CONDUCTION HEAT TRANSFERHeat TransferQQAQ2 p ro L5.92 x 105Btuhr2 (3.14) (0.54 ft) (35 ft)4985Btuhr ft2Example:A 10 ft length of pipe with an inner radius of 1 in and an outer radius of 1.25 in has anouter surface temperature of 250°F. The heat transfer rate is 30,000 Btu/hr. Find theinterior surface temperature. Assume k = 25 Btu/hr-ft-°F.Solution:Q2 p k L(ThTc)ln(ro/ri)Solving for Th:ThQ ln(ro/ri)2 p k LTc30,000Btuhrln1.25 in1 in2 (3.14)25Btuhr ft °F(10 ft)250°F254°FThe evaluation of heat transfer through a cylindrical wall can be extended to include a compositebody composed of several concentric, cylindrical layers, as shown in Figure 4.HT-02 Page 14 Rev. 0
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business