The heat dissipation efficiency of the cooling system of a small excavator directly affects its external dimensions and plays a very important role in the layout of the engine compartment. Using the heat transfer theory, by establishing a heat exchange model of the cooling system, the quantitative relationship between each structural parameter and the thermal equilibrium temperature is theoretically established, and the calculation method for measuring the heat dissipation efficiency is determined;
The thermal equilibrium theoretical results and test results of the series and parallel cooling systems are compared and analyzed. The results show that the maximum deviation between the two is 1.9℃, and compared with the series arrangement, the cooling efficiency of the coolant radiator and the hydraulic oil radiator of the parallel cooling system are increased by 7.9% and 6.0% respectively, further verifying the accuracy of the theoretical analysis and design methods.
The heat dissipation of the engine of the small excavator adopts suction air cooling, which can make the air passing through the radiator core obtain good distribution. To ensure the original heat dissipation effect of the engine of the small excavator in use, it is necessary to ensure the integrity of the heat dissipation-related parts.
The following aspects affect the heat dissipation effect: the filler around the radiator, commonly known as “sponge”. But it cannot be replaced by any “sponge”. The requirements for it on small excavators are that it must have good corrosion resistance and temperature resistance, and poor ventilation, because its main function is to prevent hot air from flowing back, that is, to prevent the cold air sucked from the front of the radiator from flowing back to the front of the radiator when the temperature rises and then enters the rear of the radiator (engine compartment). During the operation of the small excavator, the ventilation area of the radiator core is easily blocked by air movement and various reasons. If there is a protective net, the obstacles need to be handled on time. If there is no protective net, the external pollutants of the radiator need to be cleaned and cleaned according to environmental changes and construction conditions.
