Experimental study of converging-diverging nozzle to generate power by Trilateral Flash Cycle (TFC)

Recovering heat from low grade heat resources for producing power is of high demand and interest. For this purpose, the an experimental study of converging-Diverging nozzle to generate power in Trilateral Flash Cycle (TFC) is investigated in this paper. In the proposed system, performance of a designed and manufactured to recover the heat and convert the heat energy to mechanical energy has been investigated. In this system, Isopentane, which is selected to be the working fluid due to its low boiling temperature, is heated by low temperature hot water and pumped through a two-phase flow nozzle, where the energy conversion takes place. In the nozzle, part of the liquid evaporates and the accelerated mixture exits the nozzle and impacts on a Pelton turbine bucket shape target. The high potential of power generation from low temperature heat resources is demonstrated through theoretical analysis. Generated force of high speed flow out of two phase nozzle has been experimentally measured in lab scale test rig and isentropic efficiency of the nozzle has been calculated based exit speed of the working fluid. Around 45% isentropic efficiency has been shown From the test results. In addition, 1.5 N-4 N force increase was detected by increasing temperature of working fluid from 30 degrees C to 70 degrees C correspondingly. The results of this experiment can be applied on a power plant waste heat as a case study, where the increased energy conversion efficiency is demonstrated on the binary cycle.