660MW直接空冷凝汽器传热特性及运行优化

发布时间：2018-06-20 01:15

本文选题：直接空冷 + 凝汽器　；参考：《华北电力大学》2014年硕士论文

【摘要】：直接空冷凝汽器,是利用周围空气来冷凝排汽的,其冷却空气由大直径轴流风机提供,空冷风机的运行工况会对凝汽器产生很大的影响。空冷风机的不同运行方式,会直接影响到厂用电量以及机组出力,影响机组的供电标准煤耗率。因此,随着机组工况及环境参数的变化,灵活调控空冷风机的运行方式,使风机在不同环境工况下都能以最优的方式运行,保证空冷机组的安全与经济运行。本文对发电厂空冷系统进行了详细的介绍,通过凝汽器传热模型分析以及排汽压力计算,研究了排汽热负荷、空冷单元入口空气温度以及迎面风速对凝汽器压力的影响规律,得到了空冷凝汽器的变工况特性;同时论述了空冷风机的运行特性,并以某660MW直接空冷机组为例,计算分析了风机不同运行方式对凝汽器压力的影响。对某660MW超临界直接空冷机组空冷岛进行了优化运行试验。试验中,在不同机组负荷及环境温度下,通过改变空冷风机频率,得到了不同风机运行方式下的排汽压力、机组出力、空冷岛耗功以及机组净功率。通过比较分析,获得了不同工况下的风机最优运行方式和机组最佳控制背压,可为直接空冷机组风机群在不同环境参数、负荷下的经济运行调节提供了参考。
[Abstract]:The direct air-cooled condenser uses the surrounding air to condensate and exhaust steam. The cooling air is provided by a large diameter axial fan. The operating conditions of the air-cooled condenser will have a great impact on the condenser. The different operation modes of the air cooler will directly affect the power consumption of the plant and the output of the unit and the standard coal consumption rate of the power supply unit. Therefore, with the change of unit working conditions and environmental parameters, the operation mode of air cooler can be adjusted flexibly, so that the fan can operate in the best way under different environmental conditions, and ensure the safety and economic operation of air cooling unit. In this paper, the air cooling system in power plant is introduced in detail. Through the analysis of the condenser heat transfer model and the calculation of exhaust steam pressure, the influence of exhaust steam heat load, air temperature at the inlet of air cooling unit and the wind speed on the condenser pressure is studied. The operating characteristics of the air-cooled condenser are obtained, and the operation characteristics of the air-cooled condenser are discussed. Taking a 660MW direct air-cooled unit as an example, the influence of different operation modes of the fan on the condenser pressure is calculated and analyzed. The optimum operation test of an air cooling island for a 660 MW supercritical direct air cooling unit was carried out. By changing the frequency of air cooler under different unit load and ambient temperature, the exhaust steam pressure, unit output, air cooling island power consumption and unit net power are obtained under different operating modes of fan. Through comparison and analysis, the optimal operation mode of fan and the optimal control back pressure of unit under different operating conditions are obtained, which can provide a reference for the economic operation and regulation of fan group of direct air-cooled unit under different environmental parameters and loads.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621

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