Thermodynamic Performance Analysis Of Graded Regenerative Extraction Organic Rankine Cycle System

Organic Rankine Cycle System is an important way to solve resources underutilized. Organic Rankine Cycle for low temperature waste heat recovery is a viable and more efficient technology. Because it is easy to implement and low technical requirements. ORC for improving the current energy environment has a very important role. Research work of this paper the following aspects:1. On the part of the organic working fluid saturation nature, wet, environmental protection and other properties were compared to explore the effects of evaporating temperature, condensing temperature, superheat, the adiabatic efficiency of the expander basic ORC thermal performance, in particular, obtained through heat has little effect on system performance of this conclusion, with respect to the steam Rankine cycle have a greater advantage.2. Establishment of three modified ORC model- Reheat ORC, ORC heat recovery, heat recovery steam extraction ORC, were explored reheat pressure ratio, return heat, extraction pressure influence on the thermal properties. At the same time, respectively, and basic ORC contrast, found reheat ORC biggest role is to improve the expander work output, thermal efficiency of the heat recovery ORC significantly improved, the heat recovery effect is very obvious, Extraction recuperative ORC expander work output has more substantial decrease of about 39.62%, which is due to the part of the working fluid is used for heat recovery, and the cycle thermal efficiency increased by 7.22%.3. The establishment of a second exhaust heat recovery ORC system model of extraction pressure selection presented three scenarios were calculated for three scenarios analysis, the extraction pressure respectively temperature aliquot point scheme under saturation pressure corresponding to the maximum thermal efficiency. And under optimal suction pressure program, and a heat recovery steam extraction system thermal performance were compared, the thermal efficiency than the first exhaust heat recovery system increased by 4 percentage points. The influence of extraction steam superheat secondary heat recovery system characteristics found superheat less effect on the thermal efficiency.4. Secondary heat recovery system exhaust heat recovery ORC heat recovery efficiency analysis. Exploration programs under optimal suction pressure, evaporation temperature, low-temperature heat source fluid inlet temperature, adiabatic efficiency of the expander heat recovery efficiency. There is an optimal evaporation temperature discover the expander work output and heat recovery efficiency is maximum. With the heat source fluid inlet temperature, exergy efficiency decreases and increases the efficiency of the heat recovery system. When the expander increases the adiabatic efficiency, the system thermal efficiency, exergy efficiency and heat recovery efficiency were increased.