Table 2: Nomenclature.

Parameter DescriptionUnit

Temperature of the fluid entering the systemK
Temperature of the fluid leaving the systemK
Mass flow rate of the fluidkg s-1
Specific heat capacity of the fluid at constant pressurekJ kg-1K-1
Inner diameter of the heat exchanger pipem
Outer diameter of the heat exchanger pipem
Thermal conductivity value of the pipe wall materialW m-1K-1
Heat transfer coefficient of airW m-2K-1
Heat transfer coefficient of waterW m-2K-1
Surface area of the heat exchanger wallm2

The subscript refers to the initially hotter fluid, and the subscript refers to the initially colder fluid.