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					               New Approach for Heat Loss
            Characterization from Solar Receiver
                                Technical Paper Presented
                                           at
                                            VNIT Nagpur
                                                   at
                              1 st India International Energy Summit



                                               by
                                         Milind S. Patil
                                     (Registration ID 262)


                                     Authored By
      Prof. Ajay Chandak                         Dr. Neeraj Agrawal
Department of Mechanical Engineering       Dr. Babasaheb Ambedkar Technological
S.S.V.P.S B.S.D College of Engineering            University Lonere, Raigad
                Dhule
                                                       Milind Patil
       Dr. Sunil Somani                    Dr. Babasaheb Ambedkar Technological
   Director MEDI CAPS Institute of                University Lonere, Raigad
         Technology Indore
Outline of Presentation
            Need

      Literature Review

      Problem Definition

  Experimental Methodology

         Test Method

Advantages of Such Methodology

         References




                                 21 Jan 2011 by MSP
                    Need
   Concentrators

   Receivers        for
    energy Conversions

   Heat    Loss    from
    Receiver

   Common Geometry




                           21 Jan 2011 by MSP
Literature Review




                    21 Jan 2011 by MSP
Different Geometries of
      the Receiver




                          21 Jan 2011 by MSP
           Status of Work Done on
               Similar Problem
     Researchers                 Receiver Used    Reported

  S. Paitoonsurikarn and K.                        Natural and
          Lovegrove                                 Combined
Centre of Sustainable Energy                     Convection Heat
          Systems,                                    Loss
 Department of Engineering,
Australian National University




  S. Paitoonsurikarn and K.                        Natural and
          Lovegrove                                 Combined
Centre of Sustainable Energy                     Convection Heat
          Systems,                                    Loss
 Department of Engineering,
Australian National University




                                                                   21 Jan 2011 by MSP
           Status of Work Done on
               Similar Problem
     Researchers                 Receiver Used      Reported

     Siangsukone P. and                          Modeling of a steam
        Lovegrove K.,                            based Paraboloidal
   Centre for Sustainable                         Dish concentrator
       Energy Systems
Australian National University
    Canberra, ACT 0200
         AUSTRALIA




  S. Paitoonsurikarn and K.                      Natural Convection
          Lovegrove                                  Heat Loss
Centre of Sustainable Energy
          Systems,
 Department of Engineering,
Australian National University




                                                                      21 Jan 2011 by MSP
           Status of Work Done on
               Similar Problem
     Researchers                 Receiver Used           Reported

  T. Taumoefolau and K.                               Natural Convection
        Lovegrove                                      Heat Loss from a
  Centre for Sustainable                                     Solar
     Energy Systems,                                  Concentrator Cavity
Department of Engineering,                            Receiver at Varying
    Australian National                                   Orientation
        University,
   Canberra ACT 0200,
       AUSTRALIA.



  S. Paitoonsurikarn and K.                           Natural Convection
          Lovegrove                                       Heat Loss
Centre of Sustainable Energy
          Systems,
 Department of Engineering,
Australian National University




                                 Macdonald Receiver

                                                                           21 Jan 2011 by MSP
Natural Convection Heat
          Loss




                          21 Jan 2011 by MSP
                               Summary of
                              Investigations
                                                                       Type of
                                           Opening       Opening
Sr.                      Aspect Ratio of                              Boundary
        References                         Ratio of    Displacement               φ   Pr        Ra or GrH
No.                         Cavity                                    Condition
                                            Cavity    Ratio of Cavity
                                                                          s
         Sernas and
01       Kyriakides            1              1            0.5           III      0   0.7        GrH = 107
           (1982)

       Chan and Tien
02                          1, 0.143          1            0.5           II       0   1,7     103 < RaB < 107
          (1985)

      Hess and Henze                                                                        3 x 1010 < RaB < 2 x
03                             1            0.5, 1         0.5           II       0   7
          (1984)                                                                                    1011

       Chan and Tien
04                           0.143            1            0.5           II       0   8.7     106 < RaB < 108
          (1986)

        H. Skok, S.
      Ramadhyani, and                                                                       3.5x106 < RaH < 1.2
05                             1.5           0.5           0.5            I       0   7
      R. J. Schoenhals                                                                             x109
            (1991)




                                                                                                         21 Jan 2011 by MSP
                                     Summary of
                                    Investigations
                                            Opening       Opening         Type of
Sr.                       Aspect Ratio of
        References                          Ratio of   Displacement      Boundary       φ      Pr         Ra or GrH
No.                          Cavity
                                             Cavity    Ratio of Cavity   Conditions

        Lin and Xin
06                              1              1             0.5             II         0      0.7      RaB = 1010 , 1011
          (1992)


       Angirasa et al.                                                                         0.1-
07                              1              1             0.5             II         0               102 < RaB < 108
          (1992)                                                                                1

         Mohamad
08                              1            0.5, 1          0.5             I        -45-80   0.7    7x103 < RaB < 7x104
          (1995)

      Polat and Bilgen
09                         0.125, 0.5, 1       1             0.5            IV        -45-0     1      103 < RaB < 1010
           (2002)
         Saha et al.
10                              1              1             0.5          II & IV     -60-0    0.71     103 < RaB < 106
          (2007)
      M.Nateghi et. al.
11                              1              1             0.5             III        0       1      105 < RaB < 1010
         (2004)
      H. Nouanegue, A.
12     Muftuoglu, E.        0.4, 0.7, 1        1             0.5             V          0      0.7     109 < RaB < 1012
       Bilgen (2008)




                                                                                                                        21/01/2001 by MSP
             Boundary Conditions

Type of Boundary
                       Wall – 1             Wall – 2             Wall – 3         Wall – 4
   Condition

       I                  Tw                   Tw                   Tw              Tw

       II                 Tw                    a                    a               a

       III                Tw                   Tw                   T∞              NA

                   Constant Heat Flux
                                                a                    a               a
                        on Wall
                                        Constant Heat Flux
      IV                   a                                         a               a
                                             on Wall
                                                             Constant Heat Flux
                           a                    a                                    a
                                                                  on Wall
                   Constant Heat Flux
       V                                        a                    a              NA
                        on Wall




                                                                                             21 Jan 2011 by MSP
               Problem Definition
   Tracking is the requirement hence position of the receiver
    changes continually

   Heat loss can be well simulated experimentally

   How ever heat losses are measured by thermal
    measurement and not by the electrical wattmeter.
    Electrical measurements are very accurate and precise as
    compared to thermal measurements. Therefore the aim of
    this study is to develop a method and apparatus that can
    simulate field condition of receiver in laboratory and data
    so generated can be easily correlated to the field
    situation.



                                                             21 Jan 2011 by MSP
Experimental Methodology




                           21 Jan 2011 by MSP
Experimental Methodology




                           21 Jan 2011 by MSP
Experimental Methodology




                           21 Jan 2011 by MSP
                    Test Method
                             Example

Let operating temperature is 125 degree C

Ambient temperature is 25 degree C

Wind velocity is 2 mtrs per second

Directed at 45 degree angle to the exposed face of the receiver.

In equilibrium condition, power consumption           recorded     by
electrical wattmeter is 1400 Whr in one hour.

Then loss rate for this operating condition is 1400 Watts.

Thus Heat loss value of 1400 watt at temperature difference of
100 degree C and wind velocity and direction as specified.



                                                                   21 Jan 2011 by MSP
                      Test Method
   Average solar beam radiation is say 800 watts

   Concentrator has area of 5 sqm

   Energy input is 4000 watts.

   Out of this say 3500 watts reaches the receiver after
    discounting for reflectivity of mirror and absorptivity of the
    receiver.

   In the first case when the losses are 1400 watts, means useful
    gain will be 3500 – 1400 = 2100 watts and efficiency will be
    2100/4000*100 = 52.5%.




                                                                21 Jan 2011 by MSP
           Advantages of Such Test
                  Method
   Heat losses are measured by electrical wattmeter and not by
    thermal measurement. Electrical measurements are very
    accurate and precise as compared to thermal measurements.
   With this methodology heat loss characterization can be
    established within laboratory. No need of Sun. Testing is
    possible even at night.
   As incoming solar radiation varies with time and location hence
    performance of the solar concentrator 101 and receiver 103
    system will vary. With this method of measurement, it is
    possible to predict heat losses from the solar receiver 103, in
    different operating conditions like operating temperature,
    ambient temperature, wind velocity, angle of wind approach etc.
   Same method can be used for comparing different designs of
    solar receivers 103 for heat loss characterization on one to one
    basis.


                                                                  21 Jan 2011 by MSP
           Advantages of Such Test
                  Method
   Same method of testing can be used for comparing different
    coatings on exposed face 107 of solar receiver 103.
   With simple calculation procedure, it is possible to predict
    performance of the solar concentrator-oven system at different
    operating parameters with great accuracy.
   If sensors are installed at any site for recording working
    temperature, ambient temperature, solar beam radiation, wind
    velocity and wind direction then it is possible to compare system
    performance with expected performance.
   Same method can also be used to study effect of different
    measures like wind protection funnel or other wind obstructions
    over the performance of the solar receivers 103.




                                                                   21 Jan 2011 by MSP
                           References
1. S. P. Sukhatme “Solar Energy”, TATA McGraw Hill Publication, Third Edition,
   ISBN (13): 978-0-07-026064-1, 71-107
2. Duffie, John A., and Beckman, William A., “Solar Engineering of Thermal
   Processes”, 2nd edition. Wiley, New York, 1991.
3. H. Skok, S. Ramadhyani, and R. J. Schoenhals, “International Journal of Heat
   and Fluid Flow, 12 (1991) 01, 36-45.
4. A. M. Clausing, “An Analysis of Convective Heat Looses from Cavity Solar
   Central Receivers” Solar Energy, 27 (1981), 4, 295-300
5. James A Harrist, Terry G Lenz, “Thermal Performance of Solar
   Concentrator/Cavity Receiver Sysem”, Solar Energy, 34 (1985), 2, 135-142.
6. Leibfried, U., Ortjohann, J., “Convective heat loss from upward and downward-
   facing cavity solar receivers: measurements and calculations”, ASME Journal
   of Solar Energy Engineering, 117, (1995), 75–84
7. H. Nouanegue, A. Muftuoglu, E. Bilgen, “Conjugate heat transfer by natural
   convection, conduction and radiation in open cavities” International Journal of
   Heat and Mass Transfer, 51 (2008), 6054-6062
8. Sernas, V., Kyriakides, I., 1982. Natural convection in an open cavity.
   In:Proceeding      of   7th     International    Heat    Transfer  Conference,
   Munchen,Germany, 2 (1982), 275–286.
9. Chan, Y.L., Tien, C.L., A numerical study of two-dimensional, laminar natural
   convection in a shallow open cavity. International Journal of Heat and Mass
   Transfer 28 (1985), 603–612.
                                                                          21 Jan 2011 by MSP
                              References
10.Chan, Y.L., Tien, C.L., A numerical study of two-dimensional, natural
   convection in square open cavities. Numerical Heat Transfer, Part B 8, (1985)
   65–80.
11. Lin, C.X., Xin, M.D., Transient turbulence free convection in an, open cavity.
   Institution of Chemical Engineers Symposium Series 1, (a1992) 515–521.
12. Angirasa, D., Pourquie, M.J., Nieuwstadt, F.T., Numerical study of transient
   and steady laminar buoyancy-driven flows and heat transfer in a square open
   cavity. Numerical Heat Transfer, Part A 22, (1992) 223–239.
13. Mohamad, A.A., Natural convection in open cavities and slots. Numerical Heat
   Transfer, Part A 27 (1995),705–716.
14. Polat, O., Bilgen, E., Laminar natural convection in inclined open shallow
   cavities. International Journal of Thermal Sciences 41 (2002), 360–368.
15. Saha, G., Saha, S., Arif Hasan Mamun, Md., A finite element method for
   steady-state natural convection in a square tilt open cavity. ARPN Journal of
   Engineering and Applied Sciences 2, (2007) 41–49.
16. Nateghi, M., Armfield, S.W., Natural convection flow of air in an inclined open
   cavity. Australian & New Zealand Industrial and Applied Mathematics Journal
   45, (2004) C870–C890.
17. Stine, W.B., McDonald, C.G., “Cavity Receiver convective heat loss”
   Proceedings of the International Solar Energy Society (ISES) Solar World
   Conference, 1989 Kobe, Japan.
18. Leibfried, U., Ortjohann, J., Convective heat loss from upward and downward-
   facing cavity solar receivers: measurements and calculations. ASME Journal of
   Solar Energy Engineering 117 (1995), 75–84.                               21 Jan 2011 by MSP
                           References
19.Siangsukone P. and Lovegrove K., “Modelling of a steam based Paraboloidal
   Dish concentrator using the computer source code TRNSYS” Proceedings of
   Solar 2002 - Australian and New Zealand Solar Energy Society Paper 1.
20. T. Taumoefolau and K. Lovegrove, “An Experimental Study of Natural
   Convection Heat Loss from a Solar Concentrator Cavity Receiver at Varying
   Orientation” Proceedings of Solar 2002 – Australian and New Zealand Solar
   Energy Society Paper 1
21. S. Paitoonsurikarn and K. Lovegrove, “A New Correlation for Predicting the
   Free Convection Loss from Solar Dish Concentrating Receivers” Clean Energy?
   – Can Do! – ANZSES 2006.
22. Paitoonsurikarn, S., Lovegrove, K., 2003. On the study of convection loss
   from open cavity receivers in solar paraboloidal dish applications. In:
   Proceedings of 41st Conference of the Australia and New Zealand Solar
   Energy Society (ANZSES), Melbourne, Australia.
23. N. Sendhil Kumar, K.S. Reddy, “Numerical investigation of natural convection
   heat loss in modified cavity receiver for fuzzy focal solar dish concentrator”,
   Solar Energy 81 (2007) 846–855
24. Prakash, M., Kedare, S.B., Nayak, J.K., Investigations on heat losses from a
   solar cavity receiver. Solar Energy 83 (2009), 157–170.
25. K.S. Reddy, N. Sendhil Kumar, “An Improved model for natural convection
   heat loss from modified cavity receiver of solar dish concentrator”, Solar
   Energy 83 (2009), 1884 – 1892.

                                                                          21 Jan 2011 by MSP
                          References
26.T Paitoonsurikarn, S., Taumoefolau, T., Lovegrove, K., 2004. Estimation of
   convection loss from paraboloidal dish cavity receivers. In: Proceedings of
   42nd Conference of the Australia and New Zealand Solar Energy Society
   (ANZSES), Perth, Australia.

27.M. Prakash, S.B. Kedare, J.K. Nayak, Investigations on heat losses from a
   solar cavity receiver, Solar Energy 83 (2009) 157–170

26.Ajay Chandak, Sunil k Somani, Deepak Dubey, “Journal of Engineering
   Science and Technology” 4 (2009), No 3, 315-321

26.Ajay Chandak, Sunil Somani, Vishal Sardeshpande: Apparatus for heat loss
   characterization of solar ovens: Indian Patent application no. 1607/MUM/2010




                                                                        21 Jan 2011 by MSP
Thanks



         21 Jan 2011 by MSP

				
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