【作者】 刘宁；

【导师】 叶学民；

【作者基本信息】 华北电力大学 ， 动力工程， 2011， 硕士

【摘要】 目前,面对“厂网分开,竞价上网”的电力市场形势以及煤电价格不能联动的严峻局面,降低发电成本成为电力企业的“求生存,促发展”的立足之本。凝结水泵作为电厂的重要辅机,由于长期采用定速运行、通过节流控制流量的运行方式,致使其运行经济性较差,因此,通过对凝结水泵进行变频改造从而降低辅机厂用电率,就成为摆在电力企业面前的一种有效途径。本文在总结和分析国内多家电厂凝结水泵变频改造案例的基础上,确定了采用高压变频“一拖二”的凝结水泵改造方案,根据负荷范围、运行可靠性及匹配性因素确定了变频器参数。针对变频改造后存在的问题,对变频控制系统中的故障报警条件和逻辑控制等多方面进行了设定和修改,对技术改造中的难点进行了优化设置或修改,保证了系统的安全稳定运行。经济性分析表明,与改造前相比,采用变频调节后的节能率为49.59%,变频后的凝结水泵运行稳定、可靠,节能效果非常显著。更多还原

【Abstract】 Currently,the serious situation, including power plants separating from power grids and electricity price not keeping pace with coal price, is great changllege for every power plants. So, decreasing generating cost has become the essential ability of power enterprise for making longer survivorship and accelerating development. As one of most important auxiliaries in power plants, coagulate pump is in state of long-term operation with constant speed, the throttling control mode leads poor economical efficiency. As a result, in order to decreasing the power-consumpted ratio of auxiliaries, frequency conversion retrofit coagulate pump has become an efficient mean for power enterprises.On the basis of summarizing and analyzing frequency conversion alteration cases of coagulate pump in domestic power plants, the retrofit scheme of“one driving two”with high voltage frequency conversion techonolgy is determined. Frequency converter parameters are specified by load range, operational reliability and matching ability. For the existing prolems after retrofit, many aspects including failure alarm conditions and logic control in frequency conversion control system are setted or modified, and the key points of technical innovation are optimized or updated, which guaranting safe and stable operation. Economic analysis shows that by comparison with energy consumption before alteration, energy saving ratio is 49.59% with frequency conversion alteration, and the retrofitted coagulate pump operates stably and reliably with a remarkable energy-saving effect.更多还原