Waste Heat Recovery Units

A waste heat recovery unit is an energy recovery heat exchanger which recovers heat from hot streams with prospective high energy content like hot flue gases from a diesel generator or steam from cooling towers or even waste water from various cooling progressions such as steel cooling.

Waste heat found in the exhaust gas of different progressions or even from the exhaust stream of conditioning unit can be employed to preheat the inward bound gas. This is the primary methods for recovery of waste heat. Many steel making plants employ this process as an economic method to augment the production of the plant with lower fuel demand. There are various commercial waste heat recovery units for the transferring of energy from hot medium space to lower one.

The concept of heat recovery units

Recuperators are those types of heat exchangers where the exhaust gases are passed through, comprising of metal tubes that carry the inlet gas and thus preheating the gas before entering the process. The heat wheel is an example which operates on the concept as a solar air conditioning unit. Regenerator is an industrial unit which recycles the same stream after processing. In this type of heat recovery, the heat is regenerated and recycled in the processes.

Heat pipe exchangers and thermal heat

Heat pipe exchangers are better thermal conductors that have the capacity to transfer heat hundred times more than copper. Heat pipes are notable in renewable energy technology as being employed in evacuated tube collectors. The heat pipe is majorly employed in space, process or air heating, in waste from a process is being transferred to the adjacent due to its transfer mechanism. Thermal wheel or rotary heat exchanger includes a circular honeycomb matrix of heat absorbing material that is slowly rotated inside the supply and exhaust air streams of an air handling system.

Process boilers and run around oil

In the event of process boilers waste heat in the exhaust gas is passed along a recuperator which bears the inlet fluid for the boiler and therefore reduces thermal energy intake of the inlet fluid. Heat pumps are used for organic fluids that boil at a low temperature means that energy could be regenerated from waste fluids. Finally, there are run around oil that consist of two or more multi-row finned tube coils connected to each other by a pumped pipe work circuit. Thus waste heat recovery units benefit in many aspects for various industries in contemporary times.

Questions:

• What are waste heat recovery units?
• List some of the advantages of waste heat recovery units.