Dear Kasim,

If I look at the picture, + flow is there. The basic mathematical model equation of the system, shows heat transfer coefficient and fluid capacities Cp is also there. In my opinion, this could be a energy balance, can we include partial differential equation fluid capacities Cp as well as Cf with temperature variance function(x,t)?. If I do this, it will be clear for energy flow between receiver and ambient which is off course there in your equation hg(Tp-Tg). I will suggest one thing, if you please add transfer functions it will be more accurate define with energy balance.

Ashish

Thank you for your response Ashish Thakur , may I ask what you mean by transfer functions?

Regards, Kasim

Dear Kashim,

I said if you consider…

I mean, Verification of an Energy Balance Using Transfer Functions (conduction transfer functions (CTFs), and Simplified Solar Heat Gain Calculations……..

The transfer functions are derived from linearaized system equations by a Laplace transform into frequency domain. The solution yield the fluid temperature Te at the exit of collector module can be represented in frequency domain

Te(s)= Hs . Ys

Te(s)= LT(Te(t)} and Ys = LT{ Y(t)}, s= α+iw (complex functions)

The transfer vactor Hs related to the response of the uncovered collector with the metrological quantities .. Hs is the typical character of transfer function.

Ashish