Peak Performance by Design: Planning optimizes chilled-water efficiency

摘要

Proper design of all aspects of a chilled-water system will result in higher returns and greater revenue growth for an organization's district energy investment. Lack of a comprehensive system design - one that includes customer Delta T performance - leads to poor overall performance in many chilled-water systems. This is evidenced by low chilled-water temperature rise and the subsequent inability of plant operators to obtain full capacity from either their water-chilling equipment or their most expensive component, the piping distribution system. Customer buildings are an integral part of a centralized chilled-water system. If they under-perform (return too low a Delta T), everyone on the system - and the system itself - suffers. Many building systems' overall system Delta Ts are poor: The best systems rarely exceed 18 degrees F, average systems run along at 6 F to 12 F, and the worst systems are at 2 F to 3 F. The unfortunate consequences of under-performing buildings are that the distribution system's overall heat-transfer rate is greatly reduced, the costs of producing chilled water go up, and capital equipment that was purchased cannot even be put on line. The result is a decline in the district system's ability to serve additional customers.