A method for controlling the type of ice accretion in ice accretion tests

Abstract

A method for controlling the type of ice accretion in ice accretion tests, which relates to the technical field of ice accretion. It solves the problem of accurately simulating the ice accretion test of large test pieces. The method includes: setting the humidity in the test chamber, turning on the defogger, running the circulation fan, and introducing low-humidity air; setting the temperature in the test chamber, turning on the cooling equipment, running the circulation fan, and introducing low-temperature air; when the temperature reaches the set value, setting the background fan frequency, turning on the background fan, and providing spray background wind; setting the air supply pressure, turning on the main air supply and secondary air supply, and the compressed air is ejected through the nozzle; setting the water supply pressure, turning on the main water supply and secondary water supply, transporting low-temperature ultrapure water, and starting spraying; after the test ends, closing the water supply pressure, closing the waterway valve, closing the air supply pressure, closing the air path valve, and stopping spraying; maintaining the set temperature and strengthening the ice layer on the surface of the test piece; after the ice accretion test ends, turning off the electrical equipment. It is used to evaluate the ice accretion performance of large test pieces in cold environments.

Description

Technical Field

[0001] The present invention relates to the technical field of icing, and particularly to a method for controlling icing types in icing tests. Background Art

[0002] Icing is a complex phase change heat transfer process with numerous influencing parameters, mainly including environmental temperature and humidity, air flow velocity and direction, liquid water content in the cloud and fog environment, particle size distribution of supercooled droplets, etc. Icing can be classified into three categories: frost accumulation, sedimentation ice, and cloud and fog ice. Among them, cloud and fog ice includes clear ice, frost ice, and mixed ice: different ice types are likely to form under different cloud and fog parameters and low-temperature environmental temperatures. When conducting icing tests, in order to ensure the repeatability of test results, it is necessary to precisely control the main influencing factors that affect the test results.

[0003] The existing patent CN210953884U discloses a spray icing test system based on the Bernoulli effect in a low-temperature environment, specifically including a low-temperature test chamber with a test piece placed inside, an atomizing spray device arranged in the low-temperature test chamber for uniformly spraying the test piece, a pneumatic control device connected to the atomizing spray device for controlling the pressure of the spray, and a water supply device connected to the atomizing spray device for supplying low-temperature water; the temperature inside the low-temperature test chamber is below 0°C, and the temperature of the low-temperature water is close to 0°C; the atomizing spray device includes a nozzle rack and a plurality of atomizing nozzles connected to the nozzle rack, the test piece is fixed inside the nozzle rack, and the plurality of atomizing nozzles are evenly distributed around the test piece and equidistant from the center of the test piece.

[0004] Although the patent CN210953884U provides a spray icing test system, its design is mainly limited to the application of small test pieces. The scale of this system is relatively small and cannot meet the requirements of icing tests on the surfaces of large test pieces. In practical applications, due to their size and weight, large test pieces require a larger test space to ensure the accuracy and reliability of the test. Therefore, the existing spray icing test systems cannot be directly applied to the icing tests of large test pieces. The design parameters and control strategies of small-sized spray icing test systems are usually optimized to adapt to small test pieces. If a large test piece is placed in this system, the stability of the test conditions may be affected. For example, the adjustment of wind speed, humidity, and temperature may not be evenly distributed over the entire surface of the test piece, resulting in uneven icing effects or failure to achieve the expected test results.

[0005] Moreover, due to the numerous parameters affecting the icing effect, these parameters must be precisely controlled during the icing test. For example, the temperature and humidity in the icing test space have a direct impact on the icing speed and ice layer quality. The air flow speed and direction determine the air flow distribution on the surface of the test piece, thus affecting the uniformity and morphology of the ice layer. The liquid water content and the size distribution of supercooled droplets in the cloud and fog environment are directly related to the icing rate and degree on the surface of the test piece. These factors are interrelated and interact with each other, making the icing test complex and precise.

[0006] To accurately simulate these complex parameters and ensure the reliability of the test results, a more advanced and flexible method for controlling the icing type in the icing test is required. It can simulate various climate and meteorological conditions in the real environment and precisely control various parameters affecting the icing effect. Summary of the Invention

[0007] Aiming at the problem of accurately simulating the icing test of large test pieces, the present invention proposes a method for controlling the icing type in the icing test, and the method includes:

[0008] S1: Set the air humidity in the test chamber, turn on the defogger for dehumidification, start the circulation fan, and introduce low-humidity air outside the test chamber.

[0009] S2: Set the air temperature in the test chamber, turn on the cooling, start the circulation fan, and introduce low-temperature air outside the test chamber.

[0010] S3: After the temperature in the test chamber reaches the set temperature, set the operating frequency of the background fan according to the test requirements, turn on the background fan, and provide the background air required by the spray nozzle.

[0011] S4: Set the air supply pressure, turn on the main air supply and secondary air supply pipelines, and the compressed air generated by the air compressor is ejected through the nozzle.

[0012] S5: After 10 seconds, set the nozzle water supply pressure, turn on the main water supply and secondary water supply pipelines, and the low-temperature ultrapure water transported by the water pump is ejected through the nozzle to start spraying.

[0013] S6: After the test is over, set the water supply pressure to 0 bar, close the waterway valve, and after 10 seconds, set the air supply pressure to 0 bar, close the air circuit valve, and the spraying stops.

[0014] S7: Keep the set temperature unchanged for 30 minutes to strengthen the ice layer on the surface of the test piece.

[0015] S8: After the icing test is over, turn off the electrical equipment.

[0016] Furthermore, a preferred method is also proposed. The air supply pressure is monitored by a pressure transmitter, and the monitored value is fed back to the PLC industrial control computer. After PID calculation, the opening value of the electric control valve is output.

[0017] Furthermore, a preferred method is also proposed. The spray nozzles are selected according to a continuously adjustable side spray rate of 5 - 50 mm / h and a spray particle size of 10 - 50 μm.

[0018] Furthermore, a preferred method is also proposed. The test chamber includes: an induced draft fan, a background fan, a duct, a honeycomb panel, a spray rack, an exhaust fan, and a test piece; the test piece is placed in the internal space of the test chamber, and in front of it, there are successively installed a spray rack, a duct, a honeycomb panel, a duct, and a background fan. An induced draft fan is installed at the front of the test chamber, and an exhaust fan is installed at the rear. A demister is installed behind the test piece; the induced draft fan and the exhaust fan form a circulating fan.

[0019] Furthermore, a preferred method is also proposed. The circulating fan is controlled by a frequency converter. Multiple temperature sensors are used to measure the temperature values at different positions of the test piece respectively, and the average value is calculated. This average value is used as the temperature inside the test chamber; when the temperature inside the test chamber is higher than the set temperature +1°C, the circulating fan runs at full frequency of 50 Hz; when the temperature inside the test chamber is lower than the set temperature -1°C, the circulating fan runs at a frequency of 30 Hz; when the icing test stops, the fan stops running.

[0020] Furthermore, a preferred method is also proposed. The temperature sensors are four temperature sensors, which measure the temperature values at four positions: the front left, the rear left, the front right, and the rear right of the test piece respectively.

[0021] Furthermore, a preferred method is also proposed. The air supply pipeline uses a stainless steel hose.

[0022] Furthermore, a preferred method is also proposed. The main air supply pipeline is arranged between the air compression system and the spray rack, and is used to transport all the compressed air required for the array nozzles to spray. Seven secondary air supply pipelines are arranged on each layer of the spray rack, and are used to transport the compressed air required for the nozzles in one layer of the spray rack to spray; the main water supply pipeline is arranged between the pre-cooling water system and the spray rack, and is used to transport all the low-temperature ultrapure water required for the array nozzles to spray. Seven secondary water supply pipelines are arranged on each layer of the spray rack, and are used to transport the low-temperature ultrapure water required for the nozzles in one layer of the spray rack to spray.

[0023] Furthermore, a preferred method is also proposed. The air supply flow rate of the main air supply pipeline is 0.7 - 2.2 Nm , ,

[0022] , 3 ,

[0021] ,

[0024] ,

[0023] , / min, and the inner diameter of the main air supply pipeline is 40 mm. ​Furthermore, a preferred method is also proposed, where the water supply flow rate of the main water supply pipeline is 75.6 - 820 L / h, and the inner diameter of the main water supply pipeline is 40 mm.

[0025] The advantages of the present invention are as follows:

[0026] The present invention solves the problem of accurately simulating the icing test of large test pieces.

[0027] Icing tests are usually used to simulate the operation of large structures or equipment in cold environments. A method for controlling the icing type in icing tests proposed by the present invention can be applied to large test pieces because it can accurately control parameters such as humidity, temperature, and wind speed in the test chamber to meet the specific icing test requirements of large test pieces. By setting the humidity, temperature, and background wind control in the test chamber, the method of the present invention can more accurately simulate the climatic conditions in the real environment. Large test pieces often need to be subjected to icing tests under different humidity and temperature conditions to evaluate their cold resistance performance under various environmental conditions. The method of the present invention can provide more realistic icing conditions for large test pieces, improving the reliability and accuracy of test results.

[0028] In terms of spray control, a method for controlling the icing type in icing tests proposed by the present invention can precisely adjust the spray process by setting the air supply and water supply pressures and controlling the air jet and water spray amounts of the nozzles. Large test pieces usually need to be subjected to icing tests under different ice fog densities and particle sizes to evaluate their frost resistance performance against ice fog. The method of the present invention ensures the accuracy and controllability of the spray operation, making the test results more reliable.

[0029] For large test pieces, the formation and stability of the surface ice layer are very important for the accuracy of the icing test. After the test, the method of the present invention can better simulate the formation and stability of the ice layer under actual environmental conditions through a reinforcement operation of maintaining the set temperature for 30 minutes. This can provide more reliable data for evaluating the icing performance of large test pieces in cold environments. Brief Description of the Drawings

[0030] Figure 1 It is a flowchart of a method for controlling the icing type in icing tests described in Embodiment 1;

[0031] Figure 2 It is a PID schematic diagram described in Embodiment 2;

[0032] Figure 3 It is a schematic diagram of an icing test described in Embodiment 4. Detailed Embodiments

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

[0034] Embodiment 1. Refer to Figure 1 This embodiment will be described. A method for controlling the icing type in an icing test described in this embodiment includes:

[0035] S1: Set the air humidity in the test chamber, turn on the dehumidifier for dehumidification, start the circulation fan, and introduce low-humidity air outside the test chamber to take away the high-humidity air in the test chamber;

[0036] S2: Set the air temperature in the test chamber, turn on the cooling, start the circulation fan, and introduce low-temperature air outside the test chamber to take away the normal-temperature air in the test chamber;

[0037] S3: After the temperature in the test chamber reaches the set temperature, set the operating frequency of the background fan according to the test requirements, turn on the background fan, and provide the background wind required by the spray nozzle;

[0038] S4: Set the air supply pressure, turn on the main air supply and secondary air supply pipelines, and the compressed air generated by the air compressor is ejected through the nozzle;

[0039] S5: After 10 seconds, set the nozzle water supply pressure, turn on the main water supply and secondary water supply pipelines, and the low-temperature ultrapure water conveyed by the water pump is ejected through the nozzle to start spraying;

[0040] S6: After the test is completed, set the water supply pressure to 0 bar, close the waterway valve, and after 10 seconds, set the air supply pressure to 0 bar and close the air path valve to stop spraying;

[0041] S7: Keep the set temperature unchanged for 30 minutes to strengthen the ice layer on the surface of the test piece;

[0042] S8: After the icing test is completed, turn off the electrical equipment.

[0043] A method for controlling the icing type in the icing test designed in this embodiment can accurately control the climate conditions in the test chamber by setting the humidity and temperature in the test chamber and using a defogger and a cooling device in steps S1 and S2. In this way, the icing conditions under different humidity and temperature conditions in the real environment can be simulated, and flexible adjustment can be made according to the test requirements. In step S3, the operating frequency of the background fan is set according to the test requirements, and the background fan is turned on to provide the background wind required by the nozzle. This can better simulate the wind speed conditions in the actual environment and is of great significance for the accuracy and reliability of the test results. By setting the gas supply and water supply pressures, opening the corresponding gas path and water path, and controlling the gas jet and water spray amounts of the nozzle in steps S4 and S5, the spraying operation is realized. In this way, the spraying process in the icing test can be accurately controlled, and the formation of actual ice fog can be simulated. In step S6, the water supply pressure is set to 0 bar, where 0 bar represents the water supply gauge pressure. After 10 seconds, the gas supply pressure is set to 0 bar, where 0 bar represents the gas supply gauge pressure. In step S7, the set temperature is kept unchanged and continued for 30 minutes to strengthen the surface ice layer of the test piece. This can better simulate the formation and stability of the ice layer in the actual environment and provide reliable data for the evaluation of the icing performance of the test. Each step in this method can be realized by an automated control system, which improves the convenience and stability of the test operation. The automated control system can accurately control the parameter setting and operating state of each step, improving the accuracy and consistency of the test.

[0044] Icing tests are usually used to simulate the operation of large structures or equipment in cold environments. The method provided in this embodiment can be applied to large test pieces because it can accurately control parameters such as humidity, temperature, and wind speed in the test chamber to meet the specific icing test requirements of large test pieces. By setting the humidity, temperature, and background wind control in the test chamber, the method provided in this embodiment can more accurately simulate the climate conditions in the real environment. Large test pieces often need to be subjected to icing tests under different humidity and temperature conditions to evaluate their cold resistance performance under various environmental conditions. The method of this embodiment can provide more real icing conditions for large test pieces, improving the reliability and accuracy of the test results. In terms of spray control, the method of this embodiment can accurately adjust the spraying process by setting the gas supply and water supply pressures and controlling the gas jet and water spray amounts of the nozzle. Large test pieces usually need to be subjected to icing tests under different ice fog densities and particle sizes to evaluate their anti-freezing performance against ice fog. The method of this embodiment ensures the accuracy and controllability of the spraying operation, making the test results more reliable.

[0045] For large test specimens, the formation and stability of surface ice layers are crucial for the accuracy of icing tests. After the test, the method of this embodiment can better simulate the formation and stability of ice layers under actual conditions through a reinforcement operation of maintaining a set temperature for 30 minutes. This can provide more reliable data for evaluating the icing performance of large test specimens in cold environments.

[0046] Embodiment 2. Refer to Figure 2 Describe this embodiment. This embodiment further defines a method for controlling icing types in icing tests described in Embodiment 1. The supply air pressure is monitored by a pressure transmitter, and the monitored value is fed back to the PLC industrial control computer. After PID calculation, the opening value of the electric control valve is output.

[0047] Specifically, in this embodiment, a pressure transmitter is first installed to monitor the gas pressure in the air supply pipeline. A pressure transmitter is a sensor that can convert gas pressure into an electrical signal. The gas pressure value measured by the pressure sensor is transmitted to the PLC (Programmable Logic Controller) industrial control computer. A PLC is a computer device used for industrial automation control, with fast processing and logic control capabilities.

[0048] In the PLC industrial control computer, through the PID (Proportional, Integral, Derivative) control algorithm, the gas pressure value measured by the sensor is calculated and analyzed. The PID algorithm can automatically adjust the output signal according to the difference between the current pressure value and the set value. After PID calculation, the PLC industrial control computer outputs an opening value of an electric control valve, and this valve is used to control the gas flow. The electric control valve can automatically adjust the opening size according to the PLC instruction to change the gas flow and pressure.

[0049] The corresponding needle-type electric control valve is adjusted according to the opening value output by the PLC industrial control computer to control the supply air pressure. By changing the opening of the electric control valve, the channel area of the valve can be adjusted, thereby changing the gas flow rate and pressure. By continuously monitoring the gas pressure, calculating and controlling the opening value, and using the electric control valve to adjust the supply air pressure in real time, it is ensured that the pressure during the test always remains within the set value range.

[0050] This process can achieve precise control of the supply air pressure to meet the requirements of icing tests. In the icing test of large test specimens, the control of the supply air pressure is very important for generating specific types of ice layers. This embodiment uses a pressure transmitter to monitor the supply air pressure and feeds the monitored value back to the PLC industrial control computer. After PID calculation, the opening value of the electric control valve can be accurately output, thereby precisely controlling the supply air pressure. By using this control method, the stability and consistency of the test conditions can be ensured, and reproducible experimental results can be obtained.

[0051] Embodiment 3. This embodiment is a further limitation of a method for controlling the icing type in the icing test described in Embodiment 1. The spray nozzle is selected according to a continuously adjustable side spray rate of 5 - 50 mm / h and a spray particle size of 10 - 50 μm.

[0052] In the icing test of large test pieces, the spray rate is very important for forming a suitable ice layer. The spray nozzle in this embodiment provides a continuously adjustable side spray rate ranging from 5 - 50 mm / h. This means that the test personnel can accurately select an appropriate spray rate according to the test requirements and the characteristics of the large test piece and the target ice layer thickness. By adjusting the spray rate, the predictive growth and control of the ice layer can be achieved, ensuring the accuracy and repeatability of the test.

[0053] In the icing test, the spray particle size is one of the important factors affecting the formation and characteristics of the ice layer. The spray nozzle in this embodiment provides a spray particle size selection range of 10 - 50 μm. By carefully selecting an appropriate spray particle size, the roughness and morphology of the ice layer surface, as well as the structure and performance of the ice layer, can be adjusted according to the test requirements. This fine selection of spray particle size can meet the specific requirements of large test pieces and make the test results more accurate and reliable.

[0054] From the perspective of the icing test applicable to large test pieces, the further limitation in this embodiment has significant progress in both the rate adjustment and spray particle size selection of the spray nozzle. These improvements enhance the flexibility, accuracy, and controllability of the test, enabling the icing test of large test pieces to better meet specific research and evaluation needs and produce accurate and repeatable test results. Different nozzles have different spray characteristics, and the spray characteristics include spray particle size, spray volume, spray cone angle, spray distance, etc. In this embodiment, the BMIJ 7004 type air atomizing nozzle produced by Ichinomiya Co., Ltd. of Nippon Mist is selected.

[0055] Embodiment 4. Refer to Figure 3 This embodiment is described. This embodiment is a further limitation of a method for controlling the icing type in the icing test described in Embodiment 1. The test chamber includes: an induced draft fan, a background fan, a wind duct, a honeycomb panel, a spray rack, an exhaust fan, and a test piece; the test piece is placed in the internal space of the test chamber, and a spray rack, a wind duct, a honeycomb panel, a wind duct, and a background fan are sequentially installed in front of it. The induced draft fan is installed at the front of the test chamber, and the exhaust fan is installed at the rear. A demister is installed behind the test piece; the induced draft fan and the exhaust fan form a circulating fan.

[0056] In this embodiment, the design of the test chamber takes into account the placement and operation requirements of large test pieces. The test pieces can be placed in the internal space of the test chamber, which provides sufficient space to accommodate and place large test pieces. By a reasonable installation sequence and configuration (spray rack, air duct, honeycomb panel, air duct and background fan), it is possible to ensure an appropriate space between the test piece and other test equipment and guarantee that the test piece obtains the required icing conditions.

[0057] In this embodiment, the configuration of equipment such as induced draft fans, background fans, exhaust fans, etc. can achieve the control and recycling of the air flow. The induced draft fan and the exhaust fan form a circulating fan system. The induced draft fan is installed at the front of the test chamber, and the exhaust fan is installed at the rear. Through the circulating fan system, the wind speed and wind direction can be controlled to make the air flow distribution in the icing test uniform and controllable, ensuring the repeatability and accuracy of the test.

[0058] In this embodiment, the dehumidifier is installed at the rear of the test piece, which can achieve humidity control and dehumidification treatment in the test environment. This is crucial for controlling the humidity conditions in the icing test. Especially in long-term tests, maintaining a stable and constant humidity in the test environment can improve the accuracy and reliability of the test results.

[0059] Embodiment 5: This embodiment further defines a method for controlling the icing type in the icing test described in Embodiment 1. The circulating fan is controlled by a frequency converter. Multiple temperature sensors are used to measure the temperature values at different positions of the test piece, and the average value is calculated and used as the temperature inside the test chamber. When the temperature inside the test chamber is higher than the set temperature +1°C, the circulating fan operates at the full frequency of 50 Hz. When the temperature inside the test chamber is lower than the set temperature -1°C, the circulating fan operates at a frequency of 30 Hz. When the icing test stops, the fan stops running.

[0060] In this embodiment, multiple temperature sensors are used to measure the temperature values at different positions of the test piece, and the average value is used as the temperature inside the test chamber. In this way, the temperature inside the test chamber can be monitored more accurately, and the operating frequency of the circulating fan can be adjusted in real time. In this embodiment, a frequency converter is used to control the operating frequency of the circulating fan. When the temperature inside the test chamber is higher than the set temperature +1°C, the circulating fan operates at the full frequency of 50 Hz to provide sufficient cooling effect. When the temperature inside the test chamber is lower than the set temperature -1°C, the circulating fan operates at a frequency of 30 Hz to avoid excessive cooling. This precise temperature control can maintain the stability of the test environment and ensure the accuracy of the test results. By adjusting the operating frequency of the circulating fan according to the change of the temperature inside the test chamber, this embodiment can achieve the optimization of energy consumption. When the temperature inside the test chamber is lower than the set temperature -1°C, reducing the fan operating frequency can reduce energy consumption and improve energy utilization efficiency.

[0061] Embodiment 6. This embodiment further limits a method for controlling the icing type in the icing test described in Embodiment 5. The temperature sensors are four temperature sensors, which respectively measure the temperature values at four positions: the front left, the rear left, the front right, and the rear right of the test piece.

[0062] Compared with Embodiment 5, in this embodiment, four temperature sensors are used to measure the temperature values at four positions: the front left, the rear left, the front right, and the rear right of the test piece. This can more comprehensively understand the temperature distribution at different positions of the test piece, thereby more accurately controlling the icing type. Especially for large test pieces, there may be significant temperature differences in the test chamber. Using multiple sensors can better cover the entire test piece, ensuring the accuracy and stability of the test process.

[0063] By using the temperature sensors at four positions, the temperature of the test piece can be measured in real time at different positions, and the overall temperature situation can be obtained through comprehensive calculation. This will help to more accurately judge the temperature condition of the test piece and be able to more finely adjust the icing method to meet the requirements of the test. For example, if the temperature at a certain position is relatively high, the icing at that position can be strengthened to achieve a uniform temperature distribution.

[0064] By monitoring and controlling the temperature at different positions of the test piece, this embodiment can better maintain the stability and uniformity of the test environment. This will help to improve the test efficiency and accuracy, ensuring the reliability of the test results. In the icing test, accurate temperature control is very crucial, especially for large test pieces. Due to their large volume and slow radiation heat dissipation, using four-position temperature sensors for control makes the icing type more accurate and effective.

[0065] Embodiment 7. This embodiment further limits a method for controlling the icing type in the icing test described in Embodiment 1. The air supply pipeline uses a stainless steel hose.

[0066] In the icing test, compressed air usually needs to be introduced into the test chamber for spraying, and the stainless steel hose can effectively withstand high pressure, ensuring the reliability of the air supply pipeline.

[0067] Embodiment 8. This embodiment further defines a method for controlling ice-covering types in ice-covering tests described in Embodiment 5. The air supply pipeline includes a main air supply pipeline and a secondary air supply pipeline. The main air supply pipeline is arranged between the air compression system and the spray rack, and is used to transport all the compressed air required for the array nozzles to spray. Seven secondary air supply pipelines are arranged on each layer of the spray rack and are used to transport the compressed air required for the nozzles in one layer of the spray rack to spray. The main water supply pipeline is arranged between the pre-cooled water system and the spray rack and is used to transport all the low-temperature ultrapure water required for the array nozzles to spray. Seven secondary water supply pipelines are arranged on each layer of the spray rack and are used to transport the low-temperature ultrapure water required for the nozzles in one layer of the spray rack to spray.

[0068] In the spray rack, each of the main water supply and air supply pipelines is divided into seven secondary branches, corresponding to each layer of the spray rack one by one, so as to transport the compressed air and low-temperature ultrapure water required for the nozzles in each layer to spray, which is convenient for maintenance and repair. And a main air (water) supply pipeline is selected for the connection between the spray rack and the air compression system and the pre-cooled water system, which simplifies the connection between each subsystem on the premise of meeting the required water supply and air supply.

[0069] Embodiment 9. This embodiment further defines a method for controlling ice-covering types in ice-covering tests described in Embodiment 1. The air supply flow rate of the main air supply pipeline is 0.7 - 2.2 Nm 3 / min, and the inner diameter of the main air supply pipeline is 40 mm.

[0070] The air supply pipeline described in this embodiment can provide an air supply flow rate of 13 - 45 NL / min. Large test pieces usually require a larger air supply flow rate to ensure full coverage and effect during the ice-covering process. By expanding the air supply flow rate range, this embodiment can meet the requirements of large test pieces for higher air supply demand and provide better test effects. The specification of the air supply pipeline is a 4-inch British standard stainless steel pipe, which is selected based on considering the size of large test pieces. Large test pieces usually have a larger surface area, so a larger air supply channel is required to ensure the uniformity of air supply and the consistency of ice-covering effects. By using a 4-inch pipe specification, this embodiment can ensure the stability and uniformity of air supply and provide sufficient ice coverage for large test pieces.

[0071] Embodiment 10. This embodiment further defines a method for controlling ice-covering types in ice-covering tests described in Embodiment 5. The water supply flow rate of the main water supply pipeline is 75.6 - 820 L / h, and the inner diameter of the main water supply pipeline is 40 mm.

[0072] The range of the water supply flow rate is determined by multiplying the water flow rate range of a single nozzle by 42, which can ensure the water flow rate required for the array nozzles to spray. The selection of the inner diameter of the main water supply pipeline is based on multiplying the inner diameter of the nozzle water supply, which is 6 mm, by Determined to be approximately 38.8 mm and set as 40 mm to ensure there is sufficient margin for transporting cryogenic ultrapure water for the spray icing test.

[0073] The technical solution provided by the present invention is further described in detail above in conjunction with the accompanying drawings to highlight the advantages and beneficial effects, and is not used as a limitation to the present invention. Any modifications, combinations of implementation manners, improvements, equivalent replacements, etc. based on the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling ice type in an ice test, characterized in that: The method is applied to an ice coating test on a large test piece, and the method comprises: S1: Set the air humidity in the test chamber, turn on the dehumidifier for dehumidification, and start the circulating fan to introduce low-humidity air from outside the test chamber; S2: Set the air temperature in the test chamber, start cooling, and start the circulating fan to introduce low-temperature air from outside the test chamber; S3: After the temperature in the test chamber reaches the set temperature, the background fan operating frequency is set according to the test requirements and the background fan is turned on; S4: Set the air supply pressure, open the main air supply and secondary air supply pipelines, and the compressed air generated by the air compressor is ejected through the nozzle; S5: After 10 seconds, the nozzle water supply pressure is set, the main water supply and secondary water supply pipelines are opened, and the low-temperature ultrapure water delivered by the water pump is sprayed out through the nozzle to start spraying; S6: After the test, the water supply pressure is set to 0 bar, the water valve is closed, and after 10 seconds the air supply pressure is set to 0 bar, the air valve is closed, and the spraying stops; S7: Maintain the set temperature for 30 minutes to strengthen the ice layer on the surface of the test piece; S8: The icing test is completed and the electrical equipment is turned off; The test chamber includes: an induced draft fan, a background fan, an air duct, a honeycomb panel, a spray rack, an exhaust fan, and a test piece; the test piece is placed in the internal space formed by the test chamber, and the spray rack, air duct, honeycomb panel, air duct, and background fan are installed in front of the test piece in sequence; the induced draft fan is installed at the front of the test chamber, the exhaust fan is installed at the rear, and the demister is installed at the rear of the test piece; the induced draft fan and the exhaust fan constitute a circulating fan; The circulating fan is controlled by a frequency converter, and multiple temperature sensors are used to measure the temperature values at different positions of the test piece. The average value is calculated and used as the temperature in the test chamber. When the temperature in the test chamber is higher than the set temperature +1°C, the circulating fan runs at a full frequency of 50Hz; when the temperature in the test chamber is lower than the set temperature -1°C, the circulating fan runs at a frequency of 30Hz. When the icing test is stopped, the fan stops running. The main air supply pipeline is arranged between the air compression system and the spray rack, and is used to transport all the compressed air required for the spray of the array nozzles. Seven secondary air supply pipelines are arranged on each layer of the spray rack, and are used to transport the compressed air required for the spray of the nozzles in one layer of the spray rack; the main water supply pipeline is arranged between the pre-cooling water system and the spray rack, and is used to transport all the low-temperature ultrapure water required for the spray of the array nozzles. Seven secondary water supply pipelines are arranged on each layer of the spray rack, and are used to transport the low-temperature ultrapure water required for the spray of the nozzles in one layer of the spray rack.

2. The method for controlling ice type in an ice test according to claim 1, characterized in that: The air supply pressure is monitored by a pressure transmitter, and the monitored value is fed back to the PLC industrial computer, and the electric regulating valve opening value is output after PID calculation.

3. The method for controlling ice type in an ice test according to claim 1, characterized in that: The spray nozzle is selected based on a continuously adjustable side spray rate of 5 to 50 mm / h and a spray particle size of 10 to 50 μm.

4. The method for controlling ice type in an ice test according to claim 1, characterized in that: The air supply pipeline adopts a stainless steel hose.

5. The method for controlling ice type in an ice test according to claim 1, characterized in that: The air supply flow rate of the air supply pipeline is 0.7~2.2Nm 3 / min, the inner diameter of the main air supply pipe is 40mm.

6. The method for controlling ice type in an ice test according to claim 1, characterized in that: The water supply flow rate of the main water supply pipeline is 75.6~820L / h, and the inner diameter of the main water supply pipeline is 40mm.

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