Dibamba Power Development Company is a heavy fuel oil power plant, the first independent power producer in Cameroon. Operating in the power generation sector in Cameroon and part of the Globeleq Group, the company’s vision is to participate in Africa’s growth through the development and operation of power plants.

The Yassa-Dibamba heavy fuel oil power plant requires compressed air at two pressure levels: 30 bar for the engine start-up air compressors and 7 bar for the auxiliary instrumentation. To produce the instrumentation air, the plant has 3 air compressors running more than 5 000 hours per year with very short stand-by times.

In order to optimize its costs and to guarantee the contractual availability of its machines, the company thought of applying proactive solutions to allow them to anticipate the different failures of their machines and better plan the necessary contingency actions.

Using their new SDT340 ultrasound detector and its flexible sensor, they began to search for air leaks to improve their efficiency, as one of the compressors is currently out of service.

This research led them to identify several air leakage sources, some of which could be directly corrected, while others required further action.

To date, the effects are convincing. In spite of the actions that are still in latency, maintenance technicians are already able to observe instantaneous effects, namely the reduction of the number of hours of operation of these remaining compressors up to 30%. This translates into a reduction of more than 4 hours per day, per compressor, over the last two weeks. And this despite the absence of one of the compressors. The impact will be quantifiable with the costs related to energy consumption and maintenance based on operating hours and therefore annual material consumption.

The compressed air leakage searches allowed them to reduce the stress on their start-up air compressors and therefore the costs related to their operation, to name but a few. The LEAKReporter application has been a plus in helping management understand the impact of these inspections from a financial point of view with very easy to visualize analyses.

Studies are underway to define the periodicity for regular inspection rounds to maintain or even improve these conditions.

Compressed air leaks and screw pumps inspection in a Cameroonian power plant

The heavy fuel oil, to speak only of it, requires a rather complex treatment process that solicits several units, the majority of which have screw pumps that, before 2019, were the main sources of maintenance of the company, with an average of 200 million CFA (Central African franc) francs spent per year. This does not include downtime due to failures and even overtime generated during on-call maintenance teams.

The reliability of the installations depends on the state of the important number of auxiliary systems (pumps, centrifugal separators, compressors and others) contributing to the production of the 8 groups that the power station counts, each of which can produce 11MW (installed power).

In the case of these screw pumps, they have set up inspection routines which, coupled with the establishment of reference values, have enabled them to monitor failure states in order to recommend corrective/proactive actions in time. This has enabled them to considerably reduce their maintenance costs by up to 80% on screw pumps.