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毕业设计

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dq030智能恒压供水系统设计,毕业设计

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信息与电子工程系 毕业设计（翻译） - 1 - 外文 资料 (英文 ) The matter of water supplying is in relation to the national economy and the peoples livelihood, and it is much accounted by the countries all over the world. In the water supplying system, water pump use a lot of energy, so the electronic consumption usually takes 60% in the whole cost of the water refinement. Every year, the electronic consumption of the water pump takes more than 21% in the whole electronic consumption in our country. If we use the frequency conversion timing technology to rebuild the application of water pump technically, 20-50% electronic energy can be saved, and thousands upon thousands of electronic energy can be saved every year in the country. The effect of saving electricity is very significant. According to the practical application circumstance of the water factory, this article analyzes the applying method and project of FUZZY-PID control and second PID setting value in the constant pressure water supplying system and compares the result before and after the application. The present application indicates that the system applies reliably, has great stability, the effect of the energy saving remarkable, operation convenient, intendance timely, and the starting ability improved a lot. In the water supplying system of one water factory, a water pump fit out with a 132kw frequency conversion timing equipment and the other 110kw are required to meet the demand of the water user by cutting of the water pump duly and adjusting the rotate speed in order to keep the pressure constant. In the real application, because the use s top water line is 50 meters higher than the one in the factory, during the progress of the water supplying, if the water pump rotates too slowly, the water will flow backwards. Therefore, the requirement of the control system should be very strict: response speed fast, accelerate time short, no over-control and lack of control phenomenon, and the static balance slim. The constant pressure water supplying system composed of FUZZY-PID controller, PLC, inverter, pressure transducer and electronic control system. The composing of the system is as the picture 1 shows: The controller is the Japanese rational FUZZY-PID controller, which is a technically advanced instrument with a high control quality, without over-control and lack of control phenomenon and with illegible function. PLC uses Fuji PLC to control the application logic of the too pumps and change the parameter of the controller. The system changes the speed of the pump according to the changes of water quantity to carry out the constant pressure water supplying. nts 信息与电子工程系 毕业设计（翻译） - 2 - The application of the system is controlled by the PLC. The PLC sends signals to start the pump No.1, and opens the valve when the pressure approaches the fixed amount and the application frequency approaches stability. When the transducer works in the full frequency, the pressure cannot reach the fixed amount, the pump No.2 should be operated. When the pressure overruns the fixed amount, the transducer still working in a low frequency, there is no pump to reduce. PLC then sends warning signals, and two pumps working together, so the pressure overruns the fixed amount and the transducer works in a low frequency, then the No.2 pump should be cut off. When the transducer works in a full frequency, but the pressure still cannot reach the fixed amount, there is no pump to add. The PLC sends warning signal In order to avoid the surge, the system uses delay filtration method. Besides, the system has a control function of frequency, electricity and pressure. It also can send warn signals when the pressure is unusual and the transducer is broken. According to the hydrodynamics, the relation among the pressure P, the flow quantity Q and the power N is like this: N=PQ (1) However, the relation between the power and the cube of the speed of the pump directs ratio. In the picture No.2, Q= gHK 2 (2) the curve stands for the different point in the special curve of P=F(Q). The whole constant pressure water supplying system is technically controlled by an advanced frequency conversion timing technology. Aim at the special character of the water factory s supplying, we point out the function of the second PID setting value in improving the starting ability. The system applies reliably, has great stability, the effect of the energy saving remarkable, operation convenient, intendance timely, and the starting ability improved a lot. nts 信息与电子工程系 毕业设计（翻译） - 3 - 外文翻译 (中文 ) 供水问题关系到国计民生，日益受到世界各国的普遍重视。在供水系统中，水 泵耗能巨大，电耗往往占制水成本的 60%以上，我国每年水泵的电能消耗占电能总消耗的 21%以上。若采用变频调速技术对水泵运行进行技术改造，可节电20-50%，全国每年可节电几百亿度，其节电效果相当可观。 根据水厂的实际运行情况，深入分析了智能 FUZZY-PID控制以及 PID第二设定值在恒压供水系统中的应用方法和实施方案，并对运行前后的结果进行了分析和比较。现场运行表明，系统运行可靠、稳定性好、节能效果显著，操作方便，监控及时，并且启动性能得到了有效地改善。 例如 ,某水厂供水系统中，配备了用变频调速装置驱动的 一台 132kW 和一台110kW的水泵，要求通过实时切泵、调节转速使管网压力保持恒定以满足用户用水需求。实际运行中，由于用户用水最高点的水位高出水厂供水点 50 米，在连续供水时如果水泵的转速过慢，造成扬程降低时，会产生水流倒灌现象，这就对对控制系统的性能提出了严格的要求 :响应速度快，加速时间短，基本无超调和欠调现象，系统稳定时静差小。 恒压供水系统由智能 FUZZY-PID 调节器、单片机、变频器、压力传感器和电控系统组成。 系统运行由单片机来控制，单片机发出信号先启动 1号泵，在压力接近设定值，运行频率稳定时，打开 1号泵阀门。当变频器工作在满频，管网压力达不到设定值时，增加 2 号泵 ;当压力超过设定值，变频器仍工作在低频时，表明已无泵可减，单片机发出报警信号。两个泵同时运行时，当压力超过设定值，并且变频器工作在低频时，切除 2号泵 ;当变频器工作在满频，压力仍达不到设定值时，表明已无泵可加，单片机发出报警信号。为了避免加减泵时出现切换振荡现象，系统在加减泵时采用延时滤波的方法。此外系统还具有频率、电流、电压、管网压力等监视功能以及压力异 常报警、变频器故障报警等功能。 由流体力学可知，管网压力 P，流量 Q和功率 N的关系为 : N=PQ (1) 而功率与水泵电机转速 n 的三次方成正比关系。图 2