超高壓電纜地下洞道冷卻氣流模擬分析

Airflow Cooling Simulation and Analysis for Extra- high Voltage Cable in Underground Tunnel

陳慶豐(Chin-Feng Chen)

指導教授 ： 王文博

國立臺北科技大學/機電學院/冷凍空調工程系所/碩士(2005年)

https://doi.org/10.6841/NTUT.2005.00145

摘要

近年台灣經濟發展快速，人口密集都會區及科學園區用電急遽增加，尤其是高科技產業中半導體及光電產業更是供電重點，故傳統高架輸配電份份轉入地下，唯地下管線以往的埋設方式，對未來之擴充無法提供周詳且長遠的規劃及供電品質，尤其佈設施工時常造成其他管線的損壞、道路之挖埋與交通阻塞等諸多問題，這對現代化社會無論是景觀或安全或維護管理都會造成非常大的影響，共同管道之應用是現代都會區或科學/工業園區必走之途徑。唯超高壓電纜在共同管道中溫度控制不超過37℃對供電的效率及安全可靠度均非常重要！
故本研究針對共同管道中「超高壓電纜地下洞道之冷卻系統」，以興建成本最低但能滿足冷卻效益之「通風冷卻」方式，故探討在台灣夏季及冬季通風豎井設置抽吸式（豎井1機械式抽風、豎井2自然通風）、送風式（豎井1機械式送風、豎井2自然通風）及推拉式（豎井1機械式抽風、豎井2機械式送風）三種通風方式，比較三種之通風冷卻效果，本論文採用商用氣流模擬分析軟體FLOVENT進行三維電腦模擬分析，並計算電纜洞道內的溫度場、速度場。
經由研究設計之3回線共45,000W之161kV電纜發熱量，在外氣溫度30℃及18℃的條件下，抽吸式、送風式及推拉式三種通風方式都可達到要求的冷卻效果(37℃以下)，外氣溫度30℃之下洞道溫度約為35.4℃，外氣18℃下洞道冷卻效果約可達23.3℃，冷卻區間也都可達1000m，三種通風方式差異不大，可針對應用之需求選用。

關鍵字

共同管道 ； 地下電纜 ； 洞道通風冷卻 ； 計算流體力學

並列摘要

Electricity supply has become a significant issue as the population and industries grow massively in metropolitan areas and industrial parks over the past decades. It also plays a greater role as for high-tech industries especially in the semiconductor and Electro-Optical fields. Traditionally, we have elevated and underground power lines to provide electricity. As the increases of the public and environmental awareness, more elevated power lines goes underground. However, underground power lines encountering unavoidably problems in cable capacities and stability with larger demand. Furthermore, during the underground tunnels constructions, it’s often the result in damaging other underground pipes, causing traffic jams and road repavement, which makes destructive conditions for road safety, cityscape and maintenance of power lines. Therefore, an underground utility tunnels shall provide a more efficient and long-lasting quality for metropolitan areas and industrial parks.
As we know, the internal temperature of the underground utility tunnels shall not exceed 370C. This is an important factor to maintain the quality, efficiency and safety of the extra-high voltage power line. This research will analyzing a variety of methods for cooling extra-high voltage power lines in the underground utility tunnel. The purpose is seeking for a better air ventilation cooling method with low initial cost and high efficiency. Three major types of ventilation methods were studied and compared as following: Aspiration, Forced draft and Aspiration draft. Each method consist two ventilation shafts. If Aspiration is adopted, one shaft will be operated by mechanical (suction) ventilation and the other operated with natural ventilation. Forced draft is adopted, one shaft will be operated by mechanical (supply) ventilation, the other one operated by natural ventilation and Aspiration draft with two shafts, both operated by mechanical (supply/suction) ventilations.
In this paper, FLOVENT（FLOVENT business software）was adopted to process the 3D computer simulation analysis and calculate temperature and speed field tests with the power line inside the underground tunnel. Three circuits were designed and based on the heat losses of 161kV. Results of experiments showed that under external temperature of 300C and 180C, Aspiration, Forced draft and Aspiration draft all successfully maintain the internal temperature below 370C within 1000 meters. Be more specific, when external temperature was below 300C, temperature in the tunnel was approximately at 35.4℃while external temperature was below 18℃, temperature in the tunnel could be kept at 23.3℃. General speaking, there aren’t much of differences between the three ventilation methods. In conclusion, Aspiration, Forced draft and Aspiration draft can be adapted by users on demand.

並列關鍵字

Common Duct ； Underground Power Cable ； Tunnel Ventilation and Cooling ； Computational Fluid Dynamics

參考文獻

[9] 勢流科技股份有限公司，FLOVENT使用者操作手冊4.2版，民92年。

[1] 台灣電力公司，台電系統發電廠分佈圖，http://www.taipower.com.tw/home15.htm民國91年12月。

[2] 台北市政府新建工程處，台北市已完成共同管道線路圖， ncp.tcg.gov.tw/ncp/admin/upload/940131.doc，民國94年1月。

[3] 日本電氣協同研究第53卷第3號，〝地下電纜送電容量設計〞，p.104~139，平成10年1月。

[4] 楊新乾，共同管道工程，初版，詹氏書局，台北，民81。