A hot surface ignition temperature test device for flammable refrigerants

Abstract

The utility model discloses a hot surface ignition temperature test device for flammable refrigerants, belonging to the technical field of flammable refrigerant testing; a heating plate is arranged on the upper surface of the heating table of the surface heating unit, a spray pipe of the refrigerant supply unit extends to the top of the heating plate, a first valve member is arranged at the connection between the first end of the spray pipe and the refrigerant tank, and a second valve member is arranged near the second end of the spray pipe. During the test, the test controller controls the airflow supply unit to establish a stable air flow environment on the upper surface of the heating table, controls the heating plate to heat to the initial set temperature and maintains it through the temperature adjustment switch, and then sprays the refrigerant to the surface of the heating table in the isolation tube space through the spray pipe, and observes whether the refrigerant ignites within the set temperature to determine the hot surface ignition temperature of the refrigerant. This test device and test method can effectively improve the accuracy of the hot surface ignition temperature test, reduce the amount of refrigerant used in a single test, reduce the pollution caused by the test, and improve the safety of the test.

Description

Technical Field

[0001] The utility model relates to the technical field of flammable refrigerant testing, in particular to a hot surface ignition temperature testing device for flammable refrigerants. Background Art

[0002] As people pay more attention to environmental issues, refrigerant replacement has become the most urgent issue in the refrigeration and air-conditioning industry. Some environmentally friendly refrigerants with 0 ODP value and low GWP value are gradually favored by the refrigeration and air-conditioning industry and become substitutes for non-environmentally friendly refrigerants such as HFC and HCFC.

[0003] However, since most of the alternative refrigerants commonly used in the refrigeration and air-conditioning industry, such as R32 and R290, are flammable refrigerants, their application in air-conditioning products has made the safety of the air conditioner itself one of the problems that the industry urgently needs to solve. The use of flammable refrigerants makes some high-temperature components in refrigeration or air-conditioning heat pump products potential ignition sources, which may become ignition sources in the event of refrigerant leakage and cause the risk of ignition. At present, the safety standards for refrigerators, commercial freezers and air conditioners all have requirements for high-temperature surface temperatures, usually based on the auto-ignition temperature of the refrigerant minus 100K. In 2022, the new version of the air conditioner safety standard IEC 60335-2-40:2022 was released, which appropriately relaxed this condition, and the temperature limit is the auto-ignition temperature or the measured hot surface ignition temperature minus 100K.

[0004] For some new refrigerants, it is impossible to determine their self-ignition temperature, and it is necessary to measure the hot surface ignition temperature through experimental means. At present, the equipment system used for this test has a complex structure and is greatly affected by external airflow. The hot surface ignition temperature of the tested refrigerant has low accuracy, and the amount of refrigerant used in a single test is large. During the test, it is easy to diffuse to the outside world and cause great pollution and poor safety. It cannot meet the test needs of testing the hot surface ignition temperature of flammable refrigerants in the factory. Summary of the invention

[0005] Based on this, the utility model provides a hot surface ignition temperature test device for flammable refrigerants to improve the accuracy of hot surface ignition temperature testing, reduce the amount of refrigerant used in a single test, reduce pollution caused by the test, and improve test safety.

[0006] In order to achieve the above-mentioned purpose, in a first aspect, the utility model provides a hot surface ignition temperature test device for flammable refrigerants, comprising a surface heating unit, a refrigerant supply unit and a test controller; the surface heating unit comprises a heating table, an isolation tube, a temperature adjustment switch and a temperature sensor, a heating plate is arranged on the upper surface of the heating table, the isolation tube cover is arranged outside the heating plate, the temperature adjustment switch is control-connected to the heating plate, and the temperature sensor monitors the temperature of the heating plate; the refrigerant supply unit comprises a refrigerant tank, a spray pipe, a first valve component and a second valve component, the first end of the spray pipe is connected to the refrigerant tank, and the second end extends to above the heating plate, the first valve component is arranged at the connection between the first end of the spray pipe and the refrigerant tank, and the second valve component is arranged near the second end of the spray pipe; the test controller is control-connected to the surface heating unit and the refrigerant supply unit.

[0007] Optionally, the spray pipe includes a first pipe section arranged between the first valve member and the second valve member and a second pipe section arranged at the rear end of the second valve member, the first pipe section is provided with a space for storing liquid refrigerant for a single test, and the end of the second pipe section extends vertically and is arranged at a distance from the center of the heating plate.

[0008] Optionally, the test controller is controlled and connected to the first valve component and the second valve component, and the test controller is configured to control the first valve component to close after delivering liquid refrigerant to the first pipe joint, and control the second valve component to open when the first valve component is closed to spray refrigerant onto the surface of the heating plate.

[0009] Optionally, the isolation tube is arranged vertically outside the heating plate, an air circulation gap is left between the lower end of the isolation tube and the upper surface of the heating platform, and the second pipe section extends from the center of the isolation tube to the vicinity of the heating plate.

[0010] Optionally, a portion of the upper surface of the heating platform outside the heating plate is covered with a heat insulation layer, the isolation tube is vertically arranged above the heat insulation layer, and the air circulation gap is provided between the lower end of the isolation tube and the heat insulation layer.

[0011] Optionally, the temperature sensor includes at least one thermocouple, and the at least one thermocouple is fixedly mounted on the bottom side of the heating plate, and the test controller is provided with a display connected to the at least one thermocouple.

[0012] Optionally, the test device is further provided with an air flow supply unit, the air flow supply unit comprising an air supply pipe and an air supply pump, the air supply pipe surrounds the vicinity of the bottom of the isolation cylinder and is connected to the air supply pump, and the air supply pipe array is provided with an air discharge port toward the air circulation gap;

[0013] The test controller is connected to the air flow supply unit for controlling. The test controller is configured to control the air supply pump to provide air flow to the surface of the heating plate through the air circulation gap, so as to establish a stable air flow environment during the test.

[0014] Optionally, the test device is further provided with a post-processing unit, the post-processing unit comprising an air recovery pipe, a recovery pump, a recovery tank and a lifting mechanism, the recovery tank is connected to the air recovery pipe through the recovery pump, the front end of the air recovery pipe is movably arranged in the isolation cylinder, and the lifting mechanism is drivingly connected to the air recovery pipe;

[0015] The test controller is connected to the post-processing unit control. The test controller is configured to control the lifting mechanism to drive the front end of the air recovery pipe to move up and down and reciprocate in the isolation cylinder after the test is completed, and control the recovery pump to suck the gas in the isolation cylinder through the air recovery pipe.

[0016] In order to achieve the above-mentioned object, in a second aspect, the utility model provides a hot surface ignition temperature test device and a test method for flammable refrigerants, characterized in that it includes:

[0017] S100. The test controller controls the air supply unit to deliver air to the isolation passage through the air flow gap at a set air flow rate, thereby establishing a stable air flow environment on the surface of the heating table;

[0018] S200. Control the heating plate to heat to the initial set temperature and maintain it through the temperature adjustment switch;

[0019] S300. Control the first valve to open and deliver liquid refrigerant for a single test to the first pipe section of the spray pipe and then close it, and then open the second valve to spray the refrigerant on the surface of the heating platform in the isolation tube space;

[0020] S400. Observe whether the refrigerant ignites within the set temperature;

[0021] S500. If ignition does not occur, the refrigerant in the isolation cylinder is removed by the post-processing unit; then, the temperature is increased by a set amplitude based on the initial set temperature, and S200a-S400a is repeated;

[0022] S600. If ignition occurs, the temperature of the heating plate is reduced by a set amplitude and maintained. If no ignition occurs after repeating S200-S500 for a set number of times, the temperature before reduction is determined to be the hot surface ignition temperature.

[0023] Optionally, the method further comprises:

[0024] S700. The test controller controls the air supply unit to change the air flow rate between the isolation cylinder and the upper surface of the heating table to change the air flow environment;

[0025] S800. Repeat S200-S600 to test the hot surface ignition temperature after changing the air flow environment.

[0026] The technical advantages of the hot surface ignition temperature test device and test method for flammable refrigerants provided are at least reflected in:

[0027] On the first aspect, the surface heating unit is provided with a heating plate controlled by a temperature regulating switch on the surface of the heating table, and an isolation tube is provided outside the heating plate. During the test, a stable air flow environment is constructed in the isolation tube cover, and a hot surface environment with precise temperature is created through the heating plate, thereby reducing the influence of the external environment. The flammable refrigerant is accurately sprayed above the heating plate in the isolation tube, and the hot surface ignition temperature is tested in the above-mentioned air flow environment and hot surface environment in the isolation tube cover, thereby improving the accuracy of the hot surface ignition temperature and preventing the occurrence of environmental pollution problems caused by the external diffusion of flammable refrigerant during the test;

[0028] On the second aspect, the refrigerant supply unit is provided with a space for storing liquid refrigerant for a single test by arranging a first valve member and a second valve member at intervals on the spray pipe, and a first pipe section between the first valve member and the second valve member. During the test, the first valve member is controlled to deliver liquid refrigerant to the first pipe section and then close, and the second valve member is controlled to open when the first valve member is closed to spray refrigerant onto the surface of the heating plate, so that the small-dose use of refrigerant for a single test is accurately controlled, and two barriers of the first valve member and the second valve member are established between the end of the spray pipe and the refrigerant tank to avoid simultaneous opening control, thereby improving the safety of the test process;

[0029] Thirdly, the test control unit is connected to the surface heating unit and the refrigerant supply unit, monitors the test temperature in real time through the temperature sensor, controls the temperature of the heating plate through the temperature adjustment switch, and controls the supply of flammable refrigerant through the first valve member and the second valve member. It is suitable for repeated tests and can meet the test needs of testing the ignition temperature of the hot surface of flammable refrigerant in the factory. It has the characteristics of simple operation, safe and controllable process, and accurate test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0031] The present invention can be more clearly understood from the following detailed description with reference to the accompanying drawings, wherein:

[0032] Figure 1 A schematic structural diagram of an embodiment of a hot surface ignition temperature test device for flammable refrigerants provided;

[0033] Figure 2 A system block diagram of an embodiment of a hot surface ignition temperature test device for flammable refrigerants;

[0034] Figure 3 A flowchart of an embodiment of a method for testing the ignition temperature of a flammable refrigerant using a hot surface is provided;

[0035] Figure 4 A flowchart of another embodiment of a hot surface ignition temperature test method for flammable refrigerants;

[0036] Figure 5 A flowchart for conducting the hot surface ignition temperature test for A2L flammable refrigerants using the provided test method.

[0037] Description of the accompanying drawings:

[0038] 1- surface heating unit, 11- heating platform, 12- heating plate, 13- temperature sensor, 14- isolation tube, 15- temperature adjustment switch, 16- heat insulation layer;

[0039] 2-refrigerant supply unit, 21-refrigerant tank, 22-spray pipe, 221-first pipe section, 222-second pipe section, 23-first valve member, 24-second valve member;

[0040] 3-test controller, 31-display;

[0041] 4-air supply unit, 41-air supply pump, 42-air supply pipe;

[0042] 5-post-processing unit, 51-recovery pump, 52-recovery tank, 53-air recovery pipe, 54-lifting mechanism.

[0043] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0044] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0045] like Figure 1 and Figure 2As shown, an embodiment of a hot surface ignition temperature test device for flammable refrigerants provided by the utility model is provided with a surface heating unit 1, a refrigerant supply unit 2 and a test controller 3.

[0046] The surface heating unit 1 includes a heating platform 11, an isolation tube 14, a temperature regulating switch 15 and a temperature sensor 13. A heating plate 12 is arranged on the upper surface of the heating platform 11. The isolation tube 14 is arranged outside the heating plate 12. The temperature regulating switch 15 is connected to the heating plate 12 by control. The temperature sensor 13 monitors the temperature of the heating plate 12. The refrigerant supply unit 2 includes a refrigerant tank 21, a spray pipe 22, a first valve member 23 and a second valve member 24. The first end of the spray pipe 22 is connected to the refrigerant tank 21, and the second end extends to the top of the heating plate 12. The first valve member 23 is arranged at the connection between the first end of the spray pipe 22 and the refrigerant tank 21, and the second valve member 24 is arranged near the second end of the spray pipe 22. And a test controller 3 is connected to the surface heating unit 1 and the refrigerant supply unit 2 by control.

[0047] Working principle: During the test, the test controller controls the air flow supply unit to establish a stable air flow environment on the surface of the heating table, controls the heating plate to heat to the initial set temperature and maintains it through the temperature adjustment switch, and then sprays the refrigerant to the surface of the heating table in the isolation tube space through the spray pipe, and observes whether the refrigerant ignites within the set temperature to determine the ignition temperature of the refrigerant hot surface.

[0048] The provided hot surface ignition temperature test device for flammable refrigerants can effectively improve the accuracy of hot surface ignition temperature testing, reduce the amount of refrigerant used in a single test, reduce pollution caused by the test, and improve test safety.

[0049] The isolation cylinder 14 is arranged outside the heating plate 12 in the vertical direction, and an air circulation gap is left between the lower end of the isolation cylinder 14 and the upper surface of the heating platform 11, and the second pipe section 222 extends from the center of the isolation cylinder 14 to the vicinity of the heating plate 12. Through the air circulation gap, a smooth flow of air is provided for the combustion process of the flammable refrigerant, thereby providing oxygen required for combustion, avoiding interference from external ambient airflow, and improving the test accuracy.

[0050] Furthermore, the upper surface of the heating platform 11 outside the heating plate 12 is covered with a heat insulation layer 16, the isolation cylinder 14 is vertically arranged above the heat insulation layer 16, and the air circulation gap is provided between the lower end of the isolation cylinder 14 and the heat insulation layer 16. The heat insulation layer 16 can prevent the steam from being ignited by the part other than the top surface of the heating platform 11, prevent the occurrence of high temperature dangerous accidents, and ensure the safety of the test environment.

[0051] Among them, the temperature sensor 13 includes at least one thermocouple, which is fixedly installed on the bottom side of the heating plate 12. The test controller 3 is provided with a display 31 connected to the at least one thermocouple, which can monitor the temperature of the heating plate in real time, ensure the controllability of the surface heating temperature during the test process, and improve the test accuracy.

[0052] In one embodiment, the spray pipe 22 includes a first pipe section 221 arranged between the first valve member 23 and the second valve member 24, and a second pipe section 222 arranged at the rear end of the second valve member 24. The first pipe section 221 is provided with a space for storing liquid refrigerant for a single test, and the end of the second pipe section 222 extends vertically and is spaced apart from the center of the heating plate 12 to improve the safety of the test.

[0053] On the basis of the above embodiment, further, the test controller 3 is controlled and connected with the first valve component 23 and the second valve component 24. The test controller 3 is configured to control the first valve component 23 to transport liquid refrigerant to the first pipe section 221 and then close, and control the second valve component 24 to open when the first valve component 23 is closed to spray refrigerant onto the surface of the heating plate 12.

[0054] In one embodiment, the test device is further provided with an air flow supply unit 4, and the air flow supply unit 4 includes an air supply pipe 42 and an air supply pump 41. The air supply pipe 42 surrounds the bottom of the isolation tube 14 and is connected to the air supply pump 41. The air supply pipe 42 array is provided with an air exhaust port facing the air circulation gap; the test controller 3 is controlled and connected to the air flow supply unit 4, and the test controller 3 is configured to control the air supply pump 41 to provide air flow to the surface of the heating plate 12 through the air circulation gap to establish a stable air flow environment during the test.

[0055] In one embodiment, the test device is further provided with a post-processing unit 5, and the post-processing unit 5 includes an air recovery pipe 53, a recovery pump 51, a recovery tank 52 and a lifting mechanism 54. The recovery tank 52 is connected to the air recovery pipe 53 through the recovery pump 51, and the front end of the air recovery pipe 53 is movably arranged in the isolation cylinder 14, and the lifting mechanism 54 is drivingly connected to the air recovery pipe 53; the test controller 3 is control-connected to the post-processing unit 5, and the test controller 3 is configured to control the lifting mechanism 54 to drive the front end of the air recovery pipe 53 to move up and down and reciprocate in the isolation cylinder 14 after the test is completed, and control the recovery pump 51 to suck the gas in the isolation cylinder 14 to the recovery tank 52 through the air recovery pipe 53.

[0056] like Figure 3 As shown, an embodiment of a hot surface ignition temperature test method for a flammable refrigerant provided by the utility model includes:

[0057] S100. The test controller 3 controls the air supply unit 4 to deliver air to the isolation channel through the air flow gap according to the set air flow rate, and establishes a stable air flow environment on the upper surface of the heating table 11;

[0058] S200. The heating plate is heated to the initial set temperature and maintained by the temperature adjustment switch 15;

[0059] S300. Control the first valve member 23 to open and deliver liquid refrigerant for a single test to the first pipe section 221 of the spray pipe 22, and then close it, and then open the second valve member 24 to spray the refrigerant on the surface of the heating platform 11 in the space of the isolation cylinder 14;

[0060] S400. Observe whether the refrigerant ignites within the set temperature;

[0061] S500. If ignition does not occur, the refrigerant in the isolation cylinder 14 is removed by the post-processing unit 5; then, the temperature is increased by a set amplitude based on the initial set temperature, and S200-S400 is repeated;

[0062] S600. If ignition occurs, the temperature of the heating plate is reduced by a set amplitude and maintained. If no ignition occurs after repeating S200-S500 for a set number of times, the temperature before reduction is determined to be the hot surface ignition temperature.

[0063] like Figure 4 As shown, in another embodiment, the embodiment of the hot surface ignition temperature test method for flammable refrigerants provided further includes:

[0064] S700. The test controller 3 controls the air supply unit 4 to change the air flow rate between the isolation cylinder 14 and the upper surface of the heating table 11, thereby changing the air flow environment;

[0065] S800. Repeat S200-S600 to test the hot surface ignition temperature after changing the air flow environment.

[0066] Provided is a hot surface ignition temperature test device and test method for flammable refrigerant. A test control unit is connected to a surface heating unit and a refrigerant supply unit. The test temperature is monitored in real time by a temperature sensor, and the temperature of a heating plate is controlled by a temperature regulating switch. The supply of flammable refrigerant is controlled by a first valve member and a second valve member. The first valve member is controlled to deliver liquid refrigerant to the first pipe section and then closed, and the second valve member is controlled to open when the first valve member is closed to spray refrigerant onto the surface of the heating plate, thereby avoiding the control of the first valve member and the second valve member being opened at the same time. A stable air flow environment is constructed in the isolation tube cover, and the heating plate creates a hot surface environment with precise temperature. The use of a small dose of refrigerant for a single test is accurately controlled, thereby improving the safety of the test process.

[0067] The provided hot surface ignition temperature test device and test method for flammable refrigerants are suitable for repeated tests, are easy to operate, and reduce the influence of the external environment. The flammable refrigerant is accurately sprayed above the heating plate in the isolation tube, and the hot surface ignition temperature is tested in the above-mentioned air flow environment and hot surface environment in the isolation tube cover, thereby improving the accuracy of the hot surface ignition temperature and preventing the external diffusion of flammable refrigerants during the test to cause environmental pollution. The process is safe and controllable, and the test results are accurate, which can meet the test needs of testing the hot surface ignition temperature of flammable refrigerants in factories.

[0068] The hot surface ignition temperature test device and test method for flammable refrigerants provided by the utility model are described in detail below in conjunction with specific embodiments to better understand the technical solution of the utility model.

[0069] like Figure 1 and Figure 2 As shown, a hot surface ignition temperature test device for flammable refrigerants provided by the utility model is provided with a surface heating unit 1 and a refrigerant supply unit 2, including a refrigerant tank 21, a first valve member 23, a second valve member 24, a spray pipe, an isolation tube 14, a heating platform 11, a thermocouple, an insulation heating platform 11, a display 31, a temperature adjustment switch 15 and a test controller 3.

[0070] The first pipe section 221 of the spray pipe 22 is located between the first valve member 23 and the second valve member 24, and the second pipe section 222 of the spray pipe 22 is located behind the second pipe section 222. The first valve member 23 arranged at the tank mouth of the refrigerant tank 21 is used to allow the refrigerant to enter the spray pipe in liquid form, and the first pipe section 221 is used to adjust and control the storage amount of the refrigerant for a single measurement, retaining a liquid volume of 1.0cm3±0.2cm3 of the refrigerant to be tested.

[0071] The second pipe section 222 of the spray pipe 22 has a length of 250 mm ± 5.0 mm, an outer diameter of less than or equal to 4 mm, and an inner diameter of 1.6 mm ± 0.1 mm; the end of the second pipe section 222 extends 40 mm ± 10 mm above the heating platform 11, and the pipeline points vertically to the center of the heating platform 11.

[0072] In a specific implementation, a borosilicate or quartz isolation tube 14 is used as the isolation tube 14 , and the isolation tube 14 is set to be 230 mm±10 mm in length and 70 mm±10 mm in inner diameter.

[0073] The bottom of the isolation cylinder 14 is placed at the center of the upper surface of the heating table 11 and supported so that it is installed vertically and there is a 2.5mm±0.2mm air circulation gap between its bottom edge and the insulating top. The test device on the top of the isolation cylinder 14 should be located in the laminar flow area of ​​the test room ventilation so that the airflow in the isolation cylinder 14 will not be disturbed. During the test, a constant air flow rate is established between the isolation cylinder 14 and the heating table 11. The air flow dilutes the vapor to form an optimal concentration (approximate equivalent) for ignition on the hot surface;

[0074] The heating platform 11 includes a heating plate 12, a thermocouple and a temperature adjustment switch 15 located on the upper surface of the heating platform 11. The temperature adjustment switch 15 is used to set the heating temperature, and the temperature can be set in an amplitude of 5°C or 10°C; the display 31 can display the heating temperature set by the temperature adjustment switch 15, and is used to monitor the real-time temperature of the heating platform 11.

[0075] The heating plate 12 located at the center of the upper surface of the main body of the heating table 11 is composed of a stainless steel flat plate with a diameter of 50mm±2.0mm and a thickness of 6mm±2.0mm. Its surface texture complies with ISO 1302 regulations to form a hot surface that can be evenly heated.

[0076] In a specific implementation, the temperature sensor 13 is a thermocouple, which is a K-type thermocouple with an independent wire spot-welded on the back side of the center of the upper surface of the heating platform 11; the insulation board can withstand a high temperature of at least 815°C and is insulated from the heating plate 12, and the insulation layer 16 can prevent the steam from being ignited by parts other than the top surface of the heating platform 11, thereby preventing high-temperature dangerous accidents and ensuring the safety of the test environment.

[0077] The test controller 3 is connected to the first valve member 23 , the second valve member 24 , the thermocouple and the temperature regulating switch 15 .

[0078] like Figure 5 As shown, taking A2L as an example, the hot surface ignition temperature test method for flammable refrigerants is implemented as follows:

[0079] S100a. Place the entire device in the test room. According to the standard, the test environment conditions should be set at 23℃±3℃ and 50%RH±5%RH. During the test, a constant air flow rate is established between the isolation tube 14 and the heating table 11. Ensure that the positions of the devices are fixed to ensure a safe and reliable test environment.

[0080] S200a. The heating table 11 is placed on a stable desktop, the temperature is initially set to 800 ℃, heated to a stable test temperature for 5min;

[0081] S300a. The refrigerant used for the test shall be in accordance with the standard composition (NC) specified in ISO 817. The liquid refrigerant shall be cut off between the first valve 23 and the second valve 24. Open the valve to spray the liquid refrigerant on the center of the heating table 11;

[0082] S400a observe and record the release of liquid refrigerant after the isolation tube 14: whether there is ignition (flame) in the tube within 3min;

[0083] S500a. If no ignition occurs, ventilation for at least 5 minutes is required to remove external reaction products and residual refrigerant. Raise the temperature by 20°C and repeat steps 3 and 4;

[0084] S600a. If ignition occurs, the temperature is reduced in steps of 20°C until no ignition occurs after 5 repeated tests. This temperature is recorded as the hot surface ignition temperature (HSIT).

[0085] The utility model realizes the measurement of the safety evaluation of the hot surface ignition temperature of the A2L refrigerant for the first time. It has a simple and intuitive structure, convenient and reliable operation, and can test the hot surface ignition temperature of a variety of flammable refrigerants to ensure the safety requirements of the flammable refrigerants.

[0086] It should be particularly noted that the device structure involved in the present utility model is a new type of testing system, and the device itself does not carry out any innovation relying on algorithms or circuit connections.

[0087] Compared with the prior art, the utility model of the hot surface ignition temperature test device and test method for flammable refrigerants customizes a precise and compact heating surface according to the size of the refrigerant liquid dripping onto the smooth surface during the test, which greatly reduces the consumption of heating elements and improves the test efficiency and test accuracy. All surfaces on the heating plane except the test surface are insulated with ceramic fiberboard that can withstand 815°C. The insulation layer 16 ensures that the steam will not be ignited by the part other than the top surface of the heating table 11, and the fully transparent test process can directly observe the instantaneous changes of the refrigerant when it contacts the high-temperature hot surface. At the same time, since the device has a wide temperature range and covers the hot surface ignition temperature of a variety of refrigerants, the device can also test other related types of refrigerants. By independently setting the temperature of the hot surface, the highest temperature at which the refrigerant cannot ignite can be truly and effectively detected.

[0088] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A hot surface ignition temperature test device for flammable refrigerants, characterized in that: include: A surface heating unit (1) comprises a heating platform (11), an isolation tube (14), a temperature regulating switch (15) and a temperature sensor (13); a heating plate (12) is arranged on the upper surface of the heating platform (11); the isolation tube (14) is arranged outside the heating plate (12); the temperature regulating switch (15) is controllably connected to the heating plate (12); and the temperature sensor (13) monitors the temperature of the heating plate (12); A refrigerant supply unit (2), comprising a refrigerant tank (21), a spray pipe (22), a first valve component (23) and a second valve component (24); the first end of the spray pipe (22) is connected to the refrigerant tank (21), and the second end extends to above the heating plate (12); the first valve component (23) is arranged at the connection between the first end of the spray pipe (22) and the refrigerant tank (21), and the second valve component (24) is arranged near the second end of the spray pipe (22); the spray pipe (22) comprises a first pipe section (221) arranged between the first valve component (23) and the second valve component (24), and a second pipe section (222) arranged at the rear end of the second valve component (24); A test controller (3) is control-connected to the surface heating unit (1) and the refrigerant supply unit (2); the test controller (3) is control-connected to the first valve component (23) and the second valve component (24), and the test controller (3) is configured to control the first valve component (23) to close after conveying liquid refrigerant to the first pipe joint (221), and to control the second valve component (24) to open when the first valve component (23) is closed to spray refrigerant onto the surface of the heating plate (12); the temperature sensor (13) comprises at least one thermocouple, and the at least one thermocouple is fixedly mounted on the bottom side of the heating plate (12); the test controller (3) is provided with a display (31) connected to the at least one thermocouple.

2. The hot surface ignition temperature test device for flammable refrigerants according to claim 1, characterized in that: The first pipe section (221) is provided with a space for storing liquid refrigerant for a single test, and the end of the second pipe section (222) extends vertically and is arranged at a distance from the center of the heating plate (12).

3. The hot surface ignition temperature test device for flammable refrigerants according to claim 2, characterized in that: The isolation tube (14) is arranged vertically outside the heating plate (12), and an air circulation gap is left between the lower end of the isolation tube (14) and the upper surface of the heating platform (11). The second pipe section (222) extends from the center of the isolation tube (14) to the vicinity of the heating plate (12).

4. The hot surface ignition temperature test device for flammable refrigerants according to claim 3, characterized in that: The upper surface of the heating platform (11) outside the heating plate (12) is covered with a heat insulation layer (16), the isolation tube (14) is vertically arranged above the heat insulation layer (16), and the air circulation gap is provided between the lower end of the isolation tube (14) and the heat insulation layer (16).

5. The hot surface ignition temperature test device for flammable refrigerants according to claim 3, characterized in that: The test device is also provided with an air flow supply unit (4), the air flow supply unit (4) comprising an air supply pipe (42) and an air supply pump (41), the air supply pipe (42) surrounds the vicinity of the bottom of the isolation cylinder (14) and is connected to the air supply pump (41), and the air supply pipe (42) array is provided with an air discharge port facing the air circulation gap; The test controller (3) is connected to the air flow supply unit (4) for control. The test controller (3) is configured to control the air supply pump (41) to provide air flow to the surface of the heating plate (12) through the air circulation gap, so as to establish a stable air flow environment during the test.

6. The hot surface ignition temperature test device for flammable refrigerants according to claim 1 or 5, characterized in that: The testing device is further provided with a post-processing unit (5), the post-processing unit (5) comprising an air recovery pipe (53), a recovery pump (51), a recovery tank (52) and a lifting mechanism (54), the recovery tank (52) being connected to the air recovery pipe (53) via the recovery pump (51), the front end of the air recovery pipe (53) being movably arranged in the isolation cylinder (14), and the lifting mechanism (54) being drivingly connected to the air recovery pipe (53); The test controller (3) is connected to the post-processing unit (5) and is configured to control the lifting mechanism (54) to drive the front end of the air recovery pipe (53) to move up and down and reciprocate in the isolation cylinder (14) after the test is completed, and to control the recovery pump (51) to suck the gas in the isolation cylinder (14) to the recovery tank (52) through the air recovery pipe (53).

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