TABLE OF CONTENTS The use of steam provides an ideal way to deliver just the right amount of heat energy to a point of use, to help with product manufacture or to provide an acceptable environment. The story of steam efficiency begins at the boiler (which is discussed in Chapter 10) but it does not end until the energy carried by the steam is transferred appropriately and the resulting hot condensate is returned to the boiler. Control of steam is necessary throughout the plant if the performance designed into the system is to be achieved and maintained. However, the natural laws which steam obeys are few in number and are easy to understand. Following them allows efficiencies to be achieved which would be envied with most other energy-distribution systems.
Two of the laws of thermodynamics and two of the laws of motion will cover almost all needs. In the simplest terms, it can be said that:
Energy is not destructible. It can always be accounted for, and if it disappears at point A then it reappears in equal amount at point B. This ensures that the world is a consistent place, that energy does not mysteriously appear from or disappear to nowhere, and that the Steam Tables can be relied on always to provide information on the properties of steam.
Heat flows from higher-temperature to lower-temperature objects without any help. It follows that the rate of flow will vary directly with temperature differences, and inversely with...
