Flow rate measurements in hydropower plants using the pressure-time method - Experiences and improvements

摘要

One of the most difficult tasks in the performance tests of hydraulic machines (turbines and pumps) is related to measuring the flow rate (discharge). Particularly, this problem concerns the large-size structures, which can be found in hydropower plants. In such cases, flow rate measurement is difficult and expensive due to the need to use special measuring devices assuring sufficiently low uncertainty level of measurement results in structures of such sizes, complex geometry, difficult access to the measurement cross-sections, etc. Only a few methods fulfilling this requirement are available under the conditions occurring in hydropower plants. One of them is the pressure-time method (known as the Gibson method) which is primary method of flow rate measurement particularly used in hydropower plants equipped with large-scale derivation.