Validation of the surge model and lessons learnt from commissioning of the Shuweihat Water Transmission Scheme, UAE

摘要

This paper presents a validation of the surge modeling results as well as lessons learnt from the commissioning test of the Shuweihat Water Transmission Scheme in the UAE. The Scheme is divided in two systems, The first system (Lot A) transmits water from Shuweihat to Mirfa (100 km). The second (Lot C) is from Mirfa to Mussafah (150 km). The focus of this paper is on the model predictions and field data recorded by the SCADA system during full pump trip and valve closure events. The validation was performed during the commissioning test and showed a perfect match between the prediction and measurement of pressure and flow of the first wave. This paper also intends to highlight lessons learnt during the commissioning test and in particular the major risk that is caused by inaccurate manufacturer data. On the first day of the commissioning test, a near incident took place where the pressure during valve closure unexpectedly exceeded the pressure rating by 16%. Damage to the pipeline was avoided by pressing the emergency trip push-button of the pumps thereby preventing the pipeline from being exposed to the full pressure rise. The post-incident investigation revealed that the control valve characteristics provided and certified by the manufacturer were inaccurate. A difference in Kv of up to 20% was measured for valve positions below 40% open and the valves were fully closed at 5% opening. The control valve characteristics were recalibrated on site and the valve closure pattern was adapted. The commissioning test was resumed and completed flawlessly.