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Projects: Projects for Investigator
Reference Number	NIA_NGGT0188
Title	Variable Hydrogen Blend Compression
Status	Completed
Energy Categories	Fossil Fuels: Oil Gas and Coal(Oil and Gas, Refining, transport and storage of oil and gas) 50%; Hydrogen and Fuel Cells(Hydrogen, Hydrogen transport and distribution) 50%;
Research Types	Applied Research and Development 100%
Science and Technology Fields	ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 100%
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Project Contact No email address given National Grid Gas Transmission
Award Type	Network Innovation Allowance
Funding Source	Ofgem
Start Date	01 March 2022
End Date	01 September 2022
Duration	ENA months
Total Grant Value	£140,000
Industrial Sectors	Energy
Region	London
Programme	Network Innovation Allowance
Investigators	Principal Investigator	Project Contact , National Grid Gas Transmission (100.000%)
Web Site	https://smarter.energynetworks.org/projects/NIA_NGGT0188
Objectives	The project will develop a model of a typical compressor on the NTS which will then be used to study the effects of hydrogen blends of 2%, 20%, 50%, 80% and 100% hydrogen and limitations of future hydrogen service. Options for retrofitting the typical compressor will be investigated and the model adapted for a selection of the most viable options to determine their effect on compressor operation with hydrogen. The most promising retrofit option for each hydrogen blend will then be used to assess variability and explore the limits of varying hydrogen concentration above and below the specified blends. Potential sensing systems will be investigated which could detect hydrogen concentration and communicate hydrogen concentration in real time to enable the compressor to operate as required. A technical review of alternative compressor technologies will be undertaken, and the technologies will be compared with potential retrofit options. Measurement Quality StatementThe measurement approach used to meet Data Quality objectives will be through the identification of high calibre project partners who are experts in their given field. In this instance the project will be limited to a desktop study and analysis from TRL2 to TRL3 to inform new insights into the use of existing NTS compression assets with variable blends of hydrogen. Data Quality StatementThe project will ensure that data used is of sufficient quality to deliver project objectives by selecting a typical compressor where there is sufficient operational and original design data to ensure a robust analysis can be undertaken. The relevant data and background information will be stored for future access within the National Grid Innovation SharePoint site. The project will be split into 3 Phased work packages:1) Work Package 1 – Model Development (Duration – 9 weeks)Lead – Frazer-Nash Consultancy and National Grid Work Package 1 will include: Model existing compressor fleet: identify one compressor which is typical, where suitable operational and OEM design data is available, and derive compressor map. Create analytical model of a single stage compressor based on geometry and operational parameters of identified compressor. Model inclusive of hydrogen service: Assuming constant shaft speed and volumetric flow, understand the effect on stage loading and efficiency for a range of blends of hydrogen (2%, 20%, 50%, 80% and 100%). Model greater flow rate: Repeat model of stated hydrogen blends with a range of flow rates and identify upper limits on flow rate. Operational envelope: Derive limitations of future operation due to capacity and performance and understand the limitations from associated plant, including motor unit or gas turbine. Comment on wider network effects and how change in pipeline frictional losses may mitigate operational constraints. Estimate the effect on asset life. Compressor Efficiency: Estimate additional losses (e.g. inlet volute, exhaust, etc.) and multistage compressor efficiency considering different configurations (series and parallel) of compressors. Production of revised compressor map(s). 2) Work Package 2 - Investigation of retrofitting options and review of alternative compressor technologies (Duration – 4 weeks) Lead – Frazer-Nash ConsultancyWork Package 2 will include: Retrofitting of existing centrifugal compressors: explore retrofitting options across a variety of industries and select the most viable options for further investigation. Options to be review will include, but not be limited to, shaft speed increase, inlet guide vanes and inlet diffuser vanes. For each option identified, the compressor model will be adapted to represent the modification and the effects on operational limits explored. Variability of hydrogen concentration assessment: the most promising retrofit option for each hydrogen blend (2%, 20%, 50%, 80% and 100%) will be selected and the limits of varying the hydrogen concentration above and below the specified concentration will be explored. New performance maps for feasible concentration ranges will be derived. Potential sensing systems, which would enable the compressor to operate dependent on the hydrogen concentration of the process gas, will be investigated. Technical review of alternative compressor technologies: Identify current and novel compression technologies and create a weighted decision matrix to score each technology against key criteria such as efficiency, operational ranges, ability to handle variability in hydrogen blends and component lifespan. Extend the weighted decision matrix to include retrofitting options to provide a high-level comparison of all options investigated. 3) Work Package 3 - Cost Estimation and Reporting (Duration – 3 weeks) Lead – Frazer-Nash Consultancy and National GridWork Package 3 will include: Cost estimation: A rough order of magnitude estimate of costs for reworking existing compressors to support different blends of hydrogen including an estimation of CAPEX, OPEX and expected asset lifetime versus the typical compressor. Recommendation on appropriate investment decisions based on each single hydrogen blend scenario. Recommendations on appropriate investment decisions based on the variability of hydrogen concentration assessments considering the lifetime and cost of replacement components based on operation with the ranges of hydrogen concentrations analysed in Work Package 2. Reporting: final project report detailing all work carried out, conclusions and recommendations to inform NTS compression strategy.  The main objective of this study is to support decision making on whether the NTS compression fleet is compatible with blends of hydrogen from 1 – 100% and assess whether variable blends can be tolerated. Display quantitative changes in operating envelope and required shaft power of compressor with 2%, 20%, 50%, 80% and 100% hydrogen. Understand changes of operating envelope and available power with current operational conditions. Understand the implications of a variable hydrogen concentration on compressor operating envelope and efficiency. Understand impact of hydrogen blends on lifetime of compressor and components. Understand change to maintenance regime required to accommodate hydrogen. Understand the suitability of alternative compressor technologies for compression of pure hydrogen and hydrogen blends.Understand cost of replacement and retrofitting compared with current compressor fleet.
Abstract	During the energy transition, it is likely that consumers will have differing gas composition requirements, and the National Transmission System (NTS) will have to transport varying percentages of natural gas and hydrogen within the gas blend. This creates a challenge for compression as centrifugal compressors will have to operate at variable speeds to compress varying gas blends. Automated systems at compressor stations will be required, which can sense the gas composition at the inlet of the compressor and feedback to control compressor operation. This desktop-based study will investigate the effects of varying hydrogen blend on the operational parameters of a compressor and research potential modifications to existing compressors, alternative compression technologies and sensing systems which could enable compression of variable gas blends on the NTS.
Publications	(none)
Final Report	(none)
Added to Database	14/10/22