Net zero and the energy system transition
Net Zero Safety & Ignition Risk
National Gas are investigating the use of the National Transmission System to transport hydrogen and hydrogen blends. To support this research and testing is required to understand the risks of high pressure hydrogen transmission including ignition. This project will identify for 100% hydrogen and blends of hydrogen up to 20% the sources of ignition including how the distance of ignition sources affects the likelihood of ignition. It will also investigate the frequency and the different types of ignition events e.g. jet fires. Lastly it will look at the probability of ignition on sites and in pipework.
Hydrogen Impact on NTS Welds
Laboratory and full-scale testing have demonstrated that hydrogen gas affects the fracture performance of pipeline steel welds. To avoid severe knockdown factors stipulated by existing hydrogen pipeline codes mechanical property data from welds tested in high-pressure gaseous hydrogen is required to enable optimised operation of the NTS in hydrogen.
National Gas Transmission have conducted a series of fracture toughness and fatigue crack growth rate tests on a wide selection of pipeline steels and welds representative of those used on the National Transmission System (NTS). A thorough review of the welds tested and how these compare to the wider population of welds in service on the NTS is required to provide further confidence to use this data in pipeline repurposing assessments and for new build design.
Air Ingress in Multi Occupancy Buildings (MOBs)
This project will help to inform UK Gas Distribution Network Operators (GDNOs) and wider industry on the impact of the potential for air ingress into gas-conveying pipework in MOBs. The mechanisms for air ingress into gas-conveying pipework have been shown to be gas agnostic though this project will focus on impacts specific to future hydrogen distribution to MOBs.
High Pressure Venting and Flaring Demonstration for Net-Zero Gases Transportation
National Gas Transmission (NGT) own and operate the UK’s National Transmission System (NTS) transporting natural gas from terminals to end users. NGT have ambitions to repurpose the existing to transport hydrogen and hydrogen blends. Understanding the impact of hydrogen on our existing assets is a key enabler for this.
This project will conduct design of flare for hydrogen and its blends and vent system for hydrogen its blends and carbon dioxide and offline physical testing to provide evidence that hydrogen / hydrogen blends could be flared and vented safely and environmentally in for NTS.
Equations of State for Net Zero Gases
In metering applications Equations of State (EoS) are mathematical models that are used to convert measured volumes to standard units. This enables transfer from volume to mass allowing customers to be billed and for the networked to be balanced in energy. Metering and network balancing cannot be performed in volume as it doesn’t account for relative varying gas component concentrations – and therefore CV.
The EoS currently used (AGA8) is acceptable for up to 5% hydrogen but after this point it’s uncertainty is unknown – meaning the network may be unable to maintain accurate billing or system balancing. This project will obtain experimental data for a range of net zero gases and compare the output of several EoS for accuracy against real measured NTS-representative conditions.
Excess Flow Valve (EFV) Durability
This project will help to inform UK Gas Distribution Network Operators (GDNOs) and wider industry on the long-term suitability of existing Excess Flow Valve (EFV) designs in a future where hydrogen is being distributed in network pipelines. A risk to normal EFV functionality exists in the event that an ignition occurs within the downstream gas installation pipework and this project will help to understand the effectiveness of existing EFV designs to manage this risk identifying any necessary modifications to existing EFV designs where appropriate.