<html><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:10pt"><div class="" style="">Hello,</div><div class="" style="">I need to answer this question please....</div><div class="" style=""><br></div><div class="" style="background-color: transparent;">I'm simulating different types of solar collector. I want to investigate the effect of collector slope on useful energy. When I increase the collector slope of flat plate collector type 1b, the useful energy from collector decreased and the maximum useful energy occurred at 0 deg angle (horizontal), even though the latitude for my region 32 deg, which meaning the useful energy should be increase and not decrease at angles near the latitude angle .</div><div class="" style="background-color: transparent;">but when I used the evacuated tube type 71, the useful energy increased with angle.</div><div class="" style="background-color: transparent;">I
returned to the TRNSYS mathematical reference, flat plate and evacuated tube collectors used the same thermal model and different IAM model. </div><div class="" style="background-color: transparent;">in case of flat plate collectors the IAM for both sky and diffuse radiation depends on the collector slope, if collector slope increase the effective sky and diffuse angle decrease, resulted in decrease the IAM, collector efficiency and useful energy. these results according to TRNSYS mathematical description.</div><div class="" style="background-color: transparent;"> practically, the useful energy should be increase for flat plate as evacuated tube when the collector slope increase. </div><div class="" style="background-color: transparent;">does someone have an idea about this issue? </div><div class="" style=""><br class="" style=""></div><div class="" style="">saja</div><div class="" style=""><span class=""
style=""></span></div><div class="" style="background-color: transparent;"> </div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: verdana, helvetica, sans-serif; font-size: 10pt;" class=""> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;" class=""> <div dir="ltr" class="" style=""> <font size="2" face="Arial" class="" style=""> On Wednesday, May 21, 2014 2:01 PM, saja al-rifai <srhihi2003@yahoo.com> wrote:<br class="" style=""> </font> </div> <br class="" style=""><br class="" style=""> <div class="" style=""><div id="yiv4205167476" class="" style=""><div class="" style=""><div style="color:#000;background-color:#fff;font-family:verdana, helvetica, sans-serif;font-size:10pt;" class=""><div class="" style="">Hello,</div><div class="" style=""><br class="" style=""></div><div style="background-color:transparent;" class="">I'm simulating different
types of solar collector. I want to investigate the effect of collector slope on useful energy. but if I increase the collector slope when I use the flat plate collector type 1b, the useful energy from collector decreased and the maximum useful energy occurred at 0 deg angle (horizontal), even though the latitude for my region 32 deg, which meaning the useful energy should be increase and not decrease at angles near the latitude angle .</div><div style="background-color:transparent;" class="">but when I used the evacuated tube type 71, the useful energy increased with angle.</div><div style="background-color:transparent;" class="">I returned to the TRNSYS mathematical
reference, flat plate and evacuated tube collectors used the same thermal model and different IAM model. </div><div style="background-color:transparent;" class="">in case of flat plate collectors the IAM for both sky and diffuse radiation depends on the collector slope, if collector slope increase the effective sky and diffuse angle decrease, resulted in decrease the IAM, collector efficiency and useful energy. these results according to TRNSYS mathematical description.</div><div style="background-color:transparent;" class=""> practically, the useful energy should be increase for flat plate as evacuated tube if the collector slope increase. </div><div style="background-color:transparent;" class="">does someone have an idea about this issue? </div><div class="" style=""><br class="" style=""></div><div class="" style="">saja</div><div style="color:rgb(0, 0, 0);font-size:13px;font-family:verdana, helvetica,
sans-serif;background-color:transparent;font-style:normal;" class=""> </div></div></div></div><br class="" style=""><br class="" style=""></div> </div> </div> </div> </div></body></html>