Demystifying the use of cogeneration in mine cooling applications

摘要

This paper deals with the results of a study conducted at the end of 2009 about the application of cogeneration using diesel generators for large mine cooling installations on South African mines. A total owning cost comparison has been carried out between a conventional mechanical vapour-compression system and the above-mentioned cogeneration system, taking into account both capital and operating costs. A sensitivity analysis lias also been conducted for different fuel prices and electric power scenarios. The design calls for 15 MW(R) of installed cooling capacity, which requires about 15 MW of diesel generating electrical power using some 37,500 kW of fuel thermal power. The proposal was to install four 3.75 MW diesel generators to help produce some of the electric requirements of the mine and use the exhaust gases and the water from the jacket-coolers to drive four single-effect lithium-bromide and water (LiBr-water) absorption refrigeration machines, each with a cooling capacity of 3.75 MW(R). This would in turn reduce to almost zero the power that otherwise would be required to drive the ammonia mechanical refrigeration units with the same equivalent cooling capacity.