A method for measuring cooling rates and boiling curves of thin plates during quenching in liquid is proposed. The method is demonstrated by using tinplates of thickness less than 1 mm. A specimen is composed of a couple of tinplates held together with a thin layer of ceramic adhesive, in which a thermocouple is located. One- and two-dimensional heat-transfer analyses in the specimen during quenching are carried out. The results indicate that the temperature difference in the specimen is so large that the temperature and heat flux on the surface should be estimated from the measured temperature value even if the specimen thickness is less than 1 mm, since the thermal disturbance induced by the thermocouple does not affect the temperature distribution over the specimen surface. In measurements of cooling rates and boiling curves, the specimen after heating to about 600 K is quenched in pure water in a range of subcooling from 10 to 50 K. It is found that the critical heat flux increases and the superheat at the point becomes higher with an increase of subcooling while the boiling curve in the nucleate boiling region is practically independent of subcooling, as indicated by previous works conducted with large specimens.
|Number of pages||13|
|Journal||Heat Transfer - Japanese Research|
|Publication status||Published - Dec 1 1993|
All Science Journal Classification (ASJC) codes
- Fluid Flow and Transfer Processes