Validation of the library components

The validation of the models is necessary to ensure that the calculated results are valid. Furthermore it is to proof what differences consist due to the assumptions made in the models.

The different components were validated mainly with calculation results of other software. The comparisons showed good agreement of the new models with the references for steady state simulation. The validation of the receiver model has been done with calculation results for one day from the DLR TRNSYS simulation model. The comparison (see Fig. 3) showed a difference in the absolute values but it could be shown that the model has the same behaviour as can be seen by the calculation of the power that reaches the boiler.

image174

Fig. 3: Comparison results for the power Prec leaving the receiver

After the construction of the STJ is finished, the software will be compared with measured data of the operation. Through this validation, models can be verified with real values and it can be checked if they have to be adjusted to achieve better results.

The created channel burner, which considers a complete combustion process, enables the calculation of the necessary mass flow of fuel which is needed for a certain required temperature. Furthermore the model calculates the resulting composition with certain species in molar fraction of the exhaust gas.

Fig. 4 shows the attached burner model in Simulink.

image175

Fig. 4: Validation of the burner model

To validate the burner model different static states were calculated and the results were compared to calculation results of another software called Cycle-Tempo, developed by the Delft University of Technology (TU Delft). This Software allows to model, design and calculate thermodynamic cycles and its components at different states. The results for a calculation with both models in MATLAB and Cycle-Tempo are shown in Table 1. They show that the model calculates the same values with slight

differences due to rounding errors. Other comparisons come to the same results though the model is valid for using it in the simulation.

Results

MATLAB

Model

Cycle-Tempo

Difference

(%)

Pressure (Pa)

1.01325e5

1.01325e5

0 %

Temperature (K)

948.15

948.15

0 %

Mass Flow (kg/s)

11.688

11.688

0 %

Composition:

Molar Fraction CO2 (Vol%)

2.24

2.24

0 %

Molar Fraction H2O (Vol%)

5.33

5.33

0 %

Molar Fraction O2 (Vol%)

15.81

15.82

0.06 %

Molar Fraction Ar (Vol%)

0.91

0.91

0 %

Molar Fraction N2 (Vol%)

75.70

75.71

0.01 %

Mass Flow Fuel (kg/s)

0.188

0.188

0.6 %

Table 1: Validation results for the burner

Добавить комментарий

Ваш e-mail не будет опубликован. Обязательные поля помечены *