Internal combustion engine cooling system with elevated coolant temperature research on the model test stand

In the paper a model test stand designed and built using original components of diesel engine 4CT90 is presented. The stand provides working conditions as close as possible to the exploitation conditions of the engine cooling system. This applies both to the intensity of heat inside the cylinders of the engine, the temperature uniformity along the cylinder axis, as well as variable-speed water pump. Research carried out on the model stand were aimed at checking the operation of the cooling intensity control with varying levels of filling of the cooling system and develop a control method of the cooling system before testing on the dynamometer stand. In addition, system operation at elevated cooling liquid pressure for the possibility of obtaining the elevated coolant temperature were checked. The influence of working conditions on the level of the temperature was also analysed. In this paper, the characteristics selected for two values of pressure, for 0.15 MPa and 0.2 MPa, and for two different values of the degree of filling of the cooling liquid were presented. During the warming-up and continuous heating of the cylinder and the cylinder head by electrical heaters, temperature and overpressure courses before and after the liquid radiator, temperature before the inlet and outlet of the liquid from the engine and the temperature at selected points inside the engine water jacket are designated. The results of measurements of the coolant pump flow at different speed water pump were also presented in this paper.