"Cold" heat network - a new heat source for heat pumps
The community of Nümbrecht, located in North Rhine-Westphalia, Germany, is situated in a picturesque area surrounded by green hills, lush forests, and gentle valleys intersected by rivers. The inhabitants of this region highly value their natural surroundings and strive to preserve its beautiful nature to the fullest extent. The ecological aspect has become a pivotal factor in implementing a pilot energy-saving project using heat pump technology.
The planning for the reconstruction in Büschhof began in 2010, and two years later the first residential building was connected to a renewable energy source - the cold district heating network. Today, 20 houses use the cold district heating network as a heat source for heat pumps. Environmentally friendly heating has not only reduced the environmental impact, but also allowed the project participants to reduce energy consumption by up to 80%.
How does the "cold heat network" work?
The purpose of the cold heat network, similar to a centralized heating system, is to transfer the necessary heat energy from the heat source to the consumers for heating purposes. However, in the case of the alternative "cold" heat network, the pipes are filled with brine (a non-freezing glycol mixture) instead of using water at high temperatures, as in traditional heating systems. Thus, the circulating heat carrier in this system ranges from -5 to +20 °C.
One of the advantages of this approach is that pipe insulation is not required, and there is also the possibility of utilizing additional energy from the ground.
In a traditional centralized heating system, the heat carrier is heated through the operation of thermal power plants or boilers. However, this technology has the drawback of significant heat losses through pipes laid in the ground.
In the case of using a "cold heat network," the temperature of the ground is generally higher than that of the brine. Therefore, due to the uninsulated pipes, additional energy absorption occurs, approximately 50 W per meter of the heat network. This geothermal energy serves as a heat source for highly efficient heat pumps installed inside each building. The brine returns to the heat network after passing through the heat pump, where it is again heated using the geothermal energy from the ground. If geothermal energy is insufficient to restore the network's operational characteristics, other renewable heat sources are utilized, such as solar panels, treated wastewater, and rainwater. Thus, 100% of the heat for the operation of heat pumps is provided by using renewable energy sources. The temperature of the cold heat network ranges from +4 to +21 °C. This solution has achieved a Seasonal Performance Factor (SPF) of heat pumps at a level of 4.23.
Over the past 5 years, the project has been operating successfully and evolving. The experience of Büschhof town confirms that this solution is effective and reliable. The "Cold Heat Network" has a wide potential for implementation in Ukraine, serving as a dependable environmentally friendly alternative to outdated boiler houses and thermal power plants.
-min.jpg "Hajster-6")
-1147x627.jpg "Hajster-8")
