working regime of power plant cooling system, i.e. optimal pressure in condenser in .... Optimal cooling water flow, at which optimal vacuum in condenser is ...
PROCEEDINGS OF WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY VOLUME 5 APRIL 2005 ISSN 1307-6884
Method for Optimal Control of Power Plant Cooling System Igor Nedelkovski, Ilios Vilos, Tale Geramitcioski condensation ought to be continually taken away. Heat of condensation is taken away by water circulating across the condenser. With condensation pressure decreasing the quantity of heat that ought to be taken away in the condenser increases, which demands more intensive circulation of water in power plant cooling system. So, besides that reducing of the condensation pressure increases produced power, it also increases energy consumption in cooling system for driving circulating pumps. This causes increasing of auxiliary energy consumption in the power plant, so the power plant overall efficiency can be reduced although the thermal efficiency is increased. Because of that, the regular 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.
Abstract—In this paper a method for estimation the optimal
working regime of power plant cooling system, i.e. optimal pressure in condenser in function of power plant working regime is presented. This method is based on the estimation of working characteristic of the cooling system in global. The working characteristic of the cooling system is formed on the base of characteristics of the elements that make cooling system. The procedure and principal scheme of system for regulation of the work of the cooling system are also presented.
Keywords—Optimal, control, power plant, cooling.
M
I. INTRODUCTION
ODERN power plants are complex systems with high power. Their work depends on many parameters. Any, even the smallest improving of their work leads at significant energy saving. Actual world tendency for energy saving, causes need to take care for all parameters which can enable economic work of the power plants. 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 ηt. Decreasing of the steam pressure at the exit of turbine (the condensation pressure) pk is one of the possibilities for improving steam cycle perfection, because that reduces quantity of heat that is transferred to the environment. Influence of the condensation pressure on the power plant thermal efficiency (for RankineClausius cycle) can be analyzed from fig.1, where in general form this dependence is presented. Function ηt(pk) is obviously decreasing in whole interval in which is defined, i.e. dηt/dpk
