Prevent restart problems after planned maintenance

Prevent unplanned shutdowns when restarting power plants after planned maintenance

Planned maintenance is essential for the long-term reliable operation of power plants. A maintenance outage begins with the shutdown of the power plant and the isolation of key systems, such as fuel and lubricants. Following the disassembly, inspection, and reassembly of turbine components, the isolated systems are restored and the power plant is started up again. It is important to ensure that task management, system isolation and restoration management are properly carried out to prevent problems during restart.

Avoid errors and omissions during planned maintenance

Planned maintenance of power plants today relies upon human labor, and errors and omissions can occur. For example, the isolation and restoration of manual valves to operating positions are often tracked manually on paper, giving rise to the risk of omissions. In addition, fuel branch pipes for gas turbines have 200 to 400 connections with flanges, and some of them have the same shape placed adjacent to each other, raising the risk of incorrect installation. Furthermore, when it comes to controlling the carrying in and out of tools in areas that require control for foreign objects, such as turbine disassembly areas, checks are carried out manually on paper, which takes time and increases the risk of mistaken or omitted entries of records. Errors and omissions caused by relying solely upon human labor can lead to unplanned shutdowns and serious damage to turbine components when power plants are restarted. Improved and more efficient operational procedures are paramount to prevent such errors and omissions occurring.

PTW Management prevents omissions in systems isolation and restoration

Planned maintenance of power plants involves hundreds of tasks carried out in parallel, on both the turbines and auxiliary equipment. The isolation of key systems and their error-free restoration prior to power plant restarts are important to prevent problems during restart. The greater the number of operations, valves, and power sources to be controlled, the more difficult control can become, increasing the risk of human error during the isolation and restoration processes. Many of these operations today are controlled manually and on paper, resulting in multiple time- and labor-consuming spin-off tasks, such as the creation of documents, searching for valves, and the sharing of progress updates with related parties, as well as greater risk of errors and omissions.

PTW (Permit To Work) Management, an app that visualizes and shares work plans and progress, helps avoid these risks. PTW Management incorporates system diagrams and power source information into a controlling computer, enabling maintenance teams to plan the isolation and restoration of systems and power sources, and follow progress, checking which tasks have been completed and which have not yet been started. The app also provides guidance on the locations of manual valves and gives instructions on the opening position of each manual valve. The time required to locate manual valves has been reduced by up to 50%. Operators can work quickly and with certainty as they check the isolation and restoration list on mobile devices. The valve open/closed status registered on-site with the app is sent to the controlling computer, enabling outage managers and maintenance teams to coordinate their information. The system is equipped with high-speed processing technology, making it possible to handle higher data volumes. Through its use of Mitsubishi Power designed piping system diagrams, PTW Management makes it possible to systematize the information efficiently.

PTW Management helps prevent isolation and restoration mistakes.

GT Fuel Piping Installation Guidance prevents mistakes in the installation of fuel branch pipes for gas turbines

There can be as many as 100 to 200 fuel branch pipes connected to gas turbines, and the number of connection points ranges from 200 to 400 because they need to be connected on both the manifold side and the combustor side. Some of the flanges have the same shape, and are easily confused when connecting adjacent pipes. This can result in unplanned shutdowns during gas turbine restarts. Measures to prevent mistakes are urgently required, as the large number of pipes makes it time-consuming to identify the causes of shutdowns, resulting in lost opportunities for power generation.

These risks can be avoided with GT Fuel Piping Installation Guidance, which uses 3D CAD data to visualize in three dimensions where fuel branch pipes have been installed. A QR code can be read and recorded to check whether the pipes have been correctly installed (QC check), allowing the outage manager to confirm that the piping connections are correct as the work is being carried out.

GT Fuel Piping Installation Guidance helps prevent fuel branch pipe connection mistakes.

AI FME Management prevents tools being left behind in areas controlled for foreign objects

During planned maintenance of power plants and other facilities, workers enter and work inside turbine enclosures and casings. To avert the risk of equipment damage that can occur due to the presence of foreign objects inside turbines during restart, relevant work areas must be designated as areas controlled for foreign objects. Today, as workers enter and exit such controlled areas, the entry and exit of each worker’s tools is manually documented on paper. However, errors and omissions have occurred in the past, and the time required for checks has also been an issue.

AI FME (Foreign Material Exclusion) Management helps to resolve these issues by using AI and image processing technology to control and check the entry and exit of tools in controlled areas. It records images of the tools as they are brought in and reliably documents any tools inside the foreign object control area with digital images. When a tool is taken out of a controlled area, image recognition is used to verify that it is the same tool that went in, enabling highly accurate control of tool entry and exit. Even diverse and specialized tools can be identified with high accuracy by a system that combines AI technology, image processing technology and matching operations. AI FME Management helps to prevent unplanned shutdowns and equipment damage resulting from tools being left behind in controlled areas. By enabling quick and highly accurate checks, it can also reduce the labor costs of checkers.

AI FME Management helps prevent foreign material incidents.

Digital support made possible by TOMONI®

The above apps that support the planned maintenance of power plants belong to the TOMONI suite of intelligent solutions. With its suite of digital solutions using sophisticated control functions, AI and our expertise in power plant design, operation, maintenance and various systems, TOMONI supports smarter energy systems for our customers.

• Prevents errors and omissions during planned maintenance
• Reduces manual workload and improves quality of maintenance
• Avoids trips and equipment damage during restarts