CHA Canada has encountered, with many of its clients, a general lack of consensus on a future strategy for heating and/or chilled water systems. As an engineering company which specializes in power plants, cogeneration and chiller systems, we are often requested to carry out studies to determine if cogeneration is viable or if a piping distribution system should be upgraded. Only in a few instances, however, have we been requested to analyze and model the entire heating or cooling system to provide a baseline performance and economic model of the system which can be used as a basis for decisions. Without a total system approach, options tend to be evaluated individually. A total energy/total plant perspective provides a method to determine what effects changes in operation will have on present performance and economics and to allow multiple options to be investigated to provide the client with a true picture of the process for future operations.
This paper presents an example of a total system model which allows various scenarios to be investigated. It provides a client with concrete information on the effects of centralized or decentralized expansion, sizing of future units based on load growth forecasts, unit retirement schedules, possible fuel types, possible prime mover types, efficiency vs. capital cost comparisons, as well as other options. The total system modeling method provides the client with an analysis, in a graphical and tabular format, of the options that should be considered and the type of future expansion that provides the best opportunities and least risk.