Experimental studies have been made of counter-current water to water heat transfer in the nonsteady state. A paraflow plate heat exchanger was used and the non-steady conditions were produced by changes in the inlet temperature of the hotter of the two water streams. The design and construction of the apparatus is described. It was found that a diffusion mechanism had a significant effect upon non-steady heat transfer. Previous theories in this field were reviewed and extended to allow for this effect. The analysis of the results utilised a Laplace transformation with respect to the time variable and the calculations were carried out with the aid of the University of London's MERCURY digital computer. The diffusion coefficients were calculated to be between 1,000 and 5,500 BTU/hr. per °F./ft. for water flow rates of between 200 and 400 g.p.h. These results suggest that the diffusion effect is caused by a longitudinal mixing mechanism.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:602174 |
| Date | January 1962 |
| Creators | Cox, John Idris |
| Contributors | Newitt, D.M. ; Smith, W. |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/13684 |
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