Ensuring safety for H2 dispensing systems
Working with a manufacturer of forecourt dispensing systems to develop a certified hydrogen dispenser
Overview
A hydrogen filling station typically consists of multiple building blocks - the H2 source (pipeline, on-site electrolyzer, or compressed storage), a multi-stage compression system (for 350 or 700 bar dispense), hydrogen coolers (reduces the gas temperature to -40°C prior to filling the vehicle), and the part that the driver will see - the dispensing system. That dispenser typically contains the metering & control systems for the final stages of the dispensing process, as well as the information display for the driver.
Project Brief
Because of the relatively low risk of a hydrogen leak, the dispensing system was required to have Zone 2 protection. A purged and pressurized (Ex p) solution was seen as the simplest method to ensure safety and obtain the necessary product certification for the customer's target market. A solution was required that was fully automatic and would not require intervention, other than during planned inspections and maintenance.
Challenges
- Identify a suitable purge controller with a small footprint, requiring minimal intervention, and having the right certification for the various target markets.
- Ensure the system internals were suitable for purging in terms of component ventilation in line with standard 60079-2
Outcome
- Expo's engineers worked with the client and selected the SmartPurge II as the most suitable system - while suitable for Zone 1 areas, the SPII had the right physical characteristics and level of automation. It also has a wide range of flow rates, meaning that it can be used across physically different sized dispensing systems without needing to select a larger system.
- Expo's consultancy team worked with the client's Notified Body to deliver the required certification.
Expo Products and Services
- Expo SmartPurgeII
- Design services
- Certification consultancy