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Show The approach taken in establishing the size of the modified unit has been to maximize its generating capacity, consistent with making maximum use of existing plant infrastructure. Key plant performance parameters are summarized in Table I. Thermal Coal Heat Input Cooling Tower Load Generator Output Auxiliary Load Net Unit Generation Net Unit Heat Rate Environmental S02 NOx Particulates Table I - UNIT 1 PERFORMANCE PARAMETERS (Preliminary ) MMBtu/hr MM Btu/hr MWe MWe MWe BtuJkWh IblMM Btu IblMM Btu IblMM Btu Existing 400 216 35.6 2.2 33.4 12,000 6.0/ 1.6(·) - / 0.5(·) 0.19/0.19(·) POCTF 440 215 54.6 6.7 47.9 9,186 0.1 to 0.2 0.1 to 0.2 0.01 (*) pre/post Phase II Clean Air Act Amendments (2000) Change + 100/0 + 430/0 -23% / - 90% / -70% / - 95% By leveraging the significant improvement in heat rate offered by the Kalina cycle with a modest 10% increase in coal heat input, the unit output will be increased a substantial 43% to about 48 MWe, with a corresponding 23% decrease in heat rate. At the projected net unit heat rate of about 9,200 BtulkWh, the modified Whitewater Valley unit 1 will be the most efficient coal-fired unit of its size in the U.S. The planned project, in fact, compares favorably to the best coal-fired unit heat rate reported in the USA in 1994 of 8,889 BtuJkWh (annual average) for a 660 MW supercritical unit. Equipment: To date an initial feasibility study for the project has been completed, and the preliminary design is in progress. Highlights of this on-going project conceptualization are described below. Because the Kalina cycle optimizes at different thermodynamic conditions than a steam cycle, and because of the change in working fluid and the increase in generating capacity, the complete steam side of the power cycle is to be removed and replaced. These systems include the boiler and auxiliaries, turbine-generator and auxiliaries, condenser, condensate system and feedwater system. The size of the unit has been selected such that the new vapor generator will fit in the existing boiler support-steel cavity, and the new turbine-generator will fit the existing turbine pedestal (after pedestal modification). The fact that the Kalina cycle regenerates substantially more heat than a steam cycle results in a ·significant increase in the number of regenerative heaters, such that a turbine hall addition will be required to house this new equipment. The vapor generator, or boiler, design for the POCTF is a single reheat, drum type with pumped circulation for cooling furnace wall evaporative tubes. The Kalina cycle, with its higher rate of heat regeneration, requires less evaporation but more superheater and reheater duty in the vapor generator. Thus, in addition to pendant and horizontal superheater and reheater surfaces, in the preliminary design portions of the upper furnace walls are used for superheating and reheating the working fluid. The design of these sections is the same as conventional radiant wall reheater designs. The vapor generator looks very much like a large utility unit designed for a Rankine cycle. Turbine design performance for a Rankine or Kalina cycle is very similar. Ammonia has a molecular weight very close to that of pure water, (17 vs. 18). This allows the use of current designs for turbine blading and turbine shell to be used in a Kalina cycle. One major difference in the turbine, when used in a Kalina cycle, is that the turbine is |
