CSP Physical Trough Heat Losses

Hello,I have a question regarding the calculation of heat losses (convective and reflective) on the receiver. I understand that they depend on the inlet and outlet temperatures of the HTF, but I'm uncertain about how these temperatures are determined or computed. The simulation results provide four hourly temperature values:

1. Field timestep-averaged inlet temperature (°C)
2. Loop timestep-averaged outlet temperature (°C)
3. Loop timestep-averaged inlet temperature (°C)
4. Loop timestep-averaged outlet temperature (°C)

Could you please clarify which of these temperature values should be used to calculate the heat losses, and could you provide guidance on the calculation process? Additionally, should an initial temperature value be taken into account?Thanks for your support.Veber Ribeiro

Hi Veber,

The heat loss equations are described in Sections 2.1.1 and 2.4.2 of the physical trough model reference manual. For example, see Equations 2.11, 2.26, 2.57, and 2.58 and their descriptions. Additional heat losses are described in Table 8.

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 )

References to this and other papers on SAM's CSP model are on the CSP Publications page: sam.nrel.gov/concentrating-solar-power/csp-publications.html .

Best regards,
Paul.