﻿ Calculation of Efficiencies at flows above peak efficiency flow of Francis turbines by RETSCREEN® ENGINEERING & CASES TEXTBOOK

# Calculation of Efficiencies at flows above peak efficiency flow of Francis turbines by RETSCREEN® ENGINEERING & CASES TEXTBOOK

 1 Specific speed based on flow：nq - 2 Design flow：Qd m^3/s Qd＞Qp 3 Runner throat diameter：d m - 4 Coefficient：Rm (default = 4.5) Turbine manufacture/design coefficient 5 Flow：Q m^3/s Q＞Qp 6 Graph x-axis:nq,y-axis：eq x-axis:Qd,y-axis：eq x-axis:Q,y-axis：eq Plot Input Data： YesNo 7 Number of gridlines of Graph x-axis, y-axis -
:Export Graph Image.

## Keyword

Efficiencies at flows above peak efficiency flow, Drop in efficiency at full load and Efficiency at full load,Efficiencies at flows below peak efficiency flow,Peak efficiency flow,Turbine peak efficiency,Runner size adjustment to peak efficiency,francis turbines,specific speed based on flow, Runner throat diameter,turbine manufacture/design coefficient

## Reference

[1]：RETScreen® International『CLEAN ENERGY PROJECT ANALYSIS：RETSCREEN® ENGINEERING & CASES TEXTBOOK SMALL HYDRO PROJECT ANALYSIS CHAPTER』.pp.37-51.

## Remarks

・^ep：『Drop in efficiency at full load』(Reference[1])
・eq：『Efficiencies at flows above peak efficiency flow』(Reference[1])
・Qp：『Peak efficiency flow』(Reference[1])
・Qd：『design flow(flow at rated head and full gate opening in m^3/s)』(Reference[1])
・ep：『Turbine peak efficiency』(Reference[1])
・Rm：『turbine manufacture/design coefficient(2.8 to 6.1; default = 4.5).』(Reference[1])
・^ed：『Runner size adjustment to peak efficiency』(Reference[1])
・^enq：『Specific speed adjustment to peak efficiency』(Reference[1])
・nq：『specific speed based on flow』(Reference[1])
・d：『runner throat diameter』(Reference[1])