High-temperature and high-pressure calibration wind tunnel and throttling adjustment method thereof

Abstract

The invention discloses a high-temperature and high-pressure calibration wind tunnel and a throttling adjusting method thereof. The high-temperature and high-pressure calibration wind tunnel comprises an air compressor air source, an emptying adjusting valve, an air inlet adjusting valve, a mass flow meter, a heating device, a stable section, a test section, a spraying cooling device, a back pressure adjusting valve, a data acquisition system and a control system. An air source of the air compressor is a fixed-frequency continuous air source, the control system performs closed-loop control on the air inlet regulating valve and the emptying regulating valve by taking the air inlet flow as a closed-loop control feedback point, performs closed-loop control on the back pressure regulating valve by taking the static pressure of the test section as a closed-loop control feedback point, and calculates the airflow Mach number of the test section according to the total pressure of the stable section and the static pressure of the test section; and closed-loop continuous adjustment of the airflow Mach number of the test section is realized by controlling the emptying adjusting valve, the air inlet adjusting valve and the back pressure adjusting valve. According to the invention, the wide-range multi-working-condition continuous adjustment of the high-temperature and high-pressure thermal calibration wind tunnel can be realized under the condition of a fixed-frequency continuous air source, the calibration capability of the thermal calibration wind tunnel is improved, and the development cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of temperature measurement and testing, and in particular relates to a high-temperature and high-pressure calibration wind tunnel and a throttling adjustment method thereof. Background Art

[0002] Temperature measurement is an important part of equipment design verification and iterative optimization. For example, in the process of aircraft engine design and development and ground testing, it is necessary to measure the airflow temperature in engine inlet, compressor, combustion chamber, turbine, tail nozzle and other components. The accuracy of temperature measurement is of great significance to improving engine combustion efficiency, enhancing thrust / thrust-to-weight ratio performance and ensuring reliability. The development of high-temperature and high-pressure calibration wind tunnel is of great significance to ensuring the measurement accuracy of temperature sensors. According to HB 7485-2012 "Test Method for Combustion Chamber Performance of Aviation Gas Turbine Engines", the error of airflow temperature sensors that are not calibrated and corrected by standard hot wind tunnels can reach a deviation of up to 300K, and the error of combustion efficiency calculated using uncorrected data can reach 30%.

[0003] In the development of high-temperature and high-pressure thermal calibration wind tunnels, in order to meet the calibration requirements of different sensors, it is often necessary to reach more operating points, which requires the wind tunnel to have good dynamic adjustment capabilities in a large range, especially for the case of a fixed-frequency continuous gas source, it is necessary to consider the continuous adjustment of airflow pressure, airflow temperature, and airflow Mach number at the same time. At present, there are two throttling adjustment methods: gate finger and control valve. Especially for high temperature conditions (above 1700℃), gate finger adjustment needs to overcome the problems of temperature resistance of the actuator and high-precision processing of the finger surface. The development cost and difficulty are often several times higher than that of the control valve, and the development technology of the control valve is more mature than that of the gate finger mechanism. Therefore, for high-temperature calibration wind tunnels, it is more economical to use a control valve to adjust the working conditions than a gate finger mechanism. Summary of the invention

[0004] The purpose of the present invention is to provide a high-temperature and high-pressure calibration wind tunnel and a throttling adjustment method thereof, which can realize continuous adjustment of the high-temperature and high-pressure thermal calibration wind tunnel in a wide range and multiple working conditions under the conditions of a fixed-frequency continuous gas source, thereby improving the calibration capability of the thermal calibration wind tunnel and reducing the development cost.

[0005] One aspect of the present invention provides a high-temperature and high-pressure calibration wind tunnel, including an air compressor source, an exhaust regulating valve, an air intake regulating valve, a mass flow meter, a heating device, a stabilization section, a test section, a spray cooling device, a back pressure regulating valve, a data acquisition system, and a control system;

[0006] The air compressor gas source is a fixed-frequency continuous gas source. Part of the gas from the air compressor gas source enters the exhaust pipeline through the exhaust regulating valve, and the other part enters the intake pipeline through the intake regulating valve, and then enters the exhaust pipeline through the gas mass flow meter, the heating device, the stable section, the test section, the spray cooling device, and the back pressure regulating valve in sequence. The heating device is used to heat the gas, the spray cooling device is used to spray and cool the gas, the gas mass flow meter is used to measure the intake flow rate, the wall surface of the test section is provided with a static pressure measuring point, and the stable section is provided with a total pressure measuring point;

[0007] The data acquisition system is used to collect the valve opening of the exhaust regulating valve, the intake regulating valve, the back pressure regulating valve, the static pressure of the test section, the total pressure of the stable section and the intake flow rate, and transmit the collected parameters to the control system;

[0008] The control system is used to set the intake flow rate, Mach number and pressure parameters according to the parameter requirements of the test operating point, and based on the parameters collected by the data acquisition system, perform closed-loop control on the intake control valve and the exhaust control valve with the intake flow rate as the closed-loop control feedback point, and perform closed-loop control on the back pressure control valve with the static pressure of the test section as the closed-loop control feedback point, calculate the Mach number of the test section airflow according to the total pressure of the stable section and the static pressure of the test section, and achieve closed-loop continuous adjustment of the Mach number of the test section airflow by controlling the exhaust control valve, the intake control valve and the back pressure control valve.

[0009] Preferably, the distance between the spray cooling device and the back pressure regulating valve is ≥10D, where D is the nominal diameter of the pipeline before the valve.

[0010] Preferably, the exhaust regulating valve, the air intake regulating valve and the back pressure regulating valve are plunger regulating valves or butterfly valves with a regulating dead zone range less than 10%.

[0011] Preferably, the nominal diameter of the exhaust regulating valve is not greater than the nominal diameter of the intake regulating valve, the air flow velocity of the exhaust pipeline is 40m / s to 50m / s, and the air flow velocity of the intake pipeline is 20m / s to 30m / s.

[0012] Preferably, the air source of the air compressor is a fixed-frequency continuous air source.

[0013] Another aspect of the present invention provides a throttling adjustment method for a high temperature and high pressure calibration wind tunnel, wherein throttling adjustment is performed on the above-mentioned high temperature and high pressure calibration wind tunnel, the method comprising:

[0014] The intake flow rate, Mach number and pressure parameters are set according to the parameter requirements of the test operating conditions; the intake flow rate is used as the closed-loop control feedback point to perform closed-loop control on the intake regulating valve and the exhaust regulating valve; the static pressure of the test section is used as the closed-loop control feedback point to perform closed-loop control on the back pressure regulating valve; the Mach number of the test section airflow is calculated based on the total pressure of the stable section and the static pressure of the test section, so as to achieve closed-loop continuous adjustment of the Mach number and pressure of the test section airflow.

[0015] The high-temperature and high-pressure calibration wind tunnel and the throttling adjustment method thereof according to the above aspects of the present invention can realize continuous adjustment of the high-temperature and high-pressure thermal calibration wind tunnel in a wide range and multiple working conditions under the condition of a constant-frequency continuous gas source, thereby improving the calibration capability of the thermal calibration wind tunnel and reducing the development cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0017] Figure 1 is a schematic structural diagram of a high temperature and high pressure calibration wind tunnel according to an embodiment of the present invention;

[0018] Among them, 1 is the air source of the air compressor, 2 is the exhaust regulating valve, 3 is the air intake regulating valve, 4 is the mass flow meter, 5 is the heating device, 6 is the stable section, 7 is the test section, 8 is the spray cooling device, and 9 is the back pressure regulating valve. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] An embodiment of the present invention provides a high temperature and high pressure calibration wind tunnel, such as Figure 1 As shown, the high-temperature and high-pressure calibration wind tunnel of the embodiment of the present invention includes an air compressor source 1, an exhaust regulating valve 2, an air intake regulating valve 3, a mass flow meter 4, a heating device 5, a stabilization section 6, a test section 7, a spray cooling device 8, a back pressure regulating valve 9, a data acquisition system and a control system, and each section is connected in sequence.

[0021] The air intake regulating valve 3 is located between the air source 1 and the heating device 5 upstream of the wind tunnel, the exhaust regulating valve 2 is located on the branch road between the air intake regulating valve 2 and the air source 1, the spray cooling section where the spray cooling device 8 is located is located after the test section 7, and the back pressure regulating valve 9 is a certain distance behind the spray cooling section. Part of the dry pressurized gas from the air source 1 enters the exhaust pipeline through the exhaust regulating valve 2, and the remaining part enters the heating device 5 through the air intake regulating valve 3, and then enters the stable section 6 and the test section 7 in turn. After passing through the spray cooling device 8, it enters the exhaust pipeline through the back pressure regulating valve 9. The heating device 5 is used to heat the gas, and the spray cooling device 8 is used to spray and cool the gas. A gas mass flowmeter 4 is installed after the air intake regulating valve 3 of the main air intake line to measure the intake flow rate.

[0022] The data acquisition system is used to collect parameters such as valve opening of the exhaust regulating valve 2, the intake regulating valve 3, and the back pressure regulating valve 9, the static pressure of the test section, the total pressure of the stable section, and the intake flow rate, and transmit the collected parameters to the control system. The control system is used to set the intake flow rate, Mach number, and pressure parameters according to the test operating point parameter requirements, and control the exhaust regulating valve 2, the intake regulating valve 3, and the back pressure regulating valve 9 according to the parameters collected by the data acquisition system.

[0023] Specifically, the intake regulating valve 3 and the exhaust regulating valve 2 are adjusted with the intake flow rate as the closed-loop control feedback point; a static pressure measuring point is set on the wall of the test section 7 in front of the back pressure regulating valve 9, and the back pressure regulating valve 9 is adjusted with the static pressure of the test section as the closed-loop control feedback point; a total pressure measuring point is set in the stable section 6 of the wind tunnel, and the total pressure of the airflow can be measured by the total pressure probe of the stable section 6 of the wind tunnel in combination with a pressure sensor and an atmospheric pressure gauge, and the static pressure of the airflow can be measured by the static pressure hole of the test section 7 in combination with a pressure sensor and an atmospheric pressure gauge, and then the Mach number of the airflow in the test section is calculated based on the total pressure of the airflow and the static pressure of the airflow, and the Mach number of the airflow in the test section is adjusted continuously in a closed loop.

[0024] When the test section 7 requires a higher temperature, it will exceed the upper temperature limit of the valve. Therefore, a spray cooling device 8 is added in front of the back pressure regulating valve 9 for spray cooling. A certain distance L needs to be kept between the spray cooling device 8 and the back pressure regulating valve 9. Generally, L≥10D, where D is the nominal diameter of the pipeline before the valve.

[0025] The valve types of the exhaust regulating valve 2, the intake regulating valve 3, and the back pressure regulating valve 9 are plunger regulating valves or butterfly valves with a regulating dead zone range of less than 10%.

[0026] The nominal diameter of the exhaust regulating valve 2 is not greater than the nominal diameter of the intake regulating valve 3 , the air flow velocity of the exhaust pipeline is controlled at 40m / s to 50m / s, and the air flow velocity of the intake pipeline is controlled at 20m / s to 30m / s.

[0027] The throttling adjustment method of the high-temperature and high-pressure calibration wind tunnel of the embodiment of the present invention is as follows: the control system determines the intake flow rate, Mach number, and pressure parameters according to the parameter requirements of the test operating point. Turn on the gas source 1 and start the data acquisition system. The data acquisition system mainly collects parameters such as valve opening, temperature, pressure, and mass flow: the valve opening is output to the data acquisition system in the form of (4-20) mA signal by the exhaust regulating valve 2, the intake regulating valve 3, and the back pressure regulating valve 9. The temperature measurement point is located in the core area of ​​the test section 7, and the temperature signal is collected by the temperature probe and the temperature transmitter, and then the (4-20) mA signal is output to the data acquisition system through the temperature transmitter. The total pressure measurement point is located in the core area of ​​the stable section 6, and the static pressure measurement point is located on the wall of the test section 7. The pressure signal is collected by the pressure probe and the pressure transmitter, and then the (4-20) mA signal is output to the data acquisition system through the pressure transmitter. The data acquisition system transmits the collected parameters to the control system.

[0028] The control system adjusts the exhaust regulating valve 2 and the air intake regulating valve 3 to keep the air intake flow stable, then turns on the heating device 5 and the spray cooling device 8, and adjusts the back pressure regulating valve 9 after the temperature of the test section 7 stabilizes. When the Mach number and pressure of the test section 7 meet the requirements and stabilize, the calibrated temperature sensor data is recorded. After recording, it is adjusted to the next operating point according to this adjustment sequence.

[0029] The feedback control process of the airflow Mach number is as follows: when the Mach number needs to be increased: PID self-tuning will increase the intake flow rate, send action instructions to the intake control valve 3 and the exhaust control valve 2, the intake control valve 3 opening increases, and the exhaust control valve 2 opening decreases; PID self-tuning will reduce the static pressure of the test section 7, send an action instruction to the back pressure control valve 9, and the back pressure control valve 9 opening increases. In this way, the high-temperature and high-pressure calibration wind tunnel throttling adjustment method realizes the closed-loop continuous adjustment of the Mach number and pressure of the wind tunnel test section.

[0030] After the data collection of all working points is completed, the heating device 5, the spray cooling device 8, the air compressor gas source 1, and the data collection system are turned off in sequence.

[0031] In summary, the high-temperature and high-pressure calibration wind tunnel and its throttling adjustment method in the embodiment of the present invention can simultaneously meet the continuous adjustment of multiple calibration conditions such as the airflow Mach number, temperature, and pressure in the wind tunnel test section under the condition of a constant-frequency continuous air source through the PID closed-loop control of the three valves, namely the air intake control valve, the exhaust control valve, and the back-pressure control valve, and meet different calibration conditions, effectively reducing the development cost and difficulty of the high-temperature and high-pressure calibration wind tunnel, and realizing the continuous adjustment of multiple calibration conditions of the wind tunnel under the condition of a constant-frequency air source.

[0032] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high temperature and high pressure calibration wind tunnel, characterized in that: It includes air compressor source, exhaust regulating valve, air intake regulating valve, mass flow meter, heating device, stabilization section, test section, spray cooling device, back pressure regulating valve, data acquisition system and control system; The air compressor gas source is a fixed-frequency continuous gas source. Part of the gas from the air compressor gas source enters the exhaust pipeline through the exhaust regulating valve, and the other part enters the intake pipeline through the intake regulating valve, and then enters the exhaust pipeline through the gas mass flow meter, the heating device, the stable section, the test section, the spray cooling device, and the back pressure regulating valve in sequence. The heating device is used to heat the gas, the spray cooling device is used to spray and cool the gas, the gas mass flow meter is used to measure the intake flow rate, the wall surface of the test section is provided with a static pressure measuring point, and the stable section is provided with a total pressure measuring point; The data acquisition system is used to collect the valve opening of the exhaust regulating valve, the intake regulating valve, the back pressure regulating valve, the static pressure of the test section, the total pressure of the stable section and the intake flow rate, and transmit the collected parameters to the control system; The control system is used to set the intake flow rate, Mach number and pressure parameters according to the parameter requirements of the test operating point, and based on the parameters collected by the data acquisition system, perform closed-loop control on the intake control valve and the exhaust control valve with the intake flow rate as the closed-loop control feedback point, and perform closed-loop control on the back pressure control valve with the static pressure of the test section as the closed-loop control feedback point, calculate the Mach number of the test section airflow according to the total pressure of the stable section and the static pressure of the test section, and achieve closed-loop continuous adjustment of the Mach number of the test section airflow by controlling the exhaust control valve, the intake control valve and the back pressure control valve.

2. The high temperature and high pressure calibration wind tunnel according to claim 1, characterized in that: The distance between the spray cooling device and the back pressure regulating valve is ≥10D, where D is the nominal diameter of the pipeline before the valve.

3. The high temperature and high pressure calibration wind tunnel according to claim 1 or 2, characterized in that: The exhaust regulating valve, the air intake regulating valve and the back pressure regulating valve are plunger regulating valves or butterfly valves with a regulating dead zone range of less than 10%.

4. The high temperature and high pressure calibration wind tunnel according to claim 1 or 2, characterized in that: The nominal diameter of the exhaust regulating valve is not greater than the nominal diameter of the intake regulating valve. The air flow velocity of the exhaust pipeline is 40m / s~50m / s, and the air flow velocity of the intake pipeline is 20m / s~30m / s.

5. The high temperature and high pressure calibration wind tunnel according to claim 1 or 2, characterized in that: The air compressor air source is a fixed-frequency continuous air source.

6. A throttling adjustment method for a high temperature and high pressure calibration wind tunnel, characterized in that: A method for throttling a high-temperature and high-pressure calibration wind tunnel according to any one of claims 1 to 5, the method comprising: The intake flow rate, Mach number and pressure parameters are set according to the parameter requirements of the test operating conditions; the intake flow rate is used as the closed-loop control feedback point to perform closed-loop control on the intake regulating valve and the exhaust regulating valve; the static pressure of the test section is used as the closed-loop control feedback point to perform closed-loop control on the back pressure regulating valve; the Mach number of the test section airflow is calculated based on the total pressure of the stable section and the static pressure of the test section, so as to achieve closed-loop continuous adjustment of the Mach number and pressure of the test section airflow.

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