Valve dynamics in multi-cylinder positive displacement pump model

Pumps are critical components of many industrial processes. Although they vary in size, depending on the application, their operating principles and performance parameters are similar across generic families. Large industrial positive displacement (P.D.) pumps, primarily used in mining, oil and gas industries, deliver significant amounts of flow coupled with very high pressures. However, increasing energy costs and sustainability concerns demand systems re-design to improve their efficiency. Most established forms of PD pumps have duty cycles fixed by the movement of spring loaded valves. One approach to increase their energy efficiency could be to dynamically vary the movement of these valves. To test this hypothesis and quantify any potential benefits a computational model is required. This paper introduces modelling technique used to analytically describe a multi-cylinder positive displacement pump. A hybrid modelling approach is described which incorporates analytical relationships, the results of CFD simulation and experimental values. Results show how different valve actuation responses affect the overall flow rate of the pump. The results presented in the paper clearly indicate future development steps for improved control of positive displacement pumps.