20120140505012

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20120140505012

  1. 1. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 5, May (2014), pp. 102-106 © IAEME 102 EXPERIMENTAL STUDY OF A SOLAR AIR HEATER Durgesh Kunvar Yadav, Dr. Ajeet Kumar Rai, Vivek Sachan MED, SSET, SHIATS-DU Allahabad-211007 (U.P.) India ABSTRACT In the present work, a solar air heater is designed, fabricated and its performance is evaluated in the forced convection mode in the Allahabad climatic condition. Solar air heater is a simple device, which captures the solar energy. Production of hot air by using solar air heater is a renewable energy heating technology used to process heat generation or space heating. Aluminium Absorber plate of size 1.12 m2 is painted black to absorb maximum insolation. The performance of the system is evaluated for the different mass flow rates of 0.023, 0.031, 0.038 and 0.046 kg/s. A maximum instantaneous efficiency of 85% is obtained with the minimum mass flow rate of 0.023 kg/s. INTRODUCTION The solar air heater device intercepts solar radiation, converts this radiation to the heat in air and delivers the hot air for use. The main components of a solar air heater is an absorber plate, one or more channels for the flowing air, insulation for the bottom and lateral sides of the solar collector and one or more transparent covers. The use of a blower is optional for the air supply. Solar air heaters are devices that utilize solar radiation for a variety of purposes. This heated air can be used in several applications such as drying agricultural products, space heating and air conditioning, water heating, industrial process heating and spraying operations. The primary disadvantage of these systems is the low heat transfer coefficient compared to systems that use liquid as the working fluid. This is the result of low heat transfer coefficient between the absorber plate and the air. Low heat transfer coefficients lead to low thermal efficiency of solar air heaters. For many years researchers have studied the enhancement of heat transfer coefficients of solar air heaters. To increase the efficiency of such a system, various configurations and designs have been proposed [1,2]. Satcunanathan and Deonarine [3] have suggested that the heat loss can be reduced by using two pass solar air heater. Whillier [4] carried out experiments on the conventional air heater consists of an absorbing plate, a rear plate, insulation below the rear plate, transparent cover on exposed side, and the air flows between the absorbing plate and rear plate. INTERNATIONAL JOURNAL OF ADVANCED RESEARCH IN ENGINEERING AND TECHNOLOGY (IJARET) ISSN 0976 - 6480 (Print) ISSN 0976 - 6499 (Online) Volume 5, Issue 5, May (2014), pp. 102-106 © IAEME: www.iaeme.com/ijaret.asp Journal Impact Factor (2014): 7.8273 (Calculated by GISI) www.jifactor.com IJARET © I A E M E
  2. 2. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 5, May (2014), pp. 102-106 © IAEME 103 Ranjan et al. [5] refers to an air heater with flow above the absorber which consists of an absorber plate with a transparent cover at the top and insulation at the bottom. The cover and the plate provide the passage for the air. Solar radiation, after transmission through the cover, is absorbed by the absorber plate. Sodha and Bansalt [6] have studied an air heater with flow on both sides of the absorber assuming that equal flow occurs both above and below the absorber plate and the heat transfer coefficient between the absorber plate and the air stream is same on either side. Yousef and Adam [7] have investigated the effect of mass flow rate, flow channel depth and collector length on the system thermal performance and pressure drop through the collector with and without porous medium. The present work is undertaken with the objective to investigate the performance of a solar air heater with different mass flow rate of air. EXPERIMENTAL SETUP A Solar Air Heater was constructed to determine the efficiency of solar air heater in forced convection mode. A flat-plate collector (single pass) consists of a absorber plate of size 1.21m X0.92 m, made up of galvanized Iron and cover plate of transparent plastic sheet. Silica is used to hold the sheet in place. Air is used as a heat exchanger medium. Absorber plate is painted black to absorb maximum insolation. Insulation is placed below the absorber plate to reduce the heat loss from the system. Fig. 1 shows the photograph of the solar air heater. The experimental setup was located at Solar Energy Laboratory in the Mechanical Engineering department of SHIATS, Allahabad. The experiments were conducted in the month of May 2014. The experiments were carried between the hours of 08:30 and 17:00 every day. The system is insulated from its base and two sides to prevent heat losses through the surroundings. Air is supplied to the system with the help of a fan. The flow rate of the fan is controlled and manipulated by a fan regulator. Solar intensity is measured by solarimeter (SURYAMAPI). Wind velocity is measured by anemometer. The temperature at the different points of the system is measured by J- type thermocouples. Fig 1: Experimental Setup of a Solar Air Heater
  3. 3. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 5, May (2014), pp. Thermal Efficiency The thermal efficiency of the solar air heater ( Where m =mass flow of air in kg/s Cp= specific heat of air in kJ/kgK Tout-Tin= Temperature difference between outlet air temperature and inlet air temperature A = area of the heater which captures maximum insolation in m Ib = intensity of solar radiation in W/m RESULTS AND DISCUSSION System was fabricated and experimentation were done for the different mass flow rate of air. Solar intensity was measured by solarimeter for four consecutive days in a month and variations a shown in fig 2 for different mass flow rate of air. Since solar intensity was almost same for all days, inlet temperatures are also equal which is shown in fig Fig 2: variation of solar intensity with time of the day at different mass flow ra Fig 3: shows that the variation of inlet temperature with time of the day at different mass flow rate International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 6499(Online) Volume 5, Issue 5, May (2014), pp. 102-106 © IAEME 104 The thermal efficiency of the solar air heater (η) is given by the following expression = specific heat of air in kJ/kgK = Temperature difference between outlet air temperature and inlet air temperature A = area of the heater which captures maximum insolation in m2 . = intensity of solar radiation in W/m2 . System was fabricated and experimentation were done for the different mass flow rate of air. Solar intensity was measured by solarimeter for four consecutive days in a month and variations a for different mass flow rate of air. Since solar intensity was almost same for all days, inlet temperatures are also equal which is shown in fig 3. variation of solar intensity with time of the day at different mass flow ra shows that the variation of inlet temperature with time of the day at different mass flow rate International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – © IAEME ) is given by the following expression: = Temperature difference between outlet air temperature and inlet air temperature System was fabricated and experimentation were done for the different mass flow rate of air. Solar intensity was measured by solarimeter for four consecutive days in a month and variations are for different mass flow rate of air. Since solar intensity was almost same for all days, variation of solar intensity with time of the day at different mass flow rate shows that the variation of inlet temperature with time of the day at different mass flow rate
  4. 4. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 5, May (2014), pp. Fig 4: Variation of outlet temperature with time of the day at different mass flow rate Fig. 4 shows variation of outlet temperature with time It is observed that outlet temperature is higher with lower mass flow rate of 0.023 kg/s. A maximum temperature gain of 28% is observed with a lower mass flow rate of 0.023 kg/s whereas 27% gain is observed with highest mass flow rate of 0.046 kg/s. Fig. difference between inlet and outlet is dominant for lower mass flow rate maximum time throughout the day. Fig 5: Variation of temperature difference between outlet temperature an time of the day at different mass flow rate CONCLUSION The fabricated solar air heater is very simple and easy to fabricate with locally available low cost materials. The air temperature obtained from the system was noteworthy. The instantaneous temperature of the air coming out from the system was 67 rate of 0.023 kg/s. The average daily efficiency of 45% is observed at this mass flow rate. The average daily efficiency of 55% is calculated at higher temperature difference of 12 degree is obtained in both the cases. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 6499(Online) Volume 5, Issue 5, May (2014), pp. 102-106 © IAEME 105 Variation of outlet temperature with time of the day at different mass flow rate of outlet temperature with time of the day at different mass flow rate. It is observed that outlet temperature is higher with lower mass flow rate of 0.023 kg/s. A maximum temperature gain of 28% is observed with a lower mass flow rate of 0.023 kg/s whereas 27% gain is hest mass flow rate of 0.046 kg/s. Fig.5 shows that variation of temperature difference between inlet and outlet is dominant for lower mass flow rate maximum time throughout Variation of temperature difference between outlet temperature and inlet temperature with time of the day at different mass flow rate The fabricated solar air heater is very simple and easy to fabricate with locally available low cost materials. The air temperature obtained from the system was noteworthy. The instantaneous temperature of the air coming out from the system was 670 C at a minimum mass flow rate of 0.023 kg/s. The average daily efficiency of 45% is observed at this mass flow rate. The average daily efficiency of 55% is calculated at higher mass flow rate of 0.046 kg/s. whereas average temperature difference of 12 degree is obtained in both the cases. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – © IAEME Variation of outlet temperature with time of the day at different mass flow rate of the day at different mass flow rate. It is observed that outlet temperature is higher with lower mass flow rate of 0.023 kg/s. A maximum temperature gain of 28% is observed with a lower mass flow rate of 0.023 kg/s whereas 27% gain is shows that variation of temperature difference between inlet and outlet is dominant for lower mass flow rate maximum time throughout d inlet temperature with The fabricated solar air heater is very simple and easy to fabricate with locally available low- cost materials. The air temperature obtained from the system was noteworthy. The maximum C at a minimum mass flow rate of 0.023 kg/s. The average daily efficiency of 45% is observed at this mass flow rate. The mass flow rate of 0.046 kg/s. whereas average
  5. 5. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 5, May (2014), pp. 102-106 © IAEME 106 REFERENCES 1. Kalogirou SA.(2004) Solar thermal collectors and applications. Prog Energy Combust Sci vol.30, pp.231–95. 2. Duffie JA, Beckman WA.(1991) Solar engineering of thermal processes. New York, USA: Wiley; 3. Satcunanathan S, Deonarine S.(1973) “A two-pass solar air heater. Solar Energy”. Vol. 15, pp. 41–9. 4. Whillier A. (1964) “Performance of black-painted solar air heaters of conventional design.” Solar Energy. Vol.8, pp. 31–7. 5. Ranjan V, Dhiman NK, Tiwari GN. (1983) “Performance of suspended flat plate air heater”. Energy Convers Management. Vol. 23 pp. 211–5. 6. Sodha MS, Bansalt NK.(1982) “Analysis of a non-porous double-flow solar air heater.” Applied Energy. Vol.12 pp. 251–8 7. Yousef BAA, Adam NM.(2008) “Performance analysis for flat plate collector with and without porous media. J Energy S Afr , vol 19 pp.32–42. 8. Ajeet Kumar Rai, Pratap Singh, Vivek Sachan and Nripendra Bhaskar, “Design, Fabrication and Testing of a Modified Single Slope Solar Still”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 4, Issue 4, 2013, pp. 8 - 14, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359. 9. Ajeet Kumar Rai, Ashish Kumar and Vinod Kumar Verma, “Effect of Water Depth and Still Orientation on Productivity of Passive Solar Still”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012, pp. 740 - 753, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359. 10. Ajeet Kumar Rai, Vivek Sachan and Maheep Kumar, “Experimental Investigation of a Double Slope Solar Still with a Latent Heat Storage Medium”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 4, Issue 1, 2013, pp. 22 - 29, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359. 11. Ajeet Kumar Rai, Nirish Singh and Vivek Sachan, “Experimental Study of a Single Basin Solar Still with Water Cooling of the Glass Cover”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 4, Issue 6, 2013, pp. 1 - 7, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359. 12. Ajeet Kumar Rai, Vivek Sachan and Bhawani Nandan, “Experimental Study of Evaporation in a Tubular Solar Still”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 4, Issue 2, 2013, pp. 1 - 9, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359. 13. Ihsan Mohammed Khudhur and Dr. Ajeet Kumar Rai, “Experimental Study of a Tubular Solar Still Integrated with a Fan”, International Journal of Advanced Research in Engineering & Technology (IJARET), Volume 5, Issue 3, 2014, pp. 1 - 8, ISSN Print: 0976-6480, ISSN Online: 0976-6499. 14. Hasan Falih M., Dr. Ajeet Kumar Rai, Vivek Sachan and Omar Mohammed I., “Experimental Study of Double Slope Solar Still with Energy Storage Medium”, International Journal of Advanced Research in Engineering & Technology (IJARET), Volume 5, Issue 3, 2014, pp. 147 - 154, ISSN Print: 0976-6480, ISSN Online: 0976-6499. 15. Ajay Kumar Kapardar and Dr. R. P. Sharma, “Experimental Investigation of Solar Air Heater using Porous Medium”, International Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012, pp. 387 - 396, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.

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