بهبود عملکرد سامانۀ نمک‌زدایی جذب سطحی با بازیابی حرارت بستر احیا شده

نویسنده

دانشگاه اصفهان

چکیده

در اینپژوهش روشی برای بازیابی حرارتی گرمای بستر احیا شدۀ یک سامانۀ نمک­زدایی جذب سطحی با دو بستر ارائه شدهاست. اثر بازیابی حرارتی بسترها بر عملکرد سامانه بررسی شدهاست. اثر دمای آب گرم­کننده و آب خنک­کنندۀ ورودی به بستر و چگالنده بر عملکرد سامانه و بازیابی حرارتی آن بررسی شده­است. در دمای آب خنک‌کننده ثابت، افزایش دمای آب گرم­کننده میزان آب تولیدی را افزایش می‌دهد و بر انرژی مصرفی
تأثیر چشمگیری ندارد؛ به
عنوان مثال در دمای آب خنک‌کننده 20 درجۀ سلسیوس، با افزایش دمای آب گرم­کننده  از 50 تا 90 درجۀ سلسیوس آب تولیدی 75/2 برابر می­شود، حال آن­که انرژی مصرفی 4/7 درصد کاهش می­یابد. بازیابی حرارتی موجب کاهش انرژی مصرفی سامانه می­شود. با افزایش دمای آب گرم­کننده اثر بازیابی حرارتی افزایش می­یابد. به‌گونه‌ای که درنتیجۀ بازیابی حرارت در آب گرم‌کننده 50 و 90 درجۀ سلسیوس مصرف انرژی سامانه بهترتیب 9/10 و 6/37 درصد کاهش پیدا میکند. افزایش دمای آب خنک‌کنندۀ ورودی به بستر و چگالنده موجب کاهش آب تولیدی و افزایش انرژی مصرفی سامانه می‌شود. اثر دمای آب خنک­کنندۀ ورودی به چگالنده بر آب تولیدی و انرژی مصرفی بیشتر از دمای آب خنک­کنندۀ ورودی به بستر است. با افزایش دمای آب خنک‌کننده صرفه­جویی انرژی در اثر بازیابی حرارتی کاهش می­یابد. در دمای آب خنک‌کننده 10 درجۀ سلسیوس، بازیابی حرارتی مصرف انرژی سامانه را حدود 47 درصد کاهش می­دهد؛ حال آن­که این مقدار در 23 درجۀ سلسیوس حدود 12 درصد است. اثر دمای آب خنک­کنندۀ ورودی به چگالنده از دمای آب خنک­کنندۀ ورودی به بستر بیشتر است. با افزایش دماهای آب خنک­کنندۀ ورودی به چگالنده از 15 به 35 درجۀ سلسیوس، صرفه­جویی انرژی مصرفی در اثر بازیابی حرارتی از 7/53 تا 3/9 درصد کاهش می‌یابد.

کلیدواژه‌ها


عنوان مقاله [English]

Improvement of the Performance of an Adsorption Desalination System with Regenerated Bed Heat Recovery

نویسنده [English]

  • M. Hojjat
University of Isfahan
چکیده [English]

This study aims to propose a method for the thermal recovery of regenerated bed in a two-bed adsorption desalination system. It investigates the affection of thermal recovery, heating water temperature, and cooling water temperature entering the bed and condenser on the performance of the system. The analysis demonstrated that at a constant temperature of cooling water, the amount of water that is produced increases by raising the temperature of hot water and the energy consumption does not change significantly. For example, at a cooling water temperature of 20 °C, by increasing the temperature of heating water from 50 to 90 °C, the water that is produced is 3.75 times more and the energy consumption is reduced by 7.4 %. Heat recovery reduces the energy consumption of the system. As the temperature of the hot water increases, the effect of thermal recovery increases. As a result of heat recovery at a heating water temperature of 50 and 90 °C, the energy consumption of the system decreases by 10.9 % and 37.6 %, respectively. Increasing the temperature of the inlet cooling water to the bed and the condenser reduces the production of water and increases the energy consumption of the system. The effect of the temperature of cooling water entering the condenser on the water that is produced and the energy consumption is greater than that of the cooling water entering the bed. As the cooling water temperature increases, the energy-saving as a result of thermal recovery decreases. For example, At a cooling water temperature of 10 °C, thermal recovery reduces the energy consumption of the system by about 47 %, while at 23°C it is about 12 %. Again the effect of cooling water temperature that enters the condenser is more than that enters the bed. By increasing the temperature of cooling water entering the condenser from 15 to 35°C, energy savings due to the heat recovery reduces from 53.7 to 9.3 %.
 

کلیدواژه‌ها [English]

  • Desalination
  • Adsorption
  • Heat Recovery
  • Silica gel-Water
  • Isotherm

 

[1]        Betts, K., "Technology Solutions: Desalination, desalination everywhere", Environ Sci Technol,
Vol. 38, (13), pp. 246A-7A, (2004).
[2]        Tamburini, A., Tedesco, M., Cipollina, A., Micale, G., Ciofalo, M., Papapetrou, M., Van Baak, W., Piacentino, A., "Reverse electrodialysis heat engine for sustainable power production", Appl Energy,
Vol. 206, pp. 1334-1353, (2017).
[3]        Olkis, C., Santori, G., Brandani, S., "An Adsorption Reverse Electrodialysis system for the generation of electricity from low-grade heat", Appl Energy,
Vol. 231, pp. 222-234, (2018).
[4]        Giacalone, F., Olkis, C., Santori, G., Cipollina, A., Brandani, S., Micale, G., "Novel solutions for closed-loop reverse electrodialysis: Thermodynamic characterisation and perspective analysis", Energy, Vol. 166, pp. 674-689, (2019).
[5]        Bevacqua, M., Tamburini, A., Papapetrou, M., Cipollina, A., Micale, G., Piacentino, A., "Reverse electrodialysis with NH4HCO3-water systems for heat-to-power conversion", Energy, Vol. 137,
pp. 1293-1307, (2017).
[6]        Zheng, X., Chen, D., Wang, Q., Zhang, Z., "Seawater desalination in China: Retrospect and prospect", Chem Eng J, Vol. 242, pp. 404-413, (2014).
[7]        El-Dessouky, H. T., Ettouney, H. M., Al-Roumi, Y., "Multi-stage flash desalination: present and future outlook", Chem Eng J, Vol. 73, (2), pp. 173-190, (1999).
[8]        Palenzuela, P., Hassan, A. S., Zaragoza, G., Alarcón-Padilla, D. -C., "Steady state model for multi-effect distillation case study: Plataforma Solar de Almería MED pilot plant", Desalination, Vol. 337, pp. 31-42, (2014).
[9]        Al-Karaghouli, A., Kazmerski, L. L., "Energy consumption and water production cost of conventional and renewable-energy-powered desalination processes", Renewable Sustainable Energy Rev, Vol. 24, pp. 343-356, (2013)
[10]      Ng, K. C., Shahzad, M. W., Son, H. S., Hamed, O. A., "An exergy approach to efficiency evaluation of desalination", Appl Phys Lett, Vol. 110, (18),
p. 184101, (2017).
[11]      Shahzad, M. W., Burhan, M., Ang, L., Ng, K. C., "Energy-water-environment nexus underpinning future desalination sustainability", Desalination,
Vol. 413, pp. 52-64, (2017).
[12]      Ng, K. C., Thu, K., Kim, Y., Chakraborty, A., Amy, G., "Adsorption desalination: An emerging low-cost thermal desalination method", Desalination, Vol. 308, pp. 161-179, (2013).
[13]      Wang, X., Ng, K. C., "Experimental investigation of an adsorption desalination plant using low-temperature waste heat", Appl Therm Eng, Vol. 25, (17), pp. 2780-2789, (2005)
[14]      El-Sharkawy, I. I., Thu, K., Ng, K. C., Saha, B. B., Chakraborty, A., Koyama, S., "Performance improvement of adsorption desalination plant: experimental investigation", International Review of Chemical Engineering, Vol. 6, (3), pp. 127-132, (2014).
[15]      Wang, X., Ng, K. C., Chakarborty, A., Saha, B. B., "How Heat and Mass Recovery Strategies Impact the Performance of Adsorption Desalination Plant: Theory and Experiments", Heat Transfer Eng,
Vol. 28, (2), pp. 147-153, (2007).
[16]      Mitra, S., Kumar, P., Srinivasan, K., Dutta, P., "Performance evaluation of a two-stage silica gel + water adsorption based cooling-cum-desalination system", Int J Refrig, Vol. 58,
pp. 186-198, (2015).
 
 
 
 
[17]      Alsaman, A. S., Askalany, A. A., Harby, K., Ahmed, M. S., "Performance evaluation of a solar-driven adsorption desalination-cooling system", Energy, Vol. 128, pp. 196-207, (2017).
[18]      Vodianitskaia, P. J., Soares, J. J., Melo, H., Gurgel, J. M., "Experimental chiller with silica gel: Adsorption kinetics analysis and performance evaluation", Energ Convers Manage, Vol. 132, pp. 172-179, (2017).
[19]      Sapienza, A., Gullì, G., Calabrese, L., Palomba, V., Frazzica, A., Brancato, V., La Rosa, D., Vasta, S., Freni, A.,Bonaccorsi, L.,Cacciola, G., "An innovative adsorptive chiller prototype based on 3 hybrid coated/granular adsorbers", Appl Energy, Vol. 179, pp. 929-938, (2016).
[20]      Chorowski, M., Pyrka, P., "Modelling and experimental investigation of an adsorption chiller using low-temperature heat from cogeneration", Energy, Vol. 92, pp. 221-229, (2015).
[21]      Sharonov, V. E., Aristov, Y. I., "Chemical and adsorption heat pumps: Comments on the second law efficiency", Chem Eng J, Vol. 136, (2), pp. 419-424, (2008).
[22]      Al-Ghouti, M. A., Yousef, I., Ahmad, R., Ghrair, A. M., Al-Maaitah, A. A., "Characterization of diethyl ether adsorption on activated carbon using a novel adsorption refrigerator", Chem Eng J, Vol. 162, (1), pp. 234-241, (2010).
[23]      Wu, J. W., Biggs, M. J., Hu, E. J., "Thermodynamic analysis of an adsorption-based desalination cycle", Chem Eng Res Des, Vol. 88, (12), pp. 1541-1547, (2010).
 
[24]      Wu, J. W., Hu, E. J., Biggs, M. J., "Thermodynamic analysis of an adsorption-based desalination cycle (part II): Effect of evaporator temperature on performance", Chem Eng Res Des, Vol. 89, (10),
pp. 2168-2175, (2011).
[25]      Amirfakhraei, A., Zarei, T., Khorshidi, J., "Performance Improvement of Adsorption Desalination System by Applying Mass and Heat Recovery Processes", Thermal Science and Engineering Progress, Vol., p. 100516, (2020).
[26]      Thu, K., Saha, B. B., Chakraborty, A., Chun, W. G., Ng, K. C., "Study on an advanced adsorption desalination cycle with evaporator–condenser heat recovery circuit", Int J Heat Mass Transfer, Vol. 54, (1), pp. 43-51, (2011).
[27]      Thu, K., Yanagi, H., Saha, B. B., Ng, K. C., "Performance investigation on a 4-bed adsorption desalination cycle with internal heat recovery scheme", Desalination, Vol. 402, pp. 88-96, (2017).
[28]      Ng, K. C., Chua, H. T., Chung, C. Y., Loke, C. H., Kashiwagi, T., Akisawa, A., Saha, B. B., "Experimental investigation of the silica gel–water adsorption isotherm characteristics", Appl Therm Eng, Vol. 21, (16), pp. 1631-1642, (2001).
[29]      Liu, Y., "Some consideration on the Langmuir isotherm equation", Colloids Surf, A, Vol. 274, (1), pp. 34-36, (2006).
[30]      Atkins, P., Paula, J. D., Keeler, J., "Atkins' Physical chemistry". 11th ed., Oxford, Oxford University Press, (2018).