Substation with electric heat for ultra-low temperature district heating
Development and demonstration of a substation with electric heat for an ultra-low temperature district heating system. The electric heater raises the hot tap water the last degrees to a desired level. It enables a very low heat loss in the pip network and the possibility of much greater.
A new district heating (DH) concept ("5th generation DH) will be developed and demonstrated: New type DH substation with instantaneous heat exchanger and built-in electric heat for an ultra-low temperature DH system. Advantages:
- More than 50 % lower heat loss in the DH network compared to traditional system designs
- Increased potential for renewable energy (RE) and waste heat resources, as well as higher efficiency in heat pumps, geothermal energy, ect.
- Greater capacity in the district heating network
- Reduced investment costs for new pipe network due to smaller pipe dimensions
The concept includes power consumption, to a small extent, for partly heating of the domestic hot water heating. However the power consumption is here not seen as a disadvantage, especially if the power is based on RE.
The main project activities:
- Determination of prototype design
- Development of prototype at Danfoss
- Testing at Danish Technological Institute in the EnergyFlexHouse
- Measurements and analysis – final prototype design
- Analysis of advantage of the electric heat concept vs. traditional and low-temperature DH
- Full scale demonstration in 5-10 houses connected to a network with a central mixing shunt
- Measurements and analysis of demonstration
- Dissemination and market introduction
Overall objectives of the project are:
- Development of a prototype of a new district heating unit suitable for a supply temperatur of 40°C with an electric booster for the domestic hot water
- Small-scale demonstration in five (5) detached and existing single-family houses in Odder, Jutland
- Continuous operation, data measurement, data collection and regular data analysis of the ultra-low district heating network for up to a year
- Demonstrate and calculate the actual reduced heat loos from the existing district heating network
- Demonstrated and calculated the actual share of electricity for producing domestic hot water in relation to the amount of room heat.
Main results from the project are:
- It works all year and keeps a high DHW comfort in the houses without complaints from the residents
- The electrical share is only 2-7 % of annual heating energy to the houses
- Reduced DH heat loss by approx. 50 % compared to traditional district heating network m80/40/8°C
- Possible to use in both low-energy but also in existing buildings
- Enables an easy way of using low-grade heat sources and introducing electricity to the district heating network.
Key figures
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| COWI A/S | 0,15 mio. DKK | 0,27 mio. DKK |
| Danfoss A/S | 0,16 mio. DKK | 0,57 mio. DKK |
| Teknologisk Institut | 0,22 mio. DKK | 0,13 mio. DKK |
| Odder Varmeværk a.m.b.a. | 0,36 mio. DKK | 0,31 mio. DKK |
