Design of a Test Rig and its Testing Methods for Rotation and Expansion Performing Assemblies in Parabolic Trough Collector Power Plants

The present master’s thesis deals with the design of a new test rig for the investigation of durability and failure mechanisms of flexible pipe connections – so called Rotation and Expansion Performing Assemblies (REPAs) –, which are utilized in Parabolic Trough Collector power plants. Said assemblies compensate for the motion of the absorber tubes relative to the fixed piping of the header connection. The work focusses on the test rig’s design in view of a realistic simulation of all loads a REPA is exposed to in commercial applications. To achieve this, all possible requirements of the components, which are supposed to endure a lifetime of up to 30 years in power plants, are depicted. A literature research is carried out in order to investigate and evaluate existing test rigs for REPAs or their single components. By means of the findings, a specification sheet is derived. The test rig is composed of two main assemblies. On the one hand, a Kinematics Unit is used to reproduce the cyclic rotational and translational motions of a Parabolic Trough Collector. On the other hand, an HTF cycle (Heat Transfer Fluid cycle) conduces to set up pressure, temperature and flow rate circulating through the test specimens. The main part of the thesis contributes to the integration of the externally designed Kinematics Unit into the HTF cycle – taking into consideration realistic operation conditions and a complete and precise measurement of all parameters. Special emphasis is put on an accurate acquisition of the mechanical loads the test objects have to cope with. As a result of this work, a test rig is erected enabling realistic endurance tests of two serially connected REPAs in less than three months. The hydraulic properties are adjustable in terms of mass flow (6−60 m3/h), pressure (up to 40 bars) and temperature (up to 450 °C). The investigations can be tailored to customized applications of the REPA concept (Ball Joint Assemblies or Rotary Flex Hose Assemblies) and the collector geometry (e.g. focal length)

Wirtschaftsordnung und Unternehmen im Nationalsozialismus. Neuere Forschungen zur Wirtschaftsgeschichte des Nationalsozialismus

Abelshauser W, Hesse J-O, Plumpe W. Wirtschaftsordnung und Unternehmen im Nationalsozialismus. Neuere Forschungen zur Wirtschaftsgeschichte des Nationalsozialismus. In: Abelshauser W, Hesse J-O, Plumpe A, eds. Wirtschaftsordnung, Staat und Unternehmen. Neue Forschungen zur Wirtschaftsgeschichte des Nationalsozialismus ; Festschrift für Dietmar Petzina zum 65. Geburtstag. Essen: Klartext-Verlag; 2003: 9-16

Test loop for inter-connections of parabolic trough collectors

The Spanish Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT) through its Plataforma Solar de Almería (PSA), started a program for testing outdoor every individual component of parabolic trough collectors (PTC), i.e. structure, mirrors, absorber tubes, etc., reproducing real solar conditions as well as in laboratories using accelerated aging chambers or appropriate test loops. A very important part pending of testing in an ad-hoc facility were the collectors’ inter-connections (ball joints, flexible hoses and hybrid interconnections). In that sense, CIEMAT-PSA and the German Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) agreed to erect a common test bench at PSA. The so called Rotation and Expansion Performing Assembly (REPA) enables specific test as well as accelerated full lifecycle tests under realistic conditions, using silicone or mineral oil based HTFs at temperatures up to 450°C. It was erected and commissioned at PSA and it will start its operation late 2017: The REPA test facility is the result of merging CIEMAT activities in task 14.4 of the European project SFERA-II and DLR activities within the work package 6 of the national German project StaMeP. In a solar power plant with parabolic trough collector (PTC), one of the main technical constraints in the solar field is dealing with the absorber tubes thermal expansion and collectors rotation motion. The non alignment between the collector focal line and the rotation axis is a key point in the construction of this type of solar field. As consequence, the connection interface between the receiver tubes of adjacent PTC in one side and between headers and both loop ends in the other, must be accomplished using elements tested in real conditions able of absorbing that stress