Gas/dual-fuel engine intake manifold gas injection device

Abstract

The invention provides a gas/dual-fuel engine intake manifold gas injection device. The device comprises an intake manifold, a natural gas injection electromagnetic valve, a gas injection structure and a cylinder cover, wherein the internal structure of the gas injection device is a venturi pipe, and the external frame is provided with a gas supply annular groove; the gas injection structure is mounted in the connection place between the intake manifold and a gas inlet way of the cylinder cover; the gas injection electromagnetic valve is mounted at the top end of the gas injection structure; inner surface gas outlet holes are formed in the throat port of the venturi pipe; an arrangement mode of the inner surface gas outlet holes of the gas injection structure is as follows: the air outlet holes are uniformly distributed along the circular inner surface, and are distributed along the center line of the electromagnetic valve in an axisymmetric manner; and the apertures are increased along with the increment of the distance far from the natural gas injection valve. The device can improve the natural gas and air mixing quality, optimize the engine combustion process and enhance the economy and the emission performance.

Description

Technical field [0001] The invention relates to a gas injection device, in particular to a gas / dual fuel engine intake manifold gas injection device, and belongs to the technical field of engines. Background technique [0002] With the increasingly serious environmental pollution and fossil energy crisis, natural gas has been emphatically studied as a new generation of internal combustion engine alternative fuel. Natural gas has the characteristics of high calorific value, low pollution and abundant reserves. At present, natural gas engines are divided into natural gas single-fuel engines and dual-fuel engines according to the type of fuel. For the supply of natural gas, out-of-cylinder gas supply is mostly used at home and abroad. Natural gas injection valves are installed in the intake manifold or intake manifold. In the intake manifold injection mode, a venturi structure is added to the intake manifold. The gas and air are sucked into the venturi tube by the negative pressure...

AI Technical Summary

Problems solved by technology

At present, natural gas engines are divided into natural gas single-fuel engines and dual-fuel engines according to the type of fuel. As for the supply mode of natural gas, most of them at home and abroad adopt the gas supply mode outside the cylinder at present, and install natural gas injection valves in the intake manifold or intake manifold. For natural gas Intake manifold injection method, a Venturi tube structure is installed on the intake manifold, the gas and air are sucked into the venturi tube by the negative pressure in the cylinder and then enter the cylinder, which can realize the full mixing of natural gas and air, and the mixing uniformity is good, but The intake manifold injection method cannot meet the precise control of the air-fuel ratio of each cylinder, and it is easy to cause uneven air intake of each cylinder, resulting in misfires and other phenomena. In addition, the intake manifold injection method responds slowly to changes in working conditions, resulting in pollutant emissions high volume, high heat load

The natural gas intake manifold injection method can make up for the above problems, but because the intake manifold is closer to the intake valve, the mixing time of natural gas and air is shorter, and the mixing of natural gas and air is uneven. At the same time, because the density of natural gas is lower than that of air, Moreover, the flow velocity of natural gas close to the wall of the intake port decreases due to gas viscosity, resulting in a large amount of natural gas accumulating in the intake port, insufficient intake air, and excessive concentration gradient in the cylinder, resulting in deterioration of combustion, increase in exhaust temperature, and engine emission and performance. economical decline

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