Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be util...Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.展开更多
A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the s...A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the system with time under the real weather has been given. The system efficiency and the relation between efficiency and temperature have been calculated. The test result shows that the system has the advantages of high collecting temperature and not obvious variety of the collecting efficiency with the operating temperature. Therefore, this collector is a quite ideal medium temperature solar collector.展开更多
文摘Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.
基金Acknowledgments This work is supported by the National Natural Science Foundation of China （No.50576004） and National ＂863＂ Hi-Tech Development Program of China （No.2007AA05Z433）.
文摘A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the system with time under the real weather has been given. The system efficiency and the relation between efficiency and temperature have been calculated. The test result shows that the system has the advantages of high collecting temperature and not obvious variety of the collecting efficiency with the operating temperature. Therefore, this collector is a quite ideal medium temperature solar collector.
