More and more neighborhoods, buildings, and co-ownerships are adopting a district heating network.
While the installation of this system is not yet widespread in Belgium, district heating is popular among our European neighbors.
Specifically, what is it?
What is the difference between it and individual heating or a conventional gas boiler?
And how does this district heating system work?
We explain everything in this article.
What is District Heating?
The district heating system is also known as urban heating, heat network, or thermal energy network. Its objective is to centralize the production of thermal energy, heat or cold, and to distribute this energy through a network to end consumers.
This district heating system can supply thermal energy to private residences, such as an apartment building or a co-ownership, public or industrial buildings. Its installation usually occurs during the creation of a new district, but can also take place during major renovation works.
Operation of a District Heating System
To operate, district heating consists of three main elements:
Production
The Central Heating Plant
The central heating plant produces the thermal energy required for all consumers of the urban district heating system. To do this, it uses
A Decarbonized Energy Source
In some cases, sourcing can even be zero-carbon, meaning the heat network requires no carbon-based energy sources to produce heat and cold. This is the case, for example, if one opts for geothermal energy, wood, biogas, or waste heat. This sourcing ensures environmentally friendly heat consumption. As a result, the district heating system is a real opportunity to reduce one’s carbon footprint, decrease gas or fuel oil consumption, and significantly lower energy bills!
Distribution
Heat Transport
The thermal energy produced by the centralized heating plant is transported to buildings via a network of insulated, underground, and connected pipelines (called the primary network), and a heat transfer fluid. This fluid (e.g., water) is responsible for transporting the heat.
Overview
The world leaders in heat networks are the Russians. More than half of the world’s installed urban heating capacity is located in their country, serving no fewer than 44 million Russians. Unfortunately, these networks are 98% powered by carbon-based sources and are in a dilapidated state with numerous losses due to poor insulation. This underscores the importance of a well-designed, regulated, and maintained network.
Preventing Thermal Losses
Distribution faces a major challenge: heat transfer is inefficient. Therefore, solutions must be found to minimize thermal losses during transit. For efficient transport, the network’s design and regulation must be optimal.
The network design is established during its sizing and study. To choose the best arrangement, the design office must consider potential
Regulation takes place after the network’s commissioning. The operator must ensure that the system performs as expected. Among other things, they verify that the fluid is at the correct temperature at every point in the network.
The Interface with the End Consumer
The Substation
The thermal energy circulating in the pipelines arrives at a substation, the heat delivery point. This substation is a
It must comply with control standards defined by the State to meter consumers’ hot and cold consumption. Furthermore, it can also play a regulating role, through decentralized thermal storage or a booster, designed to raise the temperature locally, for example, for domestic hot water.
Return to the Central Heating Plant
Once the energy is delivered to the substation, the heat transfer fluid cools down while heating the building. The cold water returns through other pipelines to the central heating plant where it will be reheated and then sent back to consumers via the pipelines.
In Conclusion
For proper operation, district heating requires