Analysis of compact heat exchanger performance
Abstract
Many cryogenic heat exchangers employ high-conductance metallic screens or perforated plates separated by insulating spacers normal to the fluid flow direction. Packed-bed regenerators employing wire screens, perforated plates, or granular particles also have a similar structure. The temperature profile along the length consists of many steps. The ineffectiveness due to axial conduction adds to that due to finite number of plates and finite heat transfer coefficient. A closed form expression is derived for the efficiency of a compact heat exchanger with given design N sub tu where the exchanger consists of layers of metallic screens, plates, or particle layers. It is observed that the effect of discrete temperature profile becomes significant when the per stage design N sub tu exceeds about 0.5.
- Publication:
-
Presented at the ASME Winter Ann. Meeting
- Pub Date:
- December 1984
- Bibcode:
- 1984asme.meet....9S
- Keywords:
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- Cryogenics;
- Fluid Flow;
- Heat Exchangers;
- Heat Transfer;
- Thermal Conductivity;
- Performance Tests;
- Regenerators;
- Temperature Control;
- Fluid Mechanics and Heat Transfer