System for fuel gas moisturization and heating

摘要

Embodiments of the present invention may provide to a gas turbine a fuel gas saturated with water heated by a fuel moisturizer, which receives heat form a flash tank. A heat source for the flash tank may originate at a heat recovery steam generator. The increased mass flow associated with the saturated fuel gas may result in increased power output from the associated power plant. The fuel gas saturation is followed by superheating the fuel, preferably with bottom cycle heat sources, resulting in a larger thermal efficiency gain.

主权项

1. A system comprising:
a power plant comprising:
a gas turbine comprising a compressor, a combustion system, anda turbine section which collectively generate an exhaust; anda HRSG comprising a heat-exchanging section that receives the exhaust and evaporates water into steam; a fuel moisturizer that creates saturated fuel gas, comprising:
an inlet comprising piping that receives water at a first temperature;a fuel gas inlet comprising piping that receives the fuel gas in an unsaturated or a dry condition;a direct contact heat and mass transfer area that mixes the water and the fuel gas to create saturated fuel gas;an outlet that discharges the water at a second temperature, which is lower than the first temperature; wherein the water flows through associated piping to the HRSG; anda fuel gas outlet comprising piping that discharges the saturated fuel gas; a flash tank comprising:
a supply comprising piping that receives water from the HRSG;a steam outlet comprising piping that discharges steam generated within the flash tank;a discharge comprising piping that connects to the inlet of the fuel moisturizer, allowing water to flow from the flash tank to fuel moisturizer; andwherein the flash tank rapidly reduces the pressure of the water received from the supply, causing a portion of the water to flash to steam, which discharges out the steam outlet, and causing the remaining portion of the water to flow to the fuel moisturizer via the discharge; and a fuel superheater comprising:
a water supply comprising piping that receives water at a first temperature from the HRSG;a fuel gas inlet comprising piping that receives the saturated fuel gas from the fuel moisturizer;a heat exchanging area that allows heat to transfer from the water to the saturated fuel gas, operatively creating superheated, saturated fuel gas;a water discharge comprising piping that discharges the water at a second temperature, anda fuel gas outlet comprising piping that discharges the superheated, saturated fuel gas.