Design, construction, and testing of a parabolic trough solar concentrator for hot water and low enthalpy steam generation

This paper reports the design, construction, and evaluation of a solar parabolic trough concentrator (PTC) with a rim angle of 45°, a length of 4.88 m, and an aperture area of 5.8 m2. The PTC is made of aluminium in such a way that both the manufacturing and assembly processes do not require complicated technology or skilled labour. Since the PTC is for low enthalpy steam generation and hot water, it is designed with an unshielded receiver and without a glass cover in order to reduce both production and transportation costs. A finite element stress analysis is conducted to determine the mechanical behaviour of the PTC under various simulated wind loads on the structure. A simple solar tracking system is employed when it is oriented in a North-to-South direction. The optical efficiency of the collector is also reported. Said efficiency depends on the optical properties of the materials involved, the geometry of the collector, and the various imperfections arising from the construction of the collector. The thermal performance of the PTC was determined according to the Standard ASHRAE 93-1986 (RA 91). Peak efficiencies close to 60% were obtained.