In a modern passenger vehicle, more than 70% of the fuel energy is lost to the environment as waste heat. In contrast, a lack of heat during the cold start results in an increase of fuel consumption of e.g. up to 15% in a NEDC started at 20 °C. This apparent conflict can be solved by storing the otherwise lost waste heat and return and use it during the next cold start for a more rapid engine and cabin warm up. An exhaust heat exchanger transfers part for the exhaust waste heat into a heat storage device which uses a phase change material on salt basis. A high-vacuum isolation provides low-loss storing overnight. During the cold start, e.g. at the next morning, the stored heat is used for heating the engine coolant, engine oil, gear oil and the passenger cabin. The fuel reduction benefit of a different heat split-up into these competing heat sinks was analysed and evaluated by a large scale of test series. An experimental research car including a 1,4 liter 90 kW TSI gasoline engine was equipped and tested on roller test bench and on the road. A significant fuel/CO2 reduction could be verified for the NEDC and for typical customer cycles. Additionally, the comfort level was improved considerably by supplying increased cabin heating power during the cold start.
Exhaust energy recovery by PCM heat storage
2012
13 Seiten, 15 Bilder, 3 Quellen
Aufsatz (Konferenz)
Englisch
Exhaust energy recovery by PCM heat storage
Kraftfahrwesen | 2012
|Europäisches Patentamt | 2021
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