An experimental study on a cylindrical-conical cavity receiver for the parabolic dish collector.

Solar thermal energy is a promising solution to the environmental and energy demands issues which the world is faced with them. Among all the solar thermal collectors and solar towers used in this field, parabolic dish collectors are one of the preferable options for researchers due to their high working temperature range and high thermal performance. It has been proved that cavity receivers in solar dish collectors are the best way to achieve the best thermal performance. The main concern in the cavity receivers is their thermal efficiency enhancement by employing different geometries. The hybrid geometry of cylindrical-conical can be used to achieve the high pressure drop and low thermal efficiency of conventional cylindrical and conical cavity receivers, respectively. Furthermore, using proper insulation for the cavity receiver helps to performance enhancement of the dish collector. Ceramic fiber insulation can be suitable for this purpose due to its good thermal properties and fewer environmental issues. Hence, in this study, the objective of efficiency enhancement of parabolic dish collector is followed by utilizing a cylindrical-conical cavity receiver equipped with the fiber ceramic insulation. The results show that ceramic fiber is better insulation than the common mineral wool insulation and can enhance thermal performance by 5.03% on average. In addition, the maximum, average, and minimum thermal efficiencies of the cylindrical-conical cavity receiver by using the ceramic fiber insulation and water as the working fluid were obtained up to 38.77%, 35.19%, and 32.66%, respectively.

A review on solar-powered cooling systems coupled with parabolic dish collector and linear Fresnel reflector.

Solar energy is the most sustainable and free source to manage the world energy demand. One aspect of solar-driven energy supply can be observed in cooling systems. Recently, solar energy-based cooling systems have received many attentions. Solar cooling systems utilizing solar collectors, as the renewable and sustainable-based solution, have the good potentials to overcome the challenges associated with consumption of fossil fuels. In this study, the recent advances about the potentials of dish collectors and linear Fresnel reflectors for the usage in the cooling systems are reviewed. In addition, the solar-powered conventional absorption chiller and cryogenic systems are investigated. Hybrid cooling solar systems and solar-based combined cooling, heating, and power systems are also studied. The hydrogen production in cooling integrated systems and cold thermal energy storage are discussed. In each section, in addition to general description of the system, some explanations about the thermodynamic and economic aspects of the systems are provided. Finally, the main results of the review are summarized and based on the available gaps between the literatures, some suggestions are provided for the future studies. It was found that using solar dish collectors in a hybrid system, designed for the freshwater and LNG production, causes carbon dioxide emissions reduction by 40%, and also increases freshwater and LNG production by 95% and 4.7%, respectively. In the hybrid trigeneration solar-biomass power plants, using the linear Fresnel reflector leads to 29% save in biomass and land.