First step for energy generation at the Dos Bocas Refinery
The gas turbine at the Cogeneration plant was cranked for the first time with fuel combustion, creating the “first fire”, both of which are the steps needed prior to the start of energy generation at the plant that will soon be supplying electricity to the entire Olmeca refinery, located in Paraíso, Tabasco.
In August, a key milestone was achieved in the start-up process at the Cogeneration plant of the Dos Bocas Refinery. These are the “crank” and the “first fire”, the initial tests required before the power generation process can begin.
Alejandro Maluf, Northern Area Director of Techint Engineering & Construction, explains that, “the ‘crank’ and the ‘first fire’ are a major milestone for us as this event underscores Techint's technical capabilities and commitment to project completion. This important achievement was possible thanks to the tireless effort and dedication of our exceptional work team.”
José Cárdenas Sepúlveda, Cogeneration Commissioning Manager, details that the first start-up reveals the technical capabilities of the system for energy generation. “On August 5, we achieved a key milestone for the Cogeneration project: we successfully completed the first fire, where the gas turbine is switched on and run on fuel at the site, culminating months of intense tests on the gas turbine and its auxiliary systems,” he explains.
With the first fire at Gas Turbine 1 of the plant, “the first run was held at 3,600 revolutions per minute at the first turbogenerator that will be providing electricity to the Dos Bocas Refinery during its operational life.”
The long-awaited “crank”
On July 26 work began to start up the so-called “crank”. Cárdenas Sepúlveda explains: “The starter motor is used to rotate the turbine at 820 revolutions per minute (crank speed). This is a process where we verify the vibrations and behavior of the machine, including the compressor, the combustion stage, turbine and electricity generator.” He goes on to say that, “After confirming the correct operation of the Gas Turbine 1 systems, the machine was rotated at a nominal speed of 3,600 revolutions as a result of the combustion of natural gas.”
After validating that the process was carried out correctly, the same crank procedure was repeated a few days later, followed by the ignition of the first fire.
“First fire”: the long-awaited milestone
It symbolizes the beginning of fuel combustion, a process which transforms the energy from the calorific value contained in the gas, to the mechanical energy of the spinning rotor which produces electricity. According to Cárdenas, when the turbine reaches 820 revolutions per minute, the speed is then reduced to 350, natural gas is introduced to ignite the process which then makes the turbine pick up speed, describing a curve until it reaches 3,600 revolutions per minute.
The manager indicates that it is so-called the “first fire” because “it’s the first time that gas enters the turbine’s combustion chamber and produces ignition”, meaning both fire and a high temperature in the turbine.
The “first fire” is crucially important, as it shows both that all the systems that need to interact are doing so correctly, and that mechanical completion has been achieved. This leads to the next step, which involves creating the conditions to close the machine switch, leading to the generation of electricity.
This is a key milestone, not only for Techint E&C, but also for the Dos Bocas Refinery and, ultimately, for the future of Mexico's energy sector. When operating at 100%, the turbines at the Cogeneration plant will have the capacity to produce over 340 MW of energy.