Refrigerant leakage detection method, water chiller and computer readable storage medium

Abstract

The application discloses a refrigerant leakage detection method, a water chiller and a computer readable storage medium, and aims to improve the accuracy of water chiller leakage detection. The high-pressure side pressure of a compressor, the low-pressure side pressure of the compressor, the actual rotating speed of the compressor and the actual guide vane opening degree of the compressor can be obtained; according to the constraint relationship among the high-pressure side pressure, the low-pressure side pressure, the actual rotating speed and the actual guide vane opening degree, a first flow value of refrigerant flowing through the compressor is obtained; a second flow value of refrigerant flowing through a throttling device is obtained; because the refrigerant flow through the compressor and the refrigerant flow through the throttling device are equivalent when the system is balanced, whether the refrigerant leaks can be determined through the first flow value and the second flow value, and thus accurate detection of refrigerant leakage is realized.

Description

Technical Field

[0001] This invention relates to the field of chiller technology, specifically to a refrigerant leak detection method, a chiller, and a computer-readable storage medium. Background Technology

[0002] Chillers are widely used in air conditioning systems of large and medium-sized buildings due to their large capacity and high efficiency. However, long-term operation inevitably leads to performance degradation and malfunctions. For example, due to the numerous welding points and connections in chillers, refrigerant leaks are prone to occur after prolonged operation. Therefore, timely detection of refrigerant leaks is an urgent problem to be solved.

[0003] Under normal circumstances, the refrigerant leak can be determined by the temperature change pattern of the heat exchanger. For example, when the temperature difference between the inside and outside of the heat exchanger is greater than a certain threshold, it can be determined that there is a refrigerant leak.

[0004] However, the accuracy of the above-mentioned refrigerant leak detection methods is relatively low. Summary of the Invention

[0005] The main objective of this invention is to provide a refrigerant leak detection method, a chiller, and a computer-readable storage medium, aiming to improve the accuracy of refrigerant leak detection.

[0006] In the technical solution of this application, the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual speed of the compressor, and the actual guide vane opening of the compressor can be obtained; based on the constraint relationship between the high-pressure side pressure, the low-pressure side pressure, the actual speed, and the actual guide vane opening, a first flow rate value of the refrigerant flowing through the compressor is obtained; a second flow rate value of the refrigerant flowing through a throttling device is obtained, the throttling device being installed between the condenser and the evaporator; and whether the refrigerant is leaking is determined based on the first flow rate value and the second flow rate value.

[0007] In this application, since the refrigerant flow rate through the compressor and the refrigerant flow rate through the throttling device are equivalent when the system is balanced, the refrigerant leakage can be determined by the first flow rate value and the second flow rate value, thereby achieving accurate detection of refrigerant leakage.

[0008] Based on the above technical solution, the present invention can be further improved as follows:

[0009] Furthermore, determining whether refrigerant is leaking based on the first flow rate value and the second flow rate value includes: determining refrigerant leakage when the difference between the first flow rate value and the second flow rate value is greater than or equal to a first threshold; or determining that there is no refrigerant leakage when the difference between the first flow rate value and the second flow rate value is less than the first threshold.

[0010] Furthermore, determining refrigerant leakage when the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold includes: determining refrigerant leakage when the time during which the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold exceeds the second threshold.

[0011] Furthermore, based on the constraint relationship between the high-pressure side pressure, the low-pressure side pressure, the actual rotational speed, and the actual guide vane opening, the first flow rate value of the refrigerant flowing through the compressor is obtained, including: obtaining the target rotational speed and the target guide vane opening based on the compressor's preset third flow rate value and the ratio of the high-pressure side pressure to the low-pressure side pressure; wherein, the third flow rate value, the ratio, and the target rotational speed are in a corresponding relationship; the third flow rate value, the ratio, and the target guide vane opening are in a corresponding relationship; when the difference between the target rotational speed and the actual rotational speed is less than or equal to a third threshold, and the difference between the target guide vane opening and the actual guide vane opening is less than or equal to a fourth threshold, the third flow rate value is determined as the first flow rate value.

[0012] Furthermore, when the difference between the target speed and the actual speed is greater than the third threshold, and / or the difference between the target guide vane opening and the actual guide vane opening is greater than the fourth threshold, the third flow rate value is adjusted to obtain the adjusted third flow rate value; based on the compressor's preset third flow rate value and the ratio of high-pressure side pressure to low-pressure side pressure, the target speed and the target guide vane opening are obtained, including: based on the adjusted third flow rate value and the ratio of high-pressure side pressure to low-pressure side pressure, the target speed and the target guide vane opening are obtained.

[0013] Furthermore, the third flow rate value is the volumetric flow rate. Determining the third flow rate value as the first flow rate value includes: obtaining the mass flow rate corresponding to the third flow rate value based on the third flow rate value and the first density of the refrigerant when it flows through the compressor; wherein, the first density is obtained based on the low-pressure side pressure and the compressor suction temperature; and determining the mass flow rate as the first flow rate value.

[0014] Furthermore, obtaining the second flow rate value of the refrigerant flowing through the throttling device includes: obtaining the second flow rate value based on the high-pressure side pressure, the low-pressure side pressure, the second density of the refrigerant when flowing through the throttling device, the flow area of ​​the throttling device, and the flow coefficient of the throttling device; wherein, the second density is obtained based on the high-pressure side pressure and the inlet temperature of the throttling device.

[0015] Furthermore, there are multiple compressors and multiple throttling devices. Determining whether the refrigerant is leaking based on the first flow rate value and the second flow rate value includes: determining whether the refrigerant is leaking based on the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values.

[0016] Furthermore, based on the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values, it is determined whether the refrigerant is leaking, including: determining that the refrigerant is leaking when the difference between the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values ​​is greater than or equal to a fifth threshold; or determining that the refrigerant is not leaking when the difference between the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values ​​is less than the fifth threshold.

[0017] Furthermore, the method also includes: executing a preset maintenance procedure when a refrigerant leak is determined; wherein the maintenance procedure includes: a frequency reduction procedure or an automatic shutdown procedure.

[0018] Furthermore, the method also includes: when a refrigerant leak is determined, sending an indication message to an electronic device to indicate the refrigerant leak, so that the electronic device can provide a refrigerant leak warning based on the indication message.

[0019] Furthermore, when there are multiple throttling devices, they are connected in parallel between the condenser and the evaporator.

[0020] The present invention also provides a chiller for performing any of the methods described above.

[0021] The present invention also provides an electronic device, which includes a processor for executing any of the methods described above.

[0022] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements any of the methods described above.

[0023] This invention also provides a refrigerant leak detection system, including a chiller and electronic equipment. The chiller's processor acquires the high-pressure side pressure, low-pressure side pressure, actual compressor speed, and actual guide vane opening of the compressor, and then sends these data to the electronic equipment. The electronic equipment acquires the high-pressure side pressure, low-pressure side pressure, actual speed, and actual guide vane opening from the chiller. Based on the relationship between these parameters, the electronic equipment obtains a first flow rate value of the refrigerant flowing through the compressor. The electronic equipment also acquires a second flow rate value of the refrigerant flowing through a throttling device. Finally, the electronic equipment determines whether a refrigerant leak has occurred based on the first and second flow rate values. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 A scenario diagram provided for an embodiment of this application;

[0026] Figure 2 A schematic flowchart illustrating a refrigerant leak detection method provided in an embodiment of this application;

[0027] Figure 3 A schematic diagram of a process for obtaining a first flow rate value provided in an embodiment of this application;

[0028] Figure 4 A schematic flowchart of another refrigerant leak detection method provided in an embodiment of this application;

[0029] Figure 5 A schematic diagram of the structure of a chiller 500 provided in this application embodiment;

[0030] Figure 6 This is a schematic diagram of the structure of a refrigerant leak detection device 600 provided in an embodiment of this application;

[0031] Figure 7 This is a schematic diagram of the structure of a refrigerant leak detection system 700 provided in an embodiment of this application. Detailed Implementation

[0032] During the operation of a chiller, refrigerant leakage can lead to a series of problems, such as increased compressor energy consumption and reduced chiller system lifespan. Therefore, timely detection of refrigerant leakage is an urgent issue to be addressed.

[0033] In related technologies, refrigerant leakage can be determined by the temperature change pattern of the heat exchanger. For example, if the temperature difference between the inside and outside of the heat exchanger is greater than or equal to a certain threshold, it can be determined that there is a refrigerant leak; or, if the temperature difference between the inside and outside of the heat exchanger is less than a certain threshold, it can be determined that there is no refrigerant leak.

[0034] However, the causes of temperature changes in heat exchangers are complex and varied, including factors such as the cleanliness of the heat exchanger, fluid flow rate, and refrigerant leaks. Therefore, using the temperature difference between the inside and outside of the heat exchanger for refrigerant leak detection has low accuracy and is prone to false positives.

[0035] In view of this, embodiments of the present invention obtain the high-pressure side pressure, low-pressure side pressure, actual speed, and actual guide vane opening of the compressor; based on the constraint relationship between the high-pressure side pressure, low-pressure side pressure, actual speed, and actual guide vane opening, a first flow rate value of the refrigerant flowing through the compressor is obtained; and a second flow rate value of the refrigerant flowing through the throttling device is obtained. Since the first flow rate value can be understood as the refrigerant flow rate required by the system under constant cooling demand, and the second flow rate value can be understood as the refrigerant flow rate corresponding to the actual circulation operation of the system, and when the system is in equilibrium, the refrigerant flow rate through the compressor and the refrigerant flow rate through the throttling device are approximately equal, therefore, the presence or absence of refrigerant leakage can be determined using the first and second flow rate values, thereby achieving accurate detection of refrigerant leakage.

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] Figure 1 This is a schematic diagram of a scenario provided for an embodiment of this application. For example... Figure 1 As shown, this scenario may include: a chiller (or chiller unit) 101, an electronic device 102, and a server 103, etc. The example of an electronic device 102 being a mobile phone is provided for illustration; this example does not constitute a limitation on the embodiments of this application. The chiller may be a centrifugal chiller.

[0038] In one implementation, the refrigerant leak detection method described in the embodiments of this application can be implemented in a chiller 101. The chiller 101 may include at least a compressor, a throttling device, and a processor, and the processor can be used to execute the refrigerant leak detection method described in the embodiments of this application.

[0039] In another implementation, the refrigerant leak detection method described in this application embodiment can be implemented in the electronic device 102. For example, when the chiller 101 is connected to the electronic device 102, the chiller 101 can send data such as the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual speed of the compressor, and the actual guide vane opening of the compressor to the electronic device 102, so that the electronic device 102 can perform refrigerant leak detection based on the data obtained from the chiller 101.

[0040] In another implementation, the refrigerant leak detection method described in this application embodiment can be implemented in server 103. For example, when chiller 101 is connected to server 103, chiller 101 can send data such as the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual speed of the compressor, and the actual guide vane opening of the compressor to server 103, so that server 103 can perform refrigerant leak detection based on the data obtained from chiller 101. Furthermore, server 103 can also send the detection results to electronic device 102, so that maintenance personnel can perform maintenance on chiller 101 based on the detection results displayed on electronic device 102.

[0041] It is understood that the subject performing the refrigerant leak detection method is not specifically limited in the embodiments of this application.

[0042] Figure 2 This is a schematic flowchart illustrating a refrigerant leak detection method provided in an embodiment of this application. Figure 2 In the corresponding embodiments, a chiller is used as an example to illustrate the refrigerant leak detection method. This example does not constitute a limitation on the embodiments of this application. Figure 2 As shown, a refrigerant leak detection method may include the following steps:

[0043] S201. Obtain the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual speed of the compressor, and the actual guide vane opening of the compressor.

[0044] The high-pressure side pressure may include the compressor's condensing pressure or the compressor's discharge pressure, etc.; the low-pressure side pressure may include the compressor's evaporating pressure or the compressor's suction pressure, etc.; the condensing pressure, discharge pressure, evaporating pressure, and suction pressure can all be obtained based on pressure sensor detection; the rotational speed can be calculated based on the motor's current and torque; the guide vane opening can be obtained based on a sensor connected to the guide vane. The condensing pressure can also be obtained by calculating the compressor's condensing outlet temperature and the compressor's condensing subcooling; the condensing outlet temperature can be obtained based on the condenser outlet temperature detected by a temperature sensor.

[0045] It is understood that the execution entity corresponding to the step shown in S201 can be: a processor in the chiller, an electronic device connected to the chiller, or a server connected to the chiller, etc., and this embodiment of the application does not limit this. Among them, when the execution entity corresponding to the step shown in S201 is an electronic device (or server), before S201, the process further includes: after the processor in the chiller obtains the high-pressure side pressure, the low-pressure side pressure, the actual speed of the compressor, and the actual guide vane opening of the compressor, it sends the high-pressure side pressure, the low-pressure side pressure, the actual speed, and the actual guide vane opening to the electronic device (or server).

[0046] S202. Based on the constraint relationship between the high-pressure side pressure, the low-pressure side pressure, the actual rotational speed, and the actual guide vane opening, the first flow rate of refrigerant through the compressor is obtained.

[0047] For example, the pressure ratio is calculated from the high-pressure side pressure and the low-pressure side pressure. The pressure ratio can be used to obtain the target speed and the target guide vane opening of the compressor. Further, based on the constraint relationship between the target speed and the actual speed, and the constraint relationship between the target guide vane opening and the actual guide vane opening, the first flow rate value is obtained.

[0048] S203. Obtain the second flow rate value of the refrigerant flowing through the throttling device.

[0049] The throttling device can be referred to as a throttling valve, an expansion valve (such as an electronic expansion valve), or a combination of an expansion valve and a throttling orifice plate, etc. The specific form of the throttling device is not limited in the embodiments of this application. The second flow rate value can be related to the high pressure side pressure, the low pressure side pressure, the second density of the refrigerant when it flows through the throttling device, the flow area of ​​the throttling device, and the flow coefficient of the throttling device.

[0050] It is understandable that since the second flow rate value can be understood as the refrigerant flow rate corresponding to the actual circulation operation of the chiller, and the failure of the throttling device will have a significant impact on the second flow rate value, in order to ensure the accuracy of the second flow rate value, the second flow rate value of the refrigerant flowing through the throttling device can be obtained when it is confirmed that the throttling device has not failed.

[0051] The throttling device is located between the condenser and the evaporator. Furthermore, when there are multiple throttling devices, they are connected in parallel between the condenser and the evaporator.

[0052] S204. Determine whether there is a refrigerant leak based on the first flow rate value and the second flow rate value.

[0053] Understandably, since the first flow rate of refrigerant flowing through the compressor is equal to the second flow rate of refrigerant flowing through the throttling device when the chiller is running normally, it can be determined that there is no refrigerant leak when the first flow rate is equal to the second flow rate, and that there is a refrigerant leak when the first flow rate is significantly different from the second flow rate.

[0054] It is understood that the execution entity corresponding to the steps shown in S202-S204 can be: a processor in the chiller, an electronic device connected to the chiller, or a server connected to the chiller, etc., and this application embodiment does not limit this.

[0055] Based on this, the flow rate of refrigerant through the compressor and the flow rate of refrigerant through the throttling device can be used to accurately determine whether there is a refrigerant leak. Furthermore, using conventionally measured values ​​for refrigerant leak detection can increase the ease of implementation.

[0056] exist Figure 2 Based on the corresponding embodiment, S204 includes: determining that refrigerant is leaking when the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold; or determining that there is no refrigerant leak when the difference between the first flow rate value and the second flow rate value is less than the first threshold.

[0057] The value of the first threshold can be a specific numerical value or a range of numerical values, which is not limited in this embodiment; the difference between the first flow value and the second flow value can be: the difference between the first flow value and the second flow value (or the absolute value of the difference), or the difference between the second flow value and the first flow value (or the absolute value of the difference).

[0058] Understandably, different chillers correspond to different unit capacities, and the difference in capacity will affect the value of the first threshold. Therefore, the value under normal circumstances in a chiller leakage scenario can be determined by dividing the difference between the first flow rate value and the second flow rate value by the total capacity of the unit, and by dividing the first threshold by the total capacity of the unit, to obtain the percentage difference.

[0059] For example, when the first threshold is a specific value, the threshold percentage corresponding to the first threshold can be 1% or 5% or other values; or, when the first threshold is a range of values, the threshold percentage corresponding to the range of the first threshold can be 1%-10%. In this embodiment, no specific value is limited.

[0060] Furthermore, multiple ranges of values ​​can be set for the first threshold (or the threshold percentage corresponding to the first threshold), and these ranges can correspond to different refrigerant leakage levels. It is understandable that since the first flow rate value represents the refrigerant flow rate required by the chiller under constant cooling demand, and the second flow rate value represents the refrigerant flow rate corresponding to the actual circulating operation of the chiller, the difference between the first and second flow rate values ​​can represent the severity of the refrigerant leak. Therefore, by setting different refrigerant leakage levels, the chiller can perform corresponding maintenance procedures under different refrigerant leakage levels.

[0061] For example, three threshold percentage ranges can be set for the first threshold, such as: a range for a minor refrigerant leak level, such as a threshold percentage range of 1%-3% (e.g., 1%, 2%, and 3%); a range for a moderate refrigerant leak level, such as a threshold percentage range of 3%-6% (e.g., 4%, 5%, and 6%); and a range for a severe refrigerant leak level, such as a threshold percentage range of 6%-10% (e.g., 7%, 9%, and 10%).

[0062] For example, if the detected difference percentage is between 1% and 3%, the chiller determines that the current refrigerant leak level is minor, and the chiller can continue to operate normally and send a prompt message to the electronic equipment; if the detected difference percentage is between 3% and 6%, the chiller determines that the current refrigerant leak level is moderate, and the chiller can execute a frequency reduction procedure and send a prompt message to the electronic equipment; or, if the detected difference percentage is between 6% and 10%, the chiller determines that the current refrigerant leak level is severe, and the chiller can execute an automatic shutdown procedure, initiate an alarm, and send a prompt message to the electronic equipment.

[0063] It is understood that the number of refrigerant leakage levels, the range of threshold percentages under each refrigerant leakage level, and the maintenance procedures for chillers under different refrigerant leakage levels are merely examples and are not limited in this embodiment.

[0064] Based on this, the difference between the refrigerant flow rate through the compressor and the refrigerant flow rate through the throttling device can be used to accurately determine whether there is a refrigerant leak; and maintenance procedures can be implemented under different refrigerant leak levels to ensure the normal operation of the chiller.

[0065] exist Figure 2 Based on the corresponding embodiment, when the time when the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold exceeds the second threshold, a refrigerant leak is determined.

[0066] The value of the second threshold can be a specific numerical value or a range of time values; this application embodiment does not limit this.

[0067] For example, if the second threshold is set to 1 minute, a refrigerant leak is determined when the difference between the first flow rate and the second flow rate is greater than or equal to the first threshold for more than one minute. Alternatively, the chiller can also calculate the average difference between the first flow rate and the second flow rate over a period of time, and determine a refrigerant leak when the average difference over a period of time is greater than a certain threshold.

[0068] It is understood that the specific implementation of determining refrigerant leakage using the difference between the first flow rate value and the second flow rate value is not limited in the embodiments of this application.

[0069] Furthermore, multiple value ranges can be set for times when the difference is greater than or equal to the first threshold. These multiple value ranges can correspond to different refrigerant leakage levels. The relevant descriptions of refrigerant leakage levels will not be repeated here.

[0070] Based on this, the time it takes for the difference between the refrigerant flow rate through the compressor and the refrigerant flow rate through the throttling device to exceed a first threshold can be used to accurately determine whether a refrigerant leak has occurred, and this can increase the robustness of refrigerant leak detection.

[0071] exist Figure 2 Based on the corresponding embodiment, S202 includes: obtaining the target speed and the target guide vane opening based on the third flow value preset by the compressor and the ratio of the high-pressure side pressure to the low-pressure side pressure; when the difference between the target speed and the actual speed is less than or equal to the third threshold, and the difference between the target guide vane opening and the actual guide vane opening is less than or equal to the fourth threshold, the third flow value is determined as the first flow value.

[0072] Alternatively, when the difference between the target speed and the actual speed is greater than the third threshold, and / or the difference between the target guide vane opening and the actual guide vane opening is greater than the fourth threshold, the third flow rate value is adjusted to obtain the adjusted third flow rate value; based on the adjusted third flow rate value and the ratio of the high-pressure side pressure to the low-pressure side pressure, the target speed and the target guide vane opening are obtained.

[0073] There is a corresponding relationship between the third flow rate value, the ratio, and the target rotational speed; there is also a corresponding relationship between the third flow rate value, the ratio, and the target guide vane opening.

[0074] For example, one possible implementation for determining the first flow rate value based on the compressor's preset third flow rate value, high-pressure side pressure, low-pressure side pressure, actual speed, and actual guide vane opening can be found below. Figure 3 Corresponding implementation examples. Figure 3 This is a schematic diagram of a process for obtaining a first flow rate value, provided as an embodiment of this application.

[0075] like Figure 3 As shown, the method for obtaining the first flow rate value may include:

[0076] S301. The pressure ratio is obtained based on the high-pressure side pressure and the low-pressure side pressure.

[0077] The pressure ratio can be the ratio of the high-pressure side pressure to the low-pressure side pressure, such as the ratio obtained by dividing the high-pressure side pressure by the low-pressure side pressure.

[0078] S302. The target rotational speed is obtained based on the correspondence between pressure ratio, flow rate, and rotational speed. The target guide vane opening is obtained based on the correspondence between pressure ratio, flow rate, and guide vane opening.

[0079] It is understandable that a chiller can store multiple sets of relationships between pressure ratio, flow rate, and rotational speed, as well as multiple sets of relationships between pressure ratio, flow rate, and guide vane opening. This allows the chiller to determine the corresponding target rotational speed and the corresponding target guide vane opening based on a third flow rate and pressure ratio. This third flow rate can be preset. For example, it could be the flow rate of refrigerant through the compressor during normal operation of the chiller.

[0080] S303. Calculate the difference between the target speed and the actual speed, and the difference between the target guide vane opening and the actual guide vane opening.

[0081] The difference between the target speed and the actual speed can be: the difference between the target speed and the actual speed (or the absolute value of the difference), or the difference between the actual speed and the target speed (or the absolute value of the difference); the difference between the target guide vane opening and the actual guide vane opening can be: the difference between the target guide vane opening and the actual guide vane opening (or the absolute value of the difference), or the difference between the actual guide vane opening and the target guide vane opening (or the absolute value of the difference).

[0082] S304. Determine whether the difference between the target speed and the actual speed is less than or equal to the third threshold, and whether the difference between the target guide vane opening and the actual guide vane opening is less than or equal to the fourth threshold.

[0083] Specifically, when the difference between the target speed and the actual speed is less than or equal to the third threshold, and the difference between the target guide vane opening and the actual guide vane opening is less than or equal to the fourth threshold, the chiller can execute the steps shown in S305.

[0084] Alternatively, when the difference between the target speed and the actual speed is determined to be greater than the third threshold, and / or the difference between the target guide vane opening and the actual guide vane opening is greater than the fourth threshold, the chiller may execute the steps shown in S306.

[0085] S305, The third flow rate value is determined as the first flow rate value.

[0086] It is understandable that, since the theoretical target speed corresponding to the third flow rate value satisfies the constraint relationship between the actual measured speed and the theoretical target guide vane opening corresponding to the third flow rate value satisfies the constraint relationship between the actual measured guide vane opening and the theoretical target guide vane opening corresponding to the third flow rate value, the third flow rate value can be determined as the first flow rate value of the refrigerant flowing through the compressor.

[0087] S306. Adjust the third flow rate value to obtain the adjusted third flow rate value.

[0088] The adjusted third flow rate value can be used to replace the third flow rate value in step S302, and the steps S301-S306 can be continued until the first flow rate value that meets the requirements is output.

[0089] It is understandable that when the theoretical target speed corresponding to the third flow rate value does not satisfy the constraint relationship with the actual measured speed, and / or when the theoretical target guide vane opening corresponding to the third flow rate value does not satisfy the constraint relationship with the actual measured guide vane opening, a deviation will occur between the third flow rate value and the current flow rate of refrigerant flowing through the compressor. Therefore, the third flow rate value can be adjusted to make it closer to the current flow rate of refrigerant flowing through the compressor.

[0090] For example, when the difference between the target rotational speed and the actual rotational speed is greater than or equal to a certain threshold (and / or the difference between the target guide vane opening and the actual guide vane opening is greater than or equal to a certain threshold), it indicates that the value of the third flow rate is large, so the third flow rate can be reduced based on the target step size; or, when the difference between the target rotational speed and the actual rotational speed is less than a certain threshold (and / or the difference between the target guide vane opening and the actual guide vane opening is less than a certain threshold), it indicates that the value of the third flow rate is small, so the third flow rate can be increased based on the target step size, thereby obtaining the third flow rate corresponding to when the target rotational speed and the actual rotational speed (and / or the target guide vane opening and the actual guide vane opening) are almost equal.

[0091] In a possible implementation, when the third flow rate value is a volumetric flow rate, determining the third flow rate value as the first flow rate value includes: obtaining the mass flow rate corresponding to the third flow rate value based on the third flow rate value and the first density of the refrigerant when it flows through the compressor; and determining the mass flow rate as the first flow rate value.

[0092] The first density is obtained based on the low-pressure side pressure and the compressor's suction temperature, which can also be replaced by superheat.

[0093] For example, a chiller can store the correspondence between density, low-pressure side pressure, and suction temperature. When the third flow rate value is a volumetric flow rate, the chiller can obtain the corresponding first density of the refrigerant based on the measured low-pressure side pressure and suction temperature, and multiply the third flow rate value by the first density of the refrigerant to obtain the mass flow rate corresponding to the third flow rate value. This mass flow rate corresponding to the third flow rate value is then used as the first flow rate value. The correspondence between density, low-pressure side pressure, and suction temperature can also be collectively referred to as refrigerant properties.

[0094] It is understandable that, such as Figure 3 As shown, when the third flow rate value in step S302 is volumetric flow rate, the third flow rate value in step S305 can be the mass flow rate obtained after processing. The third flow rate value in step S306 and the adjusted third flow rate value can both be volumetric flow rate.

[0095] Based on this, the first flow rate of refrigerant through the compressor can be accurately output based on the constraints between the high-pressure side pressure, the low-pressure side pressure, the actual rotational speed, and the actual guide vane opening.

[0096] exist Figure 2 Based on the corresponding embodiment, S203 includes: obtaining a second flow rate value based on the high-pressure side pressure, the low-pressure side pressure, the second density of the refrigerant when it flows through the throttling device, the flow area of ​​the throttling device, and the flow coefficient of the throttling device.

[0097] The second density is obtained based on the high-pressure side pressure and the inlet temperature of the throttling device; the inlet temperature of the throttling device can also be replaced by the condenser outlet temperature.

[0098] It is understandable that a chiller can store the relationship between high-pressure side pressure, inlet temperature of the throttling device, and density, allowing the chiller to obtain a second density based on the actually measured high-pressure side pressure and inlet temperature of the throttling device. This relationship between high-pressure side pressure, inlet temperature of the throttling device, and density can also be referred to as refrigerant properties.

[0099] For example, the calculation method for the second flow rate value m can be found in the following formula (1):

[0100]

[0101] Among them, C D ρ can be the flow coefficient; A can be the flow area of ​​the throttling device; ρ can be the second density; P1 can be the high-pressure side pressure; P2 can be the low-pressure side pressure.

[0102] In possible implementations, the flow coefficient can be obtained directly, or indirectly from the opening degree of the throttling device or the number of motor steps of the throttling device. For example, the chiller can store the correspondence between the flow coefficient and the opening degree of the throttling device. When the actual opening degree is obtained through measurement, the chiller can obtain the flow coefficient corresponding to the actual opening degree based on the correspondence between the flow coefficient and the opening degree of the throttling device. Alternatively, the chiller can also store the correspondence between the flow coefficient and the number of motor steps of the throttling device. When the actual number of motor steps is obtained through measurement, the chiller can obtain the flow coefficient corresponding to the actual number of motor steps based on the correspondence between the flow coefficient and the number of motor steps of the throttling device.

[0103] It is understood that the method for obtaining the flow coefficient in this application embodiment is not specifically limited.

[0104] Based on this, the chiller can obtain a relatively accurate second flow rate value according to the high-pressure side pressure, the low-pressure side pressure, the second density of the refrigerant when it flows through the throttling device, the flow area of ​​the throttling device, and the flow coefficient of the throttling device.

[0105] exist Figure 2 Based on the corresponding embodiment, when there are multiple compressors and multiple throttling devices, S201 includes: determining whether refrigerant is leaking based on the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values.

[0106] In one implementation, a refrigerant leak is determined when the difference between the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values ​​is greater than or equal to a fifth threshold; or, no refrigerant leak is determined when the difference between the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values ​​is less than the fifth threshold.

[0107] For example, when the chiller includes a first compressor, a second compressor, a first throttling device, and a second throttling device, the chiller can calculate the sum of the flow rates of the refrigerant flowing through the first compressor and the refrigerant flowing through the second compressor to obtain the total flow rate of the compressors; the chiller can also calculate the sum of the flow rates of the refrigerant flowing through the first throttling device and the refrigerant flowing through the second throttling device to obtain the total flow rate of the throttling devices. Furthermore, when the difference between the total flow rate of the compressors and the total flow rate of the throttling devices is greater than or equal to a fifth threshold, a refrigerant leak is determined.

[0108] Furthermore, when the time when the difference between the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values ​​is greater than or equal to the fifth threshold exceeds a certain threshold, a refrigerant leak is determined.

[0109] In another implementation, the flow rate of refrigerant passing through each compressor is obtained, and the average flow rate of each compressor is calculated. The flow rate of refrigerant passing through each throttling device is obtained, and the average flow rate of each throttling device is calculated. When the difference between the average flow rate of each compressor and the average flow rate of each throttling device is greater than or equal to a sixth threshold, refrigerant leakage is determined. Alternatively, when the difference between the average flow rate of each compressor and the average flow rate of each throttling device is less than the sixth threshold, no refrigerant leakage is determined.

[0110] For example, when the chiller includes a first compressor, a second compressor, a first throttling device, and a second throttling device, the chiller can calculate the average flow rate of the refrigerant when it flows through the first compressor and the average flow rate of the refrigerant when it flows through the second compressor, thus obtaining the average flow rate of the compressor. The chiller can also calculate the average flow rate of the refrigerant when it flows through the first throttling device and the average flow rate of the refrigerant when it flows through the second throttling device, thus obtaining the average flow rate of the throttling device. Furthermore, when the difference between the average flow rate of the compressor and the average flow rate of the throttling device is greater than or equal to a sixth threshold, a refrigerant leak is determined.

[0111] Furthermore, when the time when the difference between the average flow rate value corresponding to each compressor and the average flow rate value corresponding to each throttling device is greater than or equal to the sixth threshold exceeds a certain threshold, a refrigerant leak is determined.

[0112] Therefore, even if a chiller includes multiple compressors and multiple throttling devices, the chiller can detect refrigerant leakage based on the difference between the sum (or average) of the first flow rate values ​​calculated by each compressor and the sum (or average) of the second flow rate values ​​calculated by each throttling device.

[0113] exist Figure 2 Based on the corresponding embodiments, the method further includes: when a refrigerant leak is determined, sending indication information to an electronic device to indicate the refrigerant leak, so that the electronic device can provide a refrigerant leak warning based on the indication information.

[0114] For example, when a communication connection is established between the chiller and the electronic device, the chiller can send a notification message to the electronic device upon detecting a refrigerant leak. This allows the electronic device to initiate a user notification, which can instruct the user to handle the refrigerant leak promptly. For instance, the user notification could be a notification interface on the electronic device, or it could be an alarm sound initiated by the electronic device; this embodiment does not limit the specific form of the notification.

[0115] The electronic device may include a device containing an electronic control board or a chip, etc. The embodiments of this application do not limit the specific technology or specific device form used in the electronic device.

[0116] Based on this, electronic devices can promptly alert users to refrigerant leaks based on the prompts sent by the chiller, allowing users to detect refrigerant leaks in time and avoid affecting the chiller's working efficiency.

[0117] exist Figure 2 Based on the corresponding embodiments, it also includes: executing a preset maintenance procedure when a refrigerant leak is determined.

[0118] For example, a maintenance procedure for refrigerant leaks can be set up in the chiller, so that the chiller automatically triggers the maintenance procedure when a refrigerant leak is detected, thereby automating the detection and maintenance of refrigerant leaks. This maintenance procedure may include: a frequency reduction procedure and an automatic shutdown procedure, etc.

[0119] Based on the content described in the above embodiments, in order to better understand the various embodiments of this application, the following describes in detail an implementation process of refrigerant leakage detection provided in the embodiments of this application, taking the high-pressure side pressure as the condensing pressure, the low-pressure side pressure as the evaporating pressure, and the throttling device as the expansion valve. For example, Figure 4 This is a schematic flowchart of another refrigerant leak detection method provided in an embodiment of this application.

[0120] like Figure 4As shown, the refrigerant leak detection method may include the following steps:

[0121] S401. Data acquisition is performed while the chiller is running.

[0122] This data may include: the actual speed of the compressor, the actual guide vane opening of the compressor, the suction temperature of the compressor, the evaporation pressure of the compressor, the condensing pressure of the compressor, the condensing outlet temperature of the compressor, and the opening of the expansion valve (or the number of motor steps of the expansion valve), etc.

[0123] In a possible implementation, to avoid the influence of measurement noise on the measurement results, the chiller can perform noise reduction processing on the data acquired in step S401, and use the noise-reduced data as the data input in steps S402 and S403. This noise reduction processing may include methods such as Kalman filtering; however, this embodiment does not specifically limit the noise reduction processing method.

[0124] S402. By utilizing the relationship between flow rate, pressure ratio, and rotational speed, the relationship between flow rate, pressure ratio, and guide vane opening, the actual rotational speed, actual guide vane opening, suction temperature, evaporation pressure, condensation pressure, and refrigerant properties, the theoretical flow rate of the compressor is obtained.

[0125] The refrigerant properties may include the relationship between density, evaporation pressure and suction temperature; the compressor theoretical flow rate may be the first flow rate value described in the embodiments of this application.

[0126] Understandably, the method for obtaining the theoretical flow rate of the compressor can be found in [reference needed]. Figure 3 The method for obtaining the first flow rate value in the corresponding embodiment will not be described in detail here.

[0127] S403. Using the evaporation pressure, condensation pressure, condensation outlet temperature, expansion valve opening (or expansion valve motor steps), and refrigerant properties, the theoretical flow rate of the expansion valve is obtained.

[0128] The refrigerant properties may also include the relationship between high-pressure side pressure, condenser outlet temperature and density; the compressor theoretical flow rate may be the second flow rate value described in the embodiments of this application.

[0129] It is understandable that the method for obtaining the theoretical flow rate of the expansion valve can be found in the method for obtaining the second flow rate value in formula (1), and will not be repeated here.

[0130] S404, Calculate the flow deviation.

[0131] This flow deviation can be the difference between the theoretical flow rate of the compressor and the theoretical flow rate of the expansion valve.

[0132] In a possible implementation, when there are multiple compressors and multiple expansion valves, the flow deviation can be the difference between the sum of the theoretical flow rates of each compressor and the sum of the theoretical flow rates of each expansion valve.

[0133] S405. Determine if the absolute value of the flow deviation is greater than or equal to θ, and if the time during which the absolute value of the flow deviation is greater than or equal to θ is greater than a set time.

[0134] Specifically, when the absolute value of the flow deviation is greater than or equal to θ, and the time for which the absolute value of the flow deviation is greater than or equal to θ is greater than a set time, steps S406-S407 are executed. When the absolute value of the flow deviation is less than θ, and / or the time for which the absolute value of the flow deviation is greater than or equal to θ is less than or equal to a set time, the chiller operates normally and continues to execute the refrigerant leak detection process.

[0135] In possible implementations, when there are multiple compressors and multiple expansion valves, the value of θ can be different. For example, the value of θ can be related to the number of compressors (or the number of expansion valves). For instance, when the number of compressors and expansion valves is 1, the threshold for judging flow deviation can be θ; when the number of compressors and expansion valves is 2, the threshold for judging flow deviation can be 2θ.

[0136] S406. Determine the refrigerant leak level.

[0137] S407. Determine the maintenance response.

[0138] For example, a chiller can perform the maintenance procedures corresponding to the refrigerant leak level.

[0139] Based on this, the chiller can accurately detect refrigerant leaks based on the theoretical flow rate of the compressor and the theoretical flow rate of the expansion valve. Furthermore, the use of conventionally measured values ​​for refrigerant leak detection increases the ease of implementation.

[0140] Based on the above embodiments, Figure 5 This is a structural schematic diagram of a chiller 500 provided in an embodiment of this application. Figure 5 As shown, the chiller 500 includes: a processor 501 and a memory 502.

[0141] The memory 502 stores a computer program; the processor 501 executes the computer program stored in the memory to implement the refrigerant leak detection method in the above method embodiments.

[0142] In this embodiment, the memory 502 and the processor 501 are electrically connected directly or indirectly to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines, such as bus 503. The memory 502 stores computer execution instructions that implement data access control methods, including at least one software functional module that can be stored in the memory in the form of software or firmware. The processor 501 executes various functional applications and data processing by running the software programs and modules stored in the memory.

[0143] The memory 502 may be, but is not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), etc. The memory stores programs, which are executed by the processor upon receiving execution instructions. Furthermore, the software programs and modules within the memory may include an operating system, which may include various software components and / or drivers for managing system tasks (e.g., memory management, storage device control, power management, etc.) and can communicate with various hardware or software components to provide an operating environment for other software components.

[0144] Processor 501 can be an integrated circuit chip with signal processing capabilities. The aforementioned processor 501 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor.

[0145] It should be noted that the chiller provided in this embodiment can be used to perform the above-mentioned refrigerant leak detection method, and its implementation method and technical effect are similar, so it will not be described again in this embodiment.

[0146] The steps of the method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0147] This application also provides a refrigerant leak detection device. For example, Figure 6 This is a schematic diagram of the structure of a refrigerant leak detection device 600 provided in an embodiment of this application, as shown below. Figure 6 As shown, the refrigerant leak detection device 600 may include: an acquisition module 601 and a determination module 602.

[0148] Specifically, the acquisition module 601 is used to acquire the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual speed of the compressor, and the actual guide vane opening of the compressor; the determination module 602 is used to obtain the first flow rate value of the refrigerant flowing through the compressor based on the constraint relationship between the high-pressure side pressure, the low-pressure side pressure, the actual speed, and the actual guide vane opening; the acquisition module 601 is also used to acquire the second flow rate value of the refrigerant flowing through the throttling device; the throttling device is set between the condenser and the evaporator; the determination module 602 is also used to determine whether there is a refrigerant leak based on the first flow rate value and the second flow rate value.

[0149] In some embodiments, the determining module 602 is specifically used to: determine refrigerant leakage when the difference between the first flow rate value and the second flow rate value is greater than or equal to a first threshold; or determine that there is no refrigerant leakage when the difference between the first flow rate value and the second flow rate value is less than the first threshold.

[0150] In some embodiments, the determining module 602 is specifically used to: determine refrigerant leakage when the time when the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold exceeds the second threshold.

[0151] In some embodiments, the determining module 602 is specifically used to: obtain the target speed and the target guide vane opening based on the third flow value preset by the compressor and the ratio of the high-pressure side pressure to the low-pressure side pressure; wherein, there is a corresponding relationship between the third flow value, the ratio, and the target speed; there is a corresponding relationship between the third flow value, the ratio, and the target guide vane opening; when the difference between the target speed and the actual speed is less than or equal to a third threshold, and the difference between the target guide vane opening and the actual guide vane opening is less than or equal to a fourth threshold, the third flow value is determined as the first flow value.

[0152] In some embodiments, the determining module 602 is specifically used to: adjust the third flow rate value when the difference between the target rotational speed and the actual rotational speed is greater than a third threshold, and / or the difference between the target guide vane opening and the actual guide vane opening is greater than a fourth threshold, to obtain the adjusted third flow rate value; and obtain the target rotational speed and the target guide vane opening based on the adjusted third flow rate value and the ratio of the high-pressure side pressure to the low-pressure side pressure.

[0153] In some embodiments, the determining module 602 is specifically used to: obtain the mass flow rate corresponding to the third flow rate value based on the third flow rate value and the first density of the refrigerant when it flows through the compressor; wherein the first density is obtained based on the low-pressure side pressure and the suction temperature of the compressor; and determine the mass flow rate as the first flow rate value.

[0154] In some embodiments, the acquisition module 601 is specifically used to: acquire a second flow rate value of the refrigerant flowing through the throttling device, including: obtaining the second flow rate value based on the high-pressure side pressure, the low-pressure side pressure, the second density of the refrigerant flowing through the throttling device, the flow area of ​​the throttling device, and the flow coefficient of the throttling device; wherein the second density is obtained based on the high-pressure side pressure and the inlet temperature of the throttling device.

[0155] In some embodiments, there are multiple compressors and multiple throttling devices. The determining module 602 is specifically used to determine whether there is a refrigerant leak based on the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values.

[0156] In some embodiments, the determining module 602 is specifically configured to: determine whether a refrigerant is leaking based on the sum of a plurality of first flow rate values ​​and the sum of a plurality of second flow rate values, including: determining a refrigerant leak when the difference between the sum of the plurality of first flow rate values ​​and the sum of the plurality of second flow rate values ​​is greater than or equal to a fifth threshold; or, determining that the refrigerant is not leaking when the difference between the sum of the plurality of first flow rate values ​​and the sum of the plurality of second flow rate values ​​is less than the fifth threshold.

[0157] In some embodiments, the determining module 602 is specifically used to: execute a preset maintenance process when a refrigerant leak is determined; wherein the maintenance process includes: a frequency reduction process or an automatic shutdown process.

[0158] In some embodiments, the refrigerant leak detection device 600 further includes a communication module, which, when a refrigerant leak is determined, is configured to send indication information to an electronic device to indicate the refrigerant leak, so that the electronic device can provide a refrigerant leak alert based on the indication information.

[0159] In some embodiments, when there are multiple throttling devices, the multiple throttling devices are arranged in parallel between the condenser and the evaporator.

[0160] In some optional embodiments, the refrigerant leak detection device 600 may further include a storage module for storing data and / or instructions. The refrigerant leak detection device provided in this embodiment (such as the acquisition module 601 and determination module 602 mentioned above) can be used to read the data and instructions in the storage module to implement the above-mentioned refrigerant leak detection method. The implementation method and technical effects are similar, and will not be described again in this embodiment.

[0161] It should be noted that the acquisition module 601 in the above embodiments can actually be a receiver, used to receive information sent by other devices or measurement units, such as the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual speed of the compressor, and the actual guide vane opening of the compressor. The acquisition module 601 can be implemented through a communication port.

[0162] In some alternative implementations, the determination module 602 can be implemented in software via a processing element or in hardware. For example, the determination module 602 can be a separately established processing element or integrated into a chip in the refrigerant leak detection device. Alternatively, it can be stored as program code in the storage module of the refrigerant leak detection device 600, for use by a processing element of the refrigerant leak detection device 600 to call and execute some or all of the functions of the determination module 602.

[0163] Furthermore, all or part of these processing elements can be integrated together or implemented independently. The module here can be an integrated circuit with signal processing capabilities. During implementation, each step of the above method or each of the above modules can be completed through integrated logic circuits in the hardware of the processor element or through software instructions.

[0164] For example, these modules can be one or more integrated circuits configured to implement the refrigerant leak detection method described above. Examples include one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs). Furthermore, when a module is implemented using processing element scheduler code, the processing element can be a single processor, such as a central processing unit (CPU) or other processor capable of calling program code. These modules can also be integrated together as a system-on-a-chip.

[0165] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the methods of any of the above embodiments.

[0166] The methods described in the above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. Computer-readable media can include computer storage media and communication media, and can also include any medium capable of transferring a computer program from one place to another. Storage media can be any target medium accessible by a computer.

[0167] As one possible design, computer-readable media may include compact disc read-only memory (CD-ROM), RAM, ROM, EEPROM, or other optical disc storage; computer-readable media may include disk storage or other disk storage devices. Furthermore, any connecting cable may also be appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. As used herein, disks and optical discs include optical discs (CD), laser discs, optical discs, digital versatile discs (DVD), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs optically reproduce data using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0168] Based on the above embodiments, Figure 7 This is a schematic diagram of the structure of a refrigerant leak detection system 700 provided in an embodiment of this application. Figure 7 In the corresponding embodiment, a tablet computer is used as an example for illustration.

[0169] like Figure 7 As shown, the refrigerant leak detection system 700 may include a chiller 701 and an electronic device 702. When the chiller 701 and the electronic device 702 are connected, after the processor in the chiller 701 acquires the high-pressure side pressure, low-pressure side pressure, actual speed, and actual guide vane opening of the compressor, it sends these values ​​to the electronic device 702. The electronic device 702 acquires these values ​​from the chiller 701 and, based on the relationship between them, obtains a first flow rate value of the refrigerant flowing through the compressor. The electronic device 702 also acquires a second flow rate value of the refrigerant flowing through the throttling device. The electronic device 702 determines whether there is a refrigerant leak based on the first and second flow rate values.

[0170] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0171] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0172] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0173] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0174] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0175] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for detecting refrigerant leaks, characterized in that, The method includes: The compressor's high-pressure side pressure, low-pressure side pressure, actual speed, and actual guide vane opening are obtained. Based on the constraint relationship between the high-pressure side pressure, the low-pressure side pressure, the actual rotational speed, and the actual guide vane opening, the first flow rate value of the refrigerant flowing through the compressor is obtained; Obtain the second flow rate value of the refrigerant flowing through the throttling device; the throttling device is disposed between the condenser and the evaporator; Determine whether the refrigerant is leaking based on the first flow rate value and the second flow rate value; The step of obtaining the first flow rate value of the refrigerant flowing through the compressor based on the constraint relationship between the high-pressure side pressure, the low-pressure side pressure, the actual rotational speed, and the actual guide vane opening includes: Based on the preset third flow rate value of the compressor and the ratio of the high-pressure side pressure to the low-pressure side pressure, the target speed and the target guide vane opening are obtained; wherein, there is a corresponding relationship between the third flow rate value, the ratio, and the target speed; there is a corresponding relationship between the third flow rate value, the ratio, and the target guide vane opening. When the difference between the target rotational speed and the actual rotational speed is less than or equal to a third threshold, and the difference between the target guide vane opening and the actual guide vane opening is less than or equal to a fourth threshold, the third flow rate value is determined to be the first flow rate value.

2. The method according to claim 1, characterized in that, The step of determining whether the refrigerant is leaking based on the first flow rate value and the second flow rate value includes: When the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold, it is determined that the refrigerant is leaking. Alternatively, if the difference between the first flow rate value and the second flow rate value is less than the first threshold, it is determined that the refrigerant is not leaking.

3. The method according to claim 2, characterized in that, Determining a refrigerant leak when the difference between the first flow rate value and the second flow rate value is greater than or equal to a first threshold includes: When the time for which the difference between the first flow rate value and the second flow rate value is greater than or equal to the first threshold exceeds the second threshold, it is determined that the refrigerant is leaking.

4. The method according to claim 1, characterized in that, The method further includes: When the difference between the target rotational speed and the actual rotational speed is greater than the third threshold, and / or the difference between the target guide vane opening and the actual guide vane opening is greater than the fourth threshold, the third flow rate value is adjusted to obtain the adjusted third flow rate value. The step of obtaining the target speed and target guide vane opening based on the preset third flow rate value of the compressor and the ratio of the high-pressure side pressure to the low-pressure side pressure includes: obtaining the target speed and target guide vane opening based on the adjusted third flow rate value and the ratio of the high-pressure side pressure to the low-pressure side pressure.

5. The method according to claim 1, characterized in that, The third flow rate value is a volumetric flow rate, and determining that the third flow rate value is the first flow rate value includes: The mass flow rate corresponding to the third flow rate is obtained based on the third flow rate value and the first density of the refrigerant when it flows through the compressor; wherein, the first density is obtained based on the low-pressure side pressure and the suction temperature of the compressor; The mass flow rate is determined to be the first flow rate value.

6. The method according to claim 5, characterized in that, The step of obtaining the second flow rate value of the refrigerant flowing through the throttling device includes: The second flow rate value is obtained based on the high-pressure side pressure, the low-pressure side pressure, the second density of the refrigerant when it flows through the throttling device, the flow area of ​​the throttling device, and the flow coefficient of the throttling device; wherein the second density is obtained based on the high-pressure side pressure and the inlet temperature of the throttling device.

7. The method according to claim 1, characterized in that, The number of compressors is multiple, the number of throttling devices is multiple, and the step of determining whether the refrigerant is leaking based on the first flow rate value and the second flow rate value includes: Whether the refrigerant is leaking is determined based on the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values.

8. The method according to claim 7, characterized in that, The step of determining whether the refrigerant is leaking based on the sum of multiple first flow rate values ​​and the sum of multiple second flow rate values ​​includes: When the difference between the sum of the plurality of first flow rate values ​​and the sum of the plurality of second flow rate values ​​is greater than or equal to a fifth threshold, the refrigerant leak is determined. Alternatively, if the difference between the sum of the plurality of first flow rate values ​​and the sum of the plurality of second flow rate values ​​is less than the fifth threshold, it is determined that the refrigerant is not leaking.

9. The method according to claim 1, characterized in that, The method further includes: When a refrigerant leak is confirmed, a preset maintenance procedure is executed; wherein the maintenance procedure includes: a frequency reduction procedure or an automatic shutdown procedure.

10. The method according to claim 1, characterized in that, The method further includes: Upon determining that the refrigerant leak is detected, an indication message for indicating the refrigerant leak is sent to the electronic device, which then provides a refrigerant leak alert based on the indication message.

11. The method according to claim 1, characterized in that, When there are multiple throttling devices, the multiple throttling devices are connected in parallel between the condenser and the evaporator.

12. A chiller, characterized in that, The chiller is used to perform the method as described in any one of claims 1-11.

13. An electronic device, characterized in that, The electronic device includes a processor for performing the method as described in any one of claims 1-11.

14. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the method as described in any one of claims 1-11.

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