Kengo Tanaka, Yuki Iwano, Yasushi Kihara, Masato Sorimachi, Hisashi Ayuzawa
We have been developing a system in which waste heat from an automotive engine is stored during driving to warm up the engine oil, the transmission oil and others with the stored heat at a cold start. With the early warming up, the fuel efficiency can be improved because not only the combustion efficiency at a starting-up is improved but also because the friction loss of oil is reduced. Calcium oxide is typical as a heat storage material to make use of the heat in the temperature range of the exhaust heat. But, there is a problem that the device becomes large in size, because it is necessary to widen the surface area of the material to accelerate its reaction with the water vapor to gain a larger output. This is a barrier detrimental to the automotive use. We have been examining a compact heat storage system but with a high output and a high density which are realized with a combination of the heat-pipe technology and the heat storage material to make the material react directly with water (liquid) not with water vapor (gas). In our preliminary evaluation with a theoretical mock-up model, we have already got the data that shows that the heat output density was as high as double or more than that of the present heat storages.
Contact for inquiries about Furukawa Electric Review