MOBs Phase 3: Task 3 - Network Pipeline Capacity

There is a requirement for gas distribution network (GDN) operators to understand the cost, safety, and practicality of converting network pipelines from supplying Natural Gas to Hydrogen in multi-occupancy buildings (MOBs). Previous work undertaken during project ‘MOBs Work Pack 2 Asset Information Review’ identified the following gap in technical evidence relating to network pipeline capacity:
♦ The adequacy of the diameter of existing risers and laterals to supply the energy required with Hydrogen need to be investigated.
♦ The effects of an increased flow rate, velocity, or increased pressure (pipe integrity), should it be required to meet the demand without increasing the diameter of risers and laterals. This would need to consider the effect of altitude on Hydrogen riser systems, the pressure drops from existing fittings and additional safety devices installed (e.g. excess flow valves) and the minimum pressure required to ensure safe operation of Hydrogen appliances.
SGN is leading a feasibility project with some applied testing to understand the steps needed to convert MOBs to Hydrogen. The program is formed through 4 main work packs broken down into 2 main stage gated programmes (Part A = WP1, 2 & Part B = WP3, 4). This report is part of Work Pack 3 and summarises Task 3. The objective of Task 3 is to address evidence by examining the effects of increased volumetric flowrate, velocity and/or increased pressure (pipe integrity) using the OLGA (V2021.2) pipeline simulator.
An earlier report, described the survey of eighteen multi-occupancy buildings of various heights, ages and construction methods. Of the eighteen multi-occupancy buildings, eight were selected for analysis of capacity. A further two buildings representative of standard riser and lateral design were modelled with the data taken from the SGN management procedure SGN/PM/RL/1.
This report was submitted to HSE for their assessment of the safety evidence for 100% hydrogen heating, which can be found at Hydrogen heating: HSE assessment of the safety evidence - GOV.UK.
Queries should be directed to DESNZ: https://www.gov.uk/guidance/contact-desnz.