电机调速技术在火力发电厂中的应用

发布时间：2018-04-14 20:55

本文选题：火力发电厂 + 厂用电率　；参考：《郑州大学》2017年硕士论文

【摘要】：随着国家电力体制改革进程的逐步推进,发电企业成为了一个独立的经营主体。随着电网装机容量的不断扩大及煤价的不断上涨,发电企业之间能耗指标的竞争越来越激烈,各发电企业为了争取更多的利润,都在深入地开展节能降耗工作,努力将煤耗指标和发电厂用电率降到最低,来提升自己在市场中的竞争力。发电企业的厂用电率水平直接影响到企业的供电煤耗和上网电量,发电机发出同样的电量,厂用电率越低,上网电量就越多,供电煤耗就越低。本文阐述了主要厂用辅机设备的构成情况,以及电厂中最常见的泵与风机类负载的机械特性。辅机影响厂用电率的因素就是辅机运行效率的高低,由于辅机在设计时留出的裕量较大,再加上调节辅机出力时通过调节挡阀门开度来实现,使得一部分能量消耗在节流损失上,造成了辅机能耗水平高。本文主要通过结合火电厂主要辅机泵与风机的运行调节特性,对发电厂主要辅机电动机特性及所带负载的机械特性进行分析,得出了目前发电厂提高辅机运行效率的最有效的手段就是采用调速调节。本文详细论述了交流电机的各种调速方法,并在技术经济方面进行了对比分析,得出了目前适合火力发电厂辅机的主要调速方式有变频调速、液力偶合器调速以及变极调速三种,这三种调速技术分别适用于不同场合和设备上,在应用中各有优缺点,结合设备的运行调节特性,在不影响安全的前提下,选择适合的调速方式,可以达到很好的节能效果。论文的最后通过对比分析发电厂的凝结水泵、循环水泵的实际改造项目,证实了采用调速改造节能效果明显,辅机自身耗电量降低后,明显降低了发电厂的厂用电率,降低了企业的发电成本,经济效益明显提高。
[Abstract]:With the progress of national electric power system reform, power generation enterprises have become an independent main body.With the continuous expansion of power grid installed capacity and the rising of coal price, the competition of energy consumption index among power generation enterprises is becoming more and more fierce. In order to strive for more profits, all power generation enterprises are carrying out energy saving and consumption reduction work in depth.Efforts to minimize coal consumption targets and power generation rates to improve their competitiveness in the market.The level of the power supply rate directly affects the coal consumption and the power consumption of the power supply company. The same electricity quantity is emitted by the generator. The lower the power consumption rate is, the more the power supply is, and the lower the coal consumption is.This paper describes the composition of main auxiliary equipment used in power plants and the mechanical characteristics of the most common pumps and blower loads in power plants.The factor that affects the auxiliary power consumption rate is the operating efficiency of the auxiliary machine. Since the auxiliary machine has a large margin in the design, and when adjusting the output force of the auxiliary machine, it can be realized by adjusting the opening degree of the stopper valve.A part of energy is consumed on throttling loss, which results in high energy consumption level of auxiliary machine.In this paper, the characteristics of the main auxiliary motor and the mechanical characteristics of the load in the power plant are analyzed by combining the operating and regulating characteristics of the main auxiliary pump and fan in the thermal power plant.It is concluded that the most effective way to improve the efficiency of auxiliary machines in power plants is to adopt speed regulation.In this paper, various speed regulation methods of AC motor are discussed in detail, and the technical and economic aspects are compared and analyzed. It is concluded that the main speed regulation methods suitable for auxiliary machines in thermal power plants are frequency conversion speed regulation at present.There are three kinds of hydraulic coupler speed regulation and variable pole speed regulation. These three speed regulation technologies are suitable for different occasions and equipments respectively. In the application, they have their own advantages and disadvantages, combined with the operating and regulating characteristics of the equipment, without affecting the safety.Choose the suitable speed regulation way, can achieve the very good energy-saving effect.Finally, by comparing and analyzing the actual retrofit projects of condensate water pump and circulating pump in power plant, it is proved that the energy saving effect of speed regulation reform is obvious, the power consumption of auxiliary machine itself is reduced, and the power consumption rate of power plant is obviously reduced.The cost of power generation has been reduced, and the economic benefits have been significantly improved.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM621

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