Diapositivo 1

Combined solar and heat pump systems
for residential buildings
Jorge Facão
LNEG
ARMAZENAMENTO DE ENERGIA
TÉRMICA EM CLIMATIZAÇÃO, PROJETO
EUROPEU TESSE2B
12th April 2016
Contents
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Introduction
Ground source heat pump
Statistical analysis of available market
Categorization
Graphical representation of solar and heat pump systems
Heat pump – renewable equipment
System boundaries for measurement of SPF and
Qusable
Default values for HHP and SPF
Laboratory test procedures for solar and heat pump systems
Comparison of the test methods to characterize the
performance of SHP
Work developed in LNEG
Introduction
• In a conventional solar thermal system, the daily solar production can
be stored for use only a few days;
• When the solar is less abundant the heat pump will take over the
duty;
• The heat pump source can be: air, ground, water from river or
aquifer;
• The solar collectors can be used as the provider of the primary heat
to heat pump. The two systems will operate in the so-called serial
mode;
• Hybrid technology combining solar thermal collectors and heat pump,
delivering heat to a building;
• Combisystem (domestic hot water and space heating);
• Due to CO2 considerations and scarcity of energy resources, the
electricity cost will increase in the future;
• Highly efficient heat pumps will be needed to substitute fossil heating
solutions. Combination with solar thermal can increase overall
performance.
Introduction
Performance map of an air-to-water heat Pump
Simplified heat gain of a covered and an unglazed collector
Ground source heat pump
Temperature of the undisturbed ground in northern hemispheres climate
as a function of the deep and time of the year
Statistical analysis of available market
Heating systems (space
heating and DHW) for
residential buildings which
are combined with solar
thermal systems in Germany
2012.
Companies
entering
the market of solar and
heat pump systems
Statistical analysis of available market
Surveyed companies by country
Surveyed systems by function
Surveyed systems by concept (P: parallel; S: series; R: regenerative)
Statistical analysis of available market
Surveyed systems by source
Surveyed systems by collector type
Surveyed systems correlated by collector and concept
Categorization
Association in parallel
Association in series
Regenerative association
Graphical representation of solar and heat pump
systems
Graphical representation of solar and heat pump
systems
Heat pump – renewable equipment
The European directive 2009/28/EC set the 20 % target for the overall
share of energy from renewable sources. Portugal had in 2005 a share of
20.5% and it is expected to reach in 2020 a target of 31%;
To quantify the share of renewable energy in each Member State it is
important to adopt suitable calculation methods;
The heat pumps are now considered in Europe as an equipment that
collect renewable energy, if his performance is above a certain limit.
ERES
Qusable
Heat pump – renewable equipment
The amount of aerothermal, geothermal or hydrothermal energy
captured by heat pumps to be considered energy from renewable
sources:
ERES = Qusable * (1 – 1/SPF)
Qusable = the estimated total usable heat delivered by heat
pumps. Only heat pumps for which SPF > 1,15 * 1/η shall be
taken into account,
SPF = the estimated average seasonal performance factor for
those heat pumps,
η is the ratio between total gross production of electricity and the
primary energy consumption for electricity production and shall be
calculated as an EU average based on Eurostat data.
Heat pump – renewable equipment
The (2013/114/EU) decision establish the guidelines for Member States
calculate renewable energy from heat pumps from different heat pump
technologies.
With power system efficiency (η) set at 45,5 % it implies that the minimum SPF
of electrically driven heat pumps (SCOPnet) to be considered as
renewable energy under the Directive is 2.5. For heat pumps that are driven
by thermal energy (η = 1) the minimum SPF (SPERnet) is 1.15.
System boundaries for measurement of SPF and Qusable
Climate conditions
Warm climate – climatic data from Athens
Average climate – climatic data from Strasburg
Cold climate – climatic data from Helsinki
Default values for HHP and SPF
electrically driven heat pumps
heat pumps driven by thermal energy
Laboratory test procedures for solar and heat pump
systems
CTSS – component testing and system simulation
WST – whole system testing
Comparison of the test methods to characterize the performance of SHP
CTSS - component testing and system
simulation
WST - whole system testing
Why perfom?
•Suitable for performance characterization of
customized systems set up by manufacturers or
retailers.
•Suitable for highly prefabricated systems with high product
sales.
Philosophy
•Cost reduction of testing larger product portfolios
by allowing identical components employed in
several systems to be tested only once (relevant for
labelling chemes).
•Cost reduction and more reliable performance information
for highly integrated systems that are always sold in one
package (not custom built).
Advantages
•Allows manufacturers with a larger variety of
system configurations to reduce testing costs.
•Precise parameterization of tested components
allows flexible performance evaluation for many
load patterns and climates by simulation under
given assumptions. Such simulation studies based
on experimental data can help to optimize design
parameters.
•If several products are to be tested, only differing
or missing system components need to be tested
(not all individual system configurations).
•Certain scaling options available.
•Only by testing the system as a whole proper function of all
components can be checked.
•Knowledge of the manufacturer's control strategy is not
needed.
•More accurate system performance evaluation.
Disadvantages
•For every component to be tested, an appropriate
model has to be available. This is often an issue if
new innovative systems are to be characterized.
•Simplifications could lead to uncertaities.
•Extrapolation to other boundary conditions is yet a difficult
task where research is on-going.
•No scaling available yet.
Related test
procedures
•Collector (ISO 9806)
•Store (EN 12977-3,4)
•Control (EN 12977-5)
•Heat Pump (under development)
•Procedure under development.
•DHW – only system – dynamic system test (ISO 9459-5)
Work developed in LNEG
Test 3 direct expansion solar assisted heat pump for DHW – no standards available
Methodology:
• Dynamic test through WST;
• Mathematic grey model developed in TRNSYS environment (only some
parameters known);
• The other characteristic parameters have been identified by two test sequences
and chosen by cross-comparison;
• Long term performance prediction evaluated by simulation.
Work developed in LNEG
Taping cycle L, according EN 16147:2011
Início da
extração
(h:min) /
Energia /
Tipo / Type
Energy
(kWh)
Start (h:min)
Tapping cycle
time
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
07:00
07:05
07:30
07:45
08:05
08:25
08:30
08:45
09:00
09:30
10:30
11:30
11:45
12:45
14:30
15:30
16:30
18:00
18:15
18:30
19:00
20:30
21:00
21:30
Total
0.105
1.4
0.105
0.105
3.605
0.105
0.105
0.105
0.105
0.105
0.105
0.105
0.105
0.315
0.105
0.105
0.105
0.105
0.105
0.105
0.105
0.735
3.605
0.105
11.655
DT desejado
(K) durante a
extração / DT
Min. DT (K) para
contagem da
energia útil / Min.
desired (K), to be
achieved during
tapping
counting useful energy
Pequeno / Small
Duche / Shower
Pequeno / Small
Pequeno / Small
Banho / Bath
30
Pequeno / Small
Pequeno / Small
Pequeno / Small
Pequeno / Small
Pequeno / Small
Limpeza chão / Floor cleaning
30
Pequeno / Small
Pequeno / Small
Lavagem louça / Dish washing
45
Pequeno / Small
Pequeno / Small
Pequeno / Small
Pequeno / Small
Limpeza casa / Household cleaning
Limpeza casa / Household cleaning
Pequeno / Small
Lavagem louça / Dish washing
Banho / Bath
Pequeno / Small
45
30
DT (K), start of
15
30
15
15
0
15
15
15
15
15
0
15
15
0
15
15
15
15
30
30
15
0
0
15
Work developed in LNEG
Parâmetro
Símbolo
Valor mínimo
Valor máximo
Parameter
Symbol
Minimum value
Maximum value
Step
Unidade
Coeficiente de perdas do coletor
b2
0
20
0.1
W/(m2K)
bu
0
0
0
s/m
c2
0
20
0.1
Ws/(m3K)
ho
0.1
0.9
0.01
-
lef
0
10
0.1
kJ/(hr.m.K)
N
1
100
1
-
UA
1
70
1
kJ/(hr.K)
UAb
0.1
5
0.1
kJ/(hr.K)
UAcond
2
150
1
W/K
UAt
0
5
0.01
kJ/(hr.K)
Zaux
0
0.25
0.01
0.25
0.75
0.01
Unity
Collector heat loss coefficient
Coeficiente perdas do coletor
dependente do vento
Collector heat loss coefficient (wind
dependence)
Dependência na temperatura do
coeficiente de perdas do coletor
Collector heat loss coefficient with
temperature dependency
Rendimento ótico do coletor
Collector optical efficiency
Condutibilidade térmica vertical
efetiva no depósito
Effective vertical thermal conductivity in
the store
Número de nós do depósito
Number of nodes for the store
Coeficiente de perdas do depósito
Heat loss coefficient of the store
Coeficiente de perdas do depósito
na base
Bottom heat loss coefficient of the store
Coeficiente de transferência de
calor no condensador
Condenser heat transfer coefficient
Coeficiente de perdas do depósito
no topo
Top heat loss coefficient of the store
Altura relativa do condensador
Relative position where condenser heater
is installed
Altura relativa da sonda de
Zsonda
temperatura para controlo do apoio
Relative position of temperature probe for
control auxiliary heater
Work developed in LNEG
Parâmetro
Parameter
b2
bu
c2
ho
lef
N
UA
UAb
UAcond
UAt
Zaux
Zsonda
Erro absoluto
Absolute Error [Wh]
Sequência / Sequence
10/09 – 26/09
FIT A
16.85
0
9.5
0.545
0.75
8
15
1.1
121
0.13
0.1
0.47
0.09
Sequência / Sequence
03/10 – 06/11
FIT B
16.8
0
9.5
0.78
0.2
8
16
1
123
0.12
0.1
0.47
4.54
Energia elétrica consumida
Electrical energy consumpsion [Wh]
Sequência / Sequence 10/09/2014 – 26/09/2014
Experimental
38809
FIT A
38809
FIT B
39558
Sequência / Sequence 03/10/2014 – 06/11/2014
Experimental
88697
FIT A
87281
FIT B
88692
Erro relativo
Relative error [%]
0.00
+1.93
-1.60
0.00
Work developed in LNEG
www.lneg.pt
Obrigado!