Application Study On The Peak Condenser In 600MW Air Cooling Unit

Air-cooled units can solve water shortages and reduce pollution,and are widely used in coal-fired power plants.However,with the air-cooled unit put into operation more common,the shortcomings of air-cooled unit gradually appear.Especially in summer,the ambient temperature is high and the unit vacuum is too low,affecting the air-cooled unit safety and economy.Aiming at the problem of back pressure fluctuation in 600 MW air-cooled unit,this paper will transform its direct air-cooling system to reduce the summer full-back pressure,reduce the cost of power generation,improve the safety and economy of the unit.This paper analyzes the operation status of the air cooling system and the auxiliary wet and cold system of 600 MW air cooling unit.According to the technical accounting,in the summer operating conditions,into the peak cooling system,the air cooling system can be extracted from the 240t/h lack of steam,so that the turbine back pressure from 30 kPa to 23 kPa.For the connection of the peak condenser in the auxiliary cooling water pipeline,the advantages and disadvantages of the two schemes are shown in terms of heat balance,technical parameter calculation and technical scheme.Under the summer condition,the back pressure operation of the pump turbine after the transformation of the series scheme is lower than that of the parallel scheme,but the series scheme has a great influence on the resistance of the system.But from the security point of view,the preferred use of tandem arrangement.In order to increase the heat dissipation capacity at the cold end,the top and lateral inlet steam of the peak system are analyzed.Fluent software simulation results show that the lateral inlet tube arrangement is arranged so that the heat load distribution is uniform and the flow field is smooth and can run without water to ensure the safety and reliability of the unit operation.And summarizes the measures such as the transformation,precautions and accident handling of the side inlet steam condensate and other thermal system.The transformation of Unit 6 was carried out.Through the test and data processing analysis of two test cases,the vacuum change was obvious,the deviation is about 6.58 kPa,the heat consumption is reduced by 207.25kJ/(kW·h),the unit is reduced by about 7.09g/(kW·h),and the effect of Unit 6 with peak condenser is obvious.Finally,in order to ensure the normal operation of the unit with the peak condenser installed in the winter,the operation of the peak condenser unit and the same time not put into operation units for comparative analysis.It was found that the air-cooled radiator may have a risk of freezing when the ambient temperature is below-15°C and the load is below 350 MW.At this point the fan running number and frequency of air-cooled should be adjusted timely based on air-cooled condenser and suction port temperature,if necessary,reverse counter-current fan to ensure safe operation of the unit.