Thermal Analysis and Exergy of Linear Fresnel Reflectors for Feasibility of Use in Greenhouse Heating System

ماشین های کشاورزی

Article 4, Volume 13, Issue 2 - Serial Number 28, June 2023, Pages 147-162   

Document Type: Research Article

DOI: 10.22067/jam.2021.72345.1060

Authors

S. Noroozi¹; A. Maleki^{* 2}; Sh. Besharati²

¹M.Sc. Student of Mechanical Engineering of Biosystems Department, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran

²Mechanical Engineering of Biosystems Department, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran

Abstract

Introduction
Solar energy is one of the most important sources of renewable energy, and it is used to address problems related to energy needs, including increasing fossil fuels, rising energy transportation costs, higher energy demand worldwide, and greenhouse gas emissions. Solar collectors harness the sun's thermal energy to convert it into useful and usable energy. Solar collectors are divided into several types, including parabolic trough collectors (PTCs), linear Fresnel reflectors (LFRs), solar plates, and central towers. Among these, the most common heat generation systems are linear adsorption technologies. In this study, we examine the use of LFR technology for greenhouse heating during the winter in Shahrekord.
Materials and Methods
Previous studies (Huang et al., 2014) were used for optical analysis. The Daneshyar model was utilized to calculate the amount of solar energy available at a particular location. Mathematical formulas were employed to calculate the instantaneous energy equilibrium, and a heat transfer resistance model was developed to calculate the heat loss of different parts of the collector. To create a model, the total amount of exergy must first be calculated, which can be done by using the Petlla formula given by Bellos et al. (2019).
Results and Discussion
The following results were obtained from this study:

The proposed mathematical model for calculating solar energy was accurate in terms of daily and instantaneous performance. This model was valid for both clear and cloudy days, making it applicable in a variety of weather conditions.
The maximum useful heat production of the current system for February was about 2.5 kW, resulting in an increased liquid temperature of 16 degrees Celsius in the heat tank.
The maximum thermal efficiency of the Fresnel collector during the day was 64%, while the average daily efficiency was 56.4%.
The most significant parameters that affected the production of useful energy were the position of the sun during the day and the number of cloudy days.
The system was capable of heating stored water to 98 degrees per day, available for up to 14 hours.
The system under consideration can be used to produce heat up to 1260 watts for 15 hours without heating the tank. The generated heat can be utilized in the food industry for steam production and industrial desalination of water.
The decrease in exergy efficiency was due to the reduction in the thermal efficiency of the system and the increase in the thermal difference between the collector and ambient temperatures. Higher values can be achieved by reducing the heat losses, which is a reason to reduce the exergy efficiency of the system.

Conclusion
This paper investigated the daily performance of a linear Fresnel collector with an 18 square meter mirror field, a parabolic collector, and an insulated storage tank with a volume of 250 liters. The investigation included experimental analysis and theoretical formulation of thermal phenomena under the weather conditions of Shahrekord. The mathematical model developed for this system is based on the energy balance in the collector and storage tank. The results show that this is an efficient greenhouse heating system, with an average thermal efficiency of 56%, which is reasonable and competitive with other similar technologies. Additionally, the cost of construction and maintenance of this system is much lower than that of competitors.

Keywords

Concentrated collectors; Heat loss; Reflector; Thermal efficiency

References

1. Anifantis, A. S., Colantoni, A., & Pascuzzi, S. (2016). Thermal energy assessment of a small scale photovoltaic, hydrogen and geothermal stand-alone system for greenhouse heating. Renewable Energy, 103, 115-127. https://doi.org/10.1016/j.renene.2016.11.031
2. Attar, I., & Farhat, A. (2015). Efficiency evaluation of a solar water heating system applied to the greenhouse climate. Solar Energy, 119, 212-224. https://doi.org/10.1016/j.solener.2015.06.040
3. Babu, M., Raj, S. S., & Arasu, A. V. (2019). Experimental analysis on Linear Fresnel reflector solar concentrating hot water system with varying width reflectors. Case Studies in Thermal Engineering, 14, 100444. https://doi.org/10.1016/j.csite.2019.100444
4. Balaji, S., Reddy, K. S., & Sundararajan, T. (2016). Optical modelling and performance analysis of a solar LFR receiver system with parabolic and involute secondary reflectors. Applied Energy, 179, 1138-1151. https://doi.org/10.1016/j.apenergy.2016.07.082
5. Barbón, A., Barbón, N., Bayón, L., & Otero, J. A. (2016). Theoretical elements for the design of a small scale Linear Fresnel Reflector: Frontal and lateral views. Solar Energy, 132, 188-202. https://doi.org/10.1016/j.solener.2016.02.054
6. Barbón, A., Fernández-Rubiera, J. A., Martínez-Valledor, L., Pérez-Fernández, A., & Bayón, L. (2021). Design and construction of a solar tracking system for small-scale linear Fresnel reflector with three movements. Applied Energy, 285, 116477. https://doi.org/10.1016/j.apenergy.2021.116477
7. Baudoin, W., Nono-Womdim, R., Lutaladio, N., Hodder, A., Castilla, N., Leonardi, C., De Pascale, S., Qaryouti, M., & Duffy, R. (2013). Good agricultural practices for greenhouse vegetable crops: Principles for mediterranean climate areas. FAO plant production and protection paper (FAO).(book)
8. Bellos, E. (2019). Progress in the design and the applications of linear Fresnel reflectors–A critical review. Thermal Science and Engineering Progress, 10, 112-137. https://doi.org/10.1016/j.tsep.2019.01.014
9. Bellos, E., Mathioulakis, E., Papanicolaou, E., & Belessiotis, V. (2018). Experimental investigation of the daily performance of an integrated linear Fresnel reflector system. Solar Energy, 167, 220-230. https://doi.org/10.1016/j.solener.2018.04.019
10. Bellos, E., Mathioulakis, E., Tzivanidis, C., Belessiotis, V., & Antonopoulos, K. A. (2016). Experimental and numerical investigation of a linear Fresnel solar collector with flat plate receiver. Energy Conversion and Management, 130, 44-59. https://doi.org/10.1016/j.enconman.2016.10.041
11. Bellos, E., Tzivanidis, C., Korres, D., & Antonopoulos, K. A. (2015). Thermal analysis of a flat plate collector with Solidworks and determination of convection heat coefficient between water and absorber. In ECOS conference. https://doi.org/10.1177/0957650917712403
12. Belessiotis, V., Mathioulakis, E., & Papanicolaou, E. (2010). Theoretical formulation and experimental validation of the input–output modeling approach for large solar thermal systems. Solar Energy, 84(2), 245-255. https://doi.org/10.1016/j.solener.2009.10.024
13. Benyakhlef, S., Al Mers, A., Merroun, O., Bouatem, A., Boutammachte, N., El Alj, S., Ajdad, H., Erregueragui, Z., & Zemmouri, E. (2016). Impact of heliostat curvature on optical performance of Linear Fresnel solar concentrators. Renewable Energy, 89, 463-474. https://doi.org/10.1016/j.renene.2015.12.018
14. Boito, P., & Grena, R. (2021). Application of a fixed-receiver Linear Fresnel Reflector in concentrating photovoltaics. Solar Energy, 215, 198-205. https://doi.org/10.1016/j.solener.2020.12.024
15. Duffie, J. A., Beckman, W. A., & Blair, N. (2020). Solar engineering of thermal processes, photovoltaics and wind. John Wiley & Sons; 2020 Mar 24.(book)
16. Ebrahimpour, A., Maaref, M., & Nairi, H. (2009). Comparison of two different methods for estimating air purity coefficient for Iranian cities. Geography and Planning, 14(28), 1-16. (In Persian).
17. Forristall, R. (2003). Heat transfer analysis and modeling of a parabolic trough solar receiver implemented in engineering equation solver (No. NREL/TP-550-34169). National Renewable Energy Lab., Golden, CO.(US).
18. Hasandokht, M. (2005). Greenhouse management (greenhouse product technologies). Marze danesh publication, pp: 31-35. (In Persian).
19. Huang, F., Li, L., & Huang, W. (2014). Optical performance of an azimuth tracking linear Fresnel solar concentrator. Solar Energy, 108, 1-12. https://doi.org/10.1016/j.solener.2014.05.010
20. Jafari, M., Mortezapour, H., Jafari Naeimi, K., & Maharlooei, M. (2017). Performance Investigation of a Solar Greenhouse Heating System Equipped with a Parabolic Trough Solar Concentrator and a Double-Purpose Heat Journal of Agricultural Machinery, 7(2), 364-378. (In Persian with English abstract). https://doi.org/10.22067/jam.v7i2.56939
21. Jafarpour, Kh., & Karshenas, M. (2001). Cloud coefficient and its application in estimating solar radiation in different climates of Iran. Iranian Journal of Energy, 6 (1), 45-56. (In Persian).
22. Kalogirou, S. A. (2012). A detailed thermal model of a parabolic trough collector receiver. Energy, 48(1), 298-306. https://doi.org/10.1016/j.energy.2012.06.023
23. Loni, R., Kasaeian, A. B., Asli-Ardeh, E. A., & Ghobadian, B. (2016). Optimizing the efficiency of a solar receiver with tubular cylindrical cavity for a solar-powered organic Rankine cycle. Energy, 112, 1259-1272. https://doi.org/10.1016/j.energy.2016.06.109
24. Jovanović, M., Kašćelan, L., Despotović, A., & Kašćelan, V. (2015). The impact of agro-economic factors on GHG emissions: Evidence from European developing and advanced economies. Sustainability, 7(12), 16290-16310. https://doi.org/10.3390/su71215815
25. Ma, J., & Chang, Z. (2018). February. Understanding the effects of end-loss on linear Fresnelcollectors. In IOP Conference Series: Earth and Environmental Science (Vol. 121, No. 5, p. 052052). IOP Publishing. https://doi.org/10.1088/1755-1315/121/5/052052
26. Mokhtar, G., Boussad, B., & Noureddine, S. (2016). A linear Fresnel reflector as a solar system for heating water: theoretical and experimental study. Case Studies in Thermal Engineering, 8, 176-186. https://doi.org/10.1016/j.csite.2016.06.006
27. Nixon, J. D., Dey, P. K., & Davies, P. A. (2013). Design of a novel solar thermal collector using a multi-criteria decision-making methodology. Journal of Cleaner Production, 59, 150-159. https://doi.org/10.1016/j.jclepro.2013.06.027
28. Ozgener, O., & Hepbasli, A. (2006). An economical analysis on a solar greenhouse integrated solar assisted geothermal heat pump system. Journal of Energy Resources Technology, 128, 28-34. https://doi.org/10.1115/1.2126984
29. Petela, R. (2003). Exergy of undiluted thermal radiation. Solar Energy, 74(6), 469-488. https://doi.org/10.1016/S0038-092X(03)00226-3
30. Qiu, Y., He, Y. L., Cheng, Z. D., & Wang, K. (2015). Study on optical and thermal performance of a linear Fresnel solar reflector using molten salt as HTF with MCRT and FVM methods. Applied Energy, 146, 162-173. https://doi.org/10.1016/j.apenergy.2015.01.135
31. Said, Z., Ghodbane, M., Sundar, L. S., Tiwari, A. K., Sheikholeslami, M., & Boumeddane, B. (2021). Heat transfer, entropy generation, economic and environmental analyses of linear Fresnel reflector using novel rGO-Co3O4 hybrid nanofluids. Renewable Energy, 165, 420-437. https://doi.org/10.1016/j.renene.2020.11.054
32. Smith, P., Clark, H., Dong, H., Elsiddig, E. A., Haberl, H., Harper, R., House, J., Jafari, M., Masera, O., Mbow, C., & Ravindranath, N. H. (2014). Agriculture, forestry and other land use (AFOLU).
33. Smith, P., Martino, D., Cai, Z., Gwary, D., Janzen, H., Kumar, P., McCarl, B., Ogle, S., O'Mara, F., Rice, C., & Scholes, B. (2008). Greenhouse gas mitigation in agriculture. Philosophical transactions of the royal Society B: Biological Sciences, 363(1492), 789-813. https://doi.org/10.1098/rstb.2007.2184
34. Sharma, V., Nayak, J. K., & Kedare, S. B. (2015). Effects of shading and blocking in linear Fresnel reflector field. Solar Energy, 113, 114-138. https://doi.org/10.1016/j.solener.2014.12.026
35. Sherafati, K. (2009). Investigation of energy consumption indices of cucumber production in Tehran greenhouses. Final report of the research project of the Institute of Agricultural Technical and Engineering Research. (In Persian).
36. Tagle, P. D., Agraz, A., & Rivera, C. I. (2016). Study of applications of parabolic trough solar collector technology in Mexican industry. Energy Procedia, 91, 661-667. https://doi.org/10.1016/j.egypro.2016.06.227
37. Tzivanidis, C., & Bellos, E. (2016). The use of parabolic trough collectors for solar cooling–A case study for Athens climate. Case Studies in Thermal Engineering, 8, 403-413. https://doi.org/10.1016/j.csite.2016.10.003
38. Wang, G., Wang, F., Shen, F., Jiang, T., Chen, Z., & Hu, P. (2020). Experimental and optical performances of a solar CPV device using a linear Fresnel reflector concentrator. Renewable Energy, 146, 2351-2361. https://doi.org/10.1016/j.renene.2019.08.090
39. Xu, C., Chen, Z., Li, M., Zhang, P., Ji, X., Luo, X., & Liu, J. (2014). Research on the compensation of the end loss effect for parabolic trough solar collectors. Applied Energy, 115, 128-139. https://doi.org/10.1016/j.apenergy.2013.11.003