Self-sufficient type internal combustion engine gas fuel supply system and gas packet pressure control method

Abstract

The invention discloses a self-sufficient type internal combustion engine gas fuel supply system and a gas packet pressure control method. The system comprises an LNG tank, an LNG supply pump, an LNG vaporizer, a gas pocket and an NG injection valve. During work, liquefied natural gas stored in the LNG tank flows to the shell pass of the LNG vaporizer under the action of the LNG supply pump, absorbs heat on the shell pass and becomes gaseous natural gas to be stored in the gas pocket. The NG injection valve is used for injecting a quantitative amount of gas fuel to a gas inflow channel. Heat-transfer mediums circulated in the medium-high temperature segment in a cooling system flow into the tube pass of the LNG vaporizer through a heat transfer medium three-way valve and flow back to a low temperature segment of the cooling system after releasing heat, the heat transfer mediums flow into a cylinder sleeve of an internal combustion engine to absorb heat again, and circulation is unceasingly performed in this way. According to the method, a fuzzy controller, a Smith predictor and an artificial immunity controller, the LNG supply flow and the heat transfer medium flow can be dynamically optimized well according to gas packet pressure and NG flow changes, the gas pocket pressure can be stabilized within a given area, and influences caused by nonlinearity and time lag of the system are well eliminated.

Description

technical field [0001] The invention relates to a gas fuel supply system of a self-contained internal combustion engine and a gas bag pressure control method, belonging to the field of internal combustion engines. Background technique [0002] Compared with traditional petroleum fuels, liquefied natural gas (LNG) has the characteristics of low carbon, high efficiency, high quality and cleanliness, and is an ideal alternative fuel for internal combustion engines. Because LNG is stored and transported at a low temperature of -163°C under normal pressure, in practical applications, it can be pre-vaporized into gaseous fuel (NG) before it can be burned for work. However, compared with the gas stations on the market, the gas stations on the market are far less perfect in terms of quantity and regional distribution, which greatly limits the use of LNG on long-distance vehicles (ships, intercity buses and trucks). . In order to break through the shortcomings of few and uneven dis...

AI Technical Summary

Problems solved by technology

However, the classic control is greatly affected by the performance of discrete devices, and the subsystems in the system have a great influence on each other. The automation level is not high, the control effect is not very ideal, and it is prone to failure, which is not conducive to the long-term safe and efficient operation of the system.

Modern control is suitable for control objects with linear and precise mathematical models, but it is too difficult to establish precise mathematical models for control systems such as air bag pressure, so it is not an ideal choice

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