Assessing Safety and Performance of Natural Gas Distribution Systems When Introducing Green Hydrogen into the Fuel Mix

With the COP ending with a renewed focus on decarbonization, the transition to technologies that leverage hydrogen will be key in shaping this trend. Usage of existing gas transportation networks to transport hydrogen or hydrogen blended gas mixtures offers a pragmatic way to accelerate the transition to a lower carbon future. In this session, a typical existing natural gas distribution system that feeds industrial consumers e.g. boilers or gas turbines is considered for retrofitting. Introducing hydrogen into the fuel mix raises several safety issues, particularly around pressure/flow regulation and Wobbe Index compliance in the feed lines. We use first principle models applied in simulation tool packages offered by Siemens to simulate such a system. Through that, we will demonstrate safety related problems that may occur during operations like loss of supply or one of the consumer line shutting off. Such sudden changes in operational state result in disturbances that propagate through the system and can often lead to runaway scenarios that can severely jeopardize safety. Using the model, we will not only capture such scenarios but also use the model as basis to evaluate robust operating strategies that include for e.g. the addition of line packs, controlled dosing, placement of non-return valves, safely taking a line off for maintenance etc. Thus, comprehensively addressing foreseeable safety risks to the system through the model based digital twin. A brief overview on future work on deploying such models in operational / IIoT framework and application of AI based agents will also be provided.