Page 170 - Boiler plant and distribution system optimization manual

Over 100 Ways to Improve Efficiency 155

a year savings with HTW. Over a life cycle of 25 In Europe energy engineers have come up
years the savings was over $14 million. with the rule of thumb that it takes 49 times more
energy to move a unit of thermal energy from
point A to point B than to move the same ener-
12. SATELLITE BOILERS gy as fuel. This may not be the specific case in
all applications, but it is definitely something to
Cost consider in the case of satellite boiler projects in
Moderate to High old central steam systems.

Potential Savings Advantages/Disadvantages
Very High The cost of installing satellite boilers and the
permitting process can be quite high, but the sav-
Description ings can be very high in both maintenance costs
Once during the days when coal was King and and in energy savings.
after Heavy Fuel Oil took its place, large central
plants and extensive steam distribution systems
were built to accommodate the central fuel supply 13. ADJUSTABLE SPEED DRIVES
and need for skilled plant operators for safety and
Cost
reliable operations on a 24 hour basis month after
Moderate
month year after year. Distribution system losses
can be very high and it has been found the best
Potential Savings
way to eliminate distribution system losses is to
Moderate to high.
eliminate the distribution system. Originally, cen-
tral plants were designed around the use of coal
Description
because it was the only fuel available and now
When pumps and fans operate at higher rpms
many facilities have miles of old and questionable
than required for a particular load, electrical en-
distribution systems which were built before the
ergy is lost. The pump and fan laws apply which
day of the reliable and safe satellite boilers. When
states that the energy used varies with the cube of
you see brown grass above buried steam lines in
the rpm. Large savings can be accomplished by
the summer and melted snow over the distribu-
reducing the rpm of rotating equipment. Variable
tion system in the winter, you are probably looking
speed drives are a new dimension in the cost ef-
at heat losses from buried steam and condensate
fective management of plants. For example, if the
piping. Every foot of piping is a possible source
speed of a pump or fan is reduced by one half,
of leaks, energy losses, acid corrosion and other
there is a 88% reduction in energy use.
maintenance problems. Rain soaked and degraded
insulation, flooded systems, steam plumes along
Advantages/Disadvantages
the steam mains in streets and fields and cold or
Many plants have successfully applied ad-
lost condensate are all indicators of major distribu-
justable speed drives to boiler operations. Ad-
tion system problems.
justable Speed Drive (ASD) is becoming a proven
The central steam plant can be a huge lia-
way to save electrical costs.
bility; one only has to analyze steam production
during warm weather or holidays to discover that
large losses exist. Reliable and safe control tech-
14. CONVERT TO INFRARED HEATERS
nology and the availability oil and gas supplies
now make individual satellite boilers a safe and
Cost
efficient way to avoid these large distribution sys-
Moderate
tem losses.