Review of the experience in utilising waste heat from the metro

Abstract

The exhaustibility of traditional fossil energy sources is leading to the increasing use of unconventional energy sources. One of the most promising areas of alternative energy is the use of low-potential ground energy to heat buildings and structures for various purposes using a heat pump. The subway generates a significant amount of heat, especially when trains are braking, stopping on platforms and picking up speed when they start moving from the station. Thus, to combat the rise in temperature in tunnels and stations, a complex ventilation system is designed, including shafts, fans, and under-platform exhaust. In modern Ukrainian subways, the ventilation system is designed to cope with the rising temperatures in tunnels and stations. This traditional approach results in high energy consumption for running fans and ignores the possibility of using the extracted heat above ground in buildings. Techniques such as lining underground railway tunnels with heat exchanger segments, installing a heat exchanger in a subway ventilation shaft, installing geothermal heat pumps next to a subway tunnel, installing energy piles, energy baffle walls, energy platforms, and introducing absorption pipes into tunnel segments can provide an alternative solution to cool tunnels and the surrounding ground, and transfer the resulting heat to neighbouring buildings for heating. This would also have the benefit of reducing energy consumption for tunnel ventilation. This article discusses the possibility of using waste heat from underground railway systems as a source of low-potential energy to provide heat to, for example, adjacent buildings. Various technologies for utilising waste heat from underground railway tunnels that have already been implemented or whose models are technically and economically feasible are presented.