Transcript Boiler Efficiency and Combustion Control

Preferred Utilities Manufacturing Corp.
Fuel Oil Sizing Program Overview
Preferred Utilities Manufacturing Corporation
31-35 South St. • Danbury • CT
www.preferred-mfg.com
Introduction
 PC
Based Program
 Sizes Typical Fuel Oil Piping Systems
 Helps to determine “workability” of overall
application
 Helps to sizing suction and discharge piping
Day Tank Schematic
Determining Pump Capacity

For day tank systems





For burner systems



rate of use vs. duty cycle determines pump flow
length of time without power determines tank size
E-Gen sets – “RULE of THUMB” 7 GPH / 100kw
E-Gen sets - “RULE of THUMB” 4:1 , pump runs 25% of
time.
parallel loop, total burning rate plus total return flow
series loop, total burning rate plus return flow of last
burner only
Pick pump-motor pair with next greater flow rate

Motor HP based on PSI required
Maximum Inlet Suction
 Atmospheric
pressure (30" Hg) provides the
force to get oil into the pump
 Most pumps can produce a 20" Hg vacuum
 Good practice limits suction to a 15" vacuum
or less
 Typical piping loss is 5" Hg
 This leaves 10" Hg for static lift, or 12' of oil
 Pump should not be located more than 12'
above the bottom of the tank
Determining Inlet Suction
 Suction


at pump inlet
Add gravity head plus:
Friction losses
 Friction



loss through suction piping
convert fittings, valves, etc. to equivalent
diameters
add total length of pipe to equivalent for fittings
add loss through strainer
 Increase
pipe size or lower pump to suit
Pressure Drop through Pipe
Pressure drop
through pipe,
Number 2 Fuel Oil
Flow, Gallons per hour
Equivalent Diameters
» ball valve, full ported
» check valve, lift type
» check valve, swing type
» foot valve, poppet type
» globe valve
» gate valve, full ported
» plug valve
» 90 degree elbow
» 45 degree elbow
» Tee, through run
» Tee, through branch
3
600
100
420
340
8
18
30
16
20
60
Suction Piping Precautions
 If
both pumps in a duplex set may be run
together, use total flow in calculations
 Figure static lift from bottom of tank
 Use a 100% safety factor for strainer drop
 Use a 40 or 100 mesh strainer for #2 oil
 Use worst case viscosity in figuring loss
Priming the System
 Try
to keep pump close to tank
 Eliminate “up and over” lifts
 Add a priming funnel to the high point
 Do not allow pumps to run dry
 If possible, always use a foot valve to hold
prime
 Pressure test all suction piping
Some Terminology



Operating Pump Suction: This value is displayed on the
screen at the suction side of the pump. This value is the
total summation of all losses encountered on the suction side
of the pump.
Priming Pump Suction: This value takes into account the
vertical lift of a dry system, and may also be referred to as
the priming static lift. If a pump looses its prime, and the
piping system is dry, the static lift may not be the same as
the priming static lift. Therefore, the Priming Pump Suction
must be examined as well as the Operating Pump Suction.
This value takes into account the vertical distance of piping
that might go above the centerline of the pump, before
connecting with the pump.
S.G: Density of a fluid compared to the density of water.
Discharge Piping
 Pressure



at pump discharge
Add pressure needed at point of use plus
total gravity head and
pipe losses
 Generally,
discharge piping is smaller than
suction piping
 A Back Pressure Regulating Valve may be
used to regulate pressure at point of use
(boilers)
Viscosity as a Function of Temp.
Miscellaneous Cautions

Beware of entrained air

locate return and supply at opposite ends of tank
Avoid high lifts and “traps”
 Allow for easy priming of pumps
 Provide adequate vent lines
 Provide properly sized day tank overflow lines
 Design the system so it can be tested regularly
 Don’t overlook controls

Loading the Fuel Oil Sizing Program
Opening Window - Select New or Existing File
Discharge Piping Selection
Application Selection Page
Opening Overview Display
Suction Piping Selection
Discharge Piping Selection
Final Overview Display
Pop Up Windows
Report Printing
Example
Rule of THUMB
Exercise 1
For No. 2 Fuel Oil
Determine:
P1 and P2
Select Pump Set
Head
5 ft of No. 2 Oil =
Vacuum
4 " Hg
Head
5 ft of No. 2 Oil =
Pressure
2 psi
P1
100 feet
of 1 inch
Suction pipe
Storage Tank
10
feet
P2
300 gph
10
feet
Required
5 psi
100
feet
200 feet
of 1 inch
Discharge pipe
Example
Rule of THUMB
Exercise 2
For No. 2 Fuel Oil
Determine:
P1 running and priming, P2
ASV Spring Size
Select Pump Set
Head
5 ft of No. 2 Oil =
Vacuum
4 " Hg
Head
5 ft of No. 2 Oil =
Pressure
2 psi
Required
5 psi
ASV
100 feet
of 1 inch
Suction pipe
15
feet
17.5
feet
200
feet
P1
P2
Storage Tank
5
feet
400 gph
300 feet
of 2 inch
Discharge pipe
Pressure Drop through Pipe
Pressure drop
through pipe,
Number 2 Fuel Oil
Flow, Gallons per hour
Preferred Utilities Manufacturing Corp
For further information, contact...
Preferred Utilities Manufacturing Corporation
31-35 South St. • Danbury • CT
T: (203) 743-6741 • F: (203) 798-7313
www.preferred-mfg.com