Central Heating Plants

• Introduction
• Central Systems
• Fuels
• Principles of Combustion
• Boiler Types
• Boiler Inefficiencies
• Power Plant Auxiliary Equipment
• Pollution Control Equipment
• Turbines
• Chemical Treatment
• Water Treatment
• Control Systems
• Monitoring and Controlling Performance
• System Retrofit Possibilities
• Additional Resources

Introduction

Today's facilities manager must evaluate many alternatives to meet energy demands and must make sound decisions regarding large capital expenditures for plant additions and alterations. An understanding of basic heating and power plant cycles and equipment is essential.

This chapter discusses the fuels, processes, and equipment of central heating and power plants. The discussion of fuels, fuel firing, boiler control, emission control, and operation applies generally to all sizes and types of boilers.

Boilers are the basic building blocks of any plant system for the generation of hot water or steam. Whether fueled by gas, oil, coal, or renewable fuel sources, such as biomass, boilers are used by virtually every college and university. They may be located in a central plant or distributed among various campus buildings as package boilers. The energy derived from these boilers is generally in the form of steam or hot water. Hot water can be used to heat buildings directly or steam can be used to (1) generate electricity through turbine generators, (2) heat buildings with direct steam or hot water, (3) cool buildings with steam-driven centrifugal or absorption chilled water systems, and (4) provide steam for processes. To increase plant efficiency, a variety of auxiliary equipment is available, including economizers, air preheaters, feedwater heaters, , and various heat exchangers, to maximize the use of the heat generated in the burning of fuels. In addition, other equipment, such as mechanical collectors, dust collectors, electrostatic precipitators, baghouses, scrubbers, and wastewater treatment systems, are often required to satisfy emission standards.

Reliable performance of the plant system is critical to institutional operations. Efficient delivery of energy services to control operating costs is equally important. It is not uncommon for utility operating expenses to approach one-half of the facilities budget. For these reasons, the responsible facilities manager must devote considerable time to ensure reliable utility service at the least possible cost. This chapter will cover the fundamental operation and maintenance procedures that the facilities manager can use to maximize the inherent advantages of a central plant system and achieve cost-effective and reliable service.