時域反射法濃度儀於水庫抽泥工程之應用

在抽泥浚渫作業時產生的非穩態（unsteady）高濃度劇變環境、泥砂組成比例及粒徑大小影響，使得泥砂濃度即時量測極其不易。本研究針對抽泥工程高濃度環境，提出時域反射法（Time Domain Reflectometry, TDR）濃度儀的儀器率定考量，以及TDR導波器的型態調整，並進行大量實測進行量測效能評估。結果顯示TDR濃度儀只需單一感測頭即可由清水量測至高濃度泥漿水體60萬ppm，且不受淤泥粒徑分佈變化之影響。經實際運用在曾文水庫與南化水庫抽泥浚渫作業進行量測，TDR濃度儀量測精度及穩定性頗佳，較現有超音波與光學儀器聯合應用之合格率高出甚多，TDR濃度儀量測值經第三公正單位檢驗，合格率可維持在90%左右。

關鍵字

時域反射法；泥砂濃度；水庫抽泥

並列摘要

This study adopted the time domain reflectometry (TDR) method for sediment concentration measurement with special consideration in system parameter calibration and modification of the probe’s outer conductor, making it suitable for the environment of reservoir dredging operation. Experimental evaluation results show that the TDR method only require a single sensing probe in order to perform concentration measurement from clear water to highly concentrated slurry of 600,000 ppm, independent of particle size distribution. The TDR method was further evaluated in the concentration measurement of sludge pumping and dredging operation of Zengwun Reservoir and Nanhua Reservoir. The proposed TDR measurement system was tested in highly unsteady concentration environment with drastic changes. It was found to have good performance in both measurement accuracy and efficiency, with much higher qualified rate than existing ultrasonic and optical instruments combined.