Mathematical Method for Estimating the Optimal Work of the Thermal Power Plants Cooling System

摘要

Economic work of modern power plants with condensing steam turbine greatly depends on the perfection of the steam cycle, i.e. on their thermal efficiency η_t. Decreasing the steam pressure at the exit of turbine (the condensation pressure) p_k is one of the possibilities for improving steam cycle perfection, because that reduces the quantity of heat what is transferred to the environment. Maintenance of low condensation pressures is realised by steam condensation in vacuum. Because of that, the heat of the condensation ought to be continually taken away, usually by water circulating across the condenser. With a decrease in the condensation pressure, the quantity of heat that ought to be taken away increases. So although reducing the condensation pressure increases the produced power, it also increases energy consumption in the cooling system for driving the circulating pumps. This causes an increase of the auxiliary energy consumption in the power plant, so the power plant overall efficiency may be reduced although the thermal efficiency is increased. Because of that, the correct choice of the working regime of the condensation system, i.e. the cooling system is very important for the economic work of the power plant.