The working principle of the diesel generator set is explained in this way the working process of the diesel generator set: in the diesel engine cylinder, the clean air filtered by the air filter is fully mixed with the high-pressure atomized diesel injected by the fuel nozzle, and the volume is reduced under the upward extrusion of the piston, the temperature is increased, and the burning point of the diesel is reached. Diesel is ignited, the mixed gas burns violently, the volume expands rapidly, and the piston is pushed down, which is called work. Each cylinder does work in a certain order, and the thrust acting on the piston becomes the force driving the crankshaft through the connecting rod, thus driving the crankshaft to rotate. Then the diesel generator injector must have a good atomization function when working, so as to ensure that the diesel generator fuel is completely burned, ensure that the color of the diesel generator is normal, and ensure that the diesel generator power is normal. What are the causes of poor fuel atomization? In use, try to avoid the occurrence of poor fuel spray atomization failure.
The process of dispersing fuel into fine particles is called fuel spraying (or atomization). The spray atomization of fuel can greatly increase the surface area of fuel evaporation and increase the chance of fuel contact with oxygen to achieve the purpose of rapid mixing. There are many factors that affect the characteristics of the oil beam, such as the structure and size of the injector, the injection pressure, the back pressure of the compressed air in the cylinder, the shape and speed of the injection pump CAM and the viscosity of the fuel.
(1) Fuel injector structure and size.
The internal disturbance caused by the different structure of the injector is also different, thus producing different forms of oil bundle. The oil bundle should be closely coordinated with the combustion system, and different combustion modes require different forms of the oil bundle, so different fuel injectors are used.
When the fuel injection pressure and the compressed air pressure of the cylinder are unchanged and the total cross-sectional area of the jet hole is unchanged, the diameter of each jet hole will be reduced by increasing the number of jet holes, and the fuel will be more restricted when flowing out of the jet hole, and the disturbance in the jet hole will increase, so the atomization quality will be improved. If the diameter of the nozzle is increased, the core of the oil bundle is dense and the range is increased.
(2) injection pressure.
The greater the injection pressure of the fuel, the greater the initial velocity of the fuel outflow, the greater the degree of fuel disturbance in the jet hole and the compressed air resistance after the outflow of the jet hole, so that the fineness and uniformity of the atomization are improved, that is, the atomization quality is good. When the injection pressure is increased, the oil beam range is also increased.
(3) Back pressure of compressed air in the cylinder.
When the back pressure of the compressed air in the cylinder increases, the density of the compressed air increases, causing the air resistance acting on the oil bundle to increase, so the fuel atomization is improved, the spray cone Angle is increased, and the range is reduced. In a non-pressurized diesel generator, the reverse pressure of the compressed air in the cylinder does not change much, so the effect on the oil beam characteristics is not significant.
(4) Shape and speed of the injection pump CAM.
When the CAM shape is steeper or the camshaft speed is higher, the fuel supply speed of the injection pump plunger is accelerated. Due to the throttle of the injector hole, the fuel can not flow out quickly, resulting in an increase in the fuel pressure in the tubing, and the speed of the fuel flowing out of the jet hole is also increased, so the atomization is better, the oil beam range and the spray cone Angle are increased.
If the combustion of diesel generator set is not sufficient, it is easy to cause air pollution, and it will endanger the personal safety of the operator when serious, and some methods can be used to improve fuel to reduce pollution.
(1) Water intake pipe
The main function of water intake pipe is to absorb heat and dilute fuel density. When a small amount of water enters the combustion chamber and atomizes well, due to the “micro-explosion” effect of water vapor, the oil droplets are broken into smaller oil droplets, thus promoting the formation and combustion of the mixture, in the combustion process due to the endothermal effect of water can reduce the maximum combustion temperature, such as water and oil mixed into the fuel density can be reduced, the maximum combustion temperature can be further reduced, so NOx emissions are reduced. It should be noted that the diesel generator set winter water storage tank should be antifreeze, and it is required to automatically adjust the water spraying amount with the load size.
(2) Emulsified diesel oil
The addition of water to diesel oil, that is, emulsified diesel oil, because of its “explosion” effect, so that the fuel atomization is good, and promote the air in the combustion chamber to form strong turbulence, the distribution of fuel and air is more uniform, the generated carbon smoke is reduced, and the water-gas reaction of water vapor also reduces the carbon smoke emission. In addition, emulsified diesel can reduce the maximum combustion temperature, so the nox generation is reduced.
Post time: Jul-06-2023