Investigation of pre-cooling with Munters media for air-cooled geothermal power plants performance enhancement

Many binary-cycle geothermal power plants are air cooled due to the lack of water source. The performance of air-cooled geothermal power plant will experience a loss in production during hot seasons, at which a high demand for electricity happens. This paper describes an investigation of pre-cooling with Munters CELdek7060 to enhance summer performance. A case study of a proposed 29MWe binary-cycle geothermal power plant located in southwest Queensland was conducted. The plant was cooled by a 100m height Natural Draft Dry Cooling Tower (NDDCT). Two thicknesses of Munters CELdek7060 were employed to pre-cool the tower, i.e., 0.1m and 0.15m. The hourly performance of the proposed plant incorporated with pre-cooled NDDCT was compared with that of un-cooled tower in a typical hot and dry day. Results show that geothermal power plants cooled by NDDCTs can benefit from pre-cooling with Munters CELdek7060 during hot and dry days. The 0.15m-thick CELdek7060 offers slightly better improvement than the 0.1m-thick counterpart. The largest increment of power output happens at around 3p.m. at which the increment can be up to 80%. Moreover, the two pre-cooled towers consume approximately half of wet cooling tower water consumption.