Interactions of ground source heat pumps with nearby underground railway tunnels in an urban environment

Ground source heat pumps (GSHPs) can provide an efficient way of heating and cooling buildings due to their high operating efficiencies. The implementation of these systems in urban environments could have further benefits. In such locations the ground source heat is potentially more accessible through alternative sources such as through underground railways (URs). The heat from the ground surrounding an UR tunnel could be exploited to enhance the operation of GSHPs operating in heating mode. To achieve this, the interactions of GSHPs with neighbouring URs must be fully understood and there is little exploration of these in current literature. To address this, a numerical investigation was set out for a better understanding of such interactions. This preliminary model developed in this paper is highly simplified to enable rapid analysis of the system to establish key phenomena for more detailed additional research. The initial results clearly demonstrate that interactions occur between URs and neighbouring GSHP installations.