Self-adaptive test system and method for cooling performance of turbine blade

Abstract

The invention provides a self-adaptive test system and method for the cooling performance of a turbine blade. The self-adaptive test system comprises a supply system, an acquisition control system and a vacuum chamber, under the control of the collection control system, the supply system provides cooling air for turbine blades located in the vacuum chamber and provides inlet fuel gas for the turbine blades. The supply system comprises a heat source supply unit and a cooling gas supply unit, the heat source supply unit provides inlet gas for turbine blades, and the cooling gas supply unit provides cooling air for the turbine blades. The problem caused by slow movement of a traditional stepping motor is solved through the machine learning technology, and the experiment implementation cost is greatly reduced.

Description

Technical Field

[0001] The present invention belongs to the field of aeroengines, and specifically relates to an adaptive test system and method for turbine blade cooling performance, and more particularly to an adaptive test system and method for studying turbine blade cooling performance. Background Art

[0002] Today's advanced aircraft engines, as the main power source for aircraft and other aircraft, are developing towards high thrust-to-weight ratio, high reliability, environmental protection and long life.

[0003] Therefore, for aircraft engines, increasing the temperature of the combustion chamber is extremely important for improving engine performance, such as increasing engine thrust, improving engine efficiency and engine thrust-to-weight ratio.

[0004] But at the same time, this will also bring new problems. For example, increasing the temperature of the combustion chamber will inevitably push up the temperature of the turbine inlet gas. At present, the turbine inlet gas temperature of advanced aviation turbofan engines has reached 1800K~2050K, which exceeds the limit temperature that the high-temperature resistant turbine blade material can withstand. Therefore, a large amount of cooling air must be used to reduce the wall temperature of the turbine blade.

[0005] For example, the research objectives of the engine turbine in the Integrated High Performance Turbine Engine Technology (IHPTET) program launched by the US Department of Defense are: to increase the gas inlet temperature before the turbine by 500K, reduce cooling air by 60%, reduce weight by 50%, increase single-stage load by 50%, and reduce production and maintenance costs by 10%.

[0006] Therefore, the development of turbine technology includes not only the increase of inlet temperature and the reduction of weight, but also the reduction of cooling air.

[0007] Patent document CN101403654A discloses a dual-fluid cooling experimental system for gas turbine turbine blades. The system reduces cooling air by introducing cooling steam as a cooling fluid to achieve the purpose of cooling the turbine blades.

[0008] Foreign research shows that CMC ceramic composite turbine blades can withstand temperatures above 1200°C, which is more than 100°C higher than that of high-temperature alloys. They can reduce cooling air by more than 20%, which is far from the goal of reducing cooling air by 60%.

[0009] Since the temperature of the gas inlet to the turbine blades is different in different flight sections of the aircraft, the cooling requirements for the turbine blades are also different. Since the aircraft is in the subsonic cruise stage most of the time, the gas temperature at the turbine outlet is low, and the required cooling air flow is also low.

[0010] Therefore, in order to further reduce the amount of cooling air used, on the basis of using composite turbine blades, it is necessary to intelligently adjust the amount of cooling air used according to the turbine inlet temperature so that more air can participate in combustion, reduce fuel consumption, and at the same time achieve the purpose of further reducing the amount of cooling air used.

[0011] When designing traditional aircraft engine turbines, the main consideration is the maximum amount of cooling air for the turbine blades under the worst operating conditions, and there is little research on the amount of cooling air required to maintain a certain temperature for the turbine blades in different flight segments of the aircraft.

[0012] At present, domestic aviation research institutes generally use wind tunnels to conduct turbine cooling tests, placing turbine blades in the wind duct. In order to simulate the turbine inlet gas, two methods are adopted: one is to use an ultra-high power heater to heat the air, and the other is to use a real aircraft engine combustion chamber. These two methods require huge investments, and many companies and universities cannot afford the economic pressure. At the same time, these two methods are also difficult to implement. Summary of the invention

[0013] In view of the defects in the prior art, an object of the present invention is to provide an adaptive test system and method for turbine blade cooling performance.

[0014] According to the present invention, an adaptive test system for turbine blade cooling performance is provided, comprising: a supply system, a collection control system, and a vacuum chamber 4;

[0015] Under the control of the acquisition control system, the supply system provides cooling air to the turbine blades 22 located in the vacuum chamber 4 and provides inlet fuel gas to the turbine blades 22;

[0016] The supply system comprises: a heat source supply unit and a cooling gas supply unit;

[0017] The heat source supply unit provides inlet fuel gas to the turbine blades 22 , and the cooling gas supply unit provides cooling air to the turbine blades 22 .

[0018] Preferably, the heat source supply unit comprises: a high-pressure nitrogen cylinder 1, a first pressure reducer 2, an alcohol storage tank 3, a high-pressure oxygen cylinder 6, a high-pressure solenoid valve 7, a first safety valve 8, a buffer tank 9, an exhaust solenoid valve 10, a first pressure sensor 11, and a mass flow meter 17;

[0019] The heat source supply unit uses gas oxygen and / or alcohol as working fluid;

[0020] The heat source supply unit is divided into two branches: one is that the nitrogen in the high-pressure nitrogen cylinder 1 pressurizes the alcohol storage tank 3 through the first pressure reducer 2, and the other is that the oxygen in the high-pressure oxygen cylinder 6 enters the buffer tank 9 through the high-pressure solenoid valve 7;

[0021] When the pipeline pressure exceeds the set safety pressure, the first safety valve 8 can open to release the pressure in the buffer tank 9;

[0022] The buffer tank 9 is provided with the first pressure sensor 11, the first safety valve 8 is connected to the oxygen supply branch of the gas-oxygen alcohol engine 5, and the buffer tank 9 is provided with the exhaust branch of the exhaust solenoid valve 10. When the high-pressure solenoid valve 7 fails and causes the buffer tank 9 to exceed the set safety pressure, the first safety valve 8 will perform a pressure relief operation according to the set pressure;

[0023] The mass flow meter 17 is arranged between the alcohol storage tank 3 and the vacuum chamber 4 to monitor the flow of the propellant in real time.

[0024] The gas-oxygen alcohol engine 5 comprises: a fuel solenoid valve 501, a spark plug 502, an oxygen solenoid valve 503, and a chamber pressure interface 504;

[0025] The gas-oxygen-alcohol engine 5 is placed in a vacuum chamber 4, the inlet of the oxygen solenoid valve 503 is connected to the oxygen supply branch, and the propellant supply branch is connected to the inlet of the fuel solenoid valve 501. The two branches meet at the head of the gas-oxygen-alcohol engine 5 and burn in the combustion chamber under the action of the spark plug 502. Finally, the high-temperature combustion gas ejected from the nozzle serves as the mainstream combustion gas for the inlet of the turbine blades 22. In the vacuum chamber 4, the indoor pressure can be monitored in real time through the chamber pressure interface 504.

[0026] Preferably, the cooling air flow supply unit comprises: a high-pressure nitrogen cylinder 1, a second pressure reducer 12, the filter 13, a second pressure sensor 14, the solenoid valve 15, a third pressure sensor 16, the mass flow meter 17, a second safety valve 18, a needle valve 19, a stepping motor 20, and a fourth pressure sensor 21;

[0027] The cooling air flow supply unit uses nitrogen as a working fluid; the nitrogen in the high-pressure nitrogen bottle 1 passes through the second pressure reducer 12, the filter 13, the solenoid valve 15, the mass flow meter 17, and the needle valve 19 in sequence, and reaches the surface of the turbine blade 22 for cooling;

[0028] The second pressure sensor 14, the third pressure sensor 16, the second safety valve 18, the stepping motor 20, and the fourth pressure sensor 21 are sequentially installed between the second pressure reducer 12 and the vacuum chamber 4;

[0029] The cooling nitrogen passes through the second pressure reducer 12, the filter 13, the solenoid valve 15, the mass flow meter 17, and the needle valve 19 in sequence, and reaches the surface of the turbine blade 22 for cooling.

[0030] Preferably, the needle valve 19 comprises: a needle valve housing 201, a conical surface 202, and a threaded rod 203;

[0031] The threaded rod 203 can drive the conical surface 202 to reciprocate in the needle valve housing 201 along the central axis of the inner wall of the housing; a pressure sensor is arranged before and after the needle valve 19: the third pressure sensor 16 and the fourth pressure sensor 21 obtain the throttling condition of the needle valve 19 through pressure difference processing, and the mass flow meter 17 is arranged in front of the needle valve 19 to obtain the flow rate of the cooling gas, and multiple temperature measuring points are arranged on the turbine blades 22 to obtain the gas cooling effect.

[0032] Preferably, the vacuum chamber 4 is provided with: a gas-oxygen alcohol engine 5, a turbine blade 22, a first temperature sensor 23, a fifth pressure sensor 24, and a second temperature sensor 25;

[0033] The height of the turbine blade 22 is smaller than the nozzle diameter of the gas-oxygen-alcohol engine 5, and the straight-line distance between the turbine blade 22 and the nozzle is equal to the nozzle diameter;

[0034] The first temperature sensor 23 collects the temperature of the turbine blade 22, and the second temperature sensor 25 can collect the temperature inside the vacuum chamber 4;

[0035] The fifth pressure sensor 24 can collect the pressure inside the vacuum chamber 4 .

[0036] Preferably, the acquisition control system comprises: a main control computer, an acquisition computer, and a control computer;

[0037] Under the control of the main control computer: the acquisition computer collects various temperature, pressure and flow data; the control computer controls the stepper motor 20 and various solenoid valves;

[0038] The acquisition computer controls the following components to acquire data: the second pressure sensor 14, the third pressure sensor 16, the needle valve 19, the fourth pressure sensor 21, the first temperature sensor 23, the fifth pressure sensor 24, and the second temperature sensor 25;

[0039] Under the control of the control computer:

[0040] When the pressure data of the buffer tank 9 is lower than the set pressure, the control computer will open the high-pressure solenoid valve 7, and the high-pressure oxygen cylinder 6 will pressurize the buffer tank 9, and will close the high-pressure solenoid valve 7 when the set pressure is reached; when the collected pressure data of the buffer tank 9 is higher than the set pressure, the control computer will open the exhaust solenoid valve 10, and will close the exhaust solenoid valve 10 when it drops to the set pressure; since the collected pressure of the buffer tank 9 has a hysteresis, and the gas-oxygen-alcohol engine 5 will cause pressure drop and fluctuation when working, the opening time and closing interval of the high-pressure solenoid valve 7 or the exhaust solenoid valve 10 are obtained according to the pressure of the buffer tank 9, the working time and interval time of the gas-oxygen-alcohol engine 5, and the flow parameters through machine learning methods.

[0041] Preferably, based on the temperature data of the turbine blade 22 collected by the collection computer, when the temperature exceeds the set value, the control computer controls the stepping motor 20 to drive the conical surface 202 of the needle valve 19 to move, the flow area of ​​the needle valve 19 will become larger, and the cooling gas will flow into the turbine blade 22 through the needle valve 19. If the temperature continues to rise, the control computer controls to increase the step number of the stepping motor 20, and the flow area of ​​the needle valve 19 will continue to increase, thereby passing a larger cooling gas flow. If the temperature starts to drop, the control computer controls to reduce the step number of the stepping motor 20, the conical surface 202 of the needle valve 19 will move in the opposite direction, the flow area of ​​the needle valve 19 will decrease, and the cooling gas flow will decrease until the temperature data of the turbine blade 22 stabilizes near the set temperature value of the turbine blade 22.

[0042] The number of steps of the stepper motor 20 is determined according to the pressure variation law at the chamber pressure interface 504 in the gas-oxygen-alcohol engine 5, and the number of steps required by the stepper motor 20 in different flight sections is obtained through machine learning methods.

[0043] A test method of an adaptive test system for turbine blade cooling performance provided by the present invention includes:

[0044] Step S4: adding alcohol to the alcohol storage tank 3 and instructing the control computer to pump the pressure of the vacuum chamber 4 to below 50Pa;

[0045] Step S5: instructing the control computer to operate the first pressure reducer 2 and the second pressure reducer 12 to press the high-pressure nitrogen from the high-pressure nitrogen bottle 1 into the alcohol storage tank 3, and the propellant in the alcohol storage tank 3 is sent to the fuel solenoid valve 501 of the gas-oxygen-alcohol engine 5 through the delivery pipeline under the action of pressure;

[0046] Step S6: the high-pressure solenoid valve 7 is used to deliver oxygen into the buffer tank 9, and the oxygen in the buffer tank 9 is squeezed through the oxygen pipeline and enters in front of the oxygen solenoid valve 503 in the gas-oxygen-alcohol engine 5;

[0047] Step S7: Open the second pressure reducer 12 in the cooling pipeline, and send the nitrogen to the needle valve 19 through the filter 13 and the mass flow meter 17;

[0048] Step S8: the control computer is used to start the spark plug 502 to start working, and then the oxygen solenoid valve 503 is opened to allow oxygen to be sprayed into the combustion chamber in advance. After the fuel solenoid valve 501 is opened, the gas-oxygen-alcohol engine 5 starts to ignite, and after ignition, the spark plug 502 is closed;

[0049] Step S9: instructing the control computer to set a new lower pressure value, the control computer will issue an instruction to open the exhaust solenoid valve 10 in the buffer tank 9 until the buffer tank 9 reaches the new design pressure, set a new higher pressure value in the control computer, open the high-pressure solenoid valve 7 until the buffer tank 9 reaches the new design pressure, and record the alcohol flow rate and oxygen flow rate through the mass flow meter 17 during the test run; wherein, the mixing ratio of the gas-oxygen-alcohol engine 5 is adjusted by adjusting the oxygen inlet pressure;

[0050] Step S10: Conduct a heat source test run and obtain the mixing ratio of various tank pressures through a computer;

[0051] Step S11: opening the vacuum chamber 4 and placing the turbine blades 22 into the vacuum chamber 4;

[0052] Step S12: subjecting the turbine blades 22 to a cooling test.

[0053] Step S13: After the test run, the relationship curve between the total temperature and the mixing ratio is obtained through the main control computer.

[0054] Preferably, when the first temperature sensor 23 and the second temperature sensor 25 on the turbine blade 22 measure that the turbine blade 22 reaches the set value, the control computer controls the stepper motor 20 to drive the threaded rod 203 to rotate, causing the conical surface 202 of the needle valve 19 to move, the flow area of ​​the needle valve 19 to increase, and the cooling nitrogen flows into the surface of the turbine blade 22 through the needle valve 19 to further cool the turbine blade 22. If the temperature continues to rise, the number of steps of the stepper motor 20 is increased, and the flow area of ​​the needle valve 19 continues to increase, passing a larger nitrogen flow rate. If the temperature begins to drop, the number of steps of the stepper motor 20 is reduced, the conical surface 202 of the needle valve 19 moves in the opposite direction, the flow area of ​​the needle valve 19 is reduced, and the nitrogen flow rate decreases until the temperature of the turbine blade 22 stabilizes at the set value of the turbine blade 22; the real-time flow rate of the cooling nitrogen in the pipeline is obtained by the mass flowmeter 17.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. The present invention proposes a buffer tank solution to avoid manual on-site adjustment using a pressure reducer, which not only significantly improves the adjustment accuracy, but also reduces the risk of personal injury due to oxygen leakage.

[0057] 2. The present invention mainly conducts experiments based on rocket gas-oxygen-alcohol engines, which reduces the development costs of fuel gas or high-temperature hot gas generating devices.

[0058] 3. The vacuum chamber solution proposed by the present invention reduces the development cost required for building a large wind tunnel.

[0059] 4. The present invention proposes a solution of combining an acquisition control system, a stepper motor and a needle valve. This solution can automatically adjust the cooling flow rate based on factors such as the temperature of the composite turbine blades, the temperature change rate and the change trend of the total incoming pressure, thereby achieving an adaptive response to the cooling needs of the turbine blades and thereby improving the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0061] Figure 1 It is a schematic diagram of the structure of an adaptive test system based on turbine blade cooling performance in an embodiment of the present invention;

[0062] Figure 2 A schematic diagram of a needle valve of an adaptive test system based on turbine blade cooling performance in an embodiment of the present invention;

[0063] Figure 3A schematic diagram of an air-oxygen alcohol engine of an adaptive test system based on turbine blade cooling performance in an embodiment of the present invention;

[0064] Figure 4 This is a schematic diagram of a curve showing the relationship between the mixing ratio and the total outlet temperature in an air-oxygen-alcohol engine of an adaptive test system based on turbine blade cooling performance in an embodiment of the present invention.

[0065] The figure shows:

[0066] DETAILED DESCRIPTION

[0067] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0068] The present invention provides an adaptive test system for turbine blade cooling performance, comprising: a supply system, a collection and control system, and a vacuum chamber 4.

[0069] Under the control of the acquisition control system, the supply system provides cooling air to the turbine blades 22 located in the vacuum chamber 4 , and provides inlet fuel gas to the turbine blades 22 .

[0070] The supply system includes: a heat source supply unit and a cooling gas supply unit.

[0071] The heat source supply unit provides inlet fuel gas to the turbine blades 22 , and the cooling gas supply unit provides cooling air to the turbine blades 22 ; the turbine blades 22 are made of composite materials.

[0072] The heat source supply unit includes: a high-pressure nitrogen cylinder 1, a first pressure reducer 2, an alcohol storage tank 3, a high-pressure oxygen cylinder 6, a high-pressure solenoid valve 7, a first safety valve 8, a buffer tank 9, an exhaust solenoid valve 10, a first pressure sensor 11, and a mass flow meter 17;

[0073] The heat source supply unit uses gaseous oxygen and / or alcohol as working fluid. The heat source supply unit is divided into two branches: one is that the nitrogen in the high-pressure nitrogen cylinder 1 pressurizes the alcohol storage tank 3 through the first pressure reducer 2, and the other is that the oxygen in the high-pressure oxygen cylinder 6 enters the buffer tank 9 through the high-pressure solenoid valve 7.

[0074] When the pipeline pressure exceeds the set safety pressure, the first safety valve 8 can be opened to release the pressure in the buffer tank 9.

[0075] The buffer tank 9 is provided with the first pressure sensor 11, the first safety valve 8 is connected to the oxygen supply branch of the gas-oxygen-alcohol engine 5, and the buffer tank 9 is provided with the exhaust branch of the exhaust solenoid valve 10. When the high-pressure solenoid valve 7 fails and causes the buffer tank 9 to exceed the set safety pressure, the first safety valve 8 will perform a pressure relief operation according to the set pressure.

[0076] The buffer tank 9 adopts the voltage stabilization function in the control computer, based on the buffer tank 9 pressure data collected by the collection computer, when the collected buffer tank 9 pressure data is lower than the set pressure, the control computer will open the high-pressure solenoid valve 7, and the high-pressure oxygen cylinder 6 will pressurize the buffer tank 9, and will close the high-pressure solenoid valve 7 when the set pressure is reached; when the collected buffer tank 9 pressure data is higher than the set pressure, the control computer will open the exhaust solenoid valve 10, and will close the exhaust solenoid valve 10 when it drops to the set pressure; because the collected pressure of the buffer tank 9 has hysteresis, and the gas-oxygen-alcohol engine 5 will cause pressure drop and fluctuation when working, based on the above reasons, the present invention obtains the opening time and closing interval of the high-pressure solenoid valve 7 or the exhaust solenoid valve 10 according to the pressure of the buffer tank 9, the working time and interval time of the gas-oxygen-alcohol engine 5, the flow rate and other parameters through machine learning methods, thereby reducing the pressure fluctuation of the buffer tank 9.

[0077] The mass flow meter 17 is installed at different positions according to actual needs to monitor the flow of the current pipeline, such as being installed between the alcohol storage tank 3 and the vacuum chamber 4 to monitor the flow of the propellant in real time.

[0078] The cooling air flow supply unit includes: the high-pressure nitrogen cylinder 1, the second pressure reducer 12, the filter 13, the second pressure sensor 14, the solenoid valve 15, the third pressure sensor 16, the mass flow meter 17, the second safety valve 18, the needle valve 19, the stepping motor 20, and the fourth pressure sensor 21.

[0079] The cooling air flow supply unit uses nitrogen as the working fluid. The nitrogen in the high-pressure nitrogen bottle 1 passes through the second pressure reducer 12, the filter 13, the solenoid valve 15, the mass flow meter 17, and the needle valve 19 in sequence to reach the surface of the turbine blade 22 for cooling.

[0080] The second pressure sensor 14 , the third pressure sensor 16 , the second safety valve 18 , the stepping motor 20 , and the fourth pressure sensor 21 are sequentially installed between the second pressure reducer 12 and the vacuum chamber 4 .

[0081] The vacuum chamber 4 is provided with: an oxygen-gas alcohol engine 5 (i.e., a thrust chamber), turbine blades 22 , a first temperature sensor 23 , a fifth pressure sensor 24 , and a second temperature sensor 25 .

[0082] The height of the turbine blade 22 is smaller than the nozzle diameter of the gas-oxygen-alcohol engine 5, and the straight-line distance between the turbine blade 22 and the nozzle is equal to the diameter of the nozzle.

[0083] The first temperature sensor 23 detects the temperature of the turbine blade 22 , and the second temperature sensor 25 can detect the temperature inside the vacuum chamber 4 .

[0084] The fifth pressure sensor 24 can collect the pressure inside the vacuum chamber 4 .

[0085] The gas-oxygen alcohol engine 5 comprises: a fuel solenoid valve 501, a spark plug 502, an oxygen solenoid valve 503, and a chamber pressure interface 504. The gas-oxygen alcohol engine 5 is placed in a vacuum chamber 4, the inlet of the oxygen solenoid valve 503 is connected to the oxygen supply branch, and the propellant supply branch is connected to the inlet of the fuel solenoid valve 501. The two branches meet at the head of the gas-oxygen alcohol engine 5, and burn in the combustion chamber under the action of the spark plug 502, and finally the high-temperature combustion gas ejected from the nozzle serves as the mainstream combustion gas at the inlet of the turbine blade 22. The gas-oxygen alcohol engine 5 provides combustion gas for warming the turbine blade 22, and the stable supply of oxygen is realized by the automatic control of the high-pressure solenoid valve 7 at the inlet of the buffer tank 9 and the exhaust solenoid valve 10 at the bottom. The cooling nitrogen passes through the second pressure reducer 12, the filter 13, the solenoid valve 15, the mass flowmeter 17, and the needle valve 19 in sequence, and reaches the surface of the turbine blade 22 for cooling.

[0086] The indoor pressure in the vacuum chamber 4 can be monitored in real time through the chamber pressure interface 504. The needle valve 19 comprises: a needle valve housing 201, a conical surface 202, and a threaded rod 203.

[0087] The threaded rod 203 can drive the conical surface 202 to reciprocate along the central axis of the inner wall of the needle valve housing 201. A pressure sensor is provided before and after the needle valve 19: the third pressure sensor 16 and the fourth pressure sensor 21, and the throttling condition of the needle valve 19 is obtained by pressure difference processing. The mass flow meter 17 is provided in front of the needle valve 19 to obtain the flow rate of the cooling gas, and multiple temperature measurement points are provided on the turbine blades 22 to obtain the gas cooling effect.

[0088] The needle valve 19 adopts the adaptive adjustment function in the control computer. Based on the temperature data of the turbine blade 22 collected by the collection computer, when the temperature exceeds the set value, the control computer controls the stepper motor 20 to drive the conical surface 202 of the needle valve 19 to move, and the flow area of ​​the needle valve 19 will become larger, and the cooling gas will flow into the turbine blade 22 through the needle valve 19, thereby achieving the effect of cooling the turbine blade 22. If the temperature continues to rise, the control computer controls to increase the step number of the stepper motor 20, and the flow area of ​​the needle valve 19 will continue to increase, thereby passing a larger cooling gas flow rate. If the temperature begins to drop, the control computer controls to reduce the step number of the stepper motor 20, the conical surface 202 of the needle valve 19 will move in the opposite direction, the flow area of ​​the needle valve 19 will decrease, and the cooling gas flow rate will decrease until the temperature data of the turbine blade 22 stabilizes near the set temperature value of the turbine blade 22. Since the screw of the stepper motor 20 takes a long time to rotate one circle, and when simulating the turbine inlet temperature of the aircraft in different flight sections, it is necessary to determine the number of steps of the stepper motor 20 according to the pressure change law at the chamber pressure interface 504 in the gas-oxygen-alcohol engine 5. Based on these practical needs, the present invention uses a machine learning method to obtain the number of steps required for the stepper motor 20 in different flight sections.

[0089] The acquisition control system comprises: a main control computer, an acquisition computer and a control computer.

[0090] Under the control of the main control computer: the acquisition computer collects various temperature, pressure and flow data; the control computer controls the stepper motor 20 and various solenoid valves.

[0091] The acquisition computer controls the following components to acquire data: the second pressure sensor 14 , the third pressure sensor 16 , the needle valve 19 , the fourth pressure sensor 21 , the first temperature sensor 23 , the fifth pressure sensor 24 , and the second temperature sensor 25 .

[0092] The second pressure sensor 14 and the third pressure sensor 16 are installed in sequence between the second pressure reducer 12 and the vacuum chamber 4 .

[0093] A pressure sensor is respectively arranged before and after the needle valve 19: the third pressure sensor 16 and the fourth pressure sensor 21, and the throttling condition of the needle valve 19 is obtained by pressure difference processing.

[0094] The first temperature sensor 23 can monitor the temperature of the turbine blade 22 in real time, the second temperature sensor 25 can monitor the temperature of the vacuum chamber 4 in real time, and the fifth pressure sensor 24 can monitor the pressure of the vacuum chamber 4 in real time.

[0095] The control computer controls the following components: high-pressure solenoid valve 7 , exhaust solenoid valve 10 , solenoid valve 15 , fuel solenoid valve 501 , spark plug 502 , and oxygen solenoid valve 503 .

[0096] Under the control of the control computer:

[0097] When the pressure data of the buffer tank 9 is lower than the set pressure, the control computer will open the high-pressure solenoid valve 7, and the high-pressure oxygen cylinder 6 will pressurize the buffer tank 9, and will close the high-pressure solenoid valve 7 when the set pressure is reached; when the collected pressure data of the buffer tank 9 is higher than the set pressure, the control computer will open the exhaust solenoid valve 10, and will close the exhaust solenoid valve 10 when it drops to the set pressure; since the collected pressure of the buffer tank 9 has hysteresis, and the gas-oxygen-alcohol engine 5 will cause pressure drop and fluctuation when working, based on the above reasons, the present invention obtains the opening time and closing interval of the high-pressure solenoid valve 7 or the exhaust solenoid valve 10 according to the pressure of the buffer tank 9, the working time and interval time of the gas-oxygen-alcohol engine 5, the flow rate and other parameters through machine learning methods, thereby reducing the pressure fluctuation of the buffer tank 9.

[0098] The solenoid valve 15 is installed between the filter 13 and the mass flow meter 17 .

[0099] The inlet of the oxygen solenoid valve 503 is connected to the oxygen supply branch, and the propellant supply branch is connected to the inlet of the fuel solenoid valve 501. These two branches meet at the head of the gas-oxygen-alcohol engine 5, and burn in the combustion chamber under the action of the spark plug 502. Finally, the high-temperature combustion gas ejected from the nozzle serves as the mainstream combustion gas at the inlet of the turbine blade 22.

[0100] In this way, the adaptive test system for turbine blade cooling performance realizes the adaptive regulation function of fuel gas and cooling nitrogen and the pressure stabilization function of oxygen.

[0101] The present invention provides an adaptive test method for turbine blade cooling performance, referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , including the following steps:

[0102] Step S1: Check whether the equipment required for the test is in good condition, clean the alcohol storage tank 3 and pipelines and other equipment, and blow them dry with nitrogen for later use.

[0103] Step S2: Assembling the test system.

[0104] Specifically, the gas-oxygen-alcohol engine 5, the needle valve 19, the stepper motor 20, etc. are connected together with pipelines, and various temperature sensors, various pressure sensors and other acquisition components are connected to form an acquisition circuit, and various solenoid valves, the stepper motor 20 and other control components are connected to form a control circuit. The turbine blades 22 are not installed temporarily, and the pipe ends are blocked by plugging.

[0105] Step S3: Check the air tightness of the system.

[0106] Specifically, the valves of the first pressure reducer 2 and the second pressure reducer 12 of the high-pressure nitrogen cylinder 1 and the high-pressure solenoid valve 7 of the high-pressure oxygen cylinder 6 are opened, and adjusted so that the pipeline has a certain pressure, the valves of the first pressure reducer 2 and the second pressure reducer 12 of the high-pressure nitrogen cylinder 1 and the high-pressure solenoid valve 7 in the high-pressure oxygen cylinder 6 are closed, and the pressure data of the alcohol storage tank 3, the buffer tank 9 and the cooling pipeline are recorded. After a period of time, such as: after 15 minutes, if the air pressure indication does not change, the air tightness is good.

[0107] Step S4: Add alcohol into the alcohol storage tank 3, and instruct the control computer to pump the pressure of the vacuum chamber 4 to below 50Pa.

[0108] Step S5: instruct the control computer to operate the first pressure reducer 2 and the second pressure reducer 12 to press the high-pressure nitrogen from the high-pressure nitrogen bottle 1 into the alcohol storage tank 3. The propellant in the alcohol storage tank 3 is sent to the fuel solenoid valve 501 of the gas-oxygen-alcohol engine 5 through a delivery pipeline under the action of pressure.

[0109] Step S6: the high-pressure solenoid valve 7 delivers oxygen into the buffer tank 9, and the oxygen in the buffer tank 9 is squeezed through the oxygen pipeline into the oxygen solenoid valve 503 in the gas-oxygen-alcohol engine 5.

[0110] Step S7: Open the second pressure reducer 12 in the cooling pipeline, and send the nitrogen to the needle valve 19 through the filter 13 and the mass flow meter 17.

[0111] Step S8: The control computer controls the spark plug 502 to start working, and after 3 seconds, the oxygen solenoid valve 503 is opened to allow oxygen to be sprayed into the combustion chamber 1 second in advance. After the fuel solenoid valve 501 is opened, the gas-oxygen-alcohol engine 5 starts to ignite, and after 2 seconds of ignition, the spark plug 502 is closed.

[0112] Step S9: Instruct the control computer to set a new lower pressure value, and the control computer will issue an instruction to open the exhaust solenoid valve 10 in the buffer tank 9 until the buffer tank 9 reaches the new design pressure, set a new higher pressure value in the control computer, open the high-pressure solenoid valve 7 until the buffer tank 9 reaches the new design pressure, and record the alcohol flow rate and oxygen flow rate through the mass flow meter 17 during the test run. The mixing ratio of the gas-oxygen-alcohol engine 5 (i.e., the ratio of oxygen flow rate to alcohol flow rate) is adjusted by adjusting the oxygen inlet pressure.

[0113] Step S10: Conduct a heat source test run and obtain the mixing ratio of various tank pressures through a data acquisition computer.

[0114] Step S11: Open the vacuum chamber 4 and add the turbine blade 22 into the vacuum chamber 4, wherein the turbine blade 22 is about 80 mm away from the nozzle of the gas-oxygen-alcohol engine 5;

[0115] Step S12: subjecting the turbine blades 22 to a cooling test.

[0116] Specifically, when the first temperature sensor 23 and the second temperature sensor 25 on the turbine blade 22 detect that the turbine blade 22 reaches the set value, the control computer controls the stepper motor 20 to drive the threaded rod 203 to rotate, causing the conical surface 202 of the needle valve 19 to move, the flow area of ​​the needle valve 19 to increase, and the cooling nitrogen flows into the surface of the turbine blade 22 through the needle valve 19, further cooling the turbine blade 22. If the temperature continues to rise, the number of steps of the stepper motor 20 is increased, and the flow area of ​​the needle valve 19 continues to increase, and a larger nitrogen flow rate is passed. If the temperature begins to drop, the number of steps of the stepper motor 20 is reduced, and the conical surface 202 of the needle valve 19 moves in the opposite direction, the flow area of ​​the needle valve 19 is reduced, and the nitrogen flow rate decreases until the temperature of the turbine blade 22 stabilizes at the set value of the turbine blade 22. The real-time flow rate of the cooling nitrogen in the pipeline is obtained by the mass flowmeter 17.

[0117] Step S13: After the test run, the relationship curve between the total temperature and the mixing ratio is obtained through the main control computer.

[0118] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. An adaptive test system for turbine blade cooling performance, characterized in that: include: Supply system, collection control system, vacuum chamber (4); Under the control of the acquisition control system, the supply system provides cooling air to the turbine blades (22) located in the vacuum chamber (4), and provides inlet fuel gas to the turbine blades (22); The supply system comprises: a heat source supply unit and a cooling gas supply unit; The heat source supply unit provides inlet combustion gas to the turbine blades (22), and the cooling gas supply unit provides cooling air to the turbine blades (22).

2. The adaptive test system for turbine blade cooling performance according to claim 1, characterized in that: The heat source supply unit comprises: a high-pressure nitrogen cylinder (1), a first pressure reducer (2), an alcohol storage tank (3), a high-pressure oxygen cylinder (6), a high-pressure solenoid valve (7), a first safety valve (8), a buffer tank (9), an exhaust solenoid valve (10), a first pressure sensor (11), and a mass flow meter (17); The heat source supply unit uses gas oxygen and / or alcohol as working fluid; The heat source supply unit is divided into two branches: one branch is for the nitrogen in the high-pressure nitrogen bottle (1) to pressurize the alcohol storage tank (3) through the first pressure reducer (2), and the other branch is for the oxygen in the high-pressure oxygen bottle (6) to enter the buffer tank (9) through the high-pressure solenoid valve (7); When the pipeline pressure exceeds the set safety pressure, the first safety valve (8) can open to release the pressure from the buffer tank (9); The buffer tank (9) is provided with the first pressure sensor (11), the first safety valve (8) is connected to the oxygen supply branch of the gas-oxygen alcohol engine (5), and the buffer tank (9) is provided with the exhaust branch of the exhaust solenoid valve (10). When the high-pressure solenoid valve (7) fails and causes the buffer tank (9) to exceed the set safety pressure, the first safety valve (8) will perform a pressure relief operation according to the set pressure; The mass flow meter (17) is arranged between the alcohol storage tank (3) and the vacuum chamber (4) to monitor the flow of the propellant in real time.

3. The adaptive test system for turbine blade cooling performance according to claim 2, characterized in that: The gas-oxygen alcohol engine (5) comprises: a fuel solenoid valve (501), a spark plug (502), an oxygen solenoid valve (503), and a chamber pressure interface (504); The gas-oxygen alcohol engine (5) is placed in a vacuum chamber (4); the inlet of the oxygen solenoid valve (503) is connected to the oxygen supply branch, and the propellant supply branch is connected to the inlet of the fuel solenoid valve (501); these two branches meet at the head of the gas-oxygen alcohol engine (5) and burn in the combustion chamber under the action of the spark plug (502); finally, the high-temperature combustion gas ejected from the nozzle serves as the mainstream combustion gas for the inlet of the turbine blade (22); the indoor pressure in the vacuum chamber (4) can be monitored in real time through the chamber pressure interface (504).

4. The adaptive test system for turbine blade cooling performance according to claim 1, characterized in that: The cooling air flow supply unit comprises: a high-pressure nitrogen bottle (1), a second pressure reducer (12), a filter (13), a second pressure sensor (14), a solenoid valve (15), a third pressure sensor (16), a mass flow meter (17), a second safety valve (18), a needle valve (19), a stepping motor (20), and a fourth pressure sensor (21); The cooling air flow supply unit uses nitrogen as a working fluid; the nitrogen in the high-pressure nitrogen bottle (1) passes through the second pressure reducer (12), the filter (13), the solenoid valve (15), the mass flow meter (17), and the needle valve (19) in sequence, and reaches the surface of the turbine blade (22) for cooling; The second pressure sensor (14), the third pressure sensor (16), the second safety valve (18), the stepping motor (20), and the fourth pressure sensor (21) are sequentially installed between the second pressure reducer (12) and the vacuum chamber (4); The cooling nitrogen gas passes through the second pressure reducer (12), the filter (13), the solenoid valve (15), the mass flow meter (17), and the needle valve (19) in sequence, and reaches the surface of the turbine blade (22) for cooling.

5. The adaptive test system for turbine blade cooling performance according to claim 4, characterized in that: The needle valve (19) comprises: a needle valve housing (201), a conical surface (202), and a threaded rod (203); The threaded rod (203) can drive the conical surface (202) to reciprocate in the needle valve housing (201) along the central axis of the inner wall of the housing; a pressure sensor is respectively arranged before and after the needle valve (19): the third pressure sensor (16) and the fourth pressure sensor (21), and the throttling condition of the needle valve (19) is obtained through pressure difference processing; the mass flow meter (17) is arranged in front of the needle valve (19) to obtain the flow rate of the cooling gas, and a plurality of temperature measurement points are arranged on the turbine blade (22) to obtain the gas cooling effect.

6. The adaptive test system for turbine blade cooling performance according to claim 1, characterized in that: The vacuum chamber (4) is provided with: an oxygen-gas alcohol engine (5), turbine blades (22), a first temperature sensor (23), a fifth pressure sensor (24), and a second temperature sensor (25); The height of the turbine blade (22) is smaller than the nozzle diameter of the gas-oxygen-alcohol engine (5), and the straight-line distance between the turbine blade (22) and the nozzle is equal to the diameter of the nozzle; The first temperature sensor (23) collects the temperature of the turbine blade (22), and the second temperature sensor (25) can collect the temperature inside the vacuum chamber (4); The fifth pressure sensor (24) is capable of collecting the pressure inside the vacuum chamber (4).

7. The adaptive test system for turbine blade cooling performance according to claim 1, characterized in that: The acquisition control system comprises: a main control computer, an acquisition computer, and a control computer; Under the control of the main control computer: the acquisition computer acquires various temperature, pressure and flow data; the control computer controls the stepping motor (20) and various electromagnetic valves; The acquisition computer controls the following components to acquire data: a second pressure sensor (14), a third pressure sensor (16), a needle valve (19), a fourth pressure sensor (21), a first temperature sensor (23), a fifth pressure sensor (24), and a second temperature sensor (25); Under the control of the control computer: When the pressure data of the buffer tank (9) is lower than the set pressure, the control computer will open the high-pressure solenoid valve (7), and the high-pressure oxygen cylinder (6) will pressurize the buffer tank (9), and when the set pressure is reached, the high-pressure solenoid valve (7) will be closed; when the collected pressure data of the buffer tank (9) is higher than the set pressure, the control computer will open the exhaust solenoid valve (10), and when the pressure drops to the set pressure, the exhaust solenoid valve (10) will be closed; because the collected pressure of the buffer tank (9) has hysteresis, and the gas-oxygen-alcohol engine (5) will cause pressure drop and fluctuation when it is working, according to the pressure of the buffer tank (9), the working time and interval time of the gas-oxygen-alcohol engine (5), and the flow parameters, the opening time and closing interval of the high-pressure solenoid valve (7) or the exhaust solenoid valve (10) are obtained through machine learning methods.

8. The adaptive test system for turbine blade cooling performance according to claim 7, characterized in that: Based on the temperature data of the turbine blade (22) collected by the collection computer, when the temperature exceeds the set value, the control computer controls the number of steps of the stepping motor (20) to drive the conical surface (202) of the needle valve (19) to move, the flow area of ​​the needle valve (19) will become larger, and the cooling gas will flow into the turbine blade (22) through the needle valve (19); if the temperature continues to rise, the control computer controls to increase the number of steps of the stepping motor (20), the flow area of ​​the needle valve (19) will continue to increase, thereby passing a larger cooling gas flow; if the temperature starts to drop, the control computer controls to reduce the number of steps of the stepping motor (20), the conical surface (202) of the needle valve (19) will move in the opposite direction, the flow area of ​​the needle valve (19) will decrease, and the cooling gas flow will decrease, until the temperature data of the turbine blade (22) stabilizes near the set temperature value of the turbine blade (22); The number of steps of the stepper motor (20) is determined according to the pressure variation law at the chamber pressure interface (504) in the gas-oxygen-alcohol engine (5), and the number of steps required by the stepper motor (20) in different flight sections is obtained through a machine learning method.

9. A test method using the adaptive test system for turbine blade cooling performance according to any one of claims 1 to 8, characterized in that: include: Step S4: adding alcohol to the alcohol storage tank (3), and instructing the control computer to evacuate the pressure of the vacuum chamber (4) to a vacuum level below 50 Pa; Step S5: instructing the control computer to operate the first pressure reducer (2) and the second pressure reducer (12) to press the high-pressure nitrogen from the high-pressure nitrogen bottle (1) into the alcohol storage tank (3); the propellant in the alcohol storage tank (3) is sent to the fuel solenoid valve (501) of the gas-oxygen-alcohol engine (5) through a delivery pipeline under the action of pressure; Step S6: the high-pressure electromagnetic valve (7) is used to deliver oxygen into the buffer tank (9), and the oxygen in the buffer tank (9) is squeezed through the oxygen pipeline and enters in front of the oxygen electromagnetic valve (503) in the gas-oxygen alcohol engine (5); Step S7: Open the second pressure reducer (12) in the cooling pipeline, and send the nitrogen to the front of the needle valve (19) through the filter (13) and the mass flow meter (17); Step S8: the control computer is used to start the spark plug (502) to start working, and then the oxygen solenoid valve (503) is opened to allow oxygen to be sprayed into the combustion chamber in advance. After the fuel solenoid valve (501) is opened, the gas-oxygen-alcohol engine (5) starts to ignite, and after ignition, the spark plug (502) is closed; Step S9: instructing the control computer to set a new lower pressure value, the control computer will issue an instruction to open the exhaust solenoid valve (10) in the buffer tank (9) until the buffer tank (9) reaches the new design pressure, set a new higher pressure value in the control computer, open the high-pressure solenoid valve (7) until the buffer tank (9) reaches the new design pressure, and record the alcohol flow rate and oxygen flow rate through the mass flow meter (17) during the test run; wherein, the mixing ratio of the gas-oxygen-alcohol engine (5) is adjusted by adjusting the oxygen inlet pressure; Step S10: Conducting a heat source test run, and obtaining the mixing ratio of various storage tank pressures through the acquisition computer; Step S11: opening the vacuum chamber (4) and placing the turbine blade (22) into the vacuum chamber (4); Step S12: subjecting the turbine blade (22) to a cooling test; Step S13: After the test run, the relationship curve between the total temperature and the mixing ratio is obtained through the main control computer.

10. The test method of claim 9 using the adaptive test system for turbine blade cooling performance according to any one of claims 1 to 8, characterized in that: When the first temperature sensor (23) and the second temperature sensor (25) on the turbine blade (22) detect that the turbine blade (22) has reached a set value, the control computer controls the stepping motor (20) to drive the threaded rod (203) to rotate, causing the conical surface (202) of the needle valve (19) to move, and the flow area of ​​the needle valve (19) to increase. The cooling nitrogen flows into the surface of the turbine blade (22) through the needle valve (19), and further the cooling of the turbine blade (22). If When the temperature continues to rise, the number of steps of the stepping motor (20) is increased, and the flow area of ​​the needle valve (19) continues to increase, and a larger nitrogen flow rate is passed; if the temperature begins to drop, the number of steps of the stepping motor (20) is reduced, and the conical surface (202) of the needle valve (19) moves in the opposite direction, the flow area of ​​the needle valve (19) is reduced, and the nitrogen flow rate decreases until the temperature of the turbine blade (22) stabilizes at the set value of the turbine blade (22); the real-time flow rate of the cooling nitrogen in the pipeline is obtained through the mass flow meter (17).

Images