Device and method for reducing heat load of natural gas engine by alcohol doping

Abstract

The invention discloses a device and a method for reducing heat load of a natural gas engine by alcohol doping. The device and the method are characterized by carrying out closed-loop control on the injection quantity of natural gas and alcohol fuels by using an actual excess air coefficient measured by a wide-range oxygen sensor, so that the engine stably runs under a target excess air coefficient and any alcohol fuel mixing proportion, thereby reducing the heat load of the natural gas engine by the alcohol doping, creating conditions for further improving the compression ratio of the engine,further increasing the heat efficiency of the natural gas engine and reducing the hydrocarbon emission.

Description

technical field [0001] The invention belongs to the technical field of engine alternative fuels, and in particular relates to a control system for reducing heat load of a natural gas engine by blending alcohol. Background technique [0002] The increasingly severe energy and environmental problems have prompted the continuous advancement of theories and technologies for energy-saving and emission-reduction of internal combustion engines. Efficiency, cleanliness and energy saving are the development goals of advanced internal combustion engines. Using low-carbon fuels combined with advanced combustion technology is one of the important ways to realize energy saving and emission reduction of internal combustion engines. Natural gas and alcohol fuels are two low-carbon fuels with great development potential. Natural gas is widely used in ignition and compression ignition engines due to its large reserves, high octane number, low particulate matter emissions, and low price. ...

AI Technical Summary

Problems solved by technology

[0003] Natural gas engines face the following problems: first, natural gas is a gaseous fuel with low density, and the intake port injection will occupy part of the volume of fresh air, resulting in a decrease in engine charge and power reduction; second, the flame propagation speed of natural gas is small, and the ignition energy Higher, resulting in a longer period of rapid combustion, lower combustion equipotentiality, and lower thermal efficiency of the engine; in addition, in the face of increasingly stringent emission regulations, most natural gas engines use the equivalent ratio combustion method, in which the mixture gas The concentration is higher, the combustion temperature in the engine cylinder is higher, resulting in higher heat load and exhaust temperature in the cylinder, and the effective thermal efficiency of the engine is reduced

[0005] Although natural gas and alcohol fuels (methanol, ethanol, and n-butanol) are complementary in combustion characteristics, it is difficult to flexibly adjust the ECU control strategy according to the different alcohol fuels (methanol, ethanol, n-butanol) injected, At present, natural gas engines mainly use methanol blending (for example, 201410498626.X), and the control strategy for blending methanol uses engine temperature as the feedback signal, and there is no precise control of the ratio of methanol blending, which cannot guarantee the stable operation of the engine

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