thermal energy metering technology - airah...•volume flow rates under en1434 specified in m3/hr q...
TRANSCRIPT
Thermal Energy Metering Technology
Presented by Aquip Systems Pty Ltd
P R E S E N TAT I O N H E A D I N G Training presentation by <INSERT NAME?V 1 - 1 8
• Instrumentation and technology company started 1991
•Offices in NSW and WA
•26 years experience in flow metering for liquids and gasses
•9 years in thermal energy metering
Brent Ladbrook
With Aquip since 2010 and With Aquip NSW since 2016
0 1
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Aquip Systems
•Learning Outcomes
• Industry Trends
•Terminology
•Standards
•Meter types
•Considerations for selection
•There is a test at the completion of the course so please pay attention and ask questions as we go
0 2
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Session Overview
•Understand the fundamentals of thermal metering
•Be able to select the best thermal metering options for an
application
•Understand the fundamentals of communication protocols
•Understand basic installation principles
•Understand that system accuracy is more important than
component accuracy
0 3
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Learning Outcomes
0 4
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Industry Trends
Trends
Increased Costs
Costs are often 50%
Increased metering
NBH has 199
meters
Cost Recovery
Increased Profit $$
0 5
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Terminology
•Flow Rate - Instantaneous amount e.g. m3/hr, l/s, kW
•Totaliser – Accumulates total for period e.g. m3, litres, kW.h
•Velocity – Speed of fluid through pipe e.g. m/s
•Zero Cut off – Value below what the meter can accurately read
and therefore reports zero
•Turndown ratio – Ratio between permanent flow and minimum
guaranteed accuracy or the measurement range
•Accuracy – How close to the real number is the reading
•Repeatability – how regularly does the meter report the same
number
•MPE – Maximum Permissible Error
0 6
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Standards
•There are NO Australian standards
•NMI is not currently possible and commonly EN1434 is
referenced
•Three main classes of Meters under EN1434
•Class 2 is the best commercially available
•Calibration certificates do not mean type approval to
EN1434
•Other standards include OIML and MID
0 7
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
What is a Thermal Energy Meter
0 8
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
What is a “Thermal Energy Meter”• Volume flow rates under EN1434 specified in m3/hr
qi - lower limit of the flow rate
This is usually 1/100 of qp (Expressed
as a turndown ratio of 100:1
)
qp - permanent flow rate
qs - upper limit of the flow rate (<1h/day , <200h
/year)
This is usually 2 x qp
The sensor will not read below Zero Cut off, or
above the saturation points.
This an example of a DN100 qp 100 and will vary from
model to model
0 9
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
What is a “Thermal Energy Meter”
Flow Sensors should be sized to flow rate NOT pipe
size
• min, max and permanent flow rate should be
considered
• Pressure loss should be considered
• Pressure class should be considered PN16 and PN25
are common
• Meter should be no more than one standard size below
the pipe size (this is for flow dynamics reasons)
1 0
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
What is a “Thermal Energy Meter”
Typical Accuracy Curve showing that
meters are less accurate at lower flow rates
MPE under EN1434-1
EMPE = 𝐸𝑐2 + 𝐸𝑡
2 + 𝐸𝑓2
1 1
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8 Types
•Types of Meters
•Heat meters
•Cooling
•Heating and cooling
•Physical sizes are standarised
•Threaded end: G¾” through to G2”
•Flanged (DN): DN15 through to DN250
•Above DN250 there are no standard sizes
•From a cost perspective threaded brass meters are
typically lower but not available above qp 10m3/h above
this a flanged meter must be used.
1 2
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Measuring Thermal Energy•Simplified heat transmission formula is:
•Energy = V x ∆Θ x k
•Where V= water volume in m3
•∆Θ = the measured temperature difference
•k = the heat coefficient of water, calculated according to
the formula of EN 1434
•Heat Meter with flow meter located in return (supply =
70°c Return = 30°c , Flow = 1 m3)
Energy = V x ∆Θ x k
≃ 1 x (70 – 30) x 1.1561
≃ 46.27 kW
If the Flowmeter is in the supply then
≃ 45.44 kW
1 3
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Flow Metering Components
•Many types of flow sensors are available however
commonly used types are either mechanical or electronic
•Mechanical types include Turbine meters and Paddle
Wheel sensors
1 4
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Mechanical Flow SensorsChallenges:
• Corrosion, erosion, scaling
• Fouling
• Incorrect installation – particularly paddle wheel
• Poor turndown ratios
• No diagnostics at all
Benefits:
•Typically low purchase price
•Paddle wheels seem easy to install but
beware of flow profile
1 5
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Electronic Flow Sensors
•Electronic types include Ultrasonic and Electromagnetic
(Mag) sensors
•They are solid state and have no moving parts
•Mag type are always “inline”
•Ultrasonic can be “inline” or “clamp-on” type
1 6
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
The Principles of Electromagnetic Flow Sensors
1 7
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Electromagnetic Sensors
Challenges:
•Corrosion, erosion, scaling particularly on electrodes
• Installation issues
•Turndown ratios
•Few diagnostics
Applications
•Often used for water metering and often the best inline solution
above DN300
Benefits:
•Typically low purchase price
•Readily available
1 9
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Inline Ultrasonic Sensor
Challenges:
•Minor effect corrosion, erosion, scaling
Applications:
• Pipes up to DN300 and flows up to
1000m3/h
Benefits:
•Typically low purchase price
•Usually good diagnostics
•Readily available
•Turndown ratios typically 100:1 or better
2 0
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
“Clamp-on” Ultrasonic SensorChallenges:
•Minor effect of scale build up
•Higher purchase price
Applications:
• Large pipes or pipes where stopping the
flow is not desirable e.g. Data Centres
Benefits:
•Sized by pipe and not flow 10mm –
6500mm
•Wide dynamic range 0.01 – 25 m/s
•Easy installation – No Shutdown required
•Excellent diagnostics
2 1
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Electronic Flow Sensors
•Other types exist including
•Differential Pressure
•Vortex
•These are seldom used
2 2
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Temperature Sensors
•PT100, PT500 and PT1000
•PT stands for platinum and the number is the measured
resistance of the probe at 0˚C in ohms
•2 wire and 4 wire configurations – 4 wire is not affected by
distance
•Temperature measurement is VITAL to good energy
measurement
Accuracy
•Class A : dT = ± (0.15 + 0.002 × T) (-200 ... +650 °C)
•Class B : dT = ± (0.30 + 0.005 × T) (-200 ... +850 °C)
•Class AA : dT = ± 1/3 (0.30 + 0.005 × T) ( 0 ... +150 °C)
2 3
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Temperature Sensors - Insertion
2 4
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Thermal Calculators
•Typically will power flow part and temperature
sensors
•Will calculate and record energy, together with
other variables
• Instantaneous and totalised for some values
•Energy Flow
•Liquid Flow
•Temperature on both sensors
•Meter information
•Error codes
•Diagnostics
•Historical data
2 5
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Thermal Calculators
•Must be programmed to be on inlet or
outlet side of the measured area
dependent on where flow part is installed
as the heat coefficient is different on each
side
•Thermal calculators all have a potential
error and must be set up precisely for the
flow and temperature parts of the meter
•Some will store up to:
•1400 hours
•460 days
•36 months
•15 years
2 6
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Communications•Pulse
•Analogue (4-20mA)
•Pulse is not recommended as limited
information can be sent, pulses can get
lost, distance and scaling are issues
•Analogue is not ideal as limited information
can be sent, distance and scaling are
issues
2 7
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Communications•High Level Interface (HLI) such as:
•BACnet
•Modbus
•M-Bus (Meter Bus)
2 8
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Installation Considerations
•Site access
• Lifting considerations for larger meters
•New Pipes
•Typically inline sensors on smaller pipes
and “clamp on” could be considered on
larger pipes. This will depend of the use
of the data i.e. billing
•Allow straight lengths free from valves
and fittings
2 9
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Installation Considerations
•Existing Pipes
•What is the real cost of installation
including loss of flow?
• Is the qp known?
•What are the unknown risks?
• Is my design such that I can tolerate a
pressure loss
•Check back pressure requirements for
inline meters
•Clamp on is often an ideal solution and
can be used for temporary measurement
or establishment of qp
3 0
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Installation Considerations•Power supply
•24VAC, 240VAC, 24VDC, Battery
• Ideally have 10 straight pipe diameters
upstream and 5 downstream
•This is not always possible and
• Immediately downstream from valves is
the least favoured position
•Check the manufacturers manual
•Pressure loss
•All inline meters will have some pressure
loss
3 1
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Installation Considerations•System accuracy vs component
accuracy
•For integrated meters, NABERS requires
better than 5% accuracy across full
sensing range
•Green Building Council of Australia refer
to NABERS
•Watch out for “Frankenstein”
•Check Ingress Protection (IP) rating
•Check Zero Flow Calibration (for clamp on)
•Check maintenance recommendations
•Pressure Requirements
•Check Protocols ie. Modbus RTU / TCIP
•NABERS National Australian Built Environment Rating System
3 2
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Installation Considerations – Cost of getting it wrong
• Integration difficulties
•Missing low flows means missed revenue
•Selection and installation errors subtract
from published accuracy of meter
•Maintenance costs and recommissioning
•Small percentages can add up to a lot of
money over time
3 3
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Installation Considerations – Cost of getting it wrong
•Sum for period is 855 kWh / 10 hours
•DN100 pipe on a Boiler
3 4
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Commissioning•Meters can be “validated” using a “Master” portable
clamp on ultrasonic thermal meter
•The more diagnostics that you have the more you know
about the performance of your meters
•Many meters will have error codes that are
downloadable
•Data transmission should be validated to show that the
output from the meter received and interpreted
correctly
3 5
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Maintenance
•NABERS reference a ten year period but this relates
more to the reading system than meter accuracy
•Green Building Council of Australia reference NABERS
or “a recognised standard”
•Meters can be “validated” using a “Master” portable
clamp on ultrasonic thermal meter
•Under EN1434 10% percent of meters are checked
every 6 years and all meters replaced if meters have
drifted too far
• If you are a building owner these meters may be your
“cash registers”
3 6
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8 Case Study – Clamp on
•Major hospital - flow
interruptions are
impossible pipe was
existing
•Large pipe - high cost of
flanged meter and
installation
• Insulation easily replaced
•Allocation metering
3 7
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8 Case Study – Paddle Wheel
•Flow only in a chiller plant
•Used for monitoring flow
rates and adjusting VSD
•0-10VDC output to the BMS
•Not used for billing
•Bi directional flow on some
meters
•Meters were commissioned
and validated with a portable
clamp on ultrasonic meter
3 8
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8 Case Study – EN1434 Billing Meters
•A Sydney hotel has a third party chiller and boiler installed on site and purchase chilled and heated water from the owner of the chiller/boiler
• Inline ultrasonic sensors were selected as they are certified to EN1434 and the meters are used for billing
3 9
P R E S E N TAT I O N H E A D I N G
Thermal Energy Metering
V 1 - 1 8
Questions
Brent Ladbrook
u
+61 448 955 515