In the area of the power machinery analysis, we have many years of experience in numerical FEM modeling of electrical generators and their components. We perform finite element analyses (FEA) of rotor as well as stator parts of the generators between 150 MW and 2500 MW. For these components, we focus on evaluation of the static strength, fatigue life as well as the crack propagation resistance. Based on the performed calculations we propose design modifications in order to fulfil the code requirements and/or meet the customer needs.
Another important branch of our activity in the power machinery area is analysis of components for nuclear power plants. We perform ASME Code qualification for the parts of the primary loop pressure vessels and other components. Our calculations include evaluation of the static strength and more importantly evaluation of the fatigue life where the components are qualified for 60 years of operation. We participate on development and qualification of the Westinghouse AP1000 nuclear power plant.
We are also engaged in the area of analysis of turbomachinery. In this branch, we provide thermo-mechanical analyses of different parts as well as entire assemblies. Our calculations are focused on the temperature distribution and subsequently on the thermo-mechanical loading of the turbine housings, turbine wheels, compressor and bearing housings. These calculations are followed by estimation of the operational life (low cycle – thermo-mechanical fatigue). We also perform evaluations of deformations in order to ensure no leakage, bolted connection evaluations, vibration analyses, etc.
As other examples in the area of the power machinery, we can mention thermal-stress analysis of the combustion boiler part, thermal analysis of the hot ashes cooling, and stress analysis of the fuel tank for the diesel generator.
Design of the electrical generator rotor must guarantee high reliability. For this reason, a detailed structural evaluation of each rotor part has been performed. As a result, a stress and strain distribution for each loading case has been obtained. These results were then used for the operational life assessment with respect to the material fatigue.
As part of the reactor vessel closure head replacement, a new component qualification must be performed. Thermal transient analyses of all operational conditions have been performed. Subsequently, structural calculations have been made considering nonuniform temperature distribution, pressure loading and other mechanical loadings. Finally, the fatigue life has been evaluated and ASME Code qualification has been completed.
For the combustion product storage tank, a thermal transient analysis of the hot ashes cooling has been performed. The results of this analysis were determination of the cooling history and reached ashes temperature after requested time.
Compressor housings are tested for the over-pressure condition. Before the actual test, a finite element numerical analysis (FEA) of the critical stresses and safety factor assessment has been performed. This numerical simulation allowed to reduce the number of required tests and minimize the risk of failure during the pressure test.
Electrical resistance causes high losses during generation and transportation of the electrical energy. A potential solution is to use superconducting materials. We have been providing a complete support to our customer and his innovation team during development of such electrical generator. We have been performing thermal, structural and some dynamic analyses for all parts including those in cryogenic environment. We are co-authors of US patent 9293959.