GÜNEŞ HAVUZLARINDA ISI ÇEKME ORANININ BELİRLENMESİ

Öz

Bu çalışmada, bir güneş havuzunda ısı çekme oranı, doğrudan çözücü PARDISO ile Ayrık Ordinatlar Yöntemi kullanılarak iç içe parçalara ayrılıp çok iş parçacıklı ön düzenleme algoritması ile sayısal olarak araştırılmış ve sayısal yaklaşımların simülasyon doğruluğu için eşanjörsüz güneş havuzunda yapılan ön nümerik sonuçlar deneysel verilerle Akdeniz iklim koşullarında karşılaştırılmıştır. Daha sonra, güneş havuzu önceki bir deney sistemi ile aynı boyutta modellenmiş ve ısı depolama bölgesine bir ısı eşanjörü yerleştirilmiş ve COMSOL ticari yazılımı ile sıcak suyun belirli bir akışta dışarı alınması için simülasyon gerçekleştirilmiştir. Adana için güneş konumu tanımlanmış ve ASHRAE Weather Data Viewer 5.0 ile işlenerek ortam verileri elde edilmiştir. Sonuç olarak, 0.007 kg/s debi için maksimum ve minimum ısı çekme oranı Temmuz ayında % 13.39 ve Eylül ayında % 2.96 olarak hesaplanmıştır; 0.014 kg/s debi için sırasıyla Haziran'da %24.27 ve Eylül'de %3.23'tür.

Anahtar Kelimeler

• Güneş enerjisi
• güneş havuzu
• ısıl enerji
• ısı transferi
• ısı eşanjörü

THE DETERMINATION OF THE HEAT EXTRACTION RATIO IN THE SOLAR POND

Öz

In this study heat extraction ratio of a solar pond was investigated numerically by using the Discrete Ordinates Method (DOM) with the direct solver PARDISO by using nested dissection multithreaded preordering algorithm, and the findings without exchanger were compared with experimental data to validate simulation accuracy of numerical approaches in the Mediterranean climatic condition. The solar pond was modeled with the same dimension as a previous experimental system and a heat exchanger was placed in the heat storage zone and simulation to take out the hot water at a certain flow was performed with the commercial software COMSOL. The solar position was defined for Adana and ambient data was obtained by processing the ASHRAE Weather Data Viewer 5.0. As a result, the maximum and minimum heat extraction ratio (HER) is calculated as 13.39 % in July and 2.96 % in September for a flow rate of 0.007 kg/s; 24.27 % in June, and 3.23 % in September for a flow rate of 0.014 kg/s, respectively.

Anahtar Kelimeler

• Solar energy
• solar pond
• thermal energy
• heat transfer
• heat exchanger

Kaynakça

1. Adana Meteorology Regional Office, 2018, Turkish State Meteorological Service, Ankara, Turkey.
2. Alcaraz A., Valderrama C., Cortina J.L., Akbarzadeh A. and Farran A., 2016, Enhancing the efficiency of solar pond heat extraction by using both lateral and bottom heat exchangers, Solar Energy, 134, 82-94.
3. Alcaraz A., Montalà M., Valderrama C., Cortina J.L., Akbarzadeh A. and Farran A., 2018, Increasing the storage capacity of a solar pond by using solar thermal collectors: Heat extraction and heat supply processes using in-pond heat exchangers, Solar Energy, 17, 112-121.
4. Amirifard M., Kasaeian A. and Amidpour M., 2018, Integration of a solar pond with a latent heat storage system, Renewable Energy, 125, 682-693.
5. Aramesh M., Pourfayaz F. and Kasaeian A., 2017, Numerical investigation of the nanofluid effects on the heat extraction process of solar ponds in the transient step, Solar Energy, 157, 869–879.
6. Assari M.R., Tabrizi H.B. and Beik A.J.G., 2015, Experimental studies on the effect of using phase change material in salinity-gradient solar pond, Solar Energy, 122, 204–214.
7. Bozkurt I. and Karakilcik M., 2012, The daily performance of a solar pond integrated with solar collectors, Solar Energy, 86, 1611–1620.
8. Bozkurt I., Atiz A., Karakilcik M. and Dincer I., 2014, An investigation of the effect of transparent covers on the performance of cylindrical solar ponds, International Journal of Green Energy, 11, 404–416.

9. Bozkurt I. and Karakilcik M., 2015, The effect of sunny area ratios on the thermal performance of solar ponds, Energy Conversion and Management, 91, 323–332.
10. Bryant H.C. and Colbeck I., 1977, A solar pond for London, Solar Energy, 19, 321-322.
11. COMSOL, 2018, Heat Transfer Module, https://www.comsol.com [accessed 30 December 2020]
12. Date A., Yaakob Y., Date A., Krishnapillai S. and Akbarzadeh A., 2013, Heat extraction from Non-Convective and Lower Convective Zones of the solar pond: A transient study, Solar Energy, 97, 517–528.
13. El-Sebaii A.A., Aboul-Enein S., Ramadan M.R.I. and Khallaf A.M., 2013, Thermal performance of shallow solar pond under open and closed cycle modes of heat extraction, Solar Energy, 95, 30–41.
14. Karakilcik M., Bozkurt I. and Dincer I., 2013a, Dynamic exergetic performance assessment of an integrated solar pond, Int. J. Exergy, 12, 70–86.
15. Karakilcik M., Dincer I., Bozkurt I. and Atiz A., 2013b, Performance assessment of a solar pond with and without shading effect, Energy Conversion and Management, 65, 98–107.
16. Karakilcik M., Dincer I. and Rosen M.A., 2006, Performance investigation of a solar pond, Applied Thermal Engineering, 26, 727–735.
17. Khalilian M., Pourmokhtar H. and Roshan A., 2018, Effect of heat extraction mode on the overall energy and exergy efficiencies of the solar ponds: A transient study, Energy, 154, 27-37.
18. Leblanc J., Akbarzadeh A., Andrews J., Lu H. and Golding P., 2011, Heat extraction methods from salinity-gradient solar ponds and introduction of a novel system of heat extraction for improved efficiency, Solar Energy, 85, 3103–3142.
19. Mansouri A.E., Hasnaoui M., Amahmid A. and Dahani Y., 2018, Transient theoretical model for the assessment of three heat exchanger designs in a large-scale salt gradient solar pond: Energy and exergy analysis, Energy Conversion and Management, 167, 45–62.
20. Modest M.F., 2013, Radiative Heat Transfer, 2nd ed., San Diego, California: Academic Press.
21. Renewables 2017 Global Status Report, 2018, http://www.ren21.net/gsr-2017/(accessed 19 September 2018).