Heat and Mass Transfer

tm = mean temperature difference between the two fluids for counter flow heat exchanger,
tm = th1-tc2 = th2-tc1.
tm = th2-tc1 = 60-40 = 20.

This term refers to the temperature difference between the leaving process fluid and the entering service fluid.

A regenerative heat exchanger, or more commonly a regenerator, is a type of heat exchanger where heat from the hot fluid is intermittently stored in a thermal storage medium before it is transferred to the cold fluid..

In a shell and tube heat exchanger, baffles are provided on the shell side to Improve heat transfer And Provide support for tubes and Prevent stagnation of shell side fluid.

The fouling factor represents the theoretical resistance to heat flow due to a build-up of a layer of dirt or other fouling substance on the tube surfaces of the heat exchanger.

Heat Flow occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature.

Fourier’s law of heat conduction is valid for One dimensional cases only
Fourier equation is valid for all matter solid, liquid or gas. The vector expression indicating that heat flow rate is normal to an isotherm and is in the direction of decreasing temperature.

The natural convection air cooled condenser are used in small capacity applications such as domestic refrigerators, freezers, water cooler and air-conditioners.

The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to -1/3.

Radiation is the process of heat transfer in which heat flows from a Hot body to cold body in a straight line, without affecting the intervening medium.