Research and Development of Condensate Water Fined Processing Control System Based on FCS

Transcription

1 Journal of Energy and Power Engineering 9 (2015) doi: / / D DAVID PUBLISHING Reearch and Development of Condenate Water Fined Proceing Control Sytem Baed on FCS Cheng Bei Department of Automation, Anhui Electrical Engineering Profeional Technique College, Hefei , China Received: February 13, 2015 / Accepted: April 08, 2015 / Publihed: July 31, Abtract: Thi paper briefly tate the feature and advantage of FCS (fieldbu control ytem). In view of condenate water fined proceing ytem of dometic 600 MW upercritical coal-fired generating unit, it deigned and developed a FCS for entirely proce control, deigned computer monitoring oftware and organized network monitor the change of data. At the ame time, making the imulation device of the ytem, the FCS control ytem cheme i implemented on thi device. It i verified by practice that the ytem control technology i advanced, afe, reliable and operation well. It provide a complete project for automation technology upgrade program in power plant. In addition, thi device can be ued in the power indutry technical peronnel training and teaching of college and univeritie. It i worth promotion and reference. Key word: FCS, equential function chart, programmable control, monitoring. 1. Introduction Proce control ytem ha gone through four generation: the bae meter control ytem, electric unit combined analog control ytem, centralized control ytem and DCS (ditributed control ytem). With the development of indutrial intelligent device, a well a the development of digital communication, the field bu technology gradually formed at the end of nineteen eightie in the world. A new ditributed control ytem which take the technology a the core FCS (fieldbu control ytem) i known a the fifth generation control ytem. The ytem connected all the ite meter, controller and other intelligent to the ame bu. It i a real-time network control ytem which ue open field bu control communication network, production ite controller and intelligent intrument equipment at the automation bottom being interconnected [1]. The FCS ytem i far le mature than the DCS ytem when it entered into China. So far, FCS ytem i till motly ued in medium or Correponding author: Cheng Bei, profeor, reearch field: proce automation. chengbei_68@126.com. mall engineering project. FCS tructure hould adopt the ue of Fieldbu Technology in the field equipment layer, all the equipment control trategie in control ytem [2]. The field bu technology i alo gradually integrated into the power indutry. Along with the application of Fieldbu Technology in low voltage electrical apparatu, high voltage witchgear, low-voltage complete et of equipment, it effect i more and more prominent. It i the key to realize the automation of electric power ytem. At preent, there have been more mature fieldbu product and ytem ued in power plant, ubtation automation, ditribution automation, gained very high economic benefit and development propect. In the thermal power unit, more and more, the field bu control ytem i ued in pneumatic or electric control valve of non important regulating loop, witch type electric valve, 380 V and 6 kv motor, and factory electricity power ytem, the field bu control ytem i alo ued in water treatment ytem, ah and lag removal ytem, electricity dut removal ytem, deulfurization ytem and coal conveying ytem [3].

2 674 Reearch and Development of Condenate Water Fined Proceing Control Sytem Baed on FCS 2. Condenate Water Fined Proceing Control Device The condenate water fined proceing imulation control training device belong to the contruction project of national key vocational college approved by Minitry of Education, and belong to project to improve the profeional ervice indutry development capability upported by the central financial [4]. The training device take the condenate water fined proceing ytem of homemade 600 MW upercritical coal-fired generating unit a the reearch object. The ytem phyical model i etablihed, and full automatic control ytem i realized. Condenate fined proceing ytem i arranged in thermal power plant of large capacity, high parameter. A condenate water i ultimately ent to the pipeline of power plant boiler heating urface, the water quality will directly affect the quality of the feedwater. In order to enure afe and economic operation of the unit, to prevent the corroion and fouling of heating urface and turbine, it i neceary to carry on the fine treatment of condenate, remove the metal corroion product and impuritie carried due to condener leakage [5]. The training device deigned conit of one pre-filter and two 100% high-peed mixed bed. Filter and the mixed bed are arranged in erie. Currently, in the dometic upercritical, ultra-upercritical unit, all prefilter are tube type with filter element. During normal operation, condenate water pae through the condenate pump into the fine proceing ytem. Firtly, iron, copper and other metal in the thermal ytem, the reidual welding lag in pipe, ediment and other mechanical impuritie, and upended matter, are removed by the filter effect. In addition, the rein operation period and ervice life i prolonged becaue of the larger ize particle removal. In the mixed bed, trong acid cation rein and trong alkali anion rein form the mixed rein layer. The rein are all homogeneou particle gel type. The main role i to remove diolved alt of condenate water (i.e., the variou anion, cationic), alo to remove the upended olid and colloidal impuritie leaking out from the filter. Now, the condenate water conductivity i generally le than 0.2 m/cm. Therefore, through the filtering and removal of alt function, the fine proceing of condenate i achieved. Prefilter ytem i provided with a 100% bypa. When the prefilter preure drop expand over a certain value, it tate that a large number of olid are intercepted. Then the prefilter quit out of operation, the condenate bypa paage. Filter will be backwahed by backwahing water. Two mixed bed, one running, one backup, when the running bed i not qualified or preure difference i too large, it will launch another mixed bed and recycling operation until the effluent i up to tandard and pae into the ytem. At thi time, the looe effectivene mixed bed plit. Mixed bed ytem equipped with a 100% automatic bypa. When the condenate water temperature over 55 C or ytem preure difference i greater than a certain value, the bypa valve will automatically open, the input and output water pipe valve of the mixed bed ytem will cloe. The fine treatment ytem et up a 100% bypa and iolation valve, automatic bypa valve equipped with a manual bypa valve for repairing. Deign of three level bypa ytem enhance the ytem operation flexibility, and i convenient for equipment failure treatment. 3. Control Sytem Contruction 3.1 Control Sytem Structure The condenate water fined proceing control ytem tructure i of the FCS claification control ytem baed on profibu-dp (decentralized periphery) bu. PLC (programmable logic controller), DP remote IO (input/output) digital module and DP/PA (proce automation) coupler are hanging in the bu. In addition,

3 Reearch and Development of Condenate Water Fined Proceing Control Sytem Baed on FCS 675 another et of PC (peronal computer) i et up. 5,611 communication card and PLC configuration oftware STEP7 V5.4 and fieldbu intrument configuration oftware PDM (product data management) 6 are intalled in the PC. The PC machine alo communicate with Siemen PROFIBUS PA bu intrument and PLC through the bu. Sytem parameter ignal are ent to the remote monitoring tation through the optical fiber. The remote control center i the upper layer, operator and engineer tation are et [6]. Due to the optical fiber communication i of high reliability and high ecurity, trong anti-interference ability, wide bandwidth and long tranmiion ditance and o on, thi ytem make up a ring network by uing optical fiber module, indutrial Ethernet witch EKI7659C and fiber. The production ite and remote monitoring center are linked, completing production equipment monitoring, control and operation management (Fig. 1). Sytem control cabinet adopt a tandard indutrial control cabinet, with a big power fan on the top, a lower waterproof air inlet groove, and high trength tranparent gla in front. One can watch the entire cabinet intrument operation without opening the cae. The whole cabinet body i of platic coating tructure, protecting againt electric hock. In addition, the grounding device i et. In the control cabinet, variety of tandard part and control intrument module are fixed in the front panel. The three-phae line four (~380 V, ~220 V) ingle-phae power i upplied for, controlled by the four phae three wire air witch. Leakage protection air witch i et, the afety compliance with international tandard. Internet Profibu-DP bu net firewall Enterprie MIS ytem router E t h e Optical fiber high peed redundancy ring network E T S IM151-1 PM-E 4DI 4DI 2AI Field I/O equipment Engineer tation r 2AI Operator tation n e PLC S DP Operator tation t DP/PA coupler PA bu field gage Operator tation CP5611 PC MIS management information ytem; PM power module; DI digital input; DO digital output; AI analog input; CP communication proceor. Fig. 1 Control ytem tructure diagram.

4 676 Reearch and Development of Condenate Water Fined Proceing Control Sytem Baed on FCS 3.2 Control Strategy In conideration of water treatment ytem i a typical equence control ytem, thi control trategy implementation method i to determine the tatu of each equipment and operation equence and hift condition, draw the SFC (equential function chart) and programming. The SFC programming language make the program tructure clear, eay to read and maintain, greatly reduce the programming workload, and horten the programming and debugging time. The ytem main SFC i hown in Fig Program Organization Then ued PLC configuration oftware STEP7 V5.4 to program, program block i a hown in Table 1 [6]. The OB (organization block)1 block, i the main program proceing uer communication, and realize the input and output. But the cycle i not fixed, and the priority i relatively lower. But the communication proceing configuration monitoring i very timely, o it i called FC (function)5 block, avoiding the contradiction problem that the monitoring center require the input of ytem, while the FC5 block aking to withdraw [7]. S0 Start condition i atified S1 Open exhaut valve Water flow out of exhaut valve S2 Cloe exhaut valve Programmed tart command S3 Open outlet and inlet valve of filter Filter effluent unqualified Filter effluent qualified Start the filter fault handler program S4 S5 D Open outlet and inlet valve of elected mixed bed Delay 2 min Conductivity qualified Conductivity unqualified Cloe bypa valve S6 S7 Start interlocking ubroutine = 1 End of program tart Fig. 2 Main SFC of equence tart.

5 Reearch and Development of Condenate Water Fined Proceing Control Sytem Baed on FCS 677 Table 1 Program block lit. Block Function Decription OB1 Execution a oon a poible The main program call FC5 FC1 Overall operation Monitoring filter, mixed A, B tate FC2 Pre filter operation Including the initialization, plitting and backwah FC3 Mixed-bed A operation Including the initialization, plitting and backwah FC4 Mixed-bed B operation Including the initialization, plitting and backwah FC5 Sytem operation judgment Determine the ytem input allowable condition Fig. 3 Real-time monitoring creen. The I/O analog module need quantity converion, uing the SCALE function provided by FC105 ytem. 4. Monitoring Screen Configuration Kingview oftware i of global indutry uperviory control. It i uitable for production and operation management and fault diagnoi of ingle equipment, and development of large centralized monitoring and management ytem. Thi ytem produced monitor creen with Kingview oftware. OPC (object linking and embedding for proce control) connection i etablihed between the Kingview oftware and the intrument [8]. The uperviory creen i hown in Fig Concluion Condenate fined proceing control imulation training device i a new practical device independent

6 678 Reearch and Development of Condenate Water Fined Proceing Control Sytem Baed on FCS reearch and development. It can not only be ued in variou chool and univeritie for automation coure teaching and training, but alo provide a detailed and comprehenive cheme for power plant to upgrade automation technology and level. The device ha been put into the teaching operation, and ha good effect, worthy of promotion. Reference [1] Bo, R., and Li, Q Fieldbu Technology and It Application. Beijing: Aviation Indutry Pre. [2] Bei, C., and De-xing, Z Reearch and Development of Solar Wind Heater Field-Bu Control Sytem Baed on FF Intrument. China Intrumentation 33 (1): [3] Zu-hui, Q., Xiao-li, W., and Xuan, L Fieldbu Application in Programmed Large Scale Heat Power Plant Sytem. Indutrial Control Computer 22 (5): [4] Bei, C., Xin, L., and Cheng-jin, C Reearch and Development of Condenate Water Fined Proceing Sytem Modulating Control Practical Equipment. Electrical Automation 34 (1): [5] Rui, X., and Ji-hong, T Comparion of the Different Type Mixed Bed of Condenate Treatment Operation. Jiangxi Electric Power 24 (2): [6] Shuang, T., Wei, H., and Mei-yan, S FF and Profibu Field-Bu Technology Baed Water Net Control Sytem for Laizhou Power Plant of China Huadian Corporation. Thermal Power Generation 42 (1): [7] Hong-yi, F., and Jun, S Application and Dicuion of PLC in Bag Filter Control Sytem. Natural Science Journal of Harbin Normal Univerity 25 (3): [8] Li-e, S., Yi-feng, W., and Li-ping, Z Study on Wet Flue Ga Deulpherization Aborber Monitoring Sytem Baed on PLC and FCS. Journal of Fuzhou Univerity 39 (1):