为提高火电机组的热经济性,令凝汽器在最佳真空下运行,通过对某1000MW机组进行汽轮机微增出力试验和循环水泵耗功试验,得到机组微增出力和背压的拟合公式及循环水泵耗功和变频泵频率的拟合公式,并建立循环水泵优化运行的数学模型,经过分析可知循环水泵共有五种运行趋势,利用该机组某段时间的运行数据,模拟了三种典型情况下的循环水泵的运行变化。模拟试验结果表明：增大变频泵频率,机组净收益功率为正,继续增大频率,机组净收益功率不断增大,直至变频泵频率达到50Hz；增大变频泵频率,机组净输出功率为负,减小频率,机组净收益功率为正,继续减小频率,机组净收益功率不断增大,在频率减小至44Hz时,机组净收益功率达到最大值；增大或减小变频泵频率,机组净收益功率均为负,此时原变频泵运行频率即为最佳运行频率,利用该数学模型能够有效寻找变频泵最佳运行频率,实现机组的优化运行。

In order to improve the thermal economy of the thermal power unit and make the condenser run under the optimal vacuum, the fitting formulas of the unit"s slightly increased output and back pressure, the fitting formulas of the circulating pump"s power consumption and the frequency of the variable frequency pump were obtained through the steam turbine"s slightly increased output test and the circulating pump"s power consumption test on a 1000MW unit, and the mathematical model of optimal operation of the circulating pump was established. According to the analysis, there are five operating trends of the circulating water pump. Through analysis, we can see that there are five operating trends of circulating pumps. Using the operating data of the unit for a certain period of time, the operating changes of circulating pumps under three typical circumstances are simulated. The simulation test results show that the net income power of the unit is positive when the frequency of the inverter pump is increased, and the net income power of the unit is increased continuously when the frequency of the inverter pump is increased until the frequency of the inverter pump reaches 50Hz. When the frequency of the frequency conversion pump is increased, the net output power of the unit is negative; when the frequency is reduced, the net income power of the unit is positive; when the frequency is reduced to 44Hz, the net income power of the unit is increased continuously; When the frequency of variable frequency pump is increased or decreased, the net income power of the unit is negative, and the operating frequency of the original variable frequency pump is the best operating frequency. The mathematical model can be used to effectively find the best operating frequency of the variable frequency pump and realize the optimal operation of the unit.

TK26

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