Transcript Low Energy Buildings - University of East Anglia

NBS-M017 - 2013
Carbon Reduction Strategies at the
University of East Anglia
Recipient of James Watt Gold Medal
2007
N.K. Tovey (杜伟贤) M.A, PhD, CEng, MICE, CEnv
Н.К.Тови М.А., д-р технических наук
School of Environmental Sciences / Norwich
Business School
Original buildings
Teaching wall
Library
Student
residences
2
Nelson Court
Constable Terrace
Low Energy Educational Buildings
Nursing and
Midwifery Thomas Paine Study Centre
School
Medical School Phase 2
ZICER
Elizabeth Fry
Building
Medical School
4
The Elizabeth Fry Building 1994
Cost 6% more but has heating requirement ~25% of average building at time.
Building Regulations have been updated: 1994, 2002, 2006, but building
outperforms all of these.
Runs on a single domestic sized central heating boiler.
Would have scored 13 out of 10 on the Carbon Index Scale.
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8
Constable Terrace - 1993
• Four Storey Student Residence
• Divided into “houses” of 10
units each with en-suite facilities
• Heat Recovery of body and cooking
heat ~ 50%.
• Insulation standards exceed 2006
standards
• Small 250 W panel heaters in
individual rooms.
Electricity Use
Carbon Dioxide Emissions - Constable Terrace
12%
21%
140
Appliances
120
Lighting
100
MHVR Fans
MHVR Heating
18%
Panel Heaters
Hot Water
18%
Kg/m2/yr
14%
80
60
40
20
0
17%
UEA
Low
Medium
6
Educational Buildings at UEA in 1990s
Queen’s Building 1993
Elizabeth Fry Building 1994
Elizabeth Fry Building Employs Termodeck principle and uses ~
25% of Queen’s Building
7
250
gas
200
kWh/m2/yr
150
100
50
0
Elizabeth Fry
140
Heating/Cooling
Hot Water
Electricity
120
2
electricity
Energy Consumption kWh/m /annum
Conservation: management improvements –
Low
Average
User Satisfaction
thermal comfort +28%
air quality
+36%
lighting
+25%
noise
+26%
A Low Energy Building is
also a better place to work in
100
80
60
40
20
0
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Careful Monitoring and Analysis can reduce energy
consumption.
8
ZICER Building
Low Energy Building of the Year Award 2005 awarded
by the Carbon Trust.
Heating Energy consumption as new in 2003 was reduced by further 50%
by careful record keeping, management techniques and an adaptive
approach to control.
Incorporates 34 kW of Solar Panels on top floor
The ZICER Building –
Main part of the building
• High in thermal mass
• Air tight
• High insulation standards
• Triple glazing with low emissivity ~
equivalent to quintuple glazing
The first floor
open plan office
The first floor
cellular offices
10
Operation of Main Building
Mechanically ventilated that utilizes hollow core ceiling slabs as supply air
ducts to the space
Incoming
air into the
AHU
Regenerative heat
exchanger
11
Operation of Main Building
Filter
过滤器
Heater
加热器
Air passes through
hollow cores in the
ceiling slabs
空气通过空心的板层
Air enters the internal occupied space
空气进入内部使用空间
12
Operation of Main Building
Recovers 87% of Ventilation
Heat Requirement.
Space for future
chilling
将来制冷的空间
Out of the
building
出建筑物
The return air passes
through the heat
exchanger
空气回流进入热交换器
Return stale air is extracted from
each floor 从每层出来的回流空气
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Operation of Regenerative Heat Exchangers
Stale air passes through Exchanger A and heats it up before exhausting
to atmosphere
Fresh Air is heated by exchanger B before going into building
Fresh
Air
B
A
Stale
Air
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14
Operation of Regenerative Heat Exchangers
After ~ 90 seconds the flaps switch over
Stale air passes through Exchanger B and heats it up before exhausting
to atmosphere
Fresh Air is heated by exchanger A before going into building
Fresh
Air
B
A
Stale
Air
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15
Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of
the year providing comfortable and stable temperatures
Warm air
Winter
Day
Warm air
Heat is transferred to the air
before entering the room
Slabs store heat from appliances
and body heat.
热量在进入房间之前被传递
到空气中
板层储存来自于电器以及人
体发出的热量
Air Temperature is
same as building fabric
leading to a more
pleasant working
environment
16
Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of
the year providing comfortable and stable temperatures
Cold air
Winter
Night
Heat is transferred to the air
before entering the room
Slabs also radiate heat back into
room
In late afternoon
heating is turned off.
热量在进入房间之前被传递到
空气中
板层也把热散发到房间内
Cold air
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Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of
the year providing comfortable and stable temperatures
Cool air
Summer
night
Draws out the heat accumulated
during the day
Cools the slabs to act as a cool
store the following day
night ventilation/
free cooling
把白天聚积的热量带走。
冷却板层使其成为来日的冷
存储器
Cool air
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Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of
the year providing comfortable and stable temperatures
Warm air
Summer
day
Slabs pre-cool the air before
entering the occupied space
concrete absorbs and stores heat
less/no need for air-conditioning
空气在进入建筑使用空间前被
预先冷却
混凝土结构吸收和储存了热量
以减少/停止对空调的使用
Warm air
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Energy Consumption (kWh/day)
能源消耗（kWh/天）
Good Management has reduced Energy Requirements
Space Heating
Consumption reduced
by 57%
1000
800
800
600
400
350
200
0
-4
-2
0
2
4
6
8
10
12
14
16
18
Mean |External Temperature (oC)
Original Heating Strategy
New Heating Strategy
原始供热方法
新供热方法
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Life Cycle Energy Requirements of ZICER compared to other buildings
与其他建筑相比ZICER楼的能量需求
自然通风
221508GJ
54%
28%
51%
使用空调
384967GJ
34%
建造
209441GJ
Materials Production 材料制造
Materials Transport 材料运输
On site construction energy 现场建造
Workforce Transport 劳动力运输
Intrinsic Heating / Cooling energy
基本功暖/供冷能耗
Functional Energy 功能能耗
Refurbishment Energy 改造能耗
Demolition Energy 拆除能耗
29%
61%
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Life Cycle Energy Requirements of ZICER compared to other buildings
300000
ZICER
250000
Naturally Ventilated
GJ
200000
Air Conditrioned
150000
100000
50000
0
0
5
10 15 20 25 30 35 40 45 50 55 60
80000
Years
GJ
60000
Compared to the Air-conditioned
office, ZICER as built recovers
extra energy required in
construction in under 1 year.
40000
20000
ZICER
Naturally Ventilated
Air Conditrioned
0
0
1
2
3
4
5
6
7
8
9
10
Years
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ZICER Building
Photo shows
only part of top
Floor
• Mono-crystalline PV on roof ~ 27 kW in 10 arrays
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• Poly- crystalline on façade ~ 6.7 kW in 3 arrays
Arrangement of Cells on Facade
Individual cells are connected
horizontally
Cells active
Cells inactive even though
not covered by shadow
As shadow covers one column
all cells are inactive
If individual cells are connected
vertically, only those cells actually in
shadow are affected.
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24
Performance of PV cells on ZICER
Wh
%
100
100
Block1
90
90
Block 2
80
80
Block 3
70
70
Block 4
60
60
Block 5
50
50
Block 6
40
40
Block 7
30
30
Block 8
20
20
Block 9
10
10
Block 10
0
0
radiation
9
10
11
12
13
14
All arrays of cells on roof
have similar performance
respond to actual solar
radiation
15
Time of day
%
Wh
The three arrays on the
façade respond differently
200
180
160
140
120
100
80
60
40
20
0
100
90
80
70
60
50
40
30
20
10
0
9
10
11
12
13
Time of Day
14
15
Top Row
Middle Row
Bottom Row
radiation
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Elevation in the sky (degrees)
20
18
16
14
12
10
8
6
4
2
0
120
8.00
9.00
150
10.00
180
210
12.00
13.00
14.00
Orientation relative to True North
11.00
15.00
240
16.00
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Elevation in the sky (degrees)
25
January
May
September
P1 - bottom PV row
February
June
October
P2 - middle PV row
March
July
November
P3 - top PV row
April
August
December
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15
10
5
0
6.00
7.00
8.00
9.00
10.00
11.00
12.00
Time (hours)
13.00
14.00
15.00
16.00
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Use of PV generated energy
Peak output is 34 kW 峰值34 kW
Sometimes electricity is exported
Inverters are only 91% efficient
• Most use is for computers
• DC power packs are inefficient
typically less than 60% efficient
• Need an integrated approach
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Original Way Heat was supplied to UEA campus
• Three 8MW oil fired boilers - 83 – 85%
efficient on full load, but only ~25% on
low load.
• Heat distributed via ~ 4 km of pipe
work which was originally poorly
insulated leading to losses of 500 kW or
more – now ~ 200 kW.
• ~ 1984 small 4 MW boiler added for use
at times of low demand
• 1987 all boilers converted to run on
either gas or oil
• 1998 – one boiler removed and 3 CHP
units installed
• 2004 – absorption chiller installed to
provide cooling throughout campus
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Conversion efficiency improvements – Building Scale CHP
3% Radiation Losses
11%
61% Flue
Flue Losses
Losses
36%
86%
Gas
Localised generation makes use of
waste heat.
Reduces conversion losses
significantly
Exhaust
Heat
Exchanger
Engine
Heat Exchanger
Generator
36% Electricity
50% Heat
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UEA’s Combined Heat and Power
3 units each generating up to 1.0 MW electricity and 1.4 MW
heat
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Conversion efficiency improvements
Before installation
1997/98
MWh
electricity
gas
oil
19895
35148
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Total
Emission factor
kg/kWh
0.46
0.186
0.277
Carbon dioxide
Tonnes
9152
6538
9
Electricity
After installation
1999/
Total
CHP export
2000
site generation
MWh 20437 15630
977
Emission kg/kWh
-0.46
factor
CO2
Tonnes
-449
15699
Heat
import boilers CHP
oil
total
5783
14510 28263 923
0.46
0.186
0.186 0.277
2660
2699
5257 256 10422
This represents a 33% saving in carbon dioxide
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Trailblazing to a Low Carbon Future
Low Energy Buildings
Low Energy Buildings
Photo-Voltaics
• Low Energy Buildings
• Absorption Chilling
• Effective Adaptive Energy
Management
• Advanced CHP using
Biomass Gasification
• Photovoltaics
Efficient CHP
• Combined Heat and Power
Absorption Chilling
• World’s First MBA in
Strategic Carbon
Management
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Conversion efficiency improvements
Load Factor of CHP Plant at UEA
Demand for Heat is low in summer: plant cannot be used effectively
More electricity could be generated in summer
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绝热
Heat rejected
高温高压
High Temperature
High Pressure
节流阀
Throttle
Valve
Compressor
冷凝器
Condenser
蒸发器
Evaporator
低温低压
Low Temperature
Low Pressure
压缩器
为冷却进行热提
取
Heat extracted
for cooling
A typical Air conditioning/Refrigeration Unit
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Absorption Heat Pump
外部热
Heat from
external source
绝热
Heat rejected
高温高压
High Temperature
High Pressure
吸收器
Desorber
节流阀
Throttle
Valve
冷凝器
Condenser
蒸发器
Evaporator
为冷却进行热提
取
Heat extracted
for cooling
低温低压
Low Temperature
Low Pressure
热交换器
Heat
Exchanger
W~0
吸收器
Absorber
Adsorption Heat pump reduces electricity demand
and increases electricity generated
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A 1 MW Adsorption chiller
1 MW 吸附冷却器
• Uses Waste Heat from CHP
• provides most of chilling requirements
in summer
• Reduces electricity demand in summer
• Increases electricity generated locally
• Saves ~500 tonnes Carbon Dioxide annually
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The Future: Biomass Advanced Gasifier/ Combined Heat and Power
•
•
•
•
•
Addresses increasing demand for energy as University expands
Will provide an extra 1.4MW of electrical energy and 2MWth heat
Will have under 7 year payback
Will use sustainable local wood fuel mostly from waste from saw
mills
Will reduce Carbon Emissions of UEA by ~ 25% despite increasing
student numbers by 250%
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Trailblazing to a Low Carbon Future
Photo-Voltaics
Efficient CHP
Advanced Biomass CHP using Gasification
Absorption Chilling
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Trailblazing to a Low Carbon Future
Efficient CHP
1990
2006
Students
Floor Area (m2)
5570
138000
CO2 (tonnes)
CO2 kg/m2
CO2 kg/student
Absorption Chilling
14047
207000
Change since
1990
+152%
+50%
2011
16000
220000
Change since
1990
+187%
+159%
19420
140.7
21652
104.6
+11%
-25.7%
14000
63.6
-28%
-54.8%
3490
1541
-55.8%
875
-74.9%
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Results of the “Big Switch-Off”
Target Day
With a concerted effort savings of 25% or more are possible
How can these be translated into long term savings?
41
Energy Consumption (kWh/day)
UEA’s Pathway to a Low Carbon Future: A summary
1000
800
600
400
O
200
0
-4
-2
0
2
4
6
8
10
12
14
16
18
o
Mean |External Temperature ( C)
Original Heating Strategy
1.
2.
Raising Awareness
3.
Improving Conversion
Efficiency
4.
5. Offset Carbon
Emissions
New Heating Strategy
Good Management
Using Renewable Energy
42
Conclusions
UEA has achieved Carbon reductions by:
• Constructing Low Energy Buildings
• Effective adaptive energy management which has typically
reduced energy requirements in a low energy building by
50% or more.
• Use of Renewable Energy: Photovoltaic electric generation
but opportunities were missed which would have made
more optimum use of electricity generated.
• The existing CHP plant reduced carbon emissions by
around 30%
• Adsorption chilling has been a win-win situation reducing
summertime electricity demand and increasing electricity
generated locally.
• Awareness raising of occupants of buildings can lead to
significant savings
• By the end of 2013, UEA should have reduced its carbon
emissions per student by 70% compared to 1990.
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