Bestimmung der Wärmeverluste von Receiverrohren mittels transienter Thermografie

Abstract

Thermal heat losses of the receiver tube have a significant influence on the economic viability of solar thermal power plants. It is hence relevant to quantify these heat losses as accurately as possible, in order to replace aged receiver tubes if necessary. However, there is no accurate field measurement method yet available to evaluate the quality of receiver tubes in a parabolic trough power plant. In this study, transient thermography as possible measurement method is introduced. For that purpose, the receiver tube is modeled as a linear, time invariant system with respect to signal processing theory. The quality of the receiver tube can be determined from the frequency response of this system. Methods are therefore developed to compute the frequency response. In a simulation study, different ways to excitate the receiver tube are tested. The focus of this study is to determine how accurately the frequency response can be determined from the resulting temperature functions.