Abstract

The results of the comprehensive investigation into operation of a dry mechanical draft cooling tower (DMDCT) of a PGU-220 power unit at the TETs-12 cogeneration power station of PAO Mosenergo are presented. Thermal performance of the main and auxiliary DMDCTs and their individual sections is examined. To determine the cooling-air flowrate, a rake consisting of 11 velocity transducers and thermocouples was installed at the fan outlet above the fan diffuser of the examined section. The DMDCT heat balances calculated on the basis of water- and cooling-air conditions agree with each other with a maximum error of 8%. The overall thermal performance indices of the main and auxiliary DMDCTs were lower than those specified by the supplier. Performance of DMDCT fans was investigated at different blade angles α. According to our calculations, the effect of better fan performance in terms of an increase in the power of a steam turbine in a combined-cycle unit at α > 15° does not compensate for an increase in the power consumption of fan motors and even reduces the amount of delivered power. Therefore, the range of α = 10°–15° for the fans of the main DMDCT may be considered optimal. As to the auxiliary cooling tower, an increase in the air flow at α = 17° can offer a wider operation range for the fans at high ambient air temperatures, which is important considering limitations on the supply temperature (below 35°С) of the auxiliary equipment cooling water. The investigation of DMDCT operation during the cold season yielded the dependence of the minimum heat load of DMDCT, required for its safe operation, on the ambient air temperature. The study into the performance of the humidification system revealed that its efficiency is inadequate. The best solution to this problem is to replace the normal humidification nozzles with nozzles with smaller diameter holes to improve water dispersion that will prevent the water drops from falling onto the ground and improve the efficiency of the humidification system while decreasing the water flow to the humidification nozzles.

中文翻译：

---

PAO Mosenergo TETs-12热电联产电站干式机械通风冷却塔的运行条件研究

摘要

提出了对PAO-Mosenergo的TETs-12热电联产电厂的PGU-220动力装置的干式机械通风冷却塔（DMDCT）进行全面研究的结果。检查了主DMDCT和辅助DMDCT及其各个部分的热性能。为了确定冷却空气的流量，在所检查部分的风扇扩散器上方的风扇出口处安装了由11个速度传感器和热电偶组成的耙子。根据水和冷却空气条件计算出的DMDCT热平衡彼此一致，最大误差为8％。主DMDCT和辅助DMDCT的总体热性能指标低于供应商指定的指标。研究了DMDCT风扇在不同叶片角α下的性能。根据我们的计算，就联合循环单元中的蒸汽涡轮机的功率而言，在α> 15°时，风扇性能的改善效果无法补偿风扇电机的功耗增加，甚至减少了输出功率。因此，对于主DMDCT风扇，α= 10°–15°的范围可能被认为是最佳范围。对于辅助冷却塔，在较高的环境空气温度下，α= 17°时的空气流量增加可以为风扇提供更宽的运行范围，考虑到对空调的供应温度（低于35°С）的限制，这一点很重要。辅助设备冷却水。对DMDCT在寒冷季节的运行情况的调查得出了DMDCT安全运行所需的最小热负荷对周围空气温度的依赖性。对加湿系统性能的研究表明，其效率不足。解决此问题的最佳方法是用直径较小的喷嘴替换普通的加湿喷嘴，以改善水分散性，从而防止水滴落到地面上，并提高加湿系统的效率，同时减少流向加湿器的水量喷嘴。