This Guide serves to: a) present data on hydro-abrasive erosion rates on several combinations of water quality, operating conditions, component materials, and component properties collected from a variety of hydro sites; b) develop guidelines for the methods of minimizing hydro-abrasive erosion by modifications to hydraulic design for clean water. These guidelines do not include details such as hydraulic profile shapes which should be determined by the hydraulic design experts for a given site; c) develop guidelines based on “experience data” concerning the relative resistance of materials faced with hydro-abrasive erosion problems; d) develop guidelines concerning the maintainability of materials with high resistance to hydro-abrasive erosion and hardcoatings; e) develop guidelines on a recommended approach, which owners could and should take to ensure that specifications communicate the need for particular attention to this aspect of hydraulic design at their sites without establishing criteria which cannot be satisfied because the means are beyond the control of the manufacturers; f) develop guidelines concerning operation mode of the hydro turbines in water with particle materials to increase the operation life; It is assumed in this Guide that the water is not chemically aggressive. Since chemical aggressiveness is dependent upon so many possible chemical compositions, and the materials of the machine, it is beyond the scope of this Guide to address these issues. It is assumed in this Guide that cavitation is not present in the turbine. Cavitation and hydro abrasive erosion may reinforce each other so that the resulting erosion is larger than the sum of cavitation erosion plus hydro-abrasive erosion. The quantitative relationship of the resulting hydro-abrasive erosion is not known and it is beyond the scope of this guide to assess it, except to recommend that special efforts be made in the turbine design phase to minimize cavitation.
Number of pages: 79
Date of approval: 2019-03-18
EN IEC 62364:2019 IDTIEC 62364:2019 IDT