Device and method for verifying engine driving exhaust emission system in laboratory

Abstract

The invention provides a device for verifying an engine driving exhaust emission system in a laboratory, and belongs to the technical field of exhaust emission. Comprising an experiment bench used for bearing an engine, the engine arranged in the experiment bench, an exhaust pipeline used for collecting engine tail gas and injected air, a spraying cooling system integrated in the exhaust pipeline, and a back pressure control system arranged at the rear end of the exhaust pipeline. The measuring systems are arranged at different parts of the device; and the control system is used for controlling the device to work. The device integrates multivariable adjusting functions such as the shape / size of an exhaust pipeline, the water spraying amount, the back pressure and the engine working condition, and the influences of different parameters on the injection ratio, the temperature field and the pressure distribution can be tested independently or in a combined mode. An economical and efficient solution can be provided for laboratory test run of the small / micro turbojet engine; experimental data can directly guide the design of an actual airplane laboratory exhaust pipeline and an exhaust tower, and the development period is shortened.

Description

Technical Field

[0001] This invention belongs to the field of exhaust emission technology, specifically relating to a device and method for verifying the exhaust emission system of an engine in operation in a laboratory. Background Technology

[0002] Aircraft climate adaptability is an important indicator of an aircraft's ability to adapt to various extreme climatic environments and maintain its intended functions and performance throughout its entire life cycle. In the aircraft development process, assessing the adaptability of the engine and its interconnected systems under extreme environmental conditions is a crucial step.

[0003] When conducting engine driving tests in the laboratory, the design of the exhaust emission system is a core technical challenge that urgently needs to be solved. During engine operation, not only does the engine consume a large amount of cold / hot air, but it also generates a large amount of hot, high-speed exhaust gas in a short period. If this exhaust gas is not discharged in a timely manner, it will seriously affect the stability of the test site environment and endanger personnel safety.

[0004] A key technical indicator for exhaust emission systems is the control of the ejector ratio. The ejector ratio is defined as the ratio of engine exhaust emissions to the amount of ejected air. In traditional ground test benches, the ejector ratio is typically greater than 3. This means that an engine with a displacement of 100 kg / s will ultimately produce emissions exceeding 400 kg / s, and twin engines may even exceed 800 kg / s. This results in a dramatic increase in the air compensation heat load and related investment and operating costs. Therefore, in an aircraft laboratory environment, the ejector ratio should be controlled below 1 as much as possible to significantly reduce the demand for compensation air.

[0005] However, a reduced ejector ratio leads to insufficient ejector airflow, failing to fully utilize the low-temperature air to adequately cool the engine exhaust. This results in excessively high exhaust temperatures, posing serious safety hazards to concrete structures such as downstream exhaust pipes and exhaust towers. This technical contradiction presents even more complex technical challenges to the design of engine start-up exhaust systems in aircraft laboratories.

[0006] Therefore, there is an urgent need to design an experimental device that can simulate the exhaust performance of the engine under different driving conditions before the actual application of the exhaust system, so as to provide a scientific design basis and verification method for the technological development of indoor engine exhaust systems. Summary of the Invention

[0007] The purpose of this invention is to solve the problem of difficulty in verifying existing engine exhaust systems, so as to realize the verification of various exhaust performance parameters such as different engine running conditions, different exhaust pipes, exhaust gas spray cooling, and back pressure control, and to realize the automatic collection and storage of each parameter.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an apparatus for verifying an engine exhaust emission system in a laboratory setting, the apparatus comprising: an experimental bench for supporting the engine; an engine disposed within the experimental bench; an exhaust pipe for collecting engine exhaust gas and ejected air; a spray cooling system integrated within the exhaust pipe for atomizing and cooling the high-temperature exhaust gas; a back pressure control system disposed at the rear end of the exhaust pipe for adjusting exhaust resistance, thereby affecting the engine exhaust flow rate and the ejected air field; a measurement system disposed at different locations within the apparatus; and a control system for controlling the operation of the apparatus. The test bench is a relatively enclosed space, and the air inlet of the exhaust pipe extends into the test bench and is located behind the engine tail nozzle.

[0009] The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory provided by the present invention also has the following technical features: the test bench includes a rectangular test chamber, an engine bracket set inside the rectangular test chamber to support the engine, a round-to-square transition section set at the other end of the rectangular test chamber, an air intake horn for regulating the airflow, a honeycomb rectifier set at the air outlet of the air intake horn, and a circular air intake duct for connecting the honeycomb rectifier and the round-to-square transition section.

[0010] The device for verifying the exhaust gas emission system of an engine in a laboratory provided by the present invention also has the following technical feature: the engine support is provided with a thrust measurement structure for measuring thrust.

[0011] The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory, provided by this invention, also has the following technical features: the apparatus further includes a first support for supporting the experimental bench and a second support for supporting the exhaust pipe. The distance between the first bracket and the second bracket is adjustable, and both the first bracket and the second bracket are provided with pulleys for adjusting their positions.

[0012] The device for verifying the exhaust gas emission system of an engine in a laboratory provided by the present invention also has the following technical features: the spray cooling system includes a multi-stage centrifugal booster pump, a nozzle installed at the air inlet of the exhaust pipe, and a water flow meter installed on the water pipe between the multi-stage centrifugal booster pump and the nozzle.

[0013] The device for verifying the exhaust gas emission system of an engine in a laboratory provided by the present invention also has the following technical features: the back pressure control system includes a porous mixer, a plug cone, and a motor for controlling the movement of the plug cone, which are sequentially arranged at the rear end of the exhaust pipe.

[0014] The apparatus for verifying the exhaust gas emission system of an engine in a laboratory setting provided by this invention also has the following technical features: the measurement system includes a first pressure sensor for measuring the static pressure of the intake wall, an intake flow meter for measuring the intake air volume, a second pressure sensor for measuring the static pressure difference of the engine intake total pressure, a first thermometer for measuring the engine intake total temperature, a third pressure sensor for measuring the static pressure near the exhaust nozzle, a second temperature sensor for measuring the total temperature of the exhaust nozzle, a fourth pressure sensor for measuring the total pressure of the exhaust nozzle, a sensor group for measuring the exhaust pipe, and a data acquisition unit for collecting all measurement data and transmitting it to the control system.

[0015] The device for verifying the exhaust gas emission system of an engine in a laboratory provided by the present invention also has the following technical features: the control system includes a control host and multiple data display end faces, including an engine control end face, a back pressure control end face, and a measurement data real-time display end face.

[0016] Another object of the present invention is to provide a method for verifying an exhaust emission system of an engine in operation in a laboratory, the method employing the apparatus described in any of the preceding claims.

[0017] The method for verifying the exhaust emission system of an engine in operation in a laboratory, provided by this invention, also has the following technical features: the method includes: 1) Complete the installation and debugging of the experimental setup, and check the airtightness of the setup; 2) Select the pre-designed exhaust pipe, install it on the experimental platform, and check the installation of pressure and temperature sensors on the pipe; 3) By adjusting the distance Li between the engine exhaust nozzle and the pipe inlet using the pipe support, the effect of distance on ejector performance was verified; 4) Adjust the plug cone to its final position using a motor drive to ensure the open mixer area is at its maximum. 5) Oil pump test: The oil pump of the micro turbojet engine is tested via the ECU; 6) Turn on the data acquisition unit, check if the signal channel is normal, and start recording data; 7) Start the spray cooling system, adjust the multi-stage centrifugal pump pressure to 1.6MPa and the water flow meter value to 0.1kg / s; start the engine to idle speed via the main unit flight control page; 8) According to the experimental requirements, gradually adjust the engine throttle to 25%, 50%, 75%, and 100%, and run for at least 1 minute in each state. Adjust the water spray volume as needed through the spray cooling system to verify the spray cooling effect. 9) The main unit controls the motor to drive the plug cone to adjust the opening area and verify the effect of back pressure on exhaust performance; 10) Record experimental data and monitor wall pressure, total nozzle pressure, and total nozzle temperature in real time; 11) After data acquisition is completed, "stop to cool down". After the engine and exhaust pipe have cooled down, proceed to the next operating condition and repeat steps 2) to 11).

[0018] Beneficial effects: The device provided in this application integrates multi-variable adjustment functions such as exhaust pipe shape / size, water injection volume, back pressure, and engine operating conditions. It can independently or in combination test the effects of different parameters on ejector ratio, temperature field, and pressure distribution. It can provide an economical and efficient solution for laboratory testing of small / micro turbojet engines; the experimental data can directly guide the design of actual aircraft laboratory exhaust pipes and exhaust towers, shortening the development cycle. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a structural block diagram of the device provided in the embodiments of the present invention; Figure 2 This is a perspective view of the device provided in the embodiment of the present invention; Figure 3 This is a dimensional diagram of the device provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the installation position of the air intake flow meter provided in an embodiment of the present invention. Among them, 1: experimental platform; 11: air inlet bell; 12: honeycomb structure rectifier; 13: circular air inlet; 14: round to square transition section; 15: rectangular test chamber; 16: engine bracket; 2: measurement system; 21: first pressure sensor; 22: air inlet flow meter; 23: second pressure sensor; 24: first temperature sensor; 25: third pressure sensor; 26: second temperature sensor; 27: fourth pressure sensor; 28: sensor group; 29: data acquisition unit; 3: spray cooling system; 31: multi-stage centrifugal booster pump; 32: water flow meter; 33: nozzle; 4: back pressure control system; 41: porous mixer; 42: stacking cone; 43: motor; 5: engine; 6: exhaust pipe; 7: control system. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0022] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0023] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0025] like Figure 1-4 As shown, this embodiment of the invention provides an apparatus for verifying an engine exhaust emission system in a laboratory setting. The apparatus includes: an experimental bench 1 for supporting an engine 5; the engine 5 disposed within the experimental bench 1; an exhaust pipe 6 for collecting engine exhaust gas and ejected air; a spray cooling system 3 integrated within the exhaust pipe 6 for atomizing and cooling the high-temperature exhaust gas; a back pressure control system 4 disposed at the rear end of the exhaust pipe 6 for adjusting exhaust resistance and thus affecting the engine exhaust flow rate and the ejected air field; a measurement system 2 disposed at different locations of the apparatus; and a control system 7 for controlling the operation of the apparatus. The experimental bench 1 is a relatively enclosed space, and the air inlet of the exhaust pipe 6 extends into the experimental bench 1 and is positioned behind the engine exhaust nozzle.

[0026] In the above embodiment, a spray cooling system 3 is integrated into the exhaust pipe 6. By precisely controlling the spray water volume, the high-temperature exhaust gas is directly atomized and sprayed for cooling, verifying the spray cooling effect. Depending on the experimental purpose and objectives, exhaust pipes 6 of different diameters and shapes can be designed to test exhaust performance.

[0027] In some embodiments, the test bench 1 includes a rectangular test chamber 15, an engine bracket 16 disposed within the rectangular test chamber 15 to support the engine 5, a round-to-square transition section 14 disposed at the other end of the rectangular test chamber 15, an air intake horn 11 for regulating airflow, a honeycomb rectifier 12 disposed at the air outlet of the air intake horn 11, and a circular air intake duct 13 for connecting the honeycomb rectifier 12 and the round-to-square transition section 14.

[0028] In the above embodiment, the experimental rig 1 adopts a three-stage rectification structure of an air intake horn, a honeycomb rectifier, and a round-to-square transition section to form a closed rectangular test chamber. The air intake horn 11 reduces airflow resistance, the honeycomb rectifier 12 eliminates turbulent pulsations, and the round-to-square transition section 14 ensures a smooth transition of airflow to the rectangular chamber, providing stable air intake conditions for the engine 5, reducing experimental errors, and significantly improving air intake uniformity.

[0029] In some embodiments, the engine mount 16 is provided with a thrust measurement structure for measuring thrust.

[0030] In some embodiments, the device further includes a first support for supporting the experimental platform 1 and a second support for supporting the exhaust pipe 6. The distance between the first support and the second support is adjustable, and both the first support and the second support are provided with pulleys for adjusting their positions.

[0031] Traditional test benches have a fixed distance between the exhaust pipe 6 and the engine nozzle, which cannot be flexibly adjusted and can only test exhaust performance at a single distance. In the above embodiment, the exhaust pipe 6 is separated from the test bench 1 by a pulley bracket, allowing the distance between the exhaust pipe inlet and the engine nozzle to be freely adjusted by moving the bracket. This design enables researchers to study the effect of different distances on the ejection ratio. The principle is as follows: the distance between the nozzle and the exhaust pipe inlet directly affects the flow rate and velocity distribution of the ejected air. Through the adjustable structure, the distance between the tail nozzle and the exhaust tower of a real aircraft can be simulated, verifying the variation of the ejection ratio with distance.

[0032] In some embodiments, the spray cooling system 3 includes a multi-stage centrifugal booster pump 31, a nozzle 33 installed at the air inlet of the exhaust pipe 6, and a water flow meter 32 installed on the water pipe between the multi-stage centrifugal booster pump 31 and the nozzle 33.

[0033] In some embodiments, the back pressure control system 4 includes a porous mixer 41, a plug cone 42, and a motor 43 for controlling the movement of the plug cone 42, which are sequentially arranged at the rear end of the exhaust pipe 6.

[0034] In the above embodiment, the plug cone 42 driven by the motor 43 is combined with the porous mixer 41. By adjusting the position of the plug cone 42, the effective opening area of ​​the porous mixer 41 is dynamically changed, thereby adjusting the exhaust resistance and realizing real-time adjustable back pressure. The change in back pressure directly affects the engine exhaust flow rate and the ejected air field.

[0035] In some embodiments, the measurement system 2 includes a first pressure sensor 21 for measuring the static pressure of the intake wall, an intake flow meter 22 for measuring the intake air volume, a second pressure sensor 23 for measuring the static pressure difference of the engine intake total pressure, a first thermometer 24 for measuring the engine intake total temperature, a third pressure sensor 25 for measuring the static pressure near the exhaust nozzle, a second temperature sensor 26 for measuring the total temperature of the exhaust nozzle, a fourth pressure sensor 27 for measuring the total pressure of the exhaust nozzle, a sensor group 28 for measuring the exhaust pipe, and a data acquisition unit 29 for collecting all measurement data and transmitting it to the control system.

[0036] In the above embodiments, the measuring instruments include: absolute pressure sensor, differential pressure sensor, pressure scanning valve, K-type armored thermocouple, infrared monitoring probe, and data acquisition devices EX1000A, VTI1048, etc.

[0037] In some embodiments, the control system 7 includes a control host and multiple data display end faces, including an engine control end face, a back pressure control end face, and a measurement data real-time display end face.

[0038] In some embodiments, a method for verifying an engine exhaust emission system in a laboratory setting is provided, the method comprising: 1) Complete the installation and debugging of the experimental setup, and check the airtightness of the setup; 2) Select the pre-designed exhaust pipe 6, install it on the experimental frame 1, and check the installation of pressure and temperature sensors on the pipe; 3) By adjusting the distance Li between the engine exhaust nozzle and the pipe inlet using the pipe support, the effect of distance on ejector performance was verified; 4) Drive the plug cone 42 to its final position using motor 43 to ensure that the area of ​​the open mixer is at its maximum. 5) Oil pump test: The oil pump of the micro turbojet engine is tested via the ECU; 6) Turn on the data acquisition unit 29, check if the signal channel is normal, and start recording data; 7) Start the spray cooling system, adjust the pressure of the multi-stage centrifugal pump 31 to 1.6MPa and the water flow meter 32 to 0.1kg / s; start the engine to idle speed via the main unit flight control page; 8) According to the experimental requirements, gradually adjust the engine throttle to 25%, 50%, 75%, and 100%, and run for at least 1 minute in each state. Adjust the water spray volume as needed through the spray cooling system 3 to verify the spray cooling effect. 9) The main unit controls the motor 43 to drive the plug cone 42 to adjust the opening area and verify the effect of back pressure on exhaust performance; 10) Record experimental data and monitor wall pressure, total nozzle pressure, and total nozzle temperature in real time; 11) After data acquisition is completed, “stop to cool down”. After the engine 5 and exhaust pipe 6 have cooled down, proceed to the next operating condition and repeat steps 2) to 11).

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An apparatus for verifying exhaust emission systems of a laboratory engine during operation, characterized in that, The device includes: an experimental stand (1) for supporting the engine (5), the engine (5) installed in the experimental stand (1), an exhaust pipe (6) for collecting engine exhaust gas and ejected air, a spray cooling system (3) integrated in the exhaust pipe (6) for atomizing and cooling the high-temperature exhaust gas, a back pressure control system (4) installed at the rear end of the exhaust pipe (6) for adjusting the exhaust resistance and thus affecting the engine exhaust flow rate and ejected air field, a measurement system (2) installed at different parts of the device, and a control system (7) for controlling the operation of the device. The test bench (1) is a relatively enclosed space, and the air inlet of the exhaust pipe (6) extends into the test bench (1) and is placed behind the engine tail nozzle.

2. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 1, characterized in that, The experimental bench (1) includes a rectangular test chamber (15), an engine bracket (16) set inside the rectangular test chamber (15) to support the engine (5), a round-to-square transition section (14) set at the other end of the rectangular test chamber (15), an air inlet horn (11) for regulating the airflow, a honeycomb rectifier (12) set at the air outlet of the air inlet horn (11), and a circular air intake duct (13) for connecting the honeycomb rectifier (12) and the round-to-square transition section (14).

3. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 2, characterized in that, The engine mount (16) is provided with a thrust measurement structure for measuring thrust.

4. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 1, characterized in that, The device also includes a first support for supporting the experimental platform and a second support for supporting the exhaust pipe. The distance between the first bracket and the second bracket is adjustable, and both the first bracket and the second bracket are provided with pulleys for adjusting their positions.

5. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 1, characterized in that, The spray cooling system (3) includes a multi-stage centrifugal booster pump (31), a nozzle (33) installed at the air inlet of the exhaust pipe (6), and a water flow meter (31) installed on the water pipe between the multi-stage centrifugal booster pump (31) and the nozzle (33).

6. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 1, characterized in that, The back pressure control system (4) includes a porous mixer (41), a plug cone (42), and a motor (43) for controlling the movement of the plug cone (42) arranged sequentially at the rear end of the exhaust pipe (6).

7. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 1, characterized in that, The measurement system (2) includes a first pressure sensor (21) for measuring the static pressure of the intake wall, an intake flow meter (22) for measuring the intake air volume, a second pressure sensor (23) for measuring the static pressure difference of the total intake pressure of the engine, a first thermometer (24) for measuring the total intake temperature of the engine, a third pressure sensor (25) for measuring the static pressure near the exhaust nozzle, a second temperature sensor (26) for measuring the total temperature of the exhaust nozzle, a fourth pressure sensor (27) for measuring the total pressure of the exhaust nozzle, a sensor group (28) for measuring the exhaust pipe, and a data acquisition unit (29) for collecting all the measurement data and sending it to the control system.

8. The apparatus for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 1, characterized in that, The control system (7) includes a control host and multiple data display end faces, including an engine control end face, a back pressure control end face, and a measurement data real-time display end face.

9. A method for verifying an exhaust emission system of an engine in operation in a laboratory, characterized in that, The method employs the apparatus as described in any one of claims 1-8.

10. The method for verifying the exhaust emission system of an engine in operation in a laboratory according to claim 9, characterized in that, The method includes: 1) Complete the installation and debugging of the experimental setup, and check the airtightness of the setup; 2) Select the pre-designed exhaust pipe 6, install it on the experimental frame 1, and check the installation of pressure and temperature sensors on the pipe; 3) By adjusting the distance Li between the engine tail nozzle and the exhaust pipe 6 inlet using the pipe bracket, the effect of distance on ejector performance was verified; 4) Drive the plug cone 42 to its final position using motor 43 to ensure that the area of ​​the open mixer is at its maximum. 5) Oil pump test: The oil pump of the micro turbojet engine is tested via the ECU; 6) Turn on the data acquisition unit, check if the signal channel is normal, and start recording data; 7) Start the spray cooling system, adjust the pressure of the multi-stage centrifugal pump 31 to 1.6MPa and the water flow meter 32 to 0.1kg / s; start the engine 5 to idle speed via the main unit flight control page; 8) According to the experimental requirements, gradually adjust the engine throttle to 25%, 50%, 75%, and 100%, and run for at least 1 minute in each state. Adjust the water spray volume as needed through the spray cooling system 3 to verify the spray cooling effect. 9) The main unit controls the motor 43 to drive the plug cone 42 to adjust the opening area and verify the effect of back pressure on exhaust performance; 10) Record experimental data and monitor wall pressure, total nozzle pressure, and total nozzle temperature in real time; 11) After data acquisition is completed, "stop the car to cool down". After the engine and exhaust pipe have cooled down, proceed to the next operating condition and repeat steps 2) to 11).

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