NASH condenser exhauster packages are used in steam cycle plants to efficiently remove inward air leakage from the condenser. The effect is to provide lower turbine backpressure, improve heat rates and reduce generating costs.
The packages typically consist of a liquid ring vacuum pump (either a two stage vacuum pump or a single stage vacuum pump with air ejector), air-liquid discharge separator, heat exchanger and associated controls.
NASH condenser exhauster packages perform reliably, operate automatically and hold the condenser at the best possible vacuum during unexpected transients of air leakage.
To realize a low absolute pressure, two stage liquid ring vacuum pumps are the perfect solution. They offer a low absolute pressure with a small and compact system design. Two stage vacuum pumps work best with water cooled condensers.
Capacity Bonus: You get more capacity and save energy when water vapor is condensed ahead of the NASH liquid ring vacuum pump. This performance bonus is made possible by NASH conical porting.
Since more than two-thirds of the gas drawn from the condenser is water vapor, the NASH conical ported design is ideal for handling this air-vapor mixture. Spray water condenses a substantial portion of the vapor ahead of the pump and, as that condensate passes through the pump as a liquid, pumping capacity is increased and energy saved. This “NASH capacity bonus” is not possible with other pump designs.
The operating pressure of an air-cooled condenser is a function of the air temperature, not the cooling water temperature. The performance characteristics of the liquid ring pump and air-jet package allow it to track the condenser pressure over the entire range of cooling water temperatures.