Back to PV-Hydrogen homepage.. TO HOMEPAGE

TECHNICAL ASSESSMENT

University of Strathclyde homepage
arrowOverview
Technical core
  PV Array
  Electrolyser
  Inverter
  Hydrogen
  Fuel Cell
  Matching
Building Integration
Economics
Environment
Risk Assessment
Conclusions
The Team
Links
References

 

LOG: week

 


HYDROGEN BURNING

At one point in the project the possibility of burning hydrogen to heat the dwelling was considered. As is outlined in the matching pages, it was found that 70% of the total energy demand comes from the thermal load (space and water heating). Rather than simply use electricity for heating (with expensive, highly rated fuel cells) it was decided to investigate the current technology "state of play" regarding the direct combustion of hydrogen.

Direct combustion

It was found that burning hydrogen in a conventional boiler was not only theoretically possible, but has been done many times and is a proven method of obtaining heat from hydrogen. Indeed, hydrogen was a major constitute of the "town gas" in use before cheap natural gas becomes available and as such there is a detailed knowledge base regarding its combustion.

The biggest problem with burning hydrogen is the combustion velocity (2.65 - 3.25 m/s for hydrogen compared to 0.40 m/s for methane). This means that it is difficult to control the flame, as high pressures are required. The jetting on the boiler must be modified and the hydrogen/air mixing closely regulated in order to produce safe and efficient combustion.

Catalytic hydrogen burning

A safer way of producing heat directly from hydrogen is by means of a catalytic burner. This method has several advantages over direct hydrogen combustion, notably that the combustion temperature can be closely matched to the desired temperature and that flameless combustion is invariably safer than flame combustion.

Catalytic burners consist of a porous palladium/platinum plate attached to the hydrogen source. The hydrogen enters the plate, diffuses in the pores and reacts catalytically to produce heat.

This method of heating using hydrogen has been used in several experimental installations (most notably in the Freiburg Solar House), and, again, is proven technology.

Conclusion

We concluded this brief investigation into hydrogen burning by deciding that, should we decide heating the dwelling using hydrogen produced from the electrolysers, a hydrogen boiler would be the most viable way. The investigation also showed us that the combustion of hydrogen was a major project in itself. As a result of these conclusions, it was decided to separate the thermal and electrical loads of the three test climates and concentrate only on the electrical loads.

Back to hydrogen index


Enquiries and comments to pvhydrogen@strath.ac.uk
Energy Systems Research Unit
University of Strathclyde
Glasgow