Natural gas engine transient state compensation control system and method

Abstract

The invention discloses a natural gas engine transient state compensation control system and method. The control system comprises a throttle position sensor and an inlet manifold absolute pressure sensor, wherein the throttle position sensor and the manifold absolute pressure sensor are electrically connected with an engine ECU. The engine ECU comprises a TPS differential compensation module, an MAP differential compensation module and a compensation amount determination module. The control method comprises the steps that compensation is conducted on the pressurized air amount through the TPSdifferential compensation module and the MAP differential compensation module based on parameters which are set in advance and signals transmitted by the throttle position sensor and the manifold absolute pressure sensor, so that TPS pressurized air compensation flow and MAP pressurized air compensation flow are obtained; and verification is conducted on the TPS pressurized air compensation flow and the MAP pressurized air compensation flow through the compensation amount determination module, and final pressurized air compensation flow and the fuel injection amount are determined. According to the natural gas engine transient state compensation control system and method, the fuel or pressurized air amount requirement generated when the engine load changes in the transient state is met through the transient state compensation function; engine performance is improved; and transient state responsiveness and tail gas emission performance are improved.

Description

technical field [0001] The invention belongs to the technical field of natural gas engine control, and in particular relates to a natural gas engine transient compensation control system and control method capable of satisfying the demand of fuel or pressurized air flow due to engine load changes in transient state. Background technique [0002] The natural gas engine controls the supercharged air through the electronic throttle, and the supercharged air and the natural gas injected by the fuel control valve form a mixed gas through the mixing device, which is distributed to the cylinder through the intake manifold to burn and perform work. When the engine is working in a steady state, the air flow through the electronic throttle is equal to the air flow flowing into the intake valve. However, when the engine is working in a transient (rapid acceleration and deceleration) condition, the When the opening of the electronic throttle changes rapidly, the flow of supercharged air...

AI Technical Summary

Problems solved by technology

When the engine is working in a steady state, the air flow through the electronic throttle is equal to the air flow flowing into the intake valve. However, when the engine is working in a transient (rapid acceleration and deceleration) condition, the When the opening of the electronic throttle changes rapidly, the flow of supercharged air entering the cylinder through the intake manifold will increase or decrease suddenly, and the flow of supercharged air in the intake manifold will be positive due to the throttling effect of the electronic throttle. The reduction or reverse increase is more serious, resulting in the fuel concentration of the engine being too lean during rapid acceleration, which cannot meet the fuel demand of the engine under normal load under transient conditions, and eventually causes problems such as insufficient power and poor transient response of the engine ; During rapid deceleration, the fuel concentration will be too rich, which cannot meet the fuel demand of the engine under normal load under transient conditions, and ultimately make the transient response of the engine worse and exhaust emissions worse

[0003] At present, most natural gas engines meet the fuel demand of the engine's normal load and improve exhaust emissions by correcting the air-fuel ratio and redoxing the exhaust gas. not effectively

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