Natural gas engine waste gas bypass type booster control system and method

Abstract

The invention provides a natural gas engine waste gas bypass type booster control system which comprises a compressed air storage bottle, a pressure reducer, a booster control valve, a waste gas bypass pressure sensor, an engine control unit, a boosting pressure sensor, a booster waste gas bypass control membrane valve and a booster. The booster comprises a booster waste gas bypass valve, a booster turbine and a booster compressor. The engine control unit controls opening of an electromagnetic valve on the basis of pressure data collected by the boosting pressure sensor and the waste gas bypass pressure sensor, therefore, outlet air pressure of the booster control valve is controlled, and opening of the booster waste gas bypass valve is controlled. The invention further provides a naturalgas engine waste gas bypass type booster control method. An air inlet throttle loss can be reduced, exhaust back pressure can also be reduced, the charging efficiency is improved, and finally fuel economy is improved.

Description

technical field [0001] The invention belongs to the technical field of engine control systems, and in particular relates to a natural gas engine waste gas bypass supercharger control system and a method thereof. Background technique [0002] At present, the natural gas engines used in commercial vehicles are all equipped with turbochargers to increase the air intake per unit volume of the engine and increase the power density of the engine. However, in order to keep the boost pressure of the supercharger from exceeding the demand value of the engine, or to prevent the compressor of the supercharger from entering the low-efficiency working area, a wastegate valve is installed on the turbine side of the supercharger. After the pressure exceeds a certain value, the wastegate valve is pushed open, and part of the exhaust gas is directly discharged to the supercharger without passing through the turbine, so that the amount of exhaust gas used to drive the turbine to do work is re...

AI Technical Summary

Problems solved by technology

For the natural gas engine equipped with a turbocharger equipped with a commercial vehicle, since the throttle valve is used to regulate the load, the pressure of the intake manifold is reduced by throttling the throttle valve, thereby reducing the intake air volume of the engine. This reduces the engine load; for medium load conditions, the turbocharger has started to work, but the boost pressure is much higher than the intake manifold pressure required by the current load, and the intake manifold pressure has to be controlled by closing the throttle valve , the throttling of the intake air by the throttle valve increases the throttling loss of the intake air and reduces the fuel economy; at the same time, due to the work of the supercharger, the exhaust gas in front of the turbine is pressurized, resulting in a decrease in the charging efficiency of the engine. The increase in residual exhaust gas reduces combustion efficiency and directly leads to a decrease in fuel economy;

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