HiETA Successfully Tests a Waste-Heat Heat Exchanger
The steam superheater heat exchanger is made from Inconel 625, a nickel super alloy with an operating temperature of up to 800°C and a fluid medium of air to liquid with a phase change on the liquid side.
In this evaporator unit, the condensate water extracted from the flue gas is pumped through highly enhanced evaporator inner tubes with flue gas passing over the tube to generate superheat steam of up to 500°C and 36 bar. The superheater heat exchanger was tested with an airside max temperature of 650°C.
The benefit of a system such as this is twofold. Firstly, the generated superheat system is used in steam turbines for generating power, thus increasing the efficiency of the cycle thermal. Secondly, the drop in flue temperature (~200°C) in evaporator allows the use of highly effective smaller condenser units for removing water vapour in the flue gas.
The boiler waste heat exchanger is part of HiETA’s novel waste heat recovery system, which also features our ultra-compact highest effectiveness (>96%) heat exchanger, and is highly effective for removing water vapour in the flue gas.