Predicting energy-efficient effect of the controlled air delivery
at the Novo-Liuberetskie Wastewater Treatment Facilities

Summary

Стратегия развития АО «Мосводоканал» предусматривает
The corporate strategy of «Mosvodokanal» JSC envisages the systematic practical application of energy-efficient solutions substantiated by the method of mathematical prediction of the energy-efficient effect of the controlled air delivery at the air blower house of Block No. 1 of the Novo-Liuberetskie Wastewater Treatment Facilities in Moscow. The controlled air delivery to the aeration tanks for the biological wastewater treatment processes has been proposed as a key and cost effective method of energy conservation. The energy-efficient effect was determined by comparing the resultant energy consumption of two states of the predictable air deliver system – the basic state without control and controlled one. In the process of data and measurement method generation the calibrated metering devices of the operating SCADA system and data of the certified laboratory were used. The experimental survey of the air blower house with N750-23-6 units was carried out. The average decrease of air delivery resulting from the equipment deterioration for the 35 years’ operating period was 5.8–10.4%; the operation pressure decrease was 40.7–5.4%. The isoentropic coefficient of performance of N750-23-6 units was 75% at 79% rating. The method of predicting the energy-efficient effect including the mathematical model of energy input is considered. The model provided for 1.27% average ratio error at the verification against the actual environment of the operating object. The mathematical prediction of the energy-efficient effect revealed 32.5% or 11,343.97 thousand kWh/year reserve or 30,061.52 thousand ruble/year (VAT excluded) savings. Adjustable blade control of the air blowers was chosen as the technical basis of the energy efficiency. The study results formed the basis for the energy service contract.

Key words

energy efficiency , control arrangements , sewerage treatment facilities , simulation modeling , air-blowing house , rotary blade regulation , energy service contract , energy-efficient effect

Energy-efficient principle of upgrading the air blower house at the Samara municipal wastewater treatment facilities

Summary

As a key and economically advantageous measure on energy efficiency and investment return in the field of wastewater disposal «Samarskie Kommunal’nye Sistemy» Company approves the processes of air supply regulation at the municipal wastewater treatment facilities. A big complex of the air blower house has been designed and successfully implemented by improving the typical design projects for the RF conditions developed by SoiuzvodokanalNIIproject Institute for the estimated supply of 132 144 Nm³/h. The specific features of building and assembly works when installing 15 ton units under the conditions of the limited capacity of the hoisting equipment (9 tons) are set. The mechanical rotary blade principle of fan regulation was adopted as a basis of the energy saving solution. At the first implementation stage under the conditions of the lack of an operating automated process control system 26.1% reduction of the specific power consumption was recorded at the average specific power consumption of 22.39 kW/1000 Nm³. The engineering design reflects possible 45–100% regulation of air supply to the aeration tanks as well as its relation to the consumed power of 1273.2–2674.2 kW (for 20 °C input temperature, 50% relative humidity). Two-loop scheme of the automated control system for «aeration tank gate valve control unit – blower unit group» is presented. The analysis of the fan testing at the manufacturer’s factory is given. The parameters of regulating centrifugal air blowers by two control actions: of regulated diffuser at the outlet and inlet guide vane unit are presented. The mathematical method of recalculating the characteristics of air blowers with the use of the «degree of control» basic concept was developed and experimentally verified. The use of the method proves the wide range of the running characteristics of regulated units for all the year seasons, the mode of combined operation of one non-regulated and three regulated air blower units for the experimental work period.

Key words

reconstruction , energy efficiency , simulation modeling , air-blowing house , wastewater treatment facilities , rotary blade regulation