heat recovery

Heat recovery is the transfer of heat from a high temperature source (gas or liquid) to a lower temperature source. Many industrial processes produce waste heat. Processes include the waste heat in exhaust gases from boilers and ovens, the heat from effluent and the condenser in a refrigeration plant. Heat recovery uses various techniques and methods to capture and recycle this waste heat and in doing so reduces the energy consumption and associated emissions.

The most popular and cost effective way is to reuse the heat in the process from which the heat originates. Other methods include using the heat within another process or using the waste heat for space heating and hot water.

The type of heat recovery technology to use will depend on the source of the waste heat and how it is to be used. The main technologies are:

• Gas to gas heat exchanges
• Gas to liquid heat exchanges
• Liquid to liquid heat exchanges
• Heat pumps

As a first step a site survey should be carried out to determine the suitability of heat sources available. As part of the survey the temperature, quality and location of available heat sources and where they might be successfully utilized need to be measured and identified.