CMI ENERGY - Horizontal and Vertical Heat Recovery Steam Generators

CMI, Cockerill Maintenance & Ingénierie (Belgium), traces its roots back to 1817. Strategic growth and acquisition over the years, including the purchase of EPTI in North America in 2004, have continued to position CMI Energy as a leader in HRSG technology. CMI ENERGY is a sector of the CMI Group, and is the 3rd supplier in the world of Heat Recovery Steam Generators (HRSG) for application behind gas turbines.

Since its first project in 1966 - a fired boiler behind an early gas turbine model at the Angleur Power Station near Liege - CMI Energy has supplied more than 300 vertical HRSGs, mainly for combined cycle power plants, and more than 200 horizontal HRSGs, bringing the total of both designs - horizontal and vertical - to over 500 references globally.

HORIZONTAL GAS PATH HRSG

The horizontal HRSG design was developed to meet the requirements of North American operators and is suited for cyclic operation. Most of the plants with CMI Energy horizontal HRSGs commonly operate with weekly or even daily starts.

In most recent advances to the technology, the horizontal design was updated to accommodate the large gas turbine with the development of a 3-wide design. Improvements and optimization of the design was conducted to maintain high levels of shop assembly, quality, and simplification of field construction. This enhancement allows for competitive application behind all sizes of gas turbines.

VERTICAL GAS PATH HRSG

The vertical HRSGs are drum type designs with natural circulation. Circulating pumps used in early generation vertical units have now been replaced by a thermosiphon circulation method which retains operating flexibility and eliminates the need for the circulating pumps under any mode of operation.

Since creation of some of CMI’s earliest units, the vertical HRSG has supported the company’s reputation for reliable cyclic operational duty. These units address user demand for a combined cycle component that operates effectively in any situation from base-load to peak-load duty during each unit’s entire life span.

High pressure superheater drainage is very fast and complete during the gas purge which precedes a warm or hot start. This feature is important since it avoids the build-up of stresses which can lead to metal fatigue and, subsequently, to tube leaks.

All headers and return bends are located outside the direct gas path. This allows for direct access for inspections and maintenance without any scaffolding. This feature makes possible a very high availability factor.

HRSG CONSTRUCTION

All CMI Energy HRSGs employ a modular construction approach with a high degree of factory assembly for good quality control. Modular construction assures that site welds on heat exchanger pressure parts are kept to a minimum. On site, erection of the modules for the vertical design does not require cranes: all modules are lifted to their final position via an innovative hydraulic lift mechanism.

HRSG EXPERIENCE

Since the first CMI order received in 1966, CMI has incorporated many "first time" technical innovations in the design. Such "firsts" have helped establish CMI Energy as a pioneer in HRSG design and application.

AFTER SALES SERVICE - MAINTENANCE EXPERTISE

CMI Energy includes a strong servicing organisation with many local branches in Europe, the Middle East, South East Asia and North America. CMI Energy After Sales supports power generation activity around the world with diagnostics, inspections, procedure analyses, equipment upgrades, parts supply and urgent technical and field interventions services for HRSGs from all suppliers.