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What is the difference between the speed regulation mode of diesel generator EFI and ESC

April 20, 2022
Diesel generator speed regulation methods include: EFI and ESC. Relatively speaking, the speed regulation optimization of EFI is more obvious. Because the fuel supply system of the EFI engine does not depend on the injection pressure control of the rotational speed and load, the appropriate injection pressure can be selected for continuous injection, so that the diesel generator set can maintain good economic performance and low exhaust emission under various operating conditions.
The speed regulation methods of diesel generators are: EFI and ESC. Both belong to electronic speed regulation, the difference lies in the control method of mechanical speed regulation.
1. Execution method of speed regulation control: The ESC is a speed controller that feeds back the speed signal of the machine by a speed sensor. The speed controller compares the preset speed value and converts the difference into a speed regulation signal to drive the actuator to control The oil supply rack or sliding sleeve is used to realize speed regulation, the oil supply signal only depends on the speed signal, and the adjustment of the oil supply amount is realized by the mechanical action of the actuator.
The EFI uses sensors such as rotational speed, fuel injection time, intake air temperature, intake pressure, fuel temperature, and cooling water temperature to transmit signals, and input the real-time detected data into the computer (ECU) at the same time, and store the set parameter values. Or parameter map (MAP) for comparison, after processing and calculation, the instruction is sent to the executor according to the calculated target value.
2. Fuel injection pressure: The ESC injects diesel oil into the cylinder through a traditional high-pressure fuel pump, and its injection pressure is limited by the pressure valve on the injector. After the fuel pressure in the high-pressure fuel pipe reaches the set value of the pressure valve, the When the valve is opened and injected into the cylinder, the pressure of the pressure valve cannot be very large due to the influence of mechanical manufacturing.
The EFI is produced by the high-pressure oil pump in the high-pressure oil chamber of the injector, and the injector is controlled by the solenoid valve to inject fuel. The pressure of the oil is not affected by the pressure valve, so the pressure can be increased a lot, and the diesel injection pressure is increased from 100MPa to 180MPa. The injection pressure significantly improves the mixing quality of diesel and air, shortens the ignition delay time, and makes combustion more rapid and thorough, thereby reducing exhaust emissions.
3. Independent injection pressure control: The injection pressure of the oil supply system of the high-pressure oil pump of the ESC is related to the speed load of the diesel engine. This characteristic is detrimental to fuel economy and emissions at low rpm, part load conditions.
The fuel supply system of the EFI engine does not depend on the injection pressure control of the speed and load, and can select the appropriate injection pressure for continuous injection, so that the diesel generator set maintains good economic performance and low exhaust emissions under various operating conditions.
4. Independent fuel injection timing control: The high-pressure pump of the ESC is driven by the camshaft of the engine, and the injection timing depends on the camshaft to rotate the angle. Generally, its injection timing will be fixed after adjustment.
The injection timing of the EFI is adjusted by the electronic control system controlling the solenoid valve. The ability to control injection timing independent of machine rotation, a key measure of balance is achieved between fuel consumption and emissions.
5. Quick fuel cut-off capability: The fuel should be cut off quickly at the end of the injection. If the fuel cannot be cut off quickly, the diesel will be injected under low pressure, resulting in insufficient combustion and black smoke, increasing exhaust emissions. The high-speed electromagnetic switch valve used in the fuel injector of the EFI can quickly cut off the fuel. The high-pressure oil pump of the ESC cannot do this.
To sum up, the speed regulation method of diesel generator EFI is slightly better. JUNVOCH has always been committed to providing customers with comprehensive and considerate one-stop diesel generator set solutions. From product design, supply, commissioning and maintenance, we carefully consider everything for you, and provide you with all-round pure spare parts, technical consultation, installation guidance, free commissioning, free maintenance, unit transformation and personnel training. Five-star Worry-free after-sales service.