A Method of Defining Availability,Service and Output Factors of Steam Boilers

The availability of a boiler is an indication of its reliability and effective performance, and may have as important an influence on the total cost of steam and power (including capital charges) as the efficiency. There are, however, no generally accepted definitions of availability and, in consequence, many of the figures quoted in the literature are useless for comparative purposes. The paper, therefore, puts forward definitions of availability on both gross and net bases.

In addition, two other factors are required completely to evaluate boiler performance, and definitions of these, which are called ‘service’ and ‘output’ factors, are also put forward.

All these factors have been used with advantage in an industrial concern for some years now and, after discussing them, it is suggested that they should be adopted generally.