Page 378 - Handbook of Energy Engineering Calculations

FIGURE 5 Dual-flash process extracts up to 30 percent more power
than older, single-flash units. (Power.)

Steam is cleaned in two trains of scrubbers, then expanded through a 54-

MW, 3600-rpm, dual-flow, dual-pressure, five-stage turbine-generator to
produce 48.9 MW. Of this total, 47.5 MW is sold to Southern California
Edison Co. because of transmission losses.
The turbine exhausts into a surface condenser, coupled to a seven-cell

cooling tower. About 40,000 lb/h (18,000 kg/h) of the high-pressure steam is
required by the plant’s air ejectors to remove NCGs from the main condenser
at a rate of 6500 lb/h (2925 kg/h).
Because the liquid brine from the flash process is supersaturated, various

solid compounds precipitate out of solution and must be removed to avoid
scaling and fouling of the pumps, pipelines, and injection wells. This is
accomplished as the brine flows to the crystallizer and clarifier tanks where,
respectively, solid crystals grow and then are separated. The solids are

dewatered and used in construction-grade soil cement. The clarified brine is
disposed of by pumping it into three injection wells.

Related Calculations. Geothermal generating plants are environmentally
friendly because there are no stack emissions from a boiler. Further, such