EFI diesel generator set and its technology

1 Introduction

Electronic injection technology supply EFI technology is the internal combustion engine fuel system, strict control of vehicle exhaust gas to the serious pollution of the environment, requirements of automotive gasoline engine must implement EFI technology, non access measures for non EFI car.

Due to the particularity of the fuel supply system, the diesel fuel is injected with high pressure (10 ~ 120MPa) when supplying the cylinder, and it is difficult to change the original oil supply mode technically compared with the gasoline engine. In fact, the pollution of diesel engines is sometimes more serious than gasoline engines, especially smoke exhaust and carbon oxygen compounds.

Diesel generator diesel engine only has stable operation speed, good dynamic performance, can output high quality electric power automation with speed adjustment, in order to truly realize the preparation (main) power automation and intelligence. Therefore, the diesel engine set of diesel generator sets has realized the electronic speed regulation in recent years, but the control measures of environmental pollution have done nothing.

EFI technology of 2 EFI diesel engine

Power generation diesel engines are variant products of diesel engines for vehicles, ships and construction machinery. Therefore, the development of electronic control technology is bound to be affected by the main products. In late twentieth Century, due to diesel exhaust emission regulations and gasoline cars is becoming more and more strict, while improving the fuel economy requirements is further improved, based on the rapid development of gasoline electric control technology, some developed countries started to control the electronic injection technology -- the development and research of diesel engine, and initially put into use. Electronic injection technology and electronic control technology not only has the same point (i.e. the control of diesel engine fuel injection quantity), and has a fundamental difference, namely electronic injection also has the signal control injection time and injection pressure, completely abolished the mechanical structure in the fuel system.

The electronically controlled diesel injection system developed in 1990s mainly has the following two forms:

One is Bosch common rail type electronically controlled diesel injection system. The utility model is characterized in that a high-pressure high-pressure oil rail is arranged in the system, and a high-pressure (or medium pressure) oil pump is used to pump oil in the public oil rail, and the pressure in the oil rail is regulated by an electromagnetic valve. High pressure (or pressure) of diesel oil by public rail to each cylinder injector, a solenoid valve in the fuel injector to control the fuel injection quantity and injection timing, injection pressure or direct decision; in the common rail pressure in or by the booster piston in the injector on the fuel rail from the public fuel pressure. The common rail type electronically controlled injection system can control the injection volume, injection timing, injection pressure, injection rate and oil rate at the same time, and achieve high pressure jet to meet the emission requirements. At the same time, when the traditional high-pressure oil pump, a high-pressure oil pipe, an injector, an injection system, a diesel engine are used, the structural change is very small.

Two is the Perkins company common rail type electronically controlled diesel injection system, which is based on the Bosch company EFI system improvement. The system has no high-pressure oil pump, and the EFI system is mainly composed of electronic control module (ECM), high pressure lubricating oil supply pump, injection pressure control valve, injector and so on. The sensors include crankshaft position sensors (CMP), boost pressure sensors (MAP), fuel injection pressure control sensors (1CP), lubricating oil moisture sensors (EOT), water temperature sensors (CET), and oil pressure sensors (EOP). The fuel flow in the system is shown in Figure 1. The fuel passes through the filter, the oil pump (low pressure) and the fuel collection pipe to the injector. The fuel system pressure, fuel flow, cancel the high-pressure tubing, this prevents the diesel elastic compressibility and tube formation pressure fluctuations in the oil pipe may cause the needle valve closed to open, have two times of injection of abnormal combustion, the incomplete combustion.

The fuel injection pressure control system is shown in Figure 2. The system consists of a high pressure oil pump, a pressure stabilizing valve, an injection pressure control inductor, a regulating valve, etc.. The system flows for high pressure engine oil. High pressure oil supply pump is a pump driven by the crankshaft seven pistons, under normal operating conditions, pump output pressure of a rail pressure control valve (RPCV) control, after too much oil through a bypass flow back to the oil return system, diesel engine operation depends on the fluid pressure, and pressure control depending on ECM, good hydraulic control of the diesel engine has good operating conditions.

The injector is shown in Figure 3: it consists of an electromagnetic valve, a poppet valve, an acidified piston, and a nozzle assembly. The injection power of the injector comes from hydraulic energy, and the piston and plunger in the injector are controlled by hydraulic pressure and speed. At the same time, the fuel injection quantity is ECM sends pulse time to control the switching time of solenoid valve injector in length, when the solenoid valve is energized, the valve poppet valve open, high pressure oil will push the piston and the piston downward until the minimum. When the ECM output signal disconnects the injector solenoid valve, the fuel injection procedure stops and the lift valve closes. As the lift valve closes, the high pressure oil delivery pipe closes and stops supplying oil to the acidified piston to increase the pressure of the high-pressure oil in the piston to rotate the empty slot. The plunger spring pushes the acidified piston and plunger back in place. When the plunger moves up, the fuel valve is opened, and the low-pressure fuel is injected into the plunger valve. ECM through its injector, the injection speed, injection time and high-pressure injection pressure are effectively controlled. Injection speed control: the injector is executed by the hydraulic system, which is faster than the conventional one. The injection speed and injection pressure are independent of the speed of the diesel engine.

Injection time control: from the beginning to the end of the injection time, fully electronic control