Impact of High Speed Hydrogen Flow on System Integrity and Noise

Abstract Existing infrastructure used for transporting natural gas could be used in the future to transport hydrogen. The HyDelta program aims at resolving open questions connected to the transport of hydrogen in The Netherlands. Infrastructure is developed and operated safety by abiding by proven standards and norms for pipeline integrity. An open question is whether the integrity of the transport system is affected when repurposing for hydrogen, provided that the same amount of energy is as it currently is with natural gas. To ensure the same transport capacity, higher hydrogen flow velocities are necessary, in comparison to natural gas. This in turn results in potentially larger pressure drop, and with it a larger potential for erosion, vibrations and radiated noise. Transport capacity, operating pressures and temperatures, sizing of the hardware and optimized economic return determine what the optimal design flow speed in the system shall be. However, the flow speed is also limited by integrity risks. For natural gas, this limit is commonly placed at 20 m/s (∼60 ft/s). Applying the same limit to hydrogen may represent an overly conservative constraint and bottleneck the capacity of new and re-purposed gas transport systems. In this paper, a review of integrity risks related to high gas flow velocities in the system is offered: flow-induced risk mechanisms for intrusive equipment, flow-induced turbulence, flow-induced pulsations, acoustics-induced vibration, flow-induced noise and erosion. The method is based on benchmarking hydrogen against (Dutch) natural gas, at equal energy rates. This means that hydrogen should flow about 3 times faster than natural gas. The objective is to assess whether any of the integrity risks analyzed present a barrier to allowing the flow velocity for hydrogen to be larger than that used for natural gas.