In Europe for the measurement of the thermal efficiency of a solar collector, the Standard EN 12975-2 [1] is followed. However, in the literature is also recognized the opportunity to obtain faster and cheaper evaluations of this parameter. In order to give an answer to this request, a modified test equipment for the evaluation of the thermal performance of solar collectors, based on EN 12975-2 [1], is proposed. The standard procedure followed in Europe requires expensive equipments and time consuming procedures; at the same time the required operating conditions are difficult to be set up. Starting from the basic scheme for the steady-state method, a new equipment for the measurement of the instantaneous efficiency has been realized. The equipment allows a fast evaluation of the performance in real environmental conditions. The main difference is in the procedure used to fix the different test conditions. Although the accuracy of some measurements are not totally conforming to EN 12975-2 [1], the results are quite comparable and the reliability of the procedure and of the equipment is demonstrated.
A MODIFIED EN 12975 TEST FACILITY FOR THE MEASUREMENT OF THE ISTANTANEOUS EFFICIENCY OF SOLAR THERMAL COLLECTORS
CASANO, Giovanni;PIVA, Stefano
2012
Abstract
In Europe for the measurement of the thermal efficiency of a solar collector, the Standard EN 12975-2 [1] is followed. However, in the literature is also recognized the opportunity to obtain faster and cheaper evaluations of this parameter. In order to give an answer to this request, a modified test equipment for the evaluation of the thermal performance of solar collectors, based on EN 12975-2 [1], is proposed. The standard procedure followed in Europe requires expensive equipments and time consuming procedures; at the same time the required operating conditions are difficult to be set up. Starting from the basic scheme for the steady-state method, a new equipment for the measurement of the instantaneous efficiency has been realized. The equipment allows a fast evaluation of the performance in real environmental conditions. The main difference is in the procedure used to fix the different test conditions. Although the accuracy of some measurements are not totally conforming to EN 12975-2 [1], the results are quite comparable and the reliability of the procedure and of the equipment is demonstrated.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
