AMP Projects Emergency Closure Gates – A Design Perspective

摘要

Four hydroelectric projects, owned by AMP (American Municipal Power, Inc.), are currently under various stages of construction on the Ohio River, which jointly comprise the current largest new hydroelectric development in the United States. Each of these projects has almost similar low head generating unit layout, using bulb turbines, which places the emergency closure gates (to protect the units against runaway) on the downstream side of the units instead of such gates’ conventional upstream location. The downstream location has helped reduce the size of the gates substantially, while, at the same time, also protecting the bulb of the turbine from water jet emanating from the bottom of an upstream located gate, when operated against flow. Still, each of the emergency closure gates is fairly large in size, approximately 37-ft. by 37-ft. Each gate is a fixed wheel type, capable of gravity closure against flow, operated by a submersible hydraulic cylinder. The special features of these emergency closure gates include the following: 1. Their large size, especially the width. 2. Circular openings in the web plates of gate’s horizontal beams to accommodate the hydraulic cylinder barrel, as the gate moves up, to minimize the total height of the gate/cylinder assembly; this will maintain the operating cylinders mostly within the powerhouse concrete, protecting them from the seasonal floods that inundate these powerhouses. 3. Seal against water pressure from headwater side as well as tail-water side. 4. Each gate’s bottom and embedded sill beam are shaped trapezoidal to be close to the circular profile of the water conduit at the location of the gate bottom. 5. Provision of a flushing system to flush trash that may accumulate at the corners of the gate sill, before the gates are closed. 6. Use of environment friendly hydraulic fluid. 7. Gates fabricated and shipped in sections for assembly in the field. The paper describes the above features and relevant explanations.