Solar Field Initial Temp Parametrics Output Results Interpretation

Dear SAM users and developers;

I made a parametric simulation "Parametrics" with the "Solar Field Initial Temp (ºC)" as the input variable on my SEGSVI20160515Saracoglu_empirical _2016_11_17.sam model (visit sam.nrel.gov/content/modeling-segs-empirical-model-sam-2016314 for the *.sam file).

Solar Field Initial Temp (ºC)
20
40
60
80
100


I got the results for the following outputs.

Field HTF mass flow rate total (kg/s)
Field HTF temperature average (C)
Field HTF temperature cold header inlet (C)
Field HTF temperature hot header outlet (C)
Cycle thermal startup energy (MWt)

Please find the excel files as attachments.

I try to understand, interpret and criticize the findings or results very well, but I have some difficulties to do that.

For instance:

Field HTF temperature average

HTF temperature average (C) : run(2) (C) Field HTF temperature average (C) : run(3) (C) Field HTF temperature average (C) : run(4) (C) Field HTF temperature average (C) : run(5) (C)
0 50 50 561.794 748.958 936.456
1 50 50 525.983 700.893 876.628
2 50 50 50 655.725 820.358
3 50 50 50 613.277 767.365
4 50 50 50 573.729 717.718
5 50 50 50 536.955 671.288
6 50 50 50 502.881 62.796
7 50 50 50 50 588.745
8 67.455 67.455 67.455 67.455 754.603


Field HTF temperature cold header inlet

Hours since 00:00 Jan 1 Field HTF temperature cold header inlet (C) : run(1) (C) Field HTF temperature cold header inlet (C) : run(2) (C) Field HTF temperature cold header inlet (C) : run(3) (C) Field HTF temperature cold header inlet (C) : run(4) (C) Field HTF temperature cold header inlet (C) : run(5) (C)
0 502.451 502.451 564.577 752.751 941.329
1 502.467 502.467 528.591 704.444 881.172
2 50.248 50.248 50.248 659.046 824.593
3 502.497 502.497 502.497 616.388 771.323
4 502.484 502.484 502.484 576.617 721.399
5 502.475 502.475 502.475 539.635 67.471
6 502.463 502.463 502.463 505.361 631.138
7 502.353 502.353 502.353 502.353 591.595
8 645.623 645.623 645.623 645.623 726.731
9 188.611 188.611 188.611 188.611 194.186
10 276.996 276.996 276.996 276.996 280.888
11 308.931 308.931 308.931 308.931 311.707
12 303 303 303 303 303

Field HTF temperature hot header outlet

Hours since 00:00 Jan 1 Field HTF temperature hot header outlet (C) : run(1) (C) Field HTF temperature hot header outlet (C) : run(2) (C) Field HTF temperature hot header outlet (C) : run(3) (C) Field HTF temperature hot header outlet (C) : run(4) (C) Field HTF temperature hot header outlet (C) : run(5) (C)
0 497.549 497.549 559.012 745.164 931.584
1 497.533 497.533 523.376 697.342 872.085
2 49.752 49.752 49.752 652.404 816.124
3 497.503 497.503 497.503 610.167 763.407
4 497.516 497.516 497.516 57.084 714.036
5 497.525 497.525 497.525 534.275 667.866
6 497.537 497.537 497.537 50.04 624.783
7 497.647 497.647 497.647 497.647 585.896
8 703.477 703.477 703.477 703.477 782.474
9 244.954 244.954 244.954 244.954 250.061
10 310.922 310.922 310.922 310.922 314.235
11 318.032 318.032 318.032 318.032 320.347
12 390 390 390 390 390

Cycle thermal startup energy (MWt)

Hours since 00:00 Jan 1 Cycle thermal startup energy (MWt) : run(1) (MWt) Cycle thermal startup energy (MWt) : run(2) (MWt) Cycle thermal startup energy (MWt) : run(3) (MWt) Cycle thermal startup energy (MWt) : run(4) (MWt) Cycle thermal startup energy (MWt) : run(5) (MWt)
0 0 0 0 0 0
1 0 0 0 0 0
2 0 0 0 0 0
3 0 0 0 0 0
4 0 0 0 0 0
5 0 0 0 0 0
6 0 0 0 0 0
7 0 0 0 0 0
8 0 0 0 0 0
9 0 0 0 0 0
10 0 0 0 0 0
11 0 0 0 0 0
12 869.669 869.669 869.669 869.669 946.685
13 997.495 997.495 997.495 997.495 92.048
14 0 0 0 0 0
15 0 0 0 0 0


My model's Solar Field Inlet Temp (ºC) is 303 and Solar Field Outlet Temp (ºC) is 390. Moreover my model's Solar Field Initial Temp (ºC) is 100.

However, my model's parametric simulation output Field HTF temperature average has some values such as 561.794, 748.958, 936.456, 525.983, 700.893, 876.628.

My model's HTF Fluid is Therminol VP-1. It's Max Optimal Operating Temp is 400.

I do not have any errors, warnings or notices for my model simulation.

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0 errors

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0 warnings

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0 notices

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What did I miss in this parametric simulation?

Were there any decimal point mistakes?

Why did I get approx. 950 ºC and values above 390 ºC and also values above Max Optimal Operating Temp 400 ºC?

I think I have to see some errors on somewhere but I can not guess on which page or sheet.

Can you please interpret and criticize the findings?

Your consideration and help will be very much appreciated.
Best Regards
Burak Omer Saracoglu

Dear SAM users;

I am not sure but I think I find out an answer to some part of my question.

I would like to share to all SAM users.

"SAM will not allow the system to operate at a temperature below the minimum HTF temperature." SAM 2016.3.14 Help Manual

"During the simulation, SAM counts the number of instances that the HTF temperature falls outside of the operating temperature limits in the table below. If the number of instances exceeds 50, it displays a simulation notice with the HTF temperature and time step number for the 50th instance." SAM 2016.3.14 Help Manual

According to these sentences, I think the "Field HTF temperature average", the "Field HTF temperature cold header inlet" and the "Field HTF temperature hot header outlet" may be above the maximum HTF temperature.

After only 50th instance, some notices appear on SAM results.

Hence, the parametric simulation has the same approach.

Although, in real life applications, it is impossible to get temperature values such as 950 ºC, in SAM model simulations it is possible to get very high temperature values (e.g. 950 ºC) above the Max Optimal Operating Temp.

This is the modelling approach of the SAM to real life application (real life to model: modelling approach).

As a result, my current SAM model is appropriate in this sense.

Your consideration and help will be very much appreciated.
Best Regards
Burak Omer Saracoglu