Refrigeration system, method of controlling the same and multi-stage refrigeration system

Abstract

The application discloses a refrigeration system, a control method thereof and a multi-stage refrigeration system. The refrigeration system comprises a main refrigeration circuit formed by a compressor, a condenser, a solenoid valve, a first throttling device and a first evaporator; a bypass refrigeration circuit formed by the compressor, a quick-opening valve, a second throttling device and a second evaporator; and a controller connected with the quick-opening valve and used for controlling the conduction, the shutdown or the switching ratio of the quick-opening valve according to a temperature parameter and a heating power parameter of a heating device. Further, the conduction, the shutdown or the switching ratio of the quick-opening valve is controlled according to the temperature parameter and the heating power parameter of the heating device. When the temperature parameter and the heating power parameter satisfy certain conditions, different flow rates of high-temperature and high-pressure gas refrigerants are delivered to the evaporator through the conduction and the switching ratio of the quick-opening valve, so that the power output of the heating device is reduced, and the energy-saving effect of reducing energy consumption is achieved.

Description

Technical Field

[0001] This invention relates to the field of refrigeration system technology, and in particular to a refrigeration system and its control method and a multi-stage refrigeration system. Background Technology

[0002] In environmental testing, high and low temperature change tests with temperature change rate are generally conducted using high and low temperature test chambers. The temperature values ​​of high and low temperatures, the cooling and heating rates, and the number of cycles are used to simulate the temperature changes of the surrounding environment in order to test the performance of the test samples.

[0003] For environmental testing equipment used in temperature and humidity environments, when the equipment operates at a constant temperature, such as -60℃, the heating system will also run synchronously to maintain the -60℃ constant temperature and keep fluctuations within the allowable range, which will increase energy consumption. Summary of the Invention

[0004] This invention provides a refrigeration system and its control method, as well as a multi-stage refrigeration system, to solve the problem of high energy consumption of the heating system in related solutions.

[0005] To achieve the above objectives, a first aspect of the present invention provides a refrigeration system, comprising: a heating device and a controller;

[0006] The main refrigeration circuit is formed by the compressor, condenser, solenoid valve, first throttling device and first evaporator;

[0007] The compressor, quick-opening valve, second throttling device, and second evaporator form a bypass refrigeration circuit;

[0008] The controller is connected to the quick-opening valve and the heating device respectively, and is used to control the opening, closing or switching ratio of the quick-opening valve according to the temperature parameter and the heating power parameter of the heating device, wherein the first evaporator and the second evaporator are the same evaporator or different evaporators.

[0009] According to one embodiment of the present invention, the compressor includes a first exhaust port, a second exhaust port, and a return port. The first exhaust port is connected to the inlet of the condenser, the outlet of the condenser is connected to the inlet of the solenoid valve, the outlet of the solenoid valve is connected to the inlet of the first throttling device, the outlet of the first throttling device is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the return port, forming the main refrigeration circuit.

[0010] The second exhaust port is connected to the inlet of the quick-opening valve, the outlet of the quick-opening valve is connected to the inlet of the second throttling device, the outlet of the second throttling device is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the return port, forming the bypass refrigeration circuit.

[0011] According to one embodiment of the present invention, both the first throttling device and the second throttling device include one of an electronic expansion valve, a thermal expansion valve, or a capillary tube.

[0012] To achieve the above objectives, a second aspect of the present invention provides a multi-stage refrigeration system, including the refrigeration system described in any embodiment of the present invention.

[0013] To achieve the above objectives, a third aspect of the present invention provides a control method for a refrigeration system, implemented based on the refrigeration system described in any embodiment of the present invention. The control method includes the following steps:

[0014] Obtain the temperature parameters and the heating power parameters of the heating device;

[0015] The on / off or switching ratio of the quick-opening valve is controlled according to the temperature parameter and the heating power parameter.

[0016] According to one embodiment of the present invention, obtaining the temperature parameter and the heating power parameter of the heating device includes:

[0017] Obtain the target temperature;

[0018] Obtain the measured temperature;

[0019] Obtain the actual power output value of the heating device;

[0020] Obtain the deviation between the measured temperature and the target temperature;

[0021] The control of the on / off or switching ratio of the quick-opening valve based on the temperature parameter and the heating power parameter includes:

[0022] When the target temperature is less than or equal to the preset target temperature, the deviation value is less than or equal to the preset deviation value, the actual power output value is greater than or equal to the preset maximum power output value, and the heating device operates at the actual power output value that is greater than or equal to the preset maximum power output value for a duration greater than or equal to the preset duration, the quick-opening valve is controlled to open.

[0023] According to one embodiment of the present invention, controlling the on / off or switching ratio of the quick-opening valve based on the temperature parameter and the heating power parameter includes:

[0024] When the target temperature is greater than the preset target temperature, or the deviation value is greater than the preset deviation value, or the actual power output value is less than the preset minimum power output value, or the actual power output value is greater than or equal to the preset maximum power output value, but the heating device operates at the actual power output value which is greater than or equal to the preset maximum power output value, and the operating duration is less than the preset duration, the quick-opening valve is controlled to close.

[0025] According to one embodiment of the present invention, controlling the on / off or switching ratio of the quick-opening valve based on the temperature parameter and the heating power parameter includes:

[0026] After controlling the quick-opening valve to open.

[0027] When the target temperature is less than or equal to the preset target temperature, and the deviation value is less than or equal to the preset deviation value, and the actual power output value is greater than the preset minimum power output value and less than or equal to the preset maximum power output value, the switching ratio of the quick-opening valve is adjusted; and when the actual power output value is less than the preset minimum power output value, or when the target temperature is greater than the preset target temperature, or when the deviation value is greater than the preset deviation value, the quick-opening valve is controlled to close.

[0028] According to embodiments of the present invention, a refrigeration system and its control method, and a multi-stage refrigeration system, wherein the refrigeration system includes: a heating device and a controller; a main refrigeration circuit formed by a compressor, a condenser, a solenoid valve, a first throttling device, and a first evaporator; and a bypass refrigeration circuit formed by the compressor, a quick-opening valve, a second throttling device, and a second evaporator; the controller is connected to the quick-opening valve and the heating device respectively, and is used to control the on / off or switching ratio of the quick-opening valve according to the temperature parameters and the heating power parameters of the heating device, wherein the first evaporator and the second evaporator are the same evaporator or different evaporators. Furthermore, by controlling the on / off or switching ratio of the quick-opening valve according to the temperature parameters and the heating power parameters of the heating device, when the temperature parameters and heating power parameters meet certain conditions, different flow rates of high-temperature, high-pressure gaseous refrigerant are supplied to the evaporator through the on / off state of the quick-opening valve and the adjustment of the switching ratio, thereby reducing the power output of the heating device and achieving an energy-saving effect by reducing energy consumption.

[0029] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the refrigeration system proposed in an embodiment of the present invention;

[0032] Figure 2 This is a flowchart of the control method for the refrigeration system proposed in an embodiment of the present invention;

[0033] Figure 3 This is a flowchart of a control method for a refrigeration system according to an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the multi-stage refrigeration system proposed in an embodiment of the present invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] Figure 1 This is a schematic diagram of the refrigeration system proposed in an embodiment of the present invention. Figure 1As shown, the refrigeration system 100 includes: a compressor 101, a condenser 102, a solenoid valve 103, a first throttling device 104, a quick-opening valve 105, a second throttling device 106, an evaporator 107, a heating device 108, and a controller 109.

[0038] The compressor 101, condenser 102, solenoid valve 103, first throttling device 104 and first evaporator form the main refrigeration circuit; the compressor 101, quick-opening valve 105, second throttling device 106 and second evaporator form the bypass refrigeration circuit.

[0039] The controller 107 is connected to the quick-opening valve 105 and is used to control the opening, closing or switching ratio of the quick-opening valve according to the temperature parameters of the refrigeration system 100 and the heating power parameters of the heating device.

[0040] The first evaporator and the second evaporator can be the same evaporator 107 or different evaporators. Both the first evaporator and the second evaporator can be cascaded evaporators.

[0041] Continue to refer to Figure 1 The compressor 101 includes a first exhaust port, a second exhaust port, and a return port. The first exhaust port is connected to the inlet of the condenser 102, the outlet of the condenser 102 is connected to the inlet of the solenoid valve 103, the outlet of the solenoid valve 103 is connected to the inlet of the first throttling device 104, the outlet of the first throttling device 104 is connected to the inlet of the evaporator 107, and the outlet of the evaporator 107 is connected to the return port, forming the main refrigeration circuit.

[0042] The second exhaust port is connected to the inlet of the quick-opening valve 105, the outlet of the quick-opening valve 105 is connected to the inlet of the second throttling device 106, the outlet of the second throttling device 106 is connected to the inlet of the evaporator 107, and the outlet of the evaporator 107 is connected to the return gas port, forming a bypass refrigeration circuit.

[0043] Both the first throttling device 104 and the second throttling device 106 include one of an electronic expansion valve, a thermal expansion valve, or a capillary tube. Preferably, the first throttling device 104 is an electronic expansion valve, and the second throttling device 106 is a capillary tube.

[0044] It should be noted that the main refrigeration circuit works as follows: The compressor 101 outputs high-temperature, high-pressure gaseous refrigerant from its first discharge port to the condenser 102. The condenser 102 condenses the high-temperature, high-pressure gaseous refrigerant into a medium-temperature, high-pressure liquid refrigerant. This liquid refrigerant is then converted into a low-temperature, low-pressure gas-liquid two-phase system via the solenoid valve 103 and the first throttling device 104, and enters the evaporator 107 for evaporation, converting back into a low-temperature, low-pressure gaseous refrigerant. The liquid then returns to the compressor 101's return port to begin a new refrigeration cycle. During this process, when certain conditions are met (i.e., temperature and heating power parameters meet certain conditions), the controller 109 activates the bypass refrigeration circuit, providing high-temperature, high-pressure gaseous refrigerant to the evaporator 107. This reduces the power output of the heating device 108, thereby achieving energy savings.

[0045] In other words, the high-temperature and high-pressure gaseous refrigerant discharged from the second exhaust port of compressor 101 enters the quick-opening valve 105 and the second throttling device 106, and then enters the evaporator 107 to evaporate, forming a low-temperature and low-pressure gaseous refrigerant, which returns to the return port of compressor 101 to start a new round of refrigeration cycle.

[0046] The following details the control method of the refrigeration system, namely, the control of the bypass refrigeration circuit by the controller 109.

[0047] Specifically, this control method is implemented based on the refrigeration system 100 of any embodiment of the present invention. For example... Figure 2 As shown, the control method includes the following steps:

[0048] S101, Obtain temperature parameters and heating power parameters of the heating device;

[0049] S102 controls the on / off or switching ratio of the quick-opening valve based on temperature and heating power parameters.

[0050] Among them, S101 acquires temperature parameters and heating power parameters of the heating device, including:

[0051] Obtain the target temperature; where the target temperature is the temperature set by the user.

[0052] The measured temperature can be obtained through the temperature sensor in the system.

[0053] Obtain the actual power output value of the heating device; the actual power output value can be obtained by monitoring the current and voltage of the heating device.

[0054] Obtain the deviation between the measured temperature and the target temperature; the deviation can be obtained through an algorithm pre-set in the controller.

[0055] S102 controls the on / off or switching ratio of the quick-opening valve based on temperature and heating power parameters, including:

[0056] When the target temperature is less than or equal to the preset target temperature, and the deviation value is less than or equal to the preset deviation value, and the actual power output value is greater than or equal to the preset maximum power output value, and the heating device operates with an actual power output value greater than or equal to the preset maximum power output value, and the operating duration is greater than or equal to the preset duration, the control quick-opening valve is turned on.

[0057] In other words, when the user-set temperature is less than or equal to a preset target temperature (pre-stored in the controller; this preset target temperature can be the cooling temperature range of the entire refrigeration system), that is, when the user-set temperature is within the cooling temperature range of the refrigeration system, the actual temperature of the refrigeration system can be detected in real time. This allows for the determination of the deviation between the actual temperature and the user-set temperature. When the deviation is less than the preset deviation value, it indicates that the actual temperature is close to the user-set temperature. During this process, the actual output power of the heating device can be acquired in real time. When the actual power output value is greater than or equal to the preset maximum power output value, the duration for which the heating device operates at the current actual power output value is obtained. When the operating duration meets the preset duration, and the actual temperature fluctuates within a certain range above and below the user-set temperature, the quick-opening valve can be activated. High-temperature, high-pressure refrigerant is then introduced into the evaporator to reduce the energy consumption of the heating device.

[0058] The initial opening degree of the quick-opening valve can be preset in the controller. In addition, the opening ratio of the quick-opening valve can be adjusted after the quick-opening valve is turned on.

[0059] According to one embodiment of the present invention, controlling the on / off or switching ratio of the quick-opening valve based on temperature parameters and heating power parameters includes:

[0060] When the target temperature is greater than the preset target temperature, or the deviation value is greater than the preset deviation value, or the actual power output value is less than the preset minimum power output value, or the actual power output value is greater than or equal to the preset maximum power output value, but the heating device operates with an actual power output value greater than or equal to the preset maximum power output value, and the operating duration is less than the preset duration, the quick-opening valve is controlled to close.

[0061] In other words, if the user-set temperature is outside the cooling system's temperature range, the cooling system will not start. If the user-set temperature is within the cooling system's temperature range, but the actual measured temperature deviates significantly from the user-set temperature, the cooling system needs to operate at high power to cool down. If the actual power output of the heating device is less than the preset minimum power output, or greater than the preset maximum power output, but the continuous operating time is less than the preset duration, the bypass cooling circuit will remain shut off under these conditions.

[0062] According to one embodiment of the present invention, controlling the on / off or switching ratio of the quick-opening valve based on temperature parameters and heating power parameters includes:

[0063] After the quick-opening valve is activated...

[0064] When the target temperature is less than or equal to the preset target temperature, and the deviation value is less than or equal to the preset deviation value, and the actual power output value is greater than the preset minimum power output value and less than or equal to the preset maximum power output value, the switching ratio of the quick-opening valve is adjusted; and when the actual power output value is less than the preset minimum power output value, or when the target temperature is greater than the preset target temperature, or when the deviation value is greater than the preset deviation value, the quick-opening valve is controlled to close.

[0065] In other words, after the bypass refrigeration circuit is opened under the given conditions, the actual power output of the heating device is monitored in real time. When the actual power output is between the preset minimum and maximum power output values, the on / off ratio of the quick-opening valve can be adjusted, for example, the on / off ratio per unit time can be 3 / 2, to dynamically adjust the refrigerant flow supplied to the evaporator. When the actual power output is less than the preset minimum power output value, the quick-opening valve is controlled to close. This avoids frequent opening and closing of the quick-opening valve, which could cause system instability.

[0066] More specifically, the current measured temperature can be obtained through an installed temperature sensor and can be represented by TPV, in °C. The actual power output value of the heating device can be obtained by monitoring the voltage and current of the heating device. It can be represented by TQ_heater_output, which is the actual power output of the heating system, in %.

[0067] In addition, the controller can also pre-store the following: set / target cooling temperature, TSV, unit: °C; initial low temperature control entry value for set temperature TSV_low (i.e., target temperature), unit: °C; initial low temperature control entry deviation value for set temperature T_low_diff, unit: °C; allowable temperature constant fluctuation value T_constant_diff (i.e., preset deviation value), unit: °C; actual power output control entry value for the heating system TQ_heater_output_diff_max (i.e., preset maximum power output), unit: %; actual power output control entry value for the heating system TQ_heater_output_diff_min (i.e., preset minimum power output), unit: %; actual power output control entry time for the heating system t_heater_output_diff_max (i.e., duration), unit: s; actual power output control entry duration for the heating system t_duration (preset duration), unit: s.

[0068] Furthermore, the conditions for controlling whether the quick-opening valve is conductive are as follows:

[0069] ①TSV≤TSV_low+T_low_diff;

[0070] ②|TSV-TPV|≤T_constant_diff;

[0071] ③TQ_heater_output≥TQ_heater_output_diff_max;

[0072] ④t_heater_output_diff_max≥t_duration.

[0073] Entry condition: When all the above conditions ①, ②, ③ and ④ are satisfied at the same time, the flow rate of high-temperature exhaust gas from the compressor can be controlled by the quick-opening valve, which passes through the quick-opening valve and the second throttling device, then enters the evaporator, and performs forced convection heat exchange through the fan, so as to reduce the output of the heating device and achieve the energy-saving effect.

[0074] Exit condition: When any one of the above conditions ①, ②, ③ and ④ is not satisfied, where condition ③ is not satisfied but TQ_heater_output<TQ_heater_output_diff_min is satisfied, the control over the quick-opening valve is exited.

[0075] In terms of a specific embodiment, as shown Figure 3 in the figure, the control method includes:

[0076] S201: Acquire the target temperature;

[0077] S202: Determine whether the target temperature is within the preset target temperature range. If yes, execute step S203; if no, return to step S201;

[0078] S203: Acquire the measured temperature of the refrigeration system in real time, and the deviation value between the measured temperature and the target temperature;

[0079] S204: Determine whether the deviation value is less than or equal to the preset deviation value. If yes, execute step S205; if no, return to step S203;

[0080] S205: Acquire the actual power output value of the heating device in real time;

[0081] S206: Determine whether the actual power output value is greater than or equal to the maximum actual power output value. If yes, execute step S207; if no, return to step S205;

[0082] S207: Acquire the duration during which the actual power output value of the heating device is greater than or equal to the maximum actual power output value.

[0083] S208, determine whether the duration is greater than or equal to the preset duration. If yes, proceed to step S209; otherwise, return to step S207.

[0084] S209, control the quick-opening valve to open; execute step S205;

[0085] S210, determine whether the actual power output value is less than the minimum actual power output value. If yes, proceed to step S211; otherwise, proceed to step S212.

[0086] S211, control the quick-opening valve to close; return to step S201;

[0087] S212, adjust the on / off ratio of the quick-opening valve, and return to step S210.

[0088] Figure 4 This is a schematic diagram of the structure of the multi-stage refrigeration system proposed in an embodiment of the present invention. Figure 4 As shown, this multi-stage refrigeration system is the refrigeration system 100 of any embodiment of the present invention.

[0089] This multi-stage refrigeration system includes a first-stage refrigeration system and a second-stage refrigeration system. In other embodiments, it may also include a third-stage or fourth-stage refrigeration system. The control logic for the bypass refrigeration circuit in the multi-stage refrigeration system can be referred to the control method in this embodiment, and will not be repeated here.

[0090] like Figure 4 As shown, the multi-stage refrigeration system 200 includes a high-temperature stage refrigeration system and a low-temperature stage refrigeration system. The high-temperature stage refrigeration system includes a first main refrigeration circuit, a second main refrigeration circuit, and a bypass refrigeration circuit. The low-temperature stage refrigeration system includes a low-temperature main refrigeration circuit.

[0091] The connection relationship between the primary refrigeration circuit and the bypass refrigeration circuit is as follows: Figure 1 As shown in the diagram. In the second main refrigeration circuit, the high-temperature, high-pressure gas discharged from the compressor 101 passes through the condenser 102 to form a low-temperature, high-pressure liquid, which then enters the second solenoid valve 113 and the third throttling device 114 to form a low-temperature, low-pressure liquid. This liquid then passes through the condenser-evaporator 112 to form a low-temperature, low-pressure gas, which returns to the compressor 101. In the low-temperature main refrigeration circuit, the high-temperature, high-pressure gas discharged from the second compressor 111 passes through the condenser 102 to form a low-temperature, high-pressure liquid, which then enters the fourth throttling device 115 to form a low-temperature, low-pressure liquid. This liquid then passes through the evaporator 107 to form a low-temperature, low-pressure gas, which returns to the second compressor 111.

[0092] The evaporator 107 also includes a dehumidification system 110. In the aforementioned refrigeration system, different refrigeration circuits can be activated at different target refrigeration temperatures. Furthermore, when the heating power parameters and temperature parameters meet the aforementioned conditions, the bypass refrigeration circuit can be controlled to open or close. The above example only illustrates a cascade system; multi-stage refrigeration systems can be controlled with reference to the above example. This saves energy consumption of the heating device.

[0093] In summary, the refrigeration system and its control method, as well as the multi-stage refrigeration system proposed in the embodiments of the present invention, wherein the refrigeration system includes: a compressor, a condenser, a solenoid valve, a first throttling device, a quick-opening valve, a second throttling device, an evaporator, a heating device, and a controller; the compressor, condenser, solenoid valve, first throttling device, and evaporator form a main refrigeration circuit; the compressor, quick-opening valve, second throttling device, and evaporator form a bypass refrigeration circuit; the controller is connected to the quick-opening valve and is used to control the on / off state or switching ratio of the quick-opening valve according to temperature parameters and heating power parameters of the heating device. Furthermore, by controlling the on / off state or switching ratio of the quick-opening valve according to temperature parameters and heating power parameters of the heating device, when the temperature parameters and heating power parameters meet certain conditions, different flow rates of high-temperature, high-pressure gaseous refrigerant are supplied to the evaporator through the on / off state and the regulation of the switching ratio of the quick-opening valve, thereby reducing the power output of the heating device and achieving energy-saving effects by reducing energy consumption.

[0094] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0095] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A refrigeration system, characterized in that, include: Heating device and controller; The main refrigeration circuit is formed by the compressor, condenser, solenoid valve, first throttling device and first evaporator; The compressor, quick-opening valve, second throttling device, and second evaporator form a bypass refrigeration circuit; The controller is connected to the quick-opening valve and the heating device respectively, and is used to control the opening, closing or switching ratio of the quick-opening valve according to the temperature parameter and the heating power parameter of the heating device. The temperature parameter is the target temperature and the measured temperature of the refrigeration system. The first evaporator and the second evaporator are the same evaporator or different evaporators. When all four conditions are met simultaneously—the target temperature is less than or equal to the preset target temperature, the deviation between the target temperature and the measured temperature is less than or equal to the preset deviation value, the actual power output value of the heating device is greater than or equal to the preset maximum power output value, and the heating device operates at an actual power output value greater than or equal to the preset maximum power output value for a duration greater than or equal to the preset duration—the quick-opening valve is controlled to open. After the quick-opening valve is turned on, when the target temperature is less than or equal to the preset target temperature, the deviation value is less than or equal to the preset deviation value, and the actual power output value is greater than the preset minimum power output value and less than or equal to the preset maximum power output value, the switching ratio of the quick-opening valve is adjusted. When the target temperature is greater than the preset target temperature, or the deviation value is greater than the preset deviation value, or the actual power output value is less than the preset minimum power output value, or the actual power output value is greater than or equal to the preset maximum power output value, but the heating device operates with an actual power output value greater than or equal to the preset maximum power output value and the operating duration is less than the preset duration, the quick-opening valve is controlled to close.

2. The refrigeration system according to claim 1, characterized in that, The compressor includes a first exhaust port, a second exhaust port, and a return port. The first exhaust port is connected to the inlet of the condenser, the outlet of the condenser is connected to the inlet of the solenoid valve, the outlet of the solenoid valve is connected to the inlet of the first throttling device, the outlet of the first throttling device is connected to the inlet of the first evaporator, and the outlet of the first evaporator is connected to the return port, forming the main refrigeration circuit. The second exhaust port is connected to the inlet of the quick-opening valve, the outlet of the quick-opening valve is connected to the inlet of the second throttling device, the outlet of the second throttling device is connected to the inlet of the second evaporator, and the outlet of the second evaporator is connected to the return port, forming the bypass refrigeration circuit.

3. The refrigeration system according to claim 1 or 2, characterized in that, Both the first throttling device and the second throttling device include one of the following: an electronic expansion valve, a thermal expansion valve, or a capillary tube.

4. A multi-stage refrigeration system, characterized in that, Includes the refrigeration system as described in any one of claims 1-3.

5. A control method for a refrigeration system, characterized in that, Based on the refrigeration system as described in any one of claims 1-3, the control method includes the following steps: Obtain the temperature parameters and the heating power parameters of the heating device; The on / off or switching ratio of the quick-opening valve is controlled according to the temperature parameter and the heating power parameter.

6. The control method for the refrigeration system according to claim 5, characterized in that, The process of obtaining the temperature parameters and the heating power parameters of the heating device includes: Obtain the target temperature; Obtain the measured temperature; Obtain the actual power output value of the heating device; Obtain the deviation between the measured temperature and the target temperature.

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