This document discusses burner management systems (BMS), including their objectives, design standards, logic, types, and interface with SCADA systems. A BMS is defined as a control system dedicated to boiler safety during startup, operation, and shutdown. The document outlines BMS logic including purge, igniter, and main flame interlocks. It describes early hardwired and solid state systems, as well as modern microprocessor-based and PLC-based BMS. PLC systems offer flexibility, redundancy, and integration with SCADA. In summary, the document provides an overview of BMS design, functionality, and system types.
4. Introduction
What is a BMS?
A Burner Management System is defined as
the following:
A Control System that is dedicated to boiler
safety, operator assistance in the starting and
stopping of fuel preparation and burning
equipment, and the prevention of mis-operation
of and damage to fuel preparation and fuel
burning equipment. 1
1. From NFPA 8501 “Standard for Single Burner Boiler Operation”
5. Burner Management Objectives
Sequence burner through safe start-up
Insure a complete pre-purge of boiler
Supervise safety limits during operation
Supervise the flame presence during
operation
Sequence a safe shutdown at end of cycle
Integrate with combustion control system
for proper fuel and air flows
6. BMS Design Standards
Each Burner Management System should be
designed in accordance with the below listed
guidelines to control and monitor all sequences of
the start-up and shutdown of the burner
National Fire Protection Association (NFPA 8501
/8502 or others)
Industrial Risk Insurers (IRI)
Factory Mutual loss prevention guidelines
Each burner management system should be
designed to accomplish a safety shutdown in the
event of an unsafe condition. (FAIL SAFE)
7. BMS Design Standards
U.S. National Fire Protection Association
(NFPA)
Governs safety system design on virtually all boilers
(regardless of the process to be used to combust the
fuel)
Requires the separation of the Burner Management
System from any other control system
Requires the use of a hardwired backup tripping scheme
for microprocessor based systems
Requires that a single failure NOT prevent an
appropriate shutdown
Factory Mutual loss prevention guidelines.
8. NFPA 8501
NFPA 8501 Standard for Single Burner
Boiler Operation
Single Burner Boilers with fuel input greater than 12.5
mBTU/Hr (Approx. 250 BHP)
Single Fuel or Combination of Fuels (Common being
Natural Gas / No.2 Oil / No. 6 Oil)
Simultaneous Firing
9. NFPA 8502
NFPA 8502 Standard for Prevention of
Furnace Explosions / Implosions in Multiple
Burner Boilers
Multiple Burner Boilers with fuel input greater than
12.5 mBTU/Hr
Single Fuel or Combination of Fuels including
Pulverized Coal
Emphasis on implosion protection (larger boilers with
induced draft systems)
10. BMS Definitions
Furnace Explosions
“Ignition of accumulated combustible mixture within
the confined space of a furnace or associated boiler
passes, ducts, and fans that convey gases of combustion
to the stack”1
Magnitude and intensity of explosion depends on
relative quantity of combustibles and the proportion of
air at the time of ignition
1. From NFPA 8502 “Prevention of Furnace Explosions / Implosions in Multiple Burner Boilers”
11. BMS Definitions
Furnace Explosions can occur with any or a
combination of the following:1
Momentary loss of flame followed by delayed re-
ignition
Fuel leakage into an idle furnace ignited by source of
ignition (such as a welding spark)
Repeated Light-off attempts without proper purging
Loss of Flame on one Burner while others are in
operation
Complete Furnace Flame-out followed by an attempt to
light a burner
1. From NFPA 8502 “Prevention of Furnace Explosions / Implosions in Multiple Burner Boilers”
12. BMS Definitions
Furnace Implosions
More common in large Utility Boilers
Caused by any of the following:
» Malfunction of equipment regulating boiler gas flow
resulting in furnace exposure to excessive induced
draft fan head capability
» Rapid decay for furnace gas temperature and
pressure due to furnace trip
1. From NFPA 8502 “Prevention of Furnace Explosions / Implosions in Multiple Burner Boilers”
13. BMS Basic Definitions
Common Terminology
Supervised Manual
» Manual Burner Lightoff with Interlocks
Automatic Recycling (Single Burner Only)
» Automatic Burner Start and Stop based on preset
operating range (ie.. Drum pressure)
Automatic Non Recycling (Single Burner Only)
» Automatic Burner Start and Stop based on Manual
command to start.
14. Types of Flame Scanners
Infrared (IR) Detectors
Single Burner Applications
More Suitable with Oil Burning Flames
Ultra-Violet (UV) Detectors
Multiple Burner Applications
More Suitable for Gas Burners and
Combination Gas / Oil Burners
Self Check Scanners
Flame Signal is interrupted at set intervals to
verify proper operation of scanner
15. Single Burner BMS Inputs
OIL
GAS
STEAM
FEEDW ATER
PSL
TSL
TSH
PSL
High Steam Pressure (D)
Low Low Drum Level (D)
PSL PSH
PSL
ATOMIZING
MEDIUM
Fuel
Gas
Press
Low
(D)
Fuel
Gas
Press
High
(D)
FT
FT
Atomizing
Medium
Press Low (D)
Fuel Oil Flow (A)
Fuel Oil Temp High (D)
Fuel Oil Temp Low (D)
Atomizing Medium Flow > Min (D)
Fuel Oil Press Low (D)
PSH
PSL
FT
PSH
PT
LSLL
LSLL
Purge Purge Air Flow (D)
Minimum Air Flow (D)
AE TE
(D) - Descrete Signal Used ByFlame Safeguard System
Common Alarm Output (D)
Remote Annunciator
(ByOthers)
SafetyShut Off &
Vent Valves
Control Valve &
Shut Off Valve
SafetyShut Off
Valves
Control
Valve
Control
Valve
SafetyShut Off
& Vent Valves
IGNITER
GAS
Flame / No Flame (D)
FS
FD FAN
HAND O FF AUTO
Li mi t s M ade
H
ol d t o Purge
S C R L M O D E
R E S E T
FUEL SELECT
G AS O I L
BURNER
O FF O N
16. BMS Logic
Burner Management Systems can be broken
down into “Interlock Groups”
Typical BMS Interlock Groups:
Boiler Purge
Igniter Header Valve Management
Main Fuel Header Valve Management
MFT (Master Fuel Trip) Logic
17. Purge Interlocks
BOILER TRIPPED
AND PURGE / RESET PB
START FD FAN
AND
PERMISSIVES SATISFIED:
- MAIN FUEL VALVES CLOSED
- NO FLAME PRESENT
- FD FAN RUNNING
- MINIMUM AIR FLOW SWITCH MADE
- WATER LEVEL SATISFACTORY
- ATOMIZING MEDIUM ON
- FUEL SUPPLY PRESSURE NOT LOW
ENERGIZE FUEL RELAY
PURGE SIGNAL TO CCS
NOT AND
START-UP
TIMER
AND
PURGE AIR
FLOW SWITCH
MADE
FD DAMPER IN
FULL OPEN
POSITION
PURGE TIMER SET
PURGE COMPLETE
REMOVE PURGE TO CCS SYSTEM TRIP
YES
NO
18. Igniter Interlocks
AND
ENERGIZE IGNITER AND
IGNITER HEADER VALVES
NOT
SYSTEM TRIP
PURGE COMPLETE
AIR DAMPER IN LOW FIRE
POSITION
FUEL VALVE IN LOW FIRE
POSITION
10 SECOND DELAY
FLAME
PROVEN
10 SEC PILOT TRIAL
FOR IGNITION
TIMER COMPLETE
AND
PERMIT FOR MAIN
FLAME
19. Main Flame Interlocks
AND
NOT
SYSTEM TRIP
IGNITER TIMER
COMPLETE
FLAME
PROVEN
10 SEC MAIN FLAME
TRIAL
TIMER COMPLETE
AND
RELEASE TO
MODULATE TO CCS
ENERGIZE MAIN
FUEL VALVES
DE-ENERGIZE
IGNITION
COMPONENTS
20. Single Burner Main Fuel Trip
FOR OIL:
- LOWFUELPRESSURE
-LOWTEM
PERATURE(HEATEDOILS)
-LOSSOFCOM
BUSTIONAIR
-LOSSOFFLAMEORFAILTOESTABLISH
-LOSSOFCONTROLSYSTEMENERGY
- POWERFAILURE
- LOWWATERLEVEL(AUXLEVELCONTACT)
- LOSSOFATOM
IZINGM
EDIUM
- EXCESSIVESTEAMDRUMPRESSURE
- HIGHOILTEM
PERATURE(HEATEDOILS)
TRIP BOILER
FOR GAS:
- LOWFUELGASPRESSURE
- HIGHGASPRESSURE
-LOSSOFCOM
BUSTIONAIR
-LOSSOFFLAMEORFAILTOESTABLISH
-LOSSOFCONTROLSYSTEMENERGY
- POWERFAILURE
- LOWWATERLEVEL(AUXLEVELCONTACT)
- EXCESSIVESTEAMDRUMPRESSURE
OR
OR
TRIP IGNITER,
IGNITER VALVES,
OPEN IGNITER
VENT
TRIP MAIN FUEL
VALVES, OPEN
VENT VALVE
(GAS ONLY)
FUEL CONTROL
VALVE TO
CLOSED
POSITION
TRIP MFT RELAY
21. BMS System Types
Early Burner Management Systems
Hardwired Systems
Solid State Systems
Microprocessor Based Systems
Fireye E110 / Honeywell 7800 series with fixed
Logic.
PLC Based Systems
Programmable Logic Controller (PLC) Based
Powerful, versatile, expandable, more reliable.
22. Early Burner Management Systems
Hardwired Systems
Relay and Timer Driven. Found on older
installations
Typical of Late 50’s, 60’s
Solid State Systems
Solid State Processors and Relays
Found on Systems provided in the 70’s and 80’s
Proprietary Hardware (ie.. Forney and Peabody)
Spare Parts are extremely hard to find.
23. MicroProcessor Based Systems
Microprocessor Based System providing:
Burner Sequencing
Ignition
Flame Monitoring
Fixed Program with Limited Configuration
Changes
Components Selected Based on Requirements
Programmers, Flame Amplifiers, Message Displays
25. MicroProcessor Capabilities
Simple, Cost Effective
Features
Selectable Flame Amplifiers / Scanners
Remote Display
Remote Data Communications via Modbus Port
Modernization kits are available to integrate with older
systems
Spare Parts Normally Readily Available
26. When These Systems are Used
“Simple” Boiler Installations
Packaged Firetube / Watertube Boilers (Steam /
Hot Water)
Single Burner
One Fuel at a Time
No Flue Gas Re-Circulation
Upgrades from Previous MicroProcessor Based
Systems
27. PLC Based Burner Management Systems
PLC Based Features
NFPA 8501, 8502
Watchdog timer
UL 508 Certification
Redundant Scanners
Logic+ Message Center
Shows program status
Displays alarms
Prompts operator
28. Each PLC based burner management system should
incorporate a number of design techniques which
help detect and act upon unsafe failure modes which
can occur in any microprocessor based system.
These design features include the following:
Critical Input Checking
Critical output channel monitoring
Electro-mechanical Master Fuel Trip (MFT) Relay
Redundant Watchdog Timers
Low Water Cut-out Monitoring During Blow Down
PLC System Basic Design Features
29. PLC Based System Capabilities
Provision for Multiple Fuel Firing
Capped gas input during curtailment
Changeover from gas to oil at any load
Simultaneous firing of waste and fossil fuels
Redundant Scanners, change scanner with fuel
Single or Multiple Burner Applications
Integration of BMS with SCADA
30. PLC Based Operator Interfaces
Features
Clear Written Messages to indicate status, required
operator interaction, trip/alarm indication
High Visibility through two lines of display
Messages reduce time consuming troubleshooting
Prioritizes Messages
» First Out Alarms
» Warning / Alarm Messages
» Status Messages / Prompts Operator
31. PLC System Layout (Typical)
Logic+ Message
Display
SWITCH SILENCE LIGHT
Door Mounted Lights / Pushbuttons
FLAME AMPLIFIER
(SINGLE /
REDUNDANT)
FIELD DEVICES
PLC CPU I/O I/O I/O I/O
I/O EXPANSION I/O
COMBUSTION
CONTROL SYSTEM
32. Benefits of PLC Based Systems
Flexibility / Reliability
Programming Software allows changes to
system
Choice of PLCs
GE / Modicon / Allen Bradley / Koyo
Choice of Flame Scanners
PPC / Fireye / Honeywell / Iris / Coen
Application Specific
Quantity of Burners / Fuels is not restricted
33. When to Use PLC Based Systems
“Complex” Boiler Installations
Larger Packaged Units / Field Erected Units
Multiple Burners
Multiple Fuels, On-line Fuel Changeovers
Flue Gas Re-Circulation
Replace Existing Relay Logic Systems
Requirement to maintain consistent control
platform (spare parts, etc..)
34. BMS SCADA Interface
BMS Systems can be integrated into a
SCADA System
Allows Remote Monitoring of Flame Status
Allows Remote Control of BMS
Events (ie.. Burner trip) can be routed to
Historical Portion of SCADA for fault
evaluation
Burner Operation can be trended over time
35. BMS SCADA Interface
Interface Methods:
PLC CPU I/O I/O I/O I/O
Communication
Interface
(If Necessary)
MODBUS
COMMUNICATION
PROTOCOL
MODBUS
COMMUNICATION
PROTOCOL
BMS LOGIC+ SYSTEM
SCADA PC
FIREYE E110 SYSTEM
37. Summary
Benefits Associated with New Burner
Management Systems
Help Improve plant safety
Help qualify for reduced insurance cost
Reduce Startup and Down Time with
comprehensive alarming and diagnostics
38. Summary
Review of Topics Discussed
Objectives of Burner Management Systems
BMS Design Considerations
Basic BMS Logic
Types of Burner Management Systems
How BMS Systems can be integrated with
Plant Wide SCADA Systems
39. 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