Abstract
Research and/or engineering question/objective
Environmental issues make energy more valuable and it is common knowledge that roughly two thirds of the energy released by the combustion of gasoline is wasted through the coolant fluid and the exhaust gases. So, it is necessary to use it with a high efficiency. Different solutions can be studied.
For example thermoelectric generators, heat engines based on different thermodynamic cycles and the turbo compound are among the most promising solutions. The research presented here focuses on the valorization of the energy in the exhaust gas with a Rankine cycle.
Methodology
A test bench has been built in order to measure the energy performance of a prototype of Rankine cycle system. The test bench includes a gasoline engine and an open Rankine cycle (the inlet of the pump is not connected to the outlet of the heat exchanger). This Rankine cycle works with water as the working fluid and uses a volumetric expander.
Some tests have been conducted to evaluate the performance of the whole system as well as those of the different components. Different evaporators have been tested in order to compare their performance and evaluate their ability to recover a given amount of heat. The evaporator also introduces a back pressure at the exhaust of the engine. This pressure drop should be kept as limited as possible in order not to decrease the engine efficiency. This key parameter will also be presented.
Some models have also been developed and are used to analyze the results. Those models have been calibrated and are used to conduct the analysis of the experimental data.
Results
Measurements presented in this paper constitute the first set of measurements collected on this test bench. The performances of the evaporators are introduced and some models are calibrated based on those measurements.
What does the paper offer that is new in the field in comparison to other works of the author?
The paper will present some experimental results and some calibrated models based on those results. A strong analysis of the results will also be conducted.
Conclusion
Based on the calibration of the model of each component, a model of the global Rankine cycle system can be built. This model allows the prediction of the performance of such a system introduced on a gasoline engine in real conditions.
KEYWORDS – Rankine cycle, waste heat recovery, gasoline engine, evaporator, expander