Tapping the Earth’s warmth for district heating
The heat that exists within the subsurface of the Earth offers a renewable, largely carbon-free method of providing heating for homes and businesses. In Iceland, for example, more than 90% of heating demand is met by tapping into underground water reservoirs that have been heated to high temperatures by volcanic activity.
In Slovakia, a major geothermal project aims to deliver heating to households in the country’s second-largest city, Košice. The specialist company Geoterm Košice has plans to drill geothermal wells in the nearby Košice Basin, which will access water with a temperature of more than 130°C at a depth of more than three kilometers.
Geoterm Košice
This is a unique project that has the potential to supply more than 170,000 residents of Košice with ecological heat. It will significantly contribute to reducing greenhouse gas emissions and thus to cleaner air in the entire Košice region.
The challenge: rapid cooling
Springing up at 55 liters per second under its own pressure, the geothermal water from Geoterm’s wells will transfer thermal energy via heat exchangers to a secondary district heating water circuit that will heat the city’s homes via a 16km pipeline network. The geothermal water will then be reinjected into the ground, creating a closed-loop system. In total, CO2 emissions in the city are projected to reduce by as much as 54,000 tons per year when the project is completed.
To test the potential of its planned wells, including yield, temperature and other parameters, Geoterm Košice designed a large, portable testing device. Like the wells themselves, the testing system taps hot water from below ground and then reinjects it. A crucial part of this process involves cooling the water before it is reinjected.
“The main challenge was the rapid cooling of a large amount of geothermal water and Güntner’s dry coolers play a significant role in doing that,” says Lubomir Fejko, Project Manager at implementation company M-D-J, who commissioned local company ABC Klíma Košice as the cooling contractors for the project.
A sophisticated control system
In the testing device’s primary cooling circuit, 135°C water is cooled to 55°C. In the secondary circuit, 80°C coolant is cooled to 35° using five Güntner V-shape VARIO Dry Coolers with EC fans. The fans are controlled using Güntner’s aicore™ air control system.
selected units
Güntner Products
Key advantages of the aicore™ air controller include:
- Energy saving. The ability to precisely regulate fan speed based on pressure or temperature optimizes power consumption.
- Plug-and-play commissioning. The system automatically programs parameters, making commissioning faster and easier. If an EC fan is replaced, the new fan is automatically recognized and configured with the correct settings.
- Intelligent system management. The controller serves as a system manager, monitoring key components throughout their lifecycle, including fan thermal contacts, power electronics, and control cabinet components.
- Communication and integration. The controller provides comprehensive communication interfaces to higher-level control systems for remote maintenance, improved monitoring, and operational transparency.
- Improved reliability and maintenance. Features such as proactive maintenance, automatic error detection, and winter operation modes ensure high, consistent performance and reduced downtime.
Keeping a city warm
When completed, the Košice Basin project will be one of Central Europe’s largest district heating systems. As well as delivering cozy warmth to many thousands of Košice residents, the system will also supply residual heat for other purposes, including agriculture and recreation, along the 16km route of the heat pipe.
“We are proud to have played a significant role in this very important project, which will create a clean, stable heat source for the city of Košice,” says Vladimir Kuzma, Area Manager, Güntner Slovakia. “This was a long-standing customer who trusts in the reliability of our products, which has been proven in many previous projects.”
