基于环境风影响的空冷机组排汽压力优化研究

摘要

Environmental wind has obvious influences on the economic operation of direct air -cooled unit,so it is important to determine the optimal exhaust pressure of the unit considering the effects of environmental wind for achieving energy saving.Take a certain NZK600-24.2/566/566 unit as an example,in order to keep unit operating under optimal exhaust pressure,the objective function of optimal exhaust pressure was built up , and the optimal fan speed was obtained by calculating the fan’ s actual working point .The results show that both the optimal speed of the fan and exhaust pressure increase with rising unit load or ambient temperature or wind speed , the influence of ambient temperature on the exhaust pressure becomes greater when the temperature gets above 20℃, and part of the fans need to be shut down under certain loads if the temperature falls below -10℃; What’ s more, the wind direction also has effects on the optimal exhaust pressure, the optimal speed of the fan under prevailing wind direction is lower than that of other directions .Thus, the optimization of cold end system provide helpful guidance for the economical running of direct air -cooled units .%环境风对直接空冷机组的经济运行具有较大影响，基于该因素确定机组最佳排汽压力，对实现节能降耗具有较大意义。以NZK600-24．2/566/566机组为例，建立最佳排汽压力目标函数，通过确定风机实际工作点，计算最佳风机转速，以保证机组在最佳排汽压力下运行。计算结果表明：随着机组负荷、环境温度或风速的增加，最佳风机转速和排汽压力也随之升高，反之降低；温度高于20℃，其对排汽压力的影响较为突出；温度低于-10℃，在某些负荷下要停运部分风机；同时，环境风向对机组也具有一定影响，主导风向下最佳风机转速低于其它风向。通过对冷端系统进行优化，为机组的经济运行提供指导。