Proof-of-Principle Study of the D-Cycle - A Thermodynamic Cycle using Mechanical Compression of a Condensable Vapor.

摘要

In the D-Cycle, a condensing vapor cycle,there is the potential for improved efficiency in power systems. The contract calls for a feasibility study of the D-Cycle using an organic vapor. The working substance must possess the right thermodynamic characteristics;and the attainment of equilibrium between injected liquid and hot vapor must be fast as determined by the time-frame of the compression stroke in a reciprocating engine. The chosen working fluid is 2-2-2trifluoroethanol, CF3CH2OH, 85% mol-fraction with 15% mol-fraction of water -known as Fluorinol 85or F 85. A high pressure pump was developed with variable stroke mechanism. Injection of liquid in mist form into vapor at constant volume is accompanied by temperature decrease and pressure increase under the conditions used. State points at minimum and maximum pressures were determined for dry vapor during compression in a motored reciprocating compressor. The D-Cycle depends on a difference between work of expansion at high temperature and reduction of compression work by injection of liquid. The observed results indicate the feasibility of the cycle using F 85based on published thermodynamic data.