Category The Experimental Analyze Of The Solar Energy Collector

Trestle and bearings

The design of the trestle aimed at the possibility of rotating the parabolic trough about a single axis automatically (east-west or north-south) and about the second axis manually. The possibility of the manual tracking allows the reduction of the IAM (incident angle modifier) by positioning the para­bolic trough with the ideal angle to the sun, especially during the experimental phase.

As identifiable in Fig. 2, the trestle is built up of a frame base of square steel bars with the dimen­sions of 2 m x 2 m, which gives the construction the necessary stability. In the middle of the frame base, a vertical square bar is fixed. With a bearing at the top, the vertical square bar holds the car­rier for the collector body...

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Prediction of the steam-producing power

This model is based on a total of 210 outdoor stagnation experiments, which were carried out between 2003 and 2007 on three different collector types with a total of eight different connection variations (Fig. 1).

Подпись: ETC1c

Подпись: FPC2a Подпись: FPC2b

ETC1a/b

image088 Подпись: FPC3c

FPC2c

The SPP of a collector array depends on numerous parameters such as collector efficiency, system pressure and the piping of the collectors. During the stagnation process, we assume that the two – phase mixture in the collector array has the temperature of saturated steam $s. The theoretical collector performance during stagnation Pstag at the moment of maximum steam spread is calculated as follows:

Подпись:Pstag = GT, stag -Л0 “ a1 (S. )“ a2 (®. “ )2

with

Pstag Theoretical collector performance during stagnation W/m2

GT, stag Effective irradiance...

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Development of solar collectors with FracTherm® aluminium roll-bond absorber

M. Hermann

Fraunhofer Institute for Solar Energy Systems, Heidenhofstr. 2, 79110 Freiburg, Germany
Tel.: +49 7 61 / 45 88 – 54 09, Fax: +49 7 61 / 45 88 – 94 09
michael. hermann@,ise. fraunhofer. de

Abstract

Aluminium becomes more and more interesting as a solar absorber material. One possibility to produce an absorber entirely made of aluminium is given by roll-bond technology which is well established for large-scale series production of e. g. evaporators for refrigerators. This technology offers the possibility to build solar absorbers with high efficiency, since the channel design can be varied without additional costs...

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MEGASOL: a new technology for building big, cheap solar water heating collectors on site

Kerr MacGregor*

MacGregor Solar, 31 Temple Village, Edinburgh, Scotland EH23 4SQ
tel +1875 830 271

* Corresponding Author: kerr @macgregorsolar. com

Abstract

This paper describes a novel method of building large, cheap solar water heating collectors on site. It is based on using synthetic rubber pipes with enhanced thermal conductivity which are squeezed against the underside of an aluminium solar absorber sheet. The collector can easily be built on site using unskilled labour at a relatively low cost. In addition the collectors are freeze-tolerant and can handle corrosive fluids.

1. Introduction

Several attempts have been made (Bartelsen et al, 1999) to use polymers pipes for solar heat collectors. However, these require specially formed absorber plates to encase the pipes...

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