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PERFORMANCE INSPECTIONS WITH INNOVATIVE ANALYSING EQUIPMENT
RESULTS IN
SIGNIFICANT ENERGY SAVINGS
IN
AIR-CONDITIONING AND REFRIGERATION SYSTEMS
Klas Berglöf
ClimaCheck Sweden AB, Sweden
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Founded 2004 (method developed 1986)
Fast growing tripled turnover since 2009
More than 600 systems on the market
80% export
distributors in 15 Countries
5 markets dominating sales
UK, Italy, Spain, Sweden, Germany
Started introduction
Canada, USA and Australia
ClimaCheck Sweden AB
www.climacheck.com
ClimaCheck Sweden
Stockholm head office staff
Four engineers, one technician
Jönköping two engineers
ClimaCheck getting International acceptance
• Refrigeration Product of the Year 2009 in UK
• Member of Cleantech inn Sweden 2010
• World Wildlife Fund Climate Solver 2011
• In standardisation groups ASHRAE, Germany and UK
• Cooperation with 20+ universities and research institutes around
the world
• Awarded funding from Swedish Energy Agency Feb 2012
– 120 000 Euro - partner SP (=Swedish TÜV) develop guidelines/methods for SEI
• Awarded 203 000Euro Funding in EU Cool-Save project Feb 2012
– 1.3 million Euro total project (Efficiency in Food processing industry)
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Update - performance analysing
• Performance analysing – optimisation in HVAC in focus globally
• Standardisation Code of practice work in progress in many
markets
– UK – IOR – SEI “System Efficiency Index” under implementation
• ClimaCheck has standard system template incorporating SEI
– Germany – VDMA No. 24247 “Energy efficiency of cooling systems”
• ClimaCheck has standard system template incorporating VDMA 24247
– Sweden – Minimum requirement for Energy optimisation for HVAC
Logging and analysing equipment type ClimaCheck or equivalent
– USA – ASHRAE FDD SPC 207P “Fault Detection and Diagnosis”
ClimaCheck participate in standardisation workgroup
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ClimaCheck opens the ”Black Box” that often use 40-60% of a buildings electrical energy
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Establish base line – identify optimisation potential
Typical savings 10-40% from low cost measures
If there are compressors we are interested
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ClimaCheck Sweden AB Klas Berglöf
www.climacheck.com
Fixed installation Field inspection unit
Knowledge = enhance performance
save energy and environment
“If you cannot measure you cannot control it.”
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15-20% of all electricity used for refrigeration, air-conditioning and heat pumps
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13% of 164 systems were OK!
These were mainly commissioning or warranty inspections
planned and contractor had the chance to check
Huge difference between theory and practice!
Representation of faults for all the sectors
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78
4
2720
0102030405060708090
Com
press
or
Exp
ansio
n va
lve
Char
ge
Cont
rol s
yste
m
Sec
ondar
y flo
w
No fa
ults
Num
ber
of
syste
ms
Source: Master Thesis by John Arul Mike Prakash, , KTH Stockholm 2006
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Huge variation in COP
% Variation in COP (vs.) Nominal capacity kW
-40
-30
-20
-10
0
10
0 200 400 600 800 1000
Nominal capacity kW
% variatio
n in
CO
P
Source: Master Thesis by John Arul Mike Prakash, , KTH Stockholm 2006
Optimisation often saves
20-40% at minimal investment
Failure rate and cost
reduced
Carbon footprint higher than it should be
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Current situation and trend
• Equipment owner satisfied if temperature is achieved
• No requirement on documentation of performance
• Technicians-consultants have no chance to learn if they do not
have a customer requirement to do things.
• EU directive require “Performance Inspections” on all AC-
systems above 12 kW calculated to require 15 000 inspectors.
• Energy cost is increasing
• Environmental awareness - certifications
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Who is to blame?
• Equipment owners
– Buy on price and full-load performance
– Rarely validate actual operating performance
– Treat maintenance as a low cost commodity
• Manufacturer
– Supply what customers ask/pay for
– Servicemanuals lack most of relevant service
information
• Superheat, subcool, dT condenser/evaporator to air/water
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Who is to blame 2?
• Installers
– Do what customers pay them for
– Have no responsibility except warranty
– If nobody pay for optimisation it can not be supplied
• Service contractors
– Do what customers pay them for
– Difficult to make money on maintenance under competition
– Moneymaker is the failures – no price pressure
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Who is to blame 3?
• Universities and training institutes
Do not train researchers, engineers and
technicians that understand/focus on
operation of dynamic systems in real
applications
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Why the current situation?
• It has been considered to costly to measure cooling processes
in the field.
• Conventional method often raise more questions than it gives
answers.
• Equipment owners do not understand technology
• Purchasing process of buildings
• Owners short time perspective – buildings are built to be sold
• Commissioning procedures are mostly only “function test”
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Measuring and analysing the refrigeration cycle
• Analysing the refrigeration process offers:
– A cost-effective way to define actual performance
– A possibility to pin-point and quantify deviation
– Input to do cost/benefit estimates of improvements versus
replacements
– Change of focus from low cost maintenance to energy
optimisation
Upgrade of service industry
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When do you need Performance?
Commissioning – ensure spec. - minimize warranty cost
Performance inspection – optimisation
Continuous monitoring – early warning and optimisation
Preventive maintenance – reduce failure rate – optimise
Trouble shooting - FDD – avoid damage to product
Decision support – expansion – retrofit ?
Any expert - independent or from supplier can analyse system
Almost always needed!
visualisation of performance and function of each component
Also used by 40+ manufacturer development and production test rigs
Do not retrofit without knowing what you retrofit!
R-22 Retrofit Pre-retrofit analyses
Do not invest in poor systems that are failing
Post-retrofit analyses ClimaCheck optimisation
Fixed system Establish baseline
consumption
Optimise Document performance Detect future deviation
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Method is well proven
• Experience since 1986 when it was patented
• Method –evaluated - validated 1989 by SP – Technical Research Institute of Sweden
• 600 field measurement systems in use
• Used by 50 manufacturers of heat pumps, dehumidifiers, refrigeration and air conditioning equipment – Development laboratories
– Product control in production
– Commissioning, trouble shouting, warranty inspections and aftermarket
• Method used in research and education – Universities in Sweden, German, Spain, Italy, UK, US and several
“trade training institute”
Global references in all sectors
• Carrier Europe for Chiller optimisation performance inspections
– Use portable Performance Analysers in all EU countries for Inspections and trouble shooting.
• Supermarkets Sweden, UK, large project in Carrefour, Metro in Italy
– Saved 20-30% in pilot on 6 hypermarkets 2010 - now installed in 70+.
• Johnson Control industrial contractor in Spain/Sweden/UK
– Correct problems and improve efficiency in large industrial ammonia plants
• AC and heat pumps with leading companies such as i.e. Danfoss heat pumps
• Copeland Europe compressor manufacturers
– Use ClimaCheck in trouble shooting and development work with their customers
• DuPont and Solway refrigerant manufacturers
– Use ClimaCheck to document retrofit projects
• Several projects on-going in US, Australia, Middle East and India
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Easy to apply – to standard service “points”
2 pressures from service ports
Electrical input
7 surface temperatures
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Application of sensors to standard system (typically done in 20-30 minutes)
• 2 pressures
• 7 temperatures
• 1 power input
No information about system or compressor added
Simple Refrigeration Cycle
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P
h
m Vaporization
Expansion
condensation
compression
m
m m
m
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Analyzes on the “standard” process
Enthalpy
1. Low pressure and
suction temp.
2. High Pressure and
discharge Temp.
3. High pressure and
liquid temperature.
Mass Flow = (Power consumption – heat losses) / Enthalpy Increase
COP = Cooling Capacity / Power Energy Consumption
P LP
P HP
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2 3
Ideal Compression
Cooling Capacity
Power Energy
Consumption
Heat Capacity
Enthalpy
Difference
Pressure
Use the Theory for practical use on field
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Theory Performance analysing using ”Black Box” perspective on compressor
Enthalpy increase refrigerant
Electric energy input
Heat losses
(relatively small and predictable)
(e.g. Electric input = enthalpy increase + heat losses from shell)
What about error in the heat loss estimate?
33kW
Conditions
+5/50°C R407C
T = +15°C
T = 85°C
Heat Loss Enthalpy Mass Flow Capacity
% Increase Rate kg/s kW
5 48.5 0.653 100
7 48.5 0.641 98.2
40% error in the Heat Loss results in <2% Capacity Error
Limitations
• If ”heat loss” from compressor can not be
modelled
– Oil-cooling normally easy to model
– Water-cooling is normally easy
– Air-cooling is normally easy
– Liquid injection can be a challenge
Remember that 99% of systems have no cooling
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Key Results
• Cooling capacity (± 7% accuracy) • Heating capacity (± 7% accuracy) • COP (± 5% accuracy) • Compressor efficiency • Super heat and sub cooling • Functionality of Control
• Evaporation, Condenser pressure and temperature • UA and mean temperature differences in evaporator and
condenser • Flow of secondary systems based on Capacity and temp.
difference
Listed are only key information – standard template consist of
> 40 outputs allowing detailed analyses of each component
Un-biased information on performance
1. The only input that is not a measured value is the heat
losses from the shell.
2. No manufacturer data as input
3. Documentation can be checked and evaluated by any
competent person
4. All components can be checked versus manufacturers data
Challenge is to build competence in industry
Awareness among users
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Report from Carrier site inspection
Rapport från mätning
Anläggning:
Datum: 20100426
Tidpunkt start: 11:57
Tidpunkt stopp: 13:17
Title
Measured
Value
Nominal
Data Deviation
COOL_EWT 9.5 °C 9.5 0.00 K
COOL_LWR 5.7 °C 5.7 0.00 K
COND_EWT 35.6 °C 35.6 0.00 K
COND_LWT 45.1 °C 45.1 0.00 K
POWER KW 350.2 kW 342.0 8.20 kW
COOLING CAPACITY 1177.4 kW 1160.0 17.40 kW
EER 3.36 3.39 0.03
HEATING CAPACITY 1503.2 kW 1484.0 19.20 kW
COP 4.29 4.41 0.12
Measurement made by:
Carrier Performance Analyser
ap 1.3 % positiv deviation
Stefan Orwén, Carrier AB, Malmö
TrioPlast, Landskrona KM11
Nominal data is the values we get from running E Cat with actual values from the measurement.
ap 2,8 % negativ deviation
Comment
ap 2,3 % negativ deviation
ap 1.5 % positiv deviation
Site:
Un-biased validation of
Performance – no Carrier inputs
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Same method for complex systems Dairy with 3 oil-cooled screw chillers
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CO2 cascade system with R134a
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Documentation of performance
and component by component evaluation
20 minutes to connect
(for a complex industrial plant it might be a few hours)
Size is not important
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Two stage centrifugal
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Presentation of data is key for analyses
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Start-up Part load Full load
Comp. eff
Start-up
Part load Full load
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COP +10% at full load
Compressor eff. 48% to 64% When part to
full load
Super heat. 0.8 K at part load -critical
8 compressors no need for part load > saving more than 5000 Euro
100%
67%
Temp. diff. 9.3 K
Secondary out – evaporation
Good ≈ 3-5 K
Temp. diff. 9.3 K
secondary out – condensing Good ≈ 1-4 K
Superheat affected by frost build-up
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on-line monitoring
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Fixed installation with web access
Energy monitoring - statistics
Early Warning
Hourly energy/cost statistics for owners
• Energy statistics - cost
• Monitor kWh and USD per hour
• Documents “energy profile” versus ambient temperatures
• Compare consumption with “energy profile”
• Document energy optimisation projects
• Benchmark different plant
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Energy Statistics
as optimisation
tool
Visualisation of optimisation June 14th
Green line is 12 month average kWh at daily ambient
Red line average daily temp
Auto-diagnostics to follow many plants
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Status of 27 roof top units on public office building
in Portland, Oregon - Oct 2011
Red = outside spec
Water chiller on naval ship in Texas
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Screw chiller with oil cooler
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Stable operation
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Performance of Screw chiller
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Low on charge
and large variation of flow
dependent on which pumps that were in operation
What was outside specification
• Charge - over and under charge
• Superheat setting - high and low
• Hunting valves - distribution
• Compressor efficiency - low
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Italian Supermarket in Milano saving corresponds to 16 000 Euro per year
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Drift som
tidigare
Adj.
controls
27% higher
COP
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Compressor Pack in Supermarket
Comp 2 Low Efficiency
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Comp 2 Low Efficiency
Average Comp. Efficiency
Compressor Pack in Supermarket Comp 2 Low Efficiency
Comp. Eff. 1, 3 and 4
Full load Full load Full load
Stab. Stab. Stab.
Optimisation project in 6 Carrefour hyper/supermarkets in Italy
Total saving 23% aprox. 318 000 Euro (416 000 USD)
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Data supplied
by contractor Scar
and
Carrefour Italy
for 7 month
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Optimisation measures
• Systematic work with optimisation is the prerequisite for savings
– Optimise evaporation
• Common with lower settings than required/design due to hysteresis in step control
• Frequently a problem in a display case is fixed by lowering set-point (never
readjusted even if problem fixed)
– Optimise condensing
• Define minimum allowed condensing for safe operation
• Detect fouling when it occurs – dust, leaves, seeds +++
– Optimise controls
• Short cycling should be reduced as much as possible – no urgency
• Cycling of fans > changes in sub cooling > flash gas > fluctuations in evaporation > cycling
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Optimisation measures cont.
• Correct under/over-charged systems
• Fix compressors with decreased efficiency
• Poorly insulated suction lines
• Poorly functional refrigeration economisers
• Poorly functional expansion valves
With instant feedback optimisation become dynamic
contractors and equipment owners can calculate cost - savings
Experience of 25 years of optimisation work
• Few system run as intended
• Multiple faults are more the rule than exemption
• Lack of information of design operation is a challenge
• Many times symptoms are addressed not the cause
• Lack of awareness of importance of proper service
• Social competence is more important than technical
• Learning curve is rapid when focus change
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Systems Efficiency Index New performance factor
• Overcome draw back of existing indicators
– COP/EER/SEER/Cooling load
• are totally dependent on rating conditions
• Sensitive for changes in flow
– Seasonal Performance factors
• Costly to get right
• Sensitive to Climate and use of building/plant
• Not suitable for benchmarking
• No info on what the problem is - costly to find faults
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System Efficiency Index
• Compares at actual operation condition how close
the process is to ideal.
• Defines Carnot efficiency based on “reference
temperatures”
• Can be used for benchmarking
• Allows to define where in system losses are
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SEI - Standards under development
• Germany – UK – Sweden
– Define segments that can be meaningfully
compared
– Define reference temperature for each segment
– Define system boundraries (auxiliary loads)
– Establish benchmarking levels
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Global Industry need
tools and training
to optimise
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Dynamics in real systems not
well taken care off or understood