Plastic encapsulation of engine cuts fuel cost by 9%

Researchers are using simulation software to look at methods of thermally encapsulating vehicle engines with polyurethane in order to reduce emissions and cut fuel consumption

Plastics manufacturing giant BASF and researchers at Cologne University have successfully demonstrated that an engine that is thermally encapsulated with polyurethane (PU) will reduce fuel consumption in the Winter months of around 9% and 5% during the Summer. The polyurethane used for the trials was TEE, supplied by BASF. The PU enclosure for the engine, a 1.4 litre, four cylinder gasoline engine would typically consist of at least eight pieces to enable easy access to the engine during maintenance. Those areas subjected to extreme heat - from the exhaust manifold or catalytic converter for example - would be insulated by a refractory material and metal cladding. Speaking at a recent conference in Germany, Hermann Volker, head of technical market development automotive at BASF, explained further: "The idea behind using TEE is to reduce the number of cold starts by slowing the loss of heat from the engine after it has been switched off. This means less engine wear, faster de-icing of windows, less pollution through cold starts, reduced fuel consumption on short journeys and less noise from the engine." TEE was developed in cooperation with researchers at Cologne University who carried out numerous trials and computer simulations. The first step was to determine the temperature profile inside the engine during a simulated driving cycle. It takes about 10 minutes for the cooling water to reach a steady operating temperature, while the engine oil takes twice as long and the transmission oil still longer. Volker explained that, once a steady operating temperature had been reached, the engine was switched off and the temperature drop recorded at various locations. For an engine that was fully encapsulated, except for the exhaust manifold and engine mountings, it took 14 to 15 hours for the temperature to drop to 40°C, but only two to three hours for a non-insulated engine. "We calculated that for an annual usage of 12,300km, TEE can generate fuel savings of five percent during the Summer months and eight to nine percent in Winter," added Volker. "Practical trials on the 1.4 litre petrol engine confirmed these findings. A major European car maker is currently studying the feasibility of using TEE for its small diesel engines