Introduction to Energy Management
Problem: For your university or organization, list some energy management
projects that might be good “fi rst
... [Show More] ones,” or early
selections.
Solution: Early projects should have a rapid payback, a high probability
of success, and few negative consequences (increasing/
decreasing the air-conditioning/heat, or reducing
lighting levels).
Examples:
Switching to a more effi cient light source (especially
in conditioned areas where one not only saves with
the reduced power consumption of the lamps but also
from reduced refrigeration or air-conditioning load).
Repairing steam leaks. Small steam leaks become large
leaks over time.
Insulating hot fl uid pipes and tanks.
Install high effi ciency motors.
And many more
2 Solutions Manual for Guide to Energy Management
Problem: Again for your university or organization, assume you are
starting a program and are defi ning goals. What are some
potential fi rst-year goals?
Solution: Goals should be tough but achievable, measurable, and
specifi c.
Examples:
Total energy per unit of production will drop by 10
percent for the fi rst and an additional 5 percent the
second.
Within 2 years all energy consumers of 5 million British
thermal units per hour (Btuh) or larger will be separately
metered for monitoring purposes.
Each plant in the division will have an active energy
management program by the end of the fi rst year.
All plants will have contingency plans for gas curtailments
of varying duration by the end of the fi rst
year.
All boilers of 50,000 lbm/hour or larger will be examined
for waste heat recovery potential the fi rst year.
Introduction to Energy Management 3
Problem: Perform the following energy conversions and calculations:
a) A spherical balloon with a diameter of ten feet is fi lled
with natural gas. How much energy is contained in
that quantity of natural gas?
b) How many Btu are in 200 therms of natural gas? How
many Btu in 500 gallons of 92 fuel oil?
c) An oil tanker is carrying 20,000 barrels of #2 fuel oil.
If each gallon of fuel oil will generate 550 kWh of
electric energy in a power plant, how many kWh can
be generated from the oil in the tanker?
d) How much coal is required at a power plant with a
heat rate of 10,000 Btu/kWh to run a 6 kW electric
resistance heater constantly for 1 week (16 8 hours)?
e) A large city has a population which is served by a
single electric utility which burns coal to generate
electrical energy. If there are 500,000 utility customers
using an average of 12,000 kWh per year, how many
tons of coal must be burned in the power plants if the
heat rate is 10,500 Btu/kWh?
f) Consider an electric heater with a 4,500 watt heating
element. Assuming that the water heater is 98% effi -
cient, how long will it take to heat 50 gallons of water
from 70 degree F to 140 degree F? [Show Less]