Integrated power generation cycle (Kalina cycle) with auxiliary heater and PCM energy storage

Highlights: • A hybrid multi-generation system was developed, validated & assessed. • Integrated solar power plant, Kalina cycle and PCM storage system. • Solar fraction in year is 83.8%. - Abstract: Kalian cycle is a modified Rankine cycle for power generation, that its working fluid is a mixture of ammonia-water instead of pure water and can be driven in higher temperatures comparing to the Rankine cycle. In this study a hybrid Kalina power cycle and solar thermal flat plate collector using phase change material (PCM) as thermal energy storage material is introduced and analyzed. Bandar Aabas (a city in south of Iran), because of its sunny days and use of the Persian Gulf sea water for cooling in the condenser has been selected. The amount of solar fraction in year is 83.8%. This integrated process requires 53.85 GWh heat load during the year that 45.13 GWh of energy per year in the system, is supplied by the sun during the hours of 7–19 and released energy from the PCM during the night from 19.01 to 6.59. Rest of the needed heat load for the integrated system of 8.72 GWh per year is provided with auxiliary heater. By using energy and exergy balance equations, all components were analyzed. According to the results, thermal efficiency of the Kalina cycle is 6.12%. Results of the exergy analyses show 23.21% of the total destroyed exergy in the cycle, occurred in one of the heat exchangers as the main component wasting exergy. Also it was found that most the exergy efficiency is related to the one of the heat exchangers and flash separator with 99.24% and 99.11%, respectively.