فهرست مطالب m. abdolalipouradl

The use of geothermal energy is expanding worldwide due to its durability, environmental benefits and high power production. One of the most common types of geothermal systems is the Double Flash (DF) cycle. Typically, a significant amount of energy is lost through the saturated liquid of the second separator in this configuration. With the approach of using this energy, a DF–Organic Rankine Cycle (ORC), a novel DF–CO2 Transcritical Rankine Cycle (CTRC) and a novel DF–ORC–CTRC are investigated from energy and exergy viewpoints. Then, for configurations, a comprehensive parameter analysis and single-objective optimization were performed for configurations with the criterion of net output power maximization. The results indicated that all three combined configurations outperformed the double flash cycle in terms of the first and second laws of thermodynamics. Among the investigated cycles, the DF–ORC–CTRC demonstrated the best performance, with net output power, energy efficiency, and exergy efficiency calculated as 26313 kW, 20.54%, and 64.46%, respectively.

Nowadays, the economic, environmental, and technical advantages are a suitable approach for multigeneration systems, and the approach of using waste heat for these systems shows its value more than ever. In this study, a multigeneration system consists of a supercritical carbon dioxide (S-CO2) Brayton, Organic Rankine Cycle (ORC), Proton Exchange Membrane (PEM) electrolyzer, and Reverse Osmosis (RO) system. First, energy and exergy analysis has been done on the proposed system, then a parametric study has been performed on this proposed system and finally, it has been optimized from maximum output power viewpoint. The optimization results also show that 252366 kW, 43.1%, 58.37%, 12.13 kg/hr, and 55.52 kg/s, respectively, are calculated for the values of generated power, thermal and exergy efficiencies, hydrogen production, and produced fresh water. Moreover, the new multi-generation system that uses supercritical CO2 in Bryton has better thermal efficiency compared to the previous study.

Gaynarje spring is one of the hottest springs in the world and is located around Meshginshahr in northwest of Iran. Because of the water at temperature of 82 ºC, it is not appropriate to use this mineral water for swimming and bathing. In this study, in addition to lowering the water temperature to the appropriate swimming temperature (29 ºC), the hot water is used for power and natural gas production in a combined cycle based on Organic Rankine Cycle (ORC) and LNG cold. The proposed configuration has been studied thermodynamically and optimized for important performance parameters. For this purpose, mass, energy and exergy equations were developed for components and the whole system. Also, performance parameters were calculated. For achieving the best results, several working fluids are examined for the ORC. According to the obtained results R245fa as an ORC working fluid has the best performance from the thermodynamic viewpoint. Also, for optimum condition of the cogeneration cycle, net output power, natural gas production, thermal and exergy efficiencies were calculated to be 524.9 kW, 1.352 kg/s, 24.11 and 48.99%, respectively. The parametric study is also indicated that the performance parameters have optimum values with respect to the evaporator temperature.

In Iran, Sabalan geothermal power plant has been utilized with two wells having different and mass flow rates and thermal properties. In this study, in order to achieve the maximum power, four new configures; a single flash-binary, a double flash (I)–binary, a double flash (II)–binary and a triple flash-binary cycles were examined. These four configurations were initially investigated considering the effective parameters of energy and exergy analysis, and then optimization was performed using three working fluids. The results show that in the optimum state, the double flash (II)–binary using isobutane shows better results compared to the other three configurations. Furthermore, for the optimum case, the net power of 23084 kW, the thermal efficiency of 19.74%, the exergy efficiency of 75.7%, and the exergy destruction rate of 6250 kW were obtained which show an improvement in terms of energy and exergy for the Sabalan geothermal power plant compared to the previous studies.