Automotive engine with urea injection to exhaust system has fuel return pipe surrendering heat to urea tank

摘要

An internal combustion engine has a cylinder with a combustion chamber discharging exhaust gases via an outlet valve to an exhaust system (4). Fuel is measured and introduced to the combustion chamber by an injection valve (18). Excess fuel not injected is returned by a pipe to a fuel tank. The engine has a urea tank (40) with a tube (41) to an injection valve (54) that releases urea into the exhaust system. The return fuel pipe (44) surrenders heat to the urea tank (40) contents.