Transcript Document

Calculation of the integrated energy
performance of buildings
EN 15316: Heating systems in buildings
Method for calculation of system energy requirements and
system efficiencies
Part 4-1: Space heating generation systems, combustion
systems (boilers)
Part 4-4 : Heat generation systems in buildings, building
integrated cogeneration systems
Part 4-7: Space heating generation systems, biomass
combustion systems
Contract: EIE/07/069/SI2.466698
Duration: October 2007 – March 2010
Version: July 7, 2009
FITTING INTO THE CALCULATION SCHEME
SERVICES
DHW
VENTILATION
LIGHTING
HEATING
COOLING
EN 13790
EN 15243
EN 15193
BUILDING
NEEDS
15316-3-1
EN 13790
EN 15241
EMISSION
&DISTRIBUTION
EN 15316-3-2
EN 15316-2-1
EN 15316-2-3
EN 15243
EN 15241
EN 15193
EN 15316-3-3
EN 15316-4-XX
EN 15243
EN 15193
LOAD
DISPATCHING
GENERATION
OVERALL
PERFORMANCE
EN 15603
slide 2
BUILDING
ENERGY PERFORMANCE
CALCULATION
HEATING SYSTEM
GENERATION
SYSTEMS
15316-4
HEATING SYSTEM
HEAT GENERATION
SERVICES
DHW
BUILDING
NEEDS
EMISSION
&DISTRIBUTION
VENTILATION
HEATING
COOLING
15316-3-1
EN 13790
EN 15241
EN 13790
EN 15243
EN 15316-3-2
EN 15316-2-1
EN 15316-2-3
EN 15243
EN 15241
LIGHTING
EN 15193
EN 15193
OVERALL
PERFORMANCE
Emission & control
EN 15316-2-1
QH,em,in
LOAD
SPLITTING
GENERATION
Building need
EN 13790
QH
EN 15316-3-3
EN 15316-4-XX
EN 15603
EN 15243
EN 15193
Distribution
EN 15316-2-3
15316-4-1
BOILERS
15316-4-2
HEAT-PUMPS
15316-4-3
THERMAL SOLAR
QH,dis,in
15316-4-4
CHP
Generation
EN 153146-4-XX
DISTRICT HEATING
EH,gen,in
PRIMARY ENERGY
EN 15603
ENERGY
PERFORMANCE
15316-4-5
15316-4-6
PHOTOVOLTAIC
15316-4-7
BIOMASS
15316-4-8
AIR HEATERS
slide 3
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
slide 4
Generation subsystem simplified energy balance
TOTAL & RECOVERED
AUXILIARY ENERGY
GLOBAL BALANCE
E H , gen , in  Q H , gen , out  Q H , gen , ls  Q H , gen , aux , rvd
TOTAL LOSSES AND
RECOVERABLE
LOSSES
slide 5
Biomass boiler
Generation subsystem simplified energy
balance
TOTAL & RECOVERED
AUXILIARY ENERGY
8
2
6
GLOBAL BALANCE
E H , gen ,in  Q H , gen , out  Q H , gen , ls  Q H , gen , aux , rvd
147
53
50
3
TOTAL LOSSES AND
RECOVERABLE
LOSSES
slide 6
Boiler directive data ???
slide 7
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 and
condensing boilers
• Tabulated (precaculated) values
– Simplification to cover common case and avoid calculation
burden to estimate simple repetitive cases
slide 8
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
0…30%...100% load) for auxiliary energy calculation
slide 9
2 - CORRECTED DATA AT
ACTUAL OPERATING CONDITIONS
4 – ACTUAL LOSSES
1 - TEST DATA AT
REFERENCE CONDITIONS
3 – ACTUAL LOAD
slide 10
Boiler directive data ???
slide 11
Sample seasonal boiler performance
method based on system typology
(typology method)
• This method of calculation is applicable only to boilers
for which the full load efficiency and the 30 % part load
efficiency values, obtained by the methods deemed to
satisfy Council Directive 92/42/EEC about Boiler
Efficiency [1], are available.
• These are net efficiency values (higher efficiency values,
referenced to the lower heat value of fuels).
• It is essential that both test results are available and that
the tests are appropriate to the type of boiler as defined
in Council Directive 92/42/EEC about Boiler Efficiency
[1], otherwise the calculation cannot proceed.
slide 12
Sample seasonal boiler performance
method based on system typology
(typology method)
The steps are as follows:
• a) Determine fuel for boiler type. The fuel for boiler type must be one
of natural gas, LPG (butane or propane) or oil (kerosene or gas oil).
• b) Obtain test data. Retrieve the full-load net efficiency ηPn,net and 30
% part-load net efficiency ηPint,net
• test results. Tests must have been carried out using the same fuel
as the fuel for boiler type.
• c) Reduce to maximum net efficiency values ηPn,net,max and
ηPint,net,max. Table A.1 gives the maximum values of net efficiency
depending on the type of boiler. Reduce any higher net efficiency
test values to the appropriate value given in Table A.1.
slide 13
Sample seasonal boiler performance
method based on system typology
(typology method)
slide 14
Sample seasonal boiler performance
method based on system typology
(typology method)
slide 15
Additional default data for condensing
boilers
slide 16
Sample seasonal boiler performance
method based on system typology
(typology method)
slide 17
Sample seasonal boiler performance
method based on system typology
(typology method)
slide 18
Boiler cycling generation energy balance
CALCULATION START
DISTRIBUTION NEED
CALCULATION RESULT
FUEL & AUXILIARY
BOILER
BURNER
LOSSES
slide 19
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
slide 20
Envelope
αge  2%
(0,5…5%)
Chimney
αch,on  10%
(3…15%)
BOILER CYCLING METHOD: LOSSES WITH BURNER ON
slide 21
Envelope
αge  2%
(0,5…5%)
Chimney
αch,off  1%
(0,2…3%)
BOILER CYCLING METHOD: LOSSES WITH BURNER OFF
slide 22
Condensing boiler
2…8 °C
to
10…60 °C
@ min..max
burner power
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
slide 26
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
slide 27
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.
slide 28
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.
slide 29
Calculation of the integrated energy
performance of buildings
EN 15316-4-4 : Heat generation systems in buildings,
building integrated cogeneration systems
Contract: EIE/07/069/SI2.466698
Duration: October 2007 – March 2010
Version: July 7, 2009
Combined heat and power
• CHP = combined
production of heat and
electrical power.
• The combined production
can result in high yields.
• Micro-CHP is defined as
all cogeneration
installations with an electric
capacity < 50 kW.
• The standard treats only
building integrated units
which are heat-led.
slide 31
slide 32
Scope of the standard
• Method for assessing the energy performance of combined heat and power
systems in buildings for space heating and/or domestic hot water.
• Method may be applied for:
• Determining energy performance of a combined heat and power system,
• Judging compliance with regulations expressed in terms of energy
targets,
• Optimisation of energy performance of a planned system,
• Assessing the effect of energy conservations measures on an existing
system.
• Only the calculation method and input parameters are normative. All values
should be given in national annexes.
• The framework for the calculation is described in EN 15603
slide 33
Principle of the method
The operation mode and the heating
demand of the building(s) determine
the total heat to be supplied by the
CHP unit. This excludes any
dumped heat.
Two possible operation modes:
• The cogeneration unit supplies
base load of the installation.
• The cogeneration unit is acting as
a boiler substitute.
Tflow
Base load
Boiler substitute
time
slide 34
Principle of the method
Heat demand of the space heating system:
- Required space heating needs
- Thermal losses from space heating emission
- Thermal losses from space heating distribution
(EN ISO 13790)
(EN 15316-2-1)
(EN 15316-2-3)
Heat demand the domestic hot water system:
- Required energy for domestic hot water needs
(EN 15316-3-1)
- Thermal losses from domestic hot water distribution (EN 15316-3-2)
- Generation (storage losses)
(EN 15316-3-3)
Besides heat demand, at least the following factors are to be taken into
account:
- water temperature (return/flow)
- start/stop effects
- part load operation
- air inlet temperature
slide 35
Description of the method
Two possible methods depending on operation mode:
• The ‘fractional contribution’ method
• CHP unit supplies only base load
• Only full load characteristics are important
• The ‘annual load profile’ method
• The CHP unit acts as a boiler substitute, providing (nearly) all heat
• Performance characteristics over the full load range, including part load
conditions, must be known
• Cogeneration unit is assumed to be heat-led so there is no dumped heat
slide 36
Description of the method
fractional contribution method
The calculation method comprises the following steps:
• Determine annual heating needs to be supplied by the cogeneration
installation
• Determine annual efficiency of cogeneration unit from test results
• Calculate annual fuel input for the cogeneration installation by dividing
heat to be supplied by the annual efficiency:
E chp , gen ; in 
Q chp ; gen ; out
 T ; chp ; an
• Annual system thermal loss of the cogeneration installation
• Annual electricity output of the cogeneration installation
slide 37
Description of the method
annual load profile method
The calculation method comprises the following steps:
• Determining the energy performance for full range of load conditions
• Determining the annual load profile
• Annual heat output of the cogeneration installation
• Annual fuel input for the cogeneration installation
• Electricity output of the cogeneration installation
• Annual average thermal efficiency of the cogeneration installation
• Annual system thermal loss of the cogeneration installation
So the method is rather similar to fractional contribution method. The
main difference is in the first two steps, the energy performance over
the full range of conditions and the annual load profile. This needs to
be accounted for because the performance of a CHP unit varies
strongly under part load conditions.
slide 38
Description of the method
annual load profile method
• Both thermal and electrical
efficiency are strongly dependent
on proportion of full load.
• For very low loads the electric
efficiency approaches 0%.
• Therefore, an annual load profile
has to made, giving operation
time per bin.
• Multiplying the load profile with
performance characteristics over
the full load range gives annual
performance of the CHP unit.
slide 39
Description of the method
annual load profile method
slide 40
Description of the method
annual load profile method
slide 41
More than 1 generator?
D.H.W. Need
QW,nd
500 kWh
Emission & distribution
Heating need, zone 1
QH,nd,Z1
1.000 kWh
Emission & control
Heating need, zone 2
QH,nd,Z2
2.000 kWh
Total needs
3.500 kWh
Emission & control
QW,dis,ls
25 kWh
QH,em,ls,Z1
40 kWh
QH,em,ls,Z2
120 kWh
QW,dis,in
525 kWh
QH,em,in,Z1
1.040 kWh
QH,em,in,Z2
2.120 kWh
η
73,1%
Storage
QW,st,ls
200 kWh
Distribution
QH,dis,ls,Z1
120 kWh
Distribution
QH,dis,ls,Z2
106 kWh
Qacc,in,W
QH,dis,in,Z1
QH,dis,in,Z2
Thermal solar
1.160 kWh
2.226 kWh
Boiler
Delivered energy
Total by carrier
Conv.
Factor
725 kWh
Overall
efficiency
Primary energy
QW,gen,out,sol
400 kWh
QHW,gen,out,boil 3.711 kWh
W W,gen,in,sol
20 kWh
W HW,gen,in,boil
148 kWh
Electricity
168 kWh
2,5
421 kWh
EHW,gen,in,boil
4.366 kWh
Fuel
4.366 kWh
1,0
4.366 kWh
Solar radiation
920 kWh
0,0
0 kWh
EW,gen,sol,in
920 kWh
4.787 kWh
slide 42
BR06
Boiler
• Olie-kedler skal have en nyttevirkning på mindst 91 % ved
CE-mærkning ved både dellast og fuldlast.
• Gas-kedler skal have en nyttevirkning ved Cemærkning på
mindst 96 % ved fuldlast og 104 % ved 30 % dellast.
• Kedler til fyring med biobrændsel og biomasse skal have en
virkningsgrad, der opfylder kedelklasse 3 i DS/EN 303-5.
• Direkte elopvarmning indgår med en vægtningsfaktor på
2,5.
slide 43