Unholz Wärme AG, Greifensee heating network, Switzerland

Faithful and reliable companion - Schmid heaters

Faithful and reliable companion - Schmid heating systems
The first heating center was installed as early as 1985 - a Schmid boiler with 500 kW and a Wood chips warehouse right next door. With this central heating unit, the long-distance pipeline south was created, which supplied three apartment buildings, a commercial building and 1500m3 of old properties with heat. In the following years, various renovations and expansions of the boiler capacities were added. In 1994 the stoking was automated and also the long-distance pipeline west was realized. In 2014, a 90,000-liter storage tank followed, and a year later, the second UTSR 2400 boiler with Denox system and electrostatic precipitator of IS Save Energy was installed. The long-distance pipeline network has also grown during this time. In the meantime, more than 2.6 kilometers of pipeline have been laid, so that various school buildings and the "Städtli Greifensee" are heated with district heating from Unholz.

Always one step ahead of technology - Revolution adaptive
The friendly cooperation as well as the peculiarity to always have the latest, Beat Unholz has probably inherited from his father. Therefore, it was crystal clear to him that the new UTSR visio 2400 boiler, which replaces a UTSR-1200 and is installed next to the UTSR-3200 built in 1999, must be state-of-the-art. Whether the brand new and innovative Revolution adaptive control system would be installed was therefore not a question.

"If we're going to renew and modernize, we're going to do it to the very latest standards," says Beat Unholz.

In November 2021, for example, the Revolution adaptive was installed for the first time on a customer plant of the size UTSR 2400 visio with the Schmid PLC control system.

New control - Revolution adaptive
Changing humidity of the fuel - automatic firing control.
The fuel of unwood consists of moist maintenance and forest wood as well as dry residual wood from sawmills. With the previous PersonalTouch visio control system, the plant has to be manually readjusted again and again in order to achieve the highest possible efficiency. When the fuel change takes place is not always easy for the plant maintenance staff to estimate and therefore involves a lot of monitoring effort.

The new Revolution adaptive control generation detects the fuel quality used. This is done on the basis of the fuel water content, the heat output generated, the combustion temperature and the current grate occupancy. Based on these values, the solar output of the plant is automatically tracked without manual intervention.

"Even back then - when we had no idea about a heating system but enough "worthless" wood, Hans-Jürg Schmid already advised us well. To this day, we have great confidence in the technology and the team at Schmid and have been able to count on a competent and friendly customer relationship for over 30 years. We are proud to operate two Schmid boilers with the latest heating technology." Unholz family, Unholz Wärme AG.

area of application
District heating

fuel
Wood chips

type of combustion system
Feed grate firing
UTSR-2400.42-1 visio

Control
Revolution adaptive
Capacity Total
Nominal power M 50% 2400 kW / Partial load M 30% 720 kW

Discharge
Moving floor

Exhaust gas dedusting
Multicyclone / electrostatic precipitator SaveEnergy consisting of

In use since
Boiler: September 2021 / Revolution adaptive: November 2021