Analysis and Optimization of the cooling system in
an engine test bench
The cooling system of an engine test bench is designed to operate at standard conditions at 90° C as set point temperature for the coolant fluid. These operating conditions are generally obtained through the action of a thermostatic valve.
When the engine has to be tested out of design conditions, the behavior of the cooling system has to be examined and verified as well to check its ability to satisfy the cooling requirements at lower coolant fluid temperatures, even when the thermostatic valve is excluded.
A lot of work was done and several tests were carried out that immediately showed the inadequacy of the system to work efficiently at lower coolant fluid temperature levels. The reasons for limitations in the existing setup needed a well structured investigation plan and a detailed study of the heat transfer processes active in the whole system.
A model was built up to evaluate the heat power to be disposed off from the engine, as well as that dissipated by convection and conduction from the test bench to the environment and all the heat losses.
A Matlab model for the heat exchanger in the cooling test bench was also set up. This allowed to describe the heat exchanger performance when the engine demand changed, even with limited input information,. In addition, assessments about system dynamics and thermal capacity of the plant were performed. A clear understanding was so reached of the causes of failure and effective solutions were proposed and implemented to improve the test bench setup overcoming the proven limitations.