Key points for Starting Internal combustion engines in winter

The correct way to start in winter

(1) Pre-startup inspection. The quantity and quality of the lubricating oil in the oil pan as well as the tightness of all connections should be carefully inspected.

(2) Preheat first before starting. Practical experience has found that when the temperature is below -10℃, using the cold climate start-up auxiliary preheating device for internal combustion engines alone can only quickly start the internal combustion engine and cannot solve the problem of wear and brush acceleration of the internal combustion engine during cold conditions. Therefore, it is recommended that when starting an internal combustion engine at a temperature below -3℃, it is best to combine the cold climate start assist device with preheating under external conditions. For instance, hot water above 50℃ can be directly added to the cooling system, or hot air or steam can be used to heat the oil pan, cylinder block, fuel injection pump, etc. For instance, our department has specially developed a preheating machine for starting under extremely cold conditions. By using the hot air above 300℃ sprayed out after diesel combustion, the body temperature can be rapidly raised, the viscosity of the lubricating oil can be reduced, and the starting resistance can be decreased. This method is simple and convenient, and the effect is obvious.

(3) It is recommended to add backup batteries for pre-operation. Before the ignition starts, the starter drives the internal combustion engine to rotate in advance at a speed of 150 to 200r/min (without supplying power to the fuel system), delivering and splashing a certain amount of lubricating oil onto each lubricated surface to meet the most basic lubricating oil requirements between each moving pair, thereby reducing the wear between each component during startup. However, this method consumes a relatively large amount of capacity from the battery. Take the Cummins C series internal combustion engine as an example. When started with a 24V battery, the cold start current is 900A when the temperature is -18℃. When the temperature is 0℃, the cold start current is 640A, so a spare battery needs to be added. When using this method, it is also necessary to strictly follow the start-up precautions. Each rotation should not exceed 15 seconds, the interval between each rotation should be no less than 2 minutes, and the total number of rotations should not exceed 3.

(4) After starting, it should idle for 3 to 5 minutes. After the internal combustion engine is started, it cannot run at high speed immediately. It can only be put into operation after the lubricating oil reaches the standard pressure and the body temperature rises to 50 to 60 degrees Celsius. When the temperatures of both the internal combustion engine and the lubricating oil are relatively low, the resistance between the moving pairs increases, making it difficult for the lubricating oil to flow and form an oil film. For the same grade of lubricating oil, when its temperature drops from 50℃ to 0℃, its kinematic viscosity will decrease to a few tens of its original. However, do not idle for a long time either, as this will cause the combustion chamber temperature to be too low, resulting in incomplete combustion of the fuel and the formation of carbon deposits, which will also increase the wear of the components.