Steam measurements for the paper industry

UPM Kymmene is one of the largest European paper producers. At the Schongau site, a new gas and steam combined cycle power plant (CCGT) was commissioned in 2014 to supply heat and electricity to production and the surrounding community. Thanks to combined heat and power generation, peak efficiency of over 90 percent is achieved. This requires both extremely high steam parameters and the use of special materials such as P91.

A total of eight measuring points in the low-pressure, medium-pressure and high-pressure sections between DN 150 and DN 700 were equipped with SDF steam sensors. Thanks to the calibration of the measurements on an external test bench, the measurement uncertainties could be significantly reduced. This enables energy costs to be allocated precisely and transparently to individual cost centres. The calculation of steam and heat quantities is carried out in the AccuMind^® flow computer, which further reduces measurement errors thanks to linearization.

A central task of the end customer was to make the measurements as maintenance-free as possible. The experiences of the end customer with differential pressure measurements coincide with those of S.K.I. that the stability of the zero point of the differential pressure transmitter is the central bottleneck. Based on this practical knowledge, S.K.I. developed the automatic, demand-controlled zero point adjustment AccuFlo^® Zero, which was used in this project together with the VEGADIF transmitter from VEGA.

Thanks to the patented method, the flow measurements are always calibrated when there is a risk of decreasing accuracy due to long-term or temperature drift.

Conclusion: In this project, S.K.I. was able to prove that high-precision and reliable measurements can be achieved through the interplay of all competences, from classical flow measurement technology with SDF sensors to calibration and modern electronics.