火力发电干湿联合冷却系统性能实验研究

火力发电干湿联合冷却兼具湿冷散热能力大和空冷节水的优势,同时,还可依据机组负荷条件和电厂的环境气象条件变化,调节不同的冷却方式,使机组具有更好的灵活性和环境适应性。为掌握火力发电干湿联合冷却性能,在干冷段和湿冷段并联和串联运行2种模式下,建立联合冷却系统实验台;开展不同运行条件下,联合冷却系统干冷段和湿冷段热负荷分配的实验研究,以及不同运行模式下耗水量与冷却能力的变化规律;采用单变量分析法,研究环境温度、环境湿度等因素对联合循环系统性能的影响。结果表明,环境湿度升高后,系统不同运行模式受到循环水蒸发速率下降的影响,散热量、耗水量有所降低;得到环境温度升高所导致的散热量随系统换热温差减小的定量结果;揭示出耗水量随着湿冷段和干冷段热负荷分配比例的变化规律。研究结果为不同气象条件下,干湿联合冷却系统运行模式和热负荷分配比例的优化提供了实验基础。

Experimental Study on Performance of Hybrid Cooling System for Thermal Power Generation

Hybrid cooling systems of thermal power generation have the advantages of large wet-cooling capacity and air-cooled water saving. It can also adjust different cooling methods according to the load conditions of the unit and the environmental meteorological conditions of the power plant, so that the unit has better flexibility and environment adaptability. In order to master the hybrid cooling performance of thermal power generation, a combined cycle cooling system test bench was established in parallel and series operation modes of dry and wet-cooling sections. The experimental research on the heat load distribution of the dry-cooling section and the wet-cooling section in hybrid cooling system under different operation conditions was carried out. Changes law of water consumption and cooling capacity under different operation modes was determined. Univariate analysis method was used to study the influence of environmental temperature, environmental humidity and other factors on the performance of hybrid cooling systems. The results show that after the ambient humidity increases, the different operating modes of the system are affected by the decrease of the circulating water evaporation rate, and the heat dissipation and water consumption are reduced. What is more, quantitative results are obtained with the increase of ambient temperature and the decrease of the heat transfer temperature difference, revealing the changes law of water consumption with the proportion of heat load distribution in dry and wet-cooling sections. The research results provide an experimental basis for optimizing the operation mode and heat load distribution ratio of hybrid cooling system under different meteorological conditions.