Correct maintenance and use of turbocharger for excavator
The turbocharger uses the exhaust gas from the engine to drive the turbine. How is it advanced or a set of mechanical devices, because its working environment is often working at high speed and high temperature, the temperature of the turbocharger exhaust gas turbine is above 600 degrees and the speed of the supercharger is very high, so in order to ensure the normal work of the supercharger. It is very important for the correct use and maintenance of it.
Under low temperature conditions, the fuel viscosity increases and is not conducive to the atomization and combustion of fuel. The flow variation of the lubricating oil increases the resistance of each component, and the decrease of the working capacity of the battery, which can easily lead to the difficulty of the engine start-up, the wear of the parts, the decrease of the power, the increase of fuel consumption and the decline of the power performance. . In order to ensure that all kinds of construction machinery can be safely put into operation under cold conditions, routine maintenance should be done well, and low temperature auxiliary starting system should be installed.
Four common low temperature starting methods
(1) the injection of cold starter
Cold starting fluid is a kind of auxiliary starting fuel (consisting of ether, low volatile hydrocarbon and low pour point oil with additive). The low condensation oil with additive can improve the lubrication condition of cylinder wall and achieve the purpose of starting. As the ether has good volatility, easy igniting and easy to press burning, the more the ether content, the lower the temperature of the diesel engine can start directly, but the higher the working degree of the diesel engine will be when starting. Therefore, when using cold starting fluid, it must be added according to the prescribed quantity, and must not be added too much. This starting method can start the engine in a moment, but because of the low temperature and viscosity of the engine oil at this time, there is not much oil in the cylinder wall in a certain period of time after starting, and the lubrication condition is bad. The dry friction between the engine working time and the rotary motion will cause the wear of the machine parts to aggravate; therefore, the wear of the machine parts is aggravated. When the cold starter is used to start the engine, we should not increase the operation of the throttle. When this starting mode is selected, the better atomizing starting fluid should be selected, and the injection time, the injection position and the injection amount are well controlled. In addition, it should not be sprayed directly into the starting fluid from the air inlet of the air filter, so as not to affect the quality of the filter core of the air filter and to increase the injection amount of the lifting liquid, thus causing the engine refrigerator to start running over speed. According to the above instructions, it is recommended to use cold water carefully.
(2) circulating water heating system (also known as fuel heater heating system)
This is a new type of low temperature auxiliary starting method used in recent years. This kind of low temperature starting mode is through the fuel heater. The auxiliary pump will pump out the coolant in the engine body, and heat the engine through the fuel heater and recycle it into the engine body, so that the engine can be heated to start the engine at low temperature. .
The whole heating process of this low temperature starting mode needs 30-40min, which can heat the engine body temperature to about 40-50 C, then the engine oil is also heated, the viscosity of the engine oil is reduced, the engine's lubrication condition is improved under the low temperature condition, so that the engine will start smoothly. This low temperature start-up method has obvious advantages, which greatly improves the startup performance of the engine under low temperature and cold conditions. This low temperature startup method is adopted on the ZLG50C highland loader and TLG210A high prototype bulldozer, and the starting effect is good.
(3) fire preheating start
The lowest working temperature of the flame preheating device is -40 C, and the working process is electronic automatic control. The flame preheating starting device is generally composed of an electronic controller, an electromagnetic valve, a temperature sensor, a flame preheating plug, a fuel pipe and a conducting wire. The working process of the device is that the electric heating plug is heated to the starting machine after 850-950 C, the solenoid valve opens the oil path automatically, supplies the oil through the fuel pipe to the electric heating plug, and starts the flame preheating. After using this device to start the engine, the engine oil has a low temperature and a larger viscosity at this time, and the cylinder wall is on the wall after starting for a period of time. There is not much oil and bad lubrication conditions. The dry friction between the reciprocating movement and the rotary motion in the engine working time is also formed, which will aggravate the wear of the machine parts. Because the high temperature produced in the friction can melt the metal of the friction surface, it is very easy to cause the die to die. Therefore, after using the flame preheating device to start the engine, it is also necessary to avoid increasing the throttle operation, otherwise it will easily cause cylinder failure.
(4) other preheating methods
In addition to the above preheating method, the hot water preheating method (hot water hot to boiling point is injected into the cooling system), the steam preheating method (the steam through the pipe from the pipe from the water tank to the cooling system, or directly into the engine cooling water jacket), the electric preheating method (the heater is inserted directly into the cooling system or the engine oil, the thermal efficiency of this method) High, easy to use) and other methods for low temperature start-up.
