## Solution for Engineering Heat Transfer 2nd Edition Chapter 3, Problem 1

by William S. Janna
196 Solutions 12 Chapters 15999 Studied ISBN: 9780849321269 5 (1)

# Chapter 3, Problem Example 1 : Example 3.1 A concrete driveway is...

Example 3.1

A concrete driveway is 4.2 m wide. Within the concrete slab are 1 standard type K copper tubes through which heated water is pumped to keep the concrete warm during winter months. Snow that falls or ice that forms on the concrete will melt and flow of€ the surface. The copper tubes are 6 cm apart (center to center), and the line of centers of the tubes is 4 cm below the slab surface,

as shown in Figure 3.10. Water within the tubes heats each tube surface to 85°C. The concrete surface should be at least 0°C. The ground beneath the slab is also at 0°C. Determine the heatflow rate from one tube at this location.

## Step-By-Step Solution

Example 3.1

Solution

Heat flows from each pipe to the upper and lower surfaces. As fluid flows through the pipes, the fluid temperature may change with length (for example, into the page). We are concerned only with the section where the temperatures shown in Figure 3.10 apply.