Analysis of Advanced Flight Vehicle Heat Exchanger Fire and Explosion Hazards
Abstract
The use of highly compact and lightweight hydrogen heat exchangers envisaged for advanced flight vehicles has introduced problems associated with flight safety. A hydrogen leak permitting the hydrogen gas to mix with high temperature ram air can result in autoignition of the gas-air mixture with subsequent failure of the entire heat exchanger. In this work, heat exchangers were simulated by placing one or more hydrogen bearing tubes in a heated air stream. The leaks were simulated with various diameter holes (.0235-.040-inch) drilled through one wall of the tubes. Air mass velocity through the test section was varied from 1 to 38 lbs/sq ft sec. and the temperature of the heated air was varied to obtain the minimum air temperature to effect ignition of the gas-air mixtures. Ignitions were obtained with tube holes as small as 0.0135- inch diameter and hydrogen leak rates up to 0.56 SCFM. The ignition temperature fell between 1000 and 1300 deg F and increased with increasing air flow rate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1965
- Accession Number
- AD0365826
Entities
People
- A. Bartkowiak
- A. L. Furno
- I. Spolan
- J. M. Kuchta