Electric injection diesel generator set and its technology

1 the introduction

Ems or internal combustion engine fuel supply system of the electronic injection technology, in order to strictly control the vehicle exhaust serious pollution to the environment, for automotive gasoline engine must implement efi technology, for the efi car took the measures of access.

Due to the particularity of fuel supply system of diesel engine, the fuel on the supply when the cylinder is to adopt high-pressure (10 ~ 120 mpa) injection way, the technology change the way of fuel supply compared with gasoline engine has great difficulty. In fact, diesel engines are sometimes more polluted than gasoline engines, especially when it comes to smoking, carbohydrates, etc.

Diesel generator set for diesel engine only has run speed stability, good dynamic performance, can output high quality power, have the automation of speed adjustment at the same time, can we truly achieve (main) prepared with the power of the automatic and intelligent. Therefore, in recent years, some diesel engines with diesel generators have realized electronic speed regulation, but there is nothing to control environmental pollution.

2. Electric injection technology of electric injection diesel engine

The diesel engine for power generation is a kind of diesel engine for vehicle, ship and engineering machinery. Late in the 20th century, because of the diesel exhaust pollutants increasingly strict emission regulations and gasoline car, at the same time can also further improve, improve the efficiency in gasoline engine electronic control technology rapid development, on the basis of some developed countries started to diesel engine electronic control technology, electron injection has carried on the research and development, and put into use. Electronic injection technology and electronic speed technology has both similarities (i.e., control of diesel engine fuel injection quantity), but also has fundamental difference, namely the electronic injection also has a power signal control injection time, injection pressure, completely cancel the mechanical structure of the fuel system.

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

Bosch co. 's common rail electric diesel injection system. It is characterized by a common high pressure oil rail in the system, using high pressure (or medium pressure) oil pump to pump oil into the common oil rail, using electromagnetic valve to adjust the pressure in the oil rail. High pressure (or intermediate) separately to each cylinder diesel oil by public rail injector, installed in the fuel injector solenoid valve control the fuel injection quantity and injection timing, injection pressure or directly depends on the common rail pressure, or by the injector in the pressurization piston for pressurized fuel from public fuel rail. The common rail electric control oil injection system can control the amount of oil injection, the timing of oil injection, the pressure of oil injection, the rate of oil injection, and the high pressure injection can meet the discharge requirements. At the same time, the structure change is very small when it is used in the injection system diesel engine of traditional high pressure oil pump, high pressure oil pipe and injector.

Perkins's common rail electric diesel injection system is an improvement on Bosch's electric injection system. There is no high pressure oil pump in this system, and the electric injection system is mainly composed of electronic control module (ECM), high pressure lubricating oil supply pump, injection pressure regulating valve and injector. The sensors include: crankshaft position sensor (CMP), pressurized pressure sensor (MAP), injection pressure control sensor (1CP), lubricating oil humidity sensor (EOT), water temperature sensor (CET), oil pressure sensor (EOP). The fuel flow in the system is shown in figure 1. The fuel is transferred from the filter, oil pump (low pressure), fuel collecting pipe to the fuel injector. Fuel system, the high pressure fuel flow, cancelled the high pressure oil pipe, which can prevent the compressibility of diesel and the flexibility of tubing within the tubing pressure fluctuations, may cause the closed needle valve to open, produce abnormal combustion of secondary injection, the incomplete combustion.


Figure 1 fuel flow
The fuel injection pressure control system is shown in FIG. 2. The system consists of high pressure oil pump, stabilizing valve, fuel injection pressure control sensor, regulating valve, etc. The flow in the system is high pressure oil. High pressure oil supply pump is driven by the crankshaft seven piston pump, under the condition of normal operation, the pump output pressure through a rail pressure control valve (RPCV) control, excessive oil through the bypass back into the oil return system, the operation condition of diesel engine depends on the hydraulic pressure, and the control pressure is depends on the ECM, make good hydraulic control diesel engine has a good running condition.


FIG. 2 oil injection pressure control system
As shown in FIG. 3, the injector consists of electromagnetic valve, lifting valve, acidizing strengthening piston, nozzle assembly, etc. The jet power of the injector comes from hydraulic energy. The piston and plunger in the injector are controlled by hydraulic pressure and speed. At the same time, the fuel injection quantity is the ECM pulse of time to control the length of the fuel injector solenoid valve switch time, when the solenoid valve electricity, poppet valve open its seat, high pressure oil will push the piston and the plunger downward until the lowest. When the ECM output signal disconnects the solenoid valve power of the injector, the fuel injection program stops and the lifting valve closes. Due to the closing of the lifting valve, the high-pressure oil pipeline is closed, and the oil supply is stopped until the acidification strengthens the piston. In the acidification strengthens the piston, the high pressure oil drain is rotated into the empty slot. The plunger spring pushes the acidified strengthened piston and plunger back into position. When the plunger moves upward, open the fuel valve, and the low pressure fuel begins to fill the plunger disc. ECM can control the injection speed, injection time and high pressure through its injector. Control of injection speed: the fuel injector is operated by the hydraulic system. Its speed is faster than the traditional mechanical type, and its injection speed and pressure are independent of the diesel engine speed.


FIG. 3 fuel injector
Control the fuel injection time: from the beginning to the end of the full electronic control fuel injection time, different from general electronic governor, general electronic governor of its actuators are unified pull the plunger (rotation), and could not have independent control of each cylinder, and the system of fuel injector plunger is to use electromagnetic valve control respectively, and the movement of the plunger and the running speed of diesel engine or the duration of the crankshaft position sensor signal.

Injection pressure control, fuel injector acidizing increased hydraulic power drive plunger piston can produce multiplier, even if the input of high pressure oil pressure is not stable, but you still can maintain your injection pressure from 3000 to 21000 psi, the hydraulic pressure is also suitable for high speed diesel engine.

Electric injection diesel generator set

Perkins company electronically controlled common rail type diesel fuel injection system has been applied in will letter of 1300 series diesel generator, basic parameters of series 1300 diesel engines, cylinder diameter/schedule 116.6 mm / 135.5 mm, the compression ratio of 15.9:1, the number of cylinders for 6, power range from 145 kw to 145 kw of five levels.

Due to the series diesel generating sets of ECM system of mechanical or electronic governor more than signal input, therefore, can operate the best oil and fuel injection time, especially embodied in unit emissions and noise strictly comply with the latest international standards; At the same time, when the unit is started, the degree of black smoke emission is significantly reduced, and the explosion noise is significantly decreased when the unit is suddenly loaded. Meanwhile, compared with the same period last year, the power was increased by 3%, and the fuel consumption rate was reduced by 8%. Simple structure and simple operation. On the other hand, the ECM control system of electric injection diesel generator sets realizes the intelligence of diesel fuel supply system. Equipped with self-inspection function buttons and indicator lights as well as operation status flashing code display system, the electric spraying system has 145 fault display contents. Moreover, it has a speed monitoring interface, and the speed can be set and adjusted arbitrarily within a certain range, which has a strong applicability.

4 conclusion

Efi diesel generating sets, changed the original generator set control category, is the beginning of diesel generators to green units, because today, in the development of modern society, people have pay attention to the environment influence on social and economic sustainable development, has placed great emphasis on transportation, especially the pollution control of gasoline engine car, emphasizes the necessity of electronic injection control engine, and thus take the compulsory popularity. It is believed that in the near future, the popularization of electric injection technology of diesel engine is not far away.