2014 A cooled cubic cavity receiving a non uniform concentrated solar radiation is modelized, using the diffuse and semi-gray surface hypothesis and the net radiation method equations. Two more equations corresponding to the heat transfer to a cooling fluid permit to define a heat balance. Thus at thermal equilibrium, net fluxes and temperatures inside the cavity are calculated. An air-cooled s...

2014 This report is an account of the design, checkout and solar testing of a cavity receiver using metal gas-in-tube heat exchangers. The design represents a scale model of a Brayton cycle solar electric plant receiver. The program span from initiation of design to test completion was 32 months. The DOE-Central receiver test facility was utilized in this inaugural test. Tests involved controll...

We examine the effects of including effects of both protons and electrons on the heating of the fast solar wind through two different approaches. In the first approach, we incorporate the electron temperature in an MHD turbulence transport model for the solar wind. In the second approach, we adopt more empirically based methods by analyzing the measured proton and electron temperatures to calcu...

The paper presents two designs of combined prismatic-parabola-cylindrical stationary concentrators. They reach 8.4X and 10.4X concentration levels for nonsymmetrical and symmetrical concentrators correspondingly and can be used with solar cells for electricity and heat generation. ©2010 Optical Society of America OCIS codes: (220.1770) Concentrators; (220.4298) Nonimaging optics; (220.2740) Geo...

Abstract Solar wind protons undergo significant heating during the expansion of solar and turbulence plays an important role in this process. It is believed that energy injected from energy-containing range into inertial then transferred to dissipate heat eventually. However, injection process heliosphere remains unclear. Here we analyze We utilize Helios 2 Ulysses measurements fast at differen...

The exploitation of natural ventilation is a good solution to improve buildings from an energetic point of view and to fulfill the requirements demanded by the thermohygrometric comfort and the air quality in enclosed spaces. Some past researches demonstrated how some devices, useful to this purpose, follow the principles of solar chimneys and are able to move air masses while exploiting the Ar...

Solar energy is a good option among renewable energy resources due to its easy availability and abundance. The simplest and most efficient way to utilize solar energy is to convert it into thermal energy and this can be done with the help of solar collectors. The thermal performance of such collectors is poor due to less heat transfer from the collector surface to air. In this work, experimenta...

Renewable energy supplies are steadily gaining increasing importance in all the countries. In particular, solar energy, being non-polluting, clean and inexhaustible, has received wide attention among scientists and engineers. Though there are many advantages, an important factor is that solar energy is time dependent energy source with an intermittent character. Hence some form of thermal energ...

The choice of heat transfer fluids has significant effects on the performance, cost and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based on a new figure of merit capturing the combined effects of thermal storage capacity, convective heat transfer characteristics and hydraulic performance of the fluids. Thermal s...

Ten growing heifers were either exposed to or protected from solar radiation, offered a diet of either high (H) or low (L) ME, and fed either in the morning or afternoon during a hot summer. Heifers that consumed the H diet had a greater water intake, DMI, metabolizable energy intake, energy expenditure, and retained energy than heifers that consumed the L diet. Solar radiation did not have an ...