HEAT LOSS SENSITIVITY ANALYSIS OF DIFFERENT LINEAR FRESNEL COLLECTOR RECEIVER GEOMETRIES

Transcription

1 HEAT LOSS SENSITIVITY ANALYSIS OF DIFFERENT LINEAR FRESNEL COLLECTOR RECEIVER GEOMETRIES Master Thesis Presentation Tareq Yahia Zahw University of Kassel Cairo University Supervised by: Dr. Adel Khalil 18 June 2014

2 AGENDA Introduction Motivation Thermal Resistance Model Methodology & Results Conclusion Future Work 2

3 AGENDA Introduction Motivation Thermal Resistance Model Methodology & Results Conclusion Future Work 3

4 Introduction Potential for lower manufacturing and installation costs Less land area required for a given amount of produced electricity Lower leakage losses because of the fixed receiver 4

5 AGENDA Introduction Motivation Thermal Resistance Model Methodology & Results Conclusion Future Work 5

6 Motivation 6

7 Motivation Presence of the secondary receiver Absorbed radiation at the secondary receiver Thermal analysis: Efficiency = Useful Power Output Available Power Useful Output = Available Power Heat Loss Heat Loss Q = U ΔT +U ΔT + X = U T +U T + X 7

8 AGENDA Introduction Motivation Thermal Resistance Model Methodology & Results Conclusion Future Work 8

9 Thermal Resistance Model 9

10 Thermal Resistance Model 10

11 Thermal Resistance Model Glass envelope configuration Glass plate configuration 11

12 Thermal Resistance Model Non-evacuated glass envelope Evacuated glass envelope Glass plate 12

13 AGENDA Introduction Motivation Thermal Resistance Model Methodology & Results Conclusion Future Work 13

14 Sensitivity Analysis Methodology Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors 14

15 Sensitivity Analysis Methodology Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors 15

16 Methodology & Results Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors Geometry Material Ambient Process 16

17 Sensitivity Analysis Methodology Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors Why variance? Model-independent sensitivity measure. Appreciation of interaction effects among input factors. 17

18 Sensitivity Analysis Methodology Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors Main Index (S i ) The contribution of each input parameter to the output Total Index (S Ti ) Sum of both single and interaction effects 18

19 Methodology & Results Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors Geometry Material Ambient Process 19

20 Methodology & Results Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors Geometry Material Ambient Process 20

21 Ambient Parameters Non-evacuated glass envelope Wind velocity Incidence angle DNI Wind direction Ambient temperature Main index Total index 21

22 Ambient Parameters 22

23 Ambient Parameters Evacuated glass envelope Wind velocity Incidence angle DNI Wind direction Ambient temperature Main index Total index 23

24 Ambient Parameters 24

25 Ambient Parameters Wind velocity Incidence angle Glass plate DNI Wind direction Ambient temperature Main index Total index 25

26 Heat Losses (W/m) Ambient Parameters q_solabs (W/m) 400

27 Methodology & Results Thermal Resistance Model Sensitivity analysis Individual parameter study Global parameter study Variance-based method Sensitivity indices Parameter categories Response surface methodology R-squared value (coefficient of determination) Equation of coded factors 27

28 Methodology Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R 2 value (coefficient of determination) Equation of coded factors 28

29 Methodology Individual parameter study Global parameter study Parameter categories Variance-based method Sensitivity indices Response surface methodology R value (coefficient of determination) Equation of coded factors 29

30 Response Surface 2 Q loss = A o + A 1 v w + A 2 v w T abs T ambient + A 3 T abs T ambient + A 4 T abs Non-evacuated glass envelope 30

31 Response Surface 2 Q loss = A o + A 1 v w + A 2 v w T abs T ambient + A 3 T abs T ambient + A 4 T abs Evacuated glass envelope 31

32 Response Surface 2 Q loss = A o + A 1 v w + A 2 DNI + A 3 T abs T ambient + A 4 T abs Glass plate 32

33 AGENDA Introduction Motivation Methodology & Results Conclusion Future Work 33

34 Conclusion Glass envelope correlation: Q = A + v (A + A T T ) + A T T + A T R = 99.72% Glass plate correlation: Q = A + A v + A DNI + A T T + A T R = 99.65% Model validation Aperture area of the main mirrors Heat Fluid Temperature Reflectance of the secondary receiver 34

35 AGENDA Introduction Motivation Methodology & Results Conclusion Future Work 35

36 Future Work Validating the model with varying the geometry and material parameters Examining the LFC performance versus the proposed model Further studies for the dynamic evaluation of the heat loss 36

37 Thanks! Tareq Yahia Zahw 37