With the rising fuel price, users pay more and more attention to the fuel consumption of construction machinery. In the daily use of construction machinery, the operator should not only master the appropriate operation methods, but also regularly maintain the electronic control system, hydraulic system, diesel engine fuel system and air intake system, so as to ensure that the diesel engine works in the best state.
Although the maintenance of the machine is important, before the above maintenance, we must also understand the correct management and use of fuel, otherwise the maintenance of diesel engine fuel system will not play a great role.
Due to the heavy workload and environmental problems, most of China's construction machinery will be used under severe working conditions. Most of the engine failures of construction machinery products are due to poor management of oil, water and gas.
Generally, fuel pollution refers to the following situations:
(1) High moisture content.
(2) It contains much sand and dust.
(3) The content of heavy oil is high.
(4) The content of paraffin is high.
(5) High sulfur content.
This article will briefly introduce the impact of high water content of diesel oil.
Take common rail diesel engine as an example. In short, the high water content in the fuel will accelerate the wear of the plunger, plunger sleeve and injector needle valve of the fuel injection pump, resulting in the failure of injection pressure drop, poor atomization, black smoke and engine power drop. The conical surface of the injector needle valve assembly and the intermediate needle valve is easy to wear, which affects the injection quantity of the injector.
The water content of normal high-quality diesel oil shall be lower than 0.03%. Too high water content will have a great impact on the quality of fuel oil, including:
(1) After the water content of the fuel increases, the viscosity decreases, which reduces the lubrication performance of the mating parts of the fuel injector and oil pump, reduces the lubrication protection of the sealing surface of the needle valve and accelerates the wear of the parts.
(2) The water entering the diesel from the outside is not clean enough and may contain a lot of impurities and various inorganic salts, which will aggravate the wear and corrosion of the matching surface and sealing surface of the fuel injector.
(3) The increase of water content will lead to the proliferation of bacteria in the mailbox. At present, the sulfur content of diesel oil in China's market is high, so it will produce more acidic substances, destroy the acid-base balance of fuel and increase the corrosion degree of parts.
(4) The fuel with high water content has low viscosity. The filter element surface of the secondary filter cannot form a good oil film to assist the filter in filtering impurities, which will allow more large particle impurities to pass through the filter element, and the filter element will be greatly damaged under the influence of moisture and impurities, resulting in poor filtering capacity.
In short, the high water content of fuel has a very serious impact on the fuel injector, and also damages other components of the fuel supply system such as the oil pump, but the fuel injector fault is more likely to occur and has a more direct impact on the engine performance.
