Experimental determination of turbocharger heat flows for validation of a power separation approach

Abstract

This work presents a new method to measure the heat flow from a turbocharger to the ambient air. The experimental setup, performed on a hot gas test bench, includes an insulated box with two openings, encapsulating the turbocharger. These openings enable a controlled air flow through the box, which is measured at the inlet duct of the box. With temperature measurements at the inlet and outlet of the box, the quantitative heat flow can be calculated. With this information, an approach to estimate those heat flows from standard turbocharger test bench measurements can be validated and refined. The performed measurements at different turbine inlet temperatures and turbine mass flows show a good conformity with expected heat flows. Due to convective and radiative effects, the heat flows increase with both turbine mass flow and turbine inlet temperature. However, the setup with the insulated box has an effect on the overall thermal conditions, since the convection around the turbocharger decreases if the specimen is not as exposed as in common test bench setups.