DESIGN OF A LOW WIND SPEED WATER PUMP

ABSTRACT;

The low wind speed water pump utilizes wind energy to draw water. The main parts in this project are rotating blades, gear and wheel setup, cylinder and piston arrangement, one way valves, suction, delivery pipes, foot valve and wind direction pointer. A foot valve is connected at the end of the suction pipe. Inside the foot valve there is a one-way valve that is closed when the piston moves up and opens when the piston moves down thus there is an alternate flow of water in the delivery pipe. A low wind speed water pump is best recommended in arid and semi-arid lands. This is majorly because these areas have reliable low wind speeds which are a cheap source of energy. Use of diesel as an alternative is expensive due to the high transport costs. Since the low wind speed water pump uses no electric power and fuel but instead uses freely available wind energy, it is cheap and best for these off-grid regions.

In the design of the low wind speed water pump, we used a horizontal axis windmill with 25 blades. Each blade had a radius of 1.5 m giving a total surface area of 0.5585 m2 and this gives a solidity of 0.8033 which meets the required optimum value for windmills. The torque output of the windmill is 2130.06 Nm thus it is sufficient to sustain the desired flow rate of 0.1736 x 10-3 m3/s with a maximum head of 100m and also overcome other barriers to motion such as friction.

Generally, we considered the designing of the turbine rotor and pump so that the pump size, are matched to the total head. Therefore, the blades were able to produce sufficient torque in order to raise the water to the required level. The blades of the windmill were designed for low start up winds (4m/s).