scholarly journals Structural parameters study on stainless-steel flat-tube heat exchangers with corrugated fins

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2743-2756
Author(s):  
Guifeng Gao ◽  
Fei Wang ◽  
Yongzhang Cui

A stainless steel corrugated fins and flat-tube heat exchanger is designed, which has a plate-fin structure. To optimize the structural parameters of this exchanger, including corrugation angle, corrugation pitch and fin length, 3-D simulation model and test were proposed. The numerical results indicated that the corrugation angle significantly affects both on heat transfer performance and pressure drop. The fin with angle, A = 0~20?, have demonstrated the higher heat transfer efficiency, lesser gas condensation, lower pressure drop, higher outlet flue gas temperature in low T region, and no exceeding the distortion temperature in high T region. Corrugation pitch and fin length influence thermal and hydraulic characteristics, outlet flue gas temperature, and fin temperature. To improve heat transfer performance, and reduce the fin temperature in high T region and ease gas condensation in low T region, smaller corrugation pitch and shorter fin length were recommended in the low T region, whereas higher values were more reasonable in high T region. Noticeably, the heat transfer and flow characteristics were better in the high T region than the low T region. Therefore, higher priority should be given to the structural optimization in the high T region in order to in-crease the heat transfer enhancement

2014 ◽  
Vol 1081 ◽  
pp. 270-274
Author(s):  
Zui Xian Yu ◽  
Xue Sheng Wang ◽  
Qin Zhu Chen

A new preparation technique of carbon steel/stainless steel clad tube was introduced, and the contact surface was well combined. Meanwhile, with the using of tube heat exchanger, the experiment on the heat transfer performance of the clad tube was done. Comparing the 10/316 clad tube and the 316 stainless steel tube, the effects on the heat transfer performance of 316 stainless steel tube attached to carbon steel was evaluated. It is showed that overall heat transfer coefficient of 10/316 clad tubes is higher than that of stainless steel tube. The average heat transfer coefficient of 10/316 clad tubes is about 18.7%~34.4% higher than that of stainless steel tube. Experimental investigation indicates that, by brazing and cold drawing, the 10/316 clad tube was well combined and the thermal conductivity was better than that of stainless steel tube.


2019 ◽  
Vol 33 (5) ◽  
pp. 419-439 ◽  
Author(s):  
Xu Peng ◽  
Dingbiao Wang ◽  
Guanghui Wang ◽  
Yushen Yang ◽  
Sa Xiang

2013 ◽  
Vol 423-426 ◽  
pp. 1910-1913
Author(s):  
Jian Rong Du ◽  
Zu Yi Zheng ◽  
Jun Hua Wan ◽  
Yi De Wang ◽  
Zhong Min Wan ◽  
...  

Three heat exchangers, all of which have 38 tubes in total and 6 passes, with different tube arrangements were simulation investigated in laboratory. The effect of flat tube distribution on heat transfer performance and pressure drop characteristic was simulation investigated. The effect of different air velocity and flow on heat transfer performance and pressure drop characteristic was simulation investigated too. The results show that similar tube distribution has little effect on heat transfer but has great effect on pressure drop. It was found the tube arrangement from first pass to sixth pass is 10,9,6,5,4,4 has the best heat transfer performance and its pressure drop is small. The heat transfer and pressure drop increase with the air velocity and refrigerant flow.


Author(s):  
Yan Yan ◽  
Dong Jixian ◽  
Tang Wei ◽  
Feng Shiyuf

An approach to design multi-channel cylinder dryer was proposed. The heat transfer performance and flow characteristic under various structural parameters were analyzed. First, an experiment was designed and set up to measure the condensing heat transfer coefficient and the pressure drop in order to verify the applicability of the Cavallini’s correlation. Then, the relationship among the count of channels, aspect ratio, spacing ratio, width, height and hydraulic diameter of a channel was given. Finally, the correlation of condensing heat transfer and the homogeneous model were introduced in order to observe the heat transfer performance and flow characteristic of the multi-channel cylinder dryer affected by different structures. The study reveals that the structural parameters including count of channels, aspect ratio, spacing ratio of a channel dramatically influence the condensation heat transfer coefficient and frictional resistance of the steam. Based on the selected paper machine, it is suggested that the overall performance of the multi-channel cylinder dryer is best if the count of channels is 150–200, the aspect ratio is 1:3 and the spacing ratio is 1:1–1:3.


2014 ◽  
Vol 701-702 ◽  
pp. 1233-1236
Author(s):  
Lv Xian Zeng ◽  
Zu Yi Zheng ◽  
Jun Hua Wan ◽  
Xi Chen ◽  
Zhong Min Wan ◽  
...  

Three heat exchangers, all of which have 38 tubes in total and 6 passes, with different tube arrangements were manufactured to be experimental investigated in laboratory. The effect of flat tube distribution on heat transfer performance and pressure drop characteristic was experimental investigated. The effect of different air velocity and flow on heat transfer performance and pressure drop characteristic was also experimental investigated. The results show that similar tube distribution has little effect on heat transfer quality but has great effect on pressure drop. It was found the third arrangement has the best heat transfer and its pressure drop is small. Thus the third arrangement is the best solution. The heat transfer and pressure drop increase with the air velocity and refrigerant flow, so a proper value should be chosen, it was found that the simulation results were mainly agreement with the experimental results.


Author(s):  
Yigang Luan ◽  
Shi Bu ◽  
Haiou Sun ◽  
Tao Sun

Matrix cooling is one kind of internal cooling structures applied to protect turbine blades. This paper investigated the flow field and heat transfer performance in matrix cooling channels experimentally and numerically. A testing section (rib angle of 45-deg, rib thickness of 30mm, rib height of 30mm and sub-channel width of 30mm) made of Plexiglas was build and connected to a wind tunnel sysytem. And Transient Liquid Crystal (TLC) technique was applied to obtain the detailed heat transfer distribution on the primary surface inside the matrix cooling channel. The experiment was performed under different Reynolds numbers varying from 18428 to 28327, based on the channel inlet hydraulic diameter; also the overall pressure drop across the channel was measured. Experimental results were used to calibrate the numerical solution obtained by computational fluid dynamics (CFD) method. During the numerical simulation process, structured grids and k-w turbulence model was employed. And a good agreement is obtained between experimental and CFD results for both pressure drop and heat transfer performance. Channels of various structural parameters (rib angle, rib thickness and sub-channel width) were then studied by numerical simulation, three rib angles (30-deg, 45-deg and 60-deg), three rib thicknesses (1.8mm, 3mm and 5mm) and three sub-channel widths (3mm, 5mm and 9mm) were considered, with the rib height 3mm for all the cases. Numerical results showed that the sidewall turnings made the greatest contribution to heat transfer enhancement but caused very large pressure drop meanwhile. The overall heat transfer and pressure drop increase with rib angle and rib width but decrease with sub-channel width. The thermal performance factor decreases with rib angle and rib width, while it showed a non-monotonic dependency on sub-channel width. Among the three structural parameters, rib angle has the most significant effect on the performance of matrix cooling channel.


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