Feasibility of air blower house construction on the basis of life cycle costs evaluation

Summary

The demand of the wastewater treatment facilities for the controlled air-blowing equipment with a significant energy saving potential has been growing. Therefore the design concepts based on this type of equipment are attracting the investor’s interest. The aim of the study is economic analysis of the technologically controlled and uncontrolled air supply options for aeration systems of aeration tanks under the conditions of a newly built pumping-air blower house with and without account of the project investment attractiveness. Conditionally prescribed irregularity of air supply to the pneumatic aeration systems has been taken as a reference condition. The research method is economic analysis of the life cycle costs (LCC) including and without including the mechanism of time-variable cost adjustment, i. e. bank interest and inflation. Three options of an air-blowing house design are presented: without process control (multistage); with controlled electric drive (multistage); with the rotating-blade mechanism control (single-stage). During the construction of air-blowing houses the option with the introduction of single-stage rotating blade turbo blowers with dual control is most attractive. This option provides for the lower LLC index compared to the option of using a controlled electric drive for 23.07% – in case
the cost estimates do not include inflation and discount; and for 21% – in case the cost estimates use the mechanism of time-variable cost adjustment (with account of inflation and discount).

Key words

aeration system , air-blowing house , air blower control , economic analysis , life cycle costs , project investment attractiveness