Design Of Exhaust Waste Heat Generator On WD615 Engine

Issues about energy and environment have been paid unprecedented attention to all over the world, "United Nations Framework Convention on Climate Change" was discussed at the Copenhagen World Conference on environment by representatives coming from 192 countries in December 2009. Premier Wen Jiabao has attended to the work of energy saving as the leader of the leading group for energy saving which was established by State Council in China in 2007.Internal combustion engine is currently most widely used dynamic mechanic, but thermal efficiency of existing internal combustion engine is only about 40%, about 60% energy has been not utilized effectively and released into the atmosphere in the form of exhaust gas causing huge economic losses and serious environmental pollution.The research purpose of this subject is to recover and utilize exhaust waste heat on WD615 engine to save energy and reduce exhaust.Thermoelectric generator based on direct thermoelectric conversion principle (thermoelectric effect) has so many advantages such as simple structure, no moving parts, no noise, etc,and it has an unique function in the use of low-grade heat. Thermoelectric generator can convert exhaust waste heat from running internal combustion engines to electric energy directly due to installing in the exhaust pipe of the engine.Affected by the internal combustion engine working process and power variation etc, the exhaust pipe has a pulse of gas, exhaust temperature,pressure and flow rate and other parameters change at random, so the exhaust can not provide a stable heat source,it will have a great influence on the generator performanceBased on heat transfer theory and storage technology of phase change energy, convection heat transfering takes place between fin-tube heat exchanger and the hot exhaust in order to not only improve the exhaust heat recovery, but also reduce the size of the generator setting, and the rate of waste heat recovery reaches 59.6%. Phase-change materials has been used in endothermic or exothermic phase transition to store or release energy,the great advantage of energy storage of phase change over thermal energy storage of chemical reactions is high-density heat storage, heat is stored and released in almost the isothermal process. So it can provide stable heat source and optimize the performance for thermoelectric generator.The setting of exhaust waste heat on WD615 engine based on the above principle has been designed. Through calculation, the efficency of setting is 1.14%;Utilizing 43% of heat in designed heat source exchanger, thermoelectric generator can produce the biggest voltage 1831 V and the biggest output power 603.4 W.This research has provided a efficent way to utilize exhaust waste heat efficently on WD615 engine, and a guide to save energy and reduce exhaust. It will be of great impotance.