Rapid Steam Turbine Replacement

Mechanical Dynamics & Analysis (MD&A) completed a comprehensive and rapid steam turbine replacement project in record time after the unit experienced a catastrophic failure event, requiring the replacement of the entire steam turbine and auxiliaries.

THE CHALLENGE:   The subject power plant is an important electrical generating facility in the country it is located within.  Returning the unit to service in the shortest possible time was critical for the turbine owner to provide its customers with a reliable supply of electricity.  A typical replacement period for a steam turbine of this design is approximately two (2) years.  Having the steam turbine offline for that long would have a severe impact and as such, MD&A was called upon to develop an alternative plan to bring the replacement steam turbine online sooner.  In addition to the time challenge, there were additional logistical constraints associated with transporting, installing, and repairing large power generation equipment within the subject country.

MD&A’s SCOPE:  MD&A was awarded turnkey scope of supply and installation of the steam turbine and auxiliaries. MD&A’s scope included replacing the steam turbine and installing a new control system, as well as a comprehensive rebuild of all steam turbine valves and actuators and installing a new hydraulic power unit.  MD&A also provided turnkey installation, start-up support, and all project management.

THE SOLUTION:  MD&A in conjunction with its parent company, Mitsubishi Power, developed a customized plan to complete manufacturing and installation within one (1) year of the project start date.  The key elements of this successful plan included reducing manufacturing lead time, coordinating equipment shipping, utilizing MD&A’s extensive in-house capabilities, and overall extensive project management and planning.

Manufacturing lead time was significantly reduced through Mitsubishi Power working closely with their suppliers for rotor forgings and shell castings.  Mitsubishi Power also expedited manufacturing activities within their factory as well.

Shipping logistics were streamlined with over 300 tons of equipment flown from the factory via charter aircraft in five (5) carefully coordinated flights.

By utilizing MD&A’s extensive in-house capabilities, the MD&A Project Team was able to maintain control of the schedule more effectively and shorten the timeline. MD&A’s three (3) major divisions; MD&A Services, MD&A Repairs, and MD&A Parts supported this project.

For example, critical internal parts for the four (4) steam turbine main and reheat valves were machined at MD&A’s Valve Machining Shop.  These parts were then fitted and assembled in MD&A’s Valve Repair Shop (Figure 1). The actuators for these valves were repaired, rebuilt, and tested at MD&A Bearings, Seals & Hydraulics Repair facility (Figure 2). The new control system was developed and installed by MD&A’s Control Systems. MD&A also drew upon their internal expertise and deployed MD&A turbine specialty engineers and technicians to the site in support of such activities as technical direction, supervision, turbine alignment, valve casing repair, valve re-assembly, turbine seal fitment, controls, turbine commissioning, and startup (Figures 3 and 4).

Figure 1. Replacement Reheat Stop Valve Shown Alongside Existing Stop Valves

Figure 2. Refurbished Actuator

Figure 3. MD&A Performing Steam Turbine Installation at Site

Figure 4. MD&A Performing Steam Turbine Installation at Site

Lastly, MD&A’s developed a staggered “Just-In-Time” plan that integrated delivery of the components with the sequence of the replacement turbine buildout. This approach coordinated and optimized the manufacturing, delivery, and site installation activities to further shorten the critical path schedule.  For example, the Intermediate/Low-Pressure Rotor Assembly arrived at the airport in the early morning (Figure 5) and later that same day, it was installed in the lower half of the turbine shell at the plant (Figure 6).

Figure 5. IP/LP Rotor Assembly Package Unloaded at Airport

Figure 6. IP/LP Rotor Assembly Installed at the Power Plant

The RESULT:  MD&A completed installation 3 weeks earlier than the committed date. The total time from project start to turbine operation was less than 12 months. In addition to the key elements discussed above, critical to this success was MD&A’s responsive approach combined with extraordinary teamwork.  The Owner and MD&A approached this project as a team.  The Owner’s Plant personnel provided support in a variety of ways from the start of the project through turbine commissioning and startup.

A truly extraordinary accomplishment was achieved in the power industry with this Rapid Steam Turbine Replacement Project, resulting in a critical electrical generating unit returned to service for the Owner and their customers in less than half of the normal time.

In our 35 years, MD&A’s commitment to excellence has earned customer trust for all turbine-generator needs. We focus on delivering consistent quality and value with fast response, superior communications, and innovative solutions.

MD&A is easy to work with. We provide immediate access to expert help when you need it, where you need it. Around the corner or the globe, we ensure prompt, thorough communication and follow-through. For every repair job, large or small, the speed and effectiveness of our response team are matched only by the depth and breadth of our engineering expertise.

Find out today why so many power generators use MD&A to maximize operational effectiveness. Call us today +1 (518) 399-3616 or Contact us.