Parabolic Trough Collectors for Existing District Heating Networks

A Simulation Comparison in TRNSYS

Abstract

Parabolic trough collectors are a suitable renewable heat technology for supplying temperatures above 100 °C and can therefore contribute to the decarbonization of district heating (DH) systems as well as industrial process heat applications [1]. To support the reliable integration of such technologies into system design and planning, validated simulation tools are required. In this work, the performance of a parabolic trough collector field is analysed by comparing TRNSYS simulation results with measurement data from a real plant in Limassol, Cyprus [2].

The comparison is based on high resolution operational and weather data as well as two representative days with different irradiation conditions. The comparison shows that TRNSYS is able to reproduce the characteristic behavior of the collector loop, including supply temperatures and the thermal output. Deviations between simulation and measurements can be explained to identifiable factors such as uncertainties in the cleanliness factor, limited information about soiling, the operational mode of the plant, and tracking errors at the plant.

Despite these uncertainties, the level of correspondence is sufficient for validation purposes. Additional measurement data, particularly on mass flow of the heat transfer fluid (HTF), tracking signals, and cleaning cycles, would further improve the model accuracy and allow for a more detailed validation in future work.