Steigerung der Energieeffizienz des pneumatischen Fasertransportes

  • Optimisation of energy efficiency of pneumatic fibre conveying

Möbitz, Christian Hartmut; Gries, Thomas (Thesis advisor); Merhof, Dorit (Thesis advisor)

Düren : Shaker Verlag (2021)
Book, Dissertation / PhD Thesis

In: Textiltechnik/Textile technology
Page(s)/Article-Nr.: VIII, 270 Seiten : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2021

Abstract

The textile industry is one of the most energy-intensive sectors of the manufacturing industry. In light of rising energy prices, energy consumption is an important investment criterion. About 45 – 50 % of the energy costs in fibre preparation are accounted for by pneumatic fibre transport. In order to avoid clogging of the conveying systems as well as damage and compaction of the fibres, the conveying fans are usually overdimensioned by about 30 % and are operated at maximum speed. The possibilities for geometric optimisation of the conveying systems are limited due to constructional boundaries. The greatest potential is to be achieved by reducing the air velocity and thus the speed of the conveying fan. The aim of the development is to reduce the air speed by at least 30 %. In the dissertation, a monitoring and control system is developed to control the speed of the conveying fan in an energy-optimised manner depending on the transport state of fibres and flakes. The selection of the sensors and the monitoring strategy is carried out according to the Nine-Step-Tool method, which is updated and extended in the thesis. The most significant characteristic variables for the transport condition are the fibre distribution factor and the temporal fluctuation of the fibre flow. A system model is derived from the tests on an industrial fibre conveying system. For the detection of the transport state, a Sugeno network is developed and trained with model data from the system model. The validation of the state monitoring is carried out using both the model data and the raw data from the industrial test. Furthermore, a two-degree-of-freedom control is developed and validated on the model. The reduction of the air velocity by 30 % leads to a reduction of the energy consumption by about 65 %. For a medium-sized conveying fan with a nominal energy input of 12.5 kW, this results in an annual savings potential of around 9,000 €. The payback period is 1 year. In industrial trials, energy savings of up to 74 % are possible, depending on the desired state of transport.

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