Post on 25-Oct-2021
This project has received funding from the European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant agreement no ENER/FP7/609127/READY
District heating topics
List of topics
• Individual heating vs district heating – competitiveness
• Heating and cooling – Tåstrup case
• District heating and cooling – Vaxjö case
• Use of surplus heating – Vaxjö case
• Smart meters in district heating – an investigation from Aarhus
• Heat pump in a district heating system
• Summer shut down of production
This project has received funding from the European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant agreement no ENER/FP7/609127/READY
Introduction to district heating in Denmark
Nina Detlefsen
Kolding
Copenhagen
Buildings with district heating
1.7 mill.
Price reduction in 3 years
13%
400Heating companies
Danish District Heating Association
Renewable energy
53%
99%District heating supply
From black to green energy
100% RE by 2050
Biomass and biogas
Power to heat and recycling heat
Efficiency and coherent
cooperation
Intelligent utility with ICT
Fuel free energy
Urbanization = megatrend
We want to live in large cities
To live in large cities is a goal for many people.
High density of humans and activities requires intelligent and sustainable solutions.
Energy must be supplied in a secure and connected system based om environmental friendly harvest of energy.
Past
Present and future
Intelligent energy supply
Example. Denmark has 900 water treatment plants
Water supply
SewageWater
treatment
Point source
Heat PumpDistrict heating
Sludge BiogasBio
Methane
Gas engine
Power
District heating
Climate adoption
Grey water
District Heating – From oil to multiple fuels
Change in fuel used for district heating generation 1972 – 2012
Coal
Electricity for heat pumps
Natural gas
PJ
Renewable energy
Oil
Waste – non biodegradable
From fuels to no fuels
Fossil fuels
• Fossil share of waste
• Natural gas• Oil• Coal
RE fuels
• Agricultural waste• Biogas • Biomasso Straw (annual)o Wood chip (years)
o Wood pellets (years)o Biodegradable share
of waste
Fuel free heat
• Recycling heat• Solar thermal• Geothermal• Power (from RE)o Heat pumps and
electric boilers
Multiple source energy system
Coal
Oil
Natural gas
Wood chips
Wood pellets
Straw
Biogas
Solar thermal
Recycling heat
Heat pumps
Waste (fossil)
Wind power
Heat and power
CHP
Boilers
Direct
Conversion
Storage
District heating
Power
District cooling
Geothermal
LEGO® model of Brædstrup CHP with 8,000 m² / 5.6 MW Solar thermal
Large storage of hot water
Dam store – highly efficient with solar thermal
Coverage for solar thermal increases from 20% to 50% with a storage.
Vojens Fjernvarme generates 50% of the district heating from 70,000 m2 solar thermal and a 203,000 m3 dam store. Opened in 2015.
VEKS are designing a 60,000 m3 storage for day balancing.
Aalborg Forsyning are designing a 1,000,000 m3 seasonal storage.
CHP in Denmark460 units generates district heating
§ Heat units and industrial units. Central and decentralized plants.
Manny different fuels
§ Coal, biomass, natural gas, waste
and biogas.
§ Solar thermal, power to heat and a little geothermal.
Large penetration
§ 40.000 km district heating pipelines
§ 65% of buildings uses district heating.
Kilde: Energistyrelsen
District Heating from CHP – Large and small
District heating from power plant cooling water is still a large share
PJ
Industrial, CHP Industrial, heat only
Electricity production in Denmark
Decentralized CHP-units
Large variations between units
Efficiency
Calculated as:
Total output/productionTotal input of fuels
RE share
Questions?
This project has received funding from the European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant agreement no ENER/FP7/609127/READY
District heating or individual heating in new areas
Introduction
Heatdensity matters
Prices in different networks
• Yearly heating prices for district heating in different networks
• The distance between houses is increasing
District heating Individual heating
Competitiveness
Yearly heating prices of district heating compared to individual solutions
Conclusions
• District heating in new areas – good idea?
• Cheap heating
• Integrated energy system
• Low total investments
• Large investment costs
• Requires common consensus
Advantages Disadvantages
For each area: Make individual business cases
This project has received funding from the European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant agreement no ENER/FP7/609127/READY
Innovative smart city solutions
For sustainable planning using smart for greenbusiness solutions within transport, district heating and cooling, building
retrofitting, renewable energy, energy storage and balancing.
This project has received funding from the European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant agreement no ENER/FP7/609127/READY
District Heating and CoolingStrategic solutions for low-carbon energy systems
TechniquesDistrict heating and cooling
CO2 is absorbed by
the growing forest
Ash• Provides minerals• Fertilises• Counteracts acidification
Biofuel • Branches and tops from logging• Wood chips• Bark and sawdust
Hospitals, offices, shopping malls
Flue-gas treatment
Steam boiler
Turbine Generator
Condenser
Cooling unit
DISTRICT HEATING
DISTRICT COOLING
10-16 °C
6-8 °C
Produce green electricity and heat from biomass
CO2 is absorbed by the growing forest
Efficient production gives sustainable district cooling• DC network in Växjö is flexible, energy efficient and available
• Innovative DC cycle network
• Total capacity 11.5 MW + 2.37 MW (excluding free cooling)
• 28 Customers connected to the grid
• Consumed energy: 10 417.21 MWh (2017)
Integration of two production plants gives new opportunities
• After the DC network was fully integrated, the system is more efficient, environmentally friendly and economically beneficial.
Reduced electricity by using district heating
• Lower the electricity consumption by 25 % compared to before the integration.
0
500
1000
1500
2000
2500
Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec
MWh
Production of energy before the integration with two
separated district cooling networks
Total production
SVV
V-Mark
0
500
1000
1500
2000
2500
Jan Feb Mar Apr Maj Jun Jul Aug Sep Okt Nov Dec
MWh Production of energy demand after the integration
Total produktion
SVV
V-Mark
More flexible production of cooling
• Cooling tower to increase the capacity of existing machines
Reduce heat losses
Heat losses are expected to be reduced by 58 % in a
low temperature district heating network compared to
a traditional district heating system with traditional
pipes, insolation and temperatures.
From 105°C to 65°C
Traditional District Heating SystemDimensioning lifetime of pipes 35 years
Design outdoor temperature (DOT) -19 °C
Flow temperature of district heating at customer-central
at DOT (winter season)
105 °C
Flow temperature of district heating at customer-central
at DOT (summer season)
65 °C
Return temperature from the customers centrals at max
load (winter season)
50 °C
Return temperature from customer centrals at DOT
(summer season)
50 °C
Low Temperature District Heating SystemDimensioning lifetime of pipes 35 years
Design outdoor temperature (DOT) -19°C
Flow temperature of district heating at customer-central
at DOT (winter season)
65 °C
Flow temperature of district heating at customer-central
at DOT (summer season)
65 °C
Return temperature from customer centrals at max load
(winter season)
38 °C
Return temperature from the customers centrals at DOT
(summer season)
22 °C
Self-organising Thermal Operational ResourceMagnagement
An innovative DHC networks’ controller for enhanced district energy efficiency
For typical networks with a smaller sustainable energy source (biomass boiler, heat pump) and a larger fossil backup è Elimination of fossil fuel.
For networks coupled to the electric grid by heat pumps/CHPs è Switching the devices at interesting power price.
For more sophisticated networks: balance supply and demand of heat/cold in a cluster è increased efficiency.
Demonstration sites in STORM
A very typical 3rd generation network
• 180 customers
• 10 large buildings connected to the STORM controller (36 % of the total energy consumption in Rottne)
• 2 wood chips boiler (1.5 MW + 1.0 MW) + bio fuel boiler (3MW) (backup)
• Design temperature 90-60°C
• Objective: eliminate the operation of the expensive peak fuel boiler
Rottne, Växjö, Sweden
A highly innovative 4th generation network
• Very low temperatures (‘hot’ pipe 28°C – ‘cold’ pipe 16°C)
• Heating & cooling
• Coupled to underground mine water storage
• 11 buildings connected (4 clusters) to the STORM controller
• Objective: balancing of heat/cold producers and consumers
Heerlen, the Netherlands
Smart Heat Grid in Rottne
Surplus heatingDistrict heating and cooling
How to use surplus heating in Växjö
Potential solutions of increasing the amount of waste heat
• Wasted heat from computer center
• Potential wasted heat recovery from process production industry
• Potential wasted heat from grocery store
• Potential of utilize wasted heat from industry processes
• A technique of utilising wasted heat from a customer building.
• The purpose of this deliverable is to describe the design of how one can utilise wasted heat from a cooling system and at the same time supply
the district heating network.
Design note for implementing wasted heat recovery technology
1. Heat is transferred from the customers cooling machine to the refrigerant liquid in the evaporator, causing the refrigerant liquid to evaporate.
2. The pressure of the refrigerant vapor is increased due to work added in the compressor. Since the compression isn’t isentropic, the temperature of the vapor will rise a bit further.
3. In the condenser the vapor releases heat to the district heating water and goes through a second phase change once again turning in to liquid.
4. The choke valve decreases the pressure, ensuring that there will be no mix of vapor and liquid on the low pressure side.
Design note for implementing wasted heat recovery technology
This project has received funding from the European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant agreement no ENER/FP7/609127/READY
Sea water driven heat pump –A multifaceted DH supply in Aarhus
Introduction
What is a smart city?
Aarhus DH system
Climate strategy
Aarhus DH system
• Supply to:• AVAs own distribution network• 7 consumer owned DH companies• 3 neighbouring municipalities
• Approximately 3.100 GWh in 2016 from:• Studstrup CHP plant approx. 50%• 2 waste incineration plants approx. 25%• Lisbjerg biomass fired CHP plant approx. 20%• Surplus heat approx. 3% [from where?]• Electric boiler approx. 1%• Oil boilers <1%• Biogas fired plants <1%
3 straw fired areas (green arrows)Geding 0.25 MW oil boiler (grey arrow)
Aarhus DH system
Technical system
System sketch of the heat pump
Location
Project budget
Expected heat demand development
Comparison of two options
System sketch of the heat pump
Location of the heat pump
Visibility