Application of Multi-Dimensional Hill Chart in the Condition Monitoring and Cost Estimation of the Francis Turbine Unit

With a large-range-operation head, the Francis turbine unit is the most widely used type of hydraulic turbine in the world. The general range of the Francis turbine is 20–700 m. Because of this, the operating stability of the Francis turbine needs to be focused on. In this paper, a multi-dimensional hill chart is applied to a low-head Francis turbine unit to describe its vibration characteristics. Firstly, a field test was conducted on the unit in order to obtain vibration data under different operating conditions. Secondly, the condition indicators were calculated and extracted from the experimental data. Then, the condition indicators under different head values and outputs were fitted to form a multi-dimensional hill chart. In the end, the vibration characteristics of the researched low-head Francis turbine unit were analyzed based on the multi-dimensional hill chart.