Laboratory Sustainability

The Sustainability Laboratory has three main focuses, which are also offered as part of the teaching:

• Sustainable energy industry and energy storage
• Smart Systems and energy management
• Sustainability and energy efficiency in production systems

Our current research activities centre around thermal energy storage systems (especially high-temperature latent heat storage systems), Smart Systems, and integrated energy management in the transition to renewable energies.

In interdisciplinary and cross-faculty projects, the NP Laboratory serves as the central pillar for the Faculty of Engineering Management’s membership of the Institute of Sustainable Energy Engineering and Mobility (INEM).

Latent heat storage systems are phase-change storage systems, this means that a phase change takes place in the storage medium during both the charging and the discharging process, thus allowing a large amount of energy to be absorbed or released with only a small change in temperature.

As part of the research being undertaken in the Sustainability and Production Laboratory, a latent heat storage system with sodium nitrate with a melting point of 306°C is used as the phase transition material, thus allowing the energy which is coupled in electrically to be stored at a high temperature level and hence a high exergonic level. Thick-film heaters for the electrical charging are being developed in collaboration with the Mechatronics Faculty. The particular challenge here is the fact they are used at temperatures up to 350°C and come into contact with the molten salt (NaNO3). The greatest challenge with latent heat storage systems is the discharging characteristic. Since the storage medium solidifies at the heat transfer surface, the film increases in thickness and thus the thermal resistance increases, which means that the discharging power output decreases greatly over time. An innovative discharging concept with an active scraping function was developed in the laboratory, and is being tested and developed further on the high-temperature storage system and also with paraffin in the low-temperature range as part of student projects.

Power output curves and total energy consumption of the modular production stations (MPS) of the Festo demonstration unit at the Automation Systems Laboratory of the Faculty of Mechatronics and Electrical Engineering

Power output curves and total energy consumption of the modular production stations (MPS) of the Festo demonstration unit at the Automation Systems Laboratory of the Faculty of Mechatronics and Electrical Engineering

An energy management system based on three Raspberry Pis and its own network environment was developed as part of an interdisciplinary student project. The system is able to calculate energy consumption levels occurring during the runtime from different data and processes and display them to the user.

Three processes of the Festo demonstration unit in the Automation Systems Laboratory of the Faculty of Mechatronics and Electrical Engineering were selected for investigation and equipped with measuring instances in order to be able to implement digital interfaces. Some individual stations are already able to transmit status data via TCP/IP. In Node RED, energy consumption values are calculated from these status data. This requires the presence of so-called “flows”, whose individual “nodes” take over various calculation and presentation tasks. The consumption values per unit produced and the cumulative total consumption is displayed to the user.

This management system is thus initially a monitoring system which provides the user with ideas on optimisation opportunities and an overview of the resources consumed by the processes. Later on, individual limiting values have to be determined so that a comparison can subsequently be made of the extent to which changes lead to improvements. In addition, it is possible to detect at an early stage when corresponding components no longer run smoothly and their energy consumption therefore increases.