Evaluation of heat transfer coefficients for annular spaces

Author

Jacob Levine, New Jersey Institute of Technology

Document Type

Thesis

Date of Award

6-30-1960

Degree Name

Master of Science in Chemical Engineering - (M.S.)

Department

Chemical Engineering

First Advisor

Jerome J. Salamone

Second Advisor

George C. Keeffe

Third Advisor

C. L. Mantell

Abstract

The object of this thesis is to find the best approach for evaluating the heat transfer coefficients in annular spaces.

The system studied consisted of air in turbulent flow through steam heated annuli. Twelve pipe ratios were tested, with a pipe diameter ration range (D₂/D₁) of 7.0 to 1.3.

It WAS found, contrary to most literature, that at constant values of W/A μ, the heat transfer coefficient decreases as the standard equivalent diameter decreases (D_e=D₂-D₁). Because of this observation, the use of a Reynold’s number based on an equivalent diameter is inapplicable.

Applying the data of this thesis to Davis’ correlation4, good agreement is found except for the constant factor. Therefore, applying the data herein reported to Davis dimensionless groups, the following correlation was obtained and is recommended as the best approach to evaluating the heat transfer coefficients in annular spaces.

hD₁/k = 0.0158[D₁G/μ]^0.8[Pr]^1/3[μ/μW]^0.14[D₂/D₁]^0.15

Davis reported a constant of 0.038. The above equation related. 60 adiabatic heat transfer coefficient determinations, with an average deviation of ±8.4%.

A dimensional correlation was also developed which follows the experimental data with an average deviation of ±10%.

h/k = 0.0145[W/Aμ]^0.8[Pr]^0.4[D₂/D₁]^0.2

Recommended Citation

Levine, Jacob, "Evaluation of heat transfer coefficients for annular spaces" (1960). Theses. 2976.
https://digitalcommons.njit.edu/theses/2976