Application of Frequency Conversion Technology in Long Distance Pipeline Oil Pump Unit Liu Guohao 1 Yang Lei 1 Zhang Shuai 2 Yang Xiaoming 3 Gu Yingcui 1 Zhang Xin 1 Li Rui 1 1. China Petroleum Corporation Key Laboratory of Oil and Gas Storage and Transportation China Petroleum Pipeline Technology Research Center, Langfang, Hebei 065000; 2. Xi'an Changqing Technology Engineering Co., Ltd., Xi'an, Shaanxi 710000: 3. China Petroleum Pipeline Company Qinhuangdao Oil and Gas Branch, Qinhuangdao 066000, Hebei Liu Guohao, etc. The application of frequency conversion technology in oil pump unit of long-distance pipeline. Oil and gas storage and transportation, 2012, 1 life. In response to this problem, the method of energy-saving control of the pump unit using frequency conversion and speed regulation is proposed. Energy-saving principle of oil pump: keep the flow rate of centrifugal pump unchanged, reduce the lift of centrifugal pump. Taking an actual running long-distance pipeline as an example, the energy-saving test process of the high-voltage frequency conversion project on the long-distance pipeline oil pump unit was introduced in detail, and the energy-saving effect of the oil pump unit before and after the installation of frequency conversion device was compared and analyzed. The results show that after installing the frequency conversion device, the throttle rate, power factor and unit efficiency all meet the requirements of the evaluation standard SY / T6275-2007 limit value and energy-saving evaluation value, and the pipeline saves electricity costs by 304.5X104 yuan in 20082009.
In the long-distance pipeline system, asynchronous motors provide power for oil pumps (mostly centrifugal pumps) and are one of the main energy-consuming equipment for pipeline operation. The annual running time of each oil pump often exceeds 6000h. Therefore, the power consumption of the motor directly affects the running cost of the pipeline. While ensuring the completion of the oil transportation task, reducing the power consumption of the motor is an important task of energy saving and emission reduction for oil transportation companies.
At present, most of the motors of long-distance pipeline systems in China are power frequency fixed speed motors. If the delivery flow reaches the designed output, the power frequency fixed speed motors have obvious advantages. Not only is the structure simple, reliable, durable, but also the work efficiency is high . In recent years, low-throughput operation of pipelines has become more and more common, and the phenomenon of "large horse-drawn carts" appears on power-frequency fixed-speed motors. The oil pump does a lot of useless work through the outlet throttle valve, which wastes electrical energy and shortens the oil pump unit's Maintenance cycle and service life. Therefore, energy-saving transformation is required for asynchronous fixed-speed motors. There are many transformation methods for fixed-speed motors, such as cutting the oil pump impeller, dismantling the oil pump impeller, and installing frequency conversion speed regulation devices. Among them, the cutting impeller is non-recoverable, the oil pump disassembly stage speed regulation range is narrow, and the frequency conversion speed regulation device has a wide speed range, good recoverability, and little mechanical damage to the oil pump unit, so it is widely used.
1 Energy-saving principle According to the 0-W (flow-head) characteristics of the centrifugal pump, the working condition adjustment is mainly to adjust the flow rate. There are two most commonly used methods: adjusting the opening of the pump outlet valve and changing the speed of the centrifugal pump. The operation of adjusting the opening of the pump outlet valve is relatively simple, but the energy waste is more serious; changing the speed of the centrifugal pump changes the motor speed by changing the motor frequency of the centrifugal pump, which reduces the power consumption of the motor and also reduces the pump head and the pump. The throttling loss of the outlet valve, so as to achieve energy-saving control of the operating conditions of the oil pump and meet the requirements of the existing process operating conditions.
Assuming that the same centrifugal pump in the long-distance pipeline system transports the same fluid, when the speed n changes, the performance parameters also change, and its change rule is: from the above formula, when the pump speed changes slightly, the shaft of the pump The power will change significantly. Therefore, when the amount of oil coming in is small, the frequency of the variable frequency motor can be reduced, so that the output power of the motor and the head of the pump can meet the needs of the pump. The principle of centrifugal pump frequency conversion energy saving: keep the flow rate of the centrifugal pump unchanged, reduce the pump head from W to Yi, and save energy by reducing the head of the centrifugal pump.
2 Renovation plan An additional frequency conversion speed control device is added to the main oil pump and a matching inverter room is newly built, and related supporting facilities such as instrument automatic control, fire fighting, heating and ventilation are also transformed accordingly. At the same time, the existing motor was transformed into a voltage source type without harmonic high-voltage frequency conversion speed regulation, and the newly added speed signal of the speed regulation motor was introduced into the station control system of each station. Using the original pressure signals of the in and out stations, the station control system of each station controls the speed of the speed-regulating motor and the opening of the out-of-station regulating valve.
3 Example application Take an actual running pipeline as an example to test the energy-saving effect of the oil transfer pump unit (rated flow rate is 2300m3 / h) after the installation of a high-voltage inverter. The whole pipeline of the oil pipeline is driven by a power frequency fixed speed motor. It adopts the operation mode of sequential delivery of Russian oil and Daqing oil. The average annual output is only 65% ​​of the designed output, and the lower month is only the designed output. 50% of the amount. Due to the pressure limitation of the in and out stations of each station, the throttle valve adjustment causes the waste of power consumption of the oil pump to be extremely serious. At the same time, due to the large difference in viscosity between Russian oil and Daqing oil, during operation, it is necessary to frequently start and stop the oil pump and adjust the pump combination to reduce the friction difference, and the potential operational risk is greater.
3.1 Test method The test instrument has the ability to resist electromagnetic interference, and the power supply voltage is within ± 15% of the rated voltage fluctuation range, the power supply frequency is about 50 (1.0) Hz, the total voltage distortion rate does not exceed 8 %%, and the fundamental wave can be tested and not less than 20th harmonic current, voltage and active power parameters.
Frequency converter and motor test method: Connect to the electrical parameter tester according to the location of the test point where the high-voltage frequency conversion speed control device is installed, test the electrical parameters of the frequency converter input end and output end, and the motor output end, and test their voltage simultaneously With current. The test methods and results of harmonic content and total harmonic distortion rate shall comply with the relevant regulations of harmonics of GB / T1454993 power quality public power grid; the test methods of stator resistance shall comply with the relevant regulations of GB / T1032 2003S phase asynchronous motor test method; motor The test is carried out in accordance with GB / T124972003 three-phase asynchronous motor economic operation4.
Long-distance pipeline oil pump is installed with high-voltage frequency conversion speed control device, and the schematic diagram of the location of the test point and the energy-saving monitoring method of the liquid delivery system 5 and GB / T13468 1993 pump system energy balance test and calculation method are executed.
In addition, the comparison performance test before and after installing the frequency conversion system of the oil pump unit should be increased.
3.2 Test results and evaluation According to SY / T64222008 energy-saving product energy-saving product measurement and SY / T6275 2007 oilfield production system energy-saving monitoring specification requirements, compare the energy-saving effect before and after the installation of frequency conversion device in the oil pump unit (Table 1): installation of frequency conversion Before the installation, the unit efficiency and throttling rate do not meet the limit value requirements in the evaluation standard SY / T62752007 (unit efficiency is not less than 68%, throttling rate is not more than 10%), the throttling rate is too large, and electric energy is wasted; After installing the frequency conversion device, when the output flow throttling rate, power factor and unit efficiency all meet the requirements of the evaluation standard SY / T6275 2007 limit value and energy-saving evaluation value (unit efficiency is not less than 72%, throttle rate is not higher than 10%), belonging to energy-saving operation equipment.
Table 1 Test results before and after the installation of a frequency conversion device for a certain oil pump set. Operating conditions before and after technical transformation. Classification of operating conditions / operation efficiency pump head / m motor power factor pump efficiency unit efficiency throttling rate. 2 Operating condition 1 Operating condition after installing the inverter 2 Operating condition 3 According to the comparative test conditions in SY / T64222008 (flow fluctuation does not exceed ± 5%) and the calculation method, the inverter is put into operation under the operating condition of 1150m3 / h After the active power saving rate, reactive power saving rate and comprehensive power saving rate were 63.53%, 41.73% and 63.15% respectively, the throttling rate dropped from 33.92 °% to 0; The active power saving rate, reactive power saving rate and comprehensive power saving rate after running the inverter are Liu Guohao, etc .: the application of frequency conversion technology in the long-distance pipeline oil pump unit is energy-saving and environmental protection 52.02%, and the throttle rate is reduced from 32.64% to 0 .According to the calculation of the monthly savings data in 2008-2009, the annual actual electricity saving of the pipeline is 382.03X104kW'h. According to the company's average electricity price of 0.797 yuan / kW'h in 2009, the annual electricity cost savings is 104 yuan. After the high-voltage frequency conversion speed regulating device, the economic benefit is remarkable.
In summary, the high-voltage frequency conversion transformation has a good application effect in the field of long-distance pipeline industry, which can greatly reduce the operating costs of oil-transporting enterprises, and at the same time reduce the mechanical shock, wear and noise of oil-transporting pump units, and extend the The maintenance cycle and service life have significant economic benefits.
experiment method. Beijing: China Standard Press, 2006. Xin Dingguo, Zhai Kejun, Zhao Yuejin, etc. GB / T12497-2006 three-phase asynchronous motor economical operation. Beijing National Standard Press, 2006. Yu Zhongmin, Li Weidong, Ning Yingnan, etc. GB / T16666 -1996 Energy-saving monitoring methods for pumps and liquid delivery systems. Beijing: Petroleum Industry Press, 1996. Hu Miaolong, Cheng Jizhong, Li Qiping, etc. GB / T13468-1992 Pump system energy balance test and calculation method. Beijing: National Technical Supervision Bureau, 1992. Zheng Gangrui, Wu Zhaoyun, Liang Shijun, etc. SY / T 6422-2008 Determination of energy-saving effect of energy-saving products of petroleum enterprises. Beijing: Petroleum Industry Press, 2008. Liang Shijun, Sun Degang, Wu Zhaoyun, etc. SY / T6275-2007 Oil field production system energy saving monitoring specification. Beijing: Petroleum Industry Press, 2008. (Received time: 201 Bu 09-19; Editor: Li Zairong)
Wire Egg Basket,Vintage Egg Basket,Metal Egg Basket,Vintage Wire Egg Basket
Hebei Liebang Metal Products Co.,Ltd , https://www.lb-animaltraps.com