Francis turbines designed for generating electricity with an efficiency exceeding 90% are suitable for heads between 20 and 700 meters.
With about 60% of the global hydropower capacity in the world, Francis turbines are the most widely used type of hydro turbine. GE has continuously invested in R&D to increase turbine efficiency and developed specific product enhancements to improve machine performance. GE has successfully completed numerous installations of Francis turbines with outputs up to 800 MW, including one of the largest Francis turbines ever made - each with a runner diameter of 10 meters and weighing over 450 tons. The result of our focus on product evolution, GE developed the ring gate solution, a cylinder that moves between the stay vane and the guide vanes that can replace the traditional butterfly or spherical valves. A critical mechanical component of hydro power plants, our bearings include the most up-to-date technologies:. * Water bearings that increase overall efficiency, are environmentally-conscious and minimize operating costs. Older hydropower plants benefit directly from our ongoing efforts to increase the efficiency, output, and safety of our Francis turbines.
# Francis turbine. Francis inlet scroll at the Grand Coulee Dam. Side-view cutaway of a vertical Francis turbine. Here water enters horizontally in a spiral-shaped pipe (spiral case) wrapped around the outside of the turbine's rotating *runner* and exits vertically down through the center of the turbine. The **Francis turbine** is a type of water turbine. Francis turbines are the most common water turbine in use, and can achieve over 95% efficiency. A wicket gate "Wicket gate (hydraulics)") around the outside of the turbine's rotating runner controls the rate of water flow through the turbine for different power production rates. Francis turbines are usually mounted with a vertical shaft, to isolate water from the generator. The Francis turbine is a type of reaction turbine, a category of turbine in which the working fluid comes to the turbine under immense pressure and the energy is extracted by the turbine blades from the working fluid.
By integrating both turbine types in a micro-hydro system, the overall efficiency can be maximized by selecting the appropriate turbine for given conditions—
This technology allows for the speed of the runner to be adjusted in order to maximize the efficiency and/or reduce dynamic loads of the turbine
The proposed method aims to improve the hydraulic performance of the turbine, enhance and suppress the vibration of the turbine, and expand the operation range of the turbine on the basis of the actual situation given that Francis turbine frequently operates in low- and ultralow-load areas under the condition of multi-energy complementarity and continuous adjustment of operating conditions. The super-transfer approximation method was used to select the weight co-efficient of water turbine operating conditions, and a multi-objective optimization function with the efficiency and cavitation performance of the water turbine as optimization objectives was constructed to ensure that the optimized water turbine can achieve the optimal performance in the full working condition range. A multi-objective and multi-condition optimization design method for Francis turbine runner based on the super-transfer approximation method is proposed in this work to improve the hydraulic performance of the turbine in the full working condition range and broaden the working range of the turbine given that the Francis turbine frequently operates in low- and ultralow-load areas under the condition of multi-energy complementarity and continuous adjustment of operating conditions.
70 U.S. DEPARTMENT OF ENERGY OFFICE OF ENERGY EFFICIENCY & RENEWABLE ENERGY | WATER POWER TECHNOLOGIES OFFICE Project Objectives: Expected Outputs and Intended Outcomes Outputs: • Reports demonstrating the flexibility potential of low head Francis hydropower plants – Methodology to tackle this potential – Example on a typical plant, High Rock • Recommendation of operating range extension on High Rock plant • Quantification of grid benefit from increased flexible capabilities of Francis-driven hydropower plants Outcomes: • Headroom almost doubled for High Rock site • Simulation of the improved grid frequency response from low head Francis unit extended flexible capabilities • The plant owners aware of this potential and the tools to tackle it… so that they integrate range extension analysis in their investment forecasts • The regulators & public authorities will be aware of this potential… so that they acknowledge the related value in the regulatory context and support technological improvements for a wider dissemination (other plants/head/size…) 71 U.S. DEPARTMENT OF ENERGY OFFICE OF ENERGY EFFICIENCY & RENEWABLE ENERGY | WATER POWER TECHNOLOGIES OFFICE Project Timeline FY 2020 Prepare… FY 2021 Implement & interim conclusions FY 2022 Final analysis & conclusions Prepare measurement campaigns on site (T2.1) Develop temporary advanced condition monitoring system (T2.2) Prepare model test (T5.1) Site measurement campaign on mature runner (T3) 1st advanced site measurement campaigns on retrofitted runner (T4) • 1st preliminary range extension analysis Temporary advanced condition monitoring system implemented on-site (T4) 1st advanced site measurement campaigns on retrofitted runner (T4) Numerical simulation completed (T6.1/2) Grid impact model completed (T7) • 2nd preliminary range extension analysis 1st dissemination actions @CleanCurrents and @CEATI conferences Model test completed (T5) Damage model completed (T6) Grid impact simulation completed (T8) • Final range extension analysis • Grid impact conclusions Dissemination actions @HydroVision Intl and @CEATI • Project is globally successful and achieved the expected goals • Some difficulties that led to a 6-month project extension – Manage developments
High – efficiency Operation: The high – efficiency energy – conversion ability of the Francis turbine directly contributes to cost reduction.