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姓名 曾彥碩(Yen-shuo Tseng) 查詢紙本館藏 畢業系所 能源工程研究所 論文名稱 不同集管型式多流道熱交換器流動分佈研究 相關論文 檔案 [Endnote RIS 格式]
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摘要(中) 摘要
本研究利用透明板式熱交換器，以水和空氣為工作流體，模擬冷媒在蒸
發器入口時之狀態，雷諾數範圍從50 到250，利用攝影機拍攝進行可視化，
觀察不同條件下的流動分佈現象，實驗參數包括不同入出口配置、入口大小、
流道和板片間距及擋板在集管內的配置。
實驗結果得知入口集管內部的流譜對流動分佈有明顯的影響，擋集管
上半部的配置可以使液體氣體在集管內混和均勻，使熱交換器的進出口壓
降低於無擋板的配置，整體的流動分佈與無擋板的配置相同。Z 型的入出口
配置相較於U 型有更好的流動分佈，熱交換器進出口壓降U 型則高於Z 型。
板片間距2mm 比板片間距4mm 有更好的流動分佈，因為板片間距2mm 的
集管長度為4mm 的一半，熱交換進出口壓降也較小。不同的入口管徑會改
變集管內的流譜，越小的入口管徑液氣混和區域較長，流動分佈較好，壓降
隨著入口管徑縮小而上升。
關鍵字；板式熱交換器，分佈不均，擋板，可視化。摘要(英) Abstract
In present study, the test section has used a transparent plate heat exchanger
to visualize flow distribution. Using water-air flow to simulate refrigerant’s
condition at the entrance of evaporator. The range of experiments are from
Reynolds number 50 to 250. The experiment has been test with different inlet and
outlet (U-type, Z-type) configurations, inlet diameters, and baffle (baffle on top
and bottom of header) arrangements.
The results shows that the flow pattern in inlet of header has significantly
affect the flow distribution in heat exchanger. The header which has the upper
baffle arrangement has uniformly mix of air and water. It also reduce the pressure
drop compare with no baffle arrangement. The baffle arrangements doesn’t
increase the flow distribution in heat exchanger. Z-type outlet configuration
shows the better flow distribution than U-type outlet configuration. The higher
pressure has found in U-type outlet configuration. 2mm plate spacing show the
better flow distribution than 4mm plate spacing, because the header length is
longer in 4mm plate spacing. The pressure drop is higher with 4mm plate spacing.
The inlet diameter also affect the flow pattern inside of header. Air-water mix
region is bigger with small inlet diameter. It’s not only increasing the flow
distribution but also pressure drop of heat exchanger.
Keywords: Plate heat exchanger, mal-distribution, baffle, visualization.關鍵字(中) ★ 板式熱交換器
★ 分佈不均
★ 擋板
★ 可視化關鍵字(英) ★ Plate heat exchanger
★ mal-distribution
★ baffle
★ visualization論文目次 目 錄
摘要 .......................................................................................................... i
Abstract ................................................................................................... ii
目錄 ........................................................................................................ iii
圖目錄 .................................................................................................... iv
表目錄 ..................................................................................................... v
符號說明 ................................................................................................ vi
第一章 前言 ........................................................................................... 1
1.1 研究背景與動機............................................................................ 1
1.2 研究目的 ....................................................................................... 4
第二章 文獻回顧 ................................................................................... 5
2.1 兩相流體在多個平行流道內流動分佈不均的原因 ...................... 6
2.1.1 平行流道和集管擺設方向 ....................................................... 7
2.1.1.1 垂直的集管 ........................................................................ 8
2.1.1.2 水平的集管 ...................................................................... 10
2.1.2 入出口管的配置 .................................................................... 10
2.1.3 流體性質的影響 .................................................................... 12
2.2 集管的設計對流動分佈不均勻改善 ........................................... 13
2.2.1 平行流道管路在集管的插入深度 ......................................... 13
2.2.2 其他改善集管內流動不均的方法 ......................................... 17
2.3 總結 .............................................................................................. 21
第三章 實驗方法 ................................................................................. 22
3.1 測試段 .......................................................................................... 22
3.1.1 板片幾何................................................................................ 22
3.1.2 板式熱交換器 ........................................................................ 23
3.1.3 擋板 ....................................................................................... 25
3.2 實驗系統 ...................................................................................... 27
3.3 實驗參數 ...................................................................................... 28
3.4 實驗量測設備 .............................................................................. 29
3.4.1 溫度量測................................................................................ 29
3.4.2 差壓量測................................................................................ 31
3.4.3 流量量測................................................................................ 32
3.4.4 影像拍攝設備 ........................................................................ 32
3.5 實驗步驟 ...................................................................................... 33
3.6 數據換算 ...................................................................................... 34
第四章 實驗結果 ................................................................................. 36
4.1 不同入出口配置之流動分佈 ....................................................... 36
4.1.1 入出口同側配置(U 型) .......................................................... 37
4.1.2 入出口不同側配置(Z 型) ....................................................... 40
4.1.3 U 型及Z 型配置比較 ............................................................ 44
4.2 不同板片間距之流動分佈 ........................................................... 45
4.2.1 不同板片間距流動分佈比較 ................................................. 50
4.3 入口管徑對流動分佈的影響 ....................................................... 51
4.3.1 入口管徑19 mm .................................................................. 51
4.3.2 入口管徑14 mm .................................................................. 55
4.3.3 不同入口管徑比較 ................................................................ 58
4.4 擋板排列形式對流動分佈的影響 ............................................... 59
4.4.1 擋集管上半部 ........................................................................ 59
4.4.2 擋集管下半部 ........................................................................ 62
4.4.3 不同入口管徑比較 ................................................................ 65
4.5 壓降 .............................................................................................. 66
4.5.1 不同入出口配置壓降 ............................................................. 66
4.5.2 板片間距 ................................................................................ 68
4.5.3 入口大小 ................................................................................ 70
4.5.4 擋板排列 ................................................................................ 72
4.6 壓降比較 ...................................................................................... 74
第五章 討論 ......................................................................................... 75
5.1 入口流譜對流動分佈的影響 ....................................................... 75
5.2 不同入出口配置流動分佈 ........................................................... 78
5.3 不同板片間距流動分佈 ............................................................... 80
5.4 入口管徑之流動分佈 ................................................................... 81
5.5 擋板排列形式對流動分佈的影響 ............................................... 82
第六章 結論 ......................................................................................... 84
參考文獻 ............................................................................................... 86參考文獻 參考文獻
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87
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機械工程研究所碩士論文，中壢。指導教授 楊建裕(Chien-Yuh Yang) 審核日期 2015-1-22 推文 plurk
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