Analysis of mass and heat transfer process of packing evaporator in HD low temperature evaporation system

doi:10.16085/j.issn.1000-6613.2018-1462

Abstract

Abstract:

In this paper, the evaporative mass and heat transfer process and the two-phase flow characteristics of the packing evaporator were studied. The method of coupling discrete and continuous phases in computational fluid dynamics (CFD) was used to simulate mass and heat transfer of the evaporative process in the internal channels of the structured packing. The two-phase mass and heat transfer process in the packing evaporator and visualization of the droplet flow were realized. A new simulation method for studying the flow of gas-liquid two-phase in structured packing was provided. By comparing with the experimental results, the turbulence model of RNG k-ε was determined, and the mass and heat transfer and flow of gas-liquid two-phase inside the structured packing were analyzed. By changing the plate spacing of structured packing, the effect of gas-liquid two-phase mass and heat transfer and droplet movement inside the packing was simulated and analyzed. It was found that with the increase of plate spacing, the pressure drop inside the packing was gradually reduced, the content of water vapor in the outlet air was continuously reduced, the evaporation rate of the droplets was reduced, the difference between the droplet inlet and outlet quality was reduced, and the temperature at the outlet of the gas phase decreased. The efficiency of evaporation of mass transfer and heat transfer decreased. As the gas velocity increases, the content of water vapor in the outlet air decreased, the evaporation rate of the droplet increased, and the temperature at the outlet of the gas phase decreased. The efficiency of evaporation of mass transfer and heat transfer in gas-liquid two-phase decreased.

Key words: packing evaporator, structured packing, numerical simulation, plate spacing, mass and heat transfer

摘要：

通过研究系统中填料蒸发器的蒸发传质传热过程以及两相流动特性，采用计算流体力学（computational fluid dynamics，CFD）中离散相与连续相耦合的方法来模拟规整填料内部通道的蒸发传质传热过程，实现了填料蒸发器中两相传质传热的过程以及液滴流动的可视化，为研究气液两相在规整填料内的流动提供了一种模拟方法。通过与实验结果的比较，最终选用RNG k-ε湍流模型来分析规整填料内部气液两相传质传热以及流动情况。数值模拟研究了规整填料板间距对填料内部气液两相传质传热以及液滴运动影响，发现随着板间距的增大，填料内部压力降逐渐降低，出口空气中水蒸气的含量不断减小，液滴蒸发速率降低，液滴进出口质量差减小，气相出口温度逐渐降低，蒸发传质传热效率降低。随着气速的增大，出口空气中水蒸气的含量不断减小，液滴蒸发速率增加，气相出口温度降低，气液两相传质传热效率降低。

关键词: 填料蒸发器, 规整填料, 数值模拟, 板间距, 传质传热

CLC Number:

TQ028

Huixin YUAN, Weiwen LUO, Shuangcheng FU, Mingjia LU, Nanhua DING. Analysis of mass and heat transfer process of packing evaporator in HD low temperature evaporation system[J]. Chemical Industry and Engineering Progress, 2019, 38(05): 2132-2141.

袁惠新, 雒维文, 付双成, 陆明佳, 丁南华. HD低温蒸发系统中填料蒸发器传质传热的分析[J]. 化工进展, 2019, 38(05): 2132-2141.

Figures/Tables 18

波纹板填料参数	尺寸数值
填料长度/mm	250
填料宽度/mm	250
板间距/mm	1.25
波宽2B/mm	8
波高h/mm	5

水蒸气含量/g?kg^-1	误差/%
水蒸气含量/g?kg^-1	standard $k - ε$ +SWF	RNG $k - ε$ +SWF	realizable $k - ε$ +SWF	standard $k - ε$ +EWT	RNG $k - ε$ +EWT	realizable $k - ε$ +EWT
2.65	3.958	3.278	3.927	3.293	3.233	3.293
2.77	0.287	0.014	0.287	0.086	0.086	0.086
2.98	0.304	0.359	0.331	0.470	0.414	0.470
3.11	3.179	3.179	3.179	3.207	3.207	3.207
3.69	1.455	1.350	1.479	1.338	1.338	1.362
平均误差	1.837	1.636	1.841	1.679	1.656	1.683

水蒸气含量/g?kg^-1	误差/%
水蒸气含量/g?kg^-1	standard $k - ε$ +SWF	RNG $k - ε$ +SWF	realizable $k - ε$ +SWF	standard $k - ε$ +EWT	RNG $k - ε$ +EWT	realizable $k - ε$ +EWT
2.65	3.958	3.278	3.927	3.293	3.233	3.293
2.77	0.287	0.014	0.287	0.086	0.086	0.086
2.98	0.304	0.359	0.331	0.470	0.414	0.470
3.11	3.179	3.179	3.179	3.207	3.207	3.207
3.69	1.455	1.350	1.479	1.338	1.338	1.362
平均误差	1.837	1.636	1.841	1.679	1.656	1.683

References 18

1	王树楹.现代填料塔技术指南[M].北京：中国石化出版社,1998．
	WANGS Y. Technical guide for modern packing towers [M].Beijing: China Petrochemical Press, 1998.
2	袁惠新,冯骉.分离工程[M].北京：中国石化出版社,2002．
	YUANH X, FENGB. Separation engineering[M].Beijing China Petrochemical Press, 2002.
3	NUSSELTW. Die oberflaechenkondensateion des wasserdampfes[J].Zeitschrift Des Vereines Deutscher Ingenieure，1916，60：569-575.
4	HOKEP J, WESSELINGHJ A, ZUIDERWEGF J. Small scale and large scale liquid maldistribution in packed columns[J]. Chemical Engineering Research & Design, 1986, 64(6):431-449.
5	OLUJICZ. Development of a complete simulation model for predicting the hydraulic and separation performance of distillation columns equipped with structured packings[J]. Chem. Biochem. Eng. Q, 1997, 11(1)31-46.
6	STOTERF, OLUJICZ，GRAAUW JDE. Liquid distribution performance modelling and evaluation[C]//AIChE Annual Meeting, Los Angeles, 1991 November17-22, paper No 62f.
7	张鹏,刘春江,袁希钢.规整填料塔液相流动的计算流体力学模拟[J].化工学报, 2004, 55(8)：1369-1373．
	ZHANGP, LIUC J, YUANX G. Computational fluid dynamics simulation of liquid flow in a structured packed column[J].CIESC Journal, 2004, 55(8)：1369-1373．
8	何杰, 高腾飞, 罗文媛,等. 规整填料塔内气-液两相并流流动的CFD研究[J]. 化学工业与工程, 2017, 34(1):76-83.
	HEJ, GAOT F, LUOW Y, et al. CFD study on gas-liquid two-phase cocurrent flow in structured packed column[J]. Chemical Industry and Engineering, 2017, 34(1):76-83.
9	HAROUNY, RAYNALL, LEGENDRED. Mass transfer and liquid hold-up determination in structured packing by CFD[J]. Chemical Engineering Science, 2012, 75:342-348.
10	SINGHR K, GALVINJ E, SUNX. Hydrodynamics of the rivulet flow over corrugated sheet used in structured packings[J]. International Journal of Greenhouse Gas Control, 2017, 64:87-98.
11	LAUNDERB E, SPALDINGD B. Lectures in mathematical models of turbulence[M]. Academic Press, 1972.
12	YAKHOTV, ORSZAGS A. Renormalization group analysis of turbulence. Ⅰ. Basic theory[J]. Journal of Scientific Computing, 1986, 1(1):3-51.
13	SHIHT H, LIOUW W, SHABBIRA, et al. A new k -ε eddy viscosity model for high reynolds number turbulent flows[J]. Computers Fluids, 1995, 24(3):227-238.
14	ZHANGL, HIHARAE, MATSUOKAF, et al. Experimental analysis of mass transfer in adiabatic structured packing dehumidifier/regenerator with liquid desiccant[J]. International Journal of Heat & Mass Transfer, 2010, 53(13):2856-2863.
15	LUDWIGE E, Applied process design for chemical and petrochemical plants.[M].2nd ed.Houston,Texas: Gulf Publishing Company,1997.
16	柴诚敬,贾绍义.化工原理[M].3版.北京：高等教育出版社,2016. CHAI C J,JIA S Y,Principle of chemical industry[M].3rd ed.Beijing: Higher Education Press, 2016.
17	谷芳.规整填料局部流动与传质的计算流体力学研究[D]. 天津：天津大学, 2004.
	GUF. Computational fluid dynamics study on local flow and mass transfer of structured packing[D]. Tianjin： Tianjin University, 2004.
18	YANNIOTISS, XERODEMASK. Air humidification for seawater desalination[J]. Desalination, 2003, 158(1):313-319.

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