Energy Saving Transformation And Practice Of Unit Equipment In Sanhe Power Plant

Energy is the foundation of a country’s national economic development and is crucial for the development of national economy.In recent years,the problem of energy in China is becoming more and more outstanding.The national requirements for energy-saving and emission reduction in thermal power plants are also increasingly strict.Many scholars at home and abroad have carried out a lot of research and implementation of energy-saving transformation of the unit,proposed many energy-saving renovation programs and achieved remarkable results.In order to respond positively to the national requirements for energy conservation and consumption reduction,Sanhe Power Plant has carried out energy-saving renovations for the first and second-stage units and proposed various transformation schemes for different locations.After the comprehensive analysis,the optimal program was selected for implementation.The transformation of the site involves turbines,air preheaters,low-temperature economizers,and induced draft fans.For the 300MW Dongfang Electric Group production of sub-critical,an intermediate reheat,double-cylinder double exhaust,heating extraction,impulse turbine generator unit capacity increase to 315MW energy-saving transformation.The speed ratios and enthalpy values at all levels have been optimized.The profile of the blade has been optimized for different pressure levels.The proper steam seal structure is used for the high,medium and low pressure-cylinders,and the degree of perfection of the flow through section of the turbine is improved.After the energy-saving transformation,the unit’s heat consumption has greatly decreased,and the unit’s safety has also greatly improved.The three-bay air preheater model No.3 and No.4 of LAP10320/2200 was sealed and reformed using flexible contact sealing technology.The air leakage coefficient of the air preheater is significantly reduced after sealing and the resistance on the flue gas side is also reduced,and the safety and progress of the unit are improved.Due to the high temperature of the exhaust gas from the unit,low-temperature economizers were installed on＃1～#4 units,and different low-temperature economizer water intake schemes were proposed according to the different needs of the first-phase and second-phase units.The modular tube structure adopted by the device makes the installation and maintenance work easy and simple,which greatly reduces the impact of equipment failure on the operational safety of the unit.After the installation of the low-temperature economizer,the smoke temperature of the low-temperature economizer outlets of Units#1 and#2 in the first phase is about 105℃,and the smoke temperature at the outlet of the low-temperature economizers of Units#3 and#4 is stable at 90 to 100℃.The stable control of the smoke temperature at the outlet has reduced the coal consumption under different loads before the transformation.Because the total resistance of the wind turbine system after the energy-saving transformation is relatively large,the fan system of the thermal power plant cannot meet the requirements for the full-load operation of the unit after the transformation.Therefore,the existing fans of#1～#4 units are to be expanded.Considering the actual conditions of the power plant,the needs of the capacity expansion of the wind turbine,and the safety of the generator set,the No.1 and No.2 units will be combined to increase their capacity,and the No.3 and No.4 units will be increased in capacity and efficiency.Performance test of the air-purifier after energy-saving was performed.A series of parameters such as the total pressure efficiency of the fan before and after the energy-saving transformation,the volume flow of the fan,and the efficiency of the fan were compared.It can be seen that the effect obtained after the energy-saving reform is significant.After this energy-saving transformation,the economic and safety of Sanhe Power Plant units have been greatly improved,and the energy saving and consumption reducing effects have been significant.The energy-saving renovation has accumulated a lot of experience,but also provides effective data and plans for energy-saving transformation of other power plants.