A METHOD OF MEASUREMENT FOR THE FLAMMABLE LIMITS OF HYDROGEN |
|---|
| Young-Do Jo, Jin-Jun Kim |
- Abstract:
- The current method for determining the flammable limits for a gas in a closed spherical vessel is based on a specification of the maximum pressure increase during the combustion, usually from 5 to 10% of the initial ambient pressure. This approach is completely arbitrary and is not fundamentally based. For most hydrocarbons this pressure boundary and hence the flammable limit is easy to determine experimentally since an abrupt pressure drop occurs at the flammable limit as the fuel concentration in air is adjusted. However, for some species, particularly hydrogen mixed with air, the drop in maximum combustion pressure is not very abrupt and the fuel concentration can range several percentage points depending on the arbitrary criterion used for the flammable limit.
This paper will discuss a new approach for determining the flammable limits for a gas in a spherical vessel. The approach is based on the maximum second derivative of pressure rise. The second derivative is indicative of an acceleration of the combustion rate and is, hence, fundamentally based. Furthermore, we have identified a new approach to determine the downward propagating flammable limits based on the combustion time, that is, the time that the gas actually burns in the vessel. - Keywords:
- flammability, upward flammable limit, downward flammable limit, hydrogen
- Download:
- IMEKO-WC-2012-TC20-P1.pdf
- DOI:
- -
- Event details
- Event name:
- XX IMEKO World Congress
- Title:
Metrology for Green Growth
- Place:
- Busan, REPUBLIC of KOREA
- Time:
- 09 September 2012 - 12 September 2012