Overall heat transfer coefficient of plate-fin heat exchanger during a mixed refrigerant cryogenic process in low quality

doi:10.11949/j.issn.0438-1157.20151177

Abstract

Abstract:

Plate-fin heat exchangers (PFHEs) are mostly employed in medium- and small-sized LNG plants. However, works about the heat transfer characteristic optimization of mixed refrigerant in PFHE under low quality have been barely carried out nowadays. Thus, a Linde-Hampson cycle using single stage compressors and recuperative heat exchanger was established and mixed refrigerant (N₂-CH₄-C₂H₄-C₃H₈-iC₄H₁₀) was used to obtain the refrigeration temperature of -160℃. Meanwhile, the overall heat transfer coefficient and the correlational influence factor were mainly analysed. The experimental results showed that the overall heat transfer coefficient of the PFHE was about 2.6—22.7 W·m^-2·K^-1 while the refrigeration temperature and the circulated composition had week influence on the overall heat transfer coefficient. Meanwhile, the existing correlations cannot accurately predict the heat transfer coefficient of the mixed refrigerant under low quality and low flow velocity. However, the correlation of Cavallini and modified Granryd can used to predict the HTC of mixed refrigerant under low quality and low flow velocity after modification in this work. Additionally, some suggestion have been proposed in the design and optimization of PFHEs considering the refrigerate flowrate and pressure drop.

Key words: natural gas, liquefaction, mixed refrigerant, plate-fin heat exchanger, cryogenic, heat transfer, heat transfer coefficient, pressure drop

摘要：

对于中小型天然气液化装置,板翅式换热器被广泛应用于回热换热。然而,目前对低干度混合工质在板翅式换热器中低温换热性能优化等问题的研究甚少。因此,搭建一套采用单级压缩、一级回热的Linde-Hampson制冷循环系统,并以N₂-CH₄-C₂H₄-C₃H₈-iC₄H₁₀作为混合制冷剂制取-160℃低温,用以重点分析板翅式换热器中的总传热系数以及影响板翅式换热器传热系数的因素。实验结果表明:低干度下板翅式换热器中总传热系数在2.6~22.7 W·m^-2·K^-1之间,受制冷温度和循环浓度变化的影响不明显,而目前对低干度低流速下混合制冷剂的低温换热性能预测仍存在一定的偏差,其中Cavallini和Modified Granryd的计算模型经修正后可推荐使用;同时,也从制冷剂流速、压降等方面对板翅式换热器优化设计提出了相关建议。

关键词: 天然气, 液化, 混合工质, 板翅式换热器, 低温制冷, 传热, 传热系数, 压降

CLC Number:

TB61⁺1

CAO Le, LIU Jinping, XU Xiongwen, LI Rixin. Overall heat transfer coefficient of plate-fin heat exchanger during a mixed refrigerant cryogenic process in low quality[J]. CIESC Journal, 2016, 67(4): 1277-1286.

曹乐, 刘金平, 许雄文, 李日新. 用于低干度混合工质制冷的板翅式换热器传热系数[J]. 化工学报, 2016, 67(4): 1277-1286.

References 25

[1]	陈长青. 多股流板翅式换热器的传热计算[J]. 制冷学报, 1982, (1): 30-41. CHEN C Q. Heat transfer calculation for multifluid plate-fin heat exchangers[J]. Journal of Refrigeration, 1982, (1): 30-41.
[2]	崔国民, 卢洪波, 蔡祖恢, 等. 场协同下的多股流换热器换热性能的研究[J]. 工程热物理学报, 2002, 23(3): 323-326. DOI: 10.3321/j.issn:0253-231X.2002.03.017. CUI G M, LU H B, CAI Z H, et al. Study on the heat-transfer property of multi-stream heat exchangers under the effect of field-synergism[J]. Journal of Engineering Thermophysics, 2002, 23(3): 323-326. DOI: 10.3321/j.issn:0253-231X.2002.03.017.
[3]	MULLER-MENZEL T, HECHT T. Plate-fin heat exchanger performance reduction in special two-phase flow conditions[J]. Cryogenics, 1995, 35(5): 297-301. DOI: 10.1016/0011-2275(95)95347-H.
[4]	董军启, 陈江平, 陈芝久. 锯齿翅片的传热与阻力性能试验[J]. 化工学报, 2007, 58(2): 281-285. DONG J Q, CHEN J P, CHEN Z J. Test of flow and heat transfer characteristics for offset strip fin[J]. Journal of Chemical Industry and Engineering (China), 2007, 58(2): 281-285.
[5]	焦安军, 厉彦忠, 张瑞, 等. 板翅式换热器导流片结构参数对其导流性能的影响[J]. 化工学报, 2003, 54(2): 153-158. JIAO A J, LI Y Z, ZHANG R, et al. Effects of different distributor configuration parameters on fluid flow distribution in plate-fin heat exchanger[J]. Journal of Chemical Industry and Engineering (China), 2003, 54(2): 153-158.
[6]	李淑英, 王忠建, 张杨. 多股流换热器的通道分配设计方法[J]. 流体机械, 2011, 39(11): 37-40. DOI: 10.3969/j.issn.1005-0329. 2011.011.009. LI S Y, WANG Z J, ZHANG Y. Passage arrangement and parameter match in multi-stream heat exchanger[J]. Fluid Machinery, 2011, 39(11): 45-49. DOI: 10.3969/j.issn.1005-0329.2011.011.009.
[7]	王伟平. 大型冷箱内换热器及其配管系统的流体均配与传热优化研究[D]. 杭州: 浙江大学, 2014. WANG W P. Study on flow distribution characteristics and heat transfer optimization for the heat exchangers and its manifold system in large-scale cold box[D]. Hangzhou: Zhejiang University, 2014.
[8]	TIAN Q, HE G, ZHAO L, et al. Passage arrangement optimization of multi-stream plate-fin heat exchangers[J]. Applied Thermal Engineering, 2014, 73(1): 963-974. DOI: 10.1016/j.applthermaleng. 2014.08.055.
[9]	彭波涛, 罗来勤, 王秋旺, 等. 多股流板翅式换热器的微分与优化数值研究[J]. 化工学报, 2004, 55(6): 876-881. PENG B T, LUO L Q, WANG Q W, et al. Numerical study of differential and optimal design for multi-stream plate-fin heat exchanger[J]. Journal of Chemical Industry and Engineering (China), 2004, 55(6): 876-881.
[10]	张哲, 厉彦忠, 田津津. 多股流板翅式换热器的优化设计[J]. 石油化工, 2002, 31(11): 928-931. DOI: 10.3321/j.issn:1000-8144. 2002.11.016. ZHANG Z, LI Y Z, TIAN J J. Optimum design of multistream palte-fin heat exchanger[J]. Petrochemical Technology, 2002, 31(11): 928-931. DOI: 10.3321/j.issn:1000-8144.2002.11.016.
[11]	YOUSEFI M, ENAYATIFAR R, DARUS A N, et al. Optimization of plate-fin heat exchangers by an improved harmony search algorithm[J]. Applied Thermal Engineering, 2013, 50(1): 877-885. DOI: 10.1016/j.applthermaleng.2012.05.038.
[12]	YANG Y, LI Y. General prediction of the thermal hydraulic performance for plate-fin heat exchanger with offset strip fins[J]. International Journal of Heat and Mass Transfer, 2014, 78: 860-870. DOI: 10.1016/j.ijheatmasstransfer.2014.07.060.
[13]	鲁凯, 鹿来运, 张镨, 等. 预冷式混合工质循环天然气液化系统实验及组分影响分析[J]. 低温工程, 2010, (4): 37-41. DOI: 10.3969/j.issn.1000-6516.2010.04.009. LU K, LU L Y, ZHANG P, et al. Experiment and composition analysis of pre-cooling mixed-refrigerant-cycle gas liquefaction system[J]. Cryogenics, 2010, (4): 37-41. DOI: 10.3969/j.issn.1000-6516. 2010.04.009.
[14]	张镨, 鹿来运, 郭开华. 低温混合工质循环多股流换热器性能分析[J]. 低温工程, 2012, 189(5): 46-50. DOI: 10.3969/j.issn. 1000-6516. 2012.05.011. ZHANG P, LU L Y, GUO K H. Performance analysis of multi-stream heat exchanger in low temperature mixed-refrigerant-cycle[J]. Cryogenics, 2012, 189(5): 46-50. DOI: 10.3969/j.issn. 1000-6516. 2012.05.011.
[15]	KHOSHVAGHT-ALIABADI M, HORMOZI F, ZAMZAMIAN A. Role of channel shape on performance of plate-fin heat exchangers: experimental assessment[J]. International Journal of Thermal Sciences, 2014, 79: 183-193. DOI: 10.1016/j.ijthermalsci. 2014.01.004.
[16]	NAGARAJAN V, CHEN Y, WANG Q, et al. Hydraulic and thermal performances of a novel configuration of high temperature ceramic plate-fin heat exchanger[J]. Applied Energy, 2014, 113: 589-602. DOI: 10.1016/j.ijthermalsci.2014.01.004.
[17]	广汇能源股份有限公司. 2015年6月广汇能源市场及项目简报[R]. 乌鲁木齐: 广汇能源, 2015. Guanghui Energy Co., Ltd. Brief report of market and project by Guanghui Energy in June 2015[R]. Urumchi: Guanghui, 2015.
[18]	ARDHAPURKAR P M, SRIDHARAN A, ATREY M D. Experimental investigation on temperature profile and pressure drop in two-phase heat exchanger for mixed refrigerant Joule-Thomson cryocooler[J]. Applied Thermal Engineering, 2014, 66(1/2): 94-103. DOI: 10.1016/j.applthermaleng.2014.01.067.
[19]	ARDHAPURKAR P M, SRIDHARAN A, ATREY M D. Performance evaluation of heat exchanger for mixed refrigerant J-T cryocooler[J]. Cryogenics, 2014, 63: 49-56. DOI: 10.1016/j.cryogenics.2014.06.012.
[20]	KRAUS A D, AZIZI A, WELTY J. Extended Surface Heat Transfer[M]. Hoboken: John Wiley & Sons, 2007: 456.
[21]	SUNDEN B. Kirk-Othmer Encyclopedia of Chemical Technology[M]. Hoboken: John Wiley & Sons, 2007: 4.
[22]	LITTLE W A. Heat transfer efficiency of Kleemenko cycle heat exchangers[C]//Weisend J G. Advances in Cryogenic Engineering, Transactions of the Cryogenic Engineering Conference-CEC. U.S.:AIP Proceeding Chattanooga (Tennessee), 2007: 606-613.
[23]	KEDZIERSKI M A, DIDION D A. Visualization of nucleate flow boiling for an R22/R114 mixture and its components[J]. Experimental Heat Transfer, 1990, 3(4): 447-463. DOI: 10.1080/08916159008946401.
[24]	BAEK S, JEONG S, HWANG G. Pressure drop characteristics of cryogenic mixed refrigerant at macro and micro channel heat exchangers[J]. Cryogenics, 2013, 52(12): 689-694. DOI: 10.1016/j.cryogenics.2012.06.012.
[25]	BELL I H, GROLL E A. Air-side particulate fouling of microchannel heat exchangers: experimental comparison of air-side pressure drop and heat transfer with plate-fin heat exchanger[J]. Applied Thermal Engineering, 2011, 31(5): 742-749. DOI: 10.1016/j.applthermaleng. 2010.10.019.