In 2015, a cogeneration plant was inaugurated in Monterrey, Mexico, to supply our client’s metallurgical and cardboard manufacturing facilities. With a power of 14.4 MW, it became a basic support for the different plants of the company. It is a combined heat & power plant designed with a combined cycle configuration, providing the necessary steam, as well as the electrical energy needed to power the paper mill and metallurgical plant that are part of the complex. AITESA was responsible for the supply and assembly of the heat recovery boiler. This boiler generates steam using the thermal energy contained in the exhaust gases from the gas turbine.

It is a natural circulation boiler that generates steam at two pressure levels (40 bar and 6 bar). It also has a 10 MW afterburner system, achieving a maximum production of 32.6 t/h of superheated steam at 400ºC and 40 bar pressure and 2 t/h of saturated steam at 6 bar. The boiler is composed of the following modules:

• High pressure superheater, whose purpose is to superheat the saturated steam.
• High pressure evaporator, where water evaporates at high pressure by natural circulation, with associated boiler.
• High pressure economizer, whose function is to preheat the water before it is introduced into the high pressure boiler.
• Low pressure evaporator, for the transformation of water into steam at low pressure with its associated boiler.
• High and low pressure economizer, where the feed water is preheated and distributed to both the low pressure boiler and the high pressure economizer.

In addition to the afterburner system and the modules described above, AITESA supplied the flue gas bypass valve for this project, as well as all the associated equipment for the correct operation of the boiler (feed pumps, continuous purge flash tank, purge cooling tank, steam silencers and all the associated instrumentation).

The company awarded the contract for the supply of the boiler and auxiliary equipment in June 2013, with delivery in 2014. The plant was commissioned during 2015 and continues to operate successfully.