Coal bed methane monitoring

Now a subsidiary of Arevon Energy, Harworth Power (‘HPL’) was established to utilise and manage the non-core resources of Coal mining operation in ways that are cost effective and innovative.

HPL’s main business activity is the conversion of mine methane gas into electricity, which generates income from electricity production and also reduces the volume of greenhouse gas emitted to atmosphere. 

HPL has a number of gas-to-energy sites around the North and Midlands regions.

After consultation with HPL, it appeared that the main issue with the process was that engines were frequently tripping or shutting down whenever fluctuations in gas quality or pressure were detected. The existing system provided only very basic alarm reporting and was proving unreliable and prone to locking-up. Whenever an alert was received, it required a site engineer to visit each time to restart the engine manually if it had stopped. This setup had resulted in many hours of lost revenue because engines remained off whenever site engineers were not able to visit or had not been alerted until the following day. 

Dexdyne’s proposed solution was firstly to install a netrix Industrial unit with each engine to monitor the state of the engine, gas quality/pressure and power generated (by using a separate power meter), whilst also providing digital outputs to control relays that allowed remote restarting of the engine via a HTML based mimic over the internet.

Alerts were configured to send SMS messages on various alarm levels to appropriate staff and to restrict the control aspect of the web application when either certain alarm conditions arose or when untrained personnel logged into the system. The second aspect of the solution was to improve the status and reporting functionality. 

Dexdyne supplied its newly developed netrix Dashboard system with a customized page showing the status of each engine, with real-time updates as the status of each engine changed.

When it came to reporting, the existing method of getting site information – such as total MWH’s generated – was to dial up each site in turn (using an old analogue modem), connect to the installed PC and make a note of these details. However, these remote systems were prone to crashing and the whole process of collecting data from multiple sites was very time consuming.

With netrix all this information is automatically collected and pushed hourly into an SQL database running on the netrix Server. From this information the netrix Server is programmed to send the totals for hours run and MWH’s generated for each engine, as well as engine availability, in Excel format as an email attachment to several people each day, week and month.

After the netrix units had been installed, additional facilities were added, such as a PDA version of the Dashboard for mobile engineers.

Three months after the initial site installation, HPL is now enjoying significantly better uptime on its engines, which has resulted in improved revenue.

A second project was started later in the year which required netrix to provide a complete monitoring solution for the gas extraction plant based at Stillingfleet. Here netrix used a direct Modbus communications link to the Hasse gas extraction system to provide a live telemetry feed. The system was also set up to send SMS alert messages to the site operations team when the process parameters strayed outside normal operational ranges.