Calculation of the integrated energy performance of buildings EN 15316: Heating systems in buildings

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Calculation of the integrated energy performance
of buildingsEN 15316 Heating systems in
buildings Method for calculation of system
energy requirements and system efficienciesPart
4-1 Space heating generation systems,combustion
systems (boilers)

• Laurent SOCAL
• EDILCLIMA/ Italysocal_at_iol.it

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The EU CENSE project (Oct. 2007 - March 2010)

• Aim of the project
• To accelerate adoption and improved effectiveness
  of the EPBD related CEN- standards in the EU
  Member States
• These standards were successively published in
  the years 2007-2008 and are being implemented or
  planned to be implemented in many EU Member
  States. However, the full implementation is not a
  trivial task
• Main project activities
• To widely communicate role, status and content of
  these standards to provide guidance on the
  implementation
• To collect comments and good practice examples
  from Member States aiming to remove obstacles
• To prepare recommendations to CEN for a second
  generation of standards on the integrated energy
  performance of buildings

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Brief introduction

• A brief introduction to the CENSE project and the
  CEN-EPBD standards is provided in a separate
  presentation

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More information

• More information and downloads www.iee-cense.eu

Disclaimer CENSE has received funding from the
Communitys Intelligent Energy Europe programme
under the contract EIE/07/069/SI2.466698. The
content of this presentation reflects the authors
view. The author(s) and the European Commission
are not liable for any use that may be made of
the information contained therein. Moreover,
because this is an interim result of the project
any conclusions are only preliminary and may
change in the course of the project based on
further feedback from the contributors,
additional collected information and/or increased
insight.
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FITTING INTO THE CALCULATION SCHEME
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BUILDING ENERGY PERFORMANCE CALCULATION
GENERATION SYSTEMS
HEATING SYSTEM
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More than 1 generator?
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Calculation principles

• Objective to calculate fuel and auxiliary energy
  consumption to fulfill the heat demand of the
  attached distribution subsystem(s)
• Basic input data heat required by the attached
  distribution sub-system(s) QH,dis,in
• The calculation method takes into account
• heat losses (flue gas, envelope, etc.)
• auxiliary energy use and recovery
• other input data
• location of the heat generator(s) (heated room,
  unheated room, ..)
• operating conditions (time schedule, water
  temperature, etc.)
• control strategy (on/off, multistage, modulating,
  cascading, etc.)
• Basic outputs is delivered energy as
• fuel consumption EH,gen,in
• auxiliary energy consumption WH,gen,aux

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Generation subsystem simplified energy balance
TOTAL RECOVERED AUXILIARY ENERGY
GLOBAL BALANCE
TOTAL LOSSES AND RECOVERABLE LOSSES
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Available methods

• Case specific
• Based on data declared according to Directive
  2002/92/CE
• Primarily intended for new or recent boilers for
  which this data is available
• Boiler cycling
• Primarily intended for existing systems
  andcondensing boilers
• Tabulated (precaculated) values
• Simplification to cover common case and avoid
  calculation burden to estimate simple repetitive
  cases

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Case specific method calculation procedure

• Get performance data in standard conditions at 3
  reference power levels
• Efficiencies at 100 and 30 load (according to
  Directive 92/42/EC)
• Stand-by losses power W at 0 load
• Correct data to take into account actual
  operating conditions (basically, the effect of
  water temperature in the boiler)
• Calculate losses power at 30 and 100 from
  corrected efficiencies
• Calculate losses at actual load by linear
  interpolation
• Use the same interpolation approach (based on
  data at 030...100 load) for auxiliary energy
  calculation

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2 - CORRECTED DATA AT ACTUAL OPERATING CONDITIONS
4 ACTUAL LOSSES
1 - TEST DATA AT REFERENCE CONDITIONS
3 ACTUAL LOAD
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Boiler directive data ???
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Boiler cycling generation energy balance
CALCULATION START DISTRIBUTION NEED
CALCULATION RESULT FUEL AUXILIARY
BOILER
BURNER
LOSSES
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Boiler cycling method

• For single stage burners, the calculation
  interval is divided into two basic operating
  conditions, with different specific losses
• Burner ON time, with flue gas and envelope losses
  
• Burner OFF time , with draught and envelope
  losses
• Loss factors are given as a percentage of
  combustion power (input to the boiler)
• Loss factors are corrected according to operating
  conditions(water temperature in the boiler, load
  factor)
• The required input load factor to meet output
  requirement is calculated
• Modulating and multistage boilers are taken into
  account with a third reference state burner ON
  at minimum power
• Condensation heat recovery is taken into account
  as a reduction of flue gas losses with burner ON

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Envelope age ? 2(0,55)
Chimney ach,on ? 10(315)
BOILER CYCLING METHOD LOSSES WITH BURNER ON
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Envelope age ? 2(0,55)
Chimney ach,off ? 1(0,23)
BOILER CYCLING METHOD LOSSES WITH BURNER OFF
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BOILER CYCLING METHOD EFFECT OF INTERMITTENCY
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Modulating boilers
BURNER LOAD
BOILER LOAD
CONTINUOUS OPERATION AT AVERAGE POWER
ON-OFF OPERATION _at_ MINIMUM POWER
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Envelope age ? 2(0,55)
Chimney ach,on,MIN ? 8(112)
BOILER CYCLING METHOD LOSSES WITH BURNER ON AT
MINIMUM POWER (MODULATING AND MULTI STAGE
BURNERS) MINIMUM POWER IS THE SET VALUE
(TYPICALLY 2550 OF MAX. POWER)
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Condensing boiler
Condensing boiler. The furnace is in the high
temperature upper part of the boiler
Condensing counter-current heat exchanger Flue
gases cool-down whilst doming down Return water
heats up whilst coming up. Condensate falls on
the bottom to be discharged
28 C to 1060 C _at_ min..max burner power
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Flue gas temperature
FLUE GAS TEMPERATURE and composition ?
CONDENSATION
BOILER EFFECT INCREASE IN TEMPERATURE FROM WATER
TO FLUE GAS
RETURN WATER TEMPERATURE HEATING SYSTEM
OPERATING CONDITIONS
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Why 3 methods

• No single method is the correct solution for all
  cases. A too simple method may not be able to
  show the effect of improvements whilst A
  detailed method may be time wasting for common
  repetitive situations.
• The boiler typology method aims to extreme
  simplicity.
• The case specific method is meant to use as far
  as possible boiler directive data.
• The boiler cycling method is meant to deal with
  existing boilers/buildings, to keep a connection
  with directly measurable parameters (flue gas
  analysis) and to calculate operating performances
  of condensing boilers.

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Parametering the methods

• Required data and default data for common
  situations are included in the annexes
• Annex A example of typology method
• Annex B default data for case specific method
• Annex C default data for boiler cycling method
• Annex E, F G calculation examples
• Default data can be adjusted through a national
  annex.

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More information

• More information and downloads www.iee-cense.eu

Disclaimer CENSE has received funding from the
Communitys Intelligent Energy Europe programme
under the contract EIE/07/069/SI2.466698. The
content of this presentation reflects the authors
view. The author(s) and the European Commission
are not liable for any use that may be made of
the information contained therein. Moreover,
because this is an interim result of the project
any conclusions are only preliminary and may
change in the course of the project based on
further feedback from the contributors,
additional collected information and/or increased
insight.