Heating the feed water to an HRSG or other boiler as efficiently as possible is of paramount importance to a CCGT plant and the overall efficiency.
Heat is usually taken from the cycle at different points to minimise the parasitic loads. Very close temperature approaches are used to maximise the heat input into the feed water. Traditional shell and tube heat exchangers have an optimum design point of approximately 8°C (14°F), and are operating much below this where the heat transfer area grows exponentially with temperature approach. (graphic required to demonstrate)
The robust FPHE and Hybrid from Heatric have a much lower pinch point, typically 3°C (5°C) so can achieve a far higher heat recovery for a given heat transfer area, greatly reducing the foot print, weight and the structural steel required for the installation.