Design and research of MVR parallel double-effect evaporation crystallization system

doi:10.16085/j.issn.1000-6613.2019-0132

Abstract

Abstract:

In the field of industrial waste water treatment, evaporation crystallization technology can recover raw materials for industrial production while carrying out deep treatment. It can realize resource utilization of waste water. The applicability of different types of evaporators is limited in existing research. In response to the above issue, mechanical vapor recompression(MVR) parallel double-effect evaporation crystallization system was proposed, which combined a falling film evaporator with a forced circulation evaporator. After designing the process flow, thermodynamic state of medium in each pipe segment of the system was analyzed. On this basis, mathematical model of the target system was established. It can be used to calculate mass and energy balance of the whole system and related equipment. Energy analysis of the system can also be carried out. In addition to energy analysis, exergy analysis model was also established. Taking sodium sulfate solution with a concentration of 5% at atmospheric pressure as an example, the model calculation was carried out by Matlab software. A three-effect evaporation crystallization system was introduced as a reference system. Results showed that MVR parallel double-effect evaporation crystallization system is much more energy-efficient. Its coefficient of performance(COP) is 21.4 and 82.2% higher than that of the reference system under same working condition. Its unit energy consumption is only 17.6% of the reference system. Meanwhile MVR parallel double-effect evaporation crystallization system has a higher degree of thermodynamic perfection. Its exergy efficiency is 51.5% higher than that of the reference system, and exergy loss is 24.7% lower than that of the reference system. MVR parallel double-effect evaporation crystallization system has great application potential in energy saving.

Key words: waste water, mechanical vapor recompression(MVR), double-effect evaporation, crystallization, balance, performance analysis, exergy

摘要：

利用蒸发法处理工业废水，能够实现废水的资源化利用。本文针对不同类型蒸发器适用范围受限问题，将降膜式蒸发器与强制循环蒸发器联用，提出了机械蒸汽再压缩（MVR）并联双效蒸发结晶系统。首先设计了系统的工艺循环流程并建立数学模型，对该系统及其设备进行质量和能量衡算，并对模型的可行性进行核算。随后建立系统性能的?分析模型，对常压下质量分数为5%的硫酸钠溶液蒸发结晶进行实例计算，并将其与传统三效蒸发结晶系统进行比较。通过综合能量分析与?分析，MVR并联双效蒸发结晶系统的节能程度更大，其效能系数（COP）值为21.4，相同工况下高于传统三效蒸发结晶系统82.2%，而单位能耗仅为传统三效蒸发结晶系统的17.6%；其?效率高于传统三效蒸发结晶系统51.5%，?损失则低于传统三效蒸发结晶系统24.7%，这表明MVR并联双效蒸发结晶系统热力学完善程度更高，在节能方面有较大的推广应用潜力。

关键词: 废水, 机械蒸汽再压缩, 双效蒸发, 结晶, 平衡, 性能分析, ?

CLC Number:

TQ062

Hua JIANG,Ziyao ZHANG,Wuqi GONG. Design and research of MVR parallel double-effect evaporation crystallization system[J]. Chemical Industry and Engineering Progress, 2019, 38(10): 4461-4469.

姜华,张子尧,宫武旗. MVR并联双效蒸发结晶系统设计及研究[J]. 化工进展, 2019, 38(10): 4461-4469.

Figures/Tables 10

References 32

1	全球环保研究网 . 工业废水处理行业发展研究报告(2018) [R/OL]. 2018-09-25. .
	Research GEP . Report on the development of industrial waste water treatment industry(2018) [R/OL]. 2018-09-15. .
2	高丽丽, 张琳, 杜明照 . MVR蒸发与多效蒸发技术的能效对比分析研究[J]. 现代化工, 2012, 32(10): 84-86.
	GAO Lili , ZHANG Lin , DU Mingzhao . Energy efficiency comparative analysis on MVR and multi-effect evaporation technology [J]. Modern Chemical Industry, 2012, 32(10): 84-86.
3	赵远扬, 刘广彬, 李连生, 等 . 机械蒸汽再压缩系统的性能分析[J]. 流体机械, 2017, 45(6): 16-20, 60.
	ZHAO Yuanyang , LIU Guangbin , LI Liansheng , et al . Performance analysis on mechanical vapor recompression system [J]. Fluid Machinery, 2017, 45(6): 16-20, 60.
4	HAN Dong , PENG Tao , HE Weifeng , et al . Advanced energy saving in the evaporation system of ammonium sulfate solution with self-heat recuperation technology [J]. Energy Procedia, 2014, 61: 131-136.
5	李帅旗, 王汉治, 黄冲, 等 . 基于MVR技术的单级双效蒸发浓缩系统性能分析[J]. 新能源进展, 2018, 6(1): 36-41.
	LI Shuaiqi , WANG Hanzhi , HUANG Chong , et al . Performance analysis of single-stage and double-effect evaporative concentration system based on MVR technology [J]. Advances in New and Renewable Energy, 2018, 6(1): 36-41.
6	顾承真, 闵兆升, 洪厚胜 . 机械蒸汽再压缩蒸发系统的性能分析[J]. 化工进展, 2014, 33(1):30-35.
	GU Chengzhen , MIN Zhaosheng , HONG Housheng . Performance analysis of mechanical vapor recompression evaporation system [J]. Chemical Industry and Engineering Progress, 2014, 33(1):30-35.
7	顾承真, 洪厚胜, 张志强, 等 . 罗茨压缩机驱动MVR热泵系统的实验研究[J]. 化工进展, 2015, 34(6):1602-1606,1612.
	GU Chengzhen , HONG Housheng , ZHANG Zhiqiang , et al . Experimental study of mechanical vapor recompression of heat pump driven by roots compressor [J]. Chemical Industry and Engineering Progress, 2015, 34(6):1602-1606, 1612.
8	ETTOUNEY H . Design of single-effect mechanical vapor compression [J]. Desalination, 2006, 190: 1-15.
9	MABROUK A A , NAFEY A S , FATH H E S . Analysis of a new design of a multi-stage flash-mechanical vapor compresion desalination process [J]. Desalination, 2007, 204: 482-500.
10	SHEN Jiubing , XING Ziwen , WANG Xiaolin , et al . Analysis of a single-effect mechanical vapor compression desalination system using water injected twin screw compressors [J]. Desalination, 2014, 333: 146-153.
11	越云凯, 吴小华, 张振涛 . MVR海水淡化系统运行特性分析与优化[J]. 工程热物理学报, 2018, 39(9): 1985-1990.
	YUE Yunkai , WU Xiaohua , ZHANG Zhentao . Operation characteristic analysis and optimization of MVR seawater desalination system [J]. Journal of Engineering Thermophysics, 2018, 39(9): 1985-1990.
12	石成君, 周亚素, 孙韶, 等 . 机械蒸汽再压缩蒸发技术高盐度废水处理系统的性能分析[J]. 水处理技术, 2013, 39(12):63-68.
	SHI Chengjun , ZHOU Yasu , SUN Shao , et al . Performance and analysis of mechanical vapor recompression for high salinity wastewater desalination system [J]. Technology of Water Treatment, 2013, 39(12): 63-68.
13	ZHOU Yasu , SHI Chengjun , DONG Guoqiang . Analysis of a mechanical vapor recompression wastewater distillation system [J]. Desalination, 2014, 353: 91-97.
14	王汉治, 李帅旗, 黄冲, 等 . 喷气增焓型单级MVR蒸发结晶系统性能分析[J]. 化工进展, 2018, 37(9): 3312-3319.
	WANG Hanzhi , LI Shuaiqi , HUANG Chong , et al . Performance analysis of single-effect MVR evaporative crystallization system using vapor injected compressor [J]. Chemical Industry and Engineering Progress, 2018, 37(9): 3312-3319.
15	AI Songhui , WANG Baolong , LI Xianting , et al . Numerical analysis on the performance of mechanical vapor recompression system for strong sodium chloride solution enrichment [J]. Applied Thermal Engineering, 2018, 137: 386-394.
16	NAFEY A S , FATH H E S , MABROUK A A . Thermoeconomic design of a multi-effect evaporation mechanical vapor compression (MEE-MVC) desalination process [J]. Desalination, 2008, 230:1-15.
17	JAMIL M A , ZUBAIR S M . Design and analysis of a forward feed multi-effect mechanical vapor compression desalination system: an exergo-economic approach [J]. Energy, 2017, 140: 1107-1120.
18	高磊, 张凯, 董冰, 等 . 螺杆水蒸气压缩机的MVR系统在碱回收中的应用[J]. 化工进展, 2014, 33(11): 3112-3117.
	GAO Lei , ZHANG Kai , DONG Bing , et al . Research of MVR system with twin-screw vapor compressor in lye recovery [J]. Chemical Industry and Engineering Progress, 2014, 33(11): 3112-3117.
19	刘军, 张冲, 杨鲁伟, 等 . 夹套式MVR热泵蒸发浓缩系统性能分析[J]. 化工学报, 2015, 66(5): 1904-1911.
	LIU Jun , ZHANG Chong , YANG Luwei , et al . Performance analysis of jacketed MVR heat pump evaporation concentration system [J]. CIESC Journal, 2015, 66(5): 1904-1911.
20	LIANG Lin , HAN Dong , MA Ran , et al . Treatment of high-concentration wastewater using double-effect mechanical vapor recompression [J]. Desalination, 2013, 314: 139-146.
21	梁林 . 处理高浓度含盐废水的机械蒸汽再压缩系统设计及性能研究[D]. 南京: 南京航空航天大学, 2013.
	LIANG Lin . Design and performance research of mechanical vapor recompression system for treating high concentration saline wastewater [D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2013.
22	郝帅 . 机械蒸汽再压缩技术4种典型蒸发器的比较[J]. 中国乳品工业, 2017, 45(4): 41-43.
	HAO Shuai . Comparation of four kinds of typical evaporators in the mechanical vapour recompression technology [J]. China Dairy Industry, 2017, 45(4): 41-43.
23	刘德亮 . 机械蒸汽再压缩蒸发结晶系统性能研究[D]. 杭州: 浙江工业大学, 2013.
	LIU Deliang . Performance research of mechanical vapor recompression evaporation and crystallization system [D]. Hangzhou: Zhejiang University of Technology, 2013.
24	朱跃钊, 廖传华, 史勇春 . 传热过程与设备[M]. 北京: 中国石化出版社, 2008: 113, 284.
	ZHU Yuezhao , LIAO Chuanhua , SHI Yongchun . Heat transfer process and equipment [M]. Beijing: China Petrochemical Press, 2008: 113, 284.
25	焦冬生 . 机械压汽蒸馏海水淡化系统的可用能分析[J]. 太阳能学报, 2008, 29(10): 1197-1203.
	JIAO Dongsheng . Exergy analysis of a experimental mechanic vapor compression distillation system [J]. Acta Energiae Solaris Sinica, 2008, 29(10):1197-1203.
26	NAFEY A S , FATH H E S , MABROUK A A . Exergy and thermoeconomic evaluation of MSF process using a new visual package [J]. Desalination, 2006, 201: 224-240.
27	MABROUK A A , NAFEY A S , FATH H E S , et al . Analysis of a new design of a multi-stage flash-mechanical vapor compression desalination process [J]. Desalination, 2007, 204: 482-500.
28	大连理工大学 . 化工原理:上册[M]. 2版. 北京:高等教育出版社, 2009: 337-338.
	Dalian University of Technology . Unit operation of chemical engineering: Volume 1[M]. 2nd edition.Beijing: Higher Education Press, 2009: 337-338.
29	石成君 . 机械蒸汽再压缩蒸发技术在高盐度废水处理中的性能研究[D]. 上海: 东华大学, 2014.
	SHI Chengjun . Research of mechanical vapor recompression evaporation technology in high salinity wastewater treatment system [D]. Shanghai: Donghua University, 2014.
30	庞卫科, 林文举, 潘麒麟, 等 . 离心风机驱动机械蒸汽再压缩热泵系统的性能分析[J]. 机械工程学报, 2013, 49(12):142-146.
	PANG Weike , LIN Wenju , PAN Qilin , et al . Performance analysis of mechanical vapor recompression heat pump driven by centrifuge fan [J]. Journal of Mechanical Engineering, 2013, 49(12): 142-146.
31	陈丽丽 . 复杂水溶液体系通用活度测定设备的研制及其实际应用[D]. 长沙: 湖南大学, 2015.
	CHEN Lili . A general apparatus research for the determination of water activity applied in complex solution system [D]. Changsha: Hunan University, 2015.
32	邓润亚 . 海水淡化系统能量综合利用与经济性研究[D]. 北京: 中国科学院研究生院, 2009.
	DENG Runya . Energy comprehensive utilization and economy study on seawater desalination system [D]. Beijing: Graduate School of the Chinese Academy of Sciences, 2009.

名称及单位	文献[29]	计算	误差/%
原料液温度t ₀/℃	25	25	—
进料流量F ₀/kg·h^-1	23.3	23.3	—
进料质量分数w ₀/%	2	2	—
出料质量分数w ₁/%	10	10	—
蒸发温度t ₁/℃	80.1	80.1	—
蒸发量W/kg·h^-1	18.6	18.6	—
蒸发器传热温差Δt/℃	5	5	—
蒸发器换热面积S ₁/m²	1.38	1.44	-4.3
预热器换热面积S ₃/m²	0.17	0.16	5.8
蒸发器换热量Q ₁/kW	13.07	13.04	0.2
预热器换热量Q ₀/kW	1.16	1.22	-5.2
压缩机功率N ₁/kW	1	0.331	66.9

名称及单位	文献[29]	计算	误差/%
原料液温度t ₀/℃	25	25	—
进料流量F ₀/kg·h^-1	23.3	23.3	—
进料质量分数w ₀/%	2	2	—
出料质量分数w ₁/%	10	10	—
蒸发温度t ₁/℃	80.1	80.1	—
蒸发量W/kg·h^-1	18.6	18.6	—
蒸发器传热温差Δt/℃	5	5	—
蒸发器换热面积S ₁/m²	1.38	1.44	-4.3
预热器换热面积S ₃/m²	0.17	0.16	5.8
蒸发器换热量Q ₁/kW	13.07	13.04	0.2
预热器换热量Q ₀/kW	1.16	1.22	-5.2
压缩机功率N ₁/kW	1	0.331	66.9

设计任务参数	数值
进料质量分数w ₀/%	5
出料质量分数w ₁/%	29
进料量F ₀/kg·h^-1	15900
蒸发量W/kg·h^-1	15000
蒸发温度t ₁/℃	100
压缩机饱和温升/℃	12

设计任务参数	数值
进料质量分数w ₀/%	5
出料质量分数w ₁/%	29
进料量F ₀/kg·h^-1	15900
蒸发量W/kg·h^-1	15000
蒸发温度t ₁/℃	100
压缩机饱和温升/℃	12

编号	温度 /℃	质量分数/%	流量 /kg·h^-1	焓值 /kJ·kg^-1	?值 /kW	比? /kJ·kg^-1	介质类型
1	20	5	15900	—	484.5	109.7	溶液
2	100	5	15900	—	495.5	112.2
3	102.5	29.8	2741.4	—	35.4	46.5
4	102.5	29.8	2877.7	—	38.9	48.7
5	102.5	29.8	136.3	—	1.8	46.5
6	102.5	—	900	—	15	53.6	晶浆
7	—	—	763.7	—	13.2	62.2	晶体
8	114.5	—	16617	2697.9	2581.6	559.3	蒸汽
9	114.5	—	14474.5	2697.9	2248.8	559.3
10	114.5	—	2025.5	2697.9	314.7	559.3
11	102.5	—	14577	2679.5	2025.8	500.3
12	102.5	—	2040	2679.5	283.5	500.3
13	102.5	—	16617	2679.5	2309.3	500.3
14	140.6	—	16617	2752.4	2646	573.2
15	102.5	—	14474.5	429.8	210.5	52.4	凝水
16	102.5	—	2025.5	429.8	29.5	52.4
17	102.5	—	16500	429.8	240	52.4
18	26.1	—	16500	109.4	8.3	1.8
19	26.1	—	349.9	109.4	0.2	1.8