Enhanced Condenser Venting for Condensate Oxygen Control
ABSTRACT
Existing steam condenser venting equipment is often undersized, improperly installed or required to operate beyond its capabilities. The recent trend to part load operation, caused by market conditions, has accentuated the problem.
Inadequate venting equipment retains air in the condenser, which may raise the condenser pressure and will increase the absorption of oxygen in the condensate.
Conditions which contribute to inadequate venting are described and the characteristics of the two most common venting devices, steam ejectors and liquid ring vacuum pumps, are discussed.
A hybrid system which will permit condenser operation at low absolute pressure and will reduce dissolved oxygen in the condensate is described.
INTRODUCTION
The addition of large, more efficient Nuclear and Fossil plants, combined with reduced power consumption, cogeneration, and a host of other factors, increasingly imposes cycling or two-shift operation of existing units originally designed for base load operation.
This daily cycling, nightly and weekend shutdown, often requires part load steam condenser operation with consequent low operating pressures.