Automatic control method, device and system for simulating refrigerant leakage

Abstract

The application discloses an automatic control method, device and system for simulating refrigerant leakage, and the method comprises the following steps: if the refrigerant type, the set leakage rate and the leakage time input by a user are received, the refrigerant gas density is selected according to the refrigerant type; the set volume flow is obtained according to the set leakage rate and the refrigerant gas density; one injection circuit is selected between a first injection circuit and a second injection circuit according to the set volume flow, and refrigerant injection is carried out; after the time of the current injection reaches the leakage time, the refrigerant change amount provided by a weighing device is received, and the actual leakage rate of the current injection is obtained according to the refrigerant change amount and the leakage time. The automatic control for simulating refrigerant leakage can be realized, and the first injection circuit and the second injection circuit with different effective ranges of flow regulation are set, so that the wide-range control of flow is realized, the control error is reduced as much as possible, and the control precision is kept within the standard requirement range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of simulation test, in particular to an automatic control method, device and system for simulating refrigerant leakage. BACKGROUND

[0002] With the improvement of environmental protection requirements, the standards of refrigerant in ozone depletion potential (ODP) and greenhouse effect potential (GWP) are becoming increasingly stringent, while the economy and refrigeration efficiency of air conditioning systems also need to be considered. In recent years, flammable refrigerants such as R32, R454B and R290 have gradually increased in the application of air conditioning and heat pump fields.

[0003] The installation capacity of such new flammable refrigerants increases. Due to their flammability, if leakage occurs during production, use and maintenance, it may cause combustion or explosion when encountering open flame or electric spark. In recent years, safety accidents caused by refrigerant leakage have increased both at home and abroad.

[0004] In order to cope with the potential safety risks during the use of flammable refrigerants, some regions have introduced relevant technical standards (such as IEC 60335-2-40:2022, UL / CSA 60335-2-40:2022) to regulate the use of flammable refrigerants and the detection and control of leakage.

[0005] In order to monitor the leakage of refrigerant, the concentration of refrigerant in the environment needs to be detected in real time by using refrigerant gas sensors to determine whether it is within a safe range. When the sensor detects a certain concentration of refrigerant gas, the system can determine that there is a leakage, and then slow down the leakage by closing the compressor and control valve, while starting the exhaust system to quickly dilute the leaked refrigerant to prevent it from accumulating to the combustion or explosion limit, thereby avoiding safety accidents.

[0006] Among them, the response time of the refrigerant gas sensor to the refrigerant gas is the key to whether the whole system can make a quick and effective judgment. In addition to being determined by the principle and characteristics of the sensor itself, the installation position of the refrigerant gas sensor in the air conditioning system is also crucial.

[0007] Due to the large number of internal components in the air conditioning system and the complexity, when selecting the installation position of the refrigerant gas sensor, in addition to considering the convenience of installation and maintenance, it also needs to consider whether it can quickly respond to the leakage of refrigerant under various wind speed conditions to meet the requirements of relevant standards. Among them, it is necessary to simulate the leakage of each point where refrigerant leakage is easy to occur to test whether the installation position of the refrigerant gas sensor can detect the refrigerant concentration that triggers the alarm within the standard time. The simulation of the leakage rate and time of the refrigerant is determined according to different air conditioning systems and refrigerant tank capacities.

[0008] Currently, manual pressure adjustment is usually used to control the leakage amount in the simulation of refrigerant leakage. This scheme cannot accurately control the leakage time and the total leakage amount, and the injection rate fluctuates greatly, which cannot meet the requirements of relevant standards on the total leakage amount, leakage time and injection rate in the simulation of refrigerant leakage. SUMMARY

[0009] The present application solves the problem of providing an automatic control method, device and system for simulating refrigerant leakage.

[0010] In a first aspect, an automatic control method for simulating refrigerant leakage is provided, which is applied in an automatic control system for simulating refrigerant leakage. The system includes a main controller, a gas storage unit, a first injection circuit for injecting refrigerant and a second injection circuit. The lower limit value of the effective range of flow regulation of the second injection circuit is greater than the upper limit value of the effective range of flow regulation of the first injection circuit. The gas storage unit includes a weighing device and a refrigerant tank placed on the weighing device. The main controller is in communication connection with the weighing device. The method includes the following steps:

[0011] If the user inputs the refrigerant type, the set leakage rate and the leakage time, the refrigerant gas density is selected according to the refrigerant type;

[0012] The set volume flow is obtained according to the set leakage rate and the refrigerant gas density;

[0013] A refrigerant injection circuit is selected between the first injection circuit and the second injection circuit according to the set volume flow, and refrigerant injection is performed;

[0014] After the time of this injection reaches the leakage time, the change amount of refrigerant provided by the weighing device is received, and the actual leakage rate of this injection is obtained according to the change amount of refrigerant and the leakage time.

[0015] In a second aspect, an automatic control device for simulating refrigerant leakage is provided, which is used to implement the automatic control method for simulating refrigerant leakage in the first aspect. The method is applied in an automatic control system for simulating refrigerant leakage. The system includes a main controller, a gas storage unit, a first injection circuit for injecting refrigerant and a second injection circuit. The lower limit value of the effective range of flow regulation of the second injection circuit is greater than the upper limit value of the effective range of flow regulation of the first injection circuit. The gas storage unit includes a weighing device and a refrigerant tank placed on the weighing device. The main controller is in communication connection with the weighing device. The automatic control device is configured in the main controller, and the automatic control device includes:

[0016] a density selection module configured to select a refrigerant gas density according to a refrigerant type if the refrigerant type, a set leakage rate and a leakage time are received as user inputs;

[0017] a set volume flow calculation module configured to obtain a set volume flow according to the set leakage rate and the refrigerant gas density;

[0018] a loop selection module configured to select a spray loop between the first spray loop and the second spray loop according to the set volume flow, and spray refrigerant;

[0019] an actual leakage rate calculation module configured to obtain an actual leakage rate of the present spray according to a refrigerant change amount provided by the weighing device and the leakage time after a time of the present spray reaches the leakage time.

[0020] In a third aspect, an embodiment of the present application provides an automatic control system for simulating refrigerant leakage, comprising the automatic control device of the second aspect, and further comprising:

[0021] a gas storage unit comprising a weighing device and a refrigerant tank placed on the weighing device;

[0022] a pressure reduction unit comprising a gas storage tank and a pressure sensor for collecting pressure in the gas storage tank, the gas storage tank being in communication with the refrigerant tank;

[0023] a first spray loop comprising a first pipeline and a first flow controller and a first electromagnetic valve arranged on the first pipeline, the first pipeline being in communication with a first gas outlet of the gas storage tank;

[0024] a second spray loop having a maximum flow greater than that of the first spray loop, the second spray loop comprising a second pipeline and a second flow controller and a second electromagnetic valve arranged on the second pipeline, the second pipeline being in communication with a second gas outlet of the gas storage tank; and

[0025] a main controller in communication with the weighing device, the pressure sensor, the first flow controller, the first electromagnetic valve, the second flow controller and the second electromagnetic valve, the automatic control device being configured in the main controller.

[0026] Beneficial effects: The embodiment of the present application provides an automatic control method, device and system for simulating refrigerant leakage. The method is applied to a system. The system comprises a main controller, a gas storage unit, a first injection circuit for injecting refrigerant and a second injection circuit. The lower limit value of the effective range of flow regulation of the second injection circuit is greater than the upper limit value of the effective range of flow regulation of the first injection circuit. The gas storage unit comprises a weighing device and a refrigerant tank placed on the weighing device. The main controller is in communication connection with the weighing device. The method comprises the following steps: if a user inputs a refrigerant type, a set leakage rate and a leakage time, selecting a refrigerant gas density according to the refrigerant type; obtaining a set volume flow rate according to the set leakage rate and the refrigerant gas density; selecting an injection circuit between the first injection circuit and the second injection circuit according to the set volume flow rate, and injecting refrigerant; after the time of the current injection reaches the leakage time, receiving a refrigerant change amount provided by the weighing device, and obtaining an actual leakage rate of the current injection according to the refrigerant change amount and the leakage time. The automatic control for simulating refrigerant leakage can be realized. By setting the first injection circuit and the second injection circuit with different effective ranges of flow regulation, the wide-range control of flow is realized, the control error is reduced as much as possible, and the control precision is kept within the standard requirement range. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 The flow chart of the automatic control method for simulating refrigerant leakage provided by the embodiment of the present application;

[0029] Figure 2 The schematic diagram of the automatic control system for simulating refrigerant leakage provided by the embodiment of the present application;

[0030] Figure 3 The schematic block diagram of the automatic control device for simulating refrigerant leakage provided by the embodiment of the present application;

[0031] Figure 4 The schematic block diagram of the computer device provided by the embodiment of the present application;

[0032] Figure 5 Another schematic diagram of the automatic control system for simulating refrigerant leakage provided by the embodiment of the present application.

[0033] Mark in the figure:

[0034] 10, gas storage unit; 11, weighing device; 12, refrigerant tank; 13, third electromagnetic valve; 14, pressure reducing valve;

[0035] 20, pressure reducing unit; 21, gas storage tank; 22, pressure sensor; 23, fourth electromagnetic valve;

[0036] 30, first injection circuit; 31, first flow controller; 32, first volume flow meter; 33, first electromagnetic valve; 34, first nozzle;

[0037] 40, second injection circuit; 41, second flow controller; 42, second volume flow meter; 43, second electromagnetic valve; 44, second nozzle. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative effort fall within the scope of protection of the present application.

[0039] It should be understood that, when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0040] It should also be understood that the terms used in the present application specification are only for the purpose of describing particular embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0041] It should be further understood that the term "and / or" used in the present application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0042] It should also be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "joining", "fixing", "setting" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. When an element is referred to as "on" or "under" another element, the element can be "directly" or "indirectly" on the other element, or there can be one or more intervening elements. The terms "first", "second", "third" and the like are only for the convenience of describing the technical solutions, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second", "third" and the like can explicitly or implicitly include one or more of the features. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] Please refer to Figure 1 and Figure 2The embodiment of the present application provides a kind of automatic control method of simulating refrigerant leakage, application in the automatic control system of simulating refrigerant leakage, the system includes main controller, gas storage unit 10, first injection circuit 30 for injecting refrigerant and second injection circuit 40, the lower limit value of the effective range of flow regulation of the second injection circuit 40 is greater than the upper limit value of the effective range of flow regulation of the first injection circuit 30, the gas storage unit 10 includes weighing device 11 and refrigerant tank 12 placed on the weighing device 11, and the main controller is communicated with the weighing device 11.Connection.In the automatic control system of simulating refrigerant leakage, main controller can be CPU in industrial computer.First injection circuit 30 and second injection circuit 40 are two branches of circuit that can carry out flow regulation, wherein the effective range of flow regulation supported by first injection circuit 30 is 0~200L / min, and the effective range of flow regulation supported by second injection circuit 40 is 200~2500L / min (excluding 200), that is, first injection circuit 30 is small flow injection circuit, and second injection circuit 40 is large flow injection circuit.Effective range is determined by the opening range of pipe diameter and valve in the circuit and other devices.It should be noted that effective range refers to the range that can be adjusted by circuit under the premise that the control accuracy is within the standard range, and the error of control is ±5%, that is, the hardware in second injection circuit 40 can adjust the flow in it to below 200L / min, but in this case, it cannot ensure that the error of control accuracy is within the standard range.In this way, by setting first injection circuit 30 and second injection circuit 40, wide-range flow control can be realized, and high-precision flow control can be realized in different subintervals in wide range.Weighing device 11 can be electronic scale, and multiple refrigerant tanks 12 are placed on weighing device 11, which is filled with corresponding types of refrigerant, in the embodiment, before simulating leakage each time, according to the type of refrigerant simulated leakage at this time, multiple refrigerant tanks 12 filled with the type of refrigerant are placed on weighing device 11, for example, R32, R454A, R454B, R454C, R290 and R1234YF etc.flammable refrigerant.The method comprises steps S1~S4.

[0044] S1, if receiving the refrigerant type, set leakage rate and leakage time input by user, the refrigerant gas density is selected according to the refrigerant type.

[0045] If the user inputs the refrigerant type, the set leakage rate and the leakage time, the refrigerant gas density is selected according to the refrigerant type. The user can input the simulated refrigerant type, the set leakage rate and the leakage time to the industrial computer through the touch screen or the keyboard. The user input refrigerant type should be the same as the refrigerant type in the refrigerant tank 12 on the weighing device 11. The industrial computer pre-stores the mapping relationship table of the refrigerant type and the refrigerant gas density. When receiving the user input refrigerant type, the main controller traverses the mapping relationship table according to the refrigerant type to obtain the corresponding refrigerant gas density of the refrigerant type.

[0046] For example, the user input refrigerant type is R32, the set leakage rate is 1.224 g / s, and the leakage time is 60 s. The main controller obtains the corresponding refrigerant gas density of 2.346 kg / m³ according to R32.

[0047] S2, obtain the set volume flow rate according to the set leakage rate and the refrigerant gas density.

[0048] According to the set leakage rate and the refrigerant gas density, the set volume flow rate is obtained. The main controller substitutes the set leakage rate and the refrigerant gas density into the pre-stored volume flow rate calculation formula to obtain the set volume flow rate of this simulation leakage, wherein the volume flow rate calculation formula is:

[0049] Volume flow rate (L / min)=set leakage rate (g / s) x 60 (s) / refrigerant gas density (kg / m³).

[0050] For example, the set volume flow rate=1.224 x 60 / 2.346=31.304 L / min.

[0051] S3, select a spray circuit between the first spray circuit and the second spray circuit according to the set volume flow rate, and spray the refrigerant.

[0052] According to the set volume flow rate, a spray circuit is selected between the first spray circuit 30 and the second spray circuit 40, and the refrigerant is sprayed. The main controller selects the spray circuit with appropriate flow rate according to the calculated set volume flow rate, so as to ensure that the control accuracy is within the standard requirement range, that is, the error is within ±5%.

[0053] In an embodiment, S3, selecting a spray circuit between the first spray circuit and the second spray circuit according to the set volume flow rate, and spraying the refrigerant, can include the following sub-steps:

[0054] determining whether the set volume flow rate is greater than a volume flow rate threshold value;

[0055] If the set volume flow rate is greater than the volume flow rate threshold, an open instruction is sent to the second electromagnetic valve 43 in the second injection circuit 40 and the set volume flow rate is sent to the second flow controller 41 in the second injection circuit 40, so that the second flow controller 41 adjusts the current flow rate in real time.

[0056] If the set volume flow rate is not greater than the volume flow rate threshold, an open instruction is sent to the first electromagnetic valve 33 in the first injection circuit 30 and the set volume flow rate is sent to the first flow controller 31 in the first injection circuit 30, so that the first flow controller 31 adjusts the current flow rate in real time.

[0057] In the embodiment, the volume flow rate threshold can be determined according to the actual pipe diameter and the opening range of the valve and other devices selected by the first injection circuit 30 and the second injection circuit 40, and is pre-stored in the industrial computer. Taking the effective range of flow rate adjustment supported by the first injection circuit 30 as 0-200 L / min and the effective range of flow rate adjustment supported by the second injection circuit 40 as 200-2500 L / min as an example, the volume flow rate threshold can be set as 200 L / min. If the set volume flow rate is greater than the volume flow rate threshold, the second injection circuit 40 is selected as the injection circuit for simulating the leakage this time; if the set volume flow rate is less than or equal to the volume flow rate threshold, the first injection circuit 30 is selected as the injection circuit for simulating the leakage this time. For example, if the set volume flow rate is 31.304 L / min, which is less than 200 L / min, the main controller sends an open instruction to the first electromagnetic valve 33 in the first injection circuit 30 and sends the set volume flow rate to the first flow controller 31 in the first injection circuit 30. In the first injection circuit 30, the first electromagnetic valve 33 is used to control the opening and closing of the circuit, and the first flow controller 31 is used to control the real-time gas flow rate in the circuit. The first flow controller 31 can include a first PID controller and a first proportional valve controlled by the first PID controller. The first PID controller receives the set volume flow rate sent by the main controller and adjusts the current gas flow rate in the first injection circuit 30 in real time according to the set volume flow rate, so as to realize precise control of the flow rate.

[0058] For example, if the set volume flow rate is set to 1000 L / min, which is greater than 200 L / min, the main controller sends an open command to the second electromagnetic valve 43 in the second injection circuit 40 and sends the set volume flow rate to the second flow controller 41 in the second injection circuit 40. In the second injection circuit 40, the second electromagnetic valve 43 is used to control the opening and closing of the circuit, and the second flow controller 41 is used to control the size of the real-time gas flow in the circuit. The second flow controller 41 can include a second PID controller and a second proportional valve that can be controlled by the second PID controller. The second PID controller receives the set volume flow rate sent by the main controller and adjusts the current gas flow in the second injection circuit 40 in real time according to the set volume flow rate to achieve precise control of the flow.

[0059] To avoid the calculated set volume flow rate being greater than the upper limit of the effective range of the flow adjustment of the second injection circuit 40, the user can input the set leakage rate in a selected manner instead of directly inputting it. Specifically, since the number of refrigerant types in the pre-stored mapping relationship table of refrigerant types and refrigerant gas densities in the industrial computer is limited, the minimum value of the refrigerant gas density can be obtained from it. The minimum value of the refrigerant gas density in the mapping relationship table and the upper limit of the effective range of the flow adjustment of the second injection circuit 40 are substituted into the above-mentioned volume flow rate calculation formula to calculate the maximum value of the set leakage rate that the user can select. In this way, precise control of the flow by the second injection circuit 40 can be ensured.

[0060] In an embodiment, the second flow controller adjusts the current flow in real time, including the following sub-steps:

[0061] The second flow controller 41 receives the real-time volume flow rate collected by the second volume flow meter 42 in the second injection circuit 40 and determines whether the real-time volume flow rate is greater than the set volume flow rate. If the real-time volume flow rate is greater than the set volume flow rate, the second flow controller 41 controls the opening of the proportional valve inside it to decrease. If the real-time volume flow rate is not greater than the set volume flow rate, the second flow controller 41 controls the opening of the proportional valve inside it to increase.

[0062] In this embodiment, when the second injection circuit 40 is selected as the injection circuit for the current simulation leakage, the second PID controller receives the set volume flow rate sent by the main controller and the real-time volume flow rate collected by the second volume flow meter 42, and determines the size of the real-time volume flow rate and the set volume flow rate. If the real-time volume flow rate is greater than the set volume flow rate, the second proportional valve is sent a command to decrease the opening. If the real-time volume flow rate is not greater than the set volume flow rate, the second proportional valve is sent a command to increase the opening to achieve precise control of the flow, so that the real-time flow rate remains near the set volume flow rate, for example, within 5% above and below the set volume flow rate.

[0063] In an embodiment, the first flow controller adjusts the current flow in real time, including the following sub-steps:

[0064] The first flow controller 31 receives the real-time volume flow collected by the first volume flow meter 32 in the first injection circuit 30, and determines whether the real-time volume flow is greater than the set volume flow; if the real-time volume flow is greater than the set volume flow, the first flow controller 31 controls the opening of the proportional valve inside to decrease; if the real-time volume flow is not greater than the set volume flow, the first flow controller 31 controls the opening of the proportional valve inside to increase.

[0065] In this embodiment, when the first injection circuit 30 is selected as the injection circuit for simulating leakage this time, the first PID controller receives the set volume flow sent by the main controller and the real-time volume flow collected by the first volume flow meter 32, and determines the size of the real-time volume flow and the set volume flow; if the real-time volume flow is greater than the set volume flow, the first PID controller sends a command to decrease the opening of the first proportional valve; if the real-time volume flow is not greater than the set volume flow, the first PID controller sends a command to increase the opening of the first proportional valve, so as to realize precise control of the flow.

[0066] S4, after the time of the current injection reaches the leakage time, receiving the change amount of refrigerant provided by the weighing device, and obtaining the actual leakage rate of the current injection according to the change amount of refrigerant and the leakage time.

[0067] In this embodiment, after the time of the current injection reaches the leakage time, the main controller first sets the flow to stop output, and then controls the electromagnetic valve to close, for example, the main controller first sends a command to the first PID controller to stop output, and then sends a command to the first electromagnetic valve 33 to close (or the main controller first sends a command to the second PID controller to stop output, and then sends a command to the second electromagnetic valve 43 to close). The change amount of refrigerant provided by the weighing device 11 is received, for example, the weight information collected by the weighing device 11 is obtained once before S1, and the weight information collected by the weighing device 11 is obtained again after the time of the current injection reaches the leakage time, and the difference between the two weight information is calculated to obtain the change amount of refrigerant. The actual leakage rate of the current injection can be obtained based on the following formula:

[0068] Actual leakage rate (g / s) = change amount of refrigerant (g) / leakage time (s).

[0069] Therefore, the automatic control method for simulating refrigerant leakage provided by the embodiment of the present application can realize automatic control of simulating refrigerant leakage, and by setting the first injection circuit 30 and the second injection circuit 40 with different effective ranges of flow regulation, the control error can be reduced as much as possible while realizing wide-range control of flow, so that the control accuracy can be kept within the standard requirement range.

[0070] In an embodiment, the automatic control method for simulating refrigerant leakage further comprises, after the actual leakage rate of the current injection is obtained:

[0071] S5, judging whether the leakage error is within the preset range according to the actual leakage rate and the set leakage rate.

[0072] S6, if the leakage error is within the preset range, sending a result that the current control meets the set accuracy to the display.

[0073] In the embodiment, after the main controller obtains the actual leakage rate of the current injection, the leakage error of the current simulation leakage can be calculated by the following formula:

[0074] Leakage error = (actual leakage rate - set leakage rate) / set leakage rate x 100%.

[0075] And it is judged whether the calculated leakage error is within [-5%, +5%], if it is within [-5%, +5%], a result that the current control meets the set accuracy is sent to the display to realize verification of the control accuracy and increase the guarantee of accurate flow control.

[0076] If the leakage error is not within the preset range, a result that the current control does not meet the set accuracy is sent to the display to remind the staff to adjust the system until the leakage error is within the preset range, so as to avoid misassessment caused by the installation position of the refrigerant gas sensor.

[0077] In an embodiment, the system further comprises a pressure reduction unit 20, the pressure reduction unit 20 comprises a gas storage tank 21 and a pressure sensor 22 for collecting the pressure in the gas storage tank 21, the gas storage tank 21 is in communication with the refrigerant tank 12; after the injection circuit is selected according to the set volume flow between the first injection circuit 30 and the second injection circuit 40 for refrigerant injection, the method further comprises:

[0078] S31, if the pressure signal collected by the pressure sensor is received, judging whether the pressure signal is between the lower pressure threshold and the upper pressure threshold.

[0079] S32, if the pressure signal is not between the lower pressure threshold and the upper pressure threshold, sending an alarm instruction to the reminding device.

[0080] In the embodiment, the pressure reduction unit 20 is arranged between the gas storage unit 10 and the first injection circuit 30 (the second injection circuit 40), specifically, the gas inlet of the gas storage tank 21 is communicated with the gas outlet of the refrigerant tank 12, the first gas outlet of the gas storage tank 21 is communicated with the first injection circuit 30, and the second gas outlet of the gas storage tank 21 is communicated with the second injection circuit 40, that is, when the refrigerant is injected, the refrigerant is discharged from the refrigerant tank 12 first into the gas storage tank 21, and when the refrigerant in the gas storage tank 21 reaches a certain amount, the refrigerant is injected into the first injection circuit 30 (the second injection circuit 40). The reminding device can be an indicator light or a buzzer.

[0081] Specifically, in the process of refrigerant injection, as the refrigerant in the refrigerant tank 12 continuously evaporates, the temperature thereof rapidly decreases, which affects the evaporation amount of the refrigerant and causes the refrigerant gas to be unable to be quickly replenished. Therefore, the gas storage tank 21 is arranged to store a certain amount of refrigerant, so as to maintain the pressure of the refrigerant gas source stable in the process of refrigerant injection. The pressure sensor 22 of the gas storage unit 10 is used to monitor the pressure of the gas storage tank 21, and when the pressure is too large or too small, the alarm of the system is triggered, because when the pressure is too large and exceeds the upper limit of the operating pressure of the gas storage tank 21, the gas storage tank 21 may be broken or leak, and the equipment may be damaged. When the pressure is too small, the flow control is affected, the specified control flow cannot be achieved, and finally the injection flow of the refrigerant is small.

[0082] In addition, the pressure reduction unit 20 further comprises a fourth electromagnetic valve 23 arranged on a pipeline communicated with the third gas outlet of the gas storage tank 21. When the pressure signal exceeds the upper limit threshold of the pressure, the main controller sends an opening instruction to the fourth electromagnetic valve 23, for example, when the pressure signal exceeds 600 Kpa, the refrigerant gas in the gas storage tank 21 is discharged, so as to avoid safety accidents.

[0083] If the pressure signal is between the lower limit threshold and the upper limit threshold of the pressure, no alarm instruction is sent to the reminding device. Meanwhile, when the main controller sends the alarm instruction to the reminding device, a closing instruction is further sent to the first electromagnetic valve 33 or the second electromagnetic valve 43, so as to quickly cut off the injection of the refrigerant, and prevent the occurrence and spread of danger.

[0084] Please refer to Figure 3 The embodiment of the present application further provides an automatic control device 100 for simulating refrigerant leakage, which is used to realize the automatic control method for simulating refrigerant leakage in the above embodiment, and is arranged in the main controller. The automatic control device 100 comprises:

[0085] A density selection module 110 is configured to select the density of the refrigerant gas according to the refrigerant type if the refrigerant type, the set leakage rate and the leakage time input by the user are received.

[0086] The set volume flow calculation module 120 is configured to obtain a set volume flow according to the set leakage rate and the refrigerant gas density;

[0087] The loop selection module 130 is configured to select a spray loop between the first spray loop 30 and the second spray loop 40 according to the set volume flow, and perform refrigerant spraying.

[0088] The actual leakage rate calculation module 140 is configured to receive a refrigerant change amount provided by the weighing device 11 after a time of the current spraying reaches the leakage time, and obtain an actual leakage rate of the current spraying according to the refrigerant change amount and the leakage time.

[0089] In an embodiment, the automatic control device further comprises:

[0090] The error judgment module 150 is configured to judge whether a leakage error is within a preset range according to the actual leakage rate and the set leakage rate.

[0091] The result sending module 160 is configured to send a result that the current control meets a set accuracy to a display if the leakage error is within the preset range.

[0092] In an embodiment, the automatic control device further comprises:

[0093] The pressure judgment module 131 is configured to judge whether a pressure signal collected by the pressure sensor 22 is between a pressure lower threshold and a pressure upper threshold if the pressure signal is received.

[0094] The alarm instruction sending module 132 is configured to send an alarm instruction to a reminding device if the pressure signal is not between the pressure lower threshold and the pressure upper threshold.

[0095] The automatic control device for simulating refrigerant leakage can be implemented in the form of a computer program, which can run on a computer device as shown in the accompanying drawings. Figure 4

[0096] Please refer to Figure 4 , Figure 4 is a schematic block diagram of a computer device provided by an embodiment of the present application, and the computer device can be an industrial computer.

[0097] The computer device 500 includes a processor 502, a memory, and a network interface 505 connected through a communication bus 501, wherein the memory can include a storage medium 503 and an internal memory 504.

[0098] ​The storage medium 503 can store an operating system 5031 and a computer program 5032. The computer program 5032, when executed, can cause the processor 502 to perform the automatic control method for simulating refrigerant leakage. The storage medium 503 can be a volatile storage medium or a non-volatile storage medium.

[0099] The processor 502 is configured to provide computing and control capabilities to support the operation of the entire computer device 500.

[0100] The internal storage 504 provides an environment for the execution of the computer program 5032 in the storage medium 503. The computer program 5032, when executed by the processor 502, can cause the processor 502 to perform the automatic control method for simulating refrigerant leakage.

[0101] The network interface 505 is configured to perform network communication, such as providing transmission of data information, and the like. Those skilled in the art can understand that the network interface 505 can be configured to perform network communication by using a wired or wireless communication technology. Figure 4 The structure shown in FIG. 5 is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device 500 to which the scheme of the present application is applied. Specifically, the computer device 500 can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0102] The processor 502 is configured to run the computer program 5032 stored in the memory to implement the corresponding functions in the automatic control method for simulating refrigerant leakage described above.

[0103] Those skilled in the art can understand that the computer device 500 shown in FIG. 5 is only a specific example of the computer device, and the present application is not limited to the computer device shown in FIG. 5. Figure 4 The embodiments of the computer device shown in FIG. 5 do not constitute a limitation on the specific structure of the computer device. In other embodiments, the computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. For example, in some embodiments, the computer device can only include a memory and a processor. In such embodiments, the structure and functions of the memory and the processor are consistent with those of the embodiments shown in FIG. 5, and will not be described here. Figure 4 The embodiments of the computer device shown in FIG. 5 do not constitute a limitation on the specific structure of the computer device. In other embodiments, the computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. For example, in some embodiments, the computer device can only include a memory and a processor. In such embodiments, the structure and functions of the memory and the processor are consistent with those of the embodiments shown in FIG. 5, and will not be described here.

[0104] It should be understood that, in the embodiments of the present application, the processor 502 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0105] In another embodiment of the present application, a computer readable storage medium is provided. The computer readable storage medium can be a volatile or non-volatile computer readable storage medium. The computer readable storage medium stores a computer program, wherein the computer program is executed by a processor to implement the steps included in the automatic control method for simulating refrigerant leakage.

[0106] Referring to Figure 2 The embodiment of the present application further provides an automatic control system for simulating refrigerant leakage, comprising the automatic control device provided in the above embodiment, and further comprising:

[0107] The gas storage unit 10 comprises a weighing device 11 and a refrigerant tank 12 placed on the weighing device 11;

[0108] The pressure reduction unit 20 comprises a gas storage tank 21 and a pressure sensor 22 for collecting the pressure in the gas storage tank 21, and the gas storage tank 21 is in communication with the refrigerant tank 12;

[0109] The first injection circuit 30 comprises a first pipeline, a first flow controller 31 and a first electromagnetic valve 33 arranged on the first pipeline, and the first pipeline is in communication with a first gas outlet of the gas storage tank 21;

[0110] The second injection circuit 40 has a maximum flow greater than that of the first injection circuit 30, and comprises a second pipeline, a second flow controller 41 and a second electromagnetic valve 43 arranged on the second pipeline, and the second pipeline is in communication with a second gas outlet of the gas storage tank 21; and

[0111] The main controller is in communication connection with the weighing device 11, the pressure sensor 22, the first flow controller 31, the first electromagnetic valve 33, the second flow controller 41 and the second electromagnetic valve 43, and the automatic control device is arranged in the main controller.

[0112] In this embodiment, when a large flow of refrigerant is injected, the single bottle refrigerant tank 12 cannot reach the corresponding large flow output due to the small diameter of the outlet. In the gas storage unit 10, multiple standard refrigerant tanks 12 are connected to the large-diameter gas outlet at the same time, specifically four or more refrigerant tanks 12 simultaneously supplement the gas storage unit 10 with gas. At the same time, four or more refrigerant tanks 12 are placed on a high-precision electronic scale, and the total mass of the refrigerant injection can be obtained by reading the weight change on the electronic scale after each refrigerant injection is completed.

[0113] In an embodiment, the gas storage unit 10 further comprises a third solenoid valve 13 and a pressure reducing valve 14, the third solenoid valve 13 and the pressure reducing valve 14 are arranged on the pipeline communicating the gas inlet of the refrigerant tank 12 and the gas storage tank 21, the third solenoid valve 13 is in communication connection with the main controller; the pressure reducing unit 20 further comprises a fourth solenoid valve 23, the fourth solenoid valve 23 is arranged on the pipeline communicating with the third gas outlet of the gas storage tank 21.

[0114] In this embodiment, the third solenoid valve 13 is used to control the input of the gas source, and the system can cut off the gas source of the refrigerant by quickly closing the third solenoid valve 13 after detecting a fault or related alarm, to prevent the occurrence and spread of danger. The pressure reducing valve 14 reduces the refrigerant pressure of about 1Mpa to 80Kpa-120Kpa, and then fills the gas storage tank 21 of the gas storage unit 10; the pressure of the refrigerant is reduced in order to completely gasify the compressed gas of the refrigerant, to prevent the occurrence of liquid injection, resulting in inaccurate flow control and measurement.

[0115] In an embodiment, the first injection circuit 30 further comprises a first volumetric flow meter 32 arranged on the first pipeline, and the first volumetric flow meter 32 is in communication connection with the first flow controller 31; the second injection circuit 40 further comprises a second volumetric flow meter 42 arranged on the second pipeline, and the second volumetric flow meter 42 is in communication connection with the second flow controller 41.

[0116] In this embodiment, the first injection circuit 30 can further comprise a first nozzle 34 arranged at the outlet end of the first pipeline. The second injection circuit 40 can further comprise a second nozzle 44 arranged at the outlet end of the second pipeline. The diameter of the first nozzle 34 and the second nozzle 44 is also one of the effective range of hardware parameters affecting the flow regulation. The diameter of the second nozzle 44 is larger than that of the first nozzle 34. The different sizes of the nozzles ensure the smooth discharge of the refrigerant gas during the injection process, which helps to stabilize the injection of the gas flow.

[0117] As Figure 5As shown, in an embodiment, the automatic control system for simulating refrigerant leakage further comprises a power supply unit, a state indicating unit and a control unit.

[0118] In the embodiment, the entire automatic control system is powered by 220VAC mains, with a power of about 1KW. After the mains input, the circuit breaker of the power supply unit provides overcurrent and leakage protection, and then powers the industrial computer, the display, the serial server and the low-voltage power module.

[0119] The low-voltage power module of the power supply unit is responsible for converting the 220VAC mains voltage into a 24VDC low-voltage power supply, which is responsible for powering the electronic scale, the flow controller, the pressure sensor, the refrigerant sensor, the IO expansion module, the 4-way electromagnetic valve and the run, stop and fault indicator lights.

[0120] The emergency stop button is responsible for cutting off the 220VAC mains voltage to the low-voltage power module. When the emergency stop button is pressed, the underlying control is completely powered off, and the inputs and outputs of each gas circuit are in a completely closed state. The fourth electromagnetic valve 23 of the gas storage unit 10 is opened to release the pressure in the gas storage tank 21.

[0121] The state indicating unit consists of four system state indicator lights, namely the power, run, stop and fault indicator lights. The power indicator light is directly connected to the output of the circuit breaker of the power supply unit, and is used to indicate the connection status of the system power. The remaining three state indicator lights are controlled by the industrial computer through the IO expansion module, and are used to indicate the working state of the system at that time.

[0122] Figure 5 The serial server and the IO expansion module in the serial server are intermediate devices for data transmission. All acquisition and control data of the industrial computer need to be forwarded to the underlying acquisition or control device after data and protocol processing through these two devices. The serial server is connected with the industrial computer through an RJ45 Ethernet interface; the electronic scale, the flow controller, the pressure sensor and the refrigerant sensor are connected with the serial server through an RS485 bus; the IO expansion module is connected with the industrial computer through an RS232 bus, and the IO expansion module internally uses a wet node composed of power relays to control the 3-way indicator lights and the 4-way electromagnetic valve.

[0123] The control unit is the system and user interaction window and the center of data processing and operation, which consists of a display, an industrial computer and a human-computer interaction interface. The system control software is installed on the industrial control computer and is run by it.

[0124] The application scenarios of the automatic control system for simulating refrigerant leakage provided by the embodiment of the application are as follows:

[0125] Air conditioner and heat pump manufacturers can use the system to evaluate the installation location of refrigerant gas sensors by simulating refrigerant leaks. Certification and testing agencies can use the system to evaluate whether an air conditioning system can effectively alert and trigger the appropriate action within the time specified by the standard after a refrigerant leak. Refrigerant gas sensor manufacturers can use the system to evaluate the response time of refrigerant gas sensors in real-world applications.

[0126] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the devices, apparatuses and units described above can refer to the corresponding processes in the foregoing method embodiments, which will not be described here. Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been described in the foregoing description in a general manner. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0127] In several embodiments provided by the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the apparatus embodiments described above are only schematic. For example, the division of the units is only a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can also be electrical, mechanical or other forms of connection.

[0128] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present application.

[0129] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or software functional unit.

[0130] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part of the prior art that contributes, or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a computer readable storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. And the aforementioned computer readable storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0131] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An automatic control method of simulating refrigerant leakage, characterized by, In an automatic control system simulating refrigerant leakage, the system includes a main controller, a gas storage unit, a first injection circuit for injecting refrigerant, and a second injection circuit. The lower limit of the effective range of flow regulation in the second injection circuit is greater than the upper limit of the effective range of flow regulation in the first injection circuit. The gas storage unit includes a weighing device and a refrigerant tank placed on the weighing device. The main controller is communicatively connected to the weighing device. The method includes: If the user inputs the type of refrigerant, the set leakage rate, and the leakage time, the refrigerant gas density is selected according to the type of refrigerant. The set volumetric flow rate is obtained based on the set leakage rate and the set refrigerant gas density; Based on the set volumetric flow rate, a refrigerant injection circuit is selected between the first injection circuit and the second injection circuit; After the leakage time is reached during this injection, the change in refrigerant provided by the weighing device is received, and the actual leakage rate of this injection is obtained based on the change in refrigerant and the leakage time.

2. The automatic control method of simulating refrigerant leakage according to claim 1, wherein The step of selecting an injection circuit between the first injection circuit and the second injection circuit according to the set volumetric flow rate for refrigerant injection includes: Determine whether the set volumetric flow rate is greater than the volumetric flow rate threshold; If the set volume flow rate is greater than the volume flow rate threshold, an opening command is sent to the second solenoid valve in the second injection circuit and the set volume flow rate is sent to the second flow controller in the second injection circuit so that the second flow controller can adjust the current flow rate in real time. If the set volumetric flow rate is not greater than the volumetric flow rate threshold, an opening command is sent to the first solenoid valve in the first injection circuit and the set volumetric flow rate is sent to the first flow controller in the first injection circuit so that the first flow controller can adjust the current flow rate in real time.

3. The automatic control method of simulating a refrigerant leakage according to claim 2, characterized by, The second flow controller adjusts the current flow in real time, including: The second flow controller receives the real-time volumetric flow rate collected by the second volumetric flow meter in the second injection circuit and determines whether the real-time volumetric flow rate is greater than the set volumetric flow rate. If the real-time volumetric flow rate is greater than the set volumetric flow rate, the second flow controller controls the opening of its internal proportional valve to decrease. If the real-time volumetric flow rate is not greater than the set volumetric flow rate, the second flow controller controls the opening of its internal proportional valve to increase.

4. The automatic control method of simulating refrigerant leakage according to claim 2, wherein The first flow controller adjusts the current flow in real time, including: The first flow controller receives the real-time volumetric flow rate collected by the first volumetric flow meter in the first injection circuit and determines whether the real-time volumetric flow rate is greater than the set volumetric flow rate. If the real-time volumetric flow rate is greater than the set volumetric flow rate, the opening of the proportional valve inside the first flow controller is reduced; If the real-time volumetric flow rate is not greater than the set volumetric flow rate, the first flow controller controls the opening of its internal proportional valve to increase.

5. The automatic control method of simulating refrigerant leakage according to claim 1, wherein After obtaining the actual leakage rate of this injection, the following is included: determining whether the leakage error is within a preset range according to the actual leakage rate and the set leakage rate; if the leakage error is within the preset range, sending a result that this time control meets the set accuracy to a display.

6. The automatic control method of simulating refrigerant leakage according to claim 1, wherein The system further comprises a pressure reduction unit, which comprises a gas storage tank and a pressure sensor for collecting pressure in the gas storage tank, and the gas storage tank is in communication with the refrigerant tank; and after selecting a spray circuit between the first spray circuit and the second spray circuit according to the set volume flow rate and performing refrigerant spraying, the system further comprises: if the pressure signal collected by the pressure sensor is received, determining whether the pressure signal is between a lower pressure threshold and an upper pressure threshold; if the pressure signal is not between the lower pressure threshold and the upper pressure threshold, sending an alarm instruction to a reminding device.

7. An automatic control device for simulating refrigerant leakage, characterized in that, An automatic control method for simulating refrigerant leakage according to any one of claims 1 to 6 is applied in an automatic control system for simulating refrigerant leakage, the system comprising a main controller, a gas storage unit, a first spray circuit and a second spray circuit for spraying refrigerant, the lower limit value of the effective range of flow rate adjustment of the second spray circuit being greater than the upper limit value of the effective range of flow rate adjustment of the first spray circuit, the gas storage unit comprising a weighing device and a refrigerant tank placed on the weighing device, the main controller being in communication connection with the weighing device, and the automatic control device being arranged in the main controller, the automatic control device comprising: a density selection module for selecting refrigerant gas density according to a refrigerant type if the refrigerant type, a set leakage rate and a leakage time input by a user are received; a set volume flow rate calculation module for obtaining a set volume flow rate according to the set leakage rate and the refrigerant gas density; a circuit selection module for selecting a spray circuit between the first spray circuit and the second spray circuit according to the set volume flow rate to perform refrigerant spraying; an actual leakage rate calculation module for receiving a refrigerant change amount provided by the weighing device after the time of this time spraying reaches the leakage time, and obtaining an actual leakage rate of this time spraying according to the refrigerant change amount and the leakage time.

8. An automatic control system simulating a refrigerant leakage, characterized by, The system further comprises: a gas storage unit comprising a weighing device and a refrigerant tank placed on the weighing device; a pressure reduction unit comprising a gas storage tank and a pressure sensor for collecting pressure in the gas storage tank, and the gas storage tank is in communication with the refrigerant tank; a first spray circuit comprising a first pipeline and a first flow rate controller and a first electromagnetic valve arranged on the first pipeline, and the first pipeline is in communication with a first gas outlet of the gas storage tank; a second spray circuit, the maximum flow rate of which is greater than that of the first spray circuit, the second spray circuit comprising a second pipeline and a second flow rate controller and a second electromagnetic valve arranged on the second pipeline, and the second pipeline is in communication with a second gas outlet of the gas storage tank; and a second spray circuit, the maximum flow rate of which is greater than that of the first spray circuit, the second spray circuit comprising a second pipeline and a second flow rate controller and a second electromagnetic valve arranged on the second pipeline, and the second pipeline is in communication with a second gas outlet of the gas storage tank; and A main controller, in communication connection with the weighing device, the pressure sensor, the first flow controller, the first electromagnetic valve, the second flow controller and the second electromagnetic valve, is configured in the automatic control device.

9. The automatic control system simulating refrigerant leakage according to claim 8, wherein The gas storage unit further comprises a third electromagnetic valve and a pressure reducing valve, the third electromagnetic valve and the pressure reducing valve are arranged on a pipeline communicating with a gas inlet of the gas storage tank, the third electromagnetic valve is in communication connection with the main controller; the pressure reducing unit further comprises a fourth electromagnetic valve, the fourth electromagnetic valve is arranged on a pipeline communicating with a third gas outlet of the gas storage tank.

10. The automatic control system simulating refrigerant leakage according to claim 8, wherein The first injection circuit further comprises a first volume flow meter arranged on the first pipeline, the first volume flow meter is in communication connection with the first flow controller; the second injection circuit further comprises a second volume flow meter arranged on the second pipeline, the second volume flow meter is in communication connection with the second flow controller.

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