When a solid,liquid or gas has to be heated up or cooled down a heat exchanger is used. In a heat exchanger a hot fluid(e.g. hot water or steam) is used to heat a cooler fluid.
The two fluids will be separated by some physical barrier such as a tube wall or a metal plate. The aim of a heat exchanger designer is to make sure that the area of the tube walls or metal plate is large enough for the required amount of heat to be transferred from the hot fluid to the cold fluid.
The performance of a heat exhanger will normally be specified in terms of the inlet and outlet temperatures of one of the two streams entering the exchanger. The amount of heat that has to be transferred between fluid streams is called the heat load.
The heat load is calculated using the First Law of Thermodynamics and a thermodynamic peroperty called the specific heat capacity. |
