Effect of axial heat conduction on heat transfer performance of plate fin heat exchanger under different thermal boundary condition

doi:10.11949/0438-1157.20200922

Abstract

Abstract:

Based on MATLAB program and by implementing the distributed parameter method, the 2-D model of reverse-flow plate fin heat exchanger(PFHE) was constructed. The numerical results were compared with the experimental results in a multi-stream PFHE used in liquefier in Claude cycle, and the numerical results were in good agreement with the experimental results. The effect of the axial conduction on heat transfer performance of PFHE was investigated, and it was observed that the effectiveness of PFHE considering axial conduction decreased by 21.8%, compared with that without considering axial conduction. Moreover, the influence of the adiabatic boundary condition on the cold and hot ends of separating plate of PFHE was transferred to the inner domain of PFHE by axial conduction effect, which resulted in the fluid temperature distortion in near-inlet domain. When the boundary conditions of constant wall temperature or constant heat flux were adopted on hot and cold ends of separating plate respectively, the fluid temperature distortion in near-inlet domain almost disappeared. When considering axial heat conduction, compared with the adiabatic boundary conditions at both ends of the partition, the effectiveness of the constant wall temperature boundary conditions increases by 35.8%( $ε c$ ) and 31.7%( $ε h$ ), and the effectiveness of the constant heat flow boundary conditions increases by 22.8%( $ε$ ).

Key words: thermal boundary condition, plate fin heat exchanger, axial conduction, cold end of separating plate, hot end of separating plate, effectiveness

摘要：

基于MATLAB编程，采用分布参数法构建了逆流板翅式换热器的二维计算模型，并与Claude循环氦液化器中多股流板翅式换热器的实验结果进行比较，数值结果和实验结果的吻合程度很好。研究了轴向导热对板翅式换热器换热能力的影响，发现考虑轴向导热的有效度相较于不考虑轴向导热降低了21.8%，且由于轴向导热将隔板冷端和热端的绝热边界条件施加的影响向换热器计算域内部传递，引发了换热器入口区域流体温度的畸变。而在隔板的冷端和热端分别采取定壁温或定热流的边界条件时，流体入口区域温度畸变几乎消失。在考虑轴向导热时，与隔板两端绝热边界条件相比，定壁温边界条件有效度增加35.8%（ $ε c$ ）和31.7%（ $ε h$ ），定热流边界条件有效度增加22.8%（ $ε$ ）。

关键词: 热边界条件, 板翅换热器, 轴向导热, 隔板冷端, 隔板热端, 有效度

CLC Number:

TK 124

LI Ke, WEN Jian, WANG Simin. Effect of axial heat conduction on heat transfer performance of plate fin heat exchanger under different thermal boundary condition[J]. CIESC Journal, 2021, 72(4): 1956-1964.

李科, 文键, 王斯民. 不同热边界条件下板翅式换热器轴向导热对换热的影响[J]. 化工学报, 2021, 72(4): 1956-1964.

Figures/Tables 8

Fig.1 Model of reverse-flow plate fin heat exchanger

Fig.2 Interaction effects between different nodes

Fig.3 Calculation process

Table 1 Comparison between experimental results and numerical results

制冷模式		液化模式
T_out,exp/K	T_out,num/K	T_out,exp/K	T_out,num/K
12.5	12.82	13.3	13.72
44.4	44.03	51.1	50.73
13.1	12.91	14.9	14.72

Table 2 Operation condition of reverse-flow plate fin heat exchanger

流体编号	工质	质量流量/(g/s)	入口温度/K	入口压力/MPa	总层数
1	N₂	1	80	0.11	1
2	N₂	1	311	0.11	1

Fig.4 Distribution of axial fluid temperature (adiabatic boundary condition)

Fig.5 Distribution of axial fluid temperature (constant wall temperature boundary condition)

Fig.6 Distribution of axial fluid temperature (constant heat flux boundary condition)

References 32

1	康蕊, 厉彦忠, 杨宇杰, 等. 轴向导热对板翅式换热器传热性能的影响[J]. 西安交通大学学报, 2017, 51(2): 140-148.
	Kang R, Li Y Z, Yang Y J, et al. Performance evaluation of plate-fin heat exchanger considering effect of axial heat conduction[J]. Journal of Xi'an Jiaotong University, 2017, 51(2): 140-148.
2	Kays W M, London A L. Heat-transfer and flow-friction characteristics of some compact heat-exchanger surfaces[J]. Test System and Procedure, 1950, 38(18): 1075-1085.
3	Yang H Z, Wen J, Wang S M, et al. Effect of fin types and Prandtl number on performance of plate-fin heat exchanger: experimental and numerical assessment[J]. Applied Thermal Engineering, 2018, 144: 726-735.
4	Shah R K, Sekuli D P. Fundamentals of Heat Exchanger Design[M]. Hoboken, NJ, USA:John Wiley & Sons, Inc., 2003.
5	文键, 李科, 刘育策, 等. 利用流固耦合分析的板翅式换热器锯齿型翅片多目标优化[J]. 西安交通大学学报, 2018, 52(2): 130-135.
	Wen J, Li K, Liu Y C, et al. Multi-objective optimization of serrated fin in plate-fin heat exchanger by fluid structure interaction[J]. Journal of Xi'an Jiaotong University, 2018, 52(2): 130-135.
6	Zhu Y H, Li Y Z. Three-dimensional numerical simulation on the laminar flow and heat transfer in four basic fins of plate-fin heat exchangers[J]. Journal of Heat Transfer, 2008, 130(11): 111801.
7	Yang Y J, Li Y Z, Si B, et al. Performance evaluation of heat transfer enhancement in plate-fin heat exchangers with offset strip fins[J]. Physics Procedia, 2015, 67: 543-550.
8	Pacio J C, Dorao C A. A review on heat exchanger thermal hydraulic models for cryogenic applications[J]. Cryogenics, 2011, 51(7): 366-379.
9	Li K, Wen J, Liu Y C, et al. Application of entransy theory on structure optimization of serrated fin in plate-fin heat exchanger[J]. Applied Thermal Engineering, 2020, 173: 114809.
10	André G M, Magande H L. Fundamentals of Heat Exchanger Design[M]. New Jersy, USA:John Wiley & Sons, Ltd., 2012:101-105.
11	Muller A. New charts for true mean temperature difference in heat exchangers [C] // 9th National Heat Transfer Conference. 1967:203-213.
12	Roetzel W, Spang B. Verbessertes Diagramm zur Berechnung von Wärmeubertragern[J]. Wärme - Und Stoffubertragung, 1990, 25(5): 259-264.
13	王松汉. 板翅式换热器[M]. 北京: 化学工业出版社, 1984: 103-106.
	Wang S H. Plate Fin Heat Exchanger [M]. Beijing: Chemical Industry Press, 1984: 103-106.
14	Chato J C, Laverman R J, Shah J M. Analyses of parallel flow, multi-stream heat exchangers[J]. International Journal of Heat and Mass Transfer, 1971, 14(10): 1691-1703.
15	Prasad B S V. Fin efficiency and mechanisms of heat exchange through fins in multi-stream plate-fin heat exchangers: development and application of a rating algorithm[J]. International Journal of Heat and Mass Transfer, 1997, 40(18): 4279-4288.
16	Prasad B S V. Fin efficiency and mechanisms of heat exchange through fins in multi-stream plate-fin heat exchangers: formulation[J]. International Journal of Heat and Mass Transfer, 1996, 39(2): 419-428.
17	李日新. 低温混合工质在板翅式换热器内的传热特性研究[D]. 广州: 华南理工大学, 2018.
	Li R X. Research on heat transfer characteristics of cryogenic mixed refrigerant inside plate fin heat exchanger[D]. Guangzhou: South China University of Technology, 2018.
18	Li R X, Liu J P, Liu J Y, et al. Measured and predicted upward flow boiling heat transfer coefficients for hydrocarbon mixtures inside a cryogenic plate fin heat exchanger[J]. International Journal of Heat and Mass Transfer, 2018, 123: 75-88.
19	李俊. 机载多股流板翅式换热器性能研究[D]. 南京: 南京航空航天大学, 2015.
	Li J. Study on performance of airborne multi-stream plate-fin heat exchanger[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2015.
20	李俊, 蒋彦龙, 周年勇, 等. 交叉式多股流板翅式换热器数值研究[J]. 航空动力学报, 2016, 31(5): 1087-1096.
	Li J, Jiang Y L, Zhou N Y, et al. Numerical study on cross-type multi-stream plate-fin heat exchanger[J]. Journal of Aerospace Power, 2016, 31(5): 1087-1096.
21	李俊, 蒋彦龙, 王瑜, 等. 机载三股流板翅式冷凝器数值计算与实验研究[J]. 南京航空航天大学学报, 2017, 49(3): 382-388.
	Li J, Jiang Y L, Wang Y, et al. Numerical calculation and experimental investigation on airborne three-stream plate-fin condenser[J]. Journal of Nanjing University of Aeronautics & Astronautics, 2017, 49(3): 382-388.
22	Krishna V, Spoorthi S, Hegde P G, et al. Effect of longitudinal wall conduction on the performance of a three-fluid cryogenic heat exchanger with three thermal communications[J]. International Journal of Heat and Mass Transfer, 2013, 62: 567-577.
23	Ranganayakulu C, Seetharamu K N, Sreevatsan K V. The effects of longitudinal heat conduction in compact plate-fin and tube-fin heat exchangers using a finite element method[J]. International Journal of Heat and Mass Transfer, 1997, 40(6): 1261-1277.
24	Yuan P, Kou H S. The comparison of longitudinal wall conduction effect on the crossflow heat exchangers including three fluid streams with different arrangements[J]. Applied Thermal Engineering, 2001, 21(18): 1891-1907.
25	Gupta P, Atrey M D. Performance evaluation of counter flow heat exchangers considering the effect of heat in leak and longitudinal conduction for low-temperature applications[J]. Cryogenics, 2000, 40(7): 469-474.
26	Nellis G F. A heat exchanger model that includes axial conduction, parasitic heat loads, and property variations[J]. Cryogenics, 2003, 43(9): 523-538.
27	Maranzana G, Perry I, Maillet D. Mini- and micro-channels: influence of axial conduction in the walls[J]. International Journal of Heat and Mass Transfer, 2004, 47(17/18): 3993-4004.
28	甘云华, 杨泽亮. 轴向导热对微通道内传热特性的影响[J]. 化工学报, 2008, 59(10): 2436-2441.
	Gan Y H, Yang Z L. Effect of axial heat conduction on heat transfer in micro-channels[J]. Journal of Chemical Industry and Engineering (China), 2008, 59(10): 2436-2441.
29	Pradeep Narayanan S, Venkatarathnam G. Performance of a counterflow heat exchanger with heat loss through the wall at the cold end[J]. Cryogenics, 1999, 39(1): 43-52.
30	陶文铨. 数值传热学[M]. 2版. 西安: 西安交通大学出版社, 2001.
	Tao W Q. Numerical Heat Transfer[M]. 2nd ed. Xi'an: Xi'an Jiaotong University Press, 2001.
31	Manglik R M, Bergles A E. Heat transfer and pressure drop correlations for the rectangular offset strip fin compact heat exchanger[J]. Experimental Thermal and Fluid Science, 1995, 10(2): 171-180.
32	Goyal M, Kumar J, Chakravarty A, et al. In-field performance evaluation of a large size multistream plate fin heat exchanger installed in a helium liquefier[J]. Heat Transfer Engineering, 2020, 41(1): 101-112.

[1]	Jipeng ZHOU, Wenjun HE, Tao LI. Reaction engineering calculation of deactivation kinetics for ethylene catalytic oxidation over irregular-shaped catalysts [J]. CIESC Journal, 2023, 74(6): 2416-2426.
[2]	Haiyan ZHANG, Jiangfeng GUO, Xiulan HUAI, Xinying CUI. Investigations of axial conduction effect on local heat transfer performance in PCHE [J]. CIESC Journal, 2019, 70(12): 4590-4598.
[3]	ZHOU Jipeng, FANG Dingye, LI Tao. Reaction engineering calculation for ethylene catalytic oxidation over gear-shaped catalysts [J]. CIESC Journal, 2016, 67(7): 2808-2814.
[4]	QIN Wen, ZHOU Zhiming, CHENG Zhenmin. Influence of catalyst shape on methane steam reforming and simulation of industrial reactor [J]. CIESC Journal, 2016, 67(2): 563-572.
[5]	ZHANG Shuang, MA Guoyuan, ZHANG Sichao, ZHOU Feng. Heat transfer performance test and analysis of thermosyphon heat exchanger [J]. CIESC Journal, 2014, 65(z2): 83-87.
[6]	XIE Yingchun, MEI Ning. Energy effectiveness analysis of countercurrent humidifier [J]. CIESC Journal, 2014, 65(S1): 61-65.
[7]	LI Yan, LI Yuxing, HU Qihui, WANG Wuchang, XIE Bin, YU Xichong. Sensitivity analysis for performance of a new gas-liquid distributor used in plate fin heat exchangers [J]. CIESC Journal, 2013, 64(6): 2007-2014.
[8]	FANG Yuanxiang, GOVIND Rakesh. A New Thiele's Modulus for the Monod Biofilm Model [J]. , 2008, 16(2): 277-286.
[9]	JIANG Yuanli, LIM Mee Sook, KIM Dong Hyun. Simulation Studies of the Hydrogen Production from Methanol Partial Oxidation Steam Reforming by a Tubular Packed-bed Catalytic Reactor [J]. , 2001, 9(3): 297-305.
[10]	WU Yanxiang, WANG Liangen. A New Procedure to Solve the Non-Linear Reaction-Diffusion Equation [J]. , 2000, 8(1): 92-94.
[11]	YIN Qiuxiang, LI Shaofen. Estimation of overall effectiveness factors for parallel catalytic reactions [J]. , 1997, 5(2): 147-158.