Ground-heat source: Alternative way of heating natural gas following Joule-Thomson pressure-reductions in supply pipes

Abstract

The Joule-Thomson reduction of temperature, which natural gas experiences when it undergoes a deliberate pressure-reduction in passing from the national grid to a local supply-line, can be compensated for by heat conducted from the soil surrounding the buried outlet pipeline. The rate of this heat transfer is dictated primarily by the surrounding soil's thermal diffusivity, but is relatively insensitive to the external diameter of the pipe, i.e. it increases only marginally with the area of the pipe-soil interface. Thus it is concluded that the heating of the relatively cold gas may be accomplished by requiring it to flow through a network of parallel well-displaced small-bore buried pipes.