Dear TRNSYS Users:
I would like to compare the performance of some american solar collectors with some european ones. So far I understand, the thermal performance coefficients test for collectors used in Europe and the US are based on diifferent temperature differences ((Ti - Ta) in the US and (Tm - Ta) in Europe).
I would like to convert one type of equation into the other and compare the coefficents. So I Read the TRNSYS Manual, and they convert the equation with the coefficients aM, aN and a2 into an equivalent one with cR(taualpha)n and cRr as coefficients. Then they use some correction factors to change between a function of (Ti - Ta) and a function of (Tm - Ta). But they have still the efficiency equation in terms of cR(taualpha)n/ cavg(taualpha)n and cRr / cavgr.
How can I obtain from these coefficients again the coeffcients aM, aN and a2. It is possible to do that? In other words, it is possible from the coefficients aM, aN and a2 from test based on the temp. difference Ti - Ta) obtain the three coefficients aM, aN and a2 for the efficiency equation based on the temp. difference Tm - Ta
I dont know if I have explained my problem clearly. Thank you in advance for any possible help or comment.
Best Regards
José Luis Corrales Ciganda