Dynamic and seismic analysis of the 2^nd HA energy plant in Mexico

A new combined cycle plant is being built in Jalisco, Mexico by Tecnicas Reunidas, a Spanish engineering firm which has designed and constructed more than 1000 industrial plants in over 50 countries.  This combined cycle plant is slated for completion in December 2019, and will house two General Electric (GE) 7HA.02 gas turbines, two generators, two heat recovery generators and one steam turbine, with a total electricity output of 875 MW.

This new state-of-the-art plant is expected to improve the state grid by using the highest levels of efficiency in the industry, and providing more affordable and yet more reliable power to the residents. It is also expected to generate enough power equivalent to supplying up to 2.8 million average Mexican homes.  The plant will be operated by Fisterra Energy, and will operate exclusively under the new wholesale electricity market created by Mexico’s energy reform.

Dynamis Mission

As the new Tierra Mojada combined cycle plant is located in the state of Jalisco, which is an earthquake-prone area, TR has enlisted Dynamis Associates to perform the seismic hazard analysis for the entire power plant, and the vibration analysis as well as the seismic analysis of the GE steam turbine pedestal.

The turbine-generator foundation is a complex engineering structure.  Dynamic behaviors of the foundation play an important role in providing normal operating conditions for the supported turbo-machine. Dynamis has performed a vibrational analysis that consists of evaluating the dynamic flexibilities at each bearing position for vertical and horizontal direction, calculated for the frequency range from the 90% to 110% of the nominal speed 60Hz.  Such calculations were performed in the frequency domain with a new approach that allows to take into account the frequency-dependent character of the soil reaction.  Dynamis has also performed the seismic design of the pedestal, ensuring that the turbine will be capable of withstanding up to 0.4g accelerations.