Presented by Steve Connor August 26, Boiler Choices: The What, When & Why

Transcription

1 Presented by Steve Connor August 26, 2015 Boiler Choices: The What, When & Why

2 What We Are Covering Today Commercial/industrial market applications. Steam & hot water boiler types. Application decision points. Process load matching. Emission considerations. Space, weight and price considerations with process boilers Summary & QA 2

3 Typical Industries Served Refinery & Petro-Chemical Universities/Colleges/Schools Government buildings Hospitals Hotels and Conference Centers Chemical/Pharmaceutical Automotive Food & Beverage Textiles Corrugated container Pulp & paper Building supplies Ethanol & Bio-Diesel Aerospace & Military 3

4 Typical Applications Strictly process? Strictly heating? Separate Process & Heating? Single Split System? 4

5 Split System Steam Regulating Valve Plate & Frame Shell & Tube 5

6 Firetube Watertube Firetube, multi-pass Small O type IWT Firetube, 2 pass Firebox Modular, Condensing/non-condensing Flextube Copper, Low mass Vertical Firetube Vertical, tubeless Modular, condensing/non-condensing Cast iron Steam generator

7 Considerations Pressure/Temperature Section IV Low pressure steam, up to 15# & up to 160# HW and 250 Deg. F max. Section I Over 15# steam & 160# HW and over 250 Deg. F 7

8 Considerations Boiler Capacity & Pressure Firetube, Horizontal Firetube, Vertical Flexible Watertube Vertical steam generators Vertical steam & hot water Modular Boilers Industrial Watertube Boilers Electric/Electrode (on top) APPLICATION Up to 20,000 PPH of steam (20 MMBTU Hot Water) Design Pressures up to 150# Steam, 160 # HW 8

9 Considerations Boiler Capacity & Pressure Firetube, horizontal Flexible Watertube Vertical steam generators Industrial Watertube Boilers Electric/Electrode APPLICATION Up to 20,000 pph of steam (20 MMBTU Hot Water) Design Pressures up to 300 PSIG 9

10 Design Pressure Limitation Modular, FT Cast Iron Firebox Tubeless Vertical FT 10 Modular, Copper

11 Considerations Boiler Capacity & Pressure APPLICATION Firetube, horizontal Industrial Watertube Boilers Electric/Electrode Up to 70,000 pph of steam (70 MMBTU Hot Water) Design Pressures up to 300 PSIG 11

12 Considerations Boiler Capacity & Pressure APPLICATION Industrial Watertube Boilers Electrode Over 70,000 pph of steam (70 MMBTU Hot Water) Design Pressures exceeding 300 PSIG or superheat 12

13 Considerations Fuel Vertical steam generators Firetube, horizontal Industrial Watertube Boilers Type of Fuel: Gas #2 oil #6 oil Bio Steam Generator Horizontal Firetube IWT 13

14 Burners Multiple fuel & straight gas firing Multiple fuel firing Gas firing 14

15 Fuel Vertical FT Modular HW Finned tube Flextube 15

16 16 Hydronic Heating

17 Considerations Hydronic Heating Vertical hot water boiler Modular Flextube Firetube Non-condensing 17

18 Hydronic Heating High Pressure steam High Temperature Hot Water (HTHW) only 18

19 Considerations Hydronic Heating Vertical hot water boiler Modular Flextube Firetube Non-Condensing 19

20 Primary-Secondary with Bypass Line & Blend Valve Flexible designed boilers Primary (Red) Blend valve Secondary (Blue) 20

21 Considerations Hydronic Heating Condensing Modular 21

22 Considerations Condensing Applications Condensing Hot Water 125 psig design Return temps of 130 o F or less Provides highest efficiency 22

23 Impact of Higher Inlet Temperature On Efficiency 23 23

24 Inverse Efficiency Curve on Condensing Boilers 24

25 Considerations Hydronic Heating High mass boiler will cost more, but there are key advantages too Low Mass High Mass 25

26 Secondary Primary/Secondary Low Mass Boilers 120F 160F System pumps 210gpm Boiler pumps De-coupler 300gpm 90 gpm 100gpm 100gpm 100gpm 210gpm 120F 130F 130F 130F Primary 26

27 Variable Flow Primary Hydronic piping system arrangements High Mass Boilers 120F 160F 210gpm Primary only 70gpm 70gpm 70gpm 210gpm 120F 120F 120F 120F 27

28 Primary-Secondary w/ low Mass boilers System Comparison Variable Flow Primary w/ High Mass Boilers BENEFITS of Variable Flow Primary: Boiler pump elimination Saves electrical energy Piping system simplicity Saves install cost Saves fuel cost 28

29 Considerations Process Constant? Swing/Surge? Brief draw? 29

30 The selections: IWT (D) IWT (A) Considerations Process IWT (O) Steam Generator Vertical FT Horizontal FT 30

31 Constant Load: Considerations Process IWT (D) IWT (A) IWT (O) Steam Generator Vertical FT Horizontal FT 31

32 Swing Load: Considerations Process IWT (D) IWT (A) IWT (O) Steam Generator 32

33 Steam Quality. High quality steam, <1/2% moisture Drum internals 33

34 Super Heat Saturated Steam 600 Psig, F. Add F of SH Inlet Superheated Steam F. for process Outlet 34

35 Steady Load, Brief Draw: Considerations Process IWT (D) IWT (A) IWT (O) Steam Generator Vertical FT Horizontal FT 35

36 Considerations Process Brief Draw 36

37 Considerations Process Steam space 37

38 Improving Efficiency by understanding the load Where will the boiler spend most of its time? 38

39 Two Ways to Lose Efficiency Cycling: Pre and post Purge losses Low combustion efficiency when 50% or less. 39

40 Pre & Post Purge losses Hey, I m cycling too much! BTU s out the stack 40

41 Varying Plant Load Turndown & Lead Lag Control Low fire Medium Fire High fire 41

42 Low Combustion Efficiency Here s where I spend most of my day!? Low to Mid fire 42

43 Excess Air Increases As The Firing Rate Decreases Sweet spot 43

44 As Excess Air Increases, Efficiency Decreases Lose 1% in Efficiency For every 2% increase in O2 44

45 Combustion Control Single Point Positioning Hysteresis Slip and stretch Wear Non-repeatable 45

46 Combustion Control Parallel Positioning Separate fuel settings Precise control Eliminates slip and stretch Repeatable Gas Air Oil 46

47 47 Summer Boilers

48 48 Space & Weight

49 Space & Weight Advantage Watertube Smaller footprint Less weight Greater height 49

50 Advancing Firetube Designs 50

51 Space Reduction Advanced Heat Transfer Tube 51

52 52 Space & Weight

53 Emissions NOx is major concern Precursor to Smog 53

54 Emission Control Lo-NOx burner SCR FGR 54

55 55 Price Advantage

56 Price Advantage Advantage Firetube! 56

57 Final Summary There are any number of boiler types to fit an array of applications. Selecting the right one is a matter of capacity, pressure, system requirements, fuel, space, weight and price considerations. The IWT is excellent for large swing loads because of its quick recovery. Comparing apples to apples, the IWT is smaller and lighter than a FT. The FT is less expensive than the IWT. The firetube is excellent for steady load, brief draw of steam. With hydronic heating applications distinguish between low mass and high mass boilers. High mass boilers can be applied to variable flow primary systems, low mass cannot. HW boilers won t condense above 130 deg. F return temp. With condensing boilers, the lower the firing rate, the higher the efficiency. Select boilers based on knowledge of the load because all boilers have a sweet spot; operating here most of the time saves energy A summer boiler should be strongly considered if max. load is seasonal. 57

58 Today s recording can be found at Q&A SESSION Request Certificates of Completion at webinars@cleaverbrooks.com All questions will be answered either directly, or posted in the collective response Q & A document located at CONTACT US David Brick Product Manager Firetube Boilers dbrick@cleaverbrooks.com