Analysis And Selection Of Design Scheme Of Steam-Water System For Cogeneration Unit

Cogeneration is a form of advanced energy use that produces both electricity and heat.In the power generation process,a lot of heat takes away by recycling water emissions into the atmosphere in vain.Most of the heat energy used is low temperature heat at different temperature.Heat energy of fuel combustion was the main source of low temperature heat energy,and the available energy loss is very significant.Cogeneration in accordance with the grade of heat energy cascade utilization,with significant energy saving effect.China’s government attaches great importance to the development of cogeneration,policy-oriented restrictions and the elimination of direct coal-fired heating,strongly support for combined heat and power.Dandong’s construction of cogeneration is very early,but development is slow.Into the new century,the urgent need of transform the old Dandong heating system,which proposed Jinshan cogeneration construction projects.China Huadian Corporation takes over the project construction,at the research meeting will require the project should be in accordance with the Group’s new thermal power project management approach,according to "China Huadian Corporation thermal power plant design optimization guidance" to carry out design optimization selection.This paper is to the design selection of steam water system optimization constitutes.This paper describes the development of combined heat and power,describes the project background and situation of Dandong Jinshan cogeneration project,analyzes and calculates the heat supply status and project heat load of Dandong City,introduces the engineering equipment selection and thermal system situation.The optimal design and selection of partial steam-water system design,including selection of steam turbine steam seal,optimization of main steam and reheat steam system and high-pressure feed water system and optimization of condensate pump configuration.In the steam seal selection,the honeycomb seal performance,installation requirements are moderate,the steam quality requirements are moderate,and the future power plant production conditions.The main steam pipes are analyzed with emphasis on the properties of new steels and their influencing factors.The A335 P91 steel is used for the main steam pipes,A335 P92 steel for the hot reheat steam pipes,A672 B70 CL32 steel for the cold reheat steam pipes,pipe WB36 steel for the water supply.Condensate system configuration to fully consider the need for production operation reliability and economy,and finally determine the configuration of the condensate pump with "3 × 50%capacity condensate pump plus frequency converter"(drive for a drag two + one drag first,the inverter capacity and a single condensate pump motor capacity corresponds to the program.)...