Low-pressure fuel feed system for dimethyl ether and diesel oil being as fuel of engine

Abstract

This invention discloses a low pressure fuel supply system including a start switch, a fuel selection switch, a low pressure oil pump, a pressure pump, electromagnetic control three-way valve, a high pressure oil pump with a sprayer, a pressure meter for testing the oil system, temp feedback dimethyl ether pressure adjustment valve, a diesel single-way valve, a dimethyl box with a low pressure pump in it, a diel tank with a low pressure pump. The pressure at the entrance of the high pressure pump reaches to 1.8MPa-2MPa, idle speed can be stabilized at 6004 / min, the maximum torque increases to 220Nm form 20Nm and the maximum speed reaches to 120Km / h.

Description

1. Technical field [0001] The invention belongs to the technical category of automobiles, internal combustion engines and power machinery, and relates to a supply system for compression ignition engines using dimethyl ether and diesel, in particular to a low-pressure fuel supply system for engines using dimethyl ether or diesel. 2. Background technology [0002] The oil resources in the world can still be exploited for 40 years, but in my country it is only 15-20 years. The research and application of oil alternative fuels is imminent. Diesel engines have high thermal efficiency and good power and economy, but they have high emissions of soot particles and nitrogen oxides, which cause great pollution to the environment. [0003] Dimethyl ether has a high cetane number and contains 34.8% oxygen. When used as an alternative fuel for diesel engines, the NOx emission is only about 30% of that of diesel engines. Smokeless combustion can be achieved in all speed and load ranges, a...

AI Technical Summary

Problems solved by technology

However, dimethyl ether (DME) has a low boiling point (-24.9°C), and is easy to vaporize, causing vapor resistance in the fuel supply system of the engine, which affects the normal operation of the engine.

[0004] Existing low-pressure fuel supply systems for DME engines are difficult to guarantee normal operation under various working conditions

The dimethyl ether demonstration vehicles in Sweden and Japan use nitrogen to pressurize dimethyl ether. A high-pressure container needs to be added to the vehicle, and the system pressure decreases with the consumption of dimethyl ether, which affects the normal operation of the engine.

The AVL LIST Research Institute in Austria adopts the method of elastic membrane, one side of the membrane is liquefied petroleum gas (LPG), and the other side is DME, trying to squeeze DME with a higher saturated vapor pressure of LPG, due to the difference in saturated vapor pressure between the two Smaller, it is difficult to ensure that there is no vapor resistance at parts such as the transportation of dimethyl ether and the fuel injection pump (usually installed on the side of the engine, with high operating temperature); then the method of heating LPG is used to improve the relationship between the two pressure difference, but the deformation of the diaphragm is limited and unsafe, and then the diaphragm is replaced by a piston, and LPG is still used to squeeze and transport DME, which is difficult to solve the leakage of LPG from the piston ring to the DME end

[0005] After the conventional diesel fuel supply system is switched to dimethyl ether, due to the low boiling point of dimethyl ether, it is easy to vaporize and cause vapor resistance, so the engine cannot work normally

The existing patents on the DME fuel supply system do not meet the practical requirements, and the system research and actual assessment of the DME supply system on the engine have not been carried out

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