It is important to understand the design of the infrastructure required to allow blending into the NTS. There are multiple scenarios where hydrogen may be blended into the NTS which need to be considered:
1. High flow industrial blue hydrogen injection
2. Medium flow injection, such as from a large electrolyser site
3. Low flow injection, such as from a wind farm
Each of these connection scenarios should be considered as direct green field feeder connections, along with injecting at existing NTS sites.
The effect that the different flow rates have on the design of the infrastructure should be considered, along with the location of injection.
The findings of the project should also be applied to a specific test case: the design of a temporary hydrogen connection acting as a pilot for hydrogen blending into the NTS.
Benefits
Increase understanding of the connections process for hydrogen blending
Understand the behaviour of hydrogen when blending at NTS pressures
Determine the need for pre-blending or otherwise
Understanding of infrastructure, engineering design and costs of blended hydrogen connections of different types
Learnings
Outcomes
Phase 1 of this project has completed which provided a comprehensive Literature Review on the various infrastructure elements that would be required for various blending scenarios such as direct and indirect blending options. Various equipment was identified as possible solutions including tee blenders, various meters, injection probes, etc. Based on this output CFD (Computational Fluid Dynamics) modelling scenarios for Work Package 2 were devised and agreed. Currently, CFD analysis is under way to understand flow characteristics and composition mixing elements to add to a basis of design for future blending connection points. The outputs of this study will provide the direction for basis of design for what the blending infrastructure system would be and need to consider.
Work Package 3 will follow where the objective is to document and define the requirements, outline design principals, key design parameters and principal design standards for a minimum connection facility for hydrogen blending on to the National Transmission System. The basis of design is based on the work completed so far within Work Package 1.
As this is an innovation project the basis of design should not constrain the project by stating too many specific requirements it should instead provide a broad framework of the connection requirements. The subsequent conceptual designs developed will comply with this basis of design and potentially refine it as the design process develops.
Lessons Learnt
This project is still on-going but some initial lessons learnt gained from this project are listed below which are directly related to the change controls required for the project.
- This project encompasses many elements including aligning it to National Gas Transmissions first blending demonstration on the NTS. This has resulted in many challenges to overcome due to the innovation nature of the project. The lesson learnt would be to do a smaller discovery type project to prepare a more detailed design and enable the correct suppliers to be onboarded and involved at the correct stages. We have just sanctioned this to occur with a 6-month planning stage to enable a Re-opener request to be made to conduct a demonstration level test outside the scope of this project. This project was able to complete the detailed design studies as required but more refinement is needed on a larger scale which has been taken outside the scope.
- Enabling a longer duration in the project timeline to manage feedback and SME input during and at the end of work packages. It is critical that the correct stakeholders are involved in all of our projects. Due to the nature of this project impacting a significant number of teams around the business, it has made it difficult to get the resource time and capacity to support the demonstration.
