Low-temperature heat pump liquid impact prevention and supercooling degree strengthening control method based on dual-mode self-adaptive regulation and control

Abstract

The invention provides a low-temperature heat pump liquid impact prevention and supercooling degree strengthening control method based on dual-mode self-adaptive regulation and control, which comprises the following steps: monitoring the bottom temperature of a gas-liquid separator and the change rate of the temperature, and controlling the supercooling degree of the gas-liquid separator on the basis of the difference value between the temperature and a preset safety critical temperature and the difference value between the change rate and a preset minimum temperature rise rate, constructing a liquid impact risk index; based on the liquid impact risk index, the pulse power excitation intensity is calculated, the number of opened spraying channels is selected according to the pulse power excitation intensity, the pulse duty ratio of each channel is adjusted, the high-temperature gas-state refrigerant is controlled to be injected into the bottom of the gas-liquid separator, and the liquid-state refrigerant is driven to evaporate; generating a mode switching score, and generating a mode switching signal when the mode switching score exceeds a mode switching threshold value and the temperature of the gas-liquid separator reaches a safety lower limit; and according to the mode switching signal, a supercooling degree strengthening mode is switched, and the opening degree of an economizer branch electronic expansion valve is adjusted according to the deviation between the current supercooling degree and the target supercooling degree.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of heat pump control, and particularly relates to a low-temperature heat pump anti-liquid-impact and supercooling degree reinforcement control method based on dual-mode adaptive regulation. BACKGROUND

[0002] An air source heat pump running in an extremely low temperature environment (-30 ℃ to 5 ℃) faces the dual challenges of liquid refrigerant retention and system energy efficiency reduction. At the initial stage of starting, large-area liquid refrigerant accumulation may occur at the bottom of the gas-liquid separator and the evaporator pipeline, the circulating refrigerant amount decreases sharply, the suction liquid rate of the compressor rises, liquid impact is triggered, and the service life of the compressor is shortened. The common practice is to preheat by electric heating or fixed proportion bypass, but this kind of means not only consumes energy but also cannot identify the liquid cold accumulation degree in real time, resulting in insufficient protection or excessive preheating. After entering the normal running stage, the condensing pressure fluctuates greatly under low temperature conditions, and the throttling flash evaporation ratio increases. The traditional supercooling degree control based on fixed targets and single PID cannot maintain stability under rapid load changes, and the situation of insufficient supercooling degree and reduced COP often occurs. More complex is that liquid impact protection and supercooling adjustment are usually driven by independent logic, and when some actuators (electronic expansion valve, three-way valve, bypass pipeline, etc.) are cross-used, they restrict each other, and cannot balance between starting safety and running efficiency, which seriously limits the application and promotion of air source heat pumps in severe cold regions. SUMMARY

[0003] The purpose of the application is to design a low-temperature heat pump anti-liquid-impact and supercooling degree reinforcement control method based on dual-mode adaptive regulation, which can guarantee the safety of compressor starting and maintain high-efficiency heat exchange in the steady state, so as to shorten the preheating time, reduce energy consumption and improve the COP of low-temperature air source heat pumps in severe cold regions.

[0004] In order to achieve the above purpose, the application provides a low-temperature heat pump anti-liquid-impact and supercooling degree reinforcement control method based on dual-mode adaptive regulation, which comprises the following steps: monitoring the temperature at the bottom of the gas-liquid separator and the change rate of the temperature, and constructing a liquid impact risk index by a weighted synthesis method based on the difference between the temperature and a preset safety critical temperature, and the difference between the change rate and a preset minimum temperature rise rate; calculating the pulse power excitation strength based on the liquid impact risk index, combining a nonlinear risk amplification mechanism and a heat capacity correction factor, and dynamically selecting the number of opened injection channels and adjusting the pulse duty cycle of each channel to control the injection of high-temperature gaseous refrigerant into the bottom of the gas-liquid separator in a pulse mode to drive the evaporation of liquid refrigerant; calculating a liquid impact response decay factor, combining the temperature difference between the condenser and the gas-liquid separator, and the system heat exchange response rate, and generating a mode switching score, and when the mode switching score exceeds a mode switching threshold value and the temperature at the bottom of the gas-liquid separator reaches a safety lower limit, a mode switching signal is generated. According to the mode switching signal, a supercooling degree strengthening mode is switched to, and an opening degree of an economizer branch electronic expansion valve is adjusted according to a deviation of a current supercooling degree from a target supercooling degree, in combination with a ratio of a condensing pressure to a critical pressure, so that stable control of the supercooling degree is realized.

[0005] Further, the nonlinear risk amplification mechanism is realized by introducing a high-order nonlinear term of the liquid strike risk index, which enhances the response strength of the system in a high-risk interval.

[0006] Further, the heat capacity correction factor is calculated by monitoring the dynamic relationship between the heating input and the gas-liquid separator temperature rise response in a reverse deduction manner.

[0007] Further, the pulse power excitation intensity is based on the liquid strike risk index, specifically: when the liquid strike risk index is higher than a first risk threshold, a first frequency value is used; when the liquid strike risk index is between the first risk threshold and a second risk threshold, a second frequency value is used; and when the liquid strike risk index is lower than the second risk threshold, a third frequency value is used, wherein the first frequency value is greater than the second frequency value, and the second frequency value is greater than the third frequency value.

[0008] Further, the system heat exchange response rate is obtained by calculating the rate of change of the difference between the evaporator inlet temperature and the condenser outlet temperature with respect to time.

[0009] Further, the liquid strike response decay factor is calculated by the ratio of the current number of open jet channels to the maximum number of channels, and the ratio of the current duty cycle to the maximum duty cycle.

[0010] Further, the mode switching threshold value can be adaptively adjusted according to the real-time running state parameters and historical performance data of the system; the adaptive adjustment is specifically realized by the following way: based on the mode switching success rate and energy efficiency performance data of the system in historical operation, a threshold optimization model is established, the threshold optimization model takes the condensing pressure fluctuation range, the ambient temperature change rate and the system load change trend as input parameters, and outputs the optimal mode switching threshold value recommendation; the control system selects and applies the corresponding threshold value recommendation according to the similarity between the current operating environment and the historical data.

[0011] Further, the mode switching score is calculated by the following way: the liquid strike response decay factor, the ratio of the condenser and gas-liquid separator temperature difference to the reference temperature difference, and the difference between the system heat exchange response rate and the minimum threshold value are weighted and summed, wherein the difference between the system heat exchange response rate and the minimum threshold value is processed by the ReLU function, and only when the heat exchange rate exceeds the preset threshold value, the score is counted.

[0012] Further, the ratio of the condensing pressure to the critical pressure adopts a segmented suppression strategy, specifically including: when the condensing pressure is lower than a first pressure threshold, a first suppression coefficient is adopted; when the condensing pressure is between the first pressure threshold and a second pressure threshold, a second suppression coefficient is adopted; when the condensing pressure is higher than the second pressure threshold, a third suppression coefficient is adopted; wherein the first suppression coefficient is smaller than the second suppression coefficient, and the second suppression coefficient is smaller than the third suppression coefficient.

[0013] Further, when it is detected that the supercooling degree deviation is continuously lower than a set threshold for X sampling periods, the system automatically locks the current economizer opening, and the X is a preset value.

[0014] The beneficial technical effects of the present application are at least in the following points: To solve the above problems, the present application provides a low-temperature heat pump anti-liquid-impact and supercooling degree reinforcement control method based on dual-mode adaptive regulation, which realizes dynamic adjustment of the injection channel and duty cycle according to the risk level by using the bottom temperature of the gas separator and its temperature rise slope to construct a liquid impact risk index in real time, triggering pulse bypass heating before the formation of liquid impact risk, and introducing liquid heat capacity ratio correction, taking into account response speed and energy consumption. The process includes composite switching criteria of injection attenuation factor, condensing-gas separation temperature difference and heat transfer enhancement rate, and only when the liquid impact risk is removed and the system heat cycle has recovered, the supercooling enhancement is switched to, avoiding safety hazards caused by false switching. A supercooling degree closed-loop regulation formula with a condensing pressure suppression term is established to automatically limit the refrigerant distribution under high pressure while ensuring the target supercooling degree, preventing unstable conditions caused by over-regulation. Through the above three collaborative innovations, the present application realizes a continuous link of liquid impact prediction-dynamic intervention-mode switching-supercooling optimization, which not only ensures the safety of compressor startup, but also maintains efficient heat exchange in the steady state stage, shortens the preheating time of low-temperature air source heat pump in severe cold regions, reduces energy consumption and improves COP. BRIEF DESCRIPTION OF DRAWINGS

[0015] The present application is further described by the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the following drawings.

[0016] Figure 1 The present application is further described by the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the following drawings. DETAILED DESCRIPTION

[0017] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation on the present application.

[0018] In one or more embodiments, as shown in Figure 1 A low-temperature heat pump anti-liquid-impact and supercooling degree strengthening control method based on dual-mode adaptive regulation is disclosed, and the method comprises the following steps: S1: Monitor the temperature at the bottom of the gas-liquid separator and the change rate of the temperature, and based on the difference between the temperature and the preset safety critical temperature and the difference between the change rate and the preset minimum temperature rise rate, construct a liquid impact risk index by a weighted synthesis method; Specifically, the core goal of this step is to identify the thermal state of the refrigerant in the gas-liquid separator at the initial stage of the low-temperature heat pump startup, determine whether there is a risk of liquid refrigerant accumulation, and quantitatively describe the liquid impact trend. The accumulation of liquid refrigerant at the bottom of the gas separator is a common problem in the startup of a heat pump under low-temperature conditions, and its direct consequence is the liquid suction operation of the compressor, which leads to the risk of liquid impact. Traditional systems usually rely on timed preheating or fixed proportion bypass circuits to preheat the gas separator, but it is difficult to determine whether there is really a liquid cold accumulation situation in real time, and it is easy to have the problems of "insufficient preheating" or "excessive preheating", causing energy waste or protection failure. Therefore, a risk criterion that can describe the liquid accumulation trend in real time is needed.

[0019] This step directly uses two types of core sensing quantities at the initial running of the system as inputs. The first type is the temperature at the bottom of the gas-liquid separator , which is collected by an NTC thermistor sensor arranged at the bottom of the separator (the accuracy of this sensor is usually ±0.1℃, and the response time is <1s). This point is usually the position where liquid refrigerant is most likely to accumulate in the gas separator. The control system reads this temperature data every 2 seconds and stores it in a cache ring queue.

[0020] The second input is the change rate of the temperature at the bottom of the gas separator per unit time , which is calculated online by the system controller at runtime using a first-order difference method. The difference interval is a fixed period of seconds, and the difference calculation formula is as follows: ; Where is the current time point. This slope value is used to reflect the response speed of the bottom refrigerant to the change in heat. If the heating has been started but the temperature slope continues to approach zero, it means that the heat energy has not been able to effectively drive the phase change evaporation, and there is a problem of refrigerant accumulation without evaporation.

[0021] The above two original variables together constitute the input basis for the liquid impact risk modeling. In order to enable the system to use a single control quantity to drive the subsequent strategy in the control logic, this step introduces a comprehensive liquid impact risk index , and the calculation formula is as follows: ; The formula consists of two weighted terms: the first term measures whether the current gas separator temperature is below a set safety threshold , typically set at 5℃, when the gas separator temperature is below this value, it indicates that the refrigerant is still in liquid state or has not evaporated sufficiently, here is the "liquid knock risk detection threshold", which determines whether the gas separator bottom temperature is still in the low-temperature liquid region, the physical meaning here is to trigger protection; when the gas-liquid separator bottom temperature is lower than , it can be determined that the separator is still in the low-temperature liquid region of the refrigerant or just enters the evaporation edge region, the liquid has not been fully vaporized, the compressor suction risk is high, the controller must immediately enter the liquid knock protection mode (turn on the pulse bypass heating, limit the compressor frequency, etc.). The second term reflects whether the temperature rise rate is lower than the minimum expected rate , usually set at , this rate value comes from experimental calibration, indicating the minimum evaporation response speed that the gas separator should achieve under normal bypass injection state.

[0022] The two indicators are constructed into a single-sided function by the max function to avoid misjudgment of normal working conditions with high temperature or rapid temperature rise. The weighting coefficients , are set to 0.6 and 0.4 by default in the factory setting, and can be adjusted slightly in extremely low-temperature areas. The meaning is that if one item has reflected a significant risk, the overall index can be raised to drive the system into protection mode in advance.

[0023] Specifically, when the gas separator bottom temperature is only -8.5℃ and the temperature rise slope is 0.05℃ / s, then: ; The system normalizes the value to the interval (e.g. with as the maximum threshold), and the final control input value is , indicating a serious liquid cooling risk, which should be immediately activated in the next step.

[0024] S2: Based on the liquid knock risk index, combined with a nonlinear risk amplification mechanism and a heat capacity correction factor, calculate the pulse power excitation intensity, and dynamically select the number of open injection channels and adjust the pulse duty cycle of each channel to control the injection of high-temperature gaseous refrigerant into the bottom of the gas-liquid separator in a pulse manner, driving the evaporation of liquid refrigerant; Specifically, the step aims to quickly drive local refrigerant vaporization through structured, energy-saving, and high-response intervention means after identifying the risk of liquid refrigerant accumulation in the gas-liquid separator, thereby avoiding the risk of liquid refrigerant suction by the compressor during the startup phase. Unlike traditional methods, this solution not only determines whether to open the bypass injection based on the liquid knock risk value, but also introduces dynamic adjustment terms and nonlinear correction quantities in the channel cascade strategy, pulse excitation mechanism, and system response terms, enabling the control system to quickly break through the thermal resistance barrier of the liquid cooling accumulation point with less energy consumption, improving overall startup safety and efficiency.

[0025] Unlike traditional fixed rhythm injection, this step designs a dynamic regulation mechanism that combines a nonlinear risk amplification term and a "thermal capacity resistance correction factor" during the startup phase, and proposes the following control formula: ; Where: is the pulse power excitation intensity control factor (used to determine the duty cycle and injection energy of each channel); is the liquid knock risk index, from step one; is the linear amplification weight, with a default value of 0.8; is the nonlinear response gain factor, used to enhance the response sensitivity of high-risk sections, typically set to 0.6; is the current estimated thermal capacity of the gas separator, calculated by monitoring the temperature rise rate under unit heating input; is the reference thermal capacity under standard conditions (calibration value); is the thermal capacity correction weight factor, generally set to 1.0-1.5, used to increase the pulse intensity in high thermal capacity situations.

[0026] In this formula, the term as a nonlinear gain mechanism can sharply increase the response intensity when the risk value approaches 1, avoiding the mismatch between "slow response and high risk"; secondly, the thermal capacity ratio term by evaluating the system refrigerant thermal resistance level, automatically adjusts the injection intensity, solving the low energy efficiency problem of traditional solutions in different gas separation structures and thermal capacity characteristics.

[0027] In specific implementation, the system maps to the following control strategy: Channel selection: if , enable 1 channel; , enable 2 channels; , open 3 channels.

[0028] Pulse duty cycle adjustment: map to the pulse duty cycle of each channel (0.2-0.8), for example, by linear normalization: ; The controller periodically opens the electromagnetic valve at a pulse frequency of 1 Hz (which can be dynamically adjusted) to inject high-temperature gaseous refrigerant into the bottom of the gas separator through a directional nozzle.

[0029] Specifically, during a certain low-temperature startup phase, the system monitors: ; ; then: ; The final duty cycle is , activating 3 channels. The injection module will enter a high-intensity heating state, rapidly driving the local evaporation of refrigerant in the gas separator and reducing the risk of liquid impact.

[0030] S3: Calculate the liquid impact response decay factor, and combine the temperature difference between the condenser and the gas-liquid separator, the system heat exchange response rate, to generate a mode switching score. When the mode switching score exceeds the mode switching threshold and the gas-liquid separator temperature reaches the lower limit of safety, a mode switching signal is generated. Specifically, the step constructs a criterion model highly adapted to the working condition of the low-temperature heat pump, integrates three types of core signals: execution state, thermal state, and energy efficiency trend, to determine whether the system meets the conditions of "liquid impact risk has been alleviated and has the potential for supercooling enhancement", and then triggers the subsequent control process.

[0031] First, build the basic state factor: ; This term represents the "decay degree" of the liquid impact response strength. The higher the value, the weaker the current protection, indicating that the system is in the response end period, creating a premise for switching. Among them: represents the number of bypass injection channels that are currently actually in the open state; is the maximum duty cycle upper limit allowed by the single-channel pulse controller, representing the longest opening ratio of the electromagnetic valve per second under the 1 Hz reference frequency; Further, add the working condition feedback index to the main criterion: The temperature difference between the condenser outlet and the bottom of the gas separator ; wherein, is the temperature of the condenser outlet; is the total heat exchange response capability change rate of the system after the compressor starts , wherein is the evaporator inlet temperature.

[0032] The complete switching criterion is finally constructed as follows: ; wherein: is the calibrated temperature difference (e.g. 15°C); is the empirical adjustment weight, typical value is 0.4, 0.3; is the minimum threshold of heat transfer enhancement (e.g. 1.0°C / min); indicates that only when the heat transfer rate is significantly enhanced, the score is counted, to prevent false switching caused by slow heat transfer disturbance.

[0033] The system refreshes all input quantities every 10 seconds, calculates , if the following conditions are met: ; then trigger mode switching; wherein is the switching threshold (the standard value under normal operating conditions is recommended to be 0.9), is the gas temperature safety limit (e.g. 30°C), here is the "switching safety temperature limit", only when the gas separator temperature has risen enough to prove that the refrigerant is basically vaporized and the risk of liquid hammer is eliminated, the system is allowed to enter the supercooling enhancement mode, the physical meaning here is to remove the protection, only when rises to and remains stable, it is considered that the refrigerant has obtained sufficient superheat, all liquid is vaporized and the oil circuit is unobstructed, at this time the protection is allowed to be removed and switched to the supercooling enhancement mode to improve system efficiency. Taking the commonly used R-410A for air source heat pump in northern China as an example, at 0.4 MPa (gauge pressure, ≈4 barA), its saturation temperature is about -20°C; when the temperature at the bottom of the gas separator rises to about 5°C, it only indicates that it is close to the liquid-gas equilibrium edge, and there may still be liquid residue locally, which needs to trigger protection immediately. On the contrary, if the temperature at this point is stable above 30°C, the system (under the corresponding operating conditions) is far from the saturation curve; in addition, R-410A has good mutual solubility and flowability with POE oil in the operating range of about 1.9-2.0 MPa, which is beneficial to oil return and inlet air drying, so it can be used as the safety lower limit for removing protection and entering performance optimization. If R-32 with a higher saturation curve is used, the two thresholds can be moved up as a whole, but a safety margin of 20-25 K between them is recommended to ensure that it is triggered early enough and avoid exiting too early. When the conditions are met, the following flag is output: , indicating that it can be switched to the supercooling enhancement mode; otherwise, maintain , the system continues to perform liquid hammer protection operation.

[0034] For example, the state of the system at a certain time is as follows: , ; , ; , ; then: ; , ; ; then: ; If set , the recommended switching threshold in the general operating scenario, at this time , so the system remains in the liquid-impact protection mode, and switches to the performance-enhanced path to execute the supercooling degree control strategy after the next cycle meets the conditions; If set , the recommended switching threshold in the ultra-low temperature or rapid load fluctuation working condition, at this time the switching condition is met, and the system will enter the performance-enhanced path to execute the supercooling degree control strategy.

[0035] S4: Switch to the supercooling degree enhancement mode according to the mode switching signal, adjust the opening degree of the economizer branch electronic expansion valve according to the deviation of the current supercooling degree and the target supercooling degree, and combine the ratio of the condensing pressure and the critical pressure to realize stable control of the supercooling degree.

[0036] Specifically, the core task of this step is: after confirming that it can switch from the liquid-impact protection mode to the supercooling degree enhancement mode (i.e. ) in the previous step, the activation and dynamic control of the supercooling path are specifically executed to ensure that the system realizes efficient heat exchange and rapid supercooling in a low-temperature environment while ensuring system stability and safety.

[0037] When , the system starts to gradually activate the supercooling enhancement loop. In this embodiment, the supercooling loop controls the bypass refrigerant flow by an electronic expansion valve. The target is to gradually control the supercooling degree to the set target (recommended 10℃) and maintain system stability.

[0038] First, define the current supercooling degree difference value: ; Among them: is the real-time supercooling degree measured value; if , it indicates that the supercooling needs to be enhanced, and the system gradually increases the opening degree of the economizer branch .

[0039] To ensure the adjustment response is not affected by the large fluctuations in condensing pressure, this solution introduces a pressure-related compensation inhibition term, and the final control formula is: ; Wherein: is the updated economizer branch electronic expansion valve opening; is the current opening, saved by the internal state of the controller; is the proportional gain term (such as 0.08 / ℃); is the condensing pressure penalty coefficient (such as 0.1); is the critical pressure (system design value, such as 2.5 MPa); is the condenser outlet side high pressure pipeline pressure; Specifically, the current (indicates an opening of 40%); ; MPa, MPa; Then: ; The controller will adjust the valve to an opening of 55.2% with the smallest step (such as 2%), and continue to monitor whether it is close to the target.

[0040] If for three consecutive sampling periods (such as 30 seconds), it is considered that the supercooling degree has stabilized, and the controller will lock the current , enter the steady state mode, and wait for the next round of heat load change.

[0041] The embodiment of the application also provides a low-temperature heat pump anti-liquid-splashing and supercooling degree strengthening control device based on a dual-mode adaptive regulation, which comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements steps in the above-mentioned low-temperature heat pump anti-liquid-splashing and supercooling degree strengthening control method embodiment based on a dual-mode adaptive regulation, for example, steps S1-S6 in the above-mentioned embodiment. Figure 1 Or, the processor implements the functions of the modules in each of the above-mentioned system embodiments when executing the computer program.

[0042] Illustratively, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the application. The one or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the low-temperature heat pump anti-liquid-splashing and supercooling degree strengthening control device based on a dual-mode adaptive regulation.

[0043] The low-temperature heat pump liquid-impact-prevention and supercooling-enhancement control device based on dual-mode adaptive regulation can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The low-temperature heat pump liquid-impact-prevention and supercooling-enhancement control device based on dual-mode adaptive regulation can include, but is not limited to, a processor, a memory, and the like. Those skilled in the art can understand that the low-temperature heat pump liquid-impact-prevention and supercooling-enhancement control device based on dual-mode adaptive regulation can also include an input / output device, a network access device, a bus, and the like.

[0044] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASAC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. The general-purpose processor can be a microprocessor or can also be any conventional processor, and the like. The processor is a control center of the low-temperature heat pump liquid-impact-prevention and supercooling-enhancement control device based on dual-mode adaptive regulation, and connects each part of the low-temperature heat pump liquid-impact-prevention and supercooling-enhancement control device based on dual-mode adaptive regulation through various interfaces and lines.

[0045] The memory can be used to store the computer programs and / or modules. The processor realizes various functions of the low-temperature heat pump liquid-impact-prevention and supercooling-enhancement control device based on dual-mode adaptive regulation by running or executing the computer programs and / or modules stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area. The program storage area can store an operating system, at least one application required by a function, and the like. The data storage area can store data created according to the running of the air conditioner controller, and the like. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital card (SD), a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0046] If the low-temperature heat pump liquid-impact-preventing and supercooling-enhancing control device integrated based on the dual-mode adaptive regulation is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0047] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing relevant hardware. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned various method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0048] The above-mentioned is the preferred embodiment of the present application. It should be noted that those of ordinary skill in the art can make several improvements and refinements without departing from the principles of the present application. These improvements and refinements are also considered within the protection scope of the present application.

Claims

1. A low-temperature heat pump anti-liquid-splashing and supercooling degree strengthening control method based on dual-mode adaptive regulation, characterized in that, The method comprises: Monitoring the temperature at the bottom of the gas-liquid separator and the rate of change of the temperature, and constructing a liquid impact risk index by a weighted combination method based on the difference between the temperature and a preset safety critical temperature and the difference between the rate of change and a preset minimum temperature rise rate; Based on the liquid impact risk index, the pulse power excitation strength is calculated in combination with a nonlinear risk amplification mechanism and a heat capacity correction factor, and the number of open injection channels and the pulse duty cycle of each channel are dynamically selected accordingly to control the injection of high-temperature gaseous refrigerant into the bottom of the gas-liquid separator in a pulse mode to drive the evaporation of liquid refrigerant; A liquid impact response decay factor is calculated, and a mode switching score is generated in combination with the temperature difference between the condenser and the gas-liquid separator and the system heat exchange response rate, and a mode switching signal is generated when the mode switching score exceeds a mode switching threshold and the temperature of the gas-liquid separator reaches a lower safety limit; According to the mode switching signal, the system switches to a supercooling enhancement mode, adjusts the opening of the economizer branch electronic expansion valve according to the deviation of the current supercooling degree from the target supercooling degree, and combines the ratio of the condensing pressure to the critical pressure to realize stable control of the supercooling degree.

2. The low-temperature heat pump anti-liquid-pounding and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The nonlinear risk amplification mechanism is realized by introducing a high-order nonlinear term of the liquid impact risk index, which enhances the response strength of the system in the high-risk interval.

3. The low-temperature heat pump anti-liquid-penetration and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The heat capacity correction factor is calculated by monitoring the dynamic relationship between the heating input and the temperature rise response of the gas-liquid separator in a reverse deduction manner.

4. The low-temperature heat pump anti-liquid-penetration and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The pulse power excitation strength is obtained based on the liquid impact risk index, specifically: when the liquid impact risk index is higher than a first risk threshold, a first frequency value is used; when the liquid impact risk index is between the first risk threshold and a second risk threshold, a second frequency value is used; and when the liquid impact risk index is lower than the second risk threshold, a third frequency value is used, wherein the first frequency value is greater than the second frequency value, and the second frequency value is greater than the third frequency value.

5. The low-temperature heat pump anti-liquid-penetration and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The system heat exchange response rate is obtained by calculating the rate of change of the difference between the evaporator inlet temperature and the condenser outlet temperature over time.

6. The low-temperature heat pump anti-liquid-spraying and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The liquid impact response decay factor is calculated by the ratio of the number of currently open injection channels to the maximum number of channels and the ratio of the current duty cycle to the maximum duty cycle.

7. The low-temperature heat pump anti-liquid-pounding and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The mode switching threshold is adaptively adjusted according to the real-time running state parameters and historical performance data of the system; the adaptive adjustment is specifically realized by the following way: based on the mode switching success rate and energy efficiency performance data of the system in historical operation, a threshold optimization model is established, which takes the condensing pressure fluctuation range, the ambient temperature change rate and the system load change trend as input parameters, and outputs the optimal mode switching threshold recommendation value; The control system selects and applies the corresponding threshold recommendation value according to the similarity of the current operating environment and historical data.

8. The low-temperature heat pump anti-liquid-penetration and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The mode switching score is calculated by weighted sum of the liquid slug response decay factor, the ratio of the condenser to the gas-liquid separator temperature difference to a reference temperature difference, and the difference between the system heat exchange response rate and a minimum threshold value, wherein the difference between the system heat exchange response rate and the minimum threshold value is processed by a ReLU function and only when the heat exchange rate exceeds a preset threshold value is the score counted.

9. The low-temperature heat pump anti-liquid-penetration and supercooling enhancement control method based on dual-mode adaptive regulation according to claim 1, characterized in that, The ratio of the condensing pressure to the critical pressure adopts a segmented suppression strategy, specifically including: when the condensing pressure is lower than a first pressure threshold, a first suppression coefficient is adopted; when the condensing pressure is between the first pressure threshold and a second pressure threshold, a second suppression coefficient is adopted; when the condensing pressure is higher than the second pressure threshold, a third suppression coefficient is adopted; wherein the first suppression coefficient is less than the second suppression coefficient, and the second suppression coefficient is less than the third suppression coefficient.

10. The method of claim 1, wherein the method is characterized by, When it is detected that the supercooling degree deviation is continuously lower than a set threshold value for X sampling periods, the system automatically locks the current economizer opening, and X is a preset value.

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