User-Defined Power Block

Hi Bernardo,

SAM's CSP models assume that the power cycle HTF is the same as the solar field HTF, so the specific heat Cp value in that equation is from the solar field HTF property table.

For models with thermal energy storage (TES), the TES storage medium may be different from the solar field HTF. In that case, during discharge of heat from the TES, the heat is transferred from the storage medium to the solar field HTF and then to the power cycle.

Best regards,
Paul.

Hi Paul.
But HTF temperature and mass flow is still the power cycle values, right?
And if the power cycle HTF is different from the solar field HTF? We need to assume that cp is the same?

Best regards,
Bernardo.

Hi Bernardo,

SAM assumes that the power cycle HTF is the same as the solar field HTF.

Best regards,
Paul.

Hi Paul.
The normalized "HTF m" on the UDPC table is realated to the power cycle HTF right? As we give the normalized value, how SAM calculate the absolute value since we don't give the design mass flow rate?
In the time series results, why the "PC HTF mass flow rate" pertain to solar field HTF?

Best regards,
Bernardo.

Hi Paul.
Just to be clear: on the User-Defined Power Block, the value of "normalized HTF mass flow rate" refers to the HTF of the power cycle, right? Also the value of  "Cycle design HTF mass flow rate" from General Design Parameters refers to the HTF of the power cycle?
So, the normalized value is calculated by dividing the mass flow from a certain point by "Cycle design HTF mass flow rate"? Is that correct?

I realized that I was making that wrong after checking the "PC HTF mass flow rate" in the Time Series results, because it seems that the result is the multiplication of "Normalized HTF mass flow rate" times "Cycle design HTF mass flow rate"...

Could you clarify me?

Best regards,
Bernardo.

Hi Bernardo,

Yes, the "cycle design HTF mass flow rate" under "General Design Parameters" on the Power Cycle page refers to the HTF in the power cycle.

The normalized values under "Variable information calculated from power cycle data in table below" are normalized to the design value.

Best regards,
Paul.