Standards Development

Scope

The proposed documents will address the general design and development process for the definition and verification of fuelling protocols and the implementation of the protocols for dispensing fuel to hydrogen vehicles rated up to 70 MPa nominal working pressure (NWP).

A multipart set of documents is envisioned. This NWIP proposes the following 3 Parts:

1) Design and development process for fuelling protocols A standard design and development process are envisioned to ensure that work is conducted in an orderly and transparent manner to improve understanding and facilitate acceptance and implementation of the protocol in dispensing systems. Lessons learned during previous protocol development efforts will be considered to allow the process to be conducted expeditiously. The intent will be to accept protocols from various SDOs (ISO, SAE, …) and private sources as long as the documentation and verification of the protocol are consistent with requirements of this part. The validation of reduced-order models can be performed through a combination of applying experimentally validated detailed science-based modelling (such as HyTransfer) and/or experiment. The use of fast-running, validated, reduced-order science-based models will be encouraged to expedite the development and verification of the protocol over the full range of fuelling possibilities. This validated reduced-order model can also be considered for use in the dispenser control system. Although the primary motivation for this standard is related to high flow heavy duty applications, it is expected that the Scope covers all road and off-road applications including light duty (LD), medium duty (MD) and heavy duty (HD) high-flow (HF) (that would span from cars to rail and maritime applications).

Key steps in the process are described below:

• Definition of Requirements

Determination of the full extent of variations in fuelling conditions, vehicle storage system and operating characteristics, dispenser capabilities and limitations, and other constraints of the application will be emphasized as part of the definition of requirements to ensure that the full range of fuelling possibilities are addressed in risk analyses and verification activities.

• Concept Definition and Evaluation

The developer of the protocol will have flexibility to define the specific protocol to be developed and the type of communication between the vehicle and the dispenser control system based on the selected approach being acceptable from the perspective of technical and safety risk assessments.

• Development of the Fuelling Protocol

Verification of the protocol can be accomplished through a combination of analysis using validated, science-based detailed models and/or experiment, but, given the likely number of design cases that may need to be addressed, it is anticipated that numerous scenarios will need to be evaluated by validated, reduced-order models. Validation of these reduced-order models can be performed with detailed, science-based, experimentally validated detailed modelling and/or experiment.

• Documentation of the Fuelling Protocol

After completing verification of the fuelling protocol, methods to document and establish a basis for acceptance of the protocol will be defined. The goals are to facilitate use of protocols from various sources as long as the protocols are properly verified to be acceptable over the entire range of fuelling possibilities.

In addition to the description of the fuelling protocol, the developer of the protocol will define and document all parameters, constraints, and assumptions that were used to define and validate the protocol as well as guidance and requirements for implementation of the protocol in the dispenser control systems.

• Implementation of Fuelling Protocols in Dispenser Control Systems Developers of dispenser control systems need to convert the fuelling protocol into the dispenser control functions such as user interfaces and protective functions. Ultimately, the entire functionality of the dispenser control system needs to be validated as part of part of product qualification. 

2) Definition of communications between the vehicle and dispenser control systems This part will provide basic information needed by the developer of fuelling protocols to define the methodology and data to be transmitted between the vehicle and dispenser control system. Additionally, it will serve to determine basic requirements for communication based on the intended use of the data for data collection, process control (as part the fuelling protocol), and/or protective functions of the dispenser control system.

The Scope covers basic principles and minimum requirements for communication for the above applications.

Understanding these items is important to the developer of the fuelling protocol as these decisions significantly impact verification requirements for the protocol as well as the protocol itself. As noted above, it is anticipated that generally both static and dynamic parameters will be communicated between the vehicle and the dispenser control system. Static parameters could include, for example, container type, heat transfer parameters, NWP(s), temperature rating(s), container and compressed hydrogen storage system (CHSS) capacity, and information related to the ability of the CHSS to perform control and protective functions related to the fuelling process. Dynamic parameters include the pressure and temperatures of hydrogen gas within the container(s) and input for control strategies such as maximum hydrogen flow to be dispensed and discrete commands as “stop fuelling” and “abort fuelling” signals. Part 2 will identify possible variable types and a format for transmitting data that can be universally interpreted by various vehicles and dispenser control systems.

The intent of Part 2 is to provide the basic information and requirements needed to design and develop the communication between the vehicle and dispenser. Requirements for the integrity of communications will also be defined so that the developer of the fuelling protocol can implement hardware and software that is consistent with the intended use of the data within the dispenser control system.

3) High Flow Hydrogen Fuelling Protocols for Heavy Duty Road Vehicles A universal and versatile HF (above 60 g/s) hydrogen fuelling protocol for HD applications including buses and trucks with primary focus on H70 HD HF road vehicles and systems with large hydrogen capacity at gaseous hydrogen fuelling stations. The protocol will aim to be as versatile as possible by addressing HD 70 MPa NWP. Additional effort may include H35HF and H50HF concurrently but, not to impede the progress of a H70HF standard. The priority for publishing this standard will focus on H70HF fueling.

Approach:

• Develop science based and empirically validated fueling protocols which are coordinated with the appropriate HF nozzle, receptacle and communications for HD vehicles

• Adopt best practices for fueling taking into consideration regional experiences

• Coordinate with established and other relevant standards groups such as SAE

• Consider the results and findings of the European Commission funded project “Protocol for Heavy- Duty Hydrogen Refueling” (PRHYDE)

• This document can be viewed as a stand-alone document to address a high flow fueling protocol or it could be viewed as part of a series of documents that address the general definition and verification of fueling protocols and communication protocols

The aim is to use both, static and dynamic parameters. Static parameters could include: tank type, thermodynamic parameters (e.g. ability to sink heat), CHSS NWP, CHSS temperature ratings (e.g. inlet gas temperature, tank gas temperature), total tank capacity, interconnecting tubing, ability to control fill by the application (i.e. presence of on/off valves, control valves, etc.), presence of cascading tank systems, tank specifications and credentials (verification that CHSS is a certified/type approved system).

The protocol will also use dynamic parameters, which could include: starting pressure and temperature in the tank, current (real-time) pressure and temperature, mass flow, etc., as well as fueling commands, such as (but not limited to) stop/abort, etc.

It is widely regarded in industry that such a fueling protocol would offer considerable benefits over currently existing ones by offering energy savings, simpler systems, better fueling performance and a better functionality for the customer (e.g., it could be implemented to fuel up to a certain value of hydrogen or offer other advanced customer functions).

Although the scope is specific to high-throughput (> 60g/s flowrates) HD applications, this NWIP is envisioned to expand from work already conducted for the fueling infrastructure under WG 24 for ISO 19880-1.

While the focus will be on CHSS for HD applications (typically 30 kg – 100 kg capacity), this protocol could also be applicable to other end uses, such as the fueling of trains, ferries and other applications requiring a large amount of hydrogen. Also, the aim would be to allow the same protocol to be used at different station designs with varying degrees of storage capacity so it could include fueling system  specification options on the infrastructure side. 

Purpose

The early deployment of FCEVs and development of a fuelling protocol for light duty hydrogen-fuelled vehicles was launched with the coordination and support of governments and auto manufacturers from Europe, Asia and North America. Similarly, a global effort is needed to establish a relevant and practical fuelling protocol for heavy duty vehicles, especially in view of the multitude of regulations being passed on CO2 reduction around the world. With road transport being the only sector that did not achieve a CO2 emission reduction since 1990, it becomes increasingly important to focus on transportation and HD vehicles, in particular.

These CO2 reduction regulations around the world require a technical framework for fuelling that enables HD vehicle manufacturers to be successful and is the cornerstone of infrastructure deployment. It is currently the item that is holding back the introduction of hydrogen powered Heavy Duty vehicles into the market and bears significant possibilities for cost reduction.

In Europe, Directives that set out the legal requirements toward zero emissions infrastructure need to refer to EN standards or ISO standards if an EN standard has not yet been developed; hence this standard is aimed to be included in the European AFID for heavy duty transport. It is, therefore, critically important that this standard be coordinated at a global level with the support of member countries including USA, Germany, Canada, France, Netherlands, Denmark, Japan, Korea and China. It is widely regarded in industry that fuelling protocols developed to this standard will offer considerable benefits over currently existing ones by offering energy savings, more efficient systems, better fuelling performance and higher functionality and enhanced safety for the customer.

Timeline:

Develop a H70HF fueling protocol standard in 3 years. The different parts within this NWIP (Task Forces 1, 2, and 3) will have their own independent schedule and will be published according to their work being concluded.

Consider the following: Is there a verified market need for the proposal? What problem does this standard solve? What value will the document bring to end-users? See Annex C of the ISO/IEC Directives part 1 for more information.