Gas engine operation method under low gas pressure condition

Abstract

The invention discloses a gas engine operation method under the low gas pressure condition. The method comprises following steps that an engine runs; according to the rotating speed of the engine, the maximum injection pulse width allowable under the current condition, driving torque needed by a driver, the maximum gas flow allowable under the current condition and the maximum air inlet amount A allowable under the current condition are calculated according to the rotating speed of the engine; according to the calculated driving torque needed by the driver, an air inlet amount B is obtained through calculation; the maximum air inlet amount A allowable under the current condition and the air inlet amount B are compared, and through the small value of the maximum air inlet amount A and the air inlet amount B, an air inlet amount C is obtained; and according to the air inlet amount C, a needed gas flow and a needed injection pulse width are calculated. When the current gas pressure is low, through the slow control over the air inlet amount, the torque output of the engine is slowly reduced; and through active adjusting, the air amount is reduced so as to reduce the torque output, the condition that the torque is suddenly reduced is prevented from appearing, vehicle flameout and shaking are avoided, and safe and stable driving is ensured.

Description

technical field [0001] The invention relates to the technical field of a gas engine, in particular to a method for operating a gas engine. Background technique [0002] At present, there are more and more engines using LNG as fuel, but at low temperature, especially after starting at low temperature in cold regions, the water temperature of the engine is low, the vaporization of LNG is not good, or the heat exchange device of the LNG tank is not good, which causes the LNG to burn after heat exchange. The pressure cannot be established; and in some mountainous areas, when climbing a slope, the gas demand increases in a short period of time due to the rapid gas pedal, and the gas pressure drops, and the pressure recovers after the gas pedal is released. In these cases, due to the low gas pressure, the engine will report an error and limit the torque. Even after the pressure is restored, the engine must be turned off before the ignition key can run normally. [0003] The reaso...

AI Technical Summary

Problems solved by technology

[0004] like figure 2 As shown in the working principle diagram of gas engine operation in the prior art, the ECU judges the required injection pulse width and the allowable injection pulse width in the current situation. When the required injection pulse width is greater than the allowable injection pulse width in the current situation, Engine error, limited torque operation

The engine can only passively limit the torque to

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