Theoretical Study of the Behavior of a Hydraulic Ram Pump with Springs System

摘要

A new type of hydraulic ram pump, called Raseta pump, was invented, patented and crafted in Madagascar. The peculiarity of this hydram pump over conventional ones is that there is a spring in each of the waste and delivery valves. In addition, the usual air balloon is replaced by a balloon with 4 springs. Thus, this paper aims at theoretically studying the behaviour of this hydram pump equipped with a system of springs. For that purpose, a model associated with the studied hydram pump was developed and coded on Matlab. Then, a global sensitivity analysis was carried out for identifying the most influential parameters of this model while successively considering as the surveyed model outputs: the amount of wasted water, the amount of pumped water and the efficiency of the pump. As results, the most dominating parameters are relatively the same as those found by previous works on the conventional hydram pump without springs: height of the water column in the delivery pipe, the height of supply tank, the weight of the waste valve, and the length of the waste valve stroke. However, there are 3 other parameters that the present study exceptionally found as among the most influential ones as well, namely: the stiffness of the spring in the waste valve, the modulus of elasticity of the fluid, and the radius of the waste valve disk. In addition, similar to the case of air balloon, the effect of the spring balloon is not relevant. An extension work could be a techno-economic investigation of a pump system constituted by a number of hydram pumps similar to the one studied here for increasing water head in a pico hydropower plant.