Boiler Basics: Design & Application Differences. Presented by Steve Connor July 30, 2014

Transcription

1 Boiler Basics: Design & Application Differences Presented by Steve Connor July 30, 2014

2 What We Are Covering Today Understanding Boiler Load Boiler Manufacturing Requirements Design & Construction Details Boiler Basics: Design & Application Differences The Boiler Package Industry & Application Match-Up Types of Fueled Boilers 2

3 3 Boiler Manufacturing

4 ASME Code (American Society of Mechanical Engineering) Section I High pressure - Steam boilers above 15 psi. Hot water boilers above 160 psi (hydrostatic pressure) and/or F outlet temperature 4

5 ASME Code (American Society of Mechanical Engineering) Section IV Low pressure - Steam boilers less than 15 psi. Hot water boilers less than 160 psi and/or F. outlet temperature 5

6 Packaged Boiler Types General Categories Electric Tubeless Firetube Watertube Capacity ,000 MBH 6 11,000 BHP Steam & Hot Water 6

7 The Boiler Package Pressure Vessel Burner Pressure vessel Burner Controls Combustion Controls Burner Management 7

8 Broad Industry Breakdown Commercial Industrial Primarily Low Pressure or Hot Water Comforting Heating Primarily Process Applications with some Comfort Heating 8

9 Commercial Steam & Hot Water Firetube Vertical Tubeless Electric Watertube Cast Iron Copper Fin 9

10 Industrial Steam & Hot Water Firetube Horizontal Vertical Vertical tubeless Electric Watertube Natural Forced Circulation IWT 10

11 Packaged Firetube Details Horizontal Firetube Size range: HP Design pressures: - Steam: # - Water: # Vertical Firetube 11

12 Horizontal Firetube Boilers The Dryback Baffles Tubesheet 4 3 Two (2) Tubesheets Refractory Filled Door

13 Horizontal Firetube Boiler The Wetback Three (3)Tubesheets Three Tubesheets Difficult access, 2 nd pass Water Leg 13

14 Vertical Firetube Boiler Furnace Size range: HP Design Pressures: Steam: 150# Water: 125# Compact Convection Tubes Flue Gas Outlet Shell 14

15 The Watertube Boiler Upper Drum Opposite of Firetube Water in the Tubes Natural and Forced Circulation Large Furnace Upper & Lower Drums or Headers Furnace 15 Lower Drum

16 The Watertube Boiler Size Range: HP Design Pressure: - Steam: 250# - Hot Water: 125# Straight Inclined Riser tubes Bent Hx Down comers Sight port 16

17 The Watertube Boiler Size Range: HP Design Pressure - Steam: 150# - Hot Water: 160# Flextube Stack connection Furnace 17

18 The Watertube Boiler Size Range: HP Design Pressures: - Steam: 170# Requires Forced Circulation Low Water Volume Fast Steamer Water Quality is Critical Forced Circulation Generator 18

19 The Watertube boiler Size Range: HP Design Pressures - Steam: 15# - Hot water: 60-80# Cast Iron 19

20 The Watertube boiler Size Range: HP Design Pressure: - Hot Water: 160# No Steam Requires Circulation Atmospheric Burner or with Fan Assist Copper fin Tube bundle Header 20

21 The Watertube boiler package Size Range: 10, ,000#/HR HP Design Pressure: Steam: to 900# HTHW: +400 Deg. F Natural Circulation Some Forced Circulation IWT D O A A 21

22 Vertical Tubeless boiler 2 Pass Design Size Range: HP Design Pressure: - Steam: # - Hot Water: 160# Multiple Passes (2 4) Furnace Transition Zone Convection Zone 22

23 Electric Boilers Size range: Electrode - Resistance: KW (1 350 BHP) - Electrode: 2 65 MW ( BHP) Design Pressure - Steam: To 250# - Hot water (Resistance) 160# No Emissions on Location High Point of Use Efficiency Resistance NOTE: MW = 1,000,000 watts KW = 1000 watts or 3413 BTU/HR 23

24 Understanding the Load Initial Questions: Total load? Pressure? Cyclicality? Load majority? Steam quality requirement? 24

25 Boiler Choice Firetube? Watertube? 25

26 Cyclicality Spikes in demand? How much add to my normal load? How fast do they occur? Sudden or gradual? Maintaining pressure critical? 26

27 Cyclicality Bent Tube IWT Flextube Sudden swings in load?? 27

28 Burner Choice Sized for optimum firing rate majority of operating time. Normally 4:1 or 10:1 Turndown Burner Turndown 28

29 Purge Losses ENERGY WA$TE 29

30 Load Majority Boiler s Sweet spot 30

31 Boiler Efficiency & Firing Rate 31

32 Burner Choice Percent O 2 12% 10% 8% 6% 4% 2% 0% Typical firing range for many oversized boilers LF 25% 50% Firing Rate 75% 100% Burner Turndown 4 To 1 or 10 to 1 32

33 Burner Choice RULE OF THUMB For every 2% increase in O 2, you lose 1% in efficiency Reference PDF Available: 33

34 Combustion Control Choice Single Point Parallel Positioning 34

35 35 Multiple Boilers

36 36 Central Control Unit

37 Summer boiler Smaller Summer Boiler Complete Skidded Package 37

38 Steam Quality TDS Control 38

39 Steam Quality Three Element Control System Monitoring water level, steam flow and feedwater flow 39

40 Steam Quality Secondary separation with labyrinth or chevron internal separators Steam endures a tortuous path End result is 99.5% dry steam, or < 0.5% moisture to process 40

41 41 Steam Quality

42 Steam Quality Separator 42

43 Summary Boilers constructed per ASME Sections I (HP) & IV (LP & HW) The boiler package consists of pressure vessel, burner & controls (BMS & CCS) Various types of firetubes & watertubes Firetube package 2200 HP and 250# Watertube packages limit at 9000 HP & 900# The watertube boiler is normally superior in handling swing loads Cast Iron boilers are LP & HW only Copper boilers are HW only When considering the total load, look for cyclicality spikes Know where the load is the majority of the time assuring the spikes can be handled within the boilers turndown Know where the boiler s sweet spot is Remember 2% increase in O2 = 1% loss in efficiency Steam quality can be a process issue 43

44 44 Contact Us