The energy lost in waste gases cannot be recovered completely.However, much of the heat could be recovered and loss minimized.Depending upon the type of process, waste heat can be recovered at virtually any temperature from that of chilled cooling water to high temperature waste gases from an industrial furnace or kiln.
The advantages of waste heat recovery are it can reduce facility’s annual fuel bills, reduce plant emissions and improve productivity.
In process heating, using waste heat will displace a portion of the fuel or electricity that would otherwise be purchased.
Above 1,800o F (982o C), stack losses will consume at least 50 percent of the total fuel input to the process.
Equipment used for waste heat recovery: The variety of equipment available for waste heat recovery includes recuperators, regenerators and waste heat and exhaust gas boilers/steam generators.
Waste heat recovery is always a good idea when: The temperature of the waste heat is hotter than the input requirements of the process.
The fuel savings achieved are greater than the capital and operational costs of the waste heat recovery equipment.
As a result, the specific steam consumption of turbine will also come down and consequently the overall efficiency of the whole system is improved.
Chapter 1: INTRODUCTIONWaste heat is heat which is generated in a process by fuel combustion or chemical reaction, and then “dumped” into the environment even though it could still be reused for some useful and economic purpose.
So, there is an inevitable need to solve this problem and make sure that the efficiency of the industry is increased.
High temperature heat recovery potential is available in many industries.