The Analysis and Development of Large Industrial Steam Systems

Abstract

Chemicals, petroleum, pulp and paper, and many other industries depend heavily on extensive complex steam systems for thermal and mechanical energy delivery. Steam's versatility and desirable characteristics as both a heat transfer medium and a working fluid has fostered and perpetuated this dependency throughout industrial history. Many large process operations, however, have not developed their steam systems to keep pace with rapidly changing energy economics. As a result, the use of steam on industrial plants seldom approaches the optimum levels of first or second law efficiency. At each of many industrial complexes today, tens of millions of energy dollars per year are literally wasted.

This paper describes some case histories comparing actual and optimum steam system configurations, and operational concepts. Highly effective steam system analytical techniques developed and used by the author are discussed. These include "energy level" mass balancing; the "three-branch" thermodynamic system; and powerful sophisticated digital computer steam system models. These latter are really "working models" on which development options can be tried and actively evaluated for economic and technical feasibility.

The principal of steam as a plant-wide integrating energy system is explained and demonstrated with examples. These show how a properly structured and effectively operated steam system can increase operational flexibility and facilitate the practical implementation of many energy conservation opportunities in process and plant service areas.