Insulated Exhaust

The thermal load of the air-cooled diesel抯 cylinder head is higher than the water-cooled diesel. The heat insulating technique can effectively reduce it. This dissertation studies the engineering application of this technique. The main contents are as fellows: Design A thin wall steel shell of the exhaust port which can reach the requirements of mass production was designed. In the mean while, the existing cylinder head was redesigned too. M~nuf~ctu~ The mould design and the steel shell cast are the primary steps in the manufacture. The shape of the steel shell with the thickness of 2 mm and the length of over 100 mm is complex. In order to get right shape and uniform wall thickness, CAD/CAM method was used in the manufacture of the moulds and steel shell was made by the precision molten-wax casting method. Exp~ni~n~ The performance and reliability experiments were took to verif~,?the effects of heat insulating and the reliability of the cylinder head. The results show that the heat insulated exhaust port not only can decrease the cylinder head抯 thermal load, but also increase the diesel抯 power density. The reliability has passed the bench test. Siniu1~n The diesel performance before using the heat insulating technique and after was compared by numerical simulation.