Abstract
The power generating industry is faced with high water consumption and poor water performance leading to failure in managing water networks. Extensive amount of water is required for the generation of electrical energy hence the energy sector is ranking the highest in global freshwater consumption. The South African environmental and forestry industry ministry has put strict restrictions on the thermal power plants water usage norms, compelling power stations to reduce the water consumption from 3.5 to 2.3 π3/ππβ and achieve the zero liquid discharge. A quantitative research methodology was followed to conduct this study. A mass balance approach was followed to investigate and analyse the water losses in a power station with the objective to optimize the steam-water cycle. A water consumption of 0.06 π/πΎπβ was measured versus the target vale of 0.02 l/kwh in one of the scenarios analysed. It was also found that when draining the boiler approximately 1.352 ππππ π is discharged into the effluent dams. The plant design configuration allows for the water lost through the drainage system to be recovered via the water treatment plant (WTP) however due to the high losses experienced; the drains are routed to the effluent handling dams. Four options were considered with the objective to optimize the demineralized water re-use. A decision matrix was done, and from the four options the boiler blowdown vessel (BBDV) recovery option scored highest and was therefore the identified as the technically fit, easy to integrate with a higher efficiency solution.
Keywords β Steam-water cycle, Demineralised Water, Optimization.