摘要
基于加湿除湿(HDH)原理,搭建在低温常压下运行的新型脱盐系统,详细介绍系统的结构和工作原理.在相关假设的基础上对加湿除湿过程进行热力学分析,开展空气循环体积流量、进料体积流量和料液温度等操作参数对系统产水性能影响的实验研究.实验结果表明,系统产水量随着料液温度和进料体积流量的增加而增大;与预期相反,系统产水量随空气循环体积流量的增加而先增大后减小;当进料体积流量为60 L/h、料液温度为57°C、空气循环体积流量为180 m~3/h时,系统最大产水量和脱盐率分别达到1.7 kg/h、大于99.99%;当料液温度为38°C时,系统最大造水比和单位体积产水能耗分别为3.8、166 kW·h/m~3.由于具有结构紧凑、模块化设计、操作简单、维护成本低、可以与可再生能源结合等特点,该系统在海水淡化领域颇具竞争力.上述研究表明,该系统虽然有很大的提升空间,但很有希望应用于分散式小规模淡水生产.
A novel desalination system operated at low temperature and atmospheric pressure was constructed based on the mechanism of the humidification-dehumidification(HDH) process. The configuration and working principle of the system were described. The thermodynamic theories of the HDH process were analyzed based on assumptions.The effect of the operating parameters on the performance of the desalination system was analyzed, including the air circulation flow rate, the feed flow rate and the solution temperature. The experimental results indicated that the water yield of the system increased with the solution temperature and the feed flow rate. The water yield was observed to increase first and then decrease by increasing air circulation rate contrary to expectation. At the feed flow rate of 60 L/h, the feed temperature of 57 °C, and the air circulation rate of 180 m~3/h, the maximum yield and salt rejection ratio of the system can reach 1.7 kg/h and more than 99.99%, respectively. When the feed temperature is38 °C, the maximum gained output ratio and specific thermal energy consumption of the system can reach about 3.8 and 166 kW·h/m~3, respectively. It's a competitive technology for the seawater desalination field due to the advantages of compact structure, modular design, easy operability, low maintenance cost, and great compatibility with renewable energy. Results show that the proposed system has great promise for decentralized small-scale water production applications, although it still has much room to be improved.
引文
[1]郑智颖,李凤臣,李倩,等.海水淡化技术应用研究及发展现状[J].科学通报,2016,61(21):2344-2370.ZHENG Zhi-ying,LI Feng-chen,LI Qian,et al.State-of-the-art of R&D on seawater desalination technology(in Chinese)[J].Chinese Science Bulletin,2016,61(21):2344-2370.
[2]冯厚军,谢春刚.中国海水淡化技术研究现状与展望[J].化学工业与工程,2010,27(2):103-109.FENG Hou-jun,XIE Chun-gang.Status and prospect of Chinese seawater desalination technology[J].Chemical Industry and Engineering,2010,27(2):103-109.
[3]高从堦.海水淡化及海水与苦咸水利用发展建议[M].北京:高等教育出版社,2007.
[4]GREENLEE L F,LAWLER D F,FREEMAN B D,et al.Reverse osmosis desalination:water sources,technology,and today's challenges[J].Water Research,2009,43(9):2317-2348.
[5]ZHU A,CHRISTOFIDES P D,COHEN Y.Energy consumption optimization of reverse osmosis membrane water desalination subject to feed salinity fluctuation[J].Industrial and Engineering Chemistry Research,2009,48(21):9581-9589.
[6]SPIEGLER K S,LAIRD A D K.Principles of desalination[M].New York:Academic Press,1980.
[7]上海交通大学.喷雾蒸发空气加湿除湿式太阳能海水淡化装置:20101009740 X[P].2010-10-15.
[8]AL-ENEZI G,ETTOUNEY H,FAWZY N.Low temperature humidification dehumidification desalination process[J].Energy Conversion and Management,2006,47(4):470-484.
[9]NARAYAN G P,LIENHARD J H.Humidification dehumidification desalination[J].Desalination and Water Treatment,2010,16(1-3):339-353.
[10]陶钧,宫建国,曾胜,等.增湿去湿海水淡化技术的研究进展[J].化工进展,2012,31(7):1419-1424.TAO Jun,GONG Jian-guo,ZENG Sheng,et al.Research progress of humidificationdehumidification process[J].Chemical Industry and Engineering Process,2012,31(7):1419-1424.
[11]郑宏飞,何开岩,陈子乾.太阳能海水淡化技术[M].北京:北京理工大学出版社,2015.
[12]NARAYAN G P,SHARQAWY M H,SUMMERS EK,et al.The potential of solar-driven humidification dehumidification desalination for small-scale decentralized water production[J].Renewable and Sustainable Energy Reviews,2010,14(4):1187-1201.
[13]PAREKH S,FARID M M,SELMAN J R,et al.Solar desalination with a humidification-dehumidification technique:a comprehensive technical review[J].Desalination,2004,160(2):167-186.
[14]ESLAMIMANESH A,HATAMIPOUR M S.Economical study of a small-scale direct contact humidification-dehumidification desalination plant[J].Desalination,2010,250(1):203-207.
[15]MISTRY K H,MITSOS A,JOHN H L V.Optimal operating conditions and configurations for humidification dehumidification desalination cycles[J].International Journal of Thermal Sciences,2011,50(5):779-789.
[16]ZHANI K,BACHA H B.Experimental investigation of a new solar desalination prototype using the humidification dehumidification principle[J].Renewable Energy,2010,35(11):2610-2617.
[17]NAWAYSEH N K,FARID M M,AL-HALLAJ S,et al.Solar desalination based on humidification process-I.evaluating the heat and mass transfer coefficients[J].Energy Conversion and Management,1999,40(13):1423-1439.
[18]FARSAD S,BEHZADMEHR A.Analysis of a solar desalination unit with humidification-dehumidification cycle using DoE method[J].Desalination,2011,278(1):70-76.
[19]DAI Y J,ZHANG H F.Experimental investigation of a solar desalination unit with humidification and dehumidification[J].Desalination,2000,130(2):169-175.
[20]原郭丰,赵子竞,JOHANSON J B,et al.雾化加湿除湿海水淡化中蒸发过程实验研究[J].太阳能学报,2016,37(12):3214-3218.YUAN Guo-feng,ZHAO Zi-jing,JOHANSON J B,et al.Experiment research of evaporation process in spray atomization humidification-dehumidification desalination[J].Acta Energiae Solaris Sinica,2016,37(12):3214-3218.
[21]常泽辉,郑宏飞,侯静,等.两级多效太阳能增湿除湿苦咸水淡化装置的性能研究[J].北京理工大学学报,2015,35(1):27-33.CHANG Ze-hui,ZHENG Hong-fei,HOU Jing,et al.Performance of a two-stage multi-effect solar desalination system based on humidificationdehumidification process[J].Transactions of Beijing Institute of Technology,2015,35(1):27-33.
[22]刘忠,曾胜,程涛涛,等.多效鼓泡蒸发太阳能海水淡化系统的稳态实验研究[J].太阳能学报,2012,33(3):380-385.LIU Zhong,ZENG Sheng,CHENG Tao-tao,et al.Steady experimental study on a solar distillation plant characterized with multi-effect bubbling evaporator[J].Acta Energiae Solaris Sinica,2012,33(3):380-385.
[23]李正良,郑宏飞,陈子乾,等.降膜蒸发多效回热吸收式太阳能海水淡化系统的实验研究[J].太阳能学报,2007,28(11):1188-1193.LI Zheng-liang,ZHENG Hong-fei,CHEN Zi-qian,et al.Experimental study on an absorption type solar desalination system with falling film evaporation and multi-effects regeneration[J].Acta Energiae Solaris Sinica,2007,28(11):1188-1193.
[24]EL-DESSOUKY H T,ETTOUNEY H M.Fundamentals of salt water desalination[M].Netherlands:Elsevier,2002:23-41.
[25]XIAO G,WANG X,NI M,et al.A review on solar stills for brine desalination[J].Applied Energy,2013,103(1):642-652.
[26]DUONG H C,COOPER P,NELEMANS B,et al.Evaluating energy consumption of air gap membrane distillation for seawater desalination at pilot scale level[J].Separation and Purification Technology,2016,166:55-62.