Combined non-pressurized fuel oil and pressurized fuel gas dual piezoelectric mixed fuel injection device

Abstract

The invention aims at providing a combined non-pressurized fuel oil and pressurized fuel gas dual piezoelectric mixed fuel injection device.The mixed fuel injection device comprises a fuel gas pressurizing part, a dual piezoelectric control part, a nozzle part and the like.A pressurizing electromagnetic valve is utilized for controlling motion of a pressurizing piston to achieve fuel gas pressurization, two piezoelectric elements are utilized for controlling a fuel gas nozzle to inject fuel gas and controlling a fuel oil nozzle to inject fuel oil respectively, and three working modes of pure fuel oil injection, fuel oil and non-pressurized fuel gas dual-fuel injection and fuel oil and pressurized-gas dual-fuel injection can be achieved.The fuel gas pressurizing part controls fuel gas pressurization, the fuel gas pressurization timing is controllable, switching of fuel gas pressurizing injection and fuel gas non-pressurizing injection can be achieved rapidly, and the different requirements of different powers of a dual-fuel engine on fuel gas injection pressure are met.

Description

technical field [0001] The invention relates to a fuel injection device, in particular to a dual-fuel engine fuel injection device. Background technique [0002] The development of alternative fuels for engines is one of the very effective means to solve the problems of energy shortage and environmental pollution. Due to the advantages of abundant reserves, low price and low pollution emissions, gaseous fuel has become an alternative fuel for engines with good development prospects. Although the gas engine using only one gas fuel has clean emissions, the gas fuel used has low energy density, high fuel consumption, and limited use direction; while the dual-fuel engine using diesel as the pilot fuel and gas fuel as the main fuel can be used in Flexible switching between the two fuels, high fuel substitution rate, good power, economy and emissions. [0003] The existing in-cylinder direct-injection dual-fuel engines mostly use electromagnetically controlled gas nozzles and fu...

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Problems solved by technology

[0003] The existing in-cylinder direct-injection dual-fuel engines mostly use electromagnetically controlled gas nozzles and fuel nozzles, and gas boosters mostly use high-pressure pumps to compress the gas to a specified pressure. Although the timing of the needle valve movement controlled by the solenoid valve is controllable, the solenoid valve control device is affected by the hysteresis loop and the inductance of the electromagnetic coil, and the needle valve response is delayed relative to the control signal, which affects the control accuracy; the high-pressure pump has a complex structure, from the pump end to the The transmission pipeline of the gas nozzle is long, and there is a certain leakage of the pressurized gas; the gas nozzle and the fuel nozzle are independently installed on the cylinder head, and the size and installation position are limited by the cylinder head; the gas nozzle uses the pressure gas to lift the needle valve, but due to the gas Strong compressibility is not conducive to the precise control of needle valve movement, and the gas injection is unstable; in addition, during the gas injection process, with the movement of the needle valve, the leakage of gas to the solenoid valve end through the gap between the needle valve and the valve body intensifies, It leads to the reduction of gas injection pressure and injection rate, which has a negative impact on the stability of gas injection and affects engine power and fuel economy.

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