電漿顫動與工作氣體溫度控制的研究

Abstract

為配合「環境電漿技術之發展與應用」施政目標，開發高功率直流電漿火炬技術以期促使國家環境保護技術朝零廢棄物的目標發展。本計畫之主要目的是期望能提高直流電漿火炬的使用效能。然而，直流電漿火炬內部的顫動(Fluctuation)現象影響火炬的使用壽命、火焰穩定度與電漿噴塗的品質。在近年來已發表文獻中指出，直流電漿火炬顫動現象與低溫邊界層(Cold boundary layer)有關。因此，直流電漿火炬可能可以透過控制工作氣體溫度改善顫動行為。本計畫擬建立溫度控制之數學模式，並設計工作氣體加熱器與溫度控制器，驗證理論分析與控制器設計之成效，期望經由溫度控制方式改變低溫邊界層以改善電漿火炬的顫動現象。另外，本計畫也將進行氣體溫度控制實驗，量測顫動現象與氣體溫度的相關數據資料，找出電漿顫動與進氣溫度的關係，進而改進火炬的顫動現象。此外，我們也將研擬直流電漿火炬顫動現象的改善對策以提供未來相關研究人員參考。

It is known that a DC plasma torch might exhibit fluctuation behavior which might affect the performance of the torch. A recent study shows that such a fluctuation behavior phenomenon might be strongly linked to the internal cold boundary layer of torch, which is surrounding the arc column. One of the major goals of this project is to change working gas temperature for improving the cold boundary layer of plasma torch and hence control the behavior of the arc plasma fluctuation. First, the theoretical model of working gas heater with temperature control will be derived. It will then be used for theoretical analysis and controller design. The performance enhancement of the gas heater and temperature regulator will also be designed to verify the feasibility of the proposed schemes. In addition, an experimental verification will be covered for practical validation of the controlling the fluctuation phenomenon of DC plasma torch.