This is the best book on the design, manufacture and operation of small Pelton wheel hydro systems currently available. Written by a practical engineer with extensive experience of small hydro systems, it is aimed at readers with some technical/engineering background who nevertheless have no special knowledge of hydro systems and need detailed information. It goes far beyond the elementary treatment found in most standard hydraulics or fluid-mechanics textbooks.
It first deals with the history of hydro power, and reviews various types of small hydro system. Pelton turbine selection is considered next, covering (with several worked examples) the choice of both single and multi-nozzle, vertical- and horizontal-axis options. The basic and improved 3-dimensional flow theories needed for estimating losses and designing nozzles, spear-valves, Pelton wheel buckets and runners, the casing and tail-race are then all presented, using formulae derived the appendices. The main (55 page) section on design then follows, giving optimised recommendations for the bucket profile and its attachment to the runner, as well as comprehensive data and practical recommendations on materials and manufacturing methods. Detailed mechanical and structural design guidelines are also provided, covering mechanical loading, strength calculations, welding, joints, shafts, bearings, seals, generators and load-control systems. There follows a section dealing with practical manufacture, aimed particularly at those with limited facilities (the author's experience was mainly in developing countries with only basic resources). He discusses casting and welding techniques, bolted, welded or one-piece runners, balancing, shaft-runner hub joints (including Ringspann-type locking assemblies), housings and bearing assemblies. The final two sections deal with installation and commissioning, maintenance and problem-solving.
The book is completed by six detailed and very useful appendices: Notation, units and conversion factors (the main text uses SI units throughout); derivation of formulae; full system calculation spreadsheet; O'ring seals; keys and keyways; limits and fits and specific speeds. There follows a 63-item list of references to the primary source material upon which the book is based, a glossary of terms and a detailed index.
With the help of this book, a reader with basic technical/engineering training has all the information needed to design and have manufactured a small Pelton-wheel hydro system. Alternatively, he/she can confidently engage in informed and detailed discussions with potential suppliers, knowing just what questions to ask and where the potential problems lie, or evaluate whether an available second-hand unit is likely to be suitable. My only criticism is that I think the section dealing with the selection of generators and load control systems is a bit 'thin'. It is equally important to be able to make fully-informed choices in this area as well. But with that tiny reservation, I recommend this book unreservedly.
4 people found this helpful.
Was this review helpful to you?