A refrigerant leak early warning system and method

Abstract

This invention discloses a refrigerant leakage early warning system and method. The method includes the following steps: collecting and preprocessing temperature and pressure data from an air conditioning unit; calculating the remaining refrigerant level using the temperature and pressure data and a physical property database; and outputting an early warning signal based on the current refrigerant level, leakage trend, and real-time leakage rate. The early warning signal includes a low-pressure warning and the remaining time for triggering the low-pressure warning. The early warning method provided by this invention offers high calculation accuracy and reliable data, and does not rely on large amounts of data or historical data. It can monitor the refrigerant level within the system, promptly detect anomalies, provide accurate early warnings, prevent system failures, ensure the normal operation of the air conditioning unit, and improve system reliability.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and more specifically to a refrigerant leakage early warning system and method. Background Technology

[0002] As an important mode of transportation, the comfort of high-speed trains, especially the operation of their air conditioning, has a significant impact on passengers' travel experience. Besides the stable operation of all components, the cooling capacity of the train's air conditioning system is one of the most critical performance indicators, and the refrigerant level within the system is a crucial factor affecting cooling efficiency.

[0003] Currently, the monitoring of the air conditioning system's operational status in high-speed trains mainly focuses on supply and return air temperatures, system pressure, and operating current of various loads. When refrigerant leaks continuously and the pressure falls below a certain threshold, a pressure alarm is triggered, requiring the air conditioning unit to be shut down for maintenance, affecting normal train operation. Furthermore, traditional monitoring methods struggle to accurately calculate the refrigerant level within the system, failing to provide accurate early warning information and increasing the risk of system failure.

[0004] In summary, there is a need to design a refrigerant leakage early warning system and method to solve the aforementioned problems in the existing technology. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a refrigerant leakage early warning system and method, which solves the problem that traditional monitoring methods are unable to accurately calculate the amount of refrigerant in the system and cannot provide accurate early warning information.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for early warning of refrigerant leaks, comprising the following steps:

[0008] Collect and preprocess temperature and pressure data from the air conditioning unit;

[0009] Calculate the refrigerant margin using temperature and pressure data, combined with a physical property database;

[0010] Based on the current refrigerant balance, leakage trend, and real-time leakage rate, an early warning signal is output.

[0011] The warning signal includes: a low-pressure warning and the remaining time for triggering the low-pressure warning.

[0012] In some embodiments of the present invention, calculating the refrigerant balance includes the following steps:

[0013] Determine the type of refrigerant;

[0014] Dryness data is obtained based on temperature and pressure data;

[0015] Obtain gas phase density, liquid phase density, and volume parameters;

[0016] Calculate the refrigerant balance using the following formula:

[0017]

[0018] In some embodiments of the present invention, the dryness data, the gas phase density, and the liquid phase density are all obtained by calling a physical property database.

[0019] In some embodiments of the present invention, the volume parameters are obtained by calculation using a known filling volume or by system settings.

[0020] In some embodiments of the present invention, the fitting process for the leakage trend includes:

[0021] Calculate and save the daily, weekly, and monthly leakage rates of the refrigerant;

[0022] The stored leakage rate data was fitted using an exponential fitting method to obtain the predicted trend of the corresponding leakage rate.

[0023] In some embodiments of the present invention, the calculation process for the refrigerant surplus further includes:

[0024] When the dryness data is abnormal, the system compares the pressure data with the saturation pressure at the current temperature to determine whether the refrigerant is in a pure liquid phase or a pure gas phase.

[0025] In some embodiments of the present invention, the temperature data and pressure data are obtained by measuring the temperature and pressure data using temperature sensors and pressure sensors while the air conditioning system is off; the preprocessing of the temperature and pressure data includes:

[0026] The Kalman filter algorithm is used to clean and filter the data collected by the sensor.

[0027] The filtered data is smoothed using the moving average method.

[0028] In some embodiments of the present invention, a refrigerant leak warning system includes:

[0029] The acquisition module is used to collect temperature and pressure data from the air conditioning unit.

[0030] The refrigerant balance calculation module is communicatively connected to the data acquisition module. The refrigerant balance calculation module is used to calculate the refrigerant balance based on the temperature data and pressure data.

[0031] The leakage early warning module is used to output early warning signals based on the current refrigerant balance, the fitted leakage trend, and the real-time leakage rate of the refrigerant.

[0032] The communication module is used to communicate with external devices.

[0033] In some embodiments of the present invention, an electronic device is provided, comprising:

[0034] A processor, and a memory and a transceiver communicatively connected to the processor;

[0035] The memory stores computer-executed instructions; the transceiver is used for sending and receiving data.

[0036] The processor executes the computer execution instructions stored in the memory to implement the aforementioned early warning method.

[0037] In some embodiments of the present invention, a computer-readable storage medium is provided, characterized in that,

[0038] The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the aforementioned early warning method.

[0039] The technical solution of the present invention has the following technical effects compared with the prior art:

[0040] The refrigerant balance calculation scheme provided by this invention has high calculation accuracy and reliable data. It can monitor the refrigerant level in the system and detect abnormalities in a timely manner without relying on big data or historical data. At the same time, it can provide accurate early warning, avoid system failures, ensure the normal operation of the air conditioning unit, and improve system reliability.

[0041] In addition, this method can also be used to realize volume calculation, leakage rate calculation and fault prediction functions, and comprehensively monitor the system status; it has wide applications. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram showing the installation location of the module in the air conditioning unit.

[0044] Figure 2 This is a schematic diagram of the structure of the refrigerant leakage early warning system.

[0045] Figure 3 This is a schematic diagram of the structure of the electronic device.

[0046] Reference numerals: 100, computing device; 110, acquisition module; 111, high-pressure temperature sensor; 112, high-pressure pressure sensor; 113, low-pressure temperature sensor; 114, low-pressure pressure sensor; 120, margin calculation module; 130, leakage early warning module; 140, communication module; 150, display module; 200, electronic device; 210, processor; 220, memory; 230, transceiver; 310, compressor; 320, high-pressure switch; 330, low-pressure switch; 340, gas-liquid separator; 350, evaporator; 360, throttling element; 370, dryer filter; 380, condenser. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0049] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, direct connections, or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0052] The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0053] Example 1

[0054] A method for early warning of refrigerant leaks, comprising the following steps:

[0055] Step 1: Collect and preprocess the temperature and pressure data of the air conditioning unit;

[0056] S11. Regarding data acquisition: The temperature and pressure data are both obtained by measuring the temperature and pressure sensors when the air conditioning system is off.

[0057] Reference Figure 1 As shown, high-speed trains generally use unit-type air conditioning units, employing a single-stage compression refrigeration cycle system. The main circulating components include a compressor 310, condenser, dryer filter 370, gas-liquid separator 340, evaporator 350, throttling element 360, liquid line solenoid valve, and bypass valve. Auxiliary heat exchange devices include evaporator fans and condenser fans, used to enhance condensation heat dissipation and evaporation heat absorption, and to deliver the air cooled and dehumidified by the evaporator 350 into the passenger compartment. A certain mass of refrigerant is sealed within the refrigeration system, driven by the compressor 310, circulating within the system piping. It undergoes a gas-liquid phase change within the condenser and evaporator 350, releasing or absorbing heat, ultimately dissipating heat from the passenger compartment to the outside, lowering the indoor temperature, causing condensation, and reducing indoor humidity.

[0058] Because the air conditioning unit experiences significant pressure and temperature differences during operation, even within the same heat exchanger, pressure variations can occur at different locations due to factors such as the heat exchange process, temperature differences, and pipe friction resistance. Furthermore, the refrigerant undergoes a rapid phase change, making accurate measurement of various parameters difficult. Therefore, to facilitate research and future applications, the air conditioning unit structure is simplified using a model.

[0059] First, the monitoring of refrigerant is simplified to the period when the air conditioning unit is shut down. At this time, the pressure in the system tends to be balanced and the phase state of the refrigerant is relatively stable, which makes it easy to measure the state parameters. Second, in further research, the air conditioning unit in the shutdown state can be simplified to a closed refrigerant storage tank. The tank volume is relatively easy to determine and the pressure and temperature parameters are also easy to measure.

[0060] The compressor 310 is equipped with a high-pressure switch 320 on the high-pressure side and a low-pressure switch 330 on the low-pressure side. The pressure sensor is used to monitor the pressure changes in the refrigeration system. The pressure sensor includes a high-pressure sensor 112 and a low-pressure sensor 114, which are respectively installed on the high-pressure side and the low-pressure side of the compressor.

[0061] Temperature sensors are used to monitor temperature changes inside the system. The temperature sensors include a high-pressure temperature sensor 111 and a low-pressure temperature sensor 113, which are respectively installed on the high-pressure side and the low-pressure side of the compressor.

[0062] S12, System Static Judgment Steps:

[0063] Since the system functions are implemented under static conditions, it is necessary to determine the static state of the system. This is done by detecting the high-pressure side pressure and the low-pressure side pressure, and calculating the ratio of the average value to the high-pressure side pressure. Only when the ratio is lower than a certain set value can the next calculation be performed. This set value is determined based on the user's required time for displaying the leakage rate.

[0064] S13. Preprocessing of the temperature and pressure data includes:

[0065] S131. Multiple Data Acquisition and Averaging: The system acquires data multiple times (default 10 times, with a 1-second interval between each acquisition) using temperature and pressure sensors on both the high-pressure and low-pressure sides to obtain multiple temperature and pressure readings. This multiple data acquisition method effectively reduces random errors in a single data reading.

[0066] S132. Use the Kalman filter algorithm to clean and filter the data collected by the sensor to ensure data reliability:

[0067] Kalman filtering is a recursive algorithm that reduces noise by weighting the measured and predicted values. Its basic idea is to combine the current measurement with previous predictions to obtain a new estimate, thereby eliminating noise interference to some extent.

[0068] In addition, the algorithm incorporates an exception handling mechanism during data reading. If an anomaly occurs while reading sensor data, the system will capture the anomaly information and notify the user, ensuring the reliability of data reading.

[0069] S133. Smooth the filtered data using the moving average method:

[0070] To further reduce data fluctuations, the system employs a data smoothing method. Smoothing the data using a moving average method can further reduce random fluctuations, making the calculation results more stable and reliable.

[0071] Step 2: Calculate the refrigerant margin using temperature and pressure data, combined with a physical property database;

[0072] S21. Determine the type of refrigerant;

[0073] S22. Obtain dryness data based on temperature and pressure data;

[0074] Here, dryness fraction x refers to the percentage of dry steam contained in each kilogram of wet steam. The percentage of gaseous refrigerant in the system at the corresponding temperature and pressure can be found in the physical property database.

[0075] S23. Obtain the gas phase density, liquid phase density, and volume parameters;

[0076] gas phase density ρ gas This refers to the density of the gaseous refrigerant, which can be obtained by consulting a physical property database; it is expressed in kg / m³. 3 .

[0077] Liquid phase density ρ liquid This refers to the density of the liquid refrigerant, which can be obtained by consulting a physical property database, in kg / m³. 3 .

[0078] The volume parameters are obtained by measuring nitrogen filling or by setting the system.

[0079] The formula for the concept of dryness is:

[0080]

[0081] The mass ratio of gas to liquid phase is

[0082]

[0083] Among them, gas phase mass m gas : Total mass of gaseous refrigerant in the system, kg.

[0084] liquid phase mass m liqud : Total mass of liquid refrigerant in the system, kg.

[0085] For volume parameters, they can be calculated by inversely using the mass calculation formula after filling the system with a known mass.

[0086]

[0087] The total mass m total The total mass of refrigerant in the system is a known quantity that is substituted into the calculation.

[0088] Liquid phase density ρ liquid This refers to the density of the liquid refrigerant, which can be obtained by consulting a physical property database, in kg / m³. 3 .

[0089] gas phase density ρ gas This refers to the density of the gaseous refrigerant, which can be obtained by consulting a physical property database; it is expressed in kg / m³. 3 .

[0090] S24. Calculate the refrigerant balance:

[0091] m gas =V gas ×ρ gas m liquid =V liquid ×ρ liquid ,

[0092] Combined with V total =V gas +V liqud m total =m gas +m liqud ,

[0093] The final equation for calculating the total mass is as follows:

[0094]

[0095] Wherein, liquid phase volume V liquid Total volume of liquid refrigerant in the system, in m³ 3

[0096] gas volume V gas The total volume of the gaseous refrigerant in the system, plus the volume of the liquid phase, equals the system volume (m³). 3 .

[0097] When the dryness data is abnormal, the system compares the pressure data with the saturation pressure at the current temperature to determine whether the refrigerant is in a pure liquid phase or a pure gas phase.

[0098] In the subcooled state, the refrigerant in the system is all in liquid state with a dryness fraction close to 0. Therefore, the overall mass equation is:

[0099]

[0100] Under superheated conditions, the refrigerant in the system is entirely in liquid state with a dryness fraction close to 1. Therefore, the overall mass equation is:

[0101] m total =V total ·ρ gas .

[0102] Step 3: Output a warning signal based on the current refrigerant balance, leakage trend, and real-time leakage rate of the refrigerant; wherein the warning signal includes: low pressure warning and the remaining time for triggering the low pressure warning.

[0103] S31. Calculate the fitting leakage trend:

[0104] S311. Calculate and save the daily, weekly, and monthly leakage rates of the refrigerant;

[0105] In the calculation of each leakage rate, the initial charge amount is not relied upon. Instead, the leakage rate is calculated by comparing the results of each measurement with the previous measurement. This avoids the situation where the air conditioning system does not leak in the early stage of operation but leaks later, resulting in a larger actual leakage rate. However, if the calculation starts from the initial time, the calculated leakage rate will be smaller, thus prolonging the alarm time and leading to a lack of alarm effectiveness.

[0106] To improve the reliability of the leakage rate calculation, the system uses the sliding window method to calculate the average leakage rate. By using the sliding window method, the system can effectively smooth the leakage rate data, reduce the impact of daily data fluctuations on the results, and thus improve the reliability of the leakage rate calculation.

[0107] By calculating daily, weekly, and monthly leakage rates separately, short-term and long-term leakage trends can be better balanced, reducing detection and calculation biases caused by micro-leaks in the system and thus improving system reliability. If data is less than one week or one month's worth, the existing data is used to calculate an average value to ensure the reliability of the calculation.

[0108] The results of each calculation are recorded to a file, and this historical data is read in subsequent calculations to ensure the continuity and reliability of the leakage rate calculation. By recording and reading historical data, the system can maintain data continuity and avoid inaccurate results due to errors in a single calculation.

[0109] S312. Use the exponential fitting method to fit the saved leakage rate data and obtain the corresponding predicted trend of leakage rate.

[0110] By plotting scatter plots and fitted curves of leakage rates, leakage trends can be visually displayed, including daily, weekly, and monthly leakage rates, helping users better understand the system's operation. If the daily leakage trend gradually exceeds the weekly or monthly leakage trend, the accelerating leakage rate can be observed more clearly. Visualizing leakage trends allows users to intuitively see the changing trends of the leakage rate, promptly detect anomalies, and provide early warnings and interventions.

[0111] To predict the time it takes to reach the alarm threshold, the system uses an exponential fitting method to fit historical leakage rate data and predict future leakage rate trends. Through data fitting and trend prediction, future leakage trends can be accurately predicted, providing the remaining time to trigger a low-pressure alarm calculated based on daily, weekly, and monthly leakage rates. This allows for early warning and intervention, improving the reliability of the air conditioning unit.

[0112] Example 2

[0113] This embodiment will be based on Figure 2 and Figure 3 A refrigerant leak warning system 100 and an electronic device 200 are described.

[0114] For early warning system 100, refer to... Figure 2 As shown, it includes:

[0115] The acquisition module 110 is used to collect temperature and pressure data from the air conditioning unit.

[0116] The margin calculation module 120 is communicatively connected to the data acquisition module. The margin calculation module is used to calculate the refrigerant margin based on the temperature data and pressure data.

[0117] The leakage warning module 130 is used to output a warning signal based on the current refrigerant balance, the fitted leakage trend, and the real-time leakage rate of the refrigerant.

[0118] Communication module 140 is used to communicate with external devices.

[0119] Reference Figure 1 As shown, a display module 150 is also provided for displaying alarm information.

[0120] It should be understood that the early warning system 100 here is embodied in the form of a functional module. The term "module" here can refer to application-specific integrated circuits (ASICs), electronic circuits, processors (e.g., shared processors, proprietary processors, or group processors, etc.) and memories for executing one or more software or firmware programs, integrated logic circuits, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the early warning system 100 may be specifically the electronic device 200 in the above embodiments, or the functions of the electronic device 200 in the above embodiments may be integrated into the early warning system 100. The early warning system 100 may be used to execute the various processes and / or steps corresponding to the electronic device 200 in the above method embodiments; to avoid repetition, these will not be described again here.

[0121] The aforementioned early warning system 100 has the function of implementing the corresponding steps performed by the electronic device 200 of the early warning method in Embodiment 1; the aforementioned function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned function. For example, the aforementioned acquisition module can be a communication interface, such as a transceiver interface.

[0122] In the embodiments of this application, Figure 2 The margin calculation module 120 and the leakage warning module 130 can also be chips or chip systems, such as system on chip (SoC).

[0123] Reference Figure 3 As shown, in this embodiment, an electronic device 200 is provided, including:

[0124] Processor 210, and memory 220 and transceiver 230 communicatively connected to the processor;

[0125] The memory 220 stores computer-executed instructions; the transceiver 230 is used for sending and receiving data.

[0126] The processor 210 executes the computer execution instructions stored in the memory 220 to implement the early warning method in Embodiment 1.

[0127] It should be understood that the electronic device 200 can be used to perform the corresponding steps and / or processes in the above method embodiments. Optionally, the memory 220 may include read-only memory and random access memory, and provide instructions and data to the processor. A portion of the memory 220 may also include non-volatile random access memory. For example, the memory 220 may also store device type information. The processor 210 can be used to execute instructions stored in the memory 220, and when the processor 210 executes the instructions, the processor 210 can perform the corresponding steps and / or processes in the above method embodiments.

[0128] It should be understood that, in the embodiments of this application, the processor 210 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0129] In implementation, each step of the above method can be completed by the integrated logic circuitry of the hardware in the processor 210 or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly embodied in the execution by the hardware processor, or by a combination of hardware and software modules in the processor 210. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor executes the instructions in the memory, combining them with its hardware to complete the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0130] Example 3

[0131] In this embodiment, a computer-readable storage medium is provided, characterized in that,

[0132] The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the early warning method in Embodiment 1.

[0133] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0134] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0135] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0136] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0137] The technical solution of the present invention has the following technical effects compared with the prior art:

[0138] The refrigerant balance calculation scheme provided by this invention has high calculation accuracy and reliable data. It can monitor the refrigerant level in the system and detect abnormalities in a timely manner without relying on big data or historical data. At the same time, it can provide accurate early warning, avoid system failures, ensure the normal operation of the air conditioning unit, and improve system reliability.

[0139] In addition, this method can also be used to realize volume calculation, leakage rate calculation and fault prediction functions, and comprehensively monitor the system status; it has wide applications.

[0140] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0141] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A refrigerant leakage warning method characterized by comprising: The method comprises the following steps: Collecting temperature data and pressure data of the air conditioning unit and preprocessing the data; Using the temperature data and pressure data and combining with a physical property database to calculate the refrigerant residual amount; Outputting a warning signal according to the current refrigerant residual amount, the leakage trend and the real-time leakage rate of the refrigerant; The warning signal comprises a low-pressure warning and a remaining time for triggering the low-pressure warning; The calculation of the refrigerant residual amount comprises the following steps: Determining the type of the refrigerant; Obtaining dryness data from the temperature data and pressure data; the dryness data refers to the mass percentage of dry steam contained in each kilogram of wet steam; The calculation formula of the dryness data is: ； where x is the dryness data, m gas is the total mass of gas phase refrigerant within the system; m liqud is the total mass of liquid phase refrigerant within the system; m total is the total mass of refrigerant within the system, m total = m gas + m liqud ; Obtaining gas phase density, liquid phase density and volume parameters; the gas phase density is the density of the gas phase refrigerant, and the liquid phase density is the density of the liquid phase refrigerant; both the gas phase density and the liquid phase density are obtained by calling the physical property database; the volume parameters are obtained by calculating the known charging amount or by system setting; The gas-liquid two-phase mass ratio is ； The volume parameters are calculated by the mass calculation formula: ； where V total is the system volume, V total = V gas + V liqud , V liqud is the total volume of liquid phase refrigerant in the system, V gas is the total volume of gas phase refrigerant in the system; p liqud is the density of the liquid phase refrigerant; and p gas is the density of the gas phase refrigerant. Combining the equations m gas = V gas × ρ gas and m liqud = V liqud × ρ liqud ; the total mass in the system, i.e., the calculation equation for the refrigerant residual amount, is arranged as 。 2. The refrigerant leakage warning method according to claim 1, wherein: The fitting process of the leakage trend comprises: Calculating and saving the daily leakage rate, the weekly leakage rate and the monthly leakage rate of the refrigerant; Using an exponential fitting method to fit the saved leakage rate data and obtaining a predicted trend of the corresponding leakage rate.

3. The refrigerant leakage warning method according to claim 1, wherein: The calculation process of the refrigerant residual amount further comprises: When the called dryness data is abnormal, determining whether the refrigerant is in a pure liquid phase state or a pure gas phase state by comparing the pressure data with the saturation pressure of the current temperature.

4. The refrigerant leakage warning method according to claim 1, wherein: The temperature data and pressure data are measured by temperature sensors and pressure sensors in the shutdown state of the air conditioning system; the preprocessing of the temperature data and pressure data comprises: Using a Kalman filter algorithm to clean and filter the data collected by the sensors; Using a moving average method to smooth the filtered data.

5. A refrigerant leakage warning system characterized by comprising: To implement the method according to any one of claims 1-4, comprising: An acquisition module for collecting temperature data and pressure data of the air conditioning unit; A residual amount calculation module in communication connection with the acquisition module, the residual amount calculation module being configured to calculate a refrigerant residual amount according to the temperature data and pressure data; A leakage warning module configured to output a warning signal according to the current refrigerant residual amount, a fitted leakage trend and a real-time leakage rate of the refrigerant; A communication module configured to communicate with an external device.

6. An electronic device, comprising: Comprising: A processor, a memory and a transceiver in communication connection with the processor; The memory stores computer execution instructions; the transceiver is configured to receive and transmit data; The processor executes the computer execution instructions stored in the memory to implement the method according to any one of claims 1-4.

7. A computer readable storage medium, comprising: The computer readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the method according to any one of claims 1-4.

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