Filtration solutions for geothermal energy

Geothermal energy is the energy stored in the form of heat beneath the surface of solid earth. BOLLFILTER offers filtration solutions in both near-surface and deep geothermal energy sectors.
In the near-surface geothermal energy sector (down to 400 m), thermal water from groundwater wells can be used in HVAC systems in combination with heat pumps. These systems can provide heating in winter and cooling in summer.
In the deep geothermal energy sector (more than 400m), district heating and power generation are in focus.

District heating

At depths beyond 400m the geothermal heat from thermal water reservoirs can be used in „district heating“ systems. This sustainable source of energy is used to heat homes, buildings or industrial plants while generating nearly no CO2 emissions.

The hot thermal water is pumped up from deep underground, passed through a filter and then circulated through a heat exchanger.
The thermal water heats a secondary closed loop which distributes the heat to homes and businesses that are connected to the district heating network. Filters are often required in the secondary loop to protect the pumps, piping and heat exchangers used in the system.
Once the thermal water exits the heat exchanger it is re-injected back into the earth. In many cases regulations state that the thermal water needs to be filtered before re-injection to avoid contamination of the thermal water reservoirs.

District heating water filtration

District heating water, is not just heated water. The water quality is of great importance to improve productivity. Proper water filtration is a precondition of optimum protection of components in the district heating system.
BOLLFILTERs like the aquaBoll or the Simplex Type 1.53.1 are used to protect both the primary thermal water loop and the closed secondary loop of the district heating system. They are specially designed for this application and remove solids out of the water in order to protect heat exchangers, pumps and bore reinjection of the geothermal plant.

Your benefits:

Pump, pipe, valve, evaporator, preheater and condenser protection
No blockages of the geothermal system
Reduced maintenance requirements

Geothermal power generation

Geothermal energy can be used as sustainable, renewable source to generate electricity. An Organic Rankine Cycle (ORC) power plant is typically used to generate electricity using thermal water as a heat source.

In an ORC power plant, the thermal water is pumped through an evaporator which heats and vaporises an organic working fluid in a secondary loop. The vapor then drives a turbine connected to a generator that produces electricity. After the vapor leaves the generator it is passed through a water-cooled condenser, changing back into the liquid phase. The fluid is then pumped back through the evaporator and the process repeats itself.

Water filtration in ORC power plants

Filtration is required in the primary thermal water loop to protect the evaporator from blockages. The thermal water exiting then also needs to be filtered before re-injection to avoid contamination of the thermal water reservoirs.
In the secondary loop the working fluid may be filtered to protect the pump, preheater, evaporator and turbine. In the cooling water loop the water needs to be filtered to protect the condenser, cooling tower and pump.

BOLLFILTERs in ORC power plants

BOLLFILTERs like the aquaBoll or the Simplex Type 1.53.1 are used to protect both the primary thermal water loop, the secondary working fluid loop and the cooling water loop. Good filtration is essential in ensuring that the system operates at its optimum and blockages are avoided. Vital components such as the pumps, pipes, valves, evaporators, preheaters and condensers are protected by the filters against unwanted solids.

BOLL & KIRCH filtration experience in the geothermal energy sector

BOLL & KIRCH have more than 13 years of experience in the filtration of geothermal water.
Power plant operators as well as OEMs and PPEs in Germany, Switzerland, Austria and Hungary trust our expertise to minimize the risk of blocking production caused by coarse particles.
Our team can help you to choose the right filter depending on the flow rate, temperature and pressure of the thermal water to be treated. As geothermal water can contain many different types of particles, differing in size or composition, the choice of the right filter element is vital.