Diesel engine waste-heat power cycle

This article demonstrates a possibility for increasing the power output from diesel engines and improving the fuel economy for such engines. This is achieved by employing a power cycle which is driven solely by the engine waste-heat in the cooling water and, also, the exhaust gases. For road engines an organic fluid Rankine cycle is employed. R-12 is evaporated in a boiler, fired by the coolant waste-heat. This is superheated using the exhaust-gases before it is introduced to a turbine where it expands down to an air-cooled condenser. The cycle power output can supplement the base engine power by about 16% of its output. For stationary diesel engines, however, water is used in a steam Brayton power cycle. The released steam, from the cooling water in a flashing chamber, is compressed by a vapour compressor and superheated by the exhaust-gases. This steam is admitted to a turbine coupled to the compressor and the balance of the shaft power is the net output from the cycle. This amounts to about 15·3% of the base engine output. The power cycles employed neither interfere with the operation of the base engine nor deny the application of a turbocharger to it. The thermodynamic analysis for the cycles is given, and the results show the potential for employing such cycles in order to improve the diesel engine's power output by up to 16%.