Energy-saving control refrigerating system

Abstract

The invention discloses an energy-saving control refrigerating system which comprises a compressor, a condenser, an expansion mechanism, an evaporator, a bypass adjusting loop, a variable-capacity liquid storage device and a main controller. The bypass adjusting loop comprises a first branch pipeline and an electric control flow valve, one end of the first branch pipeline is connected to an outlet of the evaporator, and the other end of the first branch pipeline is connected to an air suction port of the compressor; the variable-capacity liquid storage device is connected with an outlet of the evaporator through a second branch pipeline; the main controller is electrically connected with the variable-capacity liquid storage device and the electric control flow valve, and the main controller is configured to obtain the temperature Tout and the pressure Pout of a refrigerant at an outlet of the evaporator and calculate the superheat degree of the outlet of the evaporator under the condition that the refrigerating system operates in a steady-state mode; and based on the superheat degree and a preset target superheat interval, the opening degree of the electric control flow valve and the volume of the variable-volume liquid storage device are adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration systems, and particularly to an energy-saving controlled refrigeration system. Background Art

[0002] The energy efficiency level of a refrigeration system directly affects the operating cost and energy consumption of the entire system. In traditional refrigeration systems, in order to adjust the flow state of the refrigerant and the system load, in some improved solutions, an electronically controlled expansion valve, a variable-frequency compressor, and sensors are introduced to adjust parameters such as the evaporation temperature and superheat degree, so as to improve the system's response ability to load fluctuations.

[0003] Chinese invention patent CN108317670A discloses an energy-saving control method and system for a refrigeration system based on machine learning. By collecting the ambient temperature, target temperature, compressor operating state, etc., a feature vector is constructed and input into a training model, and energy-saving control parameters are output, and an execution device such as the fan speed and compressor frequency is dynamically adjusted by a controller. However, this solution highly depends on the prediction results of the machine learning model, the model decision lacks transparency, it is difficult to cope with the dynamic changes under complex operating conditions, and problems such as response lag or cumulative adjustment error are likely to occur in actual operation.

[0004] Therefore, there is an urgent need for an energy-saving controlled refrigeration system that has higher adjustment stability and control accuracy under variable operating conditions and can effectively coordinate the system operating state and energy efficiency performance. Summary of the Invention

[0005] The present invention provides an energy-saving controlled refrigeration system to solve the technical problems in the prior art that highly depend on the prediction results of the machine learning model, thus being difficult to cope with the dynamic changes under complex operating conditions, and being prone to response lag or cumulative adjustment error in actual operation.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: The present invention provides an energy-saving controlled refrigeration system, including: a compressor, a condenser, an expansion mechanism, and an evaporator. The exhaust port of the compressor is communicated with the inlet of the condenser, the outlet of the condenser is communicated with the inlet of the evaporator via the expansion mechanism, and the outlet of the evaporator is communicated with the suction port of the compressor to form a closed refrigeration cycle; The system further includes a bypass adjustment circuit, a variable-capacity liquid reservoir, and a main controller; The bypass adjustment circuit includes a first branch pipeline and an electronically controlled flow valve. One end of the first branch pipeline is connected to the outlet of the evaporator, and the other end is connected to the suction port of the compressor. The electronically controlled flow valve is used to adjust the flow ratio of the gas phase and the liquid phase of the refrigerant led out from the outlet of the evaporator that enters the suction port of the compressor; The variable - capacity liquid reservoir is connected to the outlet of the evaporator through a second branch pipeline, and is used to store the refrigerant that has not been completely vaporized at the outlet of the evaporator; The main controller is electrically connected to the variable - capacity liquid reservoir and the electronically controlled flow valve. The main controller is configured to: when the refrigeration system is operating in a steady - state mode, obtain the refrigerant temperature Tout and pressure Pout at the outlet of the evaporator, and calculate the superheat degree at the outlet of the evaporator according to the following formula: , where is the saturation temperature at the pressure Pout; Based on the superheat degree SH and the preset target superheat range , adjust the opening degree of the electronically controlled flow valve and the volume of the variable - capacity liquid reservoir.

[0007] In an alternative embodiment, the variable - capacity liquid reservoir includes a liquid - storage cavity, a variable - volume structure, and a linkage driving assembly; The variable - volume structure adopts at least one of a flexible diaphragm, a deformable airbag, or a movable piston; The linkage drive adopts at least one of a float mechanism, a temperature - sensitive expansion cavity, or an electric push - rod device; The linkage driving assembly is connected to the variable - volume structure and adjusts the volume of the variable - capacity liquid reservoir under the control of the main controller.

[0008] In an alternative embodiment, the variable - volume structure adopts a movable piston, and the linkage driving assembly adopts an electric push - rod device including a stepper motor, a lead - screw transmission mechanism, and a stroke sensor; The main controller determines the adjustment amount of the volume of the variable - capacity liquid reservoir based on the deviation between the superheat degree SH at the outlet of the evaporator and the preset target superheat degree SH target through the following formula and the target displacement amount of the movable piston ( ), .

[0009] where k is a preset volume adjustment sensitivity coefficient, and A is the effective cross - sectional area of the movable piston; The main controller outputs the number of pulses and direction signals for controlling the stepper motor according to the difference between the current actual position of the movable piston collected by the stroke sensor and the target displacement amount The stepping motor rotates under the control of the main controller. The lead screw drive mechanism converts the rotational motion of the stepping motor into linear motion, driving the connected movable piston to move axially within the liquid storage cavity to adjust the effective volume of the variable-capacity liquid reservoir.

[0010] In an alternative embodiment, the variable-volume structure employs a deformable airbag disposed inside the liquid storage cavity. The linkage drive assembly uses a temperature-sensitive expansion cavity filled with a thermosensitive working medium. The deformable airbag communicates with the temperature-sensitive expansion cavity to form a sealed variable-volume cavity. The main controller determines the heating power of the temperature-sensitive expansion cavity based on the superheat SH at the outlet of the evaporator through the following formula:

[0011] where α is a preset expansion response coefficient. The main controller outputs a heating signal for controlling the controllable heating element. The controllable heating element is in thermal contact with the temperature-sensitive expansion cavity and heats the temperature-sensitive expansion cavity under the control of the main controller. The thermosensitive working medium filled in the temperature-sensitive expansion cavity expands in volume when the temperature in the temperature-sensitive expansion cavity rises. The deformable airbag expands, and the effective volume of the variable-capacity liquid reservoir decreases.

[0012] In an alternative embodiment, the variable-volume structure uses a flexible diaphragm disposed inside the liquid storage cavity to separate the liquid cavity part and the gas cavity part. The linkage drive assembly uses a float mechanism disposed inside the liquid storage cavity, including a float, a mechanical link, and a spring-loading structure. The float mechanism floats passively with the change of the liquid level in the liquid storage cavity. One end of the flexible diaphragm is connected to the float through the spring-loading structure and the mechanical link. The main controller, when SH > SH max controls the opening degree of the electronically controlled flow valve to increase. The liquid level in the liquid storage cavity rises, the float floats upward, driving the spring-loading structure and the mechanical link to drive the flexible diaphragm to bend axially towards the gas cavity part, reducing the effective volume of the variable-capacity liquid reservoir. The main controller, when SH < SH min controls the opening degree of the electronically controlled flow valve to decrease. The liquid level in the liquid storage cavity drops, the float floats downward, driving the spring-loading structure and the mechanical link to drive the flexible diaphragm to bend axially towards the liquid cavity part, increasing the effective volume of the variable-capacity liquid reservoir.

[0013] In an alternative embodiment, the main controller is configured with a mode adjustment module for dividing the operating modes of the refrigeration system into a pre-cooling mode, the steady-state mode, a buffer mode, and a protection mode; when the refrigeration system is started for the first time, restarted after a long shutdown, and / or the evaporator temperature is higher than the set start threshold, the mode adjustment module controls the refrigeration system to enter the pre-cooling mode for operation, and / or, when the compressor runs continuously for more than a preset operation duration, the temperature of the evaporator reaches a preset range for more than a preset temperature duration, and / or the superheat SH is within the preset target superheat range for more than a preset steady-state duration, the mode adjustment module controls the refrigeration system to enter the steady-state mode for operation, and / or, when the temperature at the outlet of the evaporator rises or falls by more than a preset range within a short period of time, and / or the superheat SH is greater than SH max and the deviation exceeds a preset deviation value, the mode adjustment module controls the refrigeration system to enter the buffer mode for operation, and / or, when the pressure sensor in the refrigeration system detects that the pressure exceeds a preset high-pressure threshold, and / or the current sensor in the refrigeration system detects that the input current of the compressor exceeds the protection upper limit, and / or the superheat SH is outside the preset target superheat range for more than a preset non-steady-state duration, the mode adjustment module controls the refrigeration system to enter the protection mode for operation.

[0014] In an alternative embodiment, in the pre-cooling mode, at least one of the following operating strategies is adopted: the compressor operates at a speed higher than the preset pre-cooling speed, the electronically controlled flow valve is in a closed state or less than the preset pre-cooling opening degree, and the variable capacity liquid reservoir maintains the maximum effective volume state; and / or, in the buffer mode, at least one of the following operating strategies is adopted: controlling the compressor to operate at a preset buffer frequency or operate in a preset pulse intermittent manner, and the electronically controlled flow valve is in a preset medium buffer opening degree state; and / or, in the protection mode, at least one of the following operating strategies is adopted: reducing the operating frequency of the compressor or stopping the operation of the compressor, restricting the electronically controlled flow valve below the preset protection opening degree, controlling the bypass adjustment circuit to be fully opened or closed, starting the alarm module included in the main controller and recording the current operating data.

[0015] In an alternative embodiment, the refrigeration system further includes a heat recovery branch; The heat recovery branch includes a micro heat exchanger with an inlet connected to the exhaust port of the compressor or the outlet of the condenser and an outlet connected to the inlet of the evaporator, for transferring the heat at the exhaust port of the compressor or the outlet of the condenser to the inlet of the evaporator.

[0016] In an alternative embodiment, the heat recovery branch further includes a thermosensor and a control valve, and the control valve is connected to the micro heat exchanger; The thermosensor is configured to collect a target temperature for controlling the start and stop of heat recovery; When the target temperature meets the preset heat recovery start condition, the main controller outputs a control valve opening signal to control the control valve to be in an open state, and the high-temperature refrigerant discharged from the exhaust port of the compressor or the outlet of the condenser flows through the micro heat exchanger, and the micro heat exchanger transfers heat to the inlet of the evaporator; When the target temperature meets the preset heat recovery stop condition, the main controller outputs a control valve closing signal to control the control valve to be in a closed state, blocking the heat energy recovery branch.

[0017] In an alternative embodiment, the thermosensor is disposed on the ambient side of the refrigeration system and is configured to collect the current ambient temperature T env , and the preset heat recovery start condition is a target heat exchange power calculated based on the following formula greater than a preset power threshold:

[0018] where β is a heat exchange adjustment proportionality coefficient, and T set is a preset judgment threshold; and / or, the thermosensor is disposed at the inlet of the evaporator and is configured to collect the temperature T in at the inlet of the evaporator, and the preset heat recovery start condition is T in < T min , where T min is a preset lower limit threshold; and / or, the thermosensor is disposed at the exhaust port of the compressor and is configured to collect the temperature T out1 at the exhaust port of the compressor, and the preset heat recovery start condition is T out1 > T max , where T max is a preset upper limit threshold; and / or, disposed at the inlet of the evaporator and the outlet of the condenser and configured to collect the temperature T in at the inlet of the evaporator and the temperature T out2 at the outlet of the condenser, and the preset heat recovery start condition is (T out2 - T in ) > ΔT th , where ΔT th is a preset temperature difference threshold.

[0019] The beneficial effects brought by the technical solution provided by the present invention at least include: The energy-saving controlled refrigeration system provided by the present invention realizes precise regulation of the superheat of the refrigerant at the evaporator outlet by setting up a bypass regulation loop, an electronically controlled flow valve and a variable-capacity liquid receiver, ensuring that the refrigeration system can quickly respond to load changes under variable working conditions and maintain the stable operation of the system. The coordinated regulation of the variable-capacity liquid receiver and the electronically controlled flow valve can dynamically adjust the gas-liquid ratio and liquid storage capacity of the refrigerant, effectively avoiding the influence of incomplete vaporization of the refrigerant on the operation of the compressor and improving the energy efficiency ratio of the system. By adopting a design scheme of a variety of variable-capacity structures and linkage drive components, the regulating mechanism of the system is simple and reliable in structure, high in control sensitivity, and easy to realize automatic control. The main controller accurately calculates and adjusts the liquid receiver volume and valve opening according to the feedback information of the superheat at the evaporator outlet, ensuring smooth switching between multiple operating modes such as the steady-state mode, the buffer mode and the protection mode, and effectively preventing the system from operating overloaded or unstably. In addition, the present invention introduces a heat recovery branch and a thermosensitive sensor, and automatically controls the start and stop of the heat energy recovery device by collecting the temperature information of the compressor exhaust port, the condenser outlet and the evaporator inlet in real time according to the preset temperature threshold and temperature difference conditions, improving the overall energy utilization rate of the refrigeration system and reducing energy consumption. Compared with the prior art, the present invention does not rely on a complex machine learning model, avoids the problems of prediction error and response lag, improves the transparency and feasibility of the control strategy, improves the energy-saving effect and system stability, and meets the energy-saving requirements under complex working conditions. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0021] Figure 1 It is a schematic structural diagram of an energy-saving controlled refrigeration system provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a variable-capacity liquid receiver provided by an embodiment of the present invention. Detailed Embodiments

[0022] The present invention will be described in detail below with reference to the drawings and specific embodiments. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0023] In the present invention, words such as "in a possible embodiment", "exemplary", or "for example" are used to give examples, illustrations, or explanations. Any embodiment or design described as "in a possible embodiment", "exemplary", or "for example" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of words such as "in a possible embodiment", "exemplary", or "for example" is intended to present the relevant concepts in a specific manner.

[0024] Figure 1 The following is a schematic diagram of the architecture of an energy-saving control refrigeration system provided by an embodiment of the present invention. As Figure 1 shown, an energy-saving control refrigeration system 10 includes: a compressor 101, a condenser 102, an expansion mechanism 103, and an evaporator 104. The exhaust port of the compressor 101 is communicated with the inlet of the condenser 102. The outlet of the condenser 102 is communicated with the inlet of the evaporator 104 via the expansion mechanism 103. The outlet of the evaporator 104 is communicated with the suction port of the compressor 101 to form a closed refrigeration circuit; The system further includes a bypass adjustment circuit 105, a variable capacity liquid receiver 106, and a main controller 107; The bypass adjustment circuit 105 includes a first branch pipeline 1051 and an electronically controlled flow valve 1052. One end of the first branch pipeline 1051 is connected to the outlet of the evaporator 104, and the other end is connected to the suction port of the compressor 101. The electronically controlled flow valve 1052 is used to adjust the flow ratio of the gas phase and the liquid phase of the refrigerant led out from the outlet of the evaporator 104 that enters the suction port of the compressor 101; The variable capacity liquid receiver 106 is connected to the outlet of the evaporator 104 through a second branch pipeline 108 and is used to store the refrigerant that is not completely vaporized at the outlet of the evaporator 104; The main controller 107 is electrically connected to the variable capacity liquid receiver 106 and the electronically controlled flow valve 1052. The main controller 107 is configured to: When the refrigeration system is operating in a steady state mode, obtain the refrigerant temperature Tout and pressure Pout at the outlet of the evaporator 104, and calculate the superheat degree at the outlet of the evaporator 104 according to the following formula:

[0025] where is the saturation temperature at the pressure Pout; Based on the superheat degree SH and the preset target superheat range , adjust the opening degree of the electronically controlled flow valve 1052 and the volume of the variable capacity liquid reservoir 106.

[0026] In this embodiment, a basic refrigeration circuit composed of a compressor, a condenser, an expansion mechanism, and an evaporator is provided, and the basic refrigeration circuit is assisted by a bypass adjustment circuit, a variable capacity liquid reservoir, and a main controller. According to the subcooling degree and the gas-liquid phase ratio of the refrigerant at different stages in the refrigeration circuit, the opening degree of the electronically controlled flow valve and the volume of the variable capacity liquid reservoir are dynamically adjusted, so that a part of the liquid phase remains in the evaporator outlet, reducing the suction enthalpy value at the compressor inlet, thereby reducing the compression power consumption and the overall energy consumption, and achieving energy-saving control.

[0027] Among them, the bypass adjustment circuit is a functional circuit provided for adjusting the gas-liquid flow ratio, which includes a first branch pipeline and an electronically controlled flow valve. The electronically controlled flow valve can be, for example, a micro-flow adjustment solenoid valve based on stepping motor control, which uses a micro stepping motor to drive a screw propelling rod to achieve fine displacement control of the needle valve, supports an opening degree adjustment of 0.01 mm level, and is suitable for variable load small refrigeration systems. The spool position is real-time fed back by an optical encoder, and the closed-loop control improves the adjustment accuracy; it can also be an intelligent flow valve based on a thermally deformed alloy, which uses a shape memory alloy wire (such as NiTi) as a driving element, and the temperature change causes the spool displacement, and can achieve non-electric drive control, and only adaptively controls the opening degree through a thermosensitive feedback device; it can also be a double-chamber differential pressure adjustment type electronically controlled flow valve, which is provided with a front and rear chamber pressure balance mechanism, and the electronic control driver only responsible for adjusting the opening degree of the balance hole, and uses the system pressure to adaptively adjust the position of the main spool, thereby controlling the overall flow; and so on. In practical applications, it can be set according to different requirements, and this embodiment does not limit this. In addition, in the bypass adjustment circuit, a gas-liquid mixing buffer chamber can be provided between the first branch pipeline and the suction port of the compressor, and a turbulence suppression structure or a gas-liquid guiding baffle is provided inside, which is used to achieve uniform mixing of the gas phase entering the branch and the main circulation suction gas. The electronically controlled flow valve is used to adjust the flow ratio of the gas phase and the liquid phase of the refrigerant led out from the outlet of the evaporator and entering the suction port of the compressor. Specifically, a part of the refrigerant led out from the outlet of the evaporator can be shunted through the variable capacity liquid reservoir connected to the outlet of the evaporator through a second branch pipeline. That is to say, the variable capacity liquid reservoir and the bypass adjustment circuit together constitute a phase state adjustment mechanism on the outlet side of the evaporator, so as to achieve precise control of the refrigerant phase change path and achieve the purpose of energy-saving operation of the system.

[0028] In an optional embodiment, Figure 2 is a schematic structural diagram of the variable capacity liquid reservoir provided by the embodiment of the present invention, as Figure 2 shown, the variable capacity liquid reservoir 106 includes a liquid storage cavity 1061, a variable volume structure 1062, and a linkage drive assembly 1063; The variable capacitance structure adopts at least one of a flexible diaphragm, a deformable airbag or a movable piston; The linkage drive adopts at least one of a float mechanism, a temperature-sensitive expansion chamber or an electric push rod device; The linkage drive assembly is connected to the variable capacitance structure and adjusts the volume of the variable-capacity liquid reservoir under the control of the main controller.

[0029] For example, a movable piston can be combined with a float mechanism and a temperature-sensitive expansion chamber to adjust the volume of the variable-capacity liquid reservoir. The temperature-sensitive expansion chamber (such as a liquid-filled cavity) expands due to temperature changes and pushes the movable piston to move. The piston movement changes the volume of a certain section of the liquid storage cavity or applies pressure to regulate the refrigerant flow. The float mechanism can be installed in the liquid cavity controlled by the piston to sense the change in liquid level. The temperature-sensitive expansion chamber is responsible for temperature-responsive driving, and the float completes the liquid level response linkage. More specifically, for example, at the outlet of the evaporator, the temperature-sensitive expansion drives the piston, causing the liquid level in the liquid storage cavity to rise and fall, triggering the float to drive the mechanical link to open or close the bypass port.

[0030] Another example is that a deformable airbag can be combined with a float mechanism and an electric push rod device to adjust the volume of the variable-capacity liquid reservoir. The deformable airbag is compressed or released by the push rod, changing its volume and affecting the surrounding liquid level or cavity pressure. The float mechanism is installed above the airbag or in the surrounding liquid to monitor the change in liquid level caused by the deformation of the airbag. The electric push rod can precisely control the volume change of the airbag to achieve precise liquid level control, and can be used to construct a liquid level adjustment structure with electronic control or mechanical feedback. More specifically, for example, the airbag pushes the liquid to expand, the position of the float changes and links the bypass valve to form an electronically controlled liquid drainage structure with a self-checking function.

[0031] Another example is that a flexible diaphragm can be combined with a temperature-sensitive expansion chamber and an electric push rod device to adjust the volume of the variable-capacity liquid reservoir. The flexible diaphragm serves as a deformable interface to separate gas-liquid or cold-hot fluids. The temperature-sensitive expansion chamber generates pressure when the temperature changes and pushes the flexible diaphragm to deform and push the control structure (such as a needle valve). Or, the electric push rod directly acts on the diaphragm to adjust the pressure and volume of the downstream cavity. The flexible diaphragm can act as a response element or a sealing transmission medium, reducing friction and improving response. More specifically, for example, when the superheat of the evaporator increases, the expansion chamber drives the flexible diaphragm to push the bypass port open, or the push rod compensates for the pressure change to control the throttling path.

[0032] In addition, other methods can also be used to adjust the volume of the variable-capacity liquid reservoir, which can be set according to different requirements in actual applications, and this embodiment does not limit this.

[0033] In an alternative embodiment, the variable capacitance structure employs a movable piston, and the linkage drive assembly uses an electric push rod device including a stepper motor, a lead screw transmission mechanism, and a stroke sensor; The main controller determines the adjustment amount of the volume of the variable capacity liquid reservoir based on the deviation between the superheat SH at the outlet of the evaporator and the preset target superheat SH target through the following formula to obtain the target displacement of the movable piston : : ( )

[0034] where k is a preset volume adjustment sensitivity coefficient, and A is the effective cross-sectional area of the movable piston; The main controller outputs a pulse number and a direction signal for controlling the stepper motor according to the difference between the current actual position of the movable piston collected by the stroke sensor and the target displacement ; The stepper motor rotates under the control of the main controller, and the lead screw transmission mechanism converts the rotational motion of the stepper motor into a linear motion, driving the connected movable piston to move axially in the liquid storage cavity to adjust the effective volume of the variable capacity liquid reservoir.

[0035] Exemplarily, the preset target superheat SH target can be determined in advance by experience or performance simulation, for example, it can be 5 - 10 °C. The preset volume adjustment sensitivity coefficient k represents how much liquid volume needs to be adjusted for every 1 °C deviation, and can be determined through engineering commissioning, for example, it can be 0.1 - 5 L / °C, or k can be adaptively adjusted according to the ambient temperature or load level. In addition, the distance that the piston needs to move can be obtained based on the liquid volume change and the cross-sectional area. When the controller sends a pulse signal to the stepper motor, each pulse represents a fixed angular rotation step, and at the same time, the direction (clockwise / counterclockwise) is specified. The controller can also set the frequency and speed to achieve uniform or variable speed driving. Therefore, the main controller outputs a control signal corresponding to the number of steps and direction to the stepper motor according to the difference between the actual position and the target displacement, driving the lead screw to rotate, thereby realizing the linear advancement or retraction of the piston and completing the adjustment of the liquid reservoir volume.

[0036] In an alternative embodiment, the variable capacitance structure uses a deformable airbag disposed inside the liquid storage cavity, and the linkage drive assembly uses a temperature-sensitive expansion cavity filled with a thermosensitive working medium. The deformable airbag is connected to the temperature-sensitive expansion cavity to form a sealed variable volume cavity; The main controller determines the heating power of the temperature-sensitive expansion chamber based on the superheat SH at the evaporator outlet through the following formula:

[0037] where α is a preset expansion response coefficient; The main controller outputs a heating signal for controlling the controllable heating element according to the heating power ; The controllable heating element is in thermal contact with the temperature-sensitive expansion chamber and heats the temperature-sensitive expansion chamber under the control of the main controller. The thermosensitive working medium filled in the temperature-sensitive expansion chamber expands in volume when the temperature in the temperature-sensitive expansion chamber rises, the deformable airbag expands, and the effective volume of the variable-capacity liquid reservoir decreases.

[0038] Exemplarily, the temperature-sensitive expansion chamber and the airbag can be connected by a high-temperature and pressure-resistant hose, and the inside can be the same gas medium, such as air, nitrogen or fluoride gas. The medium is heated under the control of the main controller, causing volume expansion and driving the deformation of the airbag.

[0039] In an alternative embodiment, the variable-volume structure employs a flexible diaphragm disposed inside the liquid storage cavity for separating the liquid cavity portion and the gas cavity portion. The linkage drive assembly employs a float mechanism disposed inside the liquid storage cavity and including a float, a mechanical link, and a spring-loading structure. The float mechanism floats passively with the change in the liquid level inside the liquid storage cavity, and one end of the flexible diaphragm is connected to the float through the spring-loading structure and the mechanical link; When SH > SH max , the main controller controls the opening of the electronically controlled flow valve to increase, the liquid level inside the liquid storage cavity rises, the float floats upward, driving the spring-loading structure and the mechanical link to drive the flexible diaphragm to axially bend towards the gas cavity portion, reducing the effective volume of the variable-capacity liquid reservoir; When SH < SH min , the main controller controls the opening of the electronically controlled flow valve to decrease, the liquid level inside the liquid storage cavity drops, the float floats downward, driving the spring-loading structure and the mechanical link to drive the flexible diaphragm to axially bend towards the liquid cavity portion, increasing the effective volume of the variable-capacity liquid reservoir.

[0040] Exemplarily, when the liquid level rises, the floating ball floats under the action of the buoyancy of the liquid. Through the mechanical link, the upward floating of the floating ball is converted into an upward thrust, which pushes the flexible diaphragm to deform, changing the effective volume of the liquid storage cavity. The spring-loaded structure provides deformation limit, buffering, or resilience to ensure the stability of the system. The flexible diaphragm can be made of an elastic material resistant to refrigerant corrosion (such as rubber, fluororubber, silica gel, or polyurethane, etc.), installed inside the liquid storage device, dividing the liquid storage cavity into two parts: the liquid cavity part (storing refrigerant liquid) and the gas cavity part (storing refrigerant gas, mainly the gaseous refrigerant returned from the evaporator and its gas phase space). One side of the flexible diaphragm is in direct contact with the liquid, and the other side is the gas phase space. The edge can be fixed to the inner wall of the liquid storage device through a sealing structure (such as a flange, a clamp, or welding) to ensure tightness and prevent gas-liquid mixing. The spring can be installed in the transmission mechanism between the mechanical link and the flexible diaphragm, or directly installed at the edge mounting structure of the flexible diaphragm.

[0041] In the evaporator, the low-pressure liquid refrigerant absorbs heat and gradually vaporizes. Ideally, it is completely vaporized into gas just at the end of the evaporator. However, in actual operating conditions, there are often cases where some liquid is not completely vaporized, forming a gas-liquid mixture. The compressor compresses "refrigerant gas". The higher the enthalpy value of the inhaled refrigerant, that is, the greater the heat content per unit mass, the more work is required during compression. If there are some incompletely vaporized liquid droplets in the inhaled refrigerant (i.e., in a colder state and lower enthalpy value), the energy consumption required for compression will decrease. Therefore, the variable capacity liquid storage device is used to temporarily retain the liquid refrigerant at the evaporator outlet and control the ratio of the gas-liquid phases of the refrigerant flowing into the compressor. By adjusting the volume of the variable capacity liquid storage device, some of the incompletely vaporized liquid refrigerant is selectively retained at the evaporator outlet, so as to control the refrigerant entering the compressor to have a lower specific enthalpy value, thereby reducing the compression load and energy consumption of the compressor.

[0042] In addition, one-way valves can be set at the inlet and outlet of the variable capacity liquid storage device to restrict the refrigerant in the liquid storage device from flowing back to the main cycle only when the pressure difference meets the conditions, avoiding liquid backflow. In actual applications, it can be set according to different requirements, and this embodiment does not make any limitations in this regard.

[0043] In this embodiment, the entire operating cycle of the refrigeration system can be divided into multiple modes (such as pre-cooling, steady state, buffering, protection), and each mode adopts a different load control strategy. Energy conservation is optimized through the entire scheduling sequence and switching points, which is applicable to periodic fluctuating load scenarios.

[0044] In an alternative embodiment, the main controller is configured with a mode adjustment module for dividing the operating modes of the refrigeration system into a precooling mode, the steady state mode, a buffer mode, and a protection mode; when the refrigeration system is started for the first time, restarted after a long shutdown, and / or the evaporator temperature is higher than the set startup threshold, the mode adjustment module controls the refrigeration system to enter the precooling mode for operation, and / or, when the compressor continuously operates for more than a preset operation duration, the temperature of the evaporator reaches a preset range for more than a preset temperature duration, and / or the superheat SH is within the preset target superheat range for more than a preset steady state duration, the mode adjustment module controls the refrigeration system to enter the steady state mode for operation, and / or, when the temperature at the outlet of the evaporator rises or falls by more than a preset range within a short period of time, and / or the superheat SH is greater than SH max and the deviation exceeds a preset deviation value, the mode adjustment module controls the refrigeration system to enter the buffer mode for operation, and / or, when the pressure sensor in the refrigeration system detects that the pressure exceeds a preset high pressure threshold, and / or the current sensor in the refrigeration system detects that the input current of the compressor exceeds the protection upper limit, and / or the superheat SH is outside the preset target superheat range for more than a preset non-steady state duration, the mode adjustment module controls the refrigeration system to enter the protection mode for operation.

[0045] Exemplarily, the mode switching timing can also be determined based on the comparison result between the slope change amount ΔQ / Δt of the refrigeration system load change and the preset threshold Q th the specific mode is determined based on the deviation range ΔSH between the superheat SH at the outlet of the evaporator and its time average value SH avg and the current mode type is selected using an empirical rule base based on the start-stop frequency, operating time, or vibration intensity change of the compressor, and so on. In addition, the operating parameters within different modes can include but are not limited to the target frequency of the compressor, the opening degree of the expansion mechanism, the target volume of the liquid receiver, and the target opening degree of the electronically controlled flow valve, and so on.

[0046] The main controller can adopt different operation control strategies for the compressor, expansion mechanism, electronically controlled flow valve, variable capacity liquid receiver, etc. in different modes.

[0047] In an alternative embodiment, in the pre-cooling mode, at least one of the following operating strategies is adopted: the compressor operates at a speed higher than a preset pre-cooling speed, the electronically controlled flow valve is in a closed state or a state with an opening less than a preset pre-cooling opening, and the variable capacity liquid reservoir maintains the maximum effective volume state; and / or, in the buffering mode, at least one of the following operating strategies is adopted: controlling the compressor to operate at a preset buffering frequency or operate intermittently with a preset pulse, and the electronically controlled flow valve is in a state with a preset medium buffering opening; and / or, in the protection mode, at least one of the following operating strategies is adopted: reducing the operating frequency of the compressor or stopping the operation of the compressor, restricting the electronically controlled flow valve to be below a preset protection opening, controlling the bypass adjustment circuit to be fully opened or closed, starting the alarm module included in the main controller and recording the current operating data.

[0048] Exemplarily, the pre-cooling mode is used to quickly reduce the temperature of the evaporator to the target cooling area. The superheat SH may temporarily deviate from the target value. The main controller controls the compressor to operate at medium and high speeds, giving priority to quickly establishing the refrigeration cycle. The opening of the expansion mechanism is based on the principle of preferentially reducing the temperature of the evaporator. The electronically controlled flow valve is in a closed state or a small opening state (such as ≤ 10%) to prevent liquid phase from directly entering the compressor. The variable capacity liquid reservoir maintains the maximum effective volume state to absorb the excess unvaporized liquid. The buffering mode is used to buffer the system instability caused by sudden variable loads, avoid directly entering the protection mode, and switch back to the steady state mode after restoring stable operation. The main controller reduces the compressor frequency to the minimum or operates intermittently (pulse load). The electronically controlled flow valve maintains a middle opening to reduce the influence of liquid phase fluctuations. The variable capacity liquid reservoir temporarily adjusts its volume to absorb and release excess liquid, and the bypass adjustment circuit is opened to achieve rapid gas-liquid shunt adjustment. The protection mode is used to prevent risks such as compressor overload, too high pressure or system failure.

[0049] In this embodiment, a micro heat exchange branch can be set in the refrigeration system to recover the exhaust heat of the compressor or the waste heat of the condenser, which is used to increase or maintain the temperature of key nodes in the system. The residual heat at the hot end is used for temperature control during low-load operation, reducing unnecessary energy consumption. This is not energy saving achieved through intelligent control, but energy self-recovery adjustment of the structural physical circuit, which is especially suitable for winter or low-load operation conditions.

[0050] In an alternative embodiment, the refrigeration system further includes a heat recovery branch; The heat recovery branch includes a micro heat exchanger with an inlet connected to the exhaust port of the compressor or the outlet of the condenser and an outlet connected to the inlet of the evaporator, for transferring the heat at the exhaust port of the compressor or the outlet of the condenser to the inlet of the evaporator.

[0051] Exemplarily, the structure of the micro heat exchanger can be finned tube type, microchannel structure, phase change heat storage structure, etc., and the phase change material is paraffin, fluoride or molten metal material, etc., to improve the heat exchange efficiency and achieve the buffer temperature regulation function.

[0052] The main controller can determine whether to turn on the heat recovery branch based on the current operating state parameters of the system (such as the temperature at the evaporator outlet, the temperature of the compressor discharge, the condensation pressure, etc.).

[0053] In an alternative embodiment, the heat recovery branch further includes a thermosensitive sensor and a control valve, and the control valve is connected to the micro heat exchanger; The thermosensitive sensor is used to collect the target temperature for controlling the start and stop of heat recovery; When the target temperature meets the preset heat recovery start condition, the main controller outputs a control valve opening signal to control the control valve to be in an open state, and the high-temperature refrigerant discharged from the exhaust port of the compressor or the outlet of the condenser flows through the micro heat exchanger, and the micro heat exchanger transfers heat to the inlet of the evaporator; When the target temperature meets the preset heat recovery stop condition, the main controller outputs a control valve closing signal to control the control valve to be in a closed state, blocking the heat energy recovery branch.

[0054] Exemplarily, the opening and closing of the heat recovery branch can be achieved through a control valve, such as a solenoid valve, a check valve, a proportional control valve or a thermosensitive valve, etc., for controlling the on-off or heat exchange intensity of the heat recovery branch according to the system load state. In addition, it can also include a heat insulation jacket layer to cover the pipe sections that do not participate in heat exchange in the heat recovery branch to reduce heat dissipation to the environment.

[0055] In an alternative embodiment, the thermosensitive sensor is arranged on the environment side of the refrigeration system and is used to collect the current ambient temperature T env , and the preset heat recovery start condition is the target heat exchange power calculated based on the following formula greater than the preset power threshold:

[0056] where β is the heat exchange adjustment proportional coefficient, and T set is the preset judgment threshold; and / or, the thermosensitive sensor is arranged at the inlet of the evaporator and is used to collect the temperature T at the inlet of the evaporator in , and the preset heat recovery start condition is T in <T min , where T min is the preset lower limit threshold; And / or, the thermosensor is disposed at the exhaust port of the compressor and is used to collect the temperature T of the exhaust port of the compressor. out1 , the preset heat recovery start condition is T out1 > T max , where T max is a preset upper limit threshold; And / or, it is disposed at the inlet of the evaporator and the outlet of the condenser and is used to collect the temperature T of the inlet of the evaporator in and the temperature T of the outlet of the condenser out2 , the preset heat recovery start condition is (T out2 - T in ) > ΔT th , where ΔT th is a preset temperature difference threshold.

[0057] Exemplarily, in the precooling mode, the main controller can control the control valve to conduct, and a part of the high-temperature refrigerant at the exhaust port of the compressor or the outlet of the condenser flows along the heat recovery branch, and the low-temperature refrigerant at the inlet of the evaporator is heated through heat exchange. A throttle orifice plate or a microchannel flow path structure can be arranged in the heat recovery branch to limit the refrigerant flow rate to 10% - 30% of the compressor exhaust flow rate, preventing the system from oscillating or the risk of liquid hammer caused by too fast heat transfer.

[0058] Based on the above structure, the energy-saving control refrigeration system provided by the present invention realizes precise adjustment of the superheat of the refrigerant at the outlet of the evaporator by setting a bypass adjustment loop, an electronically controlled flow valve and a variable capacity liquid reservoir, ensuring that the refrigeration system can quickly respond to load changes under variable working conditions and maintain the stable operation of the system. The coordinated adjustment of the variable capacity liquid reservoir and the electronically controlled flow valve can dynamically adjust the gas-liquid ratio and liquid storage capacity of the refrigerant, effectively avoiding the influence of incomplete vaporization of the refrigerant on the operation of the compressor and improving the energy efficiency ratio of the system. By adopting the design scheme of various variable volume structures and linkage drive components, the adjustment mechanism of the system is simple and reliable, with high control sensitivity and easy to realize automatic control. The main controller accurately calculates and adjusts the liquid reservoir volume and valve opening according to the feedback information of the superheat at the outlet of the evaporator, ensuring smooth switching between multiple operation modes such as the steady state mode, the buffer mode and the protection mode, and effectively preventing the system from running overloaded or unstably. In addition, the present invention introduces a heat recovery branch and a thermosensor, and by collecting the temperature information of the compressor exhaust port, the condenser outlet and the evaporator inlet in real time, automatically controls the start and stop of the heat energy recovery device according to the preset temperature threshold and temperature difference condition, improving the overall energy utilization rate of the refrigeration system and reducing energy consumption. Compared with the prior art, the present invention does not rely on a complex machine learning model, avoids the problems of prediction error and response lag, improves the transparency and feasibility of the control strategy, enhances the energy-saving effect and system stability, and meets the energy-saving requirements under complex working conditions.

[0059] In addition, it should be noted that the present invention can be provided as a method, an apparatus, or a computer program product. Therefore, the embodiments of the present invention can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0060] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, an embedded processor, or other programmable data processing terminal devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal devices generate a device for implementing the functions specified in one Figure 1 process or multiple processes and / or blocks Figure 1 or multiple blocks.

[0061] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal devices to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in one Figure 1 process or multiple processes and / or blocks Figure 1 or multiple blocks. These computer program instructions can also be loaded onto a computer or other programmable data processing terminal devices, so that a series of operation steps are executed on the computer or other programmable terminal devices to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable terminal devices provide steps for implementing the functions specified in one Figure 1 process or multiple processes and / or blocks Figure 1 or multiple blocks.

[0062] It should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or terminal device comprising said element.

[0063] Finally, it should be noted that the above is the preferred embodiment of the present invention. It should be pointed out that although the preferred embodiments of the present invention have been described, for those skilled in the art of this technology, once the basic creative concept of the present invention is known, without departing from the principle described in the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A refrigeration system with energy-saving control, characterized in that, Comprising: A compressor, a condenser, an expansion mechanism and an evaporator, wherein the exhaust port of the compressor is communicated with the inlet of the condenser, the outlet of the condenser is communicated with the inlet of the evaporator via the expansion mechanism, and the outlet of the evaporator is communicated with the suction port of the compressor to form a closed refrigeration circuit; The system further includes a bypass regulation circuit, a variable-capacity liquid reservoir and a main controller; The bypass regulation circuit includes a first branch pipeline and an electronically controlled flow valve. One end of the first branch pipeline is connected to the outlet of the evaporator, and the other end is connected to the suction port of the compressor. The electronically controlled flow valve is used to regulate the flow ratio of the gas phase and the liquid phase of the refrigerant led out from the outlet of the evaporator and entering the suction port of the compressor; The variable-capacity liquid reservoir is connected to the outlet of the evaporator through a second branch pipeline and is used to store the refrigerant that is not completely vaporized at the outlet of the evaporator; The main controller is electrically connected to the variable-capacity liquid reservoir and the electronically controlled flow valve, and the main controller is configured as: When the refrigeration system is operating in a steady-state mode, obtain the refrigerant temperature Tout and pressure Pout at the outlet of the evaporator, and calculate the superheat degree of the outlet of the evaporator according to the following formula: Among them, is the saturation temperature at the pressure Pout; Based on the superheat SH and a preset target superheat range , adjust the opening degree of the electronically controlled flow valve and the volume of the variable capacity accumulator.

2. The energy-saving controlled refrigeration system according to claim 1, characterized in that, The variable-capacity liquid reservoir includes a liquid storage cavity, a variable-volume structure and a linkage drive assembly; The variable-volume structure adopts at least one of a flexible diaphragm, a deformable airbag or a movable piston; The linkage drive adopts at least one of a float mechanism, a temperature-sensitive expansion cavity or an electric push rod device; The linkage drive assembly is connected to the variable-volume structure and adjusts the volume of the variable-capacity liquid reservoir under the control of the main controller.

3. The energy-saving controlled refrigeration system according to claim 2, characterized in that, The variable-volume structure adopts a movable piston, and the linkage drive assembly adopts an electric push rod device including a stepping motor, a lead screw transmission mechanism and a stroke sensor; The master controller determines the adjustment amount of the volume of the variable capacity liquid reservoir based on the deviation between the superheat SH at the evaporator outlet and the preset target superheat SH target and the target displacement of the movable piston through the following formula : , , Wherein, K is a preset volume adjustment sensitivity coefficient, and A is the effective cross-sectional area of the movable piston; The master controller outputs the number of pulses and direction signals for controlling the stepper motor according to the difference between the current actual position of the movable piston collected by the stroke sensor and the target displacement ; The stepping motor rotates under the control of the main controller, and the lead screw transmission mechanism converts the rotational motion of the stepping motor into a linear motion, driving the connected movable piston to move axially in the liquid storage cavity to adjust the effective volume of the variable-capacity liquid reservoir.

4. The energy-saving controlled refrigeration system according to claim 2, wherein, The variable-volume structure adopts a deformable airbag arranged inside the liquid storage cavity, and the linkage drive assembly adopts a temperature-sensitive expansion cavity filled with a thermosensitive working medium. The deformable airbag is communicated with the temperature-sensitive expansion cavity to form a sealed variable-volume cavity; The main controller determines the heating power of the temperature-sensitive expansion cavity based on the superheat degree SH at the outlet of the evaporator through the following formula: , Wherein, α is a preset expansion response coefficient; The main controller outputs a heating signal for controlling the controllable heating element according to the heating power ; The controllable heating element is in thermal contact with the temperature-sensitive expansion cavity and heats the temperature-sensitive expansion cavity under the control of the main controller. The thermosensitive working medium filled in the temperature-sensitive expansion cavity expands in volume when the temperature in the temperature-sensitive expansion cavity rises, the deformable airbag expands, and the effective volume of the variable-capacity liquid reservoir decreases.

5. The energy-saving controlled refrigeration system according to claim 2, characterized in that, The variable capacitance structure adopts a flexible diaphragm arranged inside the liquid storage cavity, which is used to separate the liquid cavity part and the gas cavity part. The linkage drive assembly adopts a float mechanism arranged inside the liquid storage cavity, including a float ball, a mechanical link rod and a spring loading structure. The float mechanism floats passively with the change of the liquid level in the liquid storage cavity. One end of the flexible diaphragm is connected to the float ball through the spring loading structure and the mechanical link rod; When SH > SH max the main controller controls the opening degree of the electronically controlled flow valve to increase, the liquid level in the liquid storage cavity rises, the floating ball floats upward, drives the spring-loaded structure and the mechanical connecting rod to drive the flexible diaphragm to axially bend towards the gas cavity part, and reduces the effective volume of the variable capacity liquid storage device; When SH < SH min , the master controller controls the opening degree of the electronically controlled flow valve to decrease, the liquid level in the liquid storage cavity drops, the floating ball floats downward, driving the spring-loaded structure and the mechanical connecting rod to drive the flexible diaphragm to axially bend towards the liquid cavity part, increasing the effective volume of the variable-capacity liquid storage device.

6. The energy-saving controlled refrigeration system according to claim 1, wherein The main controller is configured with a mode adjustment module for dividing the operating mode of the refrigeration system into a pre-cooling mode, the steady state mode, a buffer mode and a protection mode; When the refrigeration system is started for the first time, restarted after a long-term shutdown, and / or the temperature of the evaporator is higher than the set start threshold, the mode adjustment module controls the refrigeration system to enter the pre-cooling mode for operation, and / or, When the compressor runs continuously for more than a preset running duration, the temperature of the evaporator reaches a preset interval for more than a preset temperature duration, and / or the superheat SH is within the preset target superheat interval for more than a preset steady state duration, the mode adjustment module controls the refrigeration system to enter the steady state mode for operation, and / or, The temperature at the outlet of the evaporator rises or falls by more than a preset range within a short period of time, and / or the superheat SH is greater than SH max and when the deviation exceeds a preset deviation value, the mode adjustment module controls the refrigeration system to enter the buffer mode for operation, and / or When the pressure sensor in the refrigeration system detects that the pressure exceeds a preset high pressure threshold, and / or the current sensor in the refrigeration system detects that the input current of the compressor exceeds the protection upper limit, and / or the superheat SH is outside the preset target superheat interval for more than a preset non-steady state duration, the mode adjustment module controls the refrigeration system to enter the protection mode for operation.

7. The energy-saving controlled refrigeration system according to claim 6, wherein, In the pre-cooling mode, at least one of the following operating strategies is adopted: the compressor operates at a speed higher than the preset pre-cooling speed, the electronically controlled flow valve is in a closed state or a state less than the preset pre-cooling opening degree, and the variable capacity liquid accumulator maintains the maximum effective volume state; and / or, In the buffer mode, at least one of the following operating strategies is adopted: controlling the compressor to operate at a preset buffer frequency or operate intermittently in a preset pulse, and the electronically controlled flow valve is in a preset medium buffer opening state; and / or, In the protection mode, at least one of the following operating strategies is adopted: reducing the operating frequency of the compressor or stopping the operation of the compressor, restricting the electronically controlled flow valve below the preset protection opening degree, controlling the bypass adjustment circuit to be fully opened or closed, starting the alarm module included in the main controller and recording the current operating data.

8. The energy-saving controlled refrigeration system according to claim 1, characterized in that The refrigeration system further includes a heat recovery branch; The heat recovery branch includes a micro heat exchanger with an inlet connected to the exhaust port of the compressor or the outlet of the condenser and an outlet connected to the inlet of the evaporator, which is used to transfer the heat at the exhaust port of the compressor or the outlet of the condenser to the inlet of the evaporator.

9. The energy-saving controlled refrigeration system according to claim 8, wherein The heat recovery branch further includes a thermosensitive sensor and a control valve, and the control valve is connected to the micro heat exchanger; The thermosensitive sensor is used to collect the target temperature for controlling the start and stop of heat recovery; When the target temperature meets the preset heat recovery start condition, the main controller outputs a control valve opening signal to control the control valve to be in an open state, and the high-temperature refrigerant discharged from the exhaust port of the compressor or the outlet of the condenser flows through the micro heat exchanger, and the micro heat exchanger transfers heat to the inlet of the evaporator; When the target temperature meets the preset heat recovery stop condition, the main controller outputs a control valve closing signal to control the control valve to be in a closed state, blocking the heat energy recovery branch.

10. The energy-saving controlled refrigeration system according to claim 9, characterized in that, The thermosensor is disposed on the ambient side of the refrigeration system and is used to collect the current ambient temperature T env , and the preset heat recovery activation condition is a target heat exchange power calculated based on the following formula greater than a preset power threshold value: where β is a heat exchange adjustment proportionality coefficient, and T set is a preset judgment threshold value; And / or, the thermosensor is disposed at the inlet of the evaporator and is used to collect the temperature T at the inlet of the evaporator in , the preset heat recovery start condition is T in < T min , where T min is a preset lower limit threshold; And / or, the thermosensor is disposed at the exhaust port of the compressor and is used to collect the temperature T of the exhaust port of the compressor out1 , the preset heat recovery start condition is T out1 > T max , where T max is a preset upper limit threshold value; and / or, arranged at the inlet of the evaporator and the outlet of the condenser and used to collect the temperature T at the inlet of the evaporator in and the temperature T at the outlet of the condenser out2 , the preset heat recovery start condition is (T out2 -T in ) > ΔT th , where ΔT th is a preset temperature difference threshold value.

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