The heat recovery system extracts the thermal power from the exhaust of the engines or turbines to feed the ORC module via an intermediate loop of heat recovery. The intermediate fluid, which is usually oil, transfers heat to the organic fluid in the ORC evaporator, where the organic fluid vaporizes. The vaporized fluid then flows to the turbine. Here the vapour expands causing the turbine to spin and creating electricity in the generator. The vaporized organic fluid then continues through the cycle to the condenser where it transforms into liquid, ready to be processed by the pump before beginning the cycle again.
The conventional ORC solution as described above employs an intermediate heat transfer loop that offers some advantages over steam technology but leads to a more complex plant design and requires
the use of flammable fluids at the interface with the hot flue gas which instead is not necessary with steam technology.
EXERGY’s R&D activities on WHR systems are today focusing to give an answer to this gap with an innovative ORC configuration (patent pending) combining the benefits of steam technology and ORC technology.