中央風管系統測試調整平衡技術之探討

The Study on Testing,Adjusting and Balancing Technique for Central Air Duct System

吳廷濬(Tin-Chun Wu)

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)

摘要

中央風管系統進行測試調整平衡時，需使設備系統正常運轉、空調箱總風量調整於設計值±10%範圍內、儀器校正完畢並準備齊全，以取得量測正確資料，使用能源管理系統(Energy Management Control System)監測調整，搭配比例式平衡方式(Proportionally Balancing Method)進行出風口風量量測較直接調整出風口風量實際誤差值更為精確。落實測試調整平衡，可使得室內氣流與溫度分佈均勻，並且避免因局部氣流溫度不符需求時，徒增空調箱風量或降低冰水溫度，造成能源浪費。
中央風管系統工程現場依據實際現場案例取得各項分析基本參數，並經ASHRAE 2001基礎篇-風管設計，建立風管管道及附件壓降分析模式，採用電腦軟體excel以數學模擬中央風管系統各項壓降損失，包括主風管損失、漸縮管損失、漸擴管損失、彎頭損失、支風管損失、分歧管損失、風門損失及出風口損失等，由兩實際案例中，探討中央風管系統不同風管路徑，系統區段對風速與風管路徑壓降之關係。經由分析探討後，由實際案例中，得知附件損失通常佔總壓降1/2以上，其中風門損失為附件損失的關鍵所在，由此可知選用風管附件之重要性。此外，經由實際案例1可知適當轉換風門型式、改變風管尺寸確實可使得區段壓降明顯改善，有助降低風管壓降，使得風車需求靜壓降低，以期達成節能省電之目的。
此數學模擬，可應用於設計階段比較風管各路徑壓降，並將壓降較大路徑予以適當修正。亦可用在風管測試調整平衡完成後，作為風管原設計參數之檢討，避免能源浪費。

關鍵字

中央風管系統 ； 測試調整平衡 ； 壓降

並列摘要

During the process of testing, adjusting and balancing (TAB) for central air duct system, it requires system stability、adjusting the total air volume of the air handling unit within the range of ±10% to design capacity、make any necessary adjustment on instruments to ensure a correct measurement data. Measuring flow volume directly from diffuser, as the result shows by using Energy Management Control System with Proportionally Balancing Method; the differential rate is more accurate than adjusting supply air volume directly from the diffuser. The purpose of testing, adjusting and balancing (TAB) is to ensure the air flow pattern can be more evenly distributed.
Based on this case; it is to obtain basic parameters from central air duct system on an actual site. As a referencing guide, ASHRAE 2001 fundamental-duct design has established the structure of pressure drop analysis of the duct and fitting. By using Excel software to simulate all pressure drops in central duct system including: main ducts, reducing/extended ducts, branch ducts, duct connectors, duct elbows, duct tees, dampers and diffusers friction-loss …etc. From the practical cases, it determines velocity and pressure drop in different paths and sectional area of the duct system. From the analysis, we know the importance of a large proportional of total pressure drop usually causes by duct fitting losses (especially in damper pressure loss). Proper damper installation and revise duct size will improve the pressure drop of sectional duct area and consequently lower pressure loss of the duct system. Furthermore, the fan operates with lower static pressure; therefore the ideal of maximum energy efficiency can be achieved.
In this mathematical simulation, we can easily apply this application and comparison to all sections in duct system during the preliminary design and correcting improper large pressure drops paths. It can also be applied after TAB, for reviewing the original design parameters and prevent more energy wastage.

並列關鍵字

Central Air Duct System ； Testing,Adjusting and Balancing ； Pressure Drop

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