Geothermal Energy Systems
Prabin Haloi; Ankit Kumar; Joyshree Dutta; Desire Fadzi Makunike
Abstract
The application of a geofluid is primarily characterized by its geofield conditions and locations. One such application of geofluid is in power generation using suitable energy conversion systems. In this study, a thermodynamic model of a double-flash geothermal power plant (DFGPP) has been developed ...
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The application of a geofluid is primarily characterized by its geofield conditions and locations. One such application of geofluid is in power generation using suitable energy conversion systems. In this study, a thermodynamic model of a double-flash geothermal power plant (DFGPP) has been developed to evaluate its performance which is mainly based on the geofluid of the Puga valley of Ladakh region in the Indian peninsula. The present study investigates the possible use of the DFGPP in the region through application of the exergy tool of the second law of thermodynamics. Under the Puga geofluid conditions, the energy and exergy rates, thermal losses, exergy destruction, and thermal and exergetic efficiencies are evaluated. From the thermal analysis results of the DFGPP, the condenser has the maximum energy loss with 97.08% of the overall loss, followed by low pressure turbine (LPT) and the high pressure turbine (HPT) with minimal energy rate losses of 2.28 % and 0.63 % respectively. However, negligible losses in energy are found to occur in the mixing devices, pump and the fluid separators. The maximum rate of exergy destruction occurs in the LPT with 38.95 % and least in the low pressure separator (LPS). The DFGPP operated with energy and exergy efficiencies of 9.52% and 48.39% approximately, producing a net output work of 3.9 MW. The overall cycle exergy destruction is found at 5.4% of the total energy losses. The use of DFGPP systems in the Puga geofield can be a suitable option in power generation.
Geothermal Energy Systems
Hiba Mudhafar Hashim; Firas ABED
Abstract
Geothermal energy is one of the important sources of renewable energy, so researchers are greatly interested in this type of energy. One of the advantages of this type of energy is its use to heat or cool buildings because the ground temperature is fairly constant throughout the year. The research focuses ...
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Geothermal energy is one of the important sources of renewable energy, so researchers are greatly interested in this type of energy. One of the advantages of this type of energy is its use to heat or cool buildings because the ground temperature is fairly constant throughout the year. The research focuses on understanding how soil depth affects the temperature difference, the rate of heat transfer, and the overall performance of the system in Baghdad, Iraq, throughout the year by conducting a mathematical test for the ground heat exchanger and determining the number of appropriate requirements during the study to reach an equation that simulates the distribution of temperatures at depth and time. The software package (CFD ANSYS FLUENT) version 17 was used for numerical analysis. The results showed that the heat transfer rate from air to soil for cooling purposes reached its highest value of -1375 watts during July at a depth of 6 m. As for heating purposes, the maximum value during January reached 579 watts at a depth of 10 m and 499 watts at a depth of 6m. Earth air heat exchanger effectiveness was highest possible at depths of 4 and 5 m, ranging from 0.9 to 0.92 over the year. The highest value of 0.98 for the exchanger effectiveness appeared during March. The results showed good agreement between the mathematical and numerical analysis and comparison with other studies, as the percentage of deviation ranged from 1.7% to 3.6% for depths from 1 m to 10 m.
Geothermal Energy Systems
H. Mohamed; E. Bani-Hani; M. EL Haj Assad
Abstract
A thermodynamic analysis based on first law of thermodynamics of organic Rankine cycle (ORC) was presented to find out effect of organic fluid selection on the cycle efficiency and power output.Different configurations of ORCs with and without Internal Heat Exchanger (IHE) were used. The criteria for ...
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A thermodynamic analysis based on first law of thermodynamics of organic Rankine cycle (ORC) was presented to find out effect of organic fluid selection on the cycle efficiency and power output.Different configurations of ORCs with and without Internal Heat Exchanger (IHE) were used. The criteria for choosing the optimum working fluid were discussed and many different organic fluids were compared in terms of thermal efficiency and power output. The results showed that higher efficiencies were obtained for ORCs with IHE configuration, and the organic fluid R123 had the most favorable performance for which the thermal efficiency of ORC was 14.2 and 13.28 with and without IHE, respectively. Moreover, the work output of ORC cycle was about 50 kJ/kg which was the highest when using R123 as an organic fluid.