Modeling analysis on solar steam generator employed in multi-effect distillation (MED) system

Abstract

Recently the porous bilayer wood solar collectors have drawn increasing attention because of their potential application in solar desalination. In this paper, a thermodynamic model has been developed to analyze the performance of the wood solar collector. A modeling analysis has also been conducted to assess the performance and operating conditions of the multiple effect desalination (MED) system integrated with the porous wood solar collector. Specifically, the effects of operating parameters, such as the motive steam temperature, seawater flow rate, input solar energy and number of effects on the energy consumption for each ton of distilled water produced have been investigated in the MED desalination system combined with the bilayer wood solar steam generator. It is found that, under a given operating condition, there exists an optimum steam generation temperature of around 145°C in the wood solar collector, so that the specific power consumption in the MED system reaches a minimum value of 24.88 kWh/t. The average temperature difference is significantly affected by the solar heating capacity. With the solar capacity increasing from 50 kW to 230 kW, the average temperature difference increases from 1.88°C to 6.27°C. This parametric simulation study will help the design of efficient bilayer wood solar steam generator as well as the MED desalination system.

Keywords

solar energy / steam generating / multi-effect desalination

References

[1] Khawaji A D, Kutubkhanah I K, Wie J M. Advances in seawater desalination technologies. Desalination, 2008, 221(1–3): 47–69

[2] Ghaffour N, Missimer T M, Amy G L. Technical review and evaluation of the economics of water desalination: current and future challenges for better water supply sustainability. Desalination, 2013, 309: 197–207

[3] Elimelech M, Phillip W A. The future of seawater desalination: energy, technology, and the environment. Science, 2011, 333(6043): 712–717

[4] Cipollina A, Micale G, Rizzuti L. Seawater Desalination: Conventional and Renewable Energy Processes. Berlin: Springer, 2009

[5] Al-Karaghouli A, Kazmerski L L. Energy consumption and water production cost of conventional and renewable-energy-powered desalination processes. Renewable & Sustainable Energy Reviews, 2013, 24: 343–356

[6] Al-Nory M, El-Beltagy M. An energy management approach for renewable energy integration with power generation and water desalination. Renewable Energy, 2014, 72: 377–385

[7] Elminshawy N A S, Siddiqui F R, Sultan G I. Development of a desalination system driven by solar energy and low grade waste heat. Energy Conversion and Management, 2015, 103: 28–35

[8] Reddy K V, Ghaffour N. Overview of the cost of desalinated water and costing methodologies. Desalination, 2007, 205(1–3): 340–353

[9] Darwish M A, Al-Juwayhel F, Abdulraheim H K. Multi-effect boiling systems from an energy viewpoint. Desalination, 2006, 194(1–3): 22–39

[10] Zhang F M, Xu S M, Feng D D, Chen S Q, Du R X, Su C J, Shen B Y. A low-temperature multi-effect desalination system powered by the cooling water of a diesel engine. Desalination, 2017, 404: 112–120

[11] Zhang Y, Sivakumar M, Yang S Q, Enever K, Ramezanianpour M. Application of solar energy in water treatment processes: a review. Desalination, 2018, 428: 116–145

[12] Sun J, Liu Q B, Hong H. Numerical study of parabolic-trough direct steam generation loop in recirculation mode: characteristics, performance and general operation strategy. Energy Conversion and Management, 2015, 96: 287–302

[13] Li L, Sun J, Li Y S. Thermal load and bending analysis of heat collection element of direct-steam-generation parabolic-trough solar power plant. Applied Thermal Engineering, 2017, 127: 1530–1542

[14] Bataineh K M. Multi-effect desalination plant combined with thermal compressor driven by steam generated by solar energy. Desalination, 2016, 385: 39–52

[15] Sharaf M A, Nafey A S, García-Rodríguez L. Thermo-economic analysis of solar thermal power cycles assisted MED-VC (multi effect distillation-vapor compression) desalination processes. Energy, 2011, 36(5): 2753–2764

[16] El-Nashar A M. The economic feasibility of small MED seawater desalination plants for remote arid areas. Desalination, 2001, 134(1): 173–186

[17] Al-Mutaz I S, Wazeer I. Current status and future directions of MED-TVC desalination technology. Desalination and Water Treatment, 2014, 55(1):1–9

[18] Zhao D, Xue J, Li S, Sun H, Zhang Q D. Theoretical analyses of thermal and economical aspects of multi-effect distillation desalination dealing with high salinity waste water. Desalination, 2011, 273(2–3): 292–298

[19] ScienceDaily. Solar-powered devices made of wood could help mitigate water scarcity crisis. 2017–10–17, https://www.sciencedaily.com/releases/2017/10/171010224556.htm

[20] The Chemical Engineer. Wood improves solar steam generation. 2017–11–16, https://www.thechemicalengineer.com/news/wood-improves-solar-steam-generation/

[21] Zhu M, Li Y, Chen G, Jiang F, Yang Z, Luo X, Wang Y, Lacey S D, Dai J, Wang C, Jia C, Wan J, Yao Y, Gong A, Yang B, Yu Z, Das S, Hu L. Tree-inspired design for high-efficiency water extraction. Advanced Materials, 2017, 29(44): 1704107

[22] Chen C, Li Y, Song J, Yang Z, Kuang Y, Hitz E, Jia C, Gong A, Jiang F, Zhu J Y, Yang B, Xie J, Hu L. Highly flexible and efficient solar steam generation device. Advanced Materials, 2017, 29(30): 1701756

[23] Peng G, Ding H, Sharshir S W, Li X, Liu H, Ma D, Wu L, Zang J, Liu H, Yu W, Xie H, Yang N. Low-cost high-efficiency solar steam generator by combining thin film evaporation and heat localization: both experimental and theoretical study. Applied Thermal Engineering, 2018, 143: 1079–1084

[24] Ding H, Peng G, Mo S, Ma D, Sharshir S W, Yang N. Ultra-fast vapor generation by a graphene nano-ratchet: a theoretical and simulation study. Nanoscale, 2017, 9(48): 19066–19072

[25] Chiou J S, Yang S, Chen C K. Laminar film condensation inside a horizontal elliptical tube. Applied Mathematical Modelling, 1994, 18(6): 340–346

[26] Churchill S W, Bernstein M. A correlating equation for forced convection from gases and liquids to a circular cylinder in crossflow. Journal of Heat Transfer, 1977, 99(2): 300–306

[27] El-Dessouky H T, Ettouney H M. Fundamentals of Salt Water Desalination. Elsevier Science, 2002

Acknowledgments

This work was financially supported by the National Science Foundation in US (award #1706777) and China Scholarship Council.

RIGHTS & PERMISSIONS

2019 Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature