A method for rapid oil return in a heat pump system

Abstract

This invention provides a rapid oil return method for a heat pump system. The method includes: before starting the compressor, determining whether refrigerant deposits exist based on the ambient temperature and downtime; if refrigerant deposits are present, activating the auxiliary electronic expansion valve control program; if no refrigerant deposits are present, starting the heat pump according to the normal procedure; activating the auxiliary electronic expansion valve control program, comparing the exhaust superheat with a monitoring benchmark threshold to confirm whether control is based on exhaust superheat or injection superheat; simultaneously comparing the exhaust superheat with multiple pressure thresholds and the injection superheat with multiple temperature thresholds to confirm the opening degree of the auxiliary electronic expansion valve; confirming that the compressor temperature, pressure, and exhaust superheat are within the normal range, confirming stable refrigerant flow rate, unlocking the auxiliary electronic expansion valve control program, exiting the rapid oil return mode, and restoring the heat pump to its automatic control mode. This invention ensures reliable compressor operation and significantly improves product reliability.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for heat pumps, and in particular to a rapid oil return method for a heat pump system. Background Technology

[0002] The heat pump industry is currently in a period of rapid growth. Air source heat pump products are popular because they have multiple functions such as cooling, heating and hot water production. The operating temperature range of their heating mode can reach -35℃ to 45℃. Generally, the indoor temperature is always maintained at a high value. In the low temperature environment of the outdoors, especially in cold regions, the indoor medium is a high temperature heat source and the outdoor medium is a low temperature heat source. Due to the driving force of the temperature difference between indoor and outdoor, when the unit is shut down for a long time, the refrigerant in the unit system gradually migrates from the high temperature heat source side to the low temperature heat source side. Finally, a large amount of refrigerant is deposited in the compressor refrigeration oil pool in liquid form, which causes the following problems: (1) The liquid refrigerant deposited in the compressor oil pool will release refrigeration oil, which makes the lubrication characteristics of the refrigeration oil worse, and the compressor is prone to wear or even damage when it starts up; (2) When the compressor starts up again, the oil temperature gradually rises, causing a large amount of liquid refrigerant deposited in the oil pool to evaporate and boil, and a large amount of refrigeration oil in the compressor oil pool is carried away to the system. This causes the compressor to run without oil for a period of time, resulting in abnormal wear of the operating parts inside the compressor and damage and scrapping.

[0003] Prior art, application number CN202310858806.3, discloses a high-efficiency oil return gas-liquid separator and a refrigeration / heat pump system, comprising a gas-liquid separator body, an oil return unit, and an ejector tube. The oil return unit's inlet is connected to the oil return port via an oil supply pipe, which is equipped with a flow control valve. The oil supply pipe and the oil return unit's inlet are perpendicular to each other in the vertical direction. The oil return unit's outlet is connected to the ejector fluid inlet of the ejector tube, and the other two ports of the ejector tube are connected to the outlet pipe and the compressor's return pipe, respectively. Although the gas-liquid separator has a simple structure and can conveniently and effectively control the lubricating oil circulation volume, while improving the purity of the returned oil, preventing liquid slugging during compressor startup, increasing the compressor's return gas superheat, and improving the performance, stability, and heat exchange efficiency of the refrigeration / heat pump system using the gas-liquid separator, it lacks the ability to determine the type of refrigeration oil used for lubrication inside the compressor. This reduces the reliability of the compressor's operation to some extent and is not conducive to effectively improving the efficiency of heat pump cooling or heating.

[0004] Prior art 2, application number: CN202311480730.1, discloses a gas-liquid separator and a heat pump unit, including a housing and a return gas pipe. The return gas pipe is disposed inside the housing and has a first oil return port and a second oil return port. The first oil return port is located at the bottom of the housing, and the second oil return port is located at the liquid surface inside the housing, and the second oil return port can move with changes in the liquid level. The gas-liquid separator and heat pump unit, by setting the first and second oil return ports on the return gas pipe, ensures normal oil return by placing the first oil return port at the bottom of the gas-liquid separator, guaranteeing that the compressor always receives a portion of refrigerant oil to ensure normal compressor operation and reliable oil return under normal operating conditions. Then, by placing the second oil return port at the liquid surface, it guides the refrigerant oil above the liquid refrigerant into the compressor. While this increases the oil supply to the compressor and effectively ensures reliable oil supply, it lacks the ability to detect refrigerant deposits, resulting in poor lubrication characteristics of the refrigerant oil and making the compressor prone to wear or even damage during startup.

[0005] Existing technology three, application number: CN202310652419.4gk, discloses a gas replenishment and oil return device for a static start-up ultra-low temperature heat pump system and its operating method. The heat pump system includes a compressor. The high-pressure outlet of the compressor is connected to the first port of a solenoid four-way valve. The second port of the solenoid four-way valve is connected to the first refrigerant inlet of a refrigerant-side heat exchanger. The first refrigerant outlet of the refrigerant-side heat exchanger is connected to the second refrigerant inlet of the refrigerant-side heat exchanger. The second refrigerant outlet of the refrigerant-side heat exchanger is connected to the third port of the solenoid four-way valve. The fourth port of the solenoid four-way valve is connected to the low-pressure inlet of the compressor. One end of a bypass solenoid valve electrically connected to a central controller is connected to the high-pressure outlet of the compressor, and the other end is connected to the low-pressure inlet of the compressor. The central controller controls the opening and closing of the bypass solenoid valve based on the low-pressure value. Although this increases the reliability of the compressor operation and the service life of the heat pump system, its structure is relatively simple and lacks intelligent control equipment, resulting in slow pressure regulation speed and low efficiency.

[0006] Current technologies 1, 2, and 3 suffer from several drawbacks. Firstly, during prolonged shutdowns, a large amount of liquid refrigerant deposits in the compressor oil sump, diluting the refrigeration oil and impairing its lubrication properties. This leads to wear and even damage during compressor startup. Secondly, upon restarting, a significant amount of refrigeration oil is carried away from the compressor oil sump into the system, resulting in a period of oil shortage operation and causing abnormal wear and damage to internal compressor components. Therefore, this invention provides a rapid oil return method for heat pump systems. By electronically detecting refrigerant deposits during startup, the method controls the auxiliary circuit electronic expansion valve to rapidly return the large amount of oil that has leaked from the compressor during the refrigerant deposit startup phase to the compressor. This ensures that the compressor's internal components are always adequately lubricated with refrigeration oil, guaranteeing reliable compressor operation. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a rapid oil return method for a heat pump system, comprising the following steps:

[0008] Before the compressor starts, the ambient temperature and downtime are obtained, and the presence of refrigerant deposits is determined based on the ambient temperature and downtime. If refrigerant deposits are present, the auxiliary circuit electronic expansion valve control program is activated; if no refrigerant deposits are present, the heat pump is started according to the normal procedure.

[0009] The auxiliary electronic expansion valve control program is started to compare the exhaust superheat with the monitoring benchmark threshold to confirm whether control is performed according to exhaust superheat or injection superheat. At the same time, the opening degree of the auxiliary electronic expansion valve is confirmed by comparing the exhaust superheat with multiple exhaust superheat thresholds and the injection superheat with multiple temperature thresholds.

[0010] Confirm that the compressor temperature, pressure, and discharge superheat are within the normal range, confirm that the refrigerant flow rate is stable, unlock the auxiliary circuit electronic expansion valve control program, exit the rapid oil return mode, and restore the heat pump to the automatic control mode.

[0011] Optionally, determining whether refrigerant deposition occurs based on ambient temperature and downtime includes the following steps:

[0012] The current ambient temperature of the compressor area is collected by an ambient temperature sensor, and the compressor downtime is monitored and recorded in real time from the heat pump system. The acquired ambient temperature and downtime are integrated to form a dataset.

[0013] A refrigerant deposition detection model is constructed and trained using multi-dimensional features such as ambient temperature and downtime to identify potential refrigerant deposition patterns. The model outputs a probability value indicating the presence of refrigerant deposition. When the probability value exceeds a detection threshold, refrigerant deposition is considered to be present.

[0014] Depending on whether refrigerant deposits are present, determine whether to activate the auxiliary circuit electronic expansion valve control program or start the heat pump according to the normal program. If refrigerant deposits are present, activate the auxiliary circuit electronic expansion valve control program, and the heat pump will be stopped during the normal program.

[0015] Optionally, the process of creating a dataset includes the following steps:

[0016] A short-time polling strategy is used to acquire temperature readings from temperature sensing devices. Multiple temperature measurement data are acquired within a time interval to form a temperature fluctuation spectrum. A timer is used to record the start-up and stop times of the compressor in real time. The compressor status changes are automatically sensed. When the compressor stops, the timer starts. The records include the duration of continuous compressor stop and the total stop time.

[0017] The collected ambient temperature and downtime data are integrated and normalized in real time to form a multidimensional dataset. Feature extraction is performed on the temperature and time data to generate additional features, including the temperature change rate, to show abrupt temperature changes and downtime patterns, and to identify which patterns are related to refrigerant deposition.

[0018] The integrated and normalized dataset is stored in the database; version control of the dataset is also implemented, saving different versions of the data for different operating cycles.

[0019] Optionally, the process of constructing a refrigerant deposition judgment model includes the following steps:

[0020] From the dataset, we extract the features of factors that influence the addition of refrigerant deposition, including the rate of temperature change, cumulative downtime, and stability index; we then divide the dataset into training, validation, and test sets.

[0021] Random forest was applied to the training set to train the cold medium deposition judgment model. The optimization process used cross-validation to adjust the hyperparameters.

[0022] The trained refrigerant deposition detection model was evaluated using a validation set. Evaluation metrics included accuracy, precision, and recall. The model output the probability value of refrigerant deposition. The validated refrigerant deposition detection model was then embedded into a real-time monitoring system and set to automated operation mode to receive and analyze ambient temperature and downtime data in real time.

[0023] Optionally, the setup process for the auxiliary circuit electronic expansion valve control program includes the following steps:

[0024] Design a multi-level control program that includes three levels: data analysis, decision execution, and operation feedback. The first level is responsible for real-time data acquisition and status assessment, the second level is responsible for judgment logic and control decisions, and the last level is responsible for execution and feedback.

[0025] Using a trained refrigerant deposition detection model, the system analyzes ambient temperature and downtime to output a probability value indicating the presence of refrigerant deposition. When this probability value exceeds a set threshold, a refrigerant deposition indicator signal is immediately triggered. Upon detecting refrigerant deposition, the system immediately switches operating modes according to pre-defined priority rules, adjusting the opening degree of the auxiliary electronic expansion valve to meet refrigerant flow requirements. Simultaneously, it automatically sends a stop heat pump command, cutting off the heat pump startup procedure.

[0026] After receiving a signal indicating the presence of refrigerant deposits, a stop signal is sent to the heat pump control loop via a programmable logic controller. A status feedback loop is established to monitor the heat pump output status in real time through sensors, ensuring that the stop command is effectively executed. If the feedback signal indicates that the heat pump is still in the start-up state, a fault handling mechanism will be activated to resend the stop command and troubleshoot the fault.

[0027] Optionally, the process of controlling the exhaust superheat or injection superheat includes the following steps:

[0028] The auxiliary electronic expansion valve opens to the preset initial opening degree and maintains this state;

[0029] After completing the initial opening setting, the exhaust superheat is monitored and adjusted in real time. The opening of the auxiliary electronic expansion valve is adjusted according to the set conditions based on different superheat ranges.

[0030] When the compressor is turned on and the exhaust superheat is detected to exceed the set monitoring benchmark threshold for the first time, the auxiliary electronic expansion valve exits the control mode of the refrigerant deposition start-up stage and enters the regulation of exhaust or injection superheat.

[0031] Optionally, the process of obtaining the exhaust superheat includes the following steps:

[0032] The actual temperature at the compressor's exhaust end is monitored in real time using an exhaust temperature sensor; simultaneously, a high-pressure sensor monitors the high-pressure value.

[0033] Based on the known high pressure value, consult the refrigerant's property table, and use the relationship between the refrigerant's saturated vapor pressure and corresponding temperature to calculate the saturation temperature corresponding to the pressure.

[0034] The difference between the actual temperature and the saturation temperature is used to obtain the exhaust superheat, which determines the safety of the compressor's exhaust state.

[0035] Optionally, the process of obtaining the superheat from the jet includes the following steps:

[0036] The temperature at the auxiliary output end is monitored in real time using an auxiliary output temperature sensor; at the same time, the temperature at the auxiliary inlet end is monitored using an auxiliary inlet temperature sensor.

[0037] By comparing the outlet temperature and the inlet temperature, the temperature difference, i.e. the injection superheat, is calculated. This represents the temperature change of the refrigerant from the inlet end to the outlet end after it passes through the system, reflecting the degree of refrigerant superheat.

[0038] Based on the result of the injection superheat, it is compared with the set threshold. If the calculated injection superheat exceeds the preset value, the automatic adjustment mechanism will be activated to adjust the opening of the auxiliary electronic expansion valve through real-time feedback.

[0039] Optionally, the process of unlocking the auxiliary circuit electronic expansion valve control program includes the following steps:

[0040] The compressor's temperature and pressure are comprehensively monitored, including confirming whether the compressor's exhaust superheat is within the safe threshold; the refrigerant flow rate is monitored in real time using a flow sensor, and if the flow rate is stable and within the preset range, the next step is carried out.

[0041] Based on real-time monitoring results, the opening adjustment strategy of the auxiliary electronic expansion valve is determined, and the opening setting parameters are obtained; the unlocking procedure is automatically executed to switch the auxiliary electronic expansion valve control program from the locked state to the unlocked state.

[0042] Once unlocked, it automatically switches to the heat pump's automatic control mode; the opening of the auxiliary electronic expansion valve will automatically adjust according to changes in pressure, temperature, and demand.

[0043] Optionally, the process of obtaining the opening adjustment strategy of the auxiliary electronic expansion valve includes the following steps:

[0044] Data from multiple sensors is collected, including compressor temperature, pressure, discharge superheat, and refrigerant flow rate. The collected data is cleaned to remove outliers and noise. Key variables affecting the opening setting are identified, including ambient temperature, system pressure, discharge superheat, and refrigerant flow rate.

[0045] Based on key variables monitored in real time, set objective functions to maximize cooling efficiency, minimize energy consumption, or minimize exhaust superheat; use acquired data and historical operating patterns to predict demand and adjust the opening degree.

[0046] Based on the obtained opening setting parameters, specific control commands are generated and sent to the auxiliary electronic expansion valve; after the opening adjustment is executed and the execution is obtained, feedback is provided on whether the setting has achieved the expected effect, thus forming a closed-loop control.

[0047] This invention relates to a refrigerant deposition detection and startup control program. By acquiring ambient temperature and downtime, it can assess whether refrigerant deposition exists in the system. If refrigerant deposition is detected, the auxiliary electronic expansion valve control program is activated. The system determines whether to start the heat pump system normally based on the refrigerant state. If refrigerant deposition is present, additional control measures are taken to prevent potential malfunctions after startup. The significance is that by confirming the refrigerant state before compressor startup, liquid slugging caused by refrigerant deposition can be prevented, thus protecting the compressor and system components. It also ensures that the heat pump starts under stable conditions, reducing maintenance and downtime caused by refrigerant issues and improving equipment reliability. The control program's activation and threshold comparison involves activating the auxiliary electronic expansion valve control program to monitor exhaust superheat and injection superheat in real time and compare them with reference thresholds. It checks whether the exhaust superheat and injection superheat are within preset exhaust superheat threshold ranges and set temperature threshold ranges, and adjusts the opening of the auxiliary electronic expansion valve based on the comparison results to achieve optimal refrigerant flow and system operation. Significance Achieved: Through precise adjustment, the heat pump can maintain good performance during the rapid oil return phase, achieving rapid and effective refrigerant recirculation and ensuring efficient system operation. Optimized refrigerant flow helps improve the heat pump's coefficient of performance (COP), reducing energy consumption and thus improving overall economy. Confirming the heat pump status and resuming automatic control involves verifying that key parameters such as compressor temperature, pressure, and exhaust superheat are within normal ranges, and confirming the stability of the refrigerant flow rate. After confirming the heat pump status is correct, the auxiliary circuit electronic expansion valve control program is unlocked, exiting the rapid oil return mode and restoring the normal heat pump automatic control mode. Significance Achieved: This ensures that all parameter settings are in a safe and stable state before entering the normal control mode, thereby avoiding instability and potential malfunctions during operation. It achieves a seamless switch between rapid oil return and normal operation, enabling the heat pump system to maintain good continuity during operation and improving working efficiency.

[0048] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0049] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0050] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0051] Figure 1This is a flowchart of the rapid oil return method for the heat pump system in Embodiment 1 of the present invention;

[0052] Figure 2 This is a diagram illustrating the process of determining whether refrigerant deposition exists based on ambient temperature and downtime in Embodiment 2 of the present invention.

[0053] Figure 3 This is a diagram illustrating the process of forming a dataset in Embodiment 3 of the present invention;

[0054] Figure 4 This is a process diagram of constructing the refrigerant deposition judgment model in Embodiment 4 of the present invention;

[0055] Figure 5 This is a diagram illustrating the setup process of the auxiliary electronic expansion valve control program in Embodiment 5 of the present invention;

[0056] Figure 6 This is a process diagram illustrating the control based on exhaust superheat or injection superheat in Embodiment 6 of the present invention.

[0057] Figure 7 This is a diagram illustrating the process of obtaining exhaust superheat in Embodiment 7 of the present invention;

[0058] Figure 8 This is a diagram illustrating the process of obtaining the superheat of the spray in Embodiment 8 of the present invention;

[0059] Figure 9 This is a flowchart of the control program for unlocking the auxiliary electronic expansion valve in Embodiment 9 of the present invention;

[0060] Figure 10 This is a diagram illustrating the process of obtaining the opening adjustment strategy of the auxiliary electronic expansion valve in Embodiment 10 of the present invention;

[0061] Figure 11 This is a block diagram of the heat pump system in Embodiment 11 of the present invention. Detailed Implementation

[0062] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0063] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0064] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0065] Example 1: As Figure 1 As shown, this embodiment of the invention provides a rapid oil return method for a heat pump system, comprising the following steps:

[0066] S100: Before the compressor starts, the ambient temperature and downtime are obtained, and the presence of refrigerant deposits is determined based on the ambient temperature and downtime. If refrigerant deposits are present, the auxiliary circuit electronic expansion valve control program is activated. If no refrigerant deposits are present, the heat pump is started according to the normal program.

[0067] S200: Start the auxiliary electronic expansion valve control program, compare the exhaust superheat with the monitoring reference threshold, and confirm whether control is performed according to exhaust superheat or injection superheat; at the same time, compare the exhaust superheat with multiple exhaust superheat thresholds and the injection superheat with multiple temperature thresholds to confirm the opening degree of the auxiliary electronic expansion valve.

[0068] S300: Confirm that the compressor temperature, pressure and discharge superheat are within the normal range, confirm that the refrigerant flow rate is stable, unlock the auxiliary circuit electronic expansion valve control program, exit the rapid oil return mode, and restore the heat pump's automatic control mode.

[0069] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, before the compressor starts, the ambient temperature and shutdown time are obtained, and it is determined whether there is refrigerant deposition based on the ambient temperature and shutdown time. If refrigerant deposition is present, the auxiliary electronic expansion valve control program is activated; if no refrigerant deposition is present, the heat pump is started according to the normal procedure. Secondly, the auxiliary electronic expansion valve control program is activated to compare the exhaust superheat with the monitoring benchmark threshold to confirm whether control is performed according to exhaust superheat or injection superheat. At the same time, the opening degree of the auxiliary electronic expansion valve is confirmed by comparing the exhaust superheat with multiple exhaust superheat thresholds and the injection superheat with multiple temperature thresholds. Finally, the compressor temperature, pressure, and exhaust superheat are confirmed to be within the normal range, the refrigerant flow rate is confirmed to be stable, the auxiliary electronic expansion valve control program is unlocked, the rapid oil return mode is exited, and the automatic control mode of the heat pump is restored. Step S100 of the above scheme determines refrigerant deposition and starts the control program. By acquiring the ambient temperature and downtime, it can assess whether there is a refrigerant deposition problem in the system. If refrigerant deposition is found, the auxiliary electronic expansion valve control program is activated. The system decides whether to start the heat pump system normally based on the refrigerant status. If refrigerant deposition exists, additional control measures are taken to avoid potential malfunctions after startup. The significance is that by confirming the refrigerant status before compressor startup, liquid slugging caused by liquid refrigerant deposition can be prevented, thus protecting the compressor and system components. It ensures that the heat pump can start under stable conditions, reducing maintenance and downtime caused by refrigerant problems and improving equipment reliability. Step S200 starts the control program and compares the threshold values. The auxiliary electronic expansion valve control program is activated to monitor the exhaust superheat and injection superheat in real time and compare them with reference thresholds. It checks whether the exhaust superheat is within the preset range of multiple exhaust superheat thresholds and whether the injection superheat is within the set range of multiple temperature thresholds. Based on the comparison results, the opening of the auxiliary electronic expansion valve is adjusted to achieve optimal refrigerant flow and system operation. Significance Achieved: Through precise adjustment, the heat pump can maintain good performance during the rapid oil return phase, achieving rapid and effective refrigerant recirculation and ensuring efficient system operation. Optimized refrigerant flow helps improve the heat pump's coefficient of performance (COP), reducing energy consumption and thus improving overall economy. Step S300 confirms the heat pump status and restores automatic control, confirming that key parameters such as compressor temperature, pressure, and exhaust superheat are within normal ranges, and confirming the stability of the refrigerant flow rate. After confirming the heat pump status is correct, the auxiliary circuit electronic expansion valve control program is unlocked, exiting the rapid oil return mode and restoring the normal heat pump automatic control mode. Significance Achieved: Ensures that all parameter settings are in a safe and stable state before entering the normal control mode, thereby avoiding instability and potential malfunctions during operation; achieves seamless switching between rapid oil return and normal operation, enabling the heat pump system to maintain good continuity during operation and improving working efficiency.

[0070] In summary, this embodiment ensures the safety and stability of the refrigerant during compressor startup and operation by progressively detecting and executing specific control procedures. This not only prevents malfunctions but also optimizes system operating efficiency and economy. Through monitoring and adjustment at different stages, high-efficiency operation and management of the heat pump system are achieved. By controlling the auxiliary circuit electronic expansion valve, the large amount of oil that leaks from the compressor during the refrigerant deposition startup phase is quickly returned to the compressor, ensuring that the operating components inside the compressor always have sufficient refrigerant oil lubrication, ensuring reliable compressor operation, and significantly improving product reliability.

[0071] Example 2: As Figure 2 As shown, based on Example 1, the process for determining the presence of refrigerant deposition based on ambient temperature and downtime provided in this embodiment of the invention includes the following steps:

[0072] S101: Collect the current ambient temperature of the compressor area through an ambient temperature sensor, obtain real-time monitoring data from the heat pump system and record the compressor's downtime; integrate the acquired ambient temperature and downtime data to form a dataset;

[0073] S102: Construct a refrigerant deposition judgment model, train it using multi-dimensional features of input ambient temperature and downtime, identify potential patterns of refrigerant deposition; output the probability value of refrigerant deposition; when the probability value exceeds the judgment threshold, it is considered that refrigerant deposition exists;

[0074] S103: Determine whether to start the auxiliary circuit electronic expansion valve control program or start the heat pump according to the normal program based on whether there is refrigerant deposit. If there is refrigerant deposit, start the auxiliary circuit electronic expansion valve control program, and the heat pump will be stopped in the normal program.

[0075] The working principle and beneficial effects of the above technical solution are as follows: Firstly, this embodiment collects the current ambient temperature of the compressor area through an ambient temperature sensor, obtains real-time monitoring data from the heat pump system, and records the compressor's downtime. The acquired ambient temperature and downtime are integrated to form a dataset. Secondly, a refrigerant deposition judgment model is constructed, trained using multi-dimensional features of the input ambient temperature and downtime, to identify potential refrigerant deposition patterns. A probability value indicating the presence of refrigerant deposition is output. When the probability value exceeds the judgment threshold, refrigerant deposition is considered to exist. Finally, based on the presence or absence of refrigerant deposition, it is determined whether to activate the auxiliary electronic expansion valve control program or start the heat pump according to the normal program. When refrigerant deposition exists, the auxiliary electronic expansion valve control program is activated, and the heat pump is stopped during the normal program startup. Step S101 of the above solution involves data collection and integration. Temperature data of the compressor area is collected in real-time through an ambient temperature sensor, and the compressor's downtime is recorded simultaneously to ensure data accuracy and real-time performance. The collected ambient temperature and downtime are integrated to form a multi-dimensional dataset that facilitates subsequent analysis. Significance: The formation of the dataset provides a foundation for the next step of judgment, ensuring sufficient information support for subsequent modeling and analysis; real-time monitoring and recording facilitate a comprehensive understanding of the compressor status, enabling precise control of the equipment's operating environment and contributing to improved operational safety and effectiveness; acquiring time-sensitive data allows the system to quickly identify and respond to changes in refrigerant status, reducing the impact on equipment performance. Step S102: Model Construction and Refrigerant Deposition Judgment. The constructed refrigerant deposition judgment model can identify potential refrigerant deposition patterns through input temperature and downtime parameters, improving the accuracy of the judgment; the model output is the probability value of refrigerant deposition, allowing the system to make more detailed judgments under dynamic conditions. Significance: Through the model's intelligent analysis capabilities, it can quickly and accurately determine whether refrigerant has deposited, overcoming the limitations of traditional static monitoring methods; the dynamic probability output reduces the uncertainty brought about by past experience-based judgments, thereby reducing the risk of false alarms and missed alarms and improving system reliability; the judgment model can adapt to different environmental conditions, supporting multiple operating strategies and condition changes, improving the system's intelligence level. Step S103 determines the start of the control program. Based on the determination of whether refrigerant deposits exist, the control strategy is automatically switched to enable the auxiliary electronic expansion valve or restore it to normal operation. Once refrigerant deposits are confirmed, the corresponding control program is immediately activated to ensure smooth refrigerant flow and prevent potential malfunctions. Significance: By responding quickly to this state, the risk of system failure caused by deposits is reduced, extending the service life of the equipment; by rationally controlling the flow of refrigerant, system energy efficiency is improved, heat pump performance is maintained, and efficient operation is achieved in different working modes; intelligent and efficient system control is realized, enhancing the user's confidence in the heat pump and improving user satisfaction.

[0076] In summary, this embodiment not only improves the system's intelligence level and operational safety, but also achieves effective management and optimization of refrigerant deposition through advanced data acquisition and processing, intelligent judgment and control. It possesses significant technical advantages in the face of equipment complexity and environmental variables, helping to drive the development of heat pump systems towards greater efficiency and autonomy, thereby enhancing their competitiveness in the market.

[0077] Example 3: As Figure 3 As shown, based on Example 2, the process of forming a dataset provided in this embodiment of the invention includes the following steps:

[0078] S1011: A short-time polling strategy is used to obtain temperature readings from temperature sensing devices. Multiple temperature measurement data are obtained within a time interval to form a temperature fluctuation spectrum. A timer is used to record the start-up and stop times of the compressor in real time. The compressor status changes are automatically sensed. When the compressor stops, the timer starts. The records include the duration of continuous compressor stop and the total stop time.

[0079] S1012: The collected ambient temperature and downtime are integrated and normalized in real time to form a multi-dimensional dataset; features are extracted from the temperature and time data to generate additional features, including the temperature change rate, to show abrupt temperature changes, downtime modes, and to identify which modes are related to refrigerant deposition.

[0080] S1013: Store the integrated and normalized dataset in the database; at the same time, implement version control of the dataset and save each version of the data for different running cycles.

[0081] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first uses a short-time polling strategy to acquire temperature readings from the temperature sensing device, acquiring multiple temperature measurement data within a time interval to form a temperature fluctuation spectrum; a timer is used to record the compressor's start-up and shutdown times in real time, automatically sensing changes in the compressor's state, and starting the timer when the compressor stops, including the duration of continuous compressor shutdown and the total shutdown time; secondly, the collected ambient temperature and shutdown time are integrated and normalized in real time to form a multi-dimensional dataset; feature extraction is performed on the temperature and time data to generate additional features, including the temperature change rate, to display abrupt temperature changes, shutdown patterns, and to identify which patterns are related to refrigerant deposition; finally, the integrated and normalized dataset is stored in a database; simultaneously, version control of the dataset is implemented, saving different versions of data for different operating cycles. The above solution's step S1011, temperature and downtime data acquisition, employs a short-time polling strategy to obtain frequent temperature readings from the temperature sensor. This ensures the capture of instantaneous temperature changes, forming a temperature fluctuation spectrum. Real-time monitoring provides a reliable temperature data foundation, reflecting environmental changes. A timer monitors the compressor's start-up and shutdown status in real time, automatically sensing changes and starting timing once a shutdown state is detected. This automatic sensing mechanism ensures accurate recording of downtime, including continuous downtime and total downtime. The significance is that real-time monitoring of temperature and shutdown status enables rapid response to environmental changes, improving the safety and reliability of the heat pump system. Frequent data measurement and recording enhance data coverage and representativeness, providing a precise foundation for subsequent analysis. Monitoring shutdown modes provides a basis for fault early warning and maintenance decisions. Step S1012, Data Integration and Feature Extraction, integrates and normalizes data from different sources (temperature and downtime) in real time to eliminate unit differences and dimensional issues, forming a unified multidimensional dataset. Based on the integrated dataset, feature extraction is performed, such as calculating temperature change rates and identifying downtime patterns. Additional features help the system to deeply analyze and mine potential refrigerant deposition patterns. Significance achieved: The formation of the multidimensional dataset enables systematic analysis of the relationship between temperature and downtime, making subsequent model construction more effective; feature extraction provides key indicators to help assess potential risks of refrigerant deposition and improve the accuracy of the assessment model; the integrated data and features provide operators with a scientific basis to optimize maintenance and operational decisions, thereby improving the overall system stability and efficiency. Step S1013, Data Storage and Version Control, stores the integrated and normalized dataset in a database to ensure data persistence and traceability, facilitating subsequent analysis and querying; version control of the dataset is implemented, saving data for different operating cycles, allowing the system to track historical data for comparison, analysis, and optimization.Significance achieved: Database storage ensures the long-term validity of important data and facilitates periodic review and analysis; the implementation of version control enables data backtracking and comparison under different circumstances, supporting the analysis of fault and performance change trajectories; the preservation and management of version data provides an important basis for subsequent model optimization and system improvement, promoting continuous innovation and iteration of the system in operation.

[0082] In summary, this embodiment forms a systematic and complete data acquisition and processing flow, ensuring the accuracy and effectiveness of the refrigerant deposition judgment logic; each step focuses on the acquisition and processing of real-time data, continuously reflecting state changes in a dynamic environment; ensuring that data integration, processing, and storage are all performed to a high standard, ensuring the effectiveness of subsequent analysis and decision-making; the above process is not limited to data collection, but also provides strong support for the autonomous judgment and adjustment of the intelligent system, thereby improving the overall intelligence level and operational efficiency of the heat pump system.

[0083] Example 4: Figure 4 As shown, based on Example 2, the process of constructing a refrigerant deposition judgment model provided in this embodiment of the invention includes the following steps:

[0084] S1021: Extract the features of factors affecting refrigerant deposition from the dataset, including temperature change rate, cumulative downtime, and stability index; divide the dataset into training set, validation set, and test set;

[0085] S1022: Random forest is applied to the training set to train the cold medium deposition judgment model. The optimization process uses cross-validation to adjust the hyperparameters.

[0086] S1023: Use the validation set to evaluate the performance of the trained refrigerant deposition judgment model. Evaluation metrics include: accuracy, precision, and recall. Output the probability value of refrigerant deposition. Embed the validated refrigerant deposition judgment model into the real-time monitoring system, set it to automatic operation mode, and receive and analyze ambient temperature and downtime data in real time.

[0087] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first extracts the features of factors affecting refrigerant deposition from the dataset, including temperature change rate, cumulative downtime, and stability index; the dataset is divided into training set, validation set, and test set; secondly, random forest is applied to the training set to train the refrigerant deposition judgment model, and the optimization process adopts cross-validation method to adjust hyperparameters; finally, the performance of the trained refrigerant deposition judgment model is evaluated using the validation set, and the evaluation indicators include: accuracy, precision, and recall; the probability value of refrigerant deposition is output; the validated refrigerant deposition judgment model is embedded into the real-time monitoring system, set to automatic operation mode, and receives and analyzes ambient temperature and downtime data in real time. Step S1021 of the above scheme involves feature extraction and dataset partitioning. Key features influencing refrigerant deposition (such as temperature change rate, cumulative downtime, and stability index) are extracted from the dataset. These features effectively capture dynamic changes in the environment and equipment status, helping the model more accurately identify refrigerant deposition phenomena. Feature selection and construction not only ensure the relevance of the input data but also enhance the model's expressive power, enabling it to better reflect the causes of refrigerant deposition. The overall dataset is divided into training, validation, and test sets to facilitate model training, adjustment, and evaluation, ensuring the reliability of the evaluation results and the model's generalization ability. Partitioning ensures the model's performance evaluation on unknown data, effectively preventing overfitting. The significance is that the extracted features help understand how various factors affect refrigerant deposition, thus providing strong data support for the design and maintenance decisions of heat pump systems. Multidimensional features enhance the model's ability to capture complex patterns, improving the accuracy of refrigerant deposition detection and reducing the probability of false alarms and false negatives. Step S1022 applies Random Forest for model training. Random Forest is an ensemble learning method that uses multiple decision trees for prediction, effectively reducing the bias that a single model might produce. The optimization process employs cross-validation, which fully utilizes information in the dataset, reduces the variance of model evaluation, and ensures the robustness and reliability of the model. By appropriately adjusting hyperparameters (such as the number of trees, maximum depth, etc.), the model's predictive performance can be improved, finding the most suitable combination of model parameters for the current data characteristics. Significance achieved: Random Forest performs excellently when handling high-dimensional data, effectively addressing the mutual influence between features, strengthening the overall performance of the model, and improving accuracy. Cross-validation and hyperparameter tuning ensure the systematic and rigorous training process, enabling the model to maintain high discriminative ability even in complex and changing data environments.Step S1023, Model Evaluation and Deployment, uses a validation set to evaluate the performance of the trained model, focusing on metrics such as accuracy, precision, and recall. These metrics comprehensively demonstrate the model's performance under various conditions. It outputs the probability value of refrigerant deposition, quantifying the risk and providing a basis for subsequent response decisions. The validated refrigerant deposition judgment model is embedded into a real-time monitoring system, enabling the model to receive and analyze temperature and downtime data in real time. After automated operation, the model can autonomously generate judgments and provide timely feedback without manual intervention. The significance of this step is as follows: Integration into the automation system enables rapid feedback on refrigerant deposition judgments, allowing for timely intervention and ensuring the safe and efficient operation of the heat pump system. The input of real-time operational data ensures continuous model optimization in dynamically changing environments, giving it adaptive capabilities and improving processing efficiency. It provides early warnings for maintenance: the output probability values ​​and judgment results provide timely warnings to maintenance personnel and assist in deciding whether to initiate appropriate maintenance or adjustment measures, improving the reliability and stability of the entire heat pump system.

[0088] In summary, this embodiment demonstrates a combination of data analysis, model training, and real-time response mechanisms in constructing the refrigerant deposition judgment model through the above steps. Each step has a significant impact on the performance and safety of the entire heat pump system. Overall, it achieves a closed loop from data acquisition to decision execution, providing a scientific and accurate solution for compressor control and refrigerant deposition management.

[0089] Example 5: Figure 5 As shown, based on Embodiment 2, the setting process of the auxiliary circuit electronic expansion valve control program provided in this embodiment of the invention includes the following steps:

[0090] S1031: Design a multi-level control program that includes three levels: data analysis, decision execution, and operation feedback. The first level is responsible for real-time data acquisition and status assessment, the second level is responsible for judgment logic and control decisions, and the last level is responsible for execution and feedback.

[0091] S1032: Using a trained refrigerant deposition detection model, the system analyzes ambient temperature and downtime, outputting a probability value indicating the presence of refrigerant deposition. When this probability value exceeds a set threshold, a refrigerant deposition indicator signal is immediately triggered. Upon detecting refrigerant deposition, the system immediately switches operating modes according to pre-defined priority rules, adjusting the opening degree of the auxiliary electronic expansion valve to meet refrigerant flow requirements. Simultaneously, it automatically sends a stop heat pump command, cutting off the heat pump startup procedure.

[0092] S1033: After obtaining the signal of refrigerant deposition, a stop signal is sent to the heat pump control loop through a programmable logic controller; a status feedback loop is established to detect the heat pump output status in real time through sensors to ensure that the stop command is effectively executed; if the feedback signal shows that the heat pump is still in the start state, the fault handling mechanism will be activated, the stop command will be resent and the fault will be investigated.

[0093] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first designs a multi-level control program containing three levels: data analysis, decision execution, and operation feedback. The first level is responsible for real-time data acquisition and status assessment, the second level performs judgment logic and control decisions, and the last level is responsible for execution and feedback. Secondly, using a trained refrigerant deposition judgment model, the ambient temperature and downtime are analyzed to output a probability value of refrigerant deposition. When the probability value exceeds a set threshold, a refrigerant deposition flag signal is immediately triggered. After determining that refrigerant deposition exists, the operating mode is immediately switched according to the pre-set priority rules, and the opening degree of the auxiliary electronic expansion valve is adjusted to respond to the refrigerant flow demand. At the same time, a stop heat pump command is automatically sent to cut off the heat pump start-up program. Finally, after obtaining the signal of refrigerant deposition, a stop signal is sent to the heat pump control loop through a programmable logic controller. A status feedback loop is established, and the heat pump output status is detected in real time by sensors to ensure that the stop command is effectively executed. If the feedback signal shows that the heat pump is still in the start-up state, the fault handling mechanism will be activated, the stop command will be resent, and fault troubleshooting will be performed. The above scheme's step S1031 involves a multi-level control program design. The first level collects environmental and system status data in real time through various sensors (such as temperature and pressure), transmitting the data to the control system to form a comprehensive status assessment basis. The second level utilizes a data analysis model to identify patterns from the collected data and generate real-time decisions, ensuring the accuracy of control actions. The third level is responsible for translating decisions into specific control commands and monitoring their execution for subsequent strategy adjustments. Significance: This multi-level control program design improves the system's flexibility and response speed, enabling it to quickly respond and optimize in the face of complex environmental changes, thus enhancing the system's overall intelligence and adaptability. Step S1032 involves refrigerant deposition judgment and operating mode switching. By using a trained refrigerant deposition judgment model, the collected ambient temperature and downtime are analyzed to generate probability values ​​for real-time judgment of refrigerant deposition. This predictive capability allows the system to respond promptly before problems manifest. Once refrigerant deposition is confirmed, the system immediately adjusts the operating mode according to preset priority rules, opens the auxiliary electronic expansion valve, and issues a command to stop the heat pump. Significance: It significantly improves the system's active protection capabilities, preventing potential equipment failures and avoiding more serious consequences caused by refrigerant deposits; through a rapid response mechanism, it ensures the safety and stability of the heat pump system under complex operating conditions.Step S1033 sends a stop signal and a status feedback loop. When the system confirms refrigerant deposition, a stop command is sent to the heat pump control loop via the programmable logic controller (PLC) to ensure the heat pump can stop in a timely and safe manner, avoiding further refrigerant deposition problems. A status feedback loop is established to monitor the actual operating status of the heat pump through sensors, ensuring the effective execution of the stop command. If the heat pump is still running, a stop command is reissued through a fault handling mechanism, and a fault diagnosis process is initiated to ensure reliable system operation. Significance: This ensures accurate transmission and feedback of the stop signal, reduces the risk that the system may suffer due to command failure, and enhances the reliability and intelligent response capability of the entire control system. It not only ensures the safe operation of the equipment but also provides a basis for subsequent fault diagnosis and maintenance verification, improving the maintainability of the system.

[0094] In summary, the series of setup steps in this embodiment complement each other, collectively constructing an intelligent, efficient, and safe auxiliary electronic expansion valve control system. By constructing a multi-level data analysis and feedback mechanism, employing a judgment model for refrigerant deposition early warning, and establishing an effective signal control and fault detection mechanism, proactive handling of refrigerant deposition problems is achieved, greatly improving the stability and safety of the heat pump system under complex operating conditions, and providing important reference and foundation for future applications in related fields.

[0095] Example 6: As Figure 6 As shown, based on Example 1, the process of controlling according to exhaust superheat or injection superheat provided in this embodiment of the invention includes the following steps:

[0096] S201: The auxiliary electronic expansion valve opens to the preset initial opening degree and maintains the state;

[0097] S202: Complete the initial opening setting, monitor and adjust the exhaust superheat in real time, and adjust the opening of the auxiliary electronic expansion valve according to the set conditions based on different superheat ranges;

[0098] S203: When the compressor is turned on and the exhaust superheat is detected to exceed the set monitoring benchmark threshold for the first time, the auxiliary electronic expansion valve exits the control mode of the refrigerant deposition start-up stage and enters the regulation of exhaust or injection superheat.

[0099] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, the auxiliary electronic expansion valve first opens to the preset initial opening at a rate of approximately 40P / 10s and maintains this state for 1-2 minutes; secondly, the initial opening setting is completed, and the exhaust superheat is monitored and adjusted in real time. According to different superheat ranges, the opening adjustment of the auxiliary electronic expansion valve is determined according to the set conditions; finally, when the compressor has been running for 5 minutes and the exhaust superheat is detected to exceed the set monitoring benchmark threshold for the first time, the auxiliary electronic expansion valve exits the control mode of the refrigerant deposition start-up stage and enters the regulation of exhaust or injection superheat. In step S201 of the above solution, the auxiliary electronic expansion valve opens to the preset initial opening at a rate of approximately 40P / 10s and maintains this state for 1 to 2 minutes to ensure that the refrigerant flow energy is quickly established; by setting the initial opening and maintaining it for a fixed duration, it is possible to ensure that an appropriate refrigerant flow can be provided during the initial start-up stage, avoiding flow fluctuations caused by instantaneous changes in opening, so as to protect other components of the system (such as the compressor) from being subjected to a stable load during startup. Significance: Establishing the initial state provides a solid foundation for subsequent fine-grained control, ensuring system stability during startup and reducing adverse effects on the compressor and the entire refrigeration system. Step S202 involves real-time monitoring and adjustment of exhaust superheat. After the initial opening setting is completed, real-time monitoring of exhaust superheat begins to ensure continuous understanding of the system's operating status. Valve openings are adjusted accordingly based on different superheat ranges. Based on pre-defined conditions, the auxiliary electronic expansion valve reacts to real-time data, ensuring optimized refrigerant flow and preventing liquid slugging or compressor oil shortage. Significance: The real-time monitoring and adjustment mechanism enhances the system's ability to handle unexpected situations and improves system reliability. Through precise control, the system can always maintain optimal operating conditions, thereby improving overall energy efficiency and stability. Step S203: The compressor exits the refrigerant deposition start-up phase after 5 minutes. When the compressor has been running for 5 minutes and the discharge superheat is detected to exceed the set reference threshold for the first time, the auxiliary electronic expansion valve automatically exits the refrigerant deposition start-up control mode and switches to normal discharge or injection superheat regulation. This state transition ensures the system can respond promptly to changes in the working environment. After switching to normal regulation mode, the auxiliary electronic expansion valve continues to adjust according to the discharge or injection superheat, allowing it to more flexibly handle different working conditions in daily operation. Significance: This ensures the system can adapt to changing operating conditions during the initial start-up and normal operation, and adjust operating strategies in a timely manner, effectively preventing equipment damage caused by refrigerant deposition or uncontrolled superheat; it can significantly improve equipment lifespan and overall system efficiency.

[0100] In this embodiment, before starting the compressor, it is first determined whether there is refrigerant deposit. Generally, ambient temperature and downtime are used as the conditions for determining refrigerant deposit. If refrigerant deposit is present during startup, the following control of the auxiliary electronic expansion valve is executed during the compressor startup phase:

[0101] After the compressor has been running for a period of time, this time ensures that the compressor has started stably and that most of the refrigeration oil is still in the compressor oil sump, generally 2 to 5 minutes.

[0102] The auxiliary electronic expansion valve opens to its initial opening at a certain rate (generally about 40P / 10s) and maintains it for a period of time (generally 1~2min). After that, the exhaust superheat is judged and the next step of control is carried out:

[0103] ① When the exhaust superheat condition in clause ② is not met, the auxiliary electronic expansion valve is controlled according to the target injection superheat to prevent compressor liquid slugging or oil shortage;

[0104] When the injection superheat is ≤ T1 (first temperature threshold), the auxiliary electronic expansion valve closes at a certain rate, generally about 3P / 10s;

[0105] When T1 < injection superheat ≤ T2 (second temperature threshold), the auxiliary electronic expansion valve closes at a certain rate, generally about 2P / 15s. The valve closing rate here is slower than the first step.

[0106] When T2 < injection superheat ≤ T3 (third temperature threshold), the auxiliary electronic expansion valve maintains its current opening.

[0107] When the injection superheat is greater than T3, the auxiliary electronic expansion valve opens at a certain rate, typically about 2P / 20s.

[0108] Note: T1 is generally taken as 1~3, T2 is generally taken as 4~7, and T3 is generally taken as 8~12;

[0109] ②When the auxiliary electronic expansion valve is opened and the compressor has been running for 5 minutes, once the exhaust superheat is detected to be greater than △T (monitoring reference threshold) for the first time, the auxiliary electronic expansion valve will exit the refrigerant deposition start-up stage control and be controlled according to exhaust superheat or injection superheat.

[0110] When the exhaust superheat is greater than P1 (the first exhaust superheat threshold), the auxiliary electronic expansion valve gradually opens in each adjustment cycle (the step size of each action generally does not exceed 2% of its maximum opening).

[0111] When P2 (second exhaust superheat threshold) ≤ exhaust superheat ≤ P1, injection superheat control is applied according to step ①.

[0112] When the exhaust superheat is less than P2, the auxiliary electronic expansion valve gradually closes in each adjustment cycle (the step size of each action generally does not exceed 2% of its maximum opening).

[0113] Note: △T is generally taken as 10~15; P1 is generally taken as 30~37, and P2 is generally taken as 12~18.

[0114] In summary, this embodiment provides a customized solution for the intelligent control of the auxiliary circuit electronic expansion valve. Its implementation can automatically adjust and optimize refrigerant flow during startup, ensuring the safe operation of the compressor and avoiding potential malfunctions caused by refrigerant deposits. This not only improves the safety and stability of refrigeration or heat pump systems but also effectively enhances energy efficiency and application flexibility.

[0115] Example 7: As Figure 7 As shown, based on Example 6, the process for obtaining exhaust superheat provided in this embodiment of the invention includes the following steps:

[0116] S2021: The actual temperature at the compressor's exhaust end is monitored in real time using an exhaust temperature sensor; at the same time, a high-pressure sensor monitors the high-pressure value.

[0117] S2022: Based on the known high pressure value, consult the refrigerant's characteristic table, and use the relationship between the refrigerant's saturated vapor pressure and the corresponding temperature to calculate the saturation temperature corresponding to the pressure.

[0118] S2023: The difference between the actual temperature and the saturation temperature is used to obtain the exhaust superheat, thus determining the safety of the compressor's exhaust state.

[0119] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first uses an exhaust temperature sensor to monitor the actual temperature at the compressor exhaust end in real time; simultaneously, a high-pressure sensor monitors the high-pressure value; secondly, based on the known high-pressure value, the refrigerant characteristic table is consulted, and the saturation temperature corresponding to the pressure is calculated using the relationship between the refrigerant's saturated vapor pressure and the corresponding temperature; finally, the difference between the actual temperature and the saturation temperature is used to obtain the exhaust superheat, thus determining the safety of the compressor's exhaust state. Step S2021 of the above solution involves real-time monitoring of the compressor exhaust temperature and high-pressure value, using the exhaust temperature sensor to monitor the actual temperature at the compressor exhaust end and the high-pressure value monitored by the high-pressure sensor, providing basic data support for calculations; real-time performance indicates that the system can quickly respond to changes in compressor operation, providing timely information for subsequent control decisions. Significance: By acquiring accurate temperature and pressure data, the system can grasp the compressor's operating status in real time, thereby establishing a solid foundation for subsequent steps; real-time data is a prerequisite for ensuring system safety, improving operating efficiency, and guaranteeing equipment stability. Step S2022 calculates the saturation temperature corresponding to the pressure. Based on the collected high-pressure value, the saturation temperature corresponding to that pressure is calculated by consulting the refrigerant's characteristic table. The accuracy of the saturation temperature is ensured by combining physical properties with changes in actual pressure. This step also supports the use of different refrigerant types, offering strong adaptability. Different characteristic tables can be selected for saturation temperature calculation according to the system, improving flexibility. Significance: The calculated saturation temperature provides a benchmark for judging the compressor's discharge state, helping the system determine the current state of the refrigerant (gaseous or liquid). It is crucial for assessing equipment safety and preventing liquid slugging, and also provides necessary parameters for subsequent discharge superheat calculation. Step S2023 calculates the discharge superheat. The discharge superheat is obtained by calculating the difference between the real-time monitored actual discharge temperature and the calculated saturation temperature. It directly reflects the compressor's discharge state, helping to determine whether the current refrigerant is within a safe operating range. Significance: The obtained discharge superheat is directly related to the system's safety and the normal operation of the compressor. Accurate assessment of exhaust superheat can prevent compressor damage caused by overheating, and also provides a basis for system operation monitoring and optimization; long-term monitoring of this parameter can also serve as an important basis for system debugging and optimization, improving equipment efficiency and lifespan.

[0120] In summary, this embodiment not only effectively collects and analyzes key system operating parameters during the acquisition of exhaust superheat, but its clear process design also ensures rapid processing and feedback of complex technical information. Through precise temperature and pressure data acquisition, scientific saturation temperature calculation, and intuitive superheat assessment, the operational safety of the compressor and the efficiency of system control are further improved, ensuring the reliability and stability of the refrigeration system. The technical design of this process is highly rational and innovative, providing crucial support for intelligent control in practical applications.

[0121] Example 8: As Figure 8 As shown, based on Example 6, the process for obtaining the jet superheat provided in this embodiment of the invention includes the following steps:

[0122] S2031: Use an auxiliary outlet temperature sensor to monitor the temperature of the auxiliary outlet end in real time; at the same time, use an auxiliary inlet temperature sensor to monitor the temperature of the auxiliary inlet end.

[0123] S2032: By comparing the outlet temperature and the inlet temperature, the temperature difference, i.e. the injection superheat, is calculated. It represents the temperature change of the refrigerant from the inlet end to the outlet end after passing through the system, reflecting the degree of refrigerant superheat.

[0124] S2033: Based on the result of the injection superheat, compare it with the set threshold. If the calculated injection superheat exceeds the preset value, the automatic adjustment mechanism will be activated to adjust the opening of the auxiliary electronic expansion valve through real-time feedback.

[0125] The working principle and beneficial effects of the above technical solution are as follows: Firstly, this embodiment uses an auxiliary outlet temperature sensor to monitor the temperature at the auxiliary outlet end in real time; simultaneously, an auxiliary inlet temperature sensor monitors the temperature at the auxiliary inlet end. Secondly, by comparing the auxiliary outlet and auxiliary inlet temperatures, the temperature difference, i.e., the injection superheat, is calculated, representing the temperature change of the refrigerant from the auxiliary inlet end to the auxiliary outlet end after passing through the system, reflecting the degree of refrigerant superheat. Finally, based on the result of the injection superheat, it is compared with a set threshold. If the calculated injection superheat exceeds the preset value, an automatic adjustment mechanism will be activated, adjusting the opening of the auxiliary circuit electronic expansion valve through real-time feedback. Step S2031 of the above solution involves real-time monitoring of the auxiliary outlet and auxiliary inlet temperatures, using auxiliary outlet and auxiliary inlet temperature sensors respectively to monitor the temperatures at the auxiliary outlet and auxiliary inlet ends in real time, ensuring accurate temperature information is obtained. Through real-time monitoring, the current refrigerant status can be quickly acquired and responded to, providing a reliable data foundation for subsequent calculations. Significance: Accurate temperature data is crucial for understanding the entire refrigeration cycle, laying a solid foundation for calculating the injection superheat. It reflects the actual performance of the refrigerant during operation, helping to identify potential problems and prevent malfunctions in a timely manner. Step S2032 calculates the injection superheat by comparing the monitored auxiliary outlet and auxiliary inlet temperatures. The calculation result directly reflects the degree of temperature rise of the refrigerant in the auxiliary circuit, indicating its superheat level, and providing a reference for evaluating refrigeration efficiency and safety. Significance: The calculation of injection superheat allows the system to quantify the thermal state of the refrigerant, providing an intuitive standard to determine whether the refrigerant is in a reasonable operating state. If the injection superheat is too high, it may affect the refrigeration effect and increase the risk of equipment damage. The calculation process is crucial for maintaining operational safety and system efficiency. Step S2033 compares the calculated injection superheat with the preset threshold and adjusts the electronic expansion valve. Based on the calculated injection superheat, it is compared with the system's preset safety threshold to ensure the refrigerant's operating state remains within a safe range. When the injection superheat exceeds the preset value, the system will activate an automatic adjustment mechanism, adjusting the opening of the auxiliary electronic expansion valve through real-time feedback to optimize refrigerant flow and pressure, thus regulating the system's operating state. Significance: The automatic adjustment mechanism allows for rapid response based on real-time monitoring data during operation, effectively preventing accidents caused by overheating. This proactive control strategy not only improves system safety and operational stability but also significantly enhances overall energy efficiency, ensuring the efficient and safe operation of the equipment.

[0126] In summary, this embodiment establishes a complete and efficient control system by combining real-time data acquisition, temperature difference calculation, and intelligent adjustment mechanisms in the process of obtaining jet superheat. Through precise data monitoring and calculation, it ensures that the equipment operates within a reasonable range, reduces the risk of failure, improves operational efficiency, and provides strong technical support for future intelligent development.

[0127] Example 9: As Figure 9 As shown, based on Embodiment 1, the process of the unlocking auxiliary circuit electronic expansion valve control program provided in this embodiment of the invention includes the following steps:

[0128] S301: Perform comprehensive monitoring of the compressor's temperature and pressure, including confirming whether the compressor's discharge superheat is within the safe threshold; use a flow sensor to monitor the refrigerant flow rate in real time, and if the flow rate is stable and within the preset range, proceed to the next step;

[0129] S302: Based on real-time monitoring results, the opening adjustment strategy of the auxiliary electronic expansion valve is used to obtain the opening setting parameters; the unlocking procedure is automatically executed to change the control program of the auxiliary electronic expansion valve from the locked state to the unlocked state;

[0130] S303: After unlocking, it will automatically switch to the automatic control mode of the heat pump; the opening of the auxiliary electronic expansion valve will be automatically adjusted according to changes in pressure, temperature and demand.

[0131] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first comprehensively monitors the temperature and pressure of the compressor, including confirming whether the compressor's exhaust superheat is within the safe threshold; it uses a flow sensor to monitor the refrigerant flow rate in real time, and if the flow rate is stable and within the preset range, it proceeds to the next step; secondly, based on the real-time monitoring results, it uses an auxiliary electronic expansion valve opening adjustment strategy to obtain the opening setting parameters; it automatically executes the unlocking procedure, switching the auxiliary electronic expansion valve control program from the locked state to the unlocked state; finally, after unlocking is completed, it automatically switches to the heat pump's automatic control mode; the opening of the auxiliary electronic expansion valve will be automatically adjusted according to changes in pressure, temperature, and demand. Step S301 of the above solution comprehensively monitors the compressor's temperature, pressure, and refrigerant flow rate. By comprehensively monitoring the compressor's temperature and pressure, it can accurately identify whether it is within the safe operating range, and simultaneously confirm whether the compressor's exhaust superheat is within the safe threshold; it uses a flow sensor to obtain the refrigerant flow rate in real time, ensuring that the flow rate is stable and within the preset range, laying the foundation for the system's unlocking process; it ensures that all monitoring data meet safety standards, thereby determining whether the conditions for unlocking are met. Significance: Ensuring normal compressor operation and refrigerant flow provides crucial safety assurance for subsequent unlocking operations, a prerequisite for stable operation, and plays a key role in preventing equipment damage or performance degradation. Step S302, the execution of the opening adjustment strategy and unlocking procedure, generates optimal opening settings for the auxiliary electronic expansion valve based on real-time monitoring data and factors such as flow rate, pressure, and temperature. It optimizes the opening configuration through intelligent algorithms to adapt to current system requirements. After confirming all conditions are met, it automatically switches the auxiliary electronic expansion valve control program from locked to unlocked state, ensuring the system can return to normal control at the appropriate time. Significance: Through intelligent adjustment and automated unlocking, the system can quickly and efficiently resume operation, reducing the need for human intervention and improving the automation level of the heat pump. It not only improves the system's response speed but also optimizes operational efficiency, representing an important aspect of intelligent management in modern heat pump systems. Step S303 completes the unlocking and switches to automatic control mode. After unlocking, the system can automatically switch to the heat pump's automatic control mode, allowing the opening of the auxiliary electronic expansion valve to be dynamically adjusted according to real-time pressure, temperature, and system requirements. This enables the system to flexibly respond to changes in the external and internal environment, improving the overall intelligence of the system's operation. Significance: Automatically switching to the heat pump control mode allows the system to efficiently and continuously adapt to different operating states and load demands, helping to maintain the heat pump's optimal operating efficiency and long-term stability. It provides a necessary foundation for the intelligent development of heat pump systems, promoting energy efficiency improvements and the achievement of energy-saving goals.

[0132] In summary, each step of the unlocking auxiliary circuit electronic expansion valve control program in this embodiment ensures that the system resumes normal operation in a safe and stable state. The combination of real-time monitoring, intelligent decision-making, and automatic control not only improves the efficiency and safety of the heat pump system but also lays a solid foundation for future intelligent control systems.

[0133] Example 10: As Figure 10 As shown, based on Example 9, the process of obtaining the auxiliary electronic expansion valve opening adjustment strategy provided in this embodiment of the invention includes the following steps:

[0134] S3021: Collects data from multiple sensors, including compressor temperature, pressure, discharge superheat, and refrigerant flow rate; cleans the collected data to remove outliers and noise; identifies key variables affecting the opening setting, including ambient temperature, system pressure, discharge superheat, and refrigerant flow rate.

[0135] S3022: Based on real-time monitoring of key variables, set objective functions to maximize cooling efficiency, minimize energy consumption, or minimize exhaust superheat; use acquired data and historical operating patterns to predict demand and adjust the opening degree.

[0136] S3023: Based on the obtained opening setting parameters, generate specific control commands and send them to the auxiliary electronic expansion valve; after performing the opening adjustment and obtaining the execution results, provide feedback on whether the settings have achieved the expected effect, thus forming a closed-loop control.

[0137] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first collects data from multiple sensors, including compressor temperature, pressure, exhaust superheat, and refrigerant flow rate. The collected data is cleaned to remove outliers and noise. Key variables affecting the opening setting are identified, including ambient temperature, system pressure, exhaust superheat, and refrigerant flow rate. Secondly, based on the key variables monitored in real time, an objective function is set to maximize cooling efficiency, minimize energy consumption, or minimize exhaust superheat. Demand is predicted using the acquired data and historical operating modes, and the opening is adjusted accordingly. Finally, based on the obtained opening setting parameters, specific control commands are generated and sent to the auxiliary electronic expansion valve. After the opening adjustment is executed and the results are obtained, feedback is provided on whether the setting has achieved the expected effect, forming a closed-loop control. Step S3021 of the above scheme involves data collection and cleaning. This involves collecting data from various sensors, including compressor temperature, pressure, exhaust superheat, and refrigerant flow rate, to achieve comprehensive monitoring of the system's operating status. Outliers and noise are removed to ensure data accuracy and reliability, laying the foundation for data analysis and decision-making. By analyzing and comparing different variables, the key variables with the greatest impact on the electronic expansion valve opening setting are identified, providing important basis for subsequent optimization. Significance: This ensures the reliability of the information acquired by the system, thereby improving the effectiveness of subsequent decision-making. Accurate data support is a prerequisite for efficient control, helping the system maintain stable performance under rapidly changing operating conditions. Step S3022 involves setting the objective function and demand forecasting. This involves setting an objective function to maximize cooling efficiency, minimize energy consumption, or minimize exhaust superheat, ensuring that the opening adjustment target is clear and measurable. Combining real-time monitoring data and historical operating patterns, the system's cooling demand is predicted, providing forward-looking data support for opening adjustment. The opening setting is flexibly adjusted according to constantly changing system needs and conditions to better adapt to the current operating state. Significance: This enhances the system's intelligent management capabilities. Data-driven prediction and analysis enable more effective adaptation to changing operating environments, reducing energy waste and efficiency losses. A clear objective function allows for a more scientific formulation of subsequent control strategies. Step S3023: Control Command Generation and Closed-Loop Feedback. Based on the optimized opening setting parameters, specific control commands are generated and transmitted to the auxiliary electronic expansion valve to ensure accurate and timely execution. After opening adjustment, the sensor provides feedback on the actual effect, comparing the actual adjustment with the expected effect to form closed-loop control. Through analysis of the feedback results, subsequent opening settings are adjusted in real time to optimize the control process. Significance: By implementing closed-loop control, the system can continuously optimize during actual operation and flexibly adjust opening settings based on feedback information, thereby maximizing system efficiency. This improves the adaptability and efficiency of the overall control strategy, ensuring the heat pump system maintains its established performance during long-term operation.

[0138] In summary, this embodiment achieves a complete closed loop from data collection to decision execution in the acquisition process of the auxiliary electronic expansion valve's opening adjustment strategy. This strengthens the fundamental role of data and promotes improved accuracy and reliability. It clarifies the optimization objectives, providing theoretical support for dynamic adjustment. Furthermore, the implementation of a closed-loop feedback mechanism enables the system's self-optimization and continuous improvement. This not only improves system operating efficiency but also lays a solid foundation for future system expansion and upgrades, making it an important means of achieving intelligent and efficient heat pumps.

[0139] Example 11: As Figure 11 As shown, based on Embodiments 1-10, the heat pump system provided in this embodiment of the invention includes: a compressor 1, a low-pressure sensor 2, a return gas temperature sensor 3, an auxiliary electronic expansion valve 4, a finned tube heat exchanger 5, an ambient temperature sensor 6, a water-side heat exchanger 7, a main electronic expansion valve 8, an economizer 9, an auxiliary outlet temperature sensor 10, an auxiliary inlet temperature sensor 11, a four-way valve 12, a high-pressure sensor 13, and an exhaust temperature sensor 14.

[0140] The compressor 1 is connected to the S end of the four-way valve 12 via a pipeline, a low-pressure sensor 2, and a return gas temperature sensor 3. An ambient temperature sensor 6 is installed at the bottom of the finned tube heat exchanger 5. One end of the finned tube heat exchanger 5 is connected to the E end of the four-way valve 12. The other end of the finned tube heat exchanger 5 is connected to the main electronic expansion valve 8 and the economizer 9. The economizer 9 is connected to the auxiliary outlet temperature sensor 10 and the auxiliary inlet temperature sensor 11. The auxiliary inlet temperature sensor 11 is connected to the auxiliary electronic expansion valve 4. The auxiliary outlet temperature sensor 10 is connected to the compressor 1. The C end of the four-way valve 12 is connected to the water-side heat exchanger 7. The water-side heat exchanger 7 is connected to the economizer 9. The compressor 1 is connected to the D end of the four-way valve 12 via an exhaust temperature sensor 14 and a high-pressure sensor 13.

[0141] The working principle and beneficial effects of the above technical solution are as follows: After startup, compressor 1 compresses the low-pressure refrigerant gas, increasing the pressure and temperature of the refrigerant. The refrigerant's status is monitored by exhaust temperature sensor 14 and high-pressure sensor 13 to ensure it operates within a safe range. Four-way valve 12 is responsible for switching between heating and cooling modes, guiding the refrigerant flow as needed. Its S-terminal receives signals from low-pressure sensor 2 and return gas temperature sensor 3 to ensure the refrigerant flow required by the compressor is reasonable. When the refrigerant flows through finned tube heat exchanger 5, ambient temperature sensor 6 monitors the surrounding ambient temperature. The refrigerant absorbs or releases heat here, depending on the current operating mode. Finned tube heat exchanger 5 achieves efficient heat exchange to provide the required heat to the target environment. After passing through the finned tube heat exchanger, the refrigerant flows into the main electronic expansion valve 8, and after depressurization, enters the economizer 9. The design of economizer 9 improves system efficiency and reduces power consumption. Auxiliary electronic expansion valve 4 ensures flow control in the auxiliary circuit, optimizing refrigerant usage. The water-side heat exchanger 7 is connected to the C end of the four-way valve and is responsible for heat exchange with the water system (e.g., heating or cooling), realizing the heat transfer between the refrigerant and water. In the entire system, the auxiliary outlet temperature sensor 10 and the auxiliary inlet temperature sensor 11 monitor the inlet and outlet temperatures of the heat medium to ensure the system's operating efficiency, while also providing information for regulating the closed-loop feedback.

[0142] This embodiment effectively converts low-grade heat (such as heat from ambient air, ground, or water) into high-grade heat energy for heating, achieving efficient heat transfer. The four-way valve regulates the system's switching between heating and cooling, making the heat pump system multifunctional and adaptable to different user needs. Various sensors monitor temperature and pressure in real time, ensuring the system's safety and stability under various operating conditions and promptly correcting any anomalies. Using renewable resources (such as air and ground) as a heat source helps reduce fossil fuel consumption, achieving environmental protection and energy conservation goals. Significance: The design and operating principle of the heat pump system make it more energy-efficient than traditional heating and cooling systems, reducing energy consumption and thus carbon emissions. Its flexibility allows it to operate in different seasons and environmental conditions, meeting diverse user needs. Its energy-saving effect results in relatively low long-term operating costs, improving economic benefits. Real-time monitoring and dynamic adjustment ensure system stability, reducing downtime caused by equipment failure or performance degradation.

[0143] In summary, this embodiment effectively integrates various components and sensors, resulting in excellent performance in efficient heat exchange and conversion, while also possessing flexibility and stability, providing users with an economical and environmentally friendly solution.

[0144] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of equivalents of this invention, this invention is also intended to include these modifications and variations.

Claims

1. A method for rapid oil return in a heat pump system, characterized in that, A heat pump system includes: a compressor, piping, a low-pressure sensor, and a return gas temperature sensor; The compressor is connected to the S end of the four-way valve via pipelines, a low-pressure sensor, and a return gas temperature sensor. An ambient temperature sensor is installed at the bottom of the finned tube heat exchanger. One end of the finned tube heat exchanger is connected to the E end of the four-way valve. The other end of the finned tube heat exchanger is connected to the main circuit electronic expansion valve and the economizer. The economizer is connected to the auxiliary outlet temperature sensor and the auxiliary inlet temperature sensor. The auxiliary inlet temperature sensor is connected to the auxiliary circuit electronic expansion valve. The auxiliary outlet temperature sensor is connected to the compressor. The C end of the four-way valve is connected to the water-side heat exchanger. The water-side heat exchanger is connected to the economizer. The compressor is connected to the D end of the four-way valve via an exhaust temperature sensor and a high-pressure sensor. Includes the following steps: Before the compressor starts, the ambient temperature and downtime are obtained, and the presence of refrigerant deposits is determined based on the ambient temperature and downtime. If refrigerant deposits are present, the auxiliary circuit electronic expansion valve control program is activated; if no refrigerant deposits are present, the heat pump is started according to the normal procedure. The auxiliary electronic expansion valve control program is started to compare the exhaust superheat with the monitoring benchmark threshold to confirm whether control is performed according to exhaust superheat or injection superheat. At the same time, the opening degree of the auxiliary electronic expansion valve is confirmed by comparing the exhaust superheat with multiple exhaust superheat thresholds and the injection superheat with multiple temperature thresholds. Confirm that the compressor temperature, pressure and discharge superheat are within the normal range, confirm that the refrigerant flow rate is stable, unlock the auxiliary circuit electronic expansion valve control program, exit the rapid oil return mode, and restore the heat pump to the automatic control mode. After the compressor starts; The auxiliary electronic expansion valve opens to its initial opening and maintains it. Then, it determines the exhaust superheat and proceeds with the next control step. If the exhaust superheat condition in clause ② is not met, the auxiliary electronic expansion valve shall be controlled according to the target injection superheat. When the injection superheat is less than or equal to the first temperature threshold T1, the auxiliary electronic expansion valve is partially closed. When T1 < injection superheat ≤ second temperature threshold T2, the auxiliary electronic expansion valve closes slightly, and the valve closing rate is slower than the first step. When T2 < injection superheat ≤ third temperature threshold T3, the auxiliary electronic expansion valve maintains its current opening. When the injection superheat is greater than T3, the auxiliary electronic expansion valve opens wider; ②When the auxiliary electronic expansion valve is opened and the compressor is started for 5 minutes, if the exhaust superheat is detected to be greater than the monitoring reference threshold △T for the first time, the auxiliary electronic expansion valve will exit the refrigerant deposition start-up stage control and be controlled according to exhaust superheat or injection superheat. When the exhaust superheat exceeds the first exhaust superheat threshold P1, the auxiliary electronic expansion valve gradually opens in each adjustment cycle, with each action step not exceeding 2% of its maximum opening. When the second exhaust superheat threshold P2 ≤ exhaust superheat ≤ P1, the injection superheat control shall be applied according to ①. When the exhaust superheat is less than P2, the auxiliary electronic expansion valve gradually closes in each adjustment cycle, with each action step not exceeding 2% of its maximum opening.

2. The rapid oil return method for a heat pump system as described in claim 1, characterized in that, Determining whether refrigerant deposition occurs based on ambient temperature and downtime includes the following steps: The current ambient temperature of the compressor area is collected by an ambient temperature sensor, and the compressor downtime is monitored and recorded in real time from the heat pump system. The acquired ambient temperature and downtime are integrated to form a dataset. A refrigerant deposition judgment model was constructed and trained using multi-dimensional features of input ambient temperature and downtime to identify potential patterns of refrigerant deposition. Output the probability value of refrigerant deposition; when the probability value exceeds the judgment threshold, it is considered that refrigerant deposition exists. Depending on whether refrigerant deposits are present, determine whether to activate the auxiliary circuit electronic expansion valve control program or start the heat pump according to the normal program. If refrigerant deposits are present, activate the auxiliary circuit electronic expansion valve control program, and the heat pump will be stopped during the normal program.

3. The rapid oil return method for a heat pump system as described in claim 2, characterized in that, The process of creating a dataset includes the following steps: A short-time polling strategy is used to acquire temperature readings from temperature sensing devices. Multiple temperature measurement data are acquired within a time interval to form a temperature fluctuation spectrum. A timer is used to record the start-up and stop times of the compressor in real time. The compressor status changes are automatically sensed. When the compressor stops, the timer starts. The records include the duration of continuous compressor stop and the total stop time. The collected ambient temperature and downtime data are integrated and normalized in real time to form a multidimensional dataset. Feature extraction is performed on the temperature and time data to generate additional features, including the temperature change rate, to show abrupt temperature changes and downtime patterns, and to identify which patterns are related to refrigerant deposition. The integrated and normalized dataset is stored in the database; version control of the dataset is also implemented, saving different versions of the data for different operating cycles.

4. The rapid oil return method for a heat pump system as described in claim 2, characterized in that, The process of constructing a refrigerant deposition judgment model includes the following steps: From the dataset, we extract the features of factors that influence the addition of refrigerant deposition, including the rate of temperature change, cumulative downtime, and stability index; we then divide the dataset into training, validation, and test sets. Random forest was applied to the training set to train the cold medium deposition judgment model. The optimization process used cross-validation to adjust the hyperparameters. The trained refrigerant deposition detection model was evaluated using a validation set. Evaluation metrics included accuracy, precision, and recall. The model output the probability value of refrigerant deposition. The validated refrigerant deposition detection model was then embedded into a real-time monitoring system and set to automated operation mode to receive and analyze ambient temperature and downtime data in real time.

5. The rapid oil return method for a heat pump system as described in claim 2, characterized in that, The setup process for the auxiliary circuit electronic expansion valve control program includes the following steps: Design a multi-level control program that includes three levels: data analysis, decision execution, and operation feedback. The first level is responsible for real-time data acquisition and status assessment, the second level is responsible for judgment logic and control decisions, and the last level is responsible for execution and feedback. Using a trained refrigerant deposition detection model, the system analyzes ambient temperature and downtime to output a probability value indicating the presence of refrigerant deposition. When this probability value exceeds a set threshold, a refrigerant deposition indicator signal is immediately triggered. Upon detecting refrigerant deposition, the system immediately switches operating modes according to pre-defined priority rules, adjusting the opening degree of the auxiliary electronic expansion valve to meet refrigerant flow requirements. Simultaneously, it automatically sends a stop heat pump command, cutting off the heat pump startup procedure. After obtaining the signal of refrigerant deposition, a stop signal is sent to the heat pump control loop through a programmable logic controller; A status feedback loop is established to monitor the heat pump output status in real time through sensors, ensuring that the stop command is effectively executed. If the feedback signal shows that the heat pump is still in the start-up state, the fault handling mechanism will be activated to resend the stop command and troubleshoot the fault.

6. The rapid oil return method for a heat pump system as described in claim 1, characterized in that, The process of obtaining exhaust superheat includes the following steps: The actual temperature at the compressor's exhaust end is monitored in real time using an exhaust temperature sensor; simultaneously, a high-pressure sensor monitors the high-pressure value. Based on the known high pressure value, consult the refrigerant's property table, and use the relationship between the refrigerant's saturated vapor pressure and corresponding temperature to calculate the saturation temperature corresponding to the pressure. The difference between the actual temperature and the saturation temperature is used to obtain the exhaust superheat, which determines the safety of the compressor's exhaust state.

7. The rapid oil return method for a heat pump system as described in claim 1, characterized in that, The process of obtaining superheat from the jet includes the following steps: The temperature at the auxiliary output end is monitored in real time using an auxiliary output temperature sensor; at the same time, the temperature at the auxiliary inlet end is monitored using an auxiliary inlet temperature sensor. By comparing the outlet temperature and the inlet temperature, the temperature difference, i.e. the injection superheat, is calculated. This represents the temperature change of the refrigerant from the inlet end to the outlet end after it passes through the system, reflecting the degree of refrigerant superheat. Based on the result of the injection superheat, it is compared with the set threshold. If the calculated injection superheat exceeds the preset value, the automatic adjustment mechanism will be activated to adjust the opening of the auxiliary electronic expansion valve through real-time feedback.

8. The rapid oil return method for a heat pump system as described in claim 1, characterized in that, The process of unlocking the auxiliary circuit electronic expansion valve control program includes the following steps: The compressor's temperature and pressure are comprehensively monitored, including confirming whether the compressor's exhaust superheat is within the safe threshold; the refrigerant flow rate is monitored in real time using a flow sensor, and if the flow rate is stable and within the preset range, the next step is carried out. Based on real-time monitoring results, the opening adjustment strategy of the auxiliary electronic expansion valve is determined, and the opening setting parameters are obtained; the unlocking procedure is automatically executed to switch the auxiliary electronic expansion valve control program from the locked state to the unlocked state. Once unlocked, it automatically switches to the heat pump's automatic control mode; the opening of the auxiliary electronic expansion valve will automatically adjust according to changes in pressure, temperature, and demand.

9. The rapid oil return method for a heat pump system as described in claim 8, characterized in that, The process of obtaining the opening adjustment strategy of the auxiliary circuit electronic expansion valve includes the following steps: Data from multiple sensors is collected, including compressor temperature, pressure, discharge superheat, and refrigerant flow rate. The collected data is cleaned to remove outliers and noise. Key variables affecting the opening setting are identified, including ambient temperature, system pressure, discharge superheat, and refrigerant flow rate. Based on key variables monitored in real time, set objective functions to maximize cooling efficiency, minimize energy consumption, or minimize exhaust superheat; use acquired data and historical operating patterns to predict demand and adjust the opening degree. Based on the obtained opening setting parameters, specific control commands are generated and sent to the auxiliary electronic expansion valve; after the opening adjustment is executed and the execution is obtained, feedback is provided on whether the setting has achieved the expected effect, thus forming a closed-loop control.

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