|
|
|
 |
|
|
 THE CHALLENGE
Boilers are employed in numerous industries and a multitude of applications,
which may entail the supply of steam to several remote user locations from a
central steam plant (District Heating)
or may simply consist of a single dedicated
boiler sized for a single process. In all cases, and regardless of the type of
fuel used to fire the boiler, overall boiler efficiency is critical to operating
costs and environmental compliance issues.
In an effort to maximize the use of the heat of combustion, several approaches
have been used to capture the waste heat in the flue gas, economizers and air
heaters are the most common examples. The economizer, for example, adds heat to
the boiler feed water (BFW) after it leaves the deaerating heater and before it
enters the boiler. The more heat you can capture from the flue gas, the higher
your boiler efficiency will be.
The Answer
Direct Contact Inc. (DCI) Heat Recovery Systems capture wasted heat (both the
sensible and latent heat) by utilizing cool BFW makeup and a unique direct contact
process. This approach is capable of extracting much more heat from the hot flue
gas than can be captured by an economizer alone. A DCI Heat Recovery System is
designed to be “transparent” to the boiler operation and can be used with or
without an economizer or air heater.
The Direct Benefits
The overall heat efficiency of your system can be increased significantly
(as much as 6%) by using a Direct Contact Inc. (DCI) Heat Recovery System. Facilities
that return a large portion of their condensate will see a relatively small
increase in efficiency but, as the amount of condensate returned decreases, the
potential efficiency increases proportionally. For example, a DCI
system installed on a typical boiler, already fitted with an economizer, burning
natural gas at 15% excess air and returning 50% of its condensate, would result
in an increase of approximately 3% efficiency increase. The same system, with a zero condensate
return, would increase boiler efficiency by 6%. Energy or fuel savings can quickly add up to offset the initial
purchase and installation cost of the DCI Heat Recovery System and start to
contribute to the facility’s bottom line profitability.
Where there is a nearby hot water heating requirement (e.g. laundry, institutional
showers, miscellaneous industrial requirements, ect.), the displacement of steam to
heat the potable or other water source to useful temperature can provide additional
justification for such a system. Supplementary benefits are realized when you
consider that this technology also condenses the water combustion and actually
generate a positive net water flow to the system.
|
|
