Computer modeling of lime-soda softening of cooling waters

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6815811

Chen, J C.Y.

A computer model is developed to fully describe the lime soda ash softening process. This process has a long history of being used to remove calcium and magnesium hardness from cooling waters in order to prevent scaling on heat exchangers. Softening of makeup water and/or a sidestream from the recirculating water will allow a reduction in blowdown. In the extreme case, zero blowdown may be accomplished to conserve cooling waters and to save the costs of disposing of blowdown. Cooling waters differ from most natural waters in having higher temperature and higher concentration of dissolved solids, and, therefore, a higher ionic strength. These factors plus the effects of complex formation are taken into consideration in the development of the computer model. To determine the composition of a softened water, the model assumes that an equilibrium state is reached in a reactor, and employs the equations of mass action and mass balance. The resulting nonlinear simultaneous equations are then linearized by Taylor series expansion and solved by the multidimensional Newton-Raphson method. The computer predictions are compared to the results of laboratory studies using synthetic waters.

• Research Organization: Northwestern Univ., Evanston, IL (USA)
• OSTI ID: 6815811
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
BLOWDOWN
CONTROL
COOLING SYSTEMS
CORROSION PROTECTION
ENERGY SYSTEMS
HEAT EXCHANGERS
MATHEMATICAL MODELS
REACTORS
WATER COOLED REACTORS
WATER TREATMENT