Session: CS-10-02 Recent Developments in Chinese Codes and Standards-2

Paper Number: 154492

154492 - Discussion on Allowable Hydrogen Leakage Rates of High-Pressure Hydrogen Storage Cylinders in Gb and Iso Standards 

Abstract: 

Both the ISO and Chinese GB standards specify an allowable hydrogen leakage rate of 6 ml/L/h for high-pressure hydrogen storage cylinders. However, the ISO standard permits cylinders up to 1000 L, while the GB standard allows a maximum of 450 L and does not limit the number of cylinders. This discrepancy means that under identical spatial conditions, the permissible hydrogen leakage rates are 6000 ml/h according to the ISO standard and 2700 ml/h per the GB standard, leading to a contradiction.

In this paper, we analyze the average hydrogen concentration in various spaces after trace hydrogen leakage reaches a steady state, considering different spatial and ventilation conditions. We calculate and provide allowable hydrogen leakage rates for typical space sizes and ventilation scenarios. By determining permissible leakage rates under more stringent spatial and ventilation conditions, we propose these rates as the allowable hydrogen leakage rates in product standards. Additionally, we clarify the constraints of space volume and ventilation conditions. When actual spaces and ventilation are more restrictive than the specified conditions, we offer a conversion formula for stricter allowable hydrogen leakage rates.

Our findings clarify that the allowable hydrogen leakage rate for cylinders should not be based solely on the leakage rate per unit volume of the cylinder. Instead, it must consider the actual installation space size and ventilation conditions as critical constraints. This study presents a more reasonable hydrogen leakage rate index for high-pressure hydrogen storage cylinders and provides a calculation method to assist cylinder users in determining allowable hydrogen leakage rates under varying conditions.

Presenting Author: Zhaoting Chen Zhejiang University

Presenting Author Biography: A doctoral student from Zhejiang University. Focus on the study of hydrogen leakage and diffusion patterns, as well as the development of the hydrogen energy industry.

Authors:

Zhaoting Chen Zhejiang University
Zhuoyu Chen Zhejiang University
Fang Han Zhejiang Guwei Technology Co.,Ltd
Quan Cao Zhejiang University
Jianfeng Shi Zhejiang University