Generation of electricity through thermal and pressure driven airflows

Description

The energy demand for the operation of a road tunnel is considerable. This results on one hand in high operation costs and – as the production of electricity is not free of fossil fuels – in a significant CO2 footprint. There is an evident need to reduce energy costs as well as to improve the CO2 footprint. Due to the high energy costs, alternative options for generating electricity are being considered. The question arises as to whether mechanical ventilation systems can be used in reverse operation to generate electricity in road tunnels when pressure-driven air flows are present.
This paper deals with aspects of pressure-driven air flows in general and their use for generating electricity in electrical machines. As a first step, an analysis was carried out for standard 2-lane tunnels with different lengths and meteorological pressure differences. As a second step, recorded pressure differences between portals or shafts were evaluated for selected Austrian road tunnels.
The calculation of the annual energy quantities for possible electricity generation was based on the actual pressure differences in tunnel systems in the Austrian motorway and expressway network. Based on the available measurement data, those tunnel systems that have a high meteorologically related pressure difference were selected for further consideration. Taking into account the aerodynamic conditions and the expected efficiencies of electricity generation, an expected annual amount of energy can be estimated.

Period	16 Apr 2024 → 17 Apr 2024
Event title	12th International Conference Tunnel Safety and Ventilation
Event type	Conference
Conference number	12
Location	Graz, AustriaShow on map
Degree of Recognition	International