Comparative evaluation of flow-through and counter-flow indirect-evaporative air coolers and their influence on the heat balance of transformer underground substations

Abstract

In order to optimize the air environment temperature of the underground engineering equipment premises, it is necessary to conduct a comparative assessment of the operation of flow-through and counter-flow indirect-evaporative air coolers. Based on the previous mathematical models that describe the thermophysical processes in the channels of indirect evaporative coolers, an analysis of the structural and standard parameters of their operation is carried out. The most rational ratios of flows through the “wet” and “dry channels” are revealed and they ensure the maximum station cooling capacity. The transformer substation of the underground illustrates the effectiveness of their use. According to a result of the studies, it has been proved that the most rational ratio of air flows through wet and dry channels for flow-through indirect-evaporative coolers is 2.1-2.2, for counter-flow heat exchangers it is 3.0. The advantage of recuperation coolers is established by such indicators as: cooling capacity - 53.5%, air cooling range - 41%.