Previous Issues

ABSTRACT

A computer implementation is presented to analyze irrigation networks with sprinkler systems and to select the most economical pump among a wide range of variable-speed vertical turbine pumps. The program output consists of a network analysis, a system demand curve, a list of the infeasible pumps with the reason for rejection, and a list of the feasible pumps. The feasible pumps are listed in ascending order with respect to their input power. The selection of the pumps can be based on a range of pump rotational speeds rather than a single speed. An application example based on a real-world data is presented. The program has a built-in database that contains characteristic curves for about 100 different vertical turbine pumps obtained from international pump manufacturers. The user can modify the database and can deactivate or activate the available pumps in the database. Using the computer program, the effect of pump rotational speed on the pump selection is studied. It is found that the rotational speed is a very important factor to consider when selecting a pump. A pump with the least input power at a given rotational speed may become among the worst pumps at another rotational speed for the same application. Furthermore, it is found that as the number of rotational speeds considered increases, the chance of selecting the pump with the optimal operational cost increases.

Keywords: Irrigation systems; pump selection; turbine pumps; vertical pumps.

The program developed  in this study is available from the author at no cost.