A novel adsorption cycle in which enhanced heat transfer between the adsorbent and external heat sinks and sources is achieved by forced convection of refrigerant gas through the adsorbent bed is presented This cycle is further developed by the use of inert beds to store the heat of desorption and sensible heat between phases. The performance and utility of such a cycle will depend on the heat transfer coefficients and pressure drops that result when the refrigerant gas is circulated through the beds The heat transfer and pressure drop characteristics of a bed of granular active carbon were investigated using argon, carbon dioxide and ammonia. Equipment was designed and built to pass a stream of gas through a bed at a controlled rate, pressure and temperature. The pressure drop characteristic was found to conform to Ergun equation and the constants for the application of that relation to a commonly available granular active carbon established. A mathematical model based on a finite difference technique was created and used to predict the progress of a temperature front in the bed and derive the heat transfer characteristics from experimental data. Heat transfer coefficients measured with argon and ammonia appeared inconsistent with each other and after investigations of the data and comparison with established correlations were made it was concluded that carbon during the argon experiments had been contaminated. The heat transfer results with ammonia and carbon were compared with a modified version of the Colburn analogy between heat transfer and pressure loss. A correlation between the Nusselt number and Reynolds number for design purposes was established.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:533009 |
| Date | January 1996 |
| Creators | Thorpe, Roger |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/34618/ |
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