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Operation of a Prototype for Real Time Control of Pressure and Hydropower Generation in Water Distribution Networks

  • N. Fontana
  • M. Giugni
  • L. Glielmo
  • G. Marini
  • R. Zollo
Article

Abstract

Pressure regulation is the most common strategy for leakage reduction in water distribution networks (WDNs). The literature also offers many studies pointing to the benefits of coupling pressure regulation with energy production in WDNs. To this end, a turbine can recover the energy that is otherwise dissipated by the Pressure Reducing Valve (PRV). However, although numerical simulations developed for various sites show high potential revenues and attractive capital payback periods, to date there are very few field installations. The main difficulty is that flow and pressure vary continuously at the network inlet, thus requiring real time control (RTC) of the valves and turbine to ensure adequate service levels. A recent paper discusses the operation of a laboratory prototype, which is able to both maximize energy production and regulate pressure in a WDN, with an optimization algorithm identifying the optimal operation of valves and turbine, commanded in real time according to the network operation. Because the earlier paper mainly discusses the theoretical framework of the optimization problem supported only with preliminary experiments, the present paper presents extensive laboratory experiments and analysis demonstrating the prototype’s ability to both regulate pressure at the critical node of the WDN and maximize power generation, in any operating condition. The results were also compared with theoretical values, showing very good agreement in all cases.

Keywords

Water distribution networks Hydropower generation Pumps as turbines Real time control 

Notation

D

Impeller diameter

g

Gravitational acceleration

Hd

Head downstream of the prototype

HT

Head drop through the turbine

Hu

Head upstream of the prototype

n

Rotational velocity of the impeller

nopt

Optimal velocity of the impeller for hydropower generation for HT < Hu-Hd and Q2 = Qtot

opt

Optimal velocity of the impeller for hydropower generation for HT = Hu-Hd and Q2 = Qtot

opt

Optimal velocity of the impeller for hydropower generation for HT = Hu-Hd and Q2 < Qtot

OD

Opening degree of a PRV

ODmax

Maximum allowed opening degree of a PRV

ODmin

Minimum allowed opening degree of a PRV

OD1

Opening degree of the by-pass line PRV

OD2

Opening degree of the generation line PRV

PT

Generated power

Q

Flow discharge

Qopt

Optimal flow discharge for hydropower generation for HT < Hu-Hd and Q2 = Qtot

opt

Optimal flow discharge for hydropower generation for HT = Hu-Hd and Q2 = Qtot

opt

Optimal flow discharge for hydropower generation for HT = Hu-Hd and Q2 < Qtot

Qmin

Minimum flow discharge for hydropower generation

Qtot

Flow discharge entering the prototype

Q1

Flow discharge running the by-pass line

Q2

Flow discharge running the generation line

t

Time

γ

Fluid specific weight

η

Turbine efficiency

π

Power number

πopt

Optimal power number for hydropower generation

ρ

Fluid density

φ

Flow number

φopt

Optimal flow number for hydropower generation for HT < Hu-Hd and Q2 = Qtot

φ̅opt

Optimal flow number for hydropower generation for HT = Hu-Hd and Q2 = Qtot

φ̂opt

Optimal flow number for hydropower generation for HT = Hu-Hd and Q2 < Qtot

ψ

Head number

ψopt

Optimal head number for hydropower generation for HT < Hu-Hd and Q2 = Qtot

ψ̂opt

Optimal head number for hydropower generation for HT = Hu-Hd and Q2 < Qtot

ΔHi

Head loss through the i-th valve

ΔHN

Head loss between the node downstream of the prototype and the critical node

Notes

Compliance with Ethical Standards

Conflict of Interest

None.

References

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Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.Dipartimento di IngegneriaUniversità degli Studi del SannioBeneventoItaly
  2. 2.Dipartimento di Ingegneria Civile, Edile e AmbientaleUniversità degli Studi di Napoli “Federico II”NaplesItaly

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