An evacuated tube solar collector using therminol D-12 as heat transfer fluid coupled with parabolic trough is studied in this paper. An experimental set-up was constructed to study the performance of evacuated tube collector with therminol D-12 as heat transfer fluid. The parabolic trough is coupled with evacuated tube collector for better performance. In the traditional solar collectors water...

To develop indigenous alternative and renewable energy resources, long-term subsidy programs (1986–1991 and 2000–present) for solar water heaters have been enforced in Taiwan. By the end of 2010, the total installed area of solar collectors had exceeded 2 million square meters. However, over 98% of solar water heaters were used in residential systems for hot water production, with the areas of ...

The cooperative work of the International Energy Agency (IEA) on evacuated collector systems (IEA Solar Heating & Cooling Programme, TASK VI: Performance of Solar Heating, Cooling, and Hot Water Systems Using Evacuated Collectors) covered both experimental and analytical activities on various active solar energy systems, ranging from small domestic hot water to large industrial process heat and...

— Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhousegas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7TWh (1...

Different problems may cause distortion of the rotor, and hence vibration, which is the most severe damage of the turbine rotors. Different techniques have been developed for the straightening of bent rotors. The method for straightening can be selected according to initial information from preliminary inspections and tests such as nondestructive tests, chemical analysis, run out tests and also...

This paper modeled heating air of a room through examining free convection in a 3D chamber. The chamber had cold and hot sources with Tc and Th temperatures, respectively. Its other walls were adiabatic. This study aimed at predicting effect of temperature difference, displacement of hot and cold sources and their aspect ratio on flow field, temperature and heat transfer rate. To conduct the st...

Hybrid installations with respect to renewable energy sources are becoming more popular due the stringent requirements for efficiency of buildings. Therefore, thermomodernization a district-heating substation was proposed. Several scenarios, including different energies (an air–water heat pump versus photovoltaics), investment financing (equity or bank credit), and purposes heating demand (cent...

We point out the priority of our paper (Mahajan et al. 2001) over (Aschwanden et al. 2007) in introducing the term ”Formation and primary heating of the solar corona” working out explicit models (theory as well as simulation) for coronal structure formation and heating. On analyzing the (Aschwanden et al. 2007) scenario of coronal heating process (shifted to the chromospheric heating) we stress...

In this paper, an economic study of solar heat pumps and an investigation of differences between solar heat pumps and conventional heat pumps—based on their performances and energy consumption—are conducted for a residential apartment located in Austin, Texas, USA. Heating in the apartment is provided via a solar heat pump during the cold months of a year. Solar collectors are used to meet the ...

Green bamboo was hydrolyzed over a range of durations at different temperatures. A simple pseudo-homogeneous irreversible first order kinetic model was developed to describe pentosan solubility during steam treatment of green bamboo. To avoid the influence of soluble pentosan during heating process, kinetic parameters were effectively dissolved based on the data in the reacting process. Moreove...