Research On Operating Characteristics Of 200MW Heller Indirect Air-Cooled Triangle

The indirect air cooling unit consumes less water for power generation.The development of indirect air cooling technology can effectively solve the water shortage problem faced by thermal power plants.Therefore,the indirect air cooling technology has great application prospects in "rich coal and poor water" areas.The air cooling tower is an important part of the indirect air cooling unit,and its performance directly affects the safety and economy of the air cooling unit.Taking the air-cooled triangle of a 200 MW Heller type indirect air-cooled unit in a power plant as the research object,according to the circulating water heat exchange process,the influence of factors such as wind speed and air temperature on the aircooled triangle heat transfer performance was studied.Based on the full analysis of circulating water and wind,the research object is divided into wind speed system,fluid network system and heat exchange system.Based on the research purpose and characteristics of simulation modeling,reasonable assumptions and simplifications are made,and mathematical models are established for each system.The lumped parameter method was used to establish the wind speed profile model,parallel pipe network flow distribution model and heat exchanger model,and the mathematical model was compiled into the computer language and imported into the platform algorithm library through Fortran language to complete the system real-time simulation model.Based on the established simulation model,in the static characteristic simulation experiment research,the heat transfer capacity of the air-cooled triangle and the change law of the circulating water outlet temperature under the single variable change were analyzed.The simulation model was verified with the historical operation data of the power plant.The results show that the simulation results of the model are consistent with the historical operating data of the air-cooled triangle,and the maximum gap between the simulation results and the historical operating data is 10%,which is within the tolerance range;the circulating water outlet temperature of the air-cooled triangle decreases with the decrease of air temperature,and with the air The flow velocity increases and decreases.When the air-cooled triangle is operated at an ambient temperature of-15 ° C and a wind speed of 6 m / s,the air-cooled triangle tube bundle is in danger of freezing.When the power plant load is 129.4MW,an air-cooled triangle dynamic characteristic simulation experiment is performed.The variation of the operating parameters of the simulation model when the three parameters of air-cooled triangle inlet wind speed,air-cooled triangle inlet wind temperature,and air-cooled triangle circulating water inlet temperature are given a single variable step disturbance are discussed.The results show that the temperature step of the air cooling triangle becomes smaller,and the temperature of the air cooling triangle begins to decrease at the same time.Among them,the cycle time of the water cooling triangle inlet section of the air cooling triangle is the shortest,and the overall time of the air cooling triangle is 210 s.Changing hours is similar to the wind temperature step change.The air cooling triangle’s overall steady-state recovery time is 180 s.When the air-cooling triangle circulating water temperature step is small,the temperature change of each section of the air-cooling triangle has a certain delay.The simulation results are consistent with the historical operating data of the power plant.This model can provide a reference for the safe and economic operation of air-cooled towers and provide guidance for shutter control strategies.