In many process industries thermal utilities like Thermic Fluid heaters, boilers etc. are added as per need of expansion i.e. in unphased manner. Locations for such utilities are not earmarked and thus they are located near user end.
In many process industries, mechanical utilities like HVAC, Air Compressors, Refrigeration etc. are added as per the expansion happens or as per user location. Such decentralised operation of mechanical utilities has issues like Part load operation, lack of redundancy etc..
Designing of entire chemical factory is a very complex assignment as it requires strong knowledge base and expertise of designing for processes, process equipments (reactors, heat exchangers, tanks, vessels etc.), utilities (pumps, compressors, cooling towers, fans, boilers, hot water generator, thermic fluid heater, hot air generators), mechanical equipments (conveyors, elevators, etc.), unit operations (Drying, separation, sieving, filtration, sedimentation, de husking etc.), Solvent recovery system, Effluent treatment plant, electrical and instrumentation, piping , installation and commissioning.
A waste heat recovery unit (WHRU) is an energy recovery heat exchanger that recovers heat from hot streams with potential high energy content, such as hot flue gases from a diesel generator, sinter cooler, shaft furnace etc. The heat recovered is used for preheating the charge generating chilled water, preheating water / combustion air etc.