转速对AP1000核主泵水力性能影响的试验研究

The Experimental Study on the Influence of Rotating Speed on the Hydraulic Properties of AP1000 Nuclear Main Pump

为研究转速对AP1000核主泵水力性能的影响,制造一台核主泵水力模型样机,通过变频改变转速,进行了试验研究,分别对比了核主泵在50Hz(1495r/min)、40Hz(1195r/min)、30Hz(895r/min)3种不同转速下的Q-H、Q-P、Q-η曲线,运用相似比例定律,变换得到相似变换曲线,对比试验和相似变换曲线,得到结果如下:50Hz时该水力样机的过流部件满足设计要求,其性能曲线具有混流泵的特点,有无过载特性,高效区较宽,大流量时具有较高的效率;压水室截面形状对核主泵水力样机性能变化趋势影响有限,决定其性能的主要因素在于叶轮;转速改变时外特性曲线变化趋势相同,但转速降低,扬程下降缓慢,Q-H曲线相对平坦,最大轴功率点向大流量偏移,泵的总体效率下降,最高效率降低,同时高效区变窄。转速降低超过20%相似比例变换公式失效,引入了修正系数对相似变化曲线进行修正。

In order to study the effect, rotational speed on the hydraulic properties of AP1000 nuclear main pump, to build a nuclear main pump hydraulic model prototype, an experimental study is conducted by changing rotation speed through frequency. It respectively compared the Q-H,Q-P,Q-η curve under three different rotational speed of the nuclear main pump in 50Hz（1495r/min）, 40Hz（1195r/min）, 30Hz（895r/min）. Transformation curves are transformed by using similarity scaling law. By comparing the test and similarity scaling transformation curves, the results are as follows： in 50Hz, the flow passage components of the hydraulic prototype meet the design requirements. Its performance curve has the characteristics of mixed flow pump, and non-overload characteristics. The high efficiency area is broad and the effwiency is high when the flow is big. The cross-section of shape pressurized-water chamber limited the effect on the change of the performance of nuclear main pump hydraulic prototype. The main factor is the impeller. When rotational speed changes, the external characteristic curves changes equally. However, when reducing the speed, the head drops slowly and Q-H curve is relatively flat. The maximum shaft power point shifts towards the big flow. The overall efficiency of the pump drops, meanwhile, the highest efficiency reduces and high efficiency area narrows. While, when rotation speed reduces more than 20%, similar scaling transformation formula fails. A s for this, correction coefficient is introduced to modify transformation curves.