Cooling Water Intake Manifold (Header) Study For The James H. Campbell Electric Power Generating Plant, Unit No. 3

Abstract

A seven-junction cooling water intake manifold was studied in a physical model and by hydraulic analysis. The manifold, also referred to as a "header", is one of four to be embedded in the bottom of Lake Michigan approximately 3500 ft offshore from the James H. Campbell Plant. Each header supports and collects water from seven dual screen intake risers (subject of a separate study). The primary objective of the study was to determine flow contribution from each of seven risers and piezometric pressures along the header. It was found that the flow rates ranged from 92 percent to 112 percent of the average flow per riser. To achieve a higher degree of uniformity, an analysis was made to determine how much additional headloss had to, be generated in each intake riser in order to produce identical withdrawal rates in all seven risers. A similar study was. Made for a partially balanced system where withdrawal rates would not fall outside the 95 to 105 percent limits. In that case, headloss generators were required in the two most downstream risers. Sharp edged nozzles were designed for Risers 6 and 7, and experimentally tested. The total piezometric pressure change through the partially balanced riser-manifold system at a total withdrawal rate of 206 cfs was determined to be 13.8 inches of water relative to the lake. The total energy headloss between the lake and the downstream end of the manifold was determined to be 10.7 inches of water.