A windmill process starting method for ground bench test of an aero-engine core engine

Abstract

The application belongs to the technical field of aero-engine core engine ground test running, and particularly relates to a windmill process starting method for aero-engine core engine ground test running, which comprises the following steps: generating high pressure at the inlet of the core engine by using a test bed to drive the core engine to rotate; when the rotating speed of the core engine reaches the ignition rotating speed, oil is supplied to the combustion chamber to ignite; if the core engine fails to be ignited, the oil supply to the combustion chamber is stopped, the high pressure at the inlet of the core engine is maintained for 3 minutes, the pressure at the inlet of the core engine is reduced to the ambient pressure under the condition that no obvious fuel blowing out occurs at the outlet of the core engine, and the core engine is started again; if the core engine is successfully ignited: when the core engine is in suspension, the pressure at the inlet of the core engine is increased; when the core engine stalls, the accelerating oil supply amount is reduced; when the exhaust temperature of the core engine is too high, the accelerating oil supply amount is reduced; the remaining power of the turbine is used to drive the compressor to accelerate to the slow-speed rotating speed, and the starting of the core engine is completed.

Description

Technical Field

[0001] This application belongs to the technical field of ground test of aero-engine core engine, specifically relating to a windmill process start-up method for ground test of aero-engine core engine. Background Technology

[0002] The ground test bench for the aero-engine core engine is designed with a test bench, including a high-pressure gas source, an electric heater, and a pressure regulator. The high-pressure gas source and the pressure regulator are connected by a pipeline, on which an electric heater and a flow control valve are sequentially installed. An venting pipeline is connected between the electric heater and the flow control valve, and an venting valve is installed on the venting pipeline. The pressure regulator is connected to the core engine inlet. By controlling the electric heater, the flow control valve, and the venting valve, the required temperature, pressure, and flow rate are generated to simulate the inlet conditions of the core engine and to conduct the test of the core engine.

[0003] Ground test of an aero-engine core involves starting the core. Currently, a starter motor is mainly used for starting. The specific process is as follows:

[0004] The first stage involves using a starter to drive the core machine to rotate, which mainly refers to the rotation of rotor components such as the compressor.

[0005] In the second stage, when the core engine reaches the ignition speed, fuel is supplied to the combustion chamber for ignition, and the compressor rotates under the drive of the starter and its turbine.

[0006] In the third stage, when the core engine reaches the predetermined speed, the starter is disengaged, and the compressor accelerates to idle speed under the power of the remaining turbine, thus completing the start-up of the core engine.

[0007] The ground test of the aero-engine core engine using a starter motor for assisted starting has the following drawbacks:

[0008] 1) The starter motor needs to be specially developed and configured with corresponding power according to the rotational inertia of the compressor, resulting in poor versatility;

[0009] 2) The application of starter motors requires the configuration of corresponding starting conditions, such as fuel conditions, power supply conditions, and air supply conditions, resulting in higher operating costs;

[0010] 3) The application of starters requires the configuration of corresponding operating conditions, such as temperature and humidity conditions. The technical requirements are high, and it is difficult to control them precisely, which can easily lead to the failure to start the core machine. There are also requirements for use and life management, resulting in high maintenance costs.

[0011] This application is made in view of the aforementioned technical deficiencies.

[0012] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this invention, and it does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0013] The purpose of this application is to provide a windmill process start-up method for ground test of aero-engine core, in order to overcome or mitigate at least one of the known technical defects.

[0014] The technical solution of this application is:

[0015] A method for starting the windmill process during ground test of an aero-engine core engine includes:

[0016] The test bench generates high pressure at the inlet of the core machine to establish a pressure difference between the inlet and outlet of the core machine, which drives the core machine to rotate.

[0017] When the core engine reaches the ignition speed, fuel is supplied to the combustion chamber for ignition.

[0018] If the core engine fails to ignite, stop supplying fuel to the combustion chamber and maintain the core engine intake pressure for 3 minutes. If there is no obvious fuel blowing out of the core engine outlet, reduce the pressure at the core engine inlet to ambient pressure, adjust the ignition speed, and then start the engine.

[0019] If the core engine ignition is successful:

[0020] When core engine suspension occurs, increase the pressure at the core engine inlet;

[0021] When the core engine stalls, reduce the acceleration fuel supply.

[0022] If the core engine exhaust temperature exceeds the limit, reduce the acceleration oil supply.

[0023] The remaining power of the turbine is used to accelerate the core engine to idle speed, thus starting the core engine.

[0024] According to at least one embodiment of this application, the windmill process start-up method for ground test of the aero-engine core engine described above further includes:

[0025] The test bench generates high pressure at the inlet of the core machine to establish a pressure difference between the inlet and outlet of the core machine, which drives the core machine to rotate.

[0026] After the core machine speed stabilizes, the stable core machine speed is recorded for 3 minutes.

[0027] Change the core engine intake pressure conditions and record the corresponding stable speed of the core engine;

[0028] The relationship between high pressure at the inlet of the core engine and stable speed is established.

[0029] According to at least one embodiment of this application, the windmill process start-up method for ground test of the aero-engine core engine described above further includes:

[0030] The relationship between compressor power, turbine power and compressor speed under different pressure differences at the inlet and outlet of the core engine is established. The compressor speed when the turbine power is greater than the compressor power is taken as the ignition speed. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the test stand for ground testing of the core engine of an aero-engine.

[0032] Figure 2 This is a schematic diagram comparing the turbine power and compressor power when starting with the assistance of a starter motor, as provided in the embodiments of this application, with the core engine inlet pressure of 150 kPa.

[0033] Figure 3 This is a schematic diagram of the windmill process start-up method for ground test of the aero-engine core machine provided in the embodiments of this application.

[0034] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual size of the product. Furthermore, the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Detailed Implementation

[0035] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0036] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0037] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection 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 an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0038] The test stand for ground testing of aero-engine core engines can generate high pressure at the core engine inlet. Due to the throttling effect of the core engine itself, a pressure difference can be formed at the core engine inlet and outlet, thereby generating ram pressure, which can drive the core engine to rotate. When the core engine rotates to a certain speed, ignition is performed to accelerate it to idle speed, thus completing the start-up of the core engine. Therefore, this application provides a windmill process start-up method for ground testing of aero-engine core engines. The following is in conjunction with the appendix. Figures 1 to 3 To be further explained in detail.

[0039] The ground-based start-up process of an aero-engine core engine can be roughly divided into three stages:

[0040] During the wind turbine operation phase, a high pressure is generated at the core machine inlet using a test bench to drive the core machine to rotate. At this time, the compressor is in an expansion state with a pressure ratio of less than 1.

[0041] During the ignition phase, when the core engine rotates to the ignition speed, fuel is supplied to the combustion chamber for ignition. The compressor rotates under the action of ram and driven by the turbine. In the very short time after ignition, the gas flows into the turbine rapidly to expand and do work. At the same time, the temperature rises, which leads to a decrease in flow rate, causing the compressor flow rate to decrease rapidly and the compressor pressure ratio to become greater than 1.

[0042] During the acceleration phase, the remaining power of the turbine is used to drive the compressor to accelerate to idle speed, thus completing the start-up of the core engine.

[0043] The ignition speed is determined based on the fact that the remaining power of the turbine after ignition is greater than 0, that is, the power output of the turbine is greater than the power required for the compressor to rotate, so that after ignition, the compressor can continue to accelerate to idle speed and complete the start-up of the core engine.

[0044] Increasing the core engine inlet pressure greatly helps improve the turbine's work capacity. A comparison is made between starting turbine and compressor power using a starter motor-assisted method and the result at a core engine inlet pressure of 150 kPa. Figure 2 As shown, the increased inlet pressure of the core engine greatly improves the turbine's work capacity. Even at a relatively low compressor speed, the turbine's residual power is greater than zero. When starting the aero-engine core engine using the ground trolley process, the ignition speed can be referenced to the ignition speed when starting with the starter motor assistance.

[0045] In order to accurately determine the ignition speed required for the ground typhoon process of the aero-engine core, the corresponding relationship between compressor power, turbine power and compressor speed under different high pressures generated at the core inlet can be constructed through experiments or simulations. The compressor speed when the turbine power is greater than the compressor power is taken as the ignition speed.

[0046] Before starting the ground scramble process of the aero-engine core engine, it is advisable to determine the stable operating speed of the compressor corresponding to the high pressure generated at the core engine inlet. This will allow for the selection of appropriate high pressure based on the ignition speed during the ground scramble process. The specific process is as follows:

[0047] The test bench generates high pressure at the core engine inlet, which drives the compressor to rotate. The core engine inlet temperature does not exceed 30°C.

[0048] After the compressor speed stabilizes, the rate of increase in speed is ≤100 r / min for 3 minutes, and the stable speed of the compressor is recorded.

[0049] Change the high pressure generated at the core engine inlet, repeat the above process, and record the stable speed of the corresponding compressor.

[0050] The relationship between the high pressure at the core engine inlet and the stable compressor speed is as follows:

[0051] Serial Number 1 2 3 4 5 6 Core engine import pressure P1 P2 P3 P4 P5 P6 compressor stable speed N1 N2 N3 N4 N5 N6

[0052] The windmill start-up method for ground test of aero-engine core engine, such as... Figure 3 As shown, it includes:

[0053] The test bench generates high pressure at the core engine inlet to drive the core engine to rotate. The temperature at the core engine inlet does not exceed 30°C to ensure stable air intake conditions.

[0054] When the core engine reaches the ignition speed, fuel is supplied to the combustion chamber for ignition.

[0055] If the core engine fails to ignite, stop supplying fuel to the combustion chamber and maintain high pressure at the core engine inlet for 3 minutes. If there is no obvious fuel blowout from the core engine outlet, the remaining fuel has been blown away and the cooling has been accelerated. Then, reduce the pressure at the core engine inlet to ambient pressure to create favorable conditions for the next core engine start-up. When starting the core engine again, the high pressure at the core engine inlet, ignition speed, and fuel supply can be adjusted appropriately.

[0056] If the core engine ignites successfully, maintain the high-pressure condition at the core engine inlet and observe for any abnormalities, including:

[0057] When compressor hang occurs, that is, when the compressor speed cannot increase, increase the pressure at the core engine inlet;

[0058] When the compressor stalls, that is, when the compressor surges, reduce the acceleration fuel supply, and in severe cases, terminate the start-up.

[0059] If the exhaust temperature of the core engine exceeds the limit, the fuel supply to the engine will be reduced, and in severe cases, the start-up will be terminated.

[0060] The remaining power of the turbine is used to drive the compressor to accelerate to idle speed, thus starting the core engine.

[0061] The windmill process starting method for ground test of aero-engine core engine disclosed in the above embodiments can be understood by those skilled in the art as it can be completed with the aid of a test stand, without the need for a starter motor. This avoids the problems caused by using a starter motor for starting. By utilizing the high pressure generated at the core engine inlet on the test stand, the core engine can be started efficiently through appropriate adjustment and control.

[0062] The aforementioned windmill-based start-up method for ground test of aero-engine core components can also be applied to the start-up of the entire aero-engine.

[0063] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0064] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for starting the windmill process during ground test of an aero-engine core engine, characterized in that, include: The relationship between compressor power, turbine power and compressor speed under different pressure differences at the inlet and outlet of the core engine is established. The compressor speed when the turbine power is greater than the compressor power is used as the ignition speed. The test bench generates high pressure at the inlet of the core machine to establish a pressure difference between the inlet and outlet of the core machine, which drives the core machine to rotate. When the core engine reaches the ignition speed, fuel is supplied to the combustion chamber for ignition. If the core engine fails to ignite, stop supplying fuel to the combustion chamber and maintain the core engine intake pressure for 3 minutes. If there is no obvious fuel blowing out of the core engine outlet, reduce the pressure at the core engine inlet to ambient pressure, adjust the ignition speed, and then start the engine. If the core engine ignition is successful: When core engine suspension occurs, increase the pressure at the core engine inlet; When the core engine stalls, reduce the acceleration fuel supply. If the core engine exhaust temperature exceeds the limit, reduce the acceleration oil supply. The remaining power of the turbine is used to accelerate the core engine to idle speed, thus starting the core engine.

2. The windmill process start-up method for ground test of aero-engine core engine according to claim 1, characterized in that, Also includes: After the core machine speed stabilizes, the stable core machine speed is recorded for 3 minutes. Change the core engine intake pressure conditions and record the corresponding stable speed of the core engine; The relationship between high pressure at the inlet of the core engine and stable speed is established.

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