Piston aircraft engine starting method

Abstract

This invention discloses a method for starting a piston-type aero-engine. The method designs operating procedures for starting the engine under three conditions: cold start, hot start, and rich fuel. It enables rapid engine starting in all three states. This method avoids multiple engine start failures, saves costs, and reduces the need for field support resources.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine starting technology, and particularly relates to a starting method for piston aero-engines. Background Technology

[0002] The piston-type aircraft engine used in the AS700 manned airship encountered starting problems under three different conditions during multiple ground tests in the hangar: cold start, hot start, and rich fuel.

[0003] a) During cold starts, aircraft piston engines are mainly affected by intake air temperature, fuel temperature, and lubricating oil temperature. At lower intake air temperatures, the gas density is higher, resulting in a larger filling volume. At lower fuel temperatures, the viscosity and surface tension of the fuel increase, reducing the random motion of fuel particles and hindering fuel atomization; simultaneously, the average kinetic energy of fuel molecules decreases, reducing the vaporization rate; and at lower lubricating oil temperatures, the viscosity is higher.

[0004] b) When the engine is in a hot state, the engine temperature is too high, and the fuel is easy to evaporate. This will create a high evaporation pressure in the fuel inlet line. When the evaporation pressure is greater than the pressure of the fuel supply system, vapor lock will occur, and the fuel injected by the fuel injector will be too lean.

[0005] c) In a rich fuel environment, excessive fuel may wet the spark plugs, reducing the generation and propagation of sparks; excessive fuel will also hinder air from entering the engine, resulting in insufficient air intake. An excessively high fuel ratio in the mixture will reduce the oxygen content and affect the combustion process.

[0006] When the engine is cold-started, hot-started, or fuel-rich, it is difficult to start the engine using existing engine starting methods. Summary of the Invention

[0007] Purpose of the invention

[0008] To address the problem of difficulty in starting existing engines under cold, hot, and rich fuel conditions, this invention provides a starting method for piston-type aero engines.

[0009] Invention Technology Solutions

[0010] Starting methods for piston-type aircraft engines include starting methods under cold conditions, starting methods under warm conditions, and starting methods under rich fuel conditions;

[0011] The starting method for a cold engine includes the following steps:

[0012] a) Push the mixture control lever and the throttle control lever to the rich fuel position and the maximum throttle position respectively, turn on the electric fuel pump, and wait until the fuel flow is displayed and stabilized;

[0013] b) Pull the mixture ratio lever back to the idle off position, and pull the throttle lever back to the idle off position;

[0014] c) Push the throttle lever to the 1 / 4 position;

[0015] d) Turn the ignition switch knob to the "start" position. After the engine starts, release the ignition switch and it will automatically switch to the "BOTH" position.

[0016] e) Push the mixing ratio lever to "full hydration" and engage the throttle lever accordingly;

[0017] f) Warm up the engine at the set speed;

[0018] The starting procedure for a warm engine includes the following steps:

[0019] a) Push the mixture control lever and the throttle control lever to the rich fuel position and the maximum throttle position respectively, turn on the electric fuel pump, and wait until the fuel flow is displayed and stabilized;

[0020] b) Pull the mixture ratio lever back to the idle off position, and pull the throttle lever back to the idle off position;

[0021] c) Push the throttle lever to the 1 / 4 position;

[0022] d) Turn on the electric fuel pump;

[0023] e) Turn the ignition switch knob to the "start" position. After the engine starts, release the ignition switch and it will automatically jump to the "BOTH" position.

[0024] f) Push the mixing ratio lever to "full grease" and operate the throttle lever accordingly;

[0025] g) After the engine starts successfully and stabilizes, turn off the electric fuel pump.

[0026] h) Warm up the engine at the set speed;

[0027] The starting procedure under rich oil conditions includes the following steps:

[0028] a) Push the throttle lever forward to the maximum position;

[0029] b) Turn the ignition switch knob to the "start" position, release the throttle during the starting process, and after the engine starts, release the ignition switch to automatically switch to the "BOTH" position;

[0030] c) Push the mixing ratio lever to "full oil" and operate the throttle lever accordingly;

[0031] d) Keep the engine at the set speed to warm up.

[0032] Preferably, in step a) of the starting method under cold conditions, the mixture ratio and throttle lever are fully opened when pumping oil.

[0033] Preferably, in steps e) of the starting method under cold conditions, steps e) of the starting method under hot conditions, and steps c) of the starting method under rich fuel conditions, when the ambient temperature is -5℃ to -15℃, the throttle lever and the mixture lever need to work together to find the optimal ignition point.

[0034] Preferably, in step f) of the starting method under cold conditions, the speed is set to 1100 r / min to 1200 r / min.

[0035] Preferably, in step a) of the starting method under warm conditions, the mixture ratio and throttle lever are fully opened when pumping oil.

[0036] Preferably, in step h) of the starting method under warm conditions, the speed is set to 1100 r / min to 1200 r / min.

[0037] Preferably, in steps e), f), and c) of the starting method under cold conditions, the process of pushing the mixing ratio lever to "full oil rich" is carried out at a constant speed and is completed in about 10 seconds.

[0038] Preferably, in step d) of the starting method under oil-rich conditions, the speed is set to 1100 r / min to 1200 r / min.

[0039] Preferably, in the starting method under rich fuel conditions, step b) involves releasing the throttle during the starting process at a constant speed, which takes about 3 seconds.

[0040] Advantages of this invention: This method can avoid multiple engine start-up failures, save costs, and reduce the demand for field support resources. Detailed Implementation

[0041] The present invention is achieved through the following technical solution.

[0042] Starting methods for piston-type aircraft engines include starting methods under cold conditions, starting methods under warm conditions, and starting methods under rich fuel conditions.

[0043] Starting method when the engine is cold:

[0044] a) Push the air-fuel mixture lever and throttle lever to the rich and maximum throttle positions, respectively, and turn on the electric fuel pump until the fuel flow is displayed and stabilized. (When pumping fuel, be sure to fully open the air-fuel mixture lever and throttle lever to allow better fuel and air to enter the engine.)

[0045] b) Pull the mixture ratio back to the idle cut-off position, and pull the throttle lever back to the idle cut-off position;

[0046] c) Push the throttle lever to the 1 / 4 position;

[0047] d) After the engine starts when the ignition switch knob is turned to the "start" position (within 10 seconds), release the ignition switch and it will automatically jump to the "BOTH" position.

[0048] e) Slowly (complete this in about 10 seconds) push the mixture lever to "full fuel rich" and coordinate with the throttle lever to ensure stable engine starting; (low ambient temperature will affect fuel atomization quality and engine starting will be unstable, requiring the throttle lever and mixture lever to work together to find the optimal kick point)

[0049] f) Maintain engine warm-up at 1100-1200 rpm. (Due to ambient temperature, lubricating oil temperature rises slowly, so increase engine speed by 100 rpm.)

[0050] Starting method when the engine is warm:

[0051] a) Push the air-fuel mixture lever and throttle lever to the rich and maximum throttle positions, respectively, and turn on the electric fuel pump until the fuel flow is displayed and stabilized. (When pumping fuel, be sure to fully open the air-fuel mixture lever and throttle lever to allow better fuel and air to enter the engine.)

[0052] b) Pull the mixture ratio back to the idle cut-off position, and pull the throttle lever back to the idle cut-off position;

[0053] c) Push the throttle lever to the 1 / 4 position;

[0054] d) Turn on the electric fuel pump

[0055] e) After the engine starts when the ignition switch knob is turned to the "start" position (within 10 seconds), release the ignition switch and it will automatically jump to the "BOTH" position.

[0056] f) Slowly push the mixture lever to "full fuel rich" (complete in about 10 seconds) and coordinate with the throttle lever to ensure stable engine starting; (low ambient temperature will affect fuel atomization quality and engine starting will be unstable, requiring the throttle lever and mixture lever to work together to find the optimal kick point)

[0057] g) After the engine starts successfully and stabilizes, turn off the electric fuel pump.

[0058] h) Maintain the engine at 1100-1200 r / min to warm up.

[0059] Starting method under rich oil conditions:

[0060] a) Push the throttle lever forward to the maximum position;

[0061] b) Turn the ignition switch knob to the "start" position (no more than 10 seconds) and slowly release the accelerator during the starting process (complete in about 3 seconds). After the engine starts, release the ignition switch and it will automatically jump to the "BOTH" position.

[0062] c) Slowly (complete this in about 10 seconds) push the mixture lever to "full fuel rich" and coordinate with the throttle lever to ensure stable engine starting; (low ambient temperature will affect fuel atomization quality and engine starting will be unstable, requiring the throttle lever and mixture lever to work together to find the optimal kick point)

[0063] d) Maintain the engine speed at 1100-1200 r / min for warm-up.

[0064] The scope of protection of this invention is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its scope. If such modifications and variations fall within the scope of the claims of this invention and their equivalents, then the intent of this invention also includes these modifications and variations.

Claims

1. A method for starting a piston-type aircraft engine, characterized in that, This includes starting methods for cold engines, starting methods for warm engines, and starting methods for engines with rich fuel. The starting method for a cold engine includes the following steps: a) Push the mixture control lever and the throttle control lever to the rich fuel position and the maximum throttle position respectively, turn on the electric fuel pump, and wait until the fuel flow is displayed and stabilized; b) Pull the mixture ratio lever back to the idle off position, and pull the throttle lever back to the idle off position; c) Push the throttle lever to the 1 / 4 position; d) Turn the ignition switch knob to the "start" position. After the engine starts, release the ignition switch and it will automatically switch to the "BOTH" position. e) Push the mixture control lever to "full fuel" and engage the throttle control lever accordingly; f) Warm up the engine at the set speed; The starting procedure for a warm engine includes the following steps: a) Push the mixture control lever and the throttle control lever to the rich fuel position and the maximum throttle position respectively, turn on the electric fuel pump, and wait until the fuel flow is displayed and stabilized; b) Pull the mixture ratio lever back to the idle off position, and pull the throttle lever back to the idle off position; c) Push the throttle lever to the 1 / 4 position; d) Turn on the electric fuel pump; e) Turn the ignition switch knob to the "start" position. After the engine starts, release the ignition switch and it will automatically jump to the "BOTH" position. f) Push the mixture control lever to "full oil" and operate the throttle control lever accordingly; g) After the engine has started successfully and stabilized, turn off the electric fuel pump; h) Warm up the engine at the set speed; The starting procedure under rich oil conditions includes the following steps: a) Push the throttle lever forward to the maximum position; b) Turn the ignition switch knob to the "start" position, release the accelerator during the starting process, and after the engine starts, release the ignition switch to automatically switch to the "BOTH" position; c) Push the mixture control lever to "full oil" and operate the throttle control lever accordingly; d) Keep the engine at the set speed to warm up.

2. The piston-type aircraft engine starting method as described in claim 1, characterized in that, In the starting procedure under cold conditions, step a) involves fully opening the mixture control lever and throttle lever while pumping oil.

3. The starting method for a piston-type aircraft engine as described in claim 1, characterized in that, When the ambient temperature is between -5℃ and -15℃, the throttle lever and the mixture control lever need to work together to find the optimal starting point for starting the engine in the following steps: (e) for starting the engine when it is cold, (f) for starting the engine when it is hot, and (c) for starting the engine when it is rich in fuel.

4. The piston-type aircraft engine starting method as described in claim 1, characterized in that, In step f) of the cold start method, the engine speed is set to 1100 r / min ~ 1200 r / min.

5. The piston-type aircraft engine starting method as described in claim 1, characterized in that, In step a) of starting the engine when it is warm, the mixture ratio and throttle lever are fully open when pumping oil.

6. The starting method for a piston-type aircraft engine as described in claim 1, characterized in that, In step h) of the starting method under warm conditions, the speed is set to 1100 r / min ~ 1200 r / min.

7. The starting method for a piston-type aircraft engine as described in claim 1, characterized in that, In steps e), f), and c), the mixture control lever is pushed to "full fuel" in the cold start condition and the process is carried out at a constant speed, taking about 10 seconds.

8. The method for starting a piston-type aircraft engine as described in claim 1, characterized in that, In step d) of the starting method under rich oil conditions, the speed is set to 1100 r / min ~ 1200 r / min.

9. The starting method for a piston-type aircraft engine as described in claim 1, characterized in that, Steps for starting under rich fuel conditions (b) During the starting process, the throttle should be released at a constant speed and completed in about 3 seconds.