????? 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?

?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?

M. Shoaib Ahmed Khan
Islamabad, Pakistan
shoaibkhan0759 at yahoo.com