<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym18_1_1458580231641_7110"><br></div><div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym18_1_1458580231641_7136" style="display: block;"><div style="font-family: HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_ym18_1_1458580231641_7135"><div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_ym18_1_1458580231641_7134"><div class="y_msg_container" id="yui_3_16_0_ym18_1_1458580231641_7149"><div id="yiv7478804760"><div class="yiv7478804760yqt1688659778" id="yiv7478804760yqtfd24018"><div id="yui_3_16_0_ym18_1_1458580231641_7148"><div style="color:#000;background-color:#fff;font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;" id="yui_3_16_0_ym18_1_1458580231641_7147"><div class="yiv7478804760yahoo_quoted" id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5182" style="display:block;"><div id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5181" style="font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5180" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div class="yiv7478804760y_msg_container" id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5208"><div id="yiv7478804760"><div id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5207"><div id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5206" style="color:#000;background-color:#fff;font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div dir="ltr" id="yiv7478804760yui_3_16_0_1_1458067212438_6693"><span id="yiv7478804760yui_3_16_0_1_1458067212438_6692"> I am trying to simulate type 71. I am using default values of ao = 0.70, a1 = 10 kJ/hr.m2.K and a2 = 0.03kJ/hr.m2.K2 of type 71. Default area of collector is 1 m2. So for the given tested flow rate of 3kg/hr.m2, the collector pump flow rate becomes 3 kg/hr (tested flow rate x area of collector) which is quite low as compared with other evacuated tube collectors. When I try to calculate efficiency at any particular instant during day through following two equations, it is not equal at all. Can you please help me with this?<br clear="none"></span></div><div dir="ltr" id="yiv7478804760yui_3_16_0_1_1458067212438_6859"><span id="yiv7478804760yui_3_16_0_1_1458067212438_6692"></span><br clear="none"></div><div dir="ltr" id="yiv7478804760yui_3_16_0_1_1458067212438_6862"> <img class="yiv7478804760ymail-preserve-class yiv7478804760inline-image-guid-4edb7e5d-faa7-c09b-3b29-fe434075bbc3 yiv7478804760rte-inline-saved-image img-overlay-selected" id="yiv7478804760yui_3_16_0_1_1458067212438_7044" src="cid:ab5c67cb-7435-d8de-a44f-9e541c0e4628@yahoo.com" alt="Inline image" style="width:100%;max-width:374px;max-height:155px;" data-id="f484f9ba-a06d-423c-bc0e-1103691b863a"></div><div dir="ltr" id="yiv7478804760yui_3_16_0_1_1458067212438_7261">One more thing,for evacuated tube collector type 1288, flow rate at test conditions is not given for which values of ao, a1 and a2 are given. Can you provide me that flow rate at test conditions?<br clear="none"></div><div dir="ltr" id="yiv7478804760yui_3_16_0_ym18_1_1458580231641_5234"><br clear="none"><span style="font-size:11.0pt;line-height:107%;">
</span></div><div id="yiv7478804760yui_3_16_0_1_1458067212438_6763"></div><div class="yiv7478804760signature" id="yiv7478804760yui_3_16_0_1_1458067212438_6662"><i id="yiv7478804760yui_3_16_0_1_1458067212438_6661">M. Shoaib Ahmed Khan<br clear="none">Islamabad, Pakistan<br clear="none"></i></div><div class="yiv7478804760signature" id="yiv7478804760yui_3_16_0_1_1458067212438_6662"><i id="yui_3_16_0_ym18_1_1458580231641_7225">shoaibkhan0759@yahoo.com</i></div></div></div></div><br clear="none"><br clear="none"></div> </div> </div> </div></div></div></div></div><br><br></div> </div> </div> </div></div></body></html>