Question

4. Answer the below questions:

i. When the convection heat transfer between a solid surface and the adjacent fluid will be by pure conduction?

ii. Why Its not recommended to use steam in same direction versus products in heating/coolig by heat exchangers?

Answer 1

1.

Convection is the mode of energy transfer between a solid surface and the adjacent liquid or gas that is in motion, and it involves the combined effects of conduction and fluid motion. The faster the fluid motion, the greater the convection heat transfer. In the absence of any bulk fluid motion, heat transfer between a solid surface and the adjacent fluid is by pure conduction. The presence of bulk motion of the fluid enhances the heat transfer between the solid surface and the fluid, but it also complicates the determination of heat transfer .Convection is Conduction with fluid motion

2.Heat exchanger is a system used to transfer heat between two or more fluids.They are used in both heating and cooling processes