Effect of Water Temperature on Centrifugal Pumps Performance under Cavitating and non-cavitating Conditions

The effect of water temperature on performance and cavitation inception of a centrifugal pump has been studied experimentally. A special test rig with a testing centrifugal pump was constructed in the laboratory of fluid mechanics at Higher Institute of Engineering - Hoon. The rig was designed so that the flow rate ratio, suction pressure, rotational speed and water temperature could be varied independently. The temperature and speed were varied from 15°C to 60°C, and from 1800 rpm to 2800 rpm respectively, while the ratio of flow rate to optimum flow rate was varied from 0.245 lit/sec to 0.767 lit/sec. The results showed that the pump head and pump efficiency increase with the decrease of water temperature. The results showed that increasing water temperature speeds up cavitation. The inception net positive suction head (NPSHi) was found to increase with the increase of temperature up to a maximum value and then decreased again.