Presented by Steve Connor August 26, 2015 Boiler Choices: The What, When & Why
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
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
Typical Applications Strictly process? Strictly heating? Separate Process & Heating? Single Split System? 4
Split System Steam Regulating Valve Plate & Frame Shell & Tube 5
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
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
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
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
Design Pressure Limitation Modular, FT Cast Iron Firebox Tubeless Vertical FT 10 Modular, Copper
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
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
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
Burners Multiple fuel & straight gas firing Multiple fuel firing Gas firing 14
Fuel Vertical FT Modular HW Finned tube Flextube 15
16 Hydronic Heating
Considerations Hydronic Heating Vertical hot water boiler Modular Flextube Firetube Non-condensing 17
Hydronic Heating High Pressure steam High Temperature Hot Water (HTHW) only 18
Considerations Hydronic Heating Vertical hot water boiler Modular Flextube Firetube Non-Condensing 19
Primary-Secondary with Bypass Line & Blend Valve Flexible designed boilers Primary (Red) Blend valve Secondary (Blue) 20
Considerations Hydronic Heating Condensing Modular 21
Considerations Condensing Applications Condensing Hot Water 125 psig design Return temps of 130 o F or less Provides highest efficiency 22
Impact of Higher Inlet Temperature On Efficiency 23 23
Inverse Efficiency Curve on Condensing Boilers 24
Considerations Hydronic Heating High mass boiler will cost more, but there are key advantages too Low Mass High Mass 25
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
Variable Flow Primary Hydronic piping system arrangements High Mass Boilers 120F 160F 210gpm Primary only 70gpm 70gpm 70gpm 210gpm 120F 120F 120F 120F 27
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
Considerations Process Constant? Swing/Surge? Brief draw? 29
The selections: IWT (D) IWT (A) Considerations Process IWT (O) Steam Generator Vertical FT Horizontal FT 30
Constant Load: Considerations Process IWT (D) IWT (A) IWT (O) Steam Generator Vertical FT Horizontal FT 31
Swing Load: Considerations Process IWT (D) IWT (A) IWT (O) Steam Generator 32
Steam Quality. High quality steam, <1/2% moisture Drum internals 33
Super Heat Saturated Steam 600 Psig, 485 0 F. Add 300 0 F of SH Inlet Superheated Steam 785 0 F. for process Outlet 34
Steady Load, Brief Draw: Considerations Process IWT (D) IWT (A) IWT (O) Steam Generator Vertical FT Horizontal FT 35
Considerations Process Brief Draw 36
Considerations Process Steam space 37
Improving Efficiency by understanding the load Where will the boiler spend most of its time? 38
Two Ways to Lose Efficiency Cycling: Pre and post Purge losses Low combustion efficiency when firing @ 50% or less. 39
Pre & Post Purge losses Hey, I m cycling too much! BTU s out the stack 40
Varying Plant Load Turndown & Lead Lag Control Low fire Medium Fire High fire 41
Low Combustion Efficiency Here s where I spend most of my day!? Low to Mid fire 42
Excess Air Increases As The Firing Rate Decreases Sweet spot 43
As Excess Air Increases, Efficiency Decreases Lose 1% in Efficiency For every 2% increase in O2 44
Combustion Control Single Point Positioning Hysteresis Slip and stretch Wear Non-repeatable 45
Combustion Control Parallel Positioning Separate fuel settings Precise control Eliminates slip and stretch Repeatable Gas Air Oil 46
47 Summer Boilers
48 Space & Weight
Space & Weight Advantage Watertube Smaller footprint Less weight Greater height 49
Advancing Firetube Designs 50
Space Reduction Advanced Heat Transfer Tube 51
52 Space & Weight
Emissions NOx is major concern Precursor to Smog 53
Emission Control Lo-NOx burner SCR FGR 54
55 Price Advantage
Price Advantage Advantage Firetube! 56
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
Today s recording can be found at www.cleaverbrooks.com/webinars.com 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 www.cleaverbrooks.com/webinars. CONTACT US David Brick Product Manager Firetube Boilers dbrick@cleaverbrooks.com 414.577.2736 58