顾昕¹,文键¹,张星¹,王斯民²,厉彦忠¹

• 1:西安交通大学 能源与动力工程学院， 陕西 西安 710049
• 2:西安交通大学 化学工程与技术学院， 陕西 西安 710049

摘要(Abstract)：

为了解新型环保工质R1234ze（E）微小通道内的冷凝换热及阻力特性，提出采用VOF（volume of fluid）模型对R1234ze（E）和R134a（T_sat=40℃）在水平微细圆管（D_h=1 mm）内的冷凝过程进行数值模拟研究，探讨质量流量、干度以及物性对管内冷凝换热和阻力性能的影响。结果表明，R1234ze（E）和R134a的换热系数和压降都随质量流速和干度的增大而增大。相同情况下，R1234ze（E）换热系数小于R134a，但压降大于R134a。R1234ze（E）的液膜厚度平均要比R134a薄15.7%。当气液两相都为湍流，有效热导率对不同工质在水平圆管内的冷凝换热性能有重要影响。R1234ze（E）在管内的液膜分布特性整体上和R134a相似。现有的关联式对R1234ze（E）的压降都存在一定的低估，平均绝对误差都在30%左右。

关键词(KeyWords)： 微细通道;冷凝;R1234ze(E);换热系数;压降梯度

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金（51676146）。

作者(Author): 顾昕¹,文键¹,张星¹,王斯民²,厉彦忠¹

DOI: 10.3969/j.issn.1003-9015.2020.01.012

参考文献(References)：

• [1] CAVALLINI A, DORETTI L, MATKOVIC M, et al. Update on condensation heat transfer and pressure drop inside minichannels[J]. Heat Transfer and Engineering, 2006, 27(4):74-87.
  [2] AWAD M M, DALKILIC A S, WONGWISES S. A critical review on condensation heat transfer in microchannels and minichannels[J]. Journal of Nanoscience and Nanotechnology, 2014, 5(1):1-25.
  [3] MOTA-BABILONI A, NAVARRO-ESBRÍ J, MOLÉS F, et al. A review of refrigerant R1234ze(E) recent investigations[J]. Applied Thermal Engineering, 2016, 95(1):211-222.
  [4] WANG J, LI J M, HWANG Y. Flow pattern transition during condensation of R134a and R1234ze(E) in microchannel arrays[J]. Applied Thermal Engineering, 2017, 115(1):244-255.
  [5] LIU N, XIAO H, LI J M. Experimental investigation of condensation heat transfer and pressure drop of propane, R1234ze(E) and R22 in minichannels[J]. Applied Thermal Engineering, 2016, 102(1):63-72.
  [6] JIGE D, INOUE N, KOYAMA S. Condensation of refrigerant in a multiport tube with rectangular minichannels[J]. International Journal of Refrigeration, 2016, 67(1):202-213.
  [7] DEL COL D, BORTOLATO M, AZZOLIN M, et al. Condensation heat transfer and two-phase frictional pressure drop in a single minichannel with R1234ze(E) and other refrigerants[J]. International Journal of Refrigeration, 2015, 50(1):87-103.
  [8] HOSSAIN M A, ONAKA Y, MIYARA A. Experimental study on condensation heat transfer and pressure drop in horizontal smooth tube for R1234ze(E), R32 and R410A[J]. International Journal of Refrigeration, 2012, 35(1):927-938.
  [9] NEMA G, GARIMELLA S, FRONK B M. Flow regime transitions during condensation in microchannels[J]. International Journal of Refrigeration, 2014, 40(1):227-240.
  [10] BRACKBILL J U, KOTHE D B, ZEMACH C. A continuum method for modeling surface tension[J]. Journal of Computational Physics, 1992, 100(2):335-354.
  [11] DA RIVA E, DEL COL D, GARIMELLA S V, et al. The importance of turbulence during condensation in a horizontal circular minichannel[J]. International Journal of Heat and Mass Transfer, 2012, 55(1):3470-3481.
  [12] LEE W H. A pressure iteration scheme for two-phase flow modeling[M]. Washington:Hemisphere press, 1980.
  [13] DA RIVA E, DEL COL D. Numerical simulation of laminar liquid film condensation in a horizontal circular minichannel[J]. Journal of Heat Transfer, 2012, 134(5):1-8.
  [14] SHAH M M. An improved and extended general correlation for heat transfer during condensation in plain tubes[J]. HVAC&R Research, 2009, 15(5):889-913.
  [15] THOME J R, HAJAL J E, CAVALLINI A. Condensation in horizontal tubes, part 2:New heat transfer model based on flow regimes[J]. International Journal of Heat and Mass Transfer, 2003, 46(1):3365-3387.
  [16] CAVALLINI A, DEL COL D, DORETTI L, et al. Condensation in horizontal smooth tubes:a new heat transfer model for heat exchanger design[J]. Heat Transfer and Engineering, 2006, 27(8):31-38.
  [17] DOBSON M K, CHATO J C. Condensation in smooth horizontal tubes[J]. Journal of Heat Transfer, 1998, 120(1):193-213.
  [18] FRIEDEL L. Improved friction pressure drop correlations for horizontal and vertical two-phase pipe flow[C]. Process of European Two-phase Flow Group Meet. Ispra:Paper E, 1979.
  [19] KIM S M, MUDAWAR I. Universal approach to predicting two-phase frictional pressure drop for adiabatic and condensing mini/micro-channel flows[J]. International Journal of Heat and Mass Transfer, 2012, 55(1):3246-3261.
  [20] SUN L, MISHIMA K. Evaluation analysis of prediction methods for two-phase flow pressure drop in mini-channels[J]. International Journal of Multiphase Flow, 2009, 35(1):47-54.
  [21] ZHANG M, WEBB R L. Correlation of two-phase friction for refrigerants in small-diameter tubes[J]. Experimental Thermal and Fluid Science, 2001, 25(3/4):131-139.