporal or chronological order. Rather, these terms are used only as a shorthand notation to first, second, third, etc. information. For example, a first information can also be termed a second information, and similarly, a second information can also be termed a first information, without departing from the scope of the present description. Depending on the context, the word "if' as used herein can be interpreted to mean "when" or "in response to determining" or "in response to a determination."

[0062] The embodiments of the present description will be described in detail.

[0063] When the refrigeration system 1 has been designed, due to space installation problems, if the heat exchanger 5 size reaches the limit, further improving the refrigeration capacity and accelerating the refrigeration speed can greatly help to improve customer satisfaction.

[0064] When the refrigeration system 1 is running at low ambient temperature, the exhaust pressure is usually low. At this time, the refrigerant circulation amount of the refrigeration system 1 can be increased, so that a large amount of liquid refrigerant is accumulated in the heat exchanger 5 to achieve the purpose of liquid sealing, and the condensing pressure is increased. The unit is running in the output power allowed by the compressor 4.

[0065] When the ambient temperature is high, the temperature in the box is also high, and the load is large at this time, which has the risk of high-voltage tripping. At this time, the refrigerant circulation amount in the system can be reduced to achieve the purpose of pressure relief, so that the unit can withstand the initial harsh working conditions.

[0066] Figure 1 For the structure diagram of the refrigeration system of an embodiment of the present application, please refer to Figure 1 The present application provides a refrigeration system 1, which comprises a controller, a pipeline 2, and a compressor 4, a liquid storage tank 3 and a heat exchanger 5 connected in series through the pipeline 2. The liquid storage tank 3 comprises a liquid storage tank inlet 31 and a liquid storage tank outlet 32. The pipeline 2 comprises an inlet pipeline 21 connected to the liquid storage tank inlet 31, an outlet pipeline 22 connected to the liquid storage tank outlet 32, and a control pipeline 23 connecting the inlet pipeline 21 and the outlet pipeline 22. The liquid storage tank 3 is connected in series with the compressor 4 and the heat exchanger 5 through the inlet pipeline 21 and the outlet pipeline 22. The inlet pipeline 21 is provided with a first valve 61 electrically connected to the controller, the outlet pipeline 22 is provided with a second valve 62 electrically connected to the controller, and the control pipeline 23 is provided with a third valve 63 electrically connected to the controller. The inlet and outlet of the liquid storage tank 3 of the refrigeration system 1 of the present application are provided with valves, so that the circulation amount of the refrigerant in the refrigeration system 1 can be adjusted by opening and closing the first valve 61 located in the inlet pipeline 21 and the second valve 62 located in the outlet pipeline 22. In the normal working process, the first valve 61 and the second valve 62 are both opened. In some embodiments, if it is necessary to increase the refrigerant amount in the circulation of the refrigeration system 1, the controller is used to close the first valve 61 and open the second valve 62. Because there is still pressure in the outlet pipeline 22, the refrigerant in the liquid storage tank 3 will still be sucked into the circulation of the refrigeration system 1 due to the pressure difference. At this time, when it returns to the working state, the refrigerant amount in the system is increased. In other embodiments, if it is necessary to reduce the refrigerant amount in the circulation of the refrigeration system 1, the controller is used to close the second valve 62 and open the first valve 61. Because there is still pressure in the inlet pipeline 21, the refrigerant in the circulation flows into the liquid storage tank 3. At this time, when it returns to the working state, the refrigerant amount in the system is reduced.

[0067] When one of the first valve 61 and the second valve 62 is opened and the other is closed to increase and decrease the circulation amount in the refrigeration system 1, because the circulation pressure in the refrigeration system 1 is large, the refrigerant amount in the refrigeration system 1 will change greatly in a very short time. In some embodiments, the control pipeline 23 of the refrigeration system 1 of the present application can not be used, and the first valve 61 and the second valve 62 are directly controlled to open and close to realize the increase and decrease of the refrigerant amount in the refrigeration system 1.

[0068] In some embodiments, the controller is configured to control the refrigeration system 1 to enter a step-up / down regulation state according to the state of the refrigeration system 1, wherein in the step-up / down regulation state, one of the first valve 61 and the second valve 62 is controlled to be open and the other is controlled to be closed, and the third valve 63 is controlled to be closed, so as to step up / down the circulating amount of refrigerant in the compressor 4 and the heat exchanger 5. Since the resistance in the control pipeline 23 is smaller when the third valve 63 is open, the refrigerant will flow from the control pipeline 23 without passing through the inlet pipeline 21, the liquid accumulator 3 and the outlet pipeline 22, and in this case, the amount of refrigerant in the circulation remains unchanged. Thus, when the controller controls one of the first valve 61 and the second valve 62 to be open and the other to be closed to step up / down the circulating amount in the refrigeration system 1, the controller can control the step-up / down amount of refrigerant by controlling the third valve 63 to be open and closed. Thus, compared with controlling the first valve 61 and the second valve 62 simultaneously, controlling only the third valve 63 is more accurate. In the case where the pressure in the pipeline 2 does not change greatly, the increase and decrease of the amount of refrigerant can be considered to be uniform, and in this case, the length of time when one of the first valve 61 and the second valve 62 is controlled to be open and the other is controlled to be closed, and the third valve 63 is controlled to be closed, can achieve the control of the increase / decrease amount of refrigerant in the refrigeration system 1.

[0069] Please refer to Figure 1 In the illustrated embodiment, the end of the outlet pipeline 22 connected to the liquid accumulator 3 is close to the bottom of the liquid accumulator 3 relative to the top of the liquid accumulator 3. The end of the inlet pipeline 21 connected to the liquid accumulator 3 is close to the top of the liquid accumulator 3 relative to the bottom of the liquid accumulator 3. Thus, the end of the inlet pipeline 21 of the liquid accumulator 3 can be kept above the liquid level in the liquid accumulator 3, and the end of the outlet pipeline of the liquid accumulator 3 can be kept below the liquid level in the liquid accumulator 3, so as to ensure that when the first valve 61 is open and the second valve 62 is closed to reduce the amount of refrigerant, the refrigerant can flow smoothly into the liquid accumulator 3 through the inlet pipeline 21, and the end of the inlet pipeline 21 will not be blocked by the pressure difference in the bottle; at the same time, when the first valve 61 is closed and the second valve 62 is open to increase the amount of refrigerant, the refrigerant can flow into the circulation through the outlet pipeline 22, and the end of the outlet pipeline 22 is always immersed below the refrigerant level in the liquid accumulator 3.

[0070] Figure 2 The control timing diagram of an embodiment of the control method of the refrigeration system 1 of the present application; Figure 3 The control timing diagram of another embodiment of the control method of the refrigeration system 1 of the present application; Figure 4 The control timing diagram of still another embodiment of the control method of the refrigeration system 1 of the present application. Please refer to Figures 2-4Another aspect of the present application provides a control method of a refrigeration system 1, which is used in the refrigeration system 1 provided by the present application. The refrigeration system 1 comprises a controller, a pipeline 2, a compressor 4, a liquid storage tank 3 and a heat exchanger 5 connected in series through the pipeline 2. The liquid storage tank 3 comprises a liquid storage tank inlet 31 and a liquid storage tank outlet 32. The pipeline 2 comprises an inlet pipeline 21 connected to the liquid storage tank inlet 31, an outlet pipeline 22 connected to the liquid storage tank outlet 32 and a control pipeline 23 connecting the inlet pipeline 21 and the outlet pipeline 22. The liquid storage tank 3 is connected in series with the compressor 4 and the heat exchanger 5 through the inlet pipeline 21 and the outlet pipeline 22. The inlet pipeline 21 is provided with a first valve 61 electrically connected to the controller. The outlet pipeline 22 is provided with a second valve 62 electrically connected to the controller. The control pipeline 23 is provided with a third valve 63 electrically connected to the controller. The control method comprises: controlling the refrigeration system 1 to enter an increase / decrease adjustment state according to the state of the refrigeration system 1. In the increase / decrease adjustment state, one of the first valve 61 and the second valve 62 is opened and the other is closed, and the third valve 63 is closed, so that the circulating amount of the refrigerant flowing in the compressor 4 and the heat exchanger 5 is increased or decreased.

[0071] Thus, the control method of the refrigeration system 1 can realize the increase or decrease of the circulating amount of the refrigerant flowing in the compressor 4 and the heat exchanger 5 by controlling the opening and closing of the first valve 61, the second valve 62 and the third valve 63. The control method of the refrigeration system 1 can adjust the amount of the refrigerant in the refrigeration system 1 according to the state of the refrigeration system 1, so as to accelerate the refrigeration speed and improve the customer satisfaction.

[0072] In some embodiments, the increase / decrease adjustment state comprises an increase adjustment state and a decrease adjustment state. Please refer to the embodiments shown in Figures 2-4 Figure 2 and Figure 3 The embodiments shown in Figure 4 are the increase adjustment state, and the circulating amount of the refrigerant is increased. Figure 2 Figure 3 In the embodiments shown in Figure 4 , if the circulating amount of the refrigerant is to be decreased, the refrigeration system 1 can directly enter the decrease adjustment state after entering the adjustment state.

[0073] ​​In the increasing adjustment state, according to the state of the refrigeration system 1, the refrigeration system 1 is controlled to enter the increasing adjustment state, wherein in the increasing adjustment state, the second valve 62 is controlled to be opened, and the first valve 61 and the third valve 63 are controlled to be closed, so that the circulating amount of the refrigerant is increased. After the first valve 61 is closed and the second valve 62 is opened, the refrigerant in the liquid storage tank 3 is still sucked into the refrigeration system 1 due to the pressure difference, and when the system returns to the working state, the amount of the refrigerant in the system is increased.

[0074] In the decreasing adjustment state, according to the state of the refrigeration system 1, the refrigeration system 1 is controlled to enter the decreasing adjustment state, wherein in the decreasing adjustment state, the first valve 61 is controlled to be opened, and the second valve 62 and the third valve 63 are controlled to be closed, so that the circulating amount of the refrigerant is decreased. After the second valve 62 is closed and the first valve 61 is opened, the refrigerant in the circulation flows into the liquid storage tank 3 due to the pressure in the inlet pipe 21, and when the system returns to the working state, the amount of the refrigerant in the system is decreased.

[0075] In some embodiments, since the increasing and decreasing amounts of the refrigerant can be controlled by controlling the opening and closing of the third valve 63, and the control of the third valve 63 is more accurate than the control of the first valve 61 and the second valve 62 at the same time, the control method of the present application comprises: according to the state of the refrigeration system 1, the refrigeration system 1 is controlled to enter the adjustment state, wherein in the adjustment state, the third valve 63 is controlled to be opened, and the second valve 62 and the first valve 61 are controlled to be closed; in the first time period, the refrigeration system 1 is controlled to enter the increasing and decreasing adjustment state; and after the first time period ends, the refrigeration system 1 is controlled to return to the adjustment state. In this way, according to the state of the refrigeration system 1, when the state of the refrigeration system 1 indicates that the circulating amount of the refrigerant in the refrigeration system 1 needs to be adjusted at this time, the refrigeration system 1 is controlled to enter the adjustment state. Then, according to the state at this time, the refrigeration system 1 is controlled to enter the increasing and decreasing adjustment state in the first time period. Since in the increasing and decreasing adjustment state, one of the first valve 61 and the second valve 62 is controlled to be opened and the other is controlled to be closed, and the third valve 63 is controlled to be closed, so that the circulating amount of the refrigerant flowing in the compressor 4 and the heat exchanger 5 is increased or decreased, and thus the amount of the refrigerant in the refrigeration system 1 is increased or decreased according to the demand.

[0076] In some embodiments, the increase or decrease in the first time period does not meet the requirement of increasing or decreasing the amount of refrigerant circulating in the refrigeration system 1 at this time, and after the refrigeration system 1 returns to the adjustment state at the end of the first time period, the state of the refrigeration system 1 is obtained every interval preset adjustment time, and it is determined whether the amount of refrigerant circulating needs to be continuously increased or decreased. If the amount of refrigerant circulating needs to be continuously increased or decreased, the refrigeration system 1 is controlled to be in the increase or decrease adjustment state in the second time period. In this way, the refrigeration system 1 in the adjustment state first increases or decreases the refrigerant in the first time period, and then continues to judge whether the refrigerant needs to be increased or decreased according to the state of the interval adjustment time. In this way, the amount of refrigerant circulating in the system can be increased or decreased to a more appropriate amount, and the refrigeration effect of the refrigeration system 1 of the present application is good. In some embodiments, if it is necessary to enter the increase or decrease adjustment state for the second time, the time period during which one of the first valve 61 and the second valve 62 is opened and the other is closed can be slightly longer than the time period during which the third valve 63 is closed. In this way, it is ensured that the second increase or decrease of the amount of refrigerant circulating can be realized.

[0077] In some embodiments, when the refrigeration system 1 is in the adjustment state, the refrigeration system 1 can be controlled to exit the adjustment state and enter the working state according to the state of the refrigeration system 1, wherein in the working state, the third valve 63 is controlled to be closed, and the second valve 62 and the first valve 61 are controlled to be opened. In the working state, the amount of refrigerant circulating is constant, and the unit of the refrigeration system 1 operates normally.

[0078] In some embodiments, when the refrigeration system 1 enters the adjustment state and enters the increase or decrease adjustment state for the first time, in order to control the increase or decrease of the refrigerant, the refrigeration system 1 is in the increase or decrease adjustment state, one of the first valve 61 and the second valve 62 is opened and the other is closed, and the third valve 63 is controlled to be alternately opened and closed repeatedly for multiple times. Since the pressure in the cycle changes little, the increase or decrease amount and the increase or decrease speed of the amount of refrigerant circulating can be controlled according to the number of times the third valve 63 is closed and the opening and closing frequency. The length of time during which the third valve 63 is closed each time is the same, please refer to Figures 2-4 In the illustrated embodiment, when entering the adjustment state and entering the increase or decrease adjustment state for the first time, the length of time during which the third valve 63 is closed each time is 2S, and it is opened for 10S and closed once. In this way, the adjustment speed of the refrigerant is reasonable.

[0079] After the length of time during which the third valve 63 is closed each time is determined, the number of times the third valve 63 is closed can be determined to determine the increase or decrease amount of the amount of refrigerant circulating when entering the increase or decrease adjustment state for the first time. The more the number of times, the more the increase or decrease amount of the amount of refrigerant circulating. In Figure 2 and Figure 4 In the illustrated embodiment, when the refrigeration system 1 enters the adjustment state and enters the increase or decrease adjustment state for the first time, it is closed repeatedly for three times, and in Figure 3In the illustrated embodiment, when the refrigeration system 1 first enters the adjustment state and then the refrigerant adjustment state, it is repeatedly shut down six times. This number of times can be matched with the refrigerant system state. The number of times can be selected based on the state of the refrigeration system 1 after entering the adjustment state, or it can be preset. This allows for better control of refrigerant levels to achieve a better cooling effect.

[0080] The control method of the refrigeration system 1 in this application includes controlling the refrigeration system 1 to enter an increase / decrease adjustment state according to the state of the refrigeration system 1, and the conditions for entering the increase / decrease adjustment state can be selected according to the needs.

[0081] For example, to further increase the cooling capacity after the size of heat exchanger 5 reaches its limit, the refrigerant circulation rate can be increased, the condensing pressure can be raised, the heat exchange capacity of heat exchanger 5 can be increased, and the subcooling at the outlet of heat exchanger 5 can be increased, thereby increasing the cooling capacity. Furthermore, compared to the existing refrigeration system 1, the cooling speed is faster. Please refer to [reference needed]. Figure 2 ,exist Figure 2 In the illustrated embodiment, based on the state of the refrigeration system 1, controlling the refrigeration system 1 to enter an adjustment state includes: acquiring the return air temperature of the refrigeration system 1; if the return air temperature is greater than or equal to the set temperature, controlling the refrigeration system 1 to enter the adjustment state; and controlling the refrigeration system 1 to enter an increased adjustment state within a first time period. This increases the refrigerant circulation volume and accelerates the cooling speed. In some embodiments, the refrigeration system 1 may also enter the adjustment state when the return air temperature minus the set temperature is greater than a set threshold, such as 5°C. In the illustrated embodiment, the third valve 63 is controlled to close for 2 seconds every 10 seconds, repeated three times, thereby increasing the refrigerant circulation volume within the refrigeration system 1.

[0082] In the illustrated embodiment, when the return air temperature minus the set temperature is less than a set threshold, such as 1°C, the refrigeration system 1 exits the adjustment state and enters the working state. In the working state, the third valve 63 is closed, while the second valve 62 and the first valve 61 are opened. This configuration is reasonable, resulting in good cooling performance of the refrigeration system 1.

[0083] If, after initially increasing the refrigerant circulation rate in the adjustment phase, the subcooling at the outlet of heat exchanger 5 in refrigeration system 1 remains low, it is necessary to continue increasing the refrigerant circulation rate. Figure 2In the illustrated embodiment, the supercooling degree at the outlet of the heat exchanger 5 of the refrigeration system 1 is obtained every preset adjustment time length, and if the supercooling degree is less than the first threshold value, it is determined that the refrigerant circulation amount needs to be continuously increased, and the refrigeration system 1 is controlled to be in the increasing adjustment state within the second time length. In this way, the refrigerant amount of the present application is reasonable, and can be adjusted in real time according to the state of the refrigeration system 1, to ensure the refrigeration effect of the refrigeration system 1 of the present application. In some embodiments, the first threshold value is 5°C, the supercooling degree at the outlet of the heat exchanger 5 of the refrigeration system 1 is detected every preset adjustment time length, and if the supercooling degree is less than 5°C, the refrigeration system 1 is controlled to be in the increasing adjustment state within the second time length.

[0084] When the cold chain unit needs to be refrigerated at a very low ambient temperature (for example, -20°C). At this time, if the unit uses a brush fan, the condenser fan speed cannot be adjusted, and at this time the discharge pressure of the compressor 4 is often low, which does not meet the operating power of the compressor 4. At this time, by increasing the circulating refrigerant amount in the system, the condensing pressure is increased, so that the compressor 4 operates within the allowable range.

[0085] Please refer to Figure 3 , in Figure 3 In the illustrated embodiment, according to the state of the refrigeration system 1, the refrigeration system 1 is controlled to enter the adjustment state, including: obtaining the ambient temperature and the discharge pressure of the refrigeration system 1, and if the ambient temperature is greater than or equal to the set ambient temperature and the discharge pressure is less than or equal to the set discharge pressure, the refrigeration system 1 is controlled to enter the adjustment state. In this way, when the ambient temperature is low and the discharge pressure is small, the refrigerant circulation amount can be increased. In some embodiments, the set ambient temperature is 0°C, and the set discharge pressure is 7 bar. When the ambient temperature Ta is less than or equal to 0°C and the discharge pressure Pd is less than or equal to 7 bar, the refrigeration system 1 is controlled to enter the adjustment state. In some embodiments, in order to ensure the effect of increasing the condensing pressure, the adjustment state is maintained for at least five minutes. Within the first time length, the refrigeration system 1 is controlled to enter the increasing adjustment state. In the illustrated embodiment, the third valve 63 is controlled to be closed for 2S every 10S, and repeated three times, so that the refrigerant circulation amount in the refrigeration system 1 is increased.

[0086] In the illustrated embodiment, when the ambient temperature is greater than 0°C or the discharge pressure is greater than or equal to 20 bar, the refrigeration system 1 is controlled to exit the adjustment state and enter the working state, wherein in the working state, the third valve 63 is controlled to be closed, and the second valve 62 and the first valve 61 are controlled to be opened. In this way, the refrigeration system 1 has good refrigeration effect.

[0087] If the discharge pressure of the refrigeration system 1 is still low after the refrigerant circulation amount is increased for the first time, the refrigerant circulation amount still needs to be continuously increased. In Figure 3In the illustrated embodiment, the exhaust pressure of the refrigeration system 1 is obtained every preset adjustment duration, and if the exhaust pressure is less than or equal to the set exhaust pressure, the refrigerant circulation amount needs to be continuously increased, and the refrigeration system 1 is controlled to be in the increasing adjustment state within the second duration. In this way, the refrigerant increase amount of the present application is reasonable, and can be adjusted in real time according to the state of the refrigeration system 1, to ensure the refrigeration effect of the refrigeration system 1 of the present application. In some embodiments, the set exhaust pressure is 7 bar, and the supercooling degree at the outlet of the heat exchanger 5 of the refrigeration system 1 is detected every preset adjustment duration, and if the exhaust pressure of the refrigeration system 1 is less than or equal to 7 bar, the refrigeration system 1 is controlled to be in the increasing adjustment state within the second duration.

[0088] When the ambient temperature is high, the temperature in the box is also high, and at this time, the load is large, and there is a risk of high-voltage tripping. Figure 4 In the illustrated embodiment, the control method of the refrigeration system 1 of the present application can also be used to reduce the exhaust pressure by reducing the refrigerant circulation amount participating in the refrigeration system 1, so that the unit can withstand the initial harsh working conditions.

[0089] Please refer to Figure 4 , in Figure 4 In the illustrated embodiment, the ambient temperature and the return air temperature of the refrigeration system 1 are obtained, and if the ambient temperature is greater than or equal to the set ambient temperature and the return air temperature is greater than or equal to the set temperature, the refrigeration system 1 is controlled to enter the adjustment state. In this way, when the ambient temperature is high and the exhaust pressure is large, the refrigerant circulation amount can be reduced to relieve pressure, so that the unit can withstand the initial harsh working conditions. In some embodiments, the set ambient temperature is 52°C, and the set temperature is 20°C, and when the ambient temperature is greater than or equal to 52°C and the return air temperature is greater than or equal to 20°C, the refrigeration system 1 is controlled to enter the adjustment state, and within the first duration, the refrigeration system 1 is controlled to enter the reducing adjustment state.

[0090] In the illustrated embodiment, when the exhaust pressure is less than or equal to 26 bar or the compressor 4 exhaust temperature drop frequency temperature condition is triggered, the refrigeration system 1 is controlled to exit the adjustment state and enter the working state, wherein in the working state, the third valve 63 is controlled to be closed, and the second valve 62 and the first valve 61 are controlled to be opened. In this way, the setting is reasonable, and the refrigeration effect of the refrigeration system 1 is good.

[0091] In some embodiments, to ensure the stability of the refrigeration system 1 and to ensure the pressure relief effect, if it is necessary to reduce the refrigerant circulation amount in the system, the adjustment state is maintained for at least ten minutes, and in the adjustment state, the evaporative fan of the refrigeration system 1 is controlled to operate at the minimum speed, and the speed of the compressor 4 is controlled to be reduced or kept unchanged.

[0092] If the exhaust pressure of the refrigeration system 1 is still very high after the refrigerant circulation amount is increased for the first time to enter the increasing adjustment state, the refrigerant circulation amount still needs to be continuously reduced at this time. In Figure 4In the illustrated embodiment, the exhaust pressure of the refrigeration system 1 is obtained every preset adjustment duration, and if the exhaust pressure is greater than the set exhaust pressure, it is determined that the refrigerant circulation amount needs to be continuously reduced, and the refrigeration system 1 is controlled to be in a reducing adjustment state within a second duration. In this way, the refrigerant reduction amount of the present application is reasonable, and can be adjusted in real time according to the state of the refrigeration system 1, thereby ensuring the refrigeration effect of the refrigeration system 1 of the present application.

[0093] The control method of the refrigeration system 1 of the present application uses the refrigeration system 1 of the present application, includes a liquid storage tank, and can control one of the first valve 61 and the second valve 62 to be opened and the other to be closed, and control the third valve 63 to be closed, so as to increase or decrease the circulation amount of the refrigerant flowing in the compressor 4 and the heat exchanger 5. At the same time, the control method of the refrigeration system 1 of the present application includes controlling the increase or decrease of the refrigerant circulation amount according to the state of the refrigeration system 1, thereby enhancing the stability of the system and improving the satisfaction of the user.

[0094] The refrigeration system 1 of the present application also includes a controller for implementing the control method of the refrigeration system 1 described in any of the above embodiments. In some embodiments, the controller is used to control the refrigeration system 1 to enter an adjustment state, wherein in the adjustment state, the third valve 63 is controlled to be opened, and the second valve 62 and the first valve 61 are controlled to be closed;

[0095] When the refrigeration system 1 switches to the adjustment state, the controller is also used to control the refrigeration system 1 to enter an increasing and reducing adjustment state within a first duration, and after the first duration ends, the refrigeration system 1 returns to the adjustment state;

[0096] After the first duration ends and the refrigeration system 1 returns to the adjustment state, the controller is also used to obtain the state of the refrigeration system 1 every preset adjustment duration, determine whether to continue to increase or decrease the refrigerant circulation amount, and if the refrigerant circulation amount needs to be continuously increased or decreased, the refrigeration system 1 is controlled to be in an increasing and reducing adjustment state within a second duration.

[0097] In some embodiments, in the adjustment state of the refrigeration system 1, the controller is used to control the refrigeration system 1 to exit the adjustment state and enter a working state, wherein in the working state, the controller is used to control the third valve 63 to be closed, and the second valve 62 and the first valve 61 to be opened.

[0098] In some embodiments, the controller is used to control one of the first valve 61 and the second valve 62 to be opened and the other to be closed, and control the third valve 63 to be alternately opened and closed repeatedly for multiple times when the refrigeration system 1 is in the increasing and reducing adjustment state. The controller is used to control the increase or decrease amount and the increase or decrease speed of the refrigerant circulation amount according to the number of times of closing and the switching frequency of the third valve 63.

[0099] In Figure 2In the illustrated embodiment, the controller is configured to obtain the return air temperature of the refrigeration system 1, and if the return air temperature is greater than or equal to a set temperature, control the refrigeration system 1 to enter an adjustment state, and in a first time period, control the refrigeration system 1 to enter an increasing adjustment state. The controller is further configured to, after the first time period ends and the refrigeration system 1 returns to the adjustment state, obtain the supercooling degree of the outlet of the heat exchanger 5 every interval of a preset adjustment time, and if the supercooling degree is less than a first threshold, determine that the refrigerant circulation amount needs to be continuously increased, and in a second time period, control the refrigeration system 1 to be in the increasing adjustment state.

[0100] In Figure 3 In the illustrated embodiment, the controller is configured to obtain the return air temperature of the refrigeration system 1, and if the return air temperature is greater than or equal to a set temperature, control the refrigeration system 1 to enter an adjustment state, and in a first time period, control the refrigeration system 1 to enter an increasing adjustment state. The controller is further configured to, after the first time period ends and the refrigeration system 1 returns to the adjustment state, obtain the supercooling degree of the outlet of the heat exchanger 5 every interval of a preset adjustment time, and if the supercooling degree is less than a first threshold, determine that the refrigerant circulation amount needs to be continuously increased, and in a second time period, control the refrigeration system 1 to be in the increasing adjustment state.

[0101] In Figure 4 In the illustrated embodiment, the controller is configured to obtain the return air temperature of the refrigeration system 1, and if the return air temperature is greater than or equal to a set temperature, control the refrigeration system 1 to enter an adjustment state, and in a first time period, control the refrigeration system 1 to enter an increasing adjustment state. The controller is further configured to, after the first time period ends and the refrigeration system 1 returns to the adjustment state, obtain the supercooling degree of the outlet of the heat exchanger 5 every interval of a preset adjustment time, and if the supercooling degree is less than a first threshold, determine that the refrigerant circulation amount needs to be continuously increased, and in a second time period, control the refrigeration system 1 to be in the increasing adjustment state.

[0102] It should be understood that the present specification is not limited to the precise construction hereabove described and as shown in the drawings, and various modifications and changes can be made therein without departing from the scope thereof. The only scope of the specification is defined by the appended claims.

[0103] The specification is merely exemplary of the principles of the application. It is therefore contemplated that in the scope of the specification, modifications, equivalent replacements, improvements, etc. made to the specification, should be included in the scope of the specification.

Claims

1. A refrigeration system characterized by, The refrigeration system comprises a controller, a pipeline, a compressor, a liquid storage tank and a heat exchanger connected in series through the pipeline, the liquid storage tank comprises a liquid storage tank inlet and a liquid storage tank outlet, the pipeline comprises an inlet pipeline connected to the liquid storage tank inlet, an outlet pipeline connected to the liquid storage tank outlet and a control pipeline connecting the inlet pipeline and the outlet pipeline, the liquid storage tank is connected in series with the compressor and the heat exchanger through the inlet pipeline and the outlet pipeline; the inlet pipeline is provided with a first valve electrically connected to the controller, the outlet pipeline is provided with a second valve electrically connected to the controller, and the control pipeline is provided with a third valve electrically connected to the controller; The controller is used to control the refrigeration system to enter an increase / decrease adjustment state according to the state of the refrigeration system, wherein in the increase / decrease adjustment state, one of the first valve and the second valve is opened and the other is closed, and the third valve is closed, so that the circulating amount of refrigerant flowing in the compressor and the heat exchanger is increased or decreased.

2. The refrigeration system of claim 1 wherein, The increase / decrease adjustment state comprises an increase adjustment state and a decrease adjustment state; The controller is used to control the refrigeration system to enter the increase adjustment state or the decrease adjustment state according to the state of the refrigeration system, wherein in the increase adjustment state, the second valve is opened and the first valve and the third valve are closed, so that the circulating amount of refrigerant is increased; in the decrease adjustment state, the first valve is opened and the second valve and the third valve are closed, so that the circulating amount of refrigerant is decreased.

3. The refrigeration system of claim 2 wherein, The controller is also used to control the refrigeration system to enter an adjustment state; When the refrigeration system switches to the adjustment state, the controller is also used to control the refrigeration system to enter the increase / decrease adjustment state within a first time period; The controller is also used to determine whether to continue to increase / decrease the circulating amount of refrigerant every preset adjustment time period after the first time period ends, and if the circulating amount of refrigerant needs to be continued to be increased / decreased, control the refrigeration system to be in the increase / decrease adjustment state within a second time period.

4. The refrigeration system of claim 3 wherein, The controller is used to control one of the first valve and the second valve to be opened and the other to be closed, and control the third valve to be opened and closed alternately and repeatedly multiple times when the refrigeration system is in the increase / decrease adjustment state, and the controller is used to control the increase / decrease amount and the increase / decrease speed of the circulating amount of refrigerant according to the number of times of closing and the switching frequency of the third valve.

5. The refrigeration system of claim 3 wherein, The controller is used to obtain the return air temperature of the refrigeration system, and if the return air temperature is greater than or equal to a set temperature, control the refrigeration system to enter the adjustment state, control the refrigeration system to enter the increase adjustment state within a first time period, and the controller is also used to obtain the supercooling degree of the condenser outlet of the refrigeration system every preset adjustment time period after the first time period ends and the refrigeration system returns to the adjustment state, and if the supercooling degree is less than a first threshold, it is determined that the circulating amount of refrigerant needs to be continued to be increased, and the refrigeration system is controlled to be in the increase adjustment state within a second time period.

6. The refrigeration system of claim 2 wherein, The controller is configured to acquire an ambient temperature and a discharge pressure of the refrigeration system, and control the refrigeration system to enter an adjustment state if the ambient temperature is less than a set ambient temperature and the discharge pressure is less than or equal to a set discharge pressure, and control the refrigeration system to enter an increasing adjustment state in a first time period.

7. The refrigeration system of claim 2 wherein, The controller is configured to acquire an ambient temperature and a return air temperature of the refrigeration system, and control the refrigeration system to enter an adjustment state if the ambient temperature is greater than or equal to a set ambient temperature and the return air temperature is greater than or equal to a set temperature, and control the refrigeration system to enter a decreasing adjustment state in a first time period.

8. The refrigeration system of claim 7 wherein, The controller is further configured to control the evaporative fan of the refrigeration system to operate at a minimum speed in the adjustment state; and / or The controller is further configured to control the speed of the compressor to decrease or remain unchanged in the adjustment state.

9. The refrigeration system of claim 1 wherein, The end of the outlet pipe connected to the liquid storage tank is close to the bottom of the liquid storage tank relative to the top of the liquid storage tank; and / or The end of the inlet pipe connected to the liquid storage tank is close to the top of the liquid storage tank relative to the bottom of the liquid storage tank.

10. A control method of a refrigeration system, characterized by, The refrigeration system comprises a controller, a pipe, and a compressor, a liquid storage tank and a heat exchanger connected in series through the pipe, the liquid storage tank comprises a liquid storage tank inlet and a liquid storage tank outlet, the pipe comprises an inlet pipe connected to the liquid storage tank inlet, an outlet pipe connected to the liquid storage tank outlet, and a control pipe connecting the inlet pipe and the outlet pipe, the liquid storage tank is connected in series with the compressor and the heat exchanger through the inlet pipe and the outlet pipe; the inlet pipe is provided with a first valve electrically connected to the controller, the outlet pipe is provided with a second valve electrically connected to the controller, and the control pipe is provided with a third valve electrically connected to the controller, and the control method comprises: According to the state of the refrigeration system, the refrigeration system is controlled to enter an increasing and decreasing adjustment state, wherein in the increasing and decreasing adjustment state, one of the first valve and the second valve is opened and the other is closed, and the third valve is closed at the same time, so that the circulating amount of refrigerant flowing in the compressor and the heat exchanger is increased or decreased.

11. The control method of a refrigeration system according to claim 10, characterized by, The increasing and decreasing adjustment state comprises an increasing adjustment state and a decreasing adjustment state; The controller is configured to acquire an ambient temperature and a discharge pressure of the refrigeration system, and control the refrigeration system to enter an adjustment state if the ambient temperature is less than a set ambient temperature and the discharge pressure is less than or equal to a set discharge pressure, and control the refrigeration system to enter an increasing adjustment state in a first time period. The controller is configured to acquire an ambient temperature and a return air temperature of the refrigeration system, and control the refrigeration system to enter an adjustment state if the ambient temperature is greater than or equal to a set ambient temperature and the return air temperature is greater than or equal to a set temperature, and control the refrigeration system to enter a decreasing adjustment state in a first time period. The controller is further configured to control the evaporative fan of the refrigeration system to operate at a minimum speed in the adjustment state; and / or The controller is further configured to control the speed of the compressor to decrease or remain unchanged in the adjustment state. The end of the outlet pipe connected to the liquid storage tank is close to the bottom of the liquid storage tank relative to the top of the liquid storage tank; and / or The end of the inlet pipe connected to the liquid storage tank is close to the top of the liquid storage tank relative to the bottom of the liquid storage tank. The refrigeration system comprises a controller, a pipe, and a compressor, a liquid storage tank and a heat exchanger connected in series through the pipe, the liquid storage tank comprises a liquid storage tank inlet and a liquid storage tank outlet, the pipe comprises an inlet pipe connected to the liquid storage tank inlet, an outlet pipe connected to the liquid storage tank outlet, and a control pipe connecting the inlet pipe and the outlet pipe, the liquid storage tank is connected in series with the compressor and the heat exchanger through the inlet pipe and the outlet pipe; the inlet pipe is provided with a first valve electrically connected to the controller, the outlet pipe is provided with a second valve electrically connected to the controller, and the control pipe is provided with a third valve electrically connected to the controller, and the control method comprises: According to the state of the refrigeration system, the refrigeration system is controlled to enter an increasing and decreasing adjustment state, wherein in the increasing and decreasing adjustment state, one of the first valve and the second valve is opened and the other is closed, and the third valve is closed at the same time, so that the circulating amount of refrigerant flowing in the compressor and the heat exchanger is increased or decreased. The increasing and decreasing adjustment state comprises an increasing adjustment state and a decreasing adjustment state; The controller is configured to acquire an ambient temperature and a discharge pressure of the refrigeration system, and control the refrigeration system to enter an adjustment state if the ambient temperature is less than a set ambient temperature and the discharge pressure is less than or equal to a set discharge pressure, and control the refrigeration system to enter an increasing adjustment state in a first time period. controlling the refrigeration system to enter an increasing adjustment state according to a state of the refrigeration system, wherein in the increasing adjustment state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so that the refrigerant circulation amount is increased; controlling the refrigeration system to enter a decreasing adjustment state according to a state of the refrigeration system, wherein in the decreasing adjustment state, the first valve is controlled to be opened, and the second valve and the third valve are controlled to be closed, so that the refrigerant circulation amount is decreased.

12. The control method of a refrigeration system according to claim 11, characterized by, The controlling the refrigeration system to enter the increasing and decreasing adjustment state according to the state of the refrigeration system comprises: controlling the refrigeration system to enter an adjustment state according to a state of the refrigeration system; controlling the refrigeration system to enter the increasing and decreasing adjustment state within a first time length; after the first time length ends, acquiring the state of the refrigeration system every interval of a preset adjustment time length, and determining whether the refrigerant circulation amount needs to be continuously increased or decreased, if the refrigerant circulation amount needs to be continuously increased or decreased, controlling the refrigeration system to be in the increasing and decreasing adjustment state within a second time length.

13. The control method of a refrigeration system according to claim 12, characterized by, The control method further comprises: when the refrigeration system is in the increasing and decreasing adjustment state, one of the first valve and the second valve is controlled to be opened and the other is controlled to be closed, and the third valve is controlled to be alternately opened and closed repeatedly for multiple times, wherein the increasing and decreasing amount and the increasing and decreasing speed of the refrigerant circulation amount are controlled according to the number of times of closing and the switching frequency of the third valve.

14. The control method of a refrigeration system according to claim 12, characterized by, The increasing and decreasing adjustment state comprises an increasing adjustment state, wherein in the increasing adjustment state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so that the refrigerant circulation amount is increased; The controlling the refrigeration system to enter the adjustment state according to the state of the refrigeration system comprises: acquiring a return air temperature of the refrigeration system, and if the return air temperature is greater than or equal to a set temperature, controlling the refrigeration system to enter the adjustment state. The controlling the refrigeration system to enter the increasing and decreasing adjustment state within the first time length comprises: controlling the refrigeration system to enter the increasing adjustment state within the first time length; The acquiring the state of the refrigeration system every interval of the preset adjustment time length and determining whether the refrigerant circulation amount needs to be continuously increased or decreased, if the refrigerant circulation amount needs to be continuously increased or decreased, controlling the refrigeration system to be in the increasing and decreasing adjustment state within the second time length, comprises: acquiring a supercooling degree of an outlet of a condenser of the refrigeration system every interval of the preset adjustment time length, and if the supercooling degree is less than a first threshold, determining that the refrigerant circulation amount needs to be continuously increased, and controlling the refrigeration system to be in the increasing adjustment state within the second time length.

15. The control method of a refrigeration system according to claim 12, characterized by, The increasing and decreasing adjustment state comprises an increasing adjustment state, wherein in the increasing adjustment state, the second valve is controlled to be opened, and the first valve and the third valve are controlled to be closed, so that the refrigerant circulation amount is increased; The step of controlling the refrigeration system to enter an adjustment state based on the state of the refrigeration system includes: acquiring the ambient temperature and the exhaust pressure of the refrigeration system; if the ambient temperature is lower than a set ambient temperature and the exhaust pressure is less than or equal to a set exhaust pressure, controlling the refrigeration system to enter an adjustment state. During the first time period, controlling the refrigeration system to enter an increase / decrease adjustment state includes: Within the first duration, the refrigeration system is controlled to enter an increased adjustment state; The system obtains the status of the refrigeration system at each preset adjustment time interval, determines whether the refrigerant circulation volume needs to be increased or decreased, and if it is determined that the refrigerant circulation volume needs to be increased or decreased, controls the refrigeration system to be in the increase / decrease adjustment state for a second time period, including: At each preset adjustment time interval, the exhaust pressure of the refrigeration system is obtained. If the exhaust pressure is less than or equal to the set exhaust pressure, the refrigerant circulation volume needs to be increased. The refrigeration system is controlled to be in the increased adjustment state within the second time interval.

16. The control method of a refrigeration system according to claim 12, characterized by, The increase / decrease adjustment state includes a decrease adjustment state; wherein, in the decrease adjustment state, the first valve is controlled to open, and the second valve and the third valve are controlled to close, so as to reduce the refrigerant circulation amount; The step of controlling the refrigeration system to enter an adjustment state based on the state of the refrigeration system includes: acquiring the ambient temperature and the return air temperature of the refrigeration system; if the ambient temperature is greater than or equal to a set ambient temperature and the return air temperature is greater than or equal to a set temperature, controlling the refrigeration system to enter an adjustment state. During the first time period, controlling the refrigeration system to enter an increase / decrease adjustment state includes: Within the first duration, the refrigeration system is controlled to enter a reduction adjustment state; The system obtains the status of the refrigeration system at each preset adjustment time interval, determines whether the refrigerant circulation volume needs to be increased or decreased, and if it needs to be increased or decreased, controls the refrigeration system to be in the increase / decrease adjustment state for a second time interval, including: At each preset adjustment time interval, the exhaust pressure of the refrigeration system is obtained. If the exhaust pressure is greater than the set exhaust pressure, it is determined that the refrigerant circulation volume needs to be further reduced, and the refrigeration system is controlled to be in the reduction adjustment state for a second time period.

17. The control method of a refrigeration system according to claim 16, characterized by, The control method further includes: During the adjustment state, the evaporator fan of the refrigeration system is controlled to operate at the minimum speed; and / or the speed of the compressor is controlled to decrease or remain unchanged.

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