Method and device for determining lack of refrigerant of vehicle air conditioner, and vehicle

Abstract

This application provides a method, apparatus, and vehicle for determining refrigerant insufficiency in a vehicle air conditioner. The method includes: controlling the vehicle air conditioner to enter a cooling mode when the outside temperature is higher than the inside temperature, where the outside temperature is the ambient temperature outside the vehicle and the inside temperature is the ambient temperature inside the vehicle; acquiring superheat, saturation temperature difference, the opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree when the vehicle air conditioner has been running in cooling mode for a first predetermined duration, where the saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature; and determining that the vehicle air conditioner has refrigerant insufficiency when at least two of the superheat, saturation temperature difference, electronic expansion valve opening degree, and subcooling degree are within their corresponding predetermined ranges. This solves the problem of frequent misjudgments caused by relying on experience to determine refrigerant insufficiency in the prior art.

Description

Technical Field

[0001] This invention relates to the field of vehicle air conditioning technology, and more specifically, to a method, apparatus, computer-readable storage medium, and vehicle for determining insufficient refrigerant in a vehicle air conditioning system. Background Technology

[0002] Bus air conditioners are prone to leakage due to large vibrations during operation. Traditionally, when the unit fails to operate normally, after-sales service relies on experience to make a judgment, which is prone to misjudgment and incorrect diagnosis. In order to ensure that the unit can quickly enter self-judgment during subsequent maintenance, there is an urgent need for a bus air conditioner refrigerant insufficient judgment logic protection method to solve the above problems. Summary of the Invention

[0003] The main objective of this application is to provide a method, apparatus, computer-readable storage medium, and vehicle for determining refrigerant deficiency in vehicle air conditioning, so as to at least solve the problem of frequent misjudgments caused by relying on experience to determine refrigerant deficiency in vehicle air conditioning in the prior art.

[0004] To achieve the above objectives, according to one aspect of this application, a method for determining refrigerant deficiency in a vehicle air conditioner is provided, comprising: a control step, wherein when the outside temperature is greater than the inside temperature, the vehicle air conditioner is controlled to enter a cooling mode, wherein the outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located; an acquisition step, wherein when the vehicle air conditioner has been running in the cooling mode for a first predetermined duration, superheat, saturation temperature difference, the opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling are acquired, wherein the saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature; and when at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within corresponding predetermined ranges, the refrigerant deficiency of the vehicle air conditioner is determined.

[0005] Optionally, after acquiring the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: if at most one of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling is within the corresponding predetermined range, repeating the control step and the acquisition step at least once in sequence until at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within the corresponding predetermined range or the repetition number reaches a predetermined number.

[0006] Optionally, the process of obtaining the superheat includes: obtaining the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator, and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator; and calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0007] Optionally, the process of obtaining the subcooling degree includes: obtaining the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser; determining the condensing temperature corresponding to the condensing pressure according to a first saturation temperature mapping relationship, wherein the condensing temperature is the saturation temperature at which refrigerant vapor condenses under the condensing pressure, and the first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined through calibration tests; and calculating the difference between the condensing temperature and the condenser outlet temperature to obtain the subcooling degree.

[0008] Optionally, the process of obtaining the saturation temperature difference includes: obtaining the evaporation pressure of the evaporator and the target saturation temperature; determining the evaporation temperature corresponding to the evaporation pressure according to the saturation temperature mapping relationship, wherein the evaporation temperature is the saturation temperature of refrigerant evaporation at the evaporation pressure, and the saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test; calculating the difference between the evaporation temperature and the target saturation temperature to obtain the saturation temperature difference.

[0009] Optionally, before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, the method further includes: when the vehicle air conditioner operates in the cooling mode for a second predetermined duration, adjusting the operating frequency of the vehicle air conditioner to a predetermined frequency range until the vehicle air conditioner operates in the cooling mode for a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

[0010] Optionally, before controlling the vehicle air conditioner to enter the cooling mode, the method further includes: acquiring the outside temperature and the inside temperature; and determining that the outside temperature is greater than the inside temperature when the inside temperature is within a first predetermined temperature range and the outside temperature is within a second predetermined temperature range, wherein the lowest temperature of the second predetermined temperature range is greater than the highest temperature of the first predetermined temperature range.

[0011] According to another aspect of this application, a device for determining refrigerant deficiency in a vehicle air conditioner is provided, comprising: a control unit for executing a control step of controlling the vehicle air conditioner to enter a cooling mode when the outside temperature is greater than the inside temperature, wherein the outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located; an acquisition unit for executing an acquisition step of acquiring superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree when the vehicle air conditioner has been in the cooling mode for a first predetermined duration, wherein the saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and a target saturation temperature; and a determination unit for determining that the refrigerant of the vehicle air conditioner is insufficient when at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling degree are within corresponding predetermined ranges.

[0012] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0013] According to another aspect of this application, a vehicle is provided, comprising: an in-vehicle air conditioner, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of the methods described.

[0014] Applying the technical solution of this application, in the above-mentioned method for determining insufficient refrigerant in a vehicle air conditioner, firstly, a control step is executed: when the outside temperature is greater than the inside temperature, the vehicle air conditioner is controlled to enter a cooling mode, where the outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located; then, an acquisition step is executed: when the vehicle air conditioner has been running in the cooling mode for a first predetermined duration, superheat, saturation temperature difference, the opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling are acquired, where the saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature; finally, if at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within their corresponding predetermined ranges, it is determined that the refrigerant in the vehicle air conditioner is insufficient. This method determines the refrigerant deficiency of the vehicle air conditioner by measuring superheat, saturation temperature difference, opening degree of electronic expansion valve, and subcooling degree after the vehicle air conditioner has entered cooling mode and has been running for a first predetermined period of time. If at least two of the corresponding conditions are met, the method can accurately determine the refrigerant deficiency of the air conditioner and solve the problem of frequent misjudgments caused by relying on experience to determine the refrigerant deficiency of the vehicle air conditioner in the existing technology. Attached Figure Description

[0015] Figure 1 A hardware structure block diagram of a mobile terminal for performing a method for determining insufficient refrigerant in a vehicle air conditioner, according to an embodiment of this application, is shown.

[0016] Figure 2 A flowchart illustrating a method for determining insufficient refrigerant in a vehicle air conditioner according to an embodiment of this application is shown.

[0017] Figure 3 A flowchart illustrating another method for determining refrigerant deficiency in a vehicle air conditioner according to an embodiment of this application is shown.

[0018] Figure 4 A structural block diagram of a device for determining insufficient refrigerant in a vehicle air conditioner according to an embodiment of this application is shown. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] As described in the background section, the prior art relies on experience to determine the refrigerant deficiency of a vehicle air conditioner, which often leads to misjudgments. To solve this problem, embodiments of this application provide a method, apparatus, computer-readable storage medium, and vehicle for determining the refrigerant deficiency of a vehicle air conditioner.

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0024] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a method of determining insufficient refrigerant in a vehicle air conditioner according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0025] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0026] This embodiment provides a method for determining insufficient refrigerant in a vehicle air conditioner running on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0027] Figure 2 This is a flowchart of a method for determining insufficient refrigerant in a vehicle air conditioner according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0028] Step S201, control step: when the outside temperature is higher than the inside temperature, control the vehicle air conditioner to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located.

[0029] Specifically, in the test environment, the outside temperature of the vehicle is ensured to be higher than the inside temperature of the vehicle so that the vehicle air conditioner can enter the normal cooling mode, eliminating the influence of natural cooling on the cooling operation and avoiding inaccurate judgment of insufficient refrigerant due to low refrigerant demand in the cooling operation.

[0030] Step S202, acquisition step: when the vehicle air conditioner has been running in the above-mentioned cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner and the subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature.

[0031] Specifically, a suitable first predetermined duration is set so that when the vehicle air conditioner operates in cooling mode for the first predetermined duration, the vehicle air conditioner operates stably, reducing the impact of operational instability on parameters such as superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, thereby further ensuring the accuracy of refrigerant deficiency judgment.

[0032] Step S203: If at least two of the above-mentioned superheat, the above-mentioned saturation temperature difference, the opening degree of the above-mentioned electronic expansion valve and the above-mentioned subcooling are within the corresponding predetermined range, it is determined that the refrigerant of the vehicle air conditioner is insufficient.

[0033] Specifically, the four indicators of superheat, saturation temperature difference, electronic expansion valve opening, and subcooling all have predetermined ranges for indicating refrigerant insufficiency. Due to the possibility of being affected by accidental factors, the error rate of determining refrigerant insufficiency based on a single indicator reaching its corresponding predetermined range is relatively high. Therefore, at least two indicators must be within their corresponding predetermined ranges to determine that the vehicle air conditioner is running out of refrigerant. Of course, to further improve the accuracy of refrigerant insufficiency judgment, it is also possible to determine that the vehicle air conditioner is running out of refrigerant only when all four indicators are within their corresponding predetermined ranges.

[0034] In the above-mentioned method for determining insufficient refrigerant in a vehicle air conditioner, firstly, a control step is executed: when the outside temperature is higher than the inside temperature, the vehicle air conditioner is controlled to enter a cooling mode. The outside temperature refers to the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature refers to the ambient temperature inside the vehicle where the vehicle air conditioner is located. Then, an acquisition step is executed: when the vehicle air conditioner has been running in the cooling mode for a first predetermined duration, superheat, saturation temperature difference, the opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature. Finally, if at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling are within their respective predetermined ranges, it is determined that the refrigerant in the vehicle air conditioner is insufficient. This method determines the refrigerant deficiency of the vehicle air conditioner by measuring superheat, saturation temperature difference, opening degree of electronic expansion valve, and subcooling degree after the vehicle air conditioner has entered cooling mode and has been running for a first predetermined period of time. If at least two of the corresponding conditions are met, the method can accurately determine the refrigerant deficiency of the air conditioner and solve the problem of frequent misjudgments caused by relying on experience to determine the refrigerant deficiency of the vehicle air conditioner in the existing technology.

[0035] In addition, in practical applications, it is necessary to conduct a detailed investigation of the detection time or set temperature at each stage, as there are inconsistencies between different vehicle models. To obtain a more reasonable value, it is necessary to accurately control various situations and avoid air conditioning misjudgments caused by unreasonable parameter settings, such as the preset range.

[0036] To further improve the accuracy of refrigerant shortage detection, in one optional embodiment, after obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the aforementioned vehicle air conditioner, and subcooling, the method further includes:

[0037] Step S301: When at most one of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling is within the corresponding predetermined range, the control step and the acquisition step are repeated at least once in sequence until at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within the corresponding predetermined range or the number of repetitions reaches a predetermined number.

[0038] Specifically, if the four indicators of superheat, saturation temperature difference, electronic expansion valve opening and subcooling are all outside the corresponding predetermined range, or only one indicator is within the corresponding predetermined range, it is temporarily assumed that the vehicle air conditioner is not short of refrigerant. The next test is then conducted, and this process is repeated multiple times until at least two indicators are within the corresponding predetermined range, indicating that the vehicle air conditioner is short of refrigerant. Alternatively, if the number of repetitions reaches the predetermined number, it can be determined that the vehicle air conditioner is not short of refrigerant.

[0039] To facilitate the measurement of superheat, in one optional embodiment, the process of obtaining the superheat includes:

[0040] Step S401: Obtain the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator, and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator.

[0041] Step S402: Calculate the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0042] Specifically, superheat is the difference between the saturation temperature of the refrigerant corresponding to the exhaust pressure and the exhaust temperature. The refrigerant vapor at the evaporator inlet is saturated vapor, that is, the evaporator inlet temperature Thg is the saturation temperature of the refrigerant corresponding to the exhaust pressure. Therefore, by setting temperature sensors at the evaporator inlet and evaporator outlet respectively, the evaporator inlet temperature Thg and the evaporator outlet temperature Thl can be measured. The superheat can be obtained based on the difference between the evaporator inlet temperature Thg and the evaporator outlet temperature Thl, which simplifies the measurement method of superheat.

[0043] To facilitate the measurement of subcooling, in one optional implementation, the process of obtaining the aforementioned subcooling includes:

[0044] Step S501: Obtain the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser.

[0045] Step S502: Determine the condensing temperature corresponding to the condensing pressure according to the first saturation temperature mapping relationship. The condensing temperature is the saturation temperature of refrigerant vapor condensation under the condensing pressure. The first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test.

[0046] Step S503: Calculate the difference between the condensation temperature and the condenser outlet temperature to obtain the subcooling.

[0047] Specifically, pressure and temperature sensors are used to collect the condensing pressure and condenser outlet temperature of the condenser, respectively. The mapping relationship between the condensing pressure and the condensing temperature is determined through calibration tests, and the mapping relationship of the first saturation temperature can be obtained. For example, a mapping table of condensing pressure and condensing temperature can be used to determine the condensing temperature corresponding to the condensing pressure. The difference between the condensing temperature and the condenser outlet temperature can then be calculated to obtain the subcooling. The subcooling can be obtained by simple calculation using the measurement values ​​of the two sensors, which is convenient and concise.

[0048] To facilitate the measurement of the supersaturated temperature difference, in one optional embodiment, the process of obtaining the above-mentioned saturated temperature difference includes:

[0049] Step S601: Obtain the evaporation pressure of the evaporator and the target saturation temperature.

[0050] Step S602: Determine the evaporation temperature corresponding to the evaporation pressure according to the second saturation temperature mapping relationship. The evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure. The saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test.

[0051] Step S603: Calculate the difference between the evaporation temperature and the target saturation temperature to obtain the saturation temperature difference.

[0052] Specifically, a low saturation temperature makes it difficult for the refrigerant to evaporate and absorb heat, resulting in poor cooling performance. Therefore, setting a suitable target saturation temperature ensures a good cooling effect. By measuring the evaporation pressure of the evaporator using a pressure sensor and determining the mapping relationship between evaporation pressure and evaporation temperature based on calibration tests, the corresponding saturation temperature is determined as the evaporation temperature. The difference between the evaporation temperature and the target saturation temperature is then calculated to obtain the saturation temperature difference. The saturation temperature difference can be obtained through simple calculations using the pressure sensor measurements, which is convenient and straightforward.

[0053] To further improve the accuracy of refrigerant shortage detection, in an optional embodiment, before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the aforementioned vehicle air conditioner, and subcooling, the method further includes:

[0054] Step S701: When the vehicle air conditioner has been in the cooling mode for a second predetermined duration, the operating frequency of the vehicle air conditioner is adjusted to a predetermined frequency range until the vehicle air conditioner has been in the cooling mode for a first predetermined duration, and the difference between the first predetermined duration and the second predetermined duration is greater than or equal to the third operating duration.

[0055] Specifically, at this time, the air conditioner starts running in cooling mode. After running for a second predetermined time T1 seconds, the operating frequency of the air conditioner compressor is adjusted to meet the condition that ft1 ≤ compressor frequency ≤ ft2, for example, 50HZ ≤ compressor frequency ≤ 80HZ. This step is to ensure that most or all of the refrigerant in the system participates in the system operation, avoid misjudgment caused by inappropriate frequency, and ensure that the compressor operating frequency is within the range of ft1 ≤ compressor frequency ≤ ft2. After running for T2 minutes, the first predetermined time is reached, so that the air conditioning system parameters tend to stabilize. For example, T1 is 180s and T2 is 30min.

[0056] To further improve the accuracy of refrigerant shortage detection, in one optional implementation, before controlling the vehicle air conditioner to enter cooling mode, the method further includes:

[0057] Step S801: Obtain the above-mentioned outside temperature and inside temperature of the vehicle;

[0058] Step S802: When the interior temperature is within a first predetermined temperature range and the exterior temperature is within a second predetermined temperature range, it is determined that the exterior temperature is greater than the interior temperature, and the lowest temperature of the second predetermined temperature range is greater than the highest temperature of the first predetermined temperature range.

[0059] Specifically, move the vehicle with the air conditioning on to a temperature-adjustable environment. First, adjust the interior and exterior ambient temperatures to bring them to the set range, satisfying Tin1 ≤ interior ambient temperature ≤ Tin2. The interior temperature can be set according to specific parameters, such as Tin1 = 20℃, Tin2 = 30℃, Tin1 = 30℃, and Tin2 = 38℃. This avoids inaccurate judgments of insufficient refrigerant in extreme environments.

[0060] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the method for determining insufficient refrigerant in vehicle air conditioning will be described in detail below with reference to specific embodiments.

[0061] This embodiment relates to a specific method for determining insufficient refrigerant in a vehicle air conditioner, such as... Figure 3 As shown, it includes the following steps:

[0062] Step S1: First, adjust the interior and exterior ambient temperatures to reach the set range, i.e., satisfying Tin1 ≤ interior ambient temperature ≤ Tin2, and Tout1 ≤ exterior ambient temperature ≤ Tout2. For example, if Tin1 = 20℃, Tin2 = 30℃, Tout1 = 30℃, and Tout2 = 38℃, then 20℃ ≤ interior ambient temperature ≤ 30℃, and 30℃ < exterior ambient temperature ≤ 38℃.

[0063] Step S2: When the working conditions inside and outside the vehicle reach the required range after T1 seconds, the air conditioner is turned on and runs in cooling mode. After running for T2 seconds, the operating frequency of the air conditioner compressor is adjusted to meet the requirement of 50HZ≤compressor frequency≤80HZ. T1=2 seconds, T2=180 seconds.

[0064] Step S3: Ensure the compressor operating frequency is within the range of ft1 ≤ compressor frequency ≤ ft2, i.e., 50Hz ≤ compressor frequency ≤ 80Hz. After running for T3 minutes and waiting for the system parameters to stabilize, collect the evaporator inlet temperature Thg and the evaporator outlet temperature Thl, calculate the superheat SC = Thg - Thl, and calculate the value of superheat SC and SC1. Collect the evaporation temperature and the target saturation temperature, obtain the difference between the two, i.e., the saturation temperature difference, and calculate the value of saturation temperature difference and E1. Collect the opening value of the electronic expansion valve, calculate the opening value and PS, collect the condensing temperature and the condenser outlet temperature, obtain the subcooling, and calculate the difference in subcooling and SH1. T3 = 30 minutes.

[0065] Step S4: According to the calculated values ​​above, if the superheat < SC1, saturation temperature difference < E1, electronic expansion valve opening ≥ PS1, and subcooling ≥ SH1, and all four conditions meet the above settings, it can be determined that the bus air conditioning refrigerant is insufficient. The display screen will show the fault code to guide the after-sales service for repair. Among them, SC1 = 5℃, E1 = -5℃, PS1 = 450B, and SH1 = 10℃.

[0066] Step S5: If the superheat < SC1, saturation temperature difference < E1, electronic expansion valve opening ≥ PS1, and subcooling ≥ SH1, and any one of the above four conditions is not met, it is necessary to return to step S2 for re-judgment.

[0067] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0068] This application also provides a device for determining insufficient refrigerant in a vehicle air conditioner. It should be noted that this device can be used to execute the method for determining insufficient refrigerant in a vehicle air conditioner provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0069] The following describes the device for determining insufficient refrigerant in a vehicle air conditioner provided in the embodiments of this application.

[0070] Figure 4 This is a structural block diagram of a device for determining insufficient refrigerant in a vehicle air conditioner according to an embodiment of this application. Figure 4As shown, the device includes:

[0071] The control unit 10 is used to execute control steps, and when the outside temperature is higher than the inside temperature, it controls the vehicle air conditioner to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located.

[0072] Specifically, in the test environment, the outside temperature of the vehicle is ensured to be higher than the inside temperature of the vehicle so that the vehicle air conditioner can enter the normal cooling mode, eliminating the influence of natural cooling on the cooling operation and avoiding inaccurate judgment of insufficient refrigerant due to low refrigerant demand in the cooling operation.

[0073] The acquisition unit 20 is used to perform the acquisition step. When the vehicle air conditioner is in the cooling mode for a first predetermined time, it acquires the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature.

[0074] Specifically, a suitable first predetermined duration is set so that when the vehicle air conditioner operates in cooling mode for the first predetermined duration, the vehicle air conditioner operates stably, reducing the impact of operational instability on parameters such as superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, thereby further ensuring the accuracy of refrigerant deficiency judgment.

[0075] The determining unit 30 is used to determine that the refrigerant of the vehicle air conditioner is insufficient when at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within the corresponding predetermined range.

[0076] Specifically, the four indicators of superheat, saturation temperature difference, electronic expansion valve opening, and subcooling all have predetermined ranges for indicating refrigerant insufficiency. Due to the possibility of being affected by accidental factors, the error rate of determining refrigerant insufficiency based on a single indicator reaching its corresponding predetermined range is relatively high. Therefore, at least two indicators must be within their corresponding predetermined ranges to determine that the vehicle air conditioner is running out of refrigerant. Of course, to further improve the accuracy of refrigerant insufficiency judgment, it is also possible to determine that the vehicle air conditioner is running out of refrigerant only when all four indicators are within their corresponding predetermined ranges.

[0077] In the aforementioned device for determining insufficient refrigerant in a vehicle air conditioner, the control unit executes a control step, controlling the vehicle air conditioner to enter a cooling mode when the outside temperature is higher than the inside temperature. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located. The acquisition unit executes an acquisition step, acquiring superheat, saturation temperature difference, the opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling when the vehicle air conditioner has been running in the cooling mode for a first predetermined time. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature. The determination unit determines that the refrigerant in the vehicle air conditioner is insufficient when at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling are within their respective predetermined ranges. After the vehicle air conditioner has been running in cooling mode for a predetermined period of time, the device determines whether the refrigerant in the vehicle air conditioner is insufficient by measuring superheat, saturation temperature difference, opening degree of electronic expansion valve, and subcooling. If at least two of the corresponding conditions are met, the device can accurately determine whether the refrigerant in the vehicle air conditioner is insufficient, thus solving the problem of frequent misjudgments caused by relying on experience to determine the refrigerant in the vehicle air conditioner in the existing technology.

[0078] In addition, in practical applications, it is necessary to conduct a detailed investigation of the detection time or set temperature at each stage, as there are inconsistencies between different vehicle models. To obtain a more reasonable value, it is necessary to accurately control various situations and avoid air conditioning misjudgments caused by unreasonable parameter settings, such as the preset range.

[0079] To further improve the accuracy of refrigerant shortage detection, in one optional embodiment, the above-mentioned device further includes:

[0080] The repeating unit is configured to, after acquiring the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, sequentially repeat the control step and the acquisition step at least once, provided that at most one of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling degree is within the corresponding predetermined range, until at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling degree are within the corresponding predetermined range or the number of repetitions reaches a predetermined number.

[0081] Specifically, if the four indicators of superheat, saturation temperature difference, electronic expansion valve opening and subcooling are all outside the corresponding predetermined range, or only one indicator is within the corresponding predetermined range, it is temporarily assumed that the vehicle air conditioner is not short of refrigerant. The next test is then conducted, and this process is repeated multiple times until at least two indicators are within the corresponding predetermined range, indicating that the vehicle air conditioner is short of refrigerant. Alternatively, if the number of repetitions reaches the predetermined number, it can be determined that the vehicle air conditioner is not short of refrigerant.

[0082] To facilitate the measurement of superheat, in one optional embodiment, the acquisition unit includes:

[0083] The first acquisition module is used to acquire the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator, and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator.

[0084] The first calculation module is used to calculate the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0085] Specifically, superheat is the difference between the saturation temperature of the refrigerant corresponding to the exhaust pressure and the exhaust temperature. The refrigerant vapor at the evaporator inlet is saturated vapor, that is, the evaporator inlet temperature Thg is the saturation temperature of the refrigerant corresponding to the exhaust pressure. Therefore, by setting temperature sensors at the evaporator inlet and evaporator outlet respectively, the evaporator inlet temperature Thg and the evaporator outlet temperature Thl can be measured. The superheat can be obtained based on the difference between the evaporator inlet temperature Thg and the evaporator outlet temperature Thl, which simplifies the measurement method of superheat.

[0086] To facilitate the measurement of supercooling, in one optional embodiment, the acquisition unit further includes:

[0087] The second acquisition module is used to acquire the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser.

[0088] The first determining module is used to determine the condensing temperature corresponding to the condensing pressure according to the first saturation temperature mapping relationship. The condensing temperature is the saturation temperature at which the refrigerant vapor condenses under the condensing pressure. The first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test.

[0089] The second calculation module is used to calculate the difference between the condensation temperature and the condenser outlet temperature to obtain the subcooling.

[0090] Specifically, pressure and temperature sensors are used to collect the condensing pressure and condenser outlet temperature of the condenser, respectively. The mapping relationship between the condensing pressure and the condensing temperature is determined through calibration tests, and the mapping relationship of the first saturation temperature can be obtained. For example, a mapping table of condensing pressure and condensing temperature can be used to determine the condensing temperature corresponding to the condensing pressure. The difference between the condensing temperature and the condenser outlet temperature can then be calculated to obtain the subcooling. The subcooling can be obtained by simple calculation using the measurement values ​​of the two sensors, which is convenient and concise.

[0091] To facilitate the measurement of supersaturated temperature difference, in one optional embodiment, the acquisition unit further includes:

[0092] The third acquisition module is used to acquire the evaporation pressure of the evaporator and the target saturation temperature.

[0093] The second determining module is used to determine the evaporation temperature corresponding to the evaporation pressure according to the second saturation temperature mapping relationship. The evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure. The saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test.

[0094] The third calculation module is used to calculate the difference between the evaporation temperature and the target saturation temperature to obtain the saturation temperature difference.

[0095] Specifically, a low saturation temperature makes it difficult for the refrigerant to evaporate and absorb heat, resulting in poor cooling performance. Therefore, setting a suitable target saturation temperature ensures a good cooling effect. By measuring the evaporation pressure of the evaporator using a pressure sensor and determining the mapping relationship between evaporation pressure and evaporation temperature based on calibration tests, the corresponding saturation temperature is determined as the evaporation temperature. The difference between the evaporation temperature and the target saturation temperature is then calculated to obtain the saturation temperature difference. The saturation temperature difference can be obtained through simple calculations using the pressure sensor measurements, which is convenient and straightforward.

[0096] To further improve the accuracy of refrigerant shortage detection, in one optional embodiment, the above-mentioned device further includes:

[0097] The adjustment unit is used to adjust the operating frequency of the vehicle air conditioner to a predetermined frequency range before acquiring the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner and the subcooling degree, when the vehicle air conditioner has been in the cooling mode for a second predetermined duration, until the vehicle air conditioner has been in the cooling mode for a first predetermined duration, and the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

[0098] Specifically, at this time, the air conditioner starts running in cooling mode. After running for a second predetermined time T1 seconds, the operating frequency of the air conditioner compressor is adjusted to meet the condition that ft1 ≤ compressor frequency ≤ ft2, for example, 50HZ ≤ compressor frequency ≤ 80HZ. This step is to ensure that most or all of the refrigerant in the system participates in the system operation, avoid misjudgment caused by inappropriate frequency, and ensure that the compressor operating frequency is within the range of ft1 ≤ compressor frequency ≤ ft2. After running for T2 minutes, the first predetermined time is reached, so that the air conditioning system parameters tend to stabilize. For example, T1 is 180s and T2 is 30min.

[0099] To further improve the accuracy of refrigerant shortage detection, in one optional embodiment, the above-mentioned device further includes:

[0100] The fourth acquisition module is used to acquire the above-mentioned outside temperature and inside temperature before controlling the vehicle air conditioner to enter the cooling mode.

[0101] The third determining module is used to determine that, when the interior temperature is within a first predetermined temperature range and the exterior temperature is within a second predetermined temperature range, the exterior temperature is greater than the interior temperature, and the lowest temperature of the second predetermined temperature range is greater than the highest temperature of the first predetermined temperature range.

[0102] Specifically, move the vehicle with the air conditioning on to a temperature-adjustable environment. First, adjust the interior and exterior ambient temperatures to bring them to the set range, satisfying Tin1 ≤ interior ambient temperature ≤ Tin2. The interior temperature can be set according to specific parameters, such as Tin1 = 20℃, Tin2 = 30℃, Tin1 = 30℃, and Tin2 = 38℃. This avoids inaccurate judgments of insufficient refrigerant in extreme environments.

[0103] The aforementioned device for determining insufficient refrigerant in a vehicle air conditioner includes a processor and a memory. The control unit, acquisition unit, and determination unit are all stored as program units in the memory, and the processor executes these program units to achieve the corresponding functions. All of the above modules reside in the same processor; alternatively, the modules may be located in different processors in any combination.

[0104] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can address the problem of frequent misjudgments caused by relying on experience to determine refrigerant in vehicle air conditioning systems in existing technologies.

[0105] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0106] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the method for determining insufficient refrigerant in a vehicle air conditioner.

[0107] Specifically, methods for determining insufficient refrigerant in vehicle air conditioning systems include:

[0108] Step S201, control step: when the outside temperature is higher than the inside temperature, control the vehicle air conditioner to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located.

[0109] Specifically, in the test environment, the outside temperature of the vehicle is ensured to be higher than the inside temperature of the vehicle so that the vehicle air conditioner can enter the normal cooling mode, eliminating the influence of natural cooling on the cooling operation and avoiding inaccurate judgment of insufficient refrigerant due to low refrigerant demand in the cooling operation.

[0110] Step S202, acquisition step: when the vehicle air conditioner has been running in the above-mentioned cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner and the subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature.

[0111] Specifically, a suitable first predetermined duration is set so that when the vehicle air conditioner operates in cooling mode for the first predetermined duration, the vehicle air conditioner operates stably, reducing the impact of operational instability on parameters such as superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, thereby further ensuring the accuracy of refrigerant deficiency judgment.

[0112] Step S203: If at least two of the above-mentioned superheat, the above-mentioned saturation temperature difference, the opening degree of the above-mentioned electronic expansion valve and the above-mentioned subcooling are within the corresponding predetermined range, it is determined that the refrigerant of the vehicle air conditioner is insufficient.

[0113] Optionally, the four indicators of superheat, saturation temperature difference, electronic expansion valve opening, and subcooling all have predetermined ranges for characterizing refrigerant deficiency. Due to the possible influence of accidental factors, the error rate of determining refrigerant deficiency by a single indicator reaching the corresponding predetermined range is relatively high. Therefore, at least two indicators must be within the corresponding predetermined range to determine that the vehicle air conditioner is deficient in refrigerant. Of course, in order to further improve the accuracy of refrigerant deficiency judgment, the vehicle air conditioner can be determined to be deficient in refrigerant only when all four indicators are within the corresponding predetermined range.

[0114] Optionally, after obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S301, when at most one of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling is within the corresponding predetermined range, repeating the control step and the acquisition step at least once in sequence until at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling are within the corresponding predetermined range or the repetition number reaches a predetermined number.

[0115] Specifically, the process of obtaining the superheat includes: step S401, obtaining the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator; step S402, calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0116] Optionally, the process of obtaining the subcooling includes: step S501, obtaining the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser; step S502, determining the condensing temperature corresponding to the condensing pressure according to the first saturation temperature mapping relationship, wherein the condensing temperature is the saturation temperature at which the refrigerant vapor condenses under the condensing pressure, and the first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test; step S503, calculating the difference between the condensing temperature and the condenser outlet temperature to obtain the subcooling.

[0117] Optionally, the process of obtaining the above-mentioned saturation temperature difference includes: step S601, obtaining the evaporation pressure of the evaporator and the target saturation temperature; step S602, determining the evaporation temperature corresponding to the evaporation pressure according to the second saturation temperature mapping relationship, wherein the evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure, and the saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test; step S603, calculating the difference between the evaporation temperature and the target saturation temperature to obtain the above-mentioned saturation temperature difference.

[0118] Optionally, before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S701, when the vehicle air conditioner operates in the cooling mode for a second predetermined duration, adjusting the operating frequency of the vehicle air conditioner to a predetermined frequency range until the vehicle air conditioner operates in the cooling mode for a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

[0119] This invention provides a processor for running a program, wherein the program executes the method for determining insufficient refrigerant in a vehicle air conditioner.

[0120] Specifically, methods for determining insufficient refrigerant in vehicle air conditioning systems include:

[0121] Step S201, control step: when the outside temperature is higher than the inside temperature, control the vehicle air conditioner to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located.

[0122] Specifically, in the test environment, the outside temperature of the vehicle is ensured to be higher than the inside temperature of the vehicle so that the vehicle air conditioner can enter the normal cooling mode, eliminating the influence of natural cooling on the cooling operation and avoiding inaccurate judgment of insufficient refrigerant due to low refrigerant demand in the cooling operation.

[0123] Step S202, acquisition step: when the vehicle air conditioner has been running in the above-mentioned cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner and the subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature.

[0124] Specifically, a suitable first predetermined duration is set so that when the vehicle air conditioner operates in cooling mode for the first predetermined duration, the vehicle air conditioner operates stably, reducing the impact of operational instability on parameters such as superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, thereby further ensuring the accuracy of refrigerant deficiency judgment.

[0125] Step S203: If at least two of the above-mentioned superheat, the above-mentioned saturation temperature difference, the opening degree of the above-mentioned electronic expansion valve and the above-mentioned subcooling are within the corresponding predetermined range, it is determined that the refrigerant of the vehicle air conditioner is insufficient.

[0126] Optionally, the four indicators of superheat, saturation temperature difference, electronic expansion valve opening, and subcooling all have predetermined ranges for characterizing refrigerant deficiency. Due to the possible influence of accidental factors, the error rate of determining refrigerant deficiency by a single indicator reaching the corresponding predetermined range is relatively high. Therefore, at least two indicators must be within the corresponding predetermined range to determine that the vehicle air conditioner is deficient in refrigerant. Of course, in order to further improve the accuracy of refrigerant deficiency judgment, the vehicle air conditioner can be determined to be deficient in refrigerant only when all four indicators are within the corresponding predetermined range.

[0127] Optionally, after obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S301, when at most one of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling is within the corresponding predetermined range, repeating the control step and the acquisition step at least once in sequence until at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling are within the corresponding predetermined range or the repetition number reaches a predetermined number.

[0128] Specifically, the process of obtaining the superheat includes: step S401, obtaining the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator; step S402, calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0129] Optionally, the process of obtaining the subcooling includes: step S501, obtaining the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser; step S502, determining the condensing temperature corresponding to the condensing pressure according to the first saturation temperature mapping relationship, wherein the condensing temperature is the saturation temperature at which the refrigerant vapor condenses under the condensing pressure, and the first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test; step S503, calculating the difference between the condensing temperature and the condenser outlet temperature to obtain the subcooling.

[0130] Optionally, the process of obtaining the above-mentioned saturation temperature difference includes: step S601, obtaining the evaporation pressure of the evaporator and the target saturation temperature; step S602, determining the evaporation temperature corresponding to the evaporation pressure according to the second saturation temperature mapping relationship, wherein the evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure, and the saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test; step S603, calculating the difference between the evaporation temperature and the target saturation temperature to obtain the above-mentioned saturation temperature difference.

[0131] Optionally, before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S701, when the vehicle air conditioner operates in the cooling mode for a second predetermined duration, adjusting the operating frequency of the vehicle air conditioner to a predetermined frequency range until the vehicle air conditioner operates in the cooling mode for a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

[0132] This invention provides a vehicle, which includes an in-vehicle air conditioner, a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0133] Step S201, control step: when the outside temperature is higher than the inside temperature, control the vehicle air conditioner to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located.

[0134] Specifically, in the test environment, the outside temperature of the vehicle is ensured to be higher than the inside temperature of the vehicle so that the vehicle air conditioner can enter the normal cooling mode, eliminating the influence of natural cooling on the cooling operation and avoiding inaccurate judgment of insufficient refrigerant due to low refrigerant demand in the cooling operation.

[0135] Step S202, acquisition step: when the vehicle air conditioner has been running in the above-mentioned cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner and the subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature.

[0136] Specifically, a suitable first predetermined duration is set so that when the vehicle air conditioner operates in cooling mode for the first predetermined duration, the vehicle air conditioner operates stably, reducing the impact of operational instability on parameters such as superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, thereby further ensuring the accuracy of refrigerant deficiency judgment.

[0137] Step S203: If at least two of the above-mentioned superheat, the above-mentioned saturation temperature difference, the opening degree of the above-mentioned electronic expansion valve and the above-mentioned subcooling are within the corresponding predetermined range, it is determined that the refrigerant of the vehicle air conditioner is insufficient.

[0138] Optionally, the four indicators of superheat, saturation temperature difference, electronic expansion valve opening, and subcooling all have predetermined ranges for characterizing refrigerant deficiency. Due to the possible influence of accidental factors, the error rate of determining refrigerant deficiency by a single indicator reaching the corresponding predetermined range is relatively high. Therefore, at least two indicators must be within the corresponding predetermined range to determine that the vehicle air conditioner is deficient in refrigerant. Of course, in order to further improve the accuracy of refrigerant deficiency judgment, the vehicle air conditioner can be determined to be deficient in refrigerant only when all four indicators are within the corresponding predetermined range.

[0139] Optionally, after obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S301, when at most one of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling is within the corresponding predetermined range, repeating the control step and the acquisition step at least once in sequence until at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling are within the corresponding predetermined range or the repetition number reaches a predetermined number.

[0140] Specifically, the process of obtaining the superheat includes: step S401, obtaining the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator; step S402, calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0141] Optionally, the process of obtaining the subcooling includes: step S501, obtaining the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser; step S502, determining the condensing temperature corresponding to the condensing pressure according to the first saturation temperature mapping relationship, wherein the condensing temperature is the saturation temperature at which the refrigerant vapor condenses under the condensing pressure, and the first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test; step S503, calculating the difference between the condensing temperature and the condenser outlet temperature to obtain the subcooling.

[0142] Optionally, the process of obtaining the above-mentioned saturation temperature difference includes: step S601, obtaining the evaporation pressure of the evaporator and the target saturation temperature; step S602, determining the evaporation temperature corresponding to the evaporation pressure according to the second saturation temperature mapping relationship, wherein the evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure, and the saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test; step S603, calculating the difference between the evaporation temperature and the target saturation temperature to obtain the above-mentioned saturation temperature difference.

[0143] Optionally, before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S701, when the vehicle air conditioner operates in the cooling mode for a second predetermined duration, adjusting the operating frequency of the vehicle air conditioner to a predetermined frequency range until the vehicle air conditioner operates in the cooling mode for a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

[0144] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0145] Step S201, control step: when the outside temperature is higher than the inside temperature, control the vehicle air conditioner to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located.

[0146] Specifically, in the test environment, the outside temperature of the vehicle is ensured to be higher than the inside temperature of the vehicle so that the vehicle air conditioner can enter the normal cooling mode, eliminating the influence of natural cooling on the cooling operation and avoiding inaccurate judgment of insufficient refrigerant due to low refrigerant demand in the cooling operation.

[0147] Step S202, acquisition step: when the vehicle air conditioner has been running in the above-mentioned cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner and the subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature.

[0148] Specifically, a suitable first predetermined duration is set so that when the vehicle air conditioner operates in cooling mode for the first predetermined duration, the vehicle air conditioner operates stably, reducing the impact of operational instability on parameters such as superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, thereby further ensuring the accuracy of refrigerant deficiency judgment.

[0149] Step S203: If at least two of the above-mentioned superheat, the above-mentioned saturation temperature difference, the opening degree of the above-mentioned electronic expansion valve and the above-mentioned subcooling are within the corresponding predetermined range, it is determined that the refrigerant of the vehicle air conditioner is insufficient.

[0150] Optionally, the four indicators of superheat, saturation temperature difference, electronic expansion valve opening, and subcooling all have predetermined ranges for characterizing refrigerant deficiency. Due to the possible influence of accidental factors, the error rate of determining refrigerant deficiency by a single indicator reaching the corresponding predetermined range is relatively high. Therefore, at least two indicators must be within the corresponding predetermined range to determine that the vehicle air conditioner is deficient in refrigerant. Of course, in order to further improve the accuracy of refrigerant deficiency judgment, the vehicle air conditioner can be determined to be deficient in refrigerant only when all four indicators are within the corresponding predetermined range.

[0151] Optionally, after obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S301, when at most one of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling is within the corresponding predetermined range, repeating the control step and the acquisition step at least once in sequence until at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling are within the corresponding predetermined range or the repetition number reaches a predetermined number.

[0152] Specifically, the process of obtaining the superheat includes: step S401, obtaining the evaporator inlet temperature and the evaporator outlet temperature, wherein the evaporator inlet temperature is the temperature of the refrigerant at the inlet of the evaporator and the evaporator outlet temperature is the temperature of the refrigerant at the outlet of the evaporator; step S402, calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature to obtain the superheat.

[0153] Optionally, the process of obtaining the subcooling includes: step S501, obtaining the condensing pressure and condenser outlet temperature of the condenser of the vehicle air conditioner, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser; step S502, determining the condensing temperature corresponding to the condensing pressure according to the first saturation temperature mapping relationship, wherein the condensing temperature is the saturation temperature at which the refrigerant vapor condenses under the condensing pressure, and the first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test; step S503, calculating the difference between the condensing temperature and the condenser outlet temperature to obtain the subcooling.

[0154] Optionally, the process of obtaining the above-mentioned saturation temperature difference includes: step S601, obtaining the evaporation pressure of the evaporator and the target saturation temperature; step S602, determining the evaporation temperature corresponding to the evaporation pressure according to the second saturation temperature mapping relationship, wherein the evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure, and the saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test; step S603, calculating the difference between the evaporation temperature and the target saturation temperature to obtain the above-mentioned saturation temperature difference.

[0155] Optionally, before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling, the method further includes: step S701, when the vehicle air conditioner operates in the cooling mode for a second predetermined duration, adjusting the operating frequency of the vehicle air conditioner to a predetermined frequency range until the vehicle air conditioner operates in the cooling mode for a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

[0156] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0157] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0158] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0159] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0160] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0161] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0162] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0163] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0164] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0165] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0166] 1) In the method for determining insufficient refrigerant in the vehicle air conditioner of this application, firstly, a control step is performed: when the outside temperature is greater than the inside temperature, the vehicle air conditioner is controlled to enter the cooling mode. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located. Then, an acquisition step is performed: when the vehicle air conditioner has been running in the cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature. Finally, when at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve, and subcooling degree are within the corresponding predetermined range, it is determined that the refrigerant in the vehicle air conditioner is insufficient. This method determines the refrigerant deficiency of the vehicle air conditioner by measuring superheat, saturation temperature difference, opening degree of electronic expansion valve, and subcooling degree after the vehicle air conditioner has entered cooling mode and has been running for a first predetermined period of time. If at least two of the corresponding conditions are met, the method can accurately determine the refrigerant deficiency of the air conditioner and solve the problem of frequent misjudgments caused by relying on experience to determine the refrigerant deficiency of the vehicle air conditioner in the existing technology.

[0167] 2) In the refrigerant shortage determination device for vehicle air conditioning of this application, the control unit executes a control step, and controls the vehicle air conditioning to enter the cooling mode when the outside temperature is greater than the inside temperature. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioning is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioning is located. The acquisition unit executes an acquisition step, and acquires superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioning and subcooling degree when the vehicle air conditioning has been in the cooling mode for a first predetermined time. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioning and the target saturation temperature. The determination unit determines that the refrigerant of the vehicle air conditioning is insufficient when at least two of the superheat, saturation temperature difference, opening degree of the electronic expansion valve and subcooling degree are within the corresponding predetermined range. After the vehicle air conditioner has been running in cooling mode for a predetermined period of time, the device determines whether the refrigerant in the vehicle air conditioner is insufficient by measuring superheat, saturation temperature difference, opening degree of electronic expansion valve, and subcooling. If at least two of the corresponding conditions are met, the device can accurately determine whether the refrigerant in the vehicle air conditioner is insufficient, thus solving the problem of frequent misjudgments caused by relying on experience to determine the refrigerant in the vehicle air conditioner in the existing technology.

[0168] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for determining insufficient refrigerant in a vehicle air conditioner, characterized in that, include: The control steps involve controlling the vehicle air conditioner to enter cooling mode when the outside temperature is higher than the inside temperature. The outside temperature refers to the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature refers to the ambient temperature inside the vehicle where the vehicle air conditioner is located. In the acquisition step, when the vehicle air conditioner has been running in the cooling mode for a first predetermined time, the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling are acquired. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature. If at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within their respective predetermined ranges, it is determined that the refrigerant in the vehicle air conditioner is insufficient. Before obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, the method further includes: when the vehicle air conditioner operates in the cooling mode for a second predetermined duration, adjusting the operating frequency of the vehicle air conditioner to a predetermined frequency range until the vehicle air conditioner operates in the cooling mode for a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating duration.

2. The method according to claim 1, characterized in that, After obtaining the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, the method further includes: If at most one of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling is within the corresponding predetermined range, the control step and the acquisition step are repeated at least once in sequence until at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within the corresponding predetermined range or the number of repetitions reaches a predetermined number.

3. The method according to claim 1, characterized in that, The process of obtaining the superheat includes: The evaporator inlet temperature and evaporator outlet temperature are obtained, wherein the evaporator inlet temperature is the temperature of the refrigerant at the evaporator inlet, and the evaporator outlet temperature is the temperature of the refrigerant at the evaporator outlet; The superheat is obtained by calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

4. The method according to claim 1, characterized in that, The process of obtaining the supercooling includes: The condensing pressure and condenser outlet temperature of the vehicle air conditioner are obtained, wherein the condenser outlet temperature is the temperature of the refrigerant at the outlet of the condenser. The condensing temperature corresponding to the condensing pressure is determined according to the first saturation temperature mapping relationship. The condensing temperature is the saturation temperature at which the refrigerant vapor condenses under the condensing pressure. The first saturation temperature mapping relationship is the mapping relationship between the condensing pressure and the condensing temperature determined by calibration test. The difference between the condensation temperature and the condenser outlet temperature is calculated to obtain the subcooling.

5. The method according to claim 1, characterized in that, The process of obtaining the saturation temperature difference includes: Obtain the evaporation pressure of the evaporator and the target saturation temperature; The evaporation temperature corresponding to the evaporation pressure is determined according to the saturation temperature mapping relationship. The evaporation temperature is the saturation temperature of refrigerant evaporation under the evaporation pressure. The saturation temperature mapping relationship is the mapping relationship between the evaporation pressure and the evaporation temperature determined by calibration test. The difference between the evaporation temperature and the target saturation temperature is calculated to obtain the saturation temperature difference.

6. The method according to any one of claims 1 to 5, characterized in that, Before controlling the vehicle's air conditioning to enter cooling mode, the method further includes: Obtain the outside temperature and the inside temperature of the vehicle; When the interior temperature is within a first predetermined temperature range and the exterior temperature is within a second predetermined temperature range, it is determined that the exterior temperature is greater than the interior temperature, and the lowest temperature of the second predetermined temperature range is greater than the highest temperature of the first predetermined temperature range.

7. A device for determining insufficient refrigerant in a vehicle air conditioner, characterized in that, include: The control unit is used to execute control steps, such as controlling the vehicle air conditioner to enter the cooling mode when the outside temperature is higher than the inside temperature. The outside temperature is the ambient temperature outside the vehicle where the vehicle air conditioner is located, and the inside temperature is the ambient temperature inside the vehicle where the vehicle air conditioner is located. The acquisition unit is used to perform the acquisition step. When the vehicle air conditioner has been running in the cooling mode for a first predetermined time, it acquires the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling. The saturation temperature difference is the difference between the saturation temperature corresponding to the evaporation pressure of the evaporator of the vehicle air conditioner and the target saturation temperature. The determining unit is configured to determine that the refrigerant in the vehicle air conditioner is insufficient when at least two of the superheat, the saturation temperature difference, the opening degree of the electronic expansion valve, and the subcooling are within corresponding predetermined ranges. The device further includes an adjustment unit, configured to adjust the operating frequency of the vehicle air conditioner to a predetermined frequency range before acquiring the superheat, saturation temperature difference, opening degree of the electronic expansion valve of the vehicle air conditioner, and subcooling degree, when the operating time of the vehicle air conditioner in the cooling mode reaches a second predetermined duration, until the operating time of the vehicle air conditioner in the cooling mode reaches a first predetermined duration, wherein the difference between the first predetermined duration and the second predetermined duration is greater than or equal to a third operating time.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 6.

9. A vehicle, characterized in that, include: A vehicle air conditioner, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of claims 1 to 6.

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