The Function and Cooling Method of The Engine's Cooling System

The working principle of the cooling system of a diesel generator set is heat transfer. Heat always moves from hot objects to cold objects. There are three ways of heat transfer: conduction, convection, and radiation. Conduction refers to the heat transfer between two solid objects. For example, heat is transferred from the valve stem to the valve guide. Due to both objects being solid, heat is transferred from the hot air rod to the cold valve guide through conduction. For example, heat is transferred from the air duct to the cylinder head through conduction. Heat can be transferred through convection. Convection is the heat transfer that occurs through the circulation of heat in a liquid or gas. Through convection, the heat from the hot cylinder body is transferred to the coolant, and when the hot radiator components transfer heat to the surrounding cold air, convection also occurs.

Radiation is a way of heat transfer. Radiation is the heat transfer that occurs by converting thermal energy into radiant energy. Any hot object emits radiation heat through conduction, and the hotter the object, the greater the radiation energy. When the diesel engine is hot, some of the heat is converted into radiation, approximately 8%. The cooling system removes excess heat from the engine based on these principles. For example, when a person approaches a running engine or other heat source object, although they have not approached it, they can already feel that the engine is hot, which is due to thermal radiation. In order to ensure the optimal operation of the unit engine, a cooling system is necessary. Engine manufacturers typically use two types of cooling systems: hot air (air) cooling systems and liquid (water) cooling systems, corresponding to air-cooled engines and liquid cooled engines.

Function and cooling method of cooling system

When an internal combustion engine is in operation, the combustion of fuel in the cylinder generates a large amount of heat, causing the gas temperature inside the cylinder to reach up to 2200~2800K (about 1900~2500C). About one tenth of the heat released by fuel combustion is absorbed by internal combustion engine components. In this way, if the components that come into direct contact with high-temperature gases (such as cylinder liners, cylinder heads, pistons, valves, etc.) are not cooled in a timely manner after being heated, the moving components may expand due to heat and damage the normal clearance, or get stuck due to the failure of lubricating oil. The mechanical strength of each component may also decrease or even be damaged due to high temperature, leading to a decrease in cylinder filling and abnormal combustion. Therefore, in order to ensure the normal operation of internal combustion engines, it is necessary to cool these components that work under high temperature conditions. Of course, the cooling of internal combustion engines must be moderate. If the cooling is excessive, on the one hand, due to excessive heat loss, the amount of heat converted into useful work decreases; On the other hand, the temperature is too low Not conducive to the formation and combustion of combustible mixtures.

The working temperature of an internal combustion engine, whether too high or too low, will reduce its power and economy. The function of the cooling system is to maintain the most suitable working temperature of the internal combustion engine, and to exert its good economy, power, reliability, and durability.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.