Issue in the Solar Field for the PTC (CSP)

Hi Paul,
I am working on a project based on the Parabolic trough collector of concentrating solar power. There i have some issue:
The issues in Solar field of the PTC.
1. How to calculate the steady state field pressure drop ( SAM automatic calculate but I do not have any idea how they calculate)?
2. Same as the previous problem how SAM calculate Steady state field pumping power? (Because about Question 1 and 2 there are nothing in the help section of the SAM)
3. Also there are the option in the HTF Flow limit Header design min and max flow velocity for cold and hot header. 
There is the option that I have to put these velocities but I do not know on what basis I should fill these values? 
(I think these values will depend on the velocities of the loops but also if I don't know the diameter of the header pipe then How can I calculate these values?)
I also attach a image there you can see my values for the solar field.
Please solve or clear these things.
best regard's 
Abhishek 
IIT Bombay
 

Hi Abhishek,

The function that calculates the steady state field pressure drop is here: github.com/NREL/ssc/blob/9be2086801b9818c6f9d158d061211065a099336/tcs/csp_solver_trough_collector_receiver.cpp#L1912 .

The equation for state state field pumping power is here:  github.com/NREL/ssc/blob/9be2086801b9818c6f9d158d061211065a099336/tcs/csp_solver_trough_collector_receiver.cpp#L2076

The solar field piping diameter calculations are described in Section 2.5.1 of Wagner, M. J.; Gilman, P. (2011). Technical Manual for the SAM Physical Trough Model. 124 pp.; NREL Report No. TP-5500-51825. ( PDF 3.7 MB ). SAM reports field piping runner diamaters and field piping header diameters in the simulation results, so you could run a simulation to see those values.

In general, if you are not sure of an input variable's value, you can use the default value.

Best regards,
Paul.