Suche

Transient Control for a Multiple Booster Pumping Station and Transmission Pipeline System — Design, Testing, Adjustment, and Operation

Charles, Thomas J. / Bauer, Kenneth

Abstract

To augment and develop renewable water supplies and promote collaboration with other water providers, the East Cherry Creek Valley Water & Sanitation District (District) constructed the multiple phase Northern Water Supply Project. This drinking water transmission system consists of a Reverse Osmosis (RO) membrane water treatment facility, 31 miles of 48-inch transmission pipeline, and three pumping stations. Delivery capacity will be 47-mgd on a peak day basis with up to 10 million gallons of storage, and more than 12,000 hp of pumping capacity. The primary transient control systems proposed for the Northern Water Supply System consist of integrated equipment operation at each of the pump stations. Each pump station is equipped with combination surge anticipator valves and pressure relief valves. These valves discharge to the suction piping of each pump station and, in turn, to the storage tanks. The tanks act to absorb transient waves and regulate peak pressures on the suction side of the stations, effectively isolating the systems from pressure and transients with an air break. In addition to the surge anticipators and tanks, stroking patterns for the ball pump control valves, anti-reverse ratcheting systems, and air vacuum valves play key roles in control transients. All elements of the transient control strategy play critical roles in protecting the entire facility from damaging surge conditions and require a comprehensive maintenance strategy to maintain proper operation and protection. After construction was complete, the design concepts were verified during system startup by simulating various modes of power interruption and monitoring the response of the pumps, valves, and equipment. Pressure tracing and water storage level changes were recorded for use in evaluating the effectiveness of the transient controls. Actual system response was superimposed on the simulated predictions. Comparisons indicated consistent but inexact system response and identified that the facilities could benefit from adjustment of the system controls. By taking a start to finish approach to a complicated system design, effective transient control was assured. The demonstrated benefit of system control adjustment based testing and verification of design was an essential step in completing a successful project with full protection of the District's significant capital facility investment.