Experimental Methodology and Thermal Loss Tests on Small Size Absorber Tubes for Solar Applications

Abstract

Since thermal energy for residential applications is a relevant part of the entire energy demand, solar technologies could play an important role in decreasing fossil fuel consumption. A novel small parabolic trough collector matched with a storage system is developed to satisfy heating and required hot water demand for a single house. A new receiver concept is designed and a prototype is realized using two coaxial tubes (three spattered layers). A covering glass with vacuum inside completes the high tech design. Because of numerous innovations including the small size, a specific off-Sun measurement procedure is set up with the aim of evaluating the real thermal loss and direct heating of the absorber by Joule effect. A novel test procedure is proposed for the one-end absorber. The receiver performance results are reported under vacuum conditions and with air at ambient pressure.

Experimental Characterization of Commercial Scroll Expander for Micro-Scale Solar ORC Application: Part 1

“…Micro-ORCs powered by solar energy represent one of the most effective tools for distributed generation and PED (Positive Energy District). Over the years, many advances have been made, both in the field of solar collectors [12][13][14] and in thermal storage for residential applications [15]. All of this makes micro-ORC systems even more attractive.…”

Structured Light Profilometry on m-PTC

“…In fact, considering a defect of the same size on the surface of a micro-PTC collector and on a conventional PTC mirror will result in a greater loss of energy on the smaller concentrator, because it affects a larger fraction of the total area of the receiver. In the current testing phase for this technology [14][15][16][17], a fundamental parameter to be experimentally determined and calculated is the optical efficiency of the system. It represents the upper limit that overall efficiency can be reached in the absence of thermal losses.…”

“…In the current testing phase for this technology [14][15][16][17], a fundamental parameter to be experimentally determined and calculated is the optical efficiency of the system. It represents the upper limit that overall efficiency can be reached in the absence of thermal losses.…”