孔板结构换热器传热与阻力性能的数值模拟

doi:10.11949/j.issn.0438-1157.20170744

摘要/Abstract

摘要：

基于周期性全截面模型及RNG k-ε湍流模型，运用计算流体力学软件FLUENT对不同孔板结构换热器壳程流体流动以及传热性能进行了数值模拟分析，并通过文献试验数据验证了该数值模拟方法的可行性和准确性。在此基础上，对比分析了三叶孔、四叶孔、五叶孔、大圆孔、小圆孔等5种孔板结构的传热与阻力性能，探讨了支撑板等结构参数对其传热与阻力性能的影响，进一步采用场协同原理探讨了孔板换热器的强化传热机理。研究结果表明：采用RNG k-ε湍流模型以及周期性全截面模型可较为准确地模拟孔板换热器壳程流体流动情况；5种模型中五叶孔换热器的传热特性最好但阻力最大，小圆孔的传热效果最差但阻力最小；随着支撑板间距以及开孔高度的增加，换热器壳程的传热系数和压力降均逐渐降低；在支撑板后，速度矢量与温度梯度之间的夹角波动幅度变化剧烈，起到了强化壳程传热的效果；其中五叶孔板的场协同角波动幅度最大，强化传热效果最好。

关键词: 孔板结构, 周期性, 传热, 计算流体力学, 数值模拟

Abstract:

Based on simplified periodic model and RNG k-ε turbulence model, the flow characteristics and heat transfer properties of shell-side fluid in perforated-baffle heat exchangers were numerically simulated by using CFD software FLUENT. The feasibility and accuracy of numerical simulation method was verified by experiment. The heat transfer and resistance performance of trefoil-baffle, four-leaf-hole baffle, five-leaf-hole baffle, big-hole baffle and small-hole baffle are analyzed. Then the influences of structural parameters on heat transfer and resistance performance were discussed. Furthermore, heat transfer enhancement mechanism of perforated-baffle structure heat exchangers was investigated based on the field synergy principle. The results showed that the fluid flow in the shell-side of the perforated-baffle structure heat exchanger can be accurately simulated by using the RNG k-ε turbulence model and the simplified periodic model. The heat transfer coefficient of five-leaf-hole baffle is the best while the resistance the greatest. The heat transfer coefficient of the small-hole baffle is the worst, while the resistance is the least. The heat transfer coefficient and pressure drop decrease when baffle pitch and hole-height increase. Behind the support plate, the angle between the velocity vector and the temperature gradient varies violently, which enhances the heat transfer in the shell-side. The field synergy angle of five-leaf-hole baffle has the largest fluctuation range, and the enhancement of heat transfer effect is the best.

Key words: perforated-baffle structure, periodicity, heat transfer, computational fluid dynamics, numerical simulation

中图分类号:

TK124

侯夏玲, 周帼彦, 涂善东. 孔板结构换热器传热与阻力性能的数值模拟[J]. 化工学报, 2017, 68(12): 4517-4525.

HOU Xialing, ZHOU Guoyan, TU Shandong. Numerical study on heat transfer and resistance performance of heat exchangers with perforated-baffle structure[J]. CIESC Journal, 2017, 68(12): 4517-4525.

参考文献 30

[1]	方书起, 祝春进, 吴勇, 等. 强化传热技术与新型高效换热器研究进展[J]. 化工机械, 2004, 31(4):249-253. FANG S Q, ZHU C J, WU Y, et al. Research progress of strengthened heat transfer technique and new type high efficient heat exchangers[J]. Chemical Engineering & Machinery, 2004, 31(4):249-253.
[2]	钱才富, 高宏宇, 孙海阳. 曲面弓形折流板换热器壳程流体流动与传热[J]. 化工学报, 2011, 62(5):1233-1238. QIAN C F, GAO H Y, SUN H Y. Shell-side fluid flow and heat transfer in curved baffle heat exchanger[J]. CIESC Journal, 2011, 62(5):1233-1238.
[3]	杜文静, 王红福, 程林. 螺旋折流板换热器壳程流动特性[J]. 化工学报, 2014, 65(8):2970-2975. DU W J, WANG H F, CHENG L. Shell side fluid flow characteristics in helical baffled heat exchanger[J]. CIESC Journal, 2014, 65(8):2970-2975.
[4]	董其伍, 杜庆飞, 刘敏珊, 等. 三叶孔板换热器壳程流体流动和传热特性数值研究[J]. 化工设备与管道, 2012, 49(2):21-23. DONG Q W, DU Q F, LIU M S, et al. Numerical research on flow and heat transfer characteristics in shell-side of heat exchanger with trefoil-tube-support[J]. Process Equipment & Piping, 2012, 49(2):21-23.
[5]	BUTTERWORTH D. A model for heat transfer during three-dimensional flow in tube bundles[C]//6th International Heat Transfer Conference. Toronto, 1978:219-224.
[6]	姚璃, 韩东, 罗朝嘉, 等. 梅花形孔板换热器壳程流动与换热特性模拟[J]. 能源化工, 2017, 38(1):85-90. YAO L, HAN D, LUO C J, et al. Numerical simulation on shell-side flow and heat transfer of cinquefoil orifice baffle heat exchanger[J]. Energy Chemical Industry, 2017, 38(1):85-90.
[7]	GREEN S J. Thermal hydraulic and corrosion aspects of PWR steam generator problems[J]. Heat Transfer Engineering, 1988, 9(1):19-22.
[8]	WANG Y S, LIU Z C, HUANG S Y, et al. Experimental investigation of shell-and-tube heat exchanger with a new type of baffles[J]. Heat & Mass Transfer, 2011, 47(7):833-839.
[9]	李雅侠, 娄岩, 战洪仁, 等. 梅花孔板纵向流换热器壳程流动与传热的三维数值模拟[J]. 过程工程学报, 2015, 15(4):639-645. LI Y X, LOU Y, ZHAN H R, et al.. Three-dimensional numerical simulation of fluid flow and heat transfer in the shell side of quincunx orifice baffle longitudinal flow type heat exchanger[J]. The Chinese Journal of Process Engineering, 2015, 15(4):639-645.
[10]	罗朝嘉, 韩东, 牟春燕, 等. 孔板结构对梅花形孔板换热器壳程传热影响的模拟研究[J]. 能源化工, 2016, 37(1):55-59. LUO C J, HAN D, MOU C Y, et al. Numerical simulation study on the effects of orifice structure on the shell-side heat transfer of cinquefoil orifice baffle heat exchanger[J]. Energy Chemical Industry, 2016, 37(1):55-59.
[11]	朱凌云, 周帼彦, 朱冬生. 纵流壳程换热器传热性能研究进展[J]. 化工机械, 2014, 41(3):269-272. ZHU L Y, ZHOU G Y, ZHU D S. Progress in investigating heat transfer property of heat exchangers with longitudinal flow in shell side[J]. Chemical Engineering & Machinery, 2014, 41(3):269-272.
[12]	孙海阳. 大小孔折流板换热器壳程场协同分析[J]. 机械工程与自动化, 2014, (4):40-41. SUN H Y. Field synergy analysis LASH baffle heat exchanger in shell-side[J]. Mechanical Engineering & Automation, 2014, (4):40-41.
[13]	EL MAAKOUL A, LAKNIZI A, SAADEDDINE S, et al. Numerical comparison of shell-side performance for shell and tube heat exchangers with trefoil-hole, helical and segmental baffles[J]. Applied Thermal Engineering, 2016, 109:175-185.
[14]	PATANKAR S V, SPALDING D B. A calculation procedure for the transient and steady state behavior of shell-and-tube heat exchanger[M]//AFGAN A A, SCHLUNDER E U. Heat Exchanger:Design and Theory Source Book. Washington:McGraw-Hill, 1974.
[15]	PRITHIVIRAJ M, ANDREWS M J. Three-dimensional numerical simulation of shell-and-tube heat exchangers(Ⅰ):Foundation and fluid mechanics[J]. Numerical Heat Transfer, Part A:Applications, 1998, 33(8):799-816.
[16]	PRITHIVIRAJ M, ANDREWS M J. Three-dimensional numerical simulation of shell-and-tube heat exchangers(Ⅱ):Heat transfer[J]. Numerical Heat Transfer, Part A:Applications, 1988, 33(8):817-828.
[17]	PRITHIVIRAJ M, ANDREWS M J. Comparison of a three-dimensional numerical model with existing methods for prediction of flow in shell-and-tube heat exchangers[J]. Heat Transfer Engineering, 1999, 20(2):15-19.
[18]	曾文良, 张复兴, 王剑秋, 等. 轴流管壳式换热器壳侧流体优化分布数值研究[J]. 衡阳师范学院学报, 2009, 30(3):65-69. ZENG W L, ZHANG F X, WANG J Q, et al. Numerical investigation of fluid maldistribution of shell-side of shell-and-tube heat exchanger with longitudinal flow[J]. Journal of Hengyang Normal University, 2009, 30(3):65-69.
[19]	董其伍, 白彩鹏, 刘敏珊, 等. 三叶孔板换热器壳程流体流动和传热研究[J]. 工程热物理学报, 2013, 34(1):115-117. DONG Q W, BAI C P, LIU M S, et al. Research on flow and heat transfer in shell-side of the trefoil-baffle support type heat exchanger[J]. Journal of Engineering Thermophysics, 2013, 34(1):115-117.
[20]	DONG Q W, WANG Y Q, LIU M S. Numerical and experimental investigation of shell side characteristics for ROD baffle heat exchanger[J]. Applied Thermal Engineering, 2008, 28(7):651-660.
[21]	YOU Y H, CHEN Y Q, XIE M Q, et al. Numerical simulation and performance improvement for a small size shell-and-tube heat exchanger with trefoil-hole baffles[J]. Applied Thermal Engineering, 2015, 89(5):220-228.
[22]	YOU Y H, FAN A W, LAI X J, et al. Experimental and numerical investigations of shell-side thermo-hydraulic performances for shell-and-tube heat exchanger with trefoil-hole baffles[J]. Applied Thermal Engineering, 2013, 50(1):950-956.
[23]	周帼彦, 史燕华, 郭震, 等. 基于单元流道模型的三叶孔板换热器热力性能研究[J]. 压力容器, 2016, 33(4):10-17. ZHOU G Y, SHI Y H, GUO Z, et al. A study on the thermal performance of heat exchanger with trefoil-baffles by using unit duct model[J]. Pressure Vessel Technology, 2016, 33(4):10-17.
[24]	WANG D, WANG K, WANG Y Q, et al. Numerical and experimental investigation of the shell side characteristics of the trefoil-hole baffle heat exchanger[J]. Heat Transfer Research, 2017, 48(1):81-95.
[25]	魏志国, 李华峰, 柯汉兵, 等. 三叶孔板强化换热性能及机理分析[J]. 化工进展, 2017, 36(2):465-472. WEI Z G, LI H F, KE H B, et al. Analysis on performance and mechanism of heat transfer enhancement of trefoil-hole baffle[J]. Chemical Industry and Engineering Progress, 2017, 36(2):465-472.
[26]	董其伍, 杜庆飞, 刘敏珊, 等. 三叶孔板换热器壳程流体流动和传热特性数值研究[J]. 化工设备与管道, 2012, 49(2):21-23. DONG Q W, DU Q F, LIU M S, et al. Numerical research on flow and heat transfer characteristics in shell-side of heat exchanger with trefoil-tube-support[J]. Process Equipment & Piping, 2012, 49(2):21-23.
[27]	朱凌云, 郎红方, 周帼彦, 等. 三叶孔板换热器壳程流动及传热数值模拟[J]. 化工学报, 2014, 65(3):829-835. ZHU L Y, LANG H F, ZHOU G Y, et al. Numerical simulation on shell side fluid flow and heat transfer in heat exchanger with trefoil-baffles[J]. CIESC Journal, 2014, 65(3):829-835.
[28]	朱凌云, 杨锦春, 周帼彦, 等. 三叶孔板换热器热力性能及其影响因素分析[J]. 化工进展, 2014, 33(12):3183-3188. ZHU L Y, YANG J C, ZHOU G Y, et al. Investigation of the thermal performance of heat exchangers with trefoil-baffles[J]. Chemical Industry and Engineering Progress, 2014, 33(12):3183-3188.
[29]	郭震. 三叶孔板换热器壳程传热与阻力性能的试验研究[D]. 上海:华东理工大学, 2014. GUO Z. Experimental investigation of the shell-side heat transfer and friction characteristics of shell-and-tube heat exchangers with trefoil-hole baffles[D]. Shanghai:East China University of Science and Technology, 2014.
[30]	过增元. 换热器中的场协同原则及其应用[J]. 机械工程学报, 2003, 39(12):1-9 GUO Z Y. Principle of field coordination in heat exchangers and its application[J]. Chinese Journal of Mechanical Engineering, 2003, 39(12):1-9.