ALLENDORF (wl) – VIESSMANN is one of the internationally leading manufacturers of heating, industrial and cooling systems. Consequently systems for all energy sources and power ranges were brought onto the market, such as solar technology modules, heat pumps or the first fuel cells heating device to be produced in a series in the world. Sensors suited to specific applications by SONTEC provide, for example,
operational resistance for solar plants of up to 300°C.
The family business VIESSMANN is considered a technological trendsetter in the heating sector and for decades has already been producing heating systems for oil and gas that are particularly low in harmful substances and energy efficient, as well as solar plants, wood combustion systems and heat pumps. Today the corporate group has around 11,500 employees worldwide, the group turnover currently amounts to 2.2 billion euros. The company has always recognised the principle of sustainability - one of six company policies which act as a sort of constitution at VIESSMANN.
One of the company policies with the title “top quality” additionally describes the in-house expectation for processes and products. As an employee in the Research and Development department,
Klaus-Dieter Arnold has to therefore fulfil high standards when working with solar plants with flat and vacuum pipe collectors: “Since it can reach up to 270°C at midday in high summer on the roof in a solar plant, all installed components should be able to safely withstand 300°C.”
A big challenge for the materials used, for example for the temperature sensors. These inform the in-house control technology which temperatures are currently “coming from the roof” and can be brought into the heat accumulator. “However, if the accumulator is heated up, the heat from the roof can no longer be discharged, and it can reach very high temperatures in the plant,” as Klaus-Dieter Arnold knows.
The best sensors can withstand 300°C
For years VIESSMANN have backed the competence of the manufacturer from Sauerland, SONTEC, in high quality special sensors. It was soon clear to the company’s experts that, with the company’s high demands, 300°C could not be achieved with the materials usually used for sensors and wiring. Even for the production of these high-performance sensors new paths had to be taken.
“In the company we began to have long series of tests with various wires,” remembers head of the company Patrick Sonntag. “Moreover our developers and production team searched for the best solution to reliably assemble the NTC sensor to safely connect the wire with the sensor element.” Instead of crimping, SONTEC decided on a welding process that is admittedly expensive but ultimately emerged as the optimum method. “This way proved itself to be the right one,” R&D team member Arnold was glad to report. This was because, according to him, the SONTEC solution did not show any weaknesses even during the tough VIESSMANN tests.