Temperature of POC
In heat utilization, it must be born in mind that heat carried by POC is not available. Heat carried by POC, i.e. H_POC

where T_POC is the temperature of POC leaving the furnace. The temperature of POC can be related with the process critical temperature. The process critical temperature is the temperature at which a process can be carried out. POC must exit at the critical process temperature. A POC temperature lower than critical process temperature means that some portion of the furnace is cooler than the rest, whereas POC temperature greater than critical process temperature means overheating of some portion in the furnace. Overheating will cause increase in fuel consumption.