Construction of an Improved Automotive-Steam-Engine Design Per CAL TRANS RFP TA 77-1. Final Report, Milestone VI

摘要

The purpose of this research and development program was to determine the potential thermal efficiency of a small (50 horsepower) automotive-type steam engine. The maximum thermal efficiency demonstrated was 22%, somewhat short of the 27% goal, but believed to be the highest efficiency ever verified with a small Rankine cycle engine. If the development effort is continued there is a good potential for a 27 to 30% thermal efficiency engine system by 1985. The performance of two small passenger cars, one a current model 3000 lb compact car and the second a future 2000 lb vehicle with improved aerodynamics, was estimated for the existing engine with 22% peak efficiency) and for a future 30% peak efficiency engine. The combined driving cycle fuel economy extremes for these conditions ranged from 19.6 to 42.2 mpg. Based on previous emissions tests of experimental steam automobiles and the projected fuel mileages, the exhaust emissions will be considerably lower than the federal research goals of 0.4 grams/mile of HC and NO/sub x/, and 3.4 grams/mile of CO. This has not yet been achieved with internal combustion engines. The primary virtue of the Rankine cycle engine is the low level of exhaust emissions. Another advantage is the ability to burn a wider variety of substitute (non-petroleum) fuels. These studies show that an automotive steam engine might cost only 14% more to produce than a standard spark ignition engine. (ERA citation 07:050804)