The present work describes software SOLEEC （copyright 03-2012-070510302900-01 Mexico）, a numerical tool for PTC （parabolic trough collector） designing. Software SOLEEC is divided into two main parts. The first one...The present work describes software SOLEEC （copyright 03-2012-070510302900-01 Mexico）, a numerical tool for PTC （parabolic trough collector） designing. Software SOLEEC is divided into two main parts. The first one allows solar resource assessment for a specific place on the Earth. The computation and assessment can be done for a specific day on the year, for one specific month and the monthly averages along the year. The last one gives annual charts such as： solar constant, Earth declination, insolation hours, and sunrise and sunset hours. The second part has four different execution options for PTC designing, that is, using options one and two user can get five different designs based on receiver outer diameter evaluating solar radiation data along the full year or only one solar radiation value （monthly）, on the other hand options three and four were developed to compute the thermal evaluation for an operating collector for twelve solar radiation values （annually） or a specific month computation, respectively.展开更多
Solar and biomass are both renewable energy resources.Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources.However the costs o...Solar and biomass are both renewable energy resources.Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources.However the costs of power from a biomass power generation plant depend greatly on the availability and quality of the biomass resource.The commercialization of solar alone thermal power generation is hindered by its high initial investment and low thermal efficiency.In this paper,a concept of integrating solar into a biomass power generation system is put forward.In the system the oil heated by a parabolic trough solar field is used to replace the extraction steam to preheat the feed water(entering a biomass boiler) and the previous extraction steam thus saved can continue to do work in the lower stages of turbine.The performance of the hybrid system with different replacements is analyzed and compared through two typical solar aided biomass generating units.The results show that the integration not only reduces the consumption of biomass fuel(at the same generation capacity) but is also proved to be an efficient way to convert solar thermal energy into power.The results also show that with the same solar aperture area,the higher the grade of the replaced extraction steam,the better the thermal performance and economy.展开更多
In this paper,we present a three dimensional numerical investigation of heat transfer in a parabolic trough collector receiver with longitudinal fins using different kinds of nanofluid,with an operational temperature ...In this paper,we present a three dimensional numerical investigation of heat transfer in a parabolic trough collector receiver with longitudinal fins using different kinds of nanofluid,with an operational temperature of 573 K and nanoparticle concentration of 1% in volume.The outer surface of the absorber receives a non-uniform heat flux,which is obtained by using the Monte Carlo ray tracing technique.The numerical results are contrasted with empirical results available in the open literature.A significant improvement of heat transfer is derived when the Reynolds number varies in the range 2.57×104≤ Re≤ 2.57×105,the tube-side Nusselt number increases from 1.3 to 1.8 times,also the metallic nanoparticles improve heat transfer greatly than other nanoparticles,combining both mechanisms provides better heat transfer and higher thermo-hydraulic performance.展开更多
文摘The present work describes software SOLEEC （copyright 03-2012-070510302900-01 Mexico）, a numerical tool for PTC （parabolic trough collector） designing. Software SOLEEC is divided into two main parts. The first one allows solar resource assessment for a specific place on the Earth. The computation and assessment can be done for a specific day on the year, for one specific month and the monthly averages along the year. The last one gives annual charts such as： solar constant, Earth declination, insolation hours, and sunrise and sunset hours. The second part has four different execution options for PTC designing, that is, using options one and two user can get five different designs based on receiver outer diameter evaluating solar radiation data along the full year or only one solar radiation value （monthly）, on the other hand options three and four were developed to compute the thermal evaluation for an operating collector for twelve solar radiation values （annually） or a specific month computation, respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos 51025624, 51006033)the National Basic Research Program of China ("973" Program) (Grant No 2009CB219801)Foundation of North China Electric Power University
文摘Solar and biomass are both renewable energy resources.Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources.However the costs of power from a biomass power generation plant depend greatly on the availability and quality of the biomass resource.The commercialization of solar alone thermal power generation is hindered by its high initial investment and low thermal efficiency.In this paper,a concept of integrating solar into a biomass power generation system is put forward.In the system the oil heated by a parabolic trough solar field is used to replace the extraction steam to preheat the feed water(entering a biomass boiler) and the previous extraction steam thus saved can continue to do work in the lower stages of turbine.The performance of the hybrid system with different replacements is analyzed and compared through two typical solar aided biomass generating units.The results show that the integration not only reduces the consumption of biomass fuel(at the same generation capacity) but is also proved to be an efficient way to convert solar thermal energy into power.The results also show that with the same solar aperture area,the higher the grade of the replaced extraction steam,the better the thermal performance and economy.
文摘In this paper,we present a three dimensional numerical investigation of heat transfer in a parabolic trough collector receiver with longitudinal fins using different kinds of nanofluid,with an operational temperature of 573 K and nanoparticle concentration of 1% in volume.The outer surface of the absorber receives a non-uniform heat flux,which is obtained by using the Monte Carlo ray tracing technique.The numerical results are contrasted with empirical results available in the open literature.A significant improvement of heat transfer is derived when the Reynolds number varies in the range 2.57×104≤ Re≤ 2.57×105,the tube-side Nusselt number increases from 1.3 to 1.8 times,also the metallic nanoparticles improve heat transfer greatly than other nanoparticles,combining both mechanisms provides better heat transfer and higher thermo-hydraulic performance.
