Drones boiler inspection

The project

Our steam generator inspection and monitoring operations are moving more and more towards digitalization. For this reason, we have started using drone technology

Drones were conceived for use mainly in the military sphere or for recreational purposes. Over the last few years, however, they have started to play an important role in various fields, backing up work in various industries. They are used, for example, for aerial filming and photography, to check the surrounding environment but also even for home deliveries.

In order to improve the quality of people’s lives and the future of the Planet, we set ourselves the objective of pushing our activities to an increasingly technological and digital level, embracing innovation and starting from activities in confined spaces, where the risks for our workforce in the field are greatest. In particular, we have begun a project to trial the use of an indoor drone during the inspection of steam generators and underground passages in thermoelectric facilities. The trials took place in hydroelectric plants in Valtellina and Calabria and the thermoelectric power station of Sermide in Lombardia (https://www.a2a.eu/it/gruppo/nostri-impianti).

At the Sermide thermoelectric site in particular, an indoor drone was flown inside the heat recovery steam generator of the CCGT (combined cycle gas turbine). Drones allow operators to inspect the steam generator from the outside, reducing the risks related to confined spaces and thus improving safety. Moreover, the drones make it possible to carry out facility inspection, maintenance and monitoring activities with greater agility, rapidity and accuracy. In addition to guaranteeing the greater repeatability of yearly inspection procedures, they simplify comparison and the filing of data. The drones can, in fact, gather countless high-definition images for the identification and subsequent assessment of possible anomalies.

The advantages

A latest generation technology that makes work safer and reduces times and costs

The advantages of using drones are numerous, ranging from the greater protection they offer staff to the optimization of times and costs. Here, in more detail, are the main benefits:

Improvement in safety

The energy sector has many assets such as steam generators, stacks, transformers and other plant that require regular inspections.
By using drones in preliminary inspections, workers are less exposed to risks and site safety is enhanced. The possibility of carrying out legally required periodic checks non-invasively – without the need for internal inspections by plant officials or maintenance workers – is of vital importance. In this way, we can reduce worker exposure in confined areas and thus also reduce health, safety and environment (HSE) risks, as required by Italian law.

Possibility to carry out checks in inaccessible places

Considering the height at which inspection points are located, around 10 metres above ground for steam generators and 20 metres for stacks, inspection in both cases requires the installation of scaffolding, with workers in a confined space and at a considerable height. With drones, on the other hand, the heights, confined spaces and everything that is difficult or dangerous to reach become simple and safe.

Cost reduction

Drones have proved to be very advantageous from an economic point of view too, making it possible to reduce costs by not having to use scaffolding or other machinery, at least in the initial phase of inspections. The operations that we have developed, concerning the opening of inspection or access panels, the installation of scaffolding, preparation for pressing, machine support for forced ventilation, mean that we move on to more costly activities only where a breakage has been ascertained.

More efficient use of time

Utilizing this technology enables us to take action more quickly, minimizing further the number of days of production downtime.

Greater accuracy and quality of data

Drones also make it possible to perform more thorough and accurate monitoring (also with the use of topographic software), as well as offering the possibility of taking material samples by means of non-destructive testing (NDT) alongside visual inspection.

Our analyses

With drone technology, we save time and improve the quality of information

By analysing the main problems of the steam generator, we have seen that, in the generator’s exhaust and adduction flues, there can be erosion/corrosion and structural damage caused by the blast waves resulting from combustion. The same problems can also be found in stacks, where silencers are subject to acid corrosion by the exhaust fumes.
Beginning with analysis of the plant affected, where we have compared the use of drone technology with more traditional procedures, important findings emerged.

100%

of points that can be inspected with a suitable quality for visual checks; both details and brightness turned out to be better than expected.

More than 85%

of operations performed outside confined spaces: this percentage could increase further with the use of 3D models in support of the pilot and of self-guidance.

-60%

reduction in inspection times: ten working days of traditional inspection correspond to four days with the use of drones.

-88%

reduction in costs: costs of 45,000-50,000 euros with traditional inspection methods correspond to 4,000-7,000 euros with the use of drones.