Comparison of R744 and R134a heat transfer coefficients during flow boiling in a horizontal circular smooth tube

Abstract

The proposal of distributed generation system based on cogeneration Micro-Power Plants (MPP) is presented in the paper. The proposed MPP can operate using local energy resources as well as traditional fuels. The MPP power range can be from few kW up to 100 kW. The primeval fuel energy is better utilized in cogeneration MPP than in power plants producing only electricity. The efficiency of cogeneration MPP can reach the level of 90 %, while in monogeneration power plants the efficiency is below 50 %. 70 to 80 % of the produced energy is used for local heating and 10 to 20 % is used for additional production of electrical energy. The high speed steam turbine using low-temperature evaporation working fluid and an permanent magnet voltage generator directly coupled with turbine are proposed. The different configurations of powerelectronic devices for converting the produced energy to one or three phase 50 Hz waveforms have been discussed.