Reduce Energy Consumption Through Steam System Modernisation

NHS Sustainable Development: 14th February 2012
‘Reduce Energy Consumption Through Steam System
Modernisation’
Presentation by:
Andy Bennett
National Key Account Manager
1
Overview
Thermal Energy International – Who Are We?
Government Energy Reduction Targets
Why is steam still used in Industry?
Steam system Walkthrough
Key components of the steam system
1. Boiler
2. Steam distribution system
3. Heat exchangers
4. Steam Traps
5. Condensate return system
6. Hotwell
6. Where do these energy losses occur
7. How to fund these improvements
1.
2.
3.
4.
5.
Thermal Energy International
•
Committed to reducing waste energy and reducing consumption
through steam system modernisation
•
Two key product ranges
– GEM Condensate Return Systems
– Flu Ace Flue Gas Condensing Economisers
•
Working closely within a variety of industries with
– Private Sector Organisations
– Public Sector Organisations
Government Targets
Year
Target
2020
34% Reduction
2050
80% Reduction
How Can These Targets Be Achieved?
•
•
•
•
Climate Change ACT
Carbon Budgets
SOGE Targets
CRC Energy Efficiency Scheme – 20,000 large private and public
sector organisations are involved in the CRC Energy Efficiency
Scheme
Source:
www.decc.gov.uk
Best Practice in steam system operation
↑ Efficiency
↑ Productivity
↓ Costs
↓ CO2 Emissions
5
Best Practice in steam system operation
↓ CO2 Emissions
↓ Costs
↑ Efficiency
Productivity
6
Why use steam? More efficient
Available energy
3000
Energy (kj/kg)
2500
2000
Latent
Sensible
1500
1000
500
0
1
5
10
Steam Pressure (bar)
7
20
Why use steam? More practical
• Easy to control –
temperature / pressure
relationship
Variation of temperature with steam
pressure
• Relatively constant
temperature
• High temperatures
• Non toxic
Steam Temperature (ºC)
300
250
200
150
100
50
0
0
• Freely Available
8
10
20
30
40
Steam Pressure (bar)
50
60
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Steam Trap
Hotwell
Condensate
Return
9
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Hotwell
Steam Trap
Condensate
Return
10
Boiler heat losses
Boiler Flue gasses
18%
Steam 75%
Shell
Losses
4%
Fuel
100%
Blow down 3%
11
Boiler economiser
Conventional Economiser
Extract sensible heat from flue gasses
Limited by the dew point temperature
Used for preheating boiler feed water
Typical savings =
2 to 4 %
Condensing Economiser – Heat Recovery
Extract sensible and latent heat
Limited to gas boilers
Lower heat recovery temperature
Typical savings = 15-18 %
12
Condensing Heat Recovery System
Energy Recycling for:
Waste Flue Gas
Sources:
• Process Make-up Water
• Heating
• Institutional &
Industrial Boilers
• Gas Turbine or Engine
Cogen
• Boiler Make-up Water Heating
• Process Liquid Heating
• Dryer Make-up Air Heating
• Combustion Air Heating
• Ventilation Make-up Air
• Heating
• Mixed Air Heating
• Perimeter Radiation Heating
• Domestic Hot Water Heating
15% to 18% Typical Energy Savings
How FLU-ACE® Works
•
Extract Sensible and Latent
Heat
•
The blue area to the right
represents latent heat, the
brown area sensible heat
•
Heated water is circulated at
up to 65°C to various heat
users
•
With indirect design the
primary circuit water can be
raised to 90°C
175 C
150 C
125 C
100 C
75 C
Exhaust Gas Temperature
50 C
Flu Gas Economiser – Case Study
Belfast NHS Trust
Benefits
•
•
•
3 Hospitals Converted
£400,000 + saved annually in
energy
Payback within 12 months.
Flu Gas Economiser – Case Study
St George’s Healthcare NHS Trust
Benefits
•
•
•
•
Recently Converted
Savings of 1.5mW/h,
Circa £330,000 + saved annually in
energy
Payback reduced by 12 months from
original estimate.
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Hotwell
Steam Trap
Condensate
Return
17
Steam Distribution system
Steam mains contain;
• Steam
• Condensate
• Air
• Dirt / debris
18
Dirt pockets
• Every 30-40m (more
frequently on uphill
sections)
• Before a rise
• Before CV’s and
PRV’s
19
Insulation
20
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Hotwell
Steam Trap
Condensate
Return
21
Steam system walk through – Heat
exchangers
22
Plate vs. Shell and Tube heat
exchangers
Plate heat exchangers
+ Improve heat
transfer, compact,
more responsive, no
annual pressure tests
- More susceptible to
leaks, small diameter
flow paths
23
Plate vs. Shell and Tube heat
exchangers
S & T heat exchangers
+ More robust design, can cope with suspended solids,
no leaks
- High surface heat losses, bigger footprint
24
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Hotwell
Steam Trap
Condensate
Return
25
What is a steam trap?
•
Differentiates between steam and condensate
•
Discharges condensate, air and incondensable gasses
•
Retains steam within the system until it has given up its energy
Types of steam trap
• Mechanical
Oversized orifice, opening and closing mechanism
– Float
– TD
– Inverted Bucket
•
•
Orifice plate – Sized orifice, Constant conditions
Venturi orifice – Sized orifice, self regulating over varying loads
Types of mechanical traps
Float Trap
E
A
C
D
B
Types of mechanical traps
Inverted Bucket Trap
Problems with mechanical traps
•
•
•
•
•
Parts, Parts and More Parts
High Failure Rates – Typically 10%
per year
Oversized Orifice, Significant
Failure Path for Steam
Complex Mechanisms, Millions of
Cycles
Live Steam Passes to Operate Trap
by Design
Losses through failed traps
Trap
size
Orifice dia (mm)
DN15
Steam loss kg/hr
6 barg
14 barg
32 barg
3
8
19
43
DN20
5
24
53
119
DN25
7.5
55
121
270
DN40
10
98
214
478
DN50
12.5
152
335
747
No of traps on site
= 150
Average size
= DN20
Steam pressure
= 6 barg
Steam loss/ failed trap = 24 kg/hr
* Reference Spirax Sarco website
Losses through failed traps
Annual steam loss
3,132 tonnes/yr
Steam cost
£20/tonne
Cost of failed traps
£62,640/yr
Plus 476 tonnes CO2 / yr
Equivalent to removing 144 cars off the road!
The GEM Venturi Steam Trap
How Does The GEM Trap Work?
Low Pressure
High Pressure
Steam
Condensate
FLOW
University lab results:
Most efficient over variable loads
2
Float trap
1.8
Free Float
Steam loss (kg hr
-1
)
1.6
TD
1.4
MK
1.2
1
IB
0.8
0.6
0.4
BPT
0.2
GEM
0
0
20
40
60
80
100
120
140
Condensate flow (expressed as flow level in cm of liquid in evaporative column of test rig (cm))
35
160
The Operational Benefits of the GEM trap system
•
•
•
•
•
No moving parts = increased reliability
Energy Savings of 11% +
Permanently Eliminates Live Steam Loss
10 year performance guarantee
Project Payback Typically 12 – 24 months
GEM® Condensate Return System – Case Study
Salisbury District Hospital
Benefits
•
•
•
•
Eradicated steam trap failure
10% Reduction In Steam
Consumption
£40,000 Saved Annually
Project Payback Within 18
months
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Hotwell
Steam Trap
Condensate
Return
39
Condensate return system
Recycles the remaining energy in the condensate
by returning it to the hotwell – 3 main types:
1.
2.
3.
Discharge to drain – total loss of all energy and treated water
Vented return system – reuses condensate and sensible heat
Pressurised return – Reuses the condensate, sensible heat and
flash steam
40
Flash steam recovery check list
Need a low pressure application
– Similar demand profile
– Located close to high pressure system
Flash vessel require insurance inspections
Examples
– Large air heaters
– Boiler feedwater temperature increase
– Space heating systems (seasonal)
41
Steam system walk through
Distribution system
Heat Exchanger
Boiler
Hotwell
Steam Trap
Condensate
Return
42
Steam system walkthrough - Hotwell
43
Energy Losses In A Typical Steam System
18 % stack
losses
3% standing
loss
100% fuel input
10% steam
trap loss
2 % blowdown
loss
55% useful heat output
5% pipework
insulation
loss
5% condensate
loss/flash
2% pipe
leakage
For every £1 spent on fuel you only get 55p of useful energy!!!
TEI can recover
•Steam Traps – 10%
•Stack Loss – 18%
•Flash Steam – 5%
•Boiler Blowdown – 2%
•Insulation – 5%
40%
For every £1 spent on fuel you get 95p of useful energy!!!
How To Fund These
Improvements
Subscription
Subscription is a managed service
paid for out of savings
Immediate savings
Subscription
Includes everything
Use of Equipment
Support
Maintenance
Replacement parts
….it’s all about
SERVICE
Subscription Principles
Subscription puts focus on benefits and
delivers a service capability
Supplier
All-inclusive
subscription
CUSTOMER
Customer
installation
Hardware
Systems
On-going Services
No customer ownership
“ If it appreciates, buy it;
If it depreciates, rent it”
J. Paul Getty
The message is.........
EVERY DAY YOUR MONEY
IS GOING DOWN THE DRAIN
WHEN
The Thermal Energy managed service will cut
your energy cost
and reduce your carbon footprint
WITHOUT INVESTING A PENNY.
Private Finance – Capital Purchase
Example – Capital Purchase
Capital Cost = £100,000
Energy Savings Per Year = £50,000
Project Payback = 2 Years
ON BALANCE SHEET REQUIRES CAPITAL SANCTION. COST NEGATIVE
FOR 2 YEARS
Subscription Example
5 year rental paid quarterly inline with savings = £22,000 per year
Energy Savings Per Year = £50,000
Net Annual Saving = £28,000
•
•
•
•
•
•
OFF BALANCE SHEET OPERATING LEASE
RENTALS OUT OF SAME OPERATING BUDGET THAT ARE MAKING
THE SAVINGS
CASH POSITIVE FROM THE START
NO DEPRECIATING ASSETS
QUICK DECISION
AFTER 5 YEARS HAVE OPTION OF TERMINATING RENTAL,
CONTINUATION AT REDUCED FAIR MARKET VALUE RENTAL , OR CAN
REFRESH THE TECHNOLOGY ON NEW AGREEMENT
Impacting Your Emissions Targets
80%
26-34%
15%
Further reducing up to19% of
overall carbon emissions through
steam system modernisation
NHS Sustainable Development: 14th February 2012
Case Study: Royal National Orthopaedic Hospital,
Stanmore
Presentation by:
Matthew Hardy
General Manager (Estates)
56
GEM® Condensate Return System
Royal National Orthopaedic Hospital, Stanmore
•
Used on RNOH since 1998
•
No trap Maintenance required
•
Energy and Carbon Reduction
•
10 year Guarantee
•
Sized for each application
GEM® Condensate Return System
Royal National Orthopaedic Hospital, Stanmore
Benefits
•
Circa 10% Reduction In Steam
Consumption
•
Circa 10% Reduction In Carbon
Emissions
•
Project Payback Within 18 months
Condensing Heat Recovery System
Royal National Orthopaedic Hospital, Stanmore
•
Recovering waste Heat for Boiler Flues
•
Preheats Boiler Feed water and tops up Hydronic loop
•
Reduces load on Boilers
•
Includes kWh and Carbon metering
Condensing Heat Recovery System
Royal National Orthopaedic Hospital, Stanmore
Benefits
•
578 Tonne Reduction In Carbon
Emissions Per Year
•
£68,929 Saved Annually
•
Looking at extending heat use for
further savings
Any Questions?
Stand 16: The Brewery
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