为了揭示两机一塔布局下空冷塔流动换热特性对两发电机组运行热经济性的影响，本文通过建立空冷塔三维数值计算模型和机组热力系统一维仿真模型并进行耦合求解，在两机一塔布局下，研究了变环境风速、两机变负荷工况运行下空冷塔的流动换热特性及其与机组运行热经济性的关联关系，结果表明：两机非均等负荷搭配运行会导致空冷塔各方位散热器进气温度冷热不均，削弱静风下空冷塔的通风与散热，但会改善中高风速下塔侧散热器性能并减缓环境风对空冷塔散热的不利影响，且机组负荷越高，机组背压对环境风速的变化就越敏感。在全厂热经济性方面，两机均等负荷搭配运行下两机的总负荷越高，全厂热经济性越优，且整体加权标准煤耗率明显低于相同总负荷下两机非均等负荷搭配运行。

In order to reveal the influence of the flow and heat transfer characteristics of the dry cooling tower on the thermal economy of the two generating units under the configuration of two units sharing one tower, a three-dimensional numerical simulation model of dry cooling tower and an one-dimensional thermodynamic cycle model of power generating unit were developed and coupled in this paper. For the configuration of two power units sharing one dry cooling tower, fluid flow and heat transfer characteristics of the integrated dry cooling tower and their correlation with thermal economy of the two power units were investigated under different crosswind speeds and unit loads. The results showed that the uneven load combination of the two units leads to uneven air inlet temperature distribution of the radiators located at various directions of the integrated dry cooling tower, which diminishes the ventilation and heat dissipation rates of the tower under windless condition. But the uneven air inlet temperature distribution improves air intake and heat transfer of the sideward radiators at the medium-high wind speeds, and thereby mitigates the adverse effect of ambient crosswind on cooling performance. The higher the unit load, the more sensitive the back pressure is to the change of ambient wind speed. In terms of thermal economy of the whole plant, the higher total load under the combined operation of two power units with equal load will bring the better thermal economy to the whole plant, and its overall-weighted standard coal consumption rate is obviously lower than the combined operation of uneven load under the same total load.

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国家自然科学基金项目（No.51976031，No.52206007）