| To meet the requirement of energy crisis and stringent exhaust emission legislations, more emphasis are laid on how to reduce both fuel consumption and emissions. There is a number of ways to achieve this objective. Out of these methods, emulsifying combustion is an effective one. Most of traditional diesel emulsifying combustion installations adopt emulsified fuels or use mechanical devices to control the water-fuel proportion, which have some disadvantages, such as unalterable water-fuel proportion, low accuracy of control, etc. Therefore, there is a need to develop a novel system of diesel online emulsifying combustion that is characterized as simple construction, accurate control, and variable water-fuel proportion.This system adopts AVR single-chip microcomputer as Micro Control Unit (MCU). According to the signals, including speed, exhaust temperature, etc, MCU differentiates working conditions of diesel, and then analyze, calculate, and check the data table to get the optimal water-fuel proportion that is sent to PWM to adjust the frequency of water-injection electromagnetic valve to get the water-fuel mixture with accurate proportion. The optimal proportions under different working conditions are acquired by engine bench tests. In addition, start and stop of emulsifying combustion can be controlled by a manual button, and the working condition signal and PWM duty ratio can be displayed by digital LED.Diesel bench test results show that fuel consumption and emissions are reduced obviously. Average reduction of fuel consumption, PM, and NOx emissions are 6%, 30%, and 25%, respectively. In addition, based on carefully examinations, this system, characterized as accurate water-fuel proportion, fast control response, and accurate data display, can be widely used in marine diesels, oil boilers, and oil electrical machines.
|
PDF Full Text Request