12-12-2012, 11:44 AM
Training Manual on Energy Efficiency
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Availability:
Availability is one of the important criteria in the selection of a fuel. It is
desirable to select a fuel that is indigenous and is locally available.
It is desirable to select a fuel that is easy to handle; and, for storage, adequate
space is required so that the fuel can be stored safely.
Cost is a key deciding factor for any management.
The constituent properties are important from the perspectives of storage,
handling, preparation, and combustion equipment performance.
The calorific value of a fuel is the measure of energy content; it is reported
as either gross calorific value (GCV) or net calorific value (NCV), units being
kCals/kG. The difference between the two calorific values is the latent heat
of condensation of the water vapor produced during the combustion process.
Efficiency is reported both ways (GCV as well as NCV basis). It is important to
note that the efficiency value reported with NCV basis would be higher than
the value reported with GCV basis.
The presence of sulphur in fuel is related to cold end corrosion in cool parts
of the chimney/stack, pre-heated air, and economic factors as the sulphur
content determines the minimum stack temperature for avoiding acid dewpoint
corrosion in a stack. This means higher losses from the stack when sulphur
content in the fuel is higher.
Two types of analysis, proximate and ultimate analysis, are used. Ultimate
analysis is at the elemental level, and includes carbon, hydrogen, nitrogen,
sulphur, etc, and is often useful in design, while proximate analysis gives the
broader composition of carbon, volatile matter, moisture, and ash.
INTRODUCTION
A boiler is an enclosed pressure vessel that provides means for combustion
heat to be transferred into water until it becomes steam. The steam under
pressure is then usable for providing heat for an industrial process.
When water is boiled into steam, its volume increases about 1,600 times,
producing a force that is almost as explosive as gunpowder. This makes a
boiler an extremely dangerous piece of equipment that must be treated with
utmost care.
PERFORMANCE EVALUATION OF BOILERS
The performance of a boiler, which include thermal efficiency and evaporation
ratio (or steam to fuel ratio), deteriorates over time for reasons that include
poor combustion, fouling of heat transfer area, and inadequacies in operation
and maintenance. Even for a new boiler, deteriorating fuel quality and water
quality can result in poor boiler performance.
[attachment=43478]
Availability:
Availability is one of the important criteria in the selection of a fuel. It is
desirable to select a fuel that is indigenous and is locally available.
It is desirable to select a fuel that is easy to handle; and, for storage, adequate
space is required so that the fuel can be stored safely.
Cost is a key deciding factor for any management.
The constituent properties are important from the perspectives of storage,
handling, preparation, and combustion equipment performance.
The calorific value of a fuel is the measure of energy content; it is reported
as either gross calorific value (GCV) or net calorific value (NCV), units being
kCals/kG. The difference between the two calorific values is the latent heat
of condensation of the water vapor produced during the combustion process.
Efficiency is reported both ways (GCV as well as NCV basis). It is important to
note that the efficiency value reported with NCV basis would be higher than
the value reported with GCV basis.
The presence of sulphur in fuel is related to cold end corrosion in cool parts
of the chimney/stack, pre-heated air, and economic factors as the sulphur
content determines the minimum stack temperature for avoiding acid dewpoint
corrosion in a stack. This means higher losses from the stack when sulphur
content in the fuel is higher.
Two types of analysis, proximate and ultimate analysis, are used. Ultimate
analysis is at the elemental level, and includes carbon, hydrogen, nitrogen,
sulphur, etc, and is often useful in design, while proximate analysis gives the
broader composition of carbon, volatile matter, moisture, and ash.
INTRODUCTION
A boiler is an enclosed pressure vessel that provides means for combustion
heat to be transferred into water until it becomes steam. The steam under
pressure is then usable for providing heat for an industrial process.
When water is boiled into steam, its volume increases about 1,600 times,
producing a force that is almost as explosive as gunpowder. This makes a
boiler an extremely dangerous piece of equipment that must be treated with
utmost care.
PERFORMANCE EVALUATION OF BOILERS
The performance of a boiler, which include thermal efficiency and evaporation
ratio (or steam to fuel ratio), deteriorates over time for reasons that include
poor combustion, fouling of heat transfer area, and inadequacies in operation
and maintenance. Even for a new boiler, deteriorating fuel quality and water
quality can result in poor boiler performance.