Centrifugal compressor test system for small turbojet engine

Abstract

The invention discloses a centrifugal compressor test system for a small turbojet engine, and relates to the technical field of turbojet engines. Comprising a centrifugal compressor, an air inlet system, an exhaust system, a lubricating oil system, a cooling water system, a starting system, a data collecting and processing system, an air inlet and exhaust adjusting control system and a safety monitoring system. The device can measure airflow parameters including total pressure, static pressure, total temperature and the like of an inlet, a rotor, a diffuser and an outlet of the centrifugal compressor, judges whether design indexes of pressure ratio, flow, efficiency and surge margin are reached or not according to test results, and provides data support for performance evaluation and design modification of the centrifugal compressor.

Description

Technical Field

[0001] The invention relates to the technical field of turbojet engines, in particular to a centrifugal compressor test system for a small turbojet engine. Background Art

[0002] Turbojet engines have the advantages of light weight, small size, high cruising speed, strong maneuverability and high reliability. They have been widely used in many fields, such as target drones, cruise missiles, and UAVs. With the continuous improvement of aircraft flight missions and performance requirements, the research on turbojet engines has also become a key research direction. The compressor, combustion chamber and turbine are collectively called the "core engine" of the aircraft engine. It is one of the important components of the engine. The performance of the compressor directly affects the overall performance of the turbojet engine and even the entire aircraft.

[0003] Small turbojet engines mostly use single-stage centrifugal compressors with high pressure ratios. The compressor performance parameters can be theoretically calculated and analyzed with the help of numerical simulation. However, in engineering development, it is still necessary to actually measure the performance parameters of the centrifugal compressor through compressor tests and evaluate the stable operating range of the centrifugal compressor. Summary of the invention

[0004] Therefore, in order to solve the above-mentioned shortcomings, the present invention provides a centrifugal compressor test system for a small turbojet engine.

[0005] The present invention is implemented by constructing a centrifugal compressor test system for a small turbojet engine, the device comprising a centrifugal compressor, an air intake system, an exhaust system, a lubricating oil system, a cooling water system, a starting system, a data acquisition and processing system, an air intake and exhaust regulation control system and a safety monitoring system;

[0006] The air intake system is used to introduce outside air into the engine in the centrifugal compressor with less flow loss, and calculate the air flow entering the engine by measuring the total pressure, static pressure and other parameters on the flow tube, including a dust screen, an air intake duct and a fixed bracket; the exhaust system is used to discharge the high-pressure gas discharged from the centrifugal compressor through the volute out of the test system, including an exhaust volute and some mounting parts; the lubricating oil system is responsible for the lubrication of various components of the test system, including the compressor, transmission device, starting system, etc. The lubricating oil system components include a lubricating oil tank, lubricating oil pipeline, oil thermometer, and oil pressure regulating valve; the cooling water system is responsible for the test system The cooling system includes water supply and drainage pipelines, cooling towers or pools and other facilities; the starting system is used to provide the rotational speed and torque to the centrifugal compressor and transmit the signal to the data processing system, including a transmission device, a dynamometer and a controller; the data acquisition and processing system is used to sample, process and output the signals of each subsystem; the intake and exhaust adjustment control system is responsible for controlling the intake system, exhaust system and air pipeline, and communicating with the data acquisition and processing system to complete the relevant signal transmission and processing; the safety monitoring system is used to quickly make fault diagnosis and alarm when an abnormality is found in the test system during operation.

[0007] Preferably, the data measurements collected in the data acquisition and processing system specifically include inlet cross-section measurement, outlet cross-section measurement, rotor blade rear parameter measurement, wall static pressure measurement, flow channel static pressure measurement, surge detection, torque and speed measurement, lubricating oil system temperature and pressure measurement and cooling water system temperature measurement, and auxiliary system parameter measurement.

[0008] Preferably, the inlet cross-section measurement in the data acquisition and processing system includes a multi-point total pressure probe for detecting inlet total pressure measurement, a thermocouple for detecting inlet total temperature measurement and a flow tube for detecting air flow; the outlet cross-section measurement in the data acquisition and processing system includes a radially moving rake-shaped total pressure probe for detecting outlet total pressure measurement, a radially moving multi-point total temperature probe for detecting outlet total temperature measurement and a five-hole pneumatic probe for detecting airflow direction and turbulence parameter measurement.

[0009] Preferably, the measurement of the rear parameters of the rotor blades in the data acquisition and processing system is specifically to set total pressure and total temperature measuring points in front of the stator blades to measure the rear parameters of the rotor blades; the measurement of the wall static pressure in the data acquisition and processing system is specifically to open static pressure holes on the inner and outer walls of each measuring section, with a hole diameter of 0.5 to 1.0 mm and a center line perpendicular to the airflow direction.

[0010] Preferably, the static pressure measurement in the flow channel in the data acquisition and processing system is specifically to measure the static pressure distribution of the airflow in the centrifugal compressor rotor and diffuser flow channel with a single-point static pressure probe; the surge detection in the data acquisition and processing system is specifically to detect the compressor inlet and outlet pulsating pressure by a dynamic test system composed of a dynamic pressure sensor and supporting instruments, and when the measured pressure suddenly changes, it is regarded as an unstable working state;

[0011] Preferably, the torque and speed measurement in the data acquisition and processing system is specifically connected to the starting system through a transmission device, the starting system measures the speed and torque of the compressor rotor shaft, the speed is read by a speed sensor, and the starting system and the speed sensor are mutually verified.

[0012] Preferably, the centrifugal compressor, air intake system, exhaust system, lubricating oil system, cooling water system, starting system, data acquisition and processing system, air intake and exhaust regulation and control system and safety monitoring system of the test system are assembled to form a test bench body, which specifically includes a centrifugal compressor, a mounting bracket, an air intake device, an exhaust volute, a transmission device, a dynamometer, a sensor assembly and a control terminal.

[0013] The present invention has the following advantages: The present invention provides a centrifugal compressor test system for a small turbojet engine through improvement, which has the following improvements compared with similar equipment:

[0014] The centrifugal compressor test system for a small turbojet engine described in the present invention can measure the airflow parameters at the inlet, rotor, diffuser and outlet of the centrifugal compressor, including total pressure, static pressure, total temperature, etc., and judge whether the design indicators of pressure ratio, flow rate, efficiency and surge margin are met based on the test results, so as to provide data support for the performance evaluation and design modification of the centrifugal compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the layout of the test system of the present invention;

[0016] Figure 2 It is a schematic diagram of the test bench structure of the present invention;

[0017] Figure 3 It is a schematic diagram of the exhaust volute structure in the exhaust system of the present invention;

[0018] Figure 4 The present invention Figure 3 AA cross-sectional structure diagram;

[0019] Figure 5 It is a schematic diagram of the measurement position of the centrifugal compressor of the present invention;

[0020] Figure 6 It is a characteristic diagram of the centrifugal compressor of the present invention. DETAILED DESCRIPTION

[0021] The following is combined with Figure 1 to Figure 6 The principles and features of the present invention are described, and the examples given are only used to explain the present invention and are not used to limit the scope of the present invention. In the following paragraphs, the present invention is described in more detail by way of example with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is an explanation of the embodiments of the present invention based on its overall structure.

[0024] Embodiment 1:

[0025] See also Figure 1 to Figure 6 The present invention discloses a centrifugal compressor test system for a small turbojet engine, comprising a centrifugal compressor, an air intake system, an exhaust system, a lubricating oil system, a cooling water system, a starting system, a data acquisition and processing system, an air intake and exhaust regulation control system, and a safety monitoring system.

[0026] The air intake system is used to introduce outside air into the engine with a centrifugal compressor with minimal flow loss, and calculates the air flow entering the engine by measuring parameters such as the total pressure and static pressure on the flow tube. It includes a dust screen, an air intake duct and a fixed bracket, and has the function of real-time monitoring and filtering the introduced air flow.

[0027] The exhaust system is a test system for discharging the high-pressure gas discharged from the centrifugal compressor through the volute, including the exhaust volute and some mounting parts, and has the function of quickly pressing out the discharged airflow.

[0028] The lubricating oil system is responsible for the lubrication of various components of the test system, including the compressor, transmission device, starting system, etc. The lubricating oil system components include lubricating oil tank, lubricating oil pipeline, oil thermometer, oil pressure regulating valve; it has the function of lubricating and protecting various transmission devices.

[0029] The cooling water system is responsible for cooling the test system, including water supply and drainage pipelines, cooling towers or pools and other facilities; it provides cooling effect for the entire test system.

[0030] The starting system is used to provide speed and torque to the centrifugal compressor and transmit signals to the data processing system, which specifically includes a transmission device, a dynamometer and a controller;

[0031] The data acquisition and processing system is used to sample, process and output the signals of each subsystem; it has the ability to sample and process various types of data, which is conducive to improving the digitization and automation of the entire system.

[0032] The intake and exhaust adjustment control system is responsible for controlling the intake system, exhaust system and air pipelines, communicating with the data acquisition and processing system to complete relevant signal transmission and processing, and realizing automatic control of the intake system and exhaust system.

[0033] The safety monitoring system is used to quickly diagnose faults and issue alarms when abnormalities are found in the test system during operation.

[0034] The data measurements collected in the data acquisition and processing system specifically include: inlet cross-section measurement includes a multi-point total pressure probe for detecting inlet total pressure measurement, a thermocouple for detecting inlet total temperature measurement, and a flow tube for detecting air flow; outlet cross-section measurement includes a rake-shaped total pressure probe that moves radially for detecting outlet total pressure measurement, a multi-point total temperature probe that moves radially for detecting outlet total temperature measurement, and a five-hole pneumatic probe for detecting airflow direction and turbulence parameter measurement; rotor blade rear parameter measurement specifically includes total pressure and total temperature measurement points in front of the stator blade to measure rotor blade rear parameters; wall static pressure measurement specifically includes measuring the total pressure and total temperature measurement points at each measurement section Static pressure holes are opened on the inner and outer walls of the surface, with a hole diameter of 0.5 to 1.0 mm and a center line perpendicular to the airflow direction; static pressure measurement in the flow channel is specifically to measure the static pressure distribution of the airflow in the centrifugal compressor rotor and diffuser flow channel with a single-point static pressure probe; surge detection is specifically to detect the compressor inlet and outlet pulsating pressure with a dynamic test system composed of a dynamic pressure sensor and supporting instruments, and when the measured pressure suddenly changes, it is regarded as an unstable working state; torque and speed measurement is specifically connected to the starting system through a transmission device, the starting system measures the speed and torque of the compressor rotor shaft, the speed is read by a speed sensor, and the starting system and the speed sensor are calibrated with each other.

[0035] The data acquisition and processing system mainly has the following functions:

[0036] 1. Collect, process, display, transmit, print, store and replay measurement parameters;

[0037] 2. Real-time data acquisition and processing can be performed to intuitively display test data in various ways such as digital, virtual instruments and curves;

[0038] 3. It has safety functions such as operation authority management, important parameter over-limit alarm, emergency automatic parking, etc.

[0039] 4. The data recorded by the system can be played back in the form of curves and printed in the form of data points and curves. Customized test reports can be generated and output.

[0040] Embodiment 2:

[0041] See also Figure 2 to Figure 5 Compared with the first embodiment, the present invention provides a centrifugal compressor test system for a small turbojet engine. The present embodiment further includes: a centrifugal compressor, an air intake system, an exhaust system, a lubricating oil system, a cooling water system, a starting system, a data acquisition and processing system, an air intake and exhaust adjustment control system, and a safety monitoring system of the test system are assembled to form a test bench body, specifically including a centrifugal compressor, a mounting bracket, an air intake device, an exhaust volute, a transmission device, a dynamometer, a sensor assembly, and a control terminal.

[0042] By continuously adjusting the relevant parameters in the intake system, exhaust system and other related devices, the actual tested centrifugal compressor characteristic diagram is finally obtained, such as Figure 6 As shown, the characteristic diagram obtained from the centrifugal compressor test is combined with the theoretical calculation results, and continuous corrections are made to finally obtain a centrifugal compressor that can meet the performance requirements.

[0043] The present invention provides a centrifugal compressor test system for a small turbojet engine through improvement, and according to the centrifugal compressor structure commonly used in small turbojet engines, obtains aerodynamic and performance parameters and verifies them with the theoretical calculation results of the compressor, thereby providing a practical basis and reference data for the design of centrifugal compressors and turbojet engines.

[0044] The above shows and describes the basic principles, main features and advantages of the present invention, and the standard parts used in the present invention can be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt the conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here.

[0045] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A centrifugal compressor test system for a small turbojet engine, characterized in that: It includes centrifugal compressor, air intake system, exhaust system, lubricating oil system, cooling water system, starting system, data acquisition and processing system, air intake and exhaust regulation control system and safety monitoring system; Wherein, the air intake system is used to introduce outside air into the engine in the centrifugal compressor with less flow loss, and calculate the air flow entering the engine by measuring the total pressure and static pressure parameters on the flow tube, including a dust screen, an air intake duct and a fixing bracket; The exhaust system is a test system for discharging high-pressure gas discharged from a centrifugal compressor through a volute, and includes an exhaust volute and some mounting parts; The lubricating oil system is used to lubricate the components of the test system. The lubricating oil system components include a lubricating oil tank, lubricating oil pipeline, oil temperature gauge, and oil pressure regulating valve; The cooling water system is used to cool the test system, and specifically includes water supply and drainage pipelines and cooling water towers; The starting system is used to provide speed and torque to the centrifugal compressor and transmit signals to the data processing system, and specifically includes a transmission device, a dynamometer and a controller; The data acquisition and processing system is used to sample, process and output the signals of each subsystem; The intake and exhaust adjustment control system is responsible for controlling the intake system, exhaust system and air pipeline, and communicating with the data acquisition and processing system to complete the relevant signal transmission and processing; The safety monitoring system is used to quickly make fault diagnosis and alarm when an abnormality is found in the test system during operation.

2. According to claim 1, a centrifugal compressor test system for a small turbojet engine is characterized by: The data measurements collected in the data acquisition and processing system specifically include inlet cross-section measurement, outlet cross-section measurement, rotor blade rear parameter measurement, wall static pressure measurement, flow channel static pressure measurement, surge detection, torque and speed measurement, lubricating oil system temperature and pressure measurement and cooling water system temperature measurement, and auxiliary system parameter measurement.

3. A centrifugal compressor test system for a small turbojet engine according to claim 2, characterized in that: The inlet cross-section measurement in the data acquisition and processing system includes a multi-point total pressure probe for detecting the inlet total pressure measurement, a thermocouple for detecting the inlet total temperature measurement, and a flow tube for detecting the air flow; The outlet cross-section measurement in the data acquisition and processing system includes a rake-shaped total pressure probe that moves radially for detecting the outlet total pressure measurement, a multi-point total temperature probe that moves radially for detecting the outlet total temperature measurement, and a five-hole pneumatic probe that is used to detect the airflow direction and turbulence parameter measurement.

4. A centrifugal compressor test system for a small turbojet engine according to claim 3, characterized in that: The rotor blade rear parameter measurement in the data acquisition and processing system is specifically to set total pressure and total temperature measurement points in front of the stator blades to measure the rotor blade rear parameters; The wall static pressure measurement in the data acquisition and processing system is specifically to open static pressure holes on the inner and outer walls of each measurement section, with a hole diameter of 0.5-1.0 mm and a center line perpendicular to the airflow direction.

5. A centrifugal compressor test system for a small turbojet engine according to claim 4, characterized in that: The static pressure measurement in the flow channel in the data acquisition and processing system is specifically to measure the static pressure distribution of the airflow in the centrifugal compressor rotor and diffuser flow channel using a single-point static pressure probe; The surge detection in the data acquisition and processing system is specifically a dynamic test system composed of a dynamic pressure sensor and supporting instruments to detect the compressor inlet and outlet pulsating pressure. When the measured pressure suddenly changes, it is regarded as an unstable working state.

6. A centrifugal compressor test system for a small turbojet engine according to claim 5, characterized in that: The torque and speed measurement in the data acquisition and processing system is specifically connected to the starting system through a transmission device. The starting system measures the speed and torque of the compressor rotor shaft. The speed is read by a speed sensor. The starting system and the speed sensor are mutually verified.

7. A centrifugal compressor test system for a small turbojet engine according to claim 6, characterized in that: The centrifugal compressor, air intake system, exhaust system, lubricating oil system, cooling water system, starting system, data acquisition and processing system, air intake and exhaust adjustment control system and safety monitoring system of the test system are assembled to form the test bench body, which specifically includes a centrifugal compressor, a mounting bracket, an air intake device, an exhaust volute, a transmission device, a dynamometer, a sensor assembly and a control terminal.

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