Composition and Operating Process of the Diesel Generator Set Water Cooling System:

Due to water's high specific heat capacity and its excellent heat transfer properties between parts and cooling mediums, modern diesel generator sets predominantly use water cooling. Engines that use water as the cooling medium are known as water-cooled engines. The coolant is simply water. The internal combustion engine's water cooling system uses water as a medium to cool heated components and then transfers the heat to the air. The advantage of this cooling method is that it provides more uniform cooling and the cooling intensity is easily adjustable, allowing the internal combustion engine to operate within an optimal temperature range. Additionally, in winter, the engine can be preheated for easier starting by filling it with hot water or using auxiliary electric heating. Therefore, it is widely used.

The cooling system of diesel engines is typically forced liquid cooling, also known as pressure liquid cooling, meaning that all diesel engines are equipped with a dedicated cooling pump to circulate the cooling fluid. Depending on the operating conditions of the diesel engine, either an open-loop cooling or closed-loop cooling method can be adopted.

(1) Open Loop Cooling System. An open loop cooling system refers to the intake and exhaust water ports of the diesel engine being open, where the water source is connected by the user during operation. The configuration of the open loop cooling system varies slightly depending on the diesel engine model and the arrangement of the oil cooler. The flow of the coolant is as shown in the diagram.

During the operation of the diesel engine, the incoming water temperature must not be below 60°C. Therefore, appropriate measures should be taken for the water used in the open-loop cooling system to regulate the suitable incoming water temperature. Generally, a mixing tank (pond) can be installed between the water source and the diesel engine. Connect the engine's in and out water outlets to the mixing tank, and by controlling the amount of cold water entering the mixing tank, the incoming water temperature of the diesel engine can be controlled.

Closed-loop diesel engine coolant flow

(2) Closed-loop Cooling System. A closed-loop cooling system refers to the diesel engine cooling system, which forms a complete and sealed recirculating loop in itself. For land-based diesel engines, the closed-loop cooling system involves high-temperature coolant leaving the diesel engine, being cooled by a water radiator with the strong wind generated by a fan, and then the cooled water returning to cool the diesel engine. The closed-loop cooling system varies depending on the engine model and the use of an oil cooler.

12-cylinder V-type land-based diesel engine closed-loop coolant flow

Diesel engine closed-loop coolant flow (the oil cooler is air-cooled)