A Test Bench for the Turbocharger Fatigue Life Based on the Self-Circulation

The low cycle fatigue experiment is extensively used to test the reliability and durability of turbocharger. Low cycle fatigue test is mainly the switching between high and low speed. As the result of the experiment, the fatigue life is shorter as the difference between high and low speed becomes greater. In the traditional low cycle fatigue test, a large air compressor is needed to drive the turbocharger under different operating conditions, which consume large amounts of electric power. This paper presents a new experiment device which has double chambers and double turbochargers. This device can be self-circulating, without the large air compressor, to realize high and low speed switching on the premise of not exceeding the limitation of turbine entry temperature. First, a detailed model is established in GT-Power and self-circulation test data has been used to validate the model. Then the relation between the valve opening and the flow distribution has been obtained depending on this model. Therefore a dynamic model has been built in MATLAB/Simulink, with which the dynamic relationship between fuel mass and turbocharger speed is obtained. At last, a fundamental control strategy for the switch of high and low speed of the turbocharger has been proposed and validated on the test bench.