Talking about the characteristics of closed-cycle and open-cycle cooling systems for diesel generator sets

The water cooling system of diesel generator are forced circulation water cooling device, that is, the use of water pump to increase the pressure of coolant, forced coolant circulation flow in the diesel generator. The forced circulation water cooling system of diesel generator sets is to use the water pump to pressurize the coolant of the system and make it flow in the water jacket. The cooling water absorbs heat from the cylinder wall, the temperature rises and the hot water flows upward into the cylinder head, and then flows out from the cylinder head and into the radiator.

Diesel generator

 

The water cooling system of diesel generators are all forced circulation water cooling devices, that is, the use of water pumps to increase the pressure of coolant, forcing the coolant to circulate in the diesel generator. Diesel generator forced circulation water cooling system is to use the pump to pressurize the coolant of the system, so that it flows in the water jacket, the cooling water absorbs heat from the cylinder wall, the temperature rises, the hot water flows upward into the cylinder head, and then out of the cylinder head and into the radiator. According to the different sources of cooling water, and divided into closed cycle and open cycle.

 

The closed cycle water cooling system consists of water pump, cooling water tank, thermostat, fan, etc.

 

Closed circulation water cooling system in the water cycle is forced under the pump, the water jacket inlet and outlet temperature difference is small (can not exceed 10 ° C), its work process is shown in the figure below. The water pump draws in low temperature water from the cooling water tank, raises the pressure and sends it to the oil cooler, then flows through the cylinder block and the cooling water jacket of the cylinder, takes away the heat and flows back to the cooling water tank through the return pipe for cooling. Cooling water continuously circulates to keep the working temperature of the internal combustion engine within a certain range. Usually the cooling water outlet temperature is 343~363K (70°C~90°C). Closed loop water cooling system is characterized by less water consumption, can keep the cooling water clean, easy to control the inlet water temperature, make the internal combustion engine work stable, and get a better economy. However, the structure is more complex, but also need to consume part of the power to drive the fan. The other is open cycle, cooling water is introduced from external water sources (such as pools, rivers, etc.) into the cooling part of the internal combustion engine, cooling the heated parts, and then discharged into the surrounding environment, using no cooling water tank, fan and other components, but the cooling intensity is not easy to adjust.

 

Internal combustion engine cooling system is generally designed for rated power operating conditions under high temperature climatic conditions, while in other operating conditions, the cooling system should be adjusted for cooling intensity, there are usually two ways to adjust the cooling water flow and air volume.

 

(1) cooling water flow rate adjustment. This adjustment is mostly controlled automatically with a thermostat. Thermostat according to the working water temperature so that the cooling water for large or small cycle, so as to change the cooling intensity.

 

(2) air volume adjustment. This adjustment method is mainly to adjust the amount of air flowing through the cooling water tank. There are two methods: one is to open or close the louvers in front of the cooling water tank according to different working conditions; the other is to change the fan speed according to different working conditions.