This confidential client had tested and successfully developed SOFC (solid oxide fuel cells). They had tested them at a 1kW stack in a standard laboratory. They were using mass flow controllers to control the fuel (natural gas, air, and steam) which allowed them to have successful power generation. The key to this process was that the 3 streams of fuel had to combine in exactly correct ratios.
When the client decided to scale up the process, they built a 10kW stack for a 10 fold scale up. They transferred from mass flow to balanced plant characterized seat ball valves. After installing a system with manual controls for flow rate adjustment, the client was unable to get a steady temperature control or any current from the fuel cells.
I went to look at the system and brought in a subcontractor from our extensive network of industry experts. We spent a day analyzing and investigating the process and were able to determine that with the varying pressure flows, there was a varying pressure drop that led to non-linear control for the flow valves.
Our solution had several points that ultimately allowed the client to achieve the exact ratios needed for successful power generation. We also added other functions for further research and process improvement:
- Specified industrial mass flowmeters for air, fuel, and steam
- Reprogrammed the PLC to provide individual PID flow loops for each stream
- Programmed ratio tracking
- Installed a GE Intellution HMI/SCADA system to provide historical trends and alarming, to view system status, and to allow remote viewing of fuel cell tests in progress during nights and weekends
SPEC’s broad industry experience combined with our knowledge of advanced process technologies allowed us to identify and resolve the client’s flow control problem, delivering the ten-fold scale-up their business demanded.
Mr. Abboud, a Chemical Engineer, has been with SPEC since 2000, serving as Project Engineer and Sr. Project Engineer. Matt's diverse background as an Information Systems Manager, Process Engineer, Automation & Controls Engineer, and a System Startup & Support Engineer makes him a valuable asset from conceptual design to plant startup. Matt's DCS Automation platform experience includes DeltaV, Siemens PCS7, and ABB 800xA, His PLC Automation experience includes Rockwell Automation Platform (RSLogix 5, 500, 5000), Modicon Concept, Siemens Step7, and Opto22. His HMI experience includes Wonderware, Intellution (Fix32, iFix), and RsView.