Validation of Advanced Steam Turbine Technology: A Case Study of an Ultra Super Critical Steam Turbine Power Plant

High efficiency and flexible operation continue to be the major requirements for power generation because of the benefits of reduced emissions and reduced fuel consumption, i.e. reduced operating costs. Ultra super critical (USC) steam parameters are the basis for state of the art technology of coal fired power plants with highest efficiency. An important part of the development process for advanced steam turbines is product validation. This step involves more than just providing evidence of customer guaranteed values (e.g. heat rate or electric output). It also involves proving that the design targets have been achieved and that the operational experience is fed back to designers to further develop the design criteria and enable the next step in the development of highly sophisticated products. What makes product validation for large size power plant steam turbines especially challenging is the fact that, due to the high costs of the required infrastructure, steam turbine manufacturers usually do not have a full scope / full scale testing facility. Therefore, good customer relations are the key to successful validation. This paper describes an extensive validation program for a modern state of the art ultra supercritical steam turbine performed at an operating 1000 MW steam power plant in China. Several measuring points in addition to the standard operating measurements were installed at one of the high pressure turbines to record the temperature distribution, e.g. to verify the functionality of the internal cooling system, which is an advanced design feature of the installed modern high pressure steam turbines. Predicted 3D temperature distributions are compared to the actual measurements in order to verify and evaluate the design rules and the design philosophy applied. Conclusions are drawn regarding the performance of modern 3D design tools applied in the current design process and an outlook is given on the future potential of modern USC turbines.