ABSTRACT
Prospects for low-cost utilization and storage of solar energy are promising. In this study, the change of shallow geo-temperature was monitored, and the influence of solar radiation on shallow geo-temperature was discussed. Three series of field experiments on heat transfer of aboveground pipes were designed, and the variations of water temperature in the aboveground pipes were also monitored. According to the experimental data, the relevant factors affecting the water temperature inside the pipe (such as solar radiant intensity, pipe’s material, pipe’s spatial location, heat-accumulating wall and so on) were analyzed. Based on the field test, a 3-D model of aboveground pipe heat transfer was established to verify and temperature prediction was carried out. The results show that the water temperature in the pipe is most significantly affected by solar radiation, and is also related to the color of the pipe and its spatial position. The water temperature of galvanized steel pipe wrapped with black plastic film is the highest under solar radiation, and the op¬timum distance between the pipe and the heat-accumulating wall and the Earth’s surface is, respectively, 0.90~1.25 times of the outer diameter of the pipe. The way the pipe is covered has a great influence on the water temperature inside the pipe. When the black and polyethylene pipe covered with the white plastic film is in the best spatial position, the highest heat of the three series of tests is obtained, and the difference between the water temperature inside the pipe and the atmospheric temperature reaches 36.3°C.
KEYWORDS
PAPER SUBMITTED: 2019-07-27
PAPER REVISED: 2019-10-13
PAPER ACCEPTED: 2019-10-28
PUBLISHED ONLINE: 2019-11-17
THERMAL SCIENCE YEAR
2020, VOLUME
24, ISSUE
Issue 2, PAGES [1445 - 1460]
- Kumar, A., et al., Experimental Investigation of an Air Heating System Using Different Types of Heat Exchangers Incorporated with an Evacuated Tube Solar Collector, Environmental Progress & Sustainable Energy, 36(2017), 1, pp. 232-247.
- Huo, Z., et al., Research Report on Development of China Solar Thermal Industry, in: Annual Conference and Summit Forum of China Solar Energy Thermal Utilization Industry in 2011, China Solar Thermal Industry Federation, Xi'an, China, 2011.
- Liu, G., et al., Effect of Different Installation Tilt Angles on Electricity Yield in PV Power Station (in Chinese), Acta Energiae Solaris Sinica, 36 (2016), 12, pp. 2973-2978.
- Recalde, C., et al., Effect of Tilt Angle of Evacuated Tubes on the Temperature of the Water, Información Tecnológica, 26 (2015), 4, pp. 89-96.
- Tang, R., et al., Optimal Tilt-Angles of All-Glass Evacuated Tube Solar Collectors, Energy, 34 (2009), 9, pp. 1387-1395.
- Vall, S., et al., Energy Savings Potential of a Novel Radiative Cooling and Solar Thermal Collection Concept in Buildings for Various World Climates, Energy Technology,6 (2018), 11, pp. 2200-2209.
- Bracamonte, J., et al., Effect of The Collector Tilt Angle on Thermal Efficiency and Stratification of Passive Water in Glass Evacuated Tube Solar Water Heater, Applied Energy, 155 (2015), pp. 648-659.
- Huang, J. B., et al., Experimental Investigation on Thermal Performance of Thermosyphon Flat-Plate Solar Water Heater with a Mantle Heat Exchanger, Energy, 35 (2010), 9, pp. 3563-3568.
- Yakup, MABHM., Malik, A.Q., Optimal Tilt-Angle and Orientation for Solar Collectors in Brunei, Darussalam, Renewable Energy, 24 (2001), 2, pp. 223-234.
- Zhao, J., et al., Calculation and Analysis of The Optimum Angle of Solar Collectors in Lanzhou (in Chinese), Building Energy Efficiency, 47 (2019), 1, pp.28-31.
- Despotovic, M., Nedic, V., Comparison of Optimum Tilt Angles of Solar Collectors Determined at Yearly, Seasonal and Monthly Levels, Energy Conversion and Management, 97 (2015), pp. 121-131.
- A. Khan, M. M., et al., Evaluation of Solar Collector Designs with Integrated Latent Heat Thermal Energy Storage: A Review, Solar Energy,166 (2018), pp. 334-350.
- Lin, S. C., et al., Experiment Investigation on the Performance Enhancement of Integrated PCM-Flat Plate Solar Collector, Journal of Applied Sciences, 23 (2012), 12, pp. 2390-2396.
- Abuşka, M., et al., Experimental Analysis of Solar Air Collector with PCM-Honeycomb Combination Under the Natural Convection, Solar Energy Materials and Solar Cells, 195 (2019), pp. 299-308.
- Román-Roldán, N. I., et al., Computational Fluid Dynamics Analysis of Heat Transfer in a Greenhouse Solar Dryer "Chapel-Type" Coupled to an Air Solar Heating System, Energy Science & Engineering, 7 (2019), 4, pp. 1123-1139.
- Tanha, K., et al., Simulation and Experimental Investigation of Two Hybrid Solar Domestic Water Heaters with Drain Water Heat Recovery, Int. J. Energy Res, 39 (2015), 14, pp.1879-1889.
- Benoit, H., et al., Three‐Dimensional Numerical Simulation of up-Flow Bubbling Fluidized Bed in Opaque Tube Under High Flux Solar Heating, American Institute of Chemical Engineers, 64 (2018), 11, 3857-3867.
- Alfaro-Ayala, J. A., et al., Numerical Study of a Low Temperature Water-in-Glass Evacuated Tube Solar Collector, Energy Conversion and Management, 94 (2015), pp. 472-481.
- Morrison, G. L., et al., Water-in-Glass Evacuated Tube Solar Water Heaters, Solar Energy, 76 (2004), 1-3, pp. 135-140.
- Selmi, M., et al., Validation of CFD Simulation for Flat Plate Solar Energy Collector, Renewable Energy, 33 (2008), 3, pp.383-387.
- Charvat, P., et al., Solar Air Collector with the Solar Absorber Plate Containing a PCM Environmental Chamber Experiments and Computer Simulations, Renewable Energy, 143, (2019), pp.731-740.
- Ayompe, L. M., et al., Comparative Field Performance Study of Flat Plate and Heat Pipe Evacuated Tube Collectors (Etcs) for Domestic Water Heating Systems in a Temperate Climate, Energy, 36 (2011), 5, pp. 3370-3378.
- Tao, W., et al., Heat Transfer (in Chinese)(in Chinese), 4th edition, Higher Education Press, Beijing, China, 2006.
- Han, Z. Z., et al., FLUENT Fluid Engineering Emulator Calculation Example and Application (in (in Chinese)Chinese), Beijing Institute of Technology Press, Beijing, China, 2004.
- Kuharat, S., et al., Computational Study of Heat Transfer in Solar Collectors with Different Radiative Flux Models, Energy Technology, 48 (2019), pp. 1002-1031.
- Xiao, X., Experimental and Numerical Study on Temperature of Steel Members and Single-Layer Lattice Shell Considering Coupling of Radiation, Thermal and Fluid (in Chinese), Master dissertation, Tianjin University, China, 2014.
- Duan, X. S., et al., Multiple Linear Regression Analysis Method for in-Situ Thermal Conductivities of Rock and Soil Layer (in Chinese), Acta Energiae Solaris Sinica, 39 (2018), 2, pp. 385-389.