Journal of Engineering Science and Technology Review 10 (6) (2017) Research Article. Kai Yang 1,3,* and Yuwei Liu 2

Transcription

1 Jestr Journal of Engneerng Scence and Technology Revew 10 (6) (2017) Research Artcle Optmzaton of Producton Operaton Scheme n the Transportaton Process of Dfferent Proportons of Commngled Crude Ol Ka Yang 1,3,* and Yuwe Lu 2 1 Daqng Olfeld No. 2 Ol Producton Plant, Daqng, Helongjang, , Chna 2 Unversty of Scence and Technology Bejng, Bejng, , Chna 3 Department of Petroleum Engneerng, Curtn Unversty, 6845, Australa JOURNAL OF Engneerng Scence and Technology Revew Receved 12 August 2017; Accepted 21 December 2017 Abstract At present, the mxed transportaton technology of dfferent knds of crude ol s wdely used n long-dstance ppelne transportaton process. The energy consumpton produced by ppelne at dfferent monthly temperatures vares because the physcal propertes of crude ol mxed wth dfferent mxng ratos are unque. However, the ndustry often only formulates the mxed crude ol transportaton scheme accordng to the fxed mxng rato, thereby resultng n hgh energy consumpton of the ppelne system transportng the commngled crude ol. The optmzed mathematcal model under the mxng transportaton condtons of dfferent mxng proportons of ols was establshed to mnmze the energy consumpton n the operaton of commngled crude ol and mnmze the overall operatng costs. Dfferent blendng ratos of transportng commngled crude ol, operaton scheme of related energy consumpton equpment, and temperature and pressure parameters of outgong staton were optmzed. The optmzaton scheme for ol transportaton of dfferent mxng proportons n the typcal case was determned n the study. Results demonstrate that the number of heatng furnaces requred for operaton e s reduced after the optmzaton, and the number of heatng days also decreased by 16 days. The ex-staton pressure of each ol transportaton staton slghtly ncreases, but the ex-staton temperature s evdently reduced. The electrcty consumpton ncreases by 103,169 KWh, and the total fuel ol consumpton decreases by t. Compared wth the stuaton before optmzaton, the total energy consumpton cost of crude ol transportaton s reduced by RMB 437,500, thereby savng 26.28%. By optmzng the producton and operaton plan of the mxed proporton of crude ol transported n dfferent months, the cost of ppelne transportaton s consderably reduced, and the economc beneft of ppelne operaton s enhanced. Ths study provdes techncal support for the optmzaton of the actual operaton and producton scheme on the ol ppelne ste to an extent and may ensure the economcal and stable operaton of the ppelne n case of varyng transportaton proportons. Keywords: Ol ppelne, Blendng rato, Optmzng operaton, Energy consumpton 1. Introducton The producton and operaton optmzaton of ol ppelne requres formulatng a reasonable ol transportaton plan and operaton scheme when the basc ppelne parameters, ol transportaton equpment n each ol transportaton staton, system process, and surroundng envronmental condtons have been determned to mnmze the energy costs consumed by the throughput wthn the specfed tme. A consderable amount of energy s needed durng the producton and operaton of long-dstance ol ppelne. The energy costs come from the heatng and power costs. Owng to the hgh vscosty and easy soldfcaton characterstcs of crude ol, transportng crude ol after heatng s generally adopted, and ths process s manly acheved through burnng fuel ols n the heatng furnace. The heatng costs are produced from the ppelne operaton. The power costs come from the electrcty cost of the centrfugal pump. In general, a hgh crude ol heatng temperature n the ppelne leads to hgh heatng costs and a low-pressure requrement *E-mal address: yangka2012@sna.com ISSN: Eastern Macedona and Thrace Insttute of Technology. All rghts reserved. do: /jestr for crude ol transportaton from the frst to the last staton results n low power costs. Conversely, low heatng costs lead to hgh power costs. Hence, the problem that must be solved n the producton optmzaton of ol ppelne s fndng a set of reasonable ex-staton temperature and pressure n each ol transportaton staton to mnmze the sum of power and heatng costs. At present, the optmzed mathematcal model for the producton and operaton scheme of ol ppelne manly optmzes the equpment combnaton and operatng parameters. However, wth the rapd growth of the global economy, the demand for energy has substantally ncreased. Smultaneously, the domestc crude ol producton n Chna s decreasng yearly. The proporton of mported crude ol n the petroleum energy consumpton of Chna has gradually ncreased to ensure a steady and sustanable supply. At present, one of the techncal ssues n crude ol transportaton process n Chna s proportonally mxng domestc and mported crude ol. Optmzng the transportaton scheme n certan perods s possble due to the physcal dfferences of crude ol wth dfferent mxng proportons and the dscretzaton of ol transportaton tme and equpment combnaton scheme, combned wth the constant changes of surroundng sol temperature wth dfferent seasons and months. Currently, most theoretcal

2 studes consdered a knd of or fxed proporton of commngled crude ol [1-3]. Adjustng the adaptablty of the mxed crude ol transportaton scheme accordng to the ol transport envronment n dfferent months s dffcult. If the same mxng proporton s used to transport ol n dfferent seasons, then the energy consumpton and ppelne operatng costs wll ncrease and serously nfluence the economc benefts of the ppelne operaton. Therefore, on the bass of not changng the ppelne transportaton process equpment, the safe and smooth transportaton of crude ol mxed n a certan proporton to the desgnated place and mnmzaton of energy consumpton n ppelne transportaton must be addressed n the transportaton process of long-dstance hot ol mxng and transportaton ppelne. Based on the precedng analyss, consderng the optmzaton of equpment combnaton and operatng parameters, ths study establshed the optmzaton model through the followng steps: takng the ol transportaton proporton and ol transportaton tme correspondng to the mxng proporton as the decson varables, optmzng the ol transportaton proporton scheme n the transportaton process of commngled crude ol, reasonably adjustng the producton and schedulng scheme for commngled crude ol, and provdng the producton and operaton scheme wth mnmum energy consumpton for the transportaton of dfferent mxng proportons of ol. 2. State of the art The studes on ppelne optmzaton operaton began n the 1950s wth the ncrease n ppelne transportaton proporton n ol delvery. Kernkn, a scholar of the former Sovet Unon, poneered the optmal heatng temperature of the ppelne. The open process was the prmary method used at that tme because the pump that supples pressure to the pump staton was the recprocatng pump. The crude ol n the ppelne can be regarded as a Newton flud, and the relatonshp between the optmum outstaton temperature and other parameters can be deduced by dfferental theory. Ths theory s the bass for the optmzaton and operaton of hot ol conveyng ppelne. As the research progressvely deepened, the studes on the optmzaton model gradually changed from the pump ppelne decouplng and sngle staton-to-staton calculaton to pump ppe couplng and calculaton system model of ppe secton between dfferent statons on the entre lne to obtan study results approxmate to the actual producton. The optmzaton scope also expanded from the second-order phase to the optmzaton of all-lne pump, heatng furnace and other equpment, and operatng parameters. The ppelne transportaton process has a long hstory abroad; hence, t was early n the study of ppelne optmzaton. Gefferson [4] and others nvestgated pressure head dstrbuton n each staton and crude ol transportaton n certan throughput by the ppelne. The dynamc programmng method was used to solve t because the pressure of each pump staton s dfferent. Fnally, the optmal dstrbuton scheme of the head between statons was obtaned, and the mnmum energy consumpton under sothermal condtons was calculated. Vjerden N. G. and others selected the openng condtons of pump accordng to the dynamc energy consumpton functon of each pump and assembled the openng condtons of all pumps to the optmal scheme of the entre ppelne operaton [5]. PE Company n Germany desgned and prepared the software program on the optmal operaton scheme of crude ol and refned ol ppelne. Satsfactory results have been acheved n the optmzaton of many ol ppelnes n Europe [6]. Nguyen and Hanh H. [7] researched the combnatoral optmzaton of equpment n the schedulng scheme accordng to the genetc algorthm. The actual producton consumpton after the optmzaton suggested apparent optmzaton results. Afshar, M. H. and others selected approprate varables n the ppelne optmzaton process, solved the problems wth genetc algorthm, and mproved the searchng speed of the optmal soluton. Chebouba, A. [9] and others optmzed the ppelne wth ant colony algorthm and carred out the optmzaton calculaton wth the openng condtons of the equpment as the decson varable and the mnmum energy consumpton as the target. Ther obtaned optmzaton results are very deal. Sun F. F. and others researched the optmzed operaton of low-flow ppelnes, determned the mnmum pump flow by experments, researched the motor and pump msmatch, mproper pump selecton, savng flow and energy losses, summarzed the reasonable pump flow, and ensured the optmzed operaton of the ppelne [10]. Compared wth domestc crude ol, mported crude ol possesses good fludty and can be transported at constant temperature. The optmzaton method of domestc crude ol wll vary compared wth that of foregn ppelne due to "three hgh" (hgh condensaton, hgh vscosty, and hgh wax content) characterstcs of domestc crude ol. In addton to pressure optmzaton, temperature should be optmzed n the process of hot ol ppelne optmzaton. The domestc studes on the optmzaton of ol ppelne started late. Wu Changchun, Sun Qngfeng, and others [11] appled the two-order herarchcal optmzaton model of sngle ppelne n the double-ppelne system. Accordng to the technologcal process of producton and operaton, the optmzaton model of ol transportaton temperature was solved by the coordnate rotaton method. The optmal matchng model of pump ppelne n the second layer was solved by the dynamc programmng method. Startng wth the nvestgaton and study on the hstorcal parameters of ppelne operaton, L Yuchun adjusted the operaton scheme of nter-staton ppe segment group after the analyss and provded the safe and reasonable measures combned wth the study on ppelne operaton rsk [12]. Chen Youwang and others developed a system platform for calculatng and analyzng energy consumpton of crude ol ppelne centerng on the steady-state optmzaton calculaton model and software programmng under certan flow rate. The optmal ol transportaton scheme was determned by optmzng the ol transportaton capacty of each month. The practcal example shows that the optmzed system can effectvely optmze the ol transportaton temperature and reduce the heatng costs [13]. Sun Fafeng conducted an optmzaton study on energy-savng and emsson-reducton of the western ppelnes and proposed the correctve plan to reduce the ppelne energy consumpton and envronmental polluton. Consequently, the ppelne operaton consumpton the operatng costs were reduced [14]. L Hana and others establshed the mathematcal model of pump combnaton optmzaton under tme-sharng tarff system of peak and valley and obtaned the optmal pump combnaton and ol transportaton scheme for the average and daypartng throughput. They smultaneously analyzed the unt energy consumpton n the transportaton process of dfferent mxng proportons of crude ol and suggested that the energy savng effect for transportng ols s dfferent wth 172

3 varyng mxng proportons [15]. We Lxn and others establshed the smulaton model, whch smulates the operaton state of ppelne under dfferent workng condtons wth TLNET smulaton software, and optmzed the ppelne operaton parameters n dfferent seasons to save energy and reduce consumpton [16]. Yu Yang and others establshed the mathematcal model of optmal operaton and energy consumpton of ppelne accordng to the ppelne topology, process flow, and operatng prncple and proposed the combnaton of three energy-savng measures wth the engneerng practce: reducng ol temperature, matchng peak and valley prce, and combnng wth traffc durng the planned operaton perod [17]. W. Yuguo and others establshed the mathematcal model for the optmal operaton of super heavy ol ppelne and nvestgated the optmal operaton of heavy ol heatng ppelne n Laohe Olfeld based on the study on rheologcal propertes, vscosty and temperature characterstcs of super heavy ol ppelne, thermodynamc calculaton, and hydraulc calculaton. The operatng costs have been evdently reduced after operatng parameter optmzaton [18]. The exstng study shows that many studes by domestc and foregn scholars currently focus on ppelne optmzaton. However, the followng shortcomngs are present. Frst, the rheologcal propertes of crude ol wth dfferent blendng ratos are dfferent n the transport medum. Only a few studes dscuss the transportaton rato of commngled crude ol. Second, the enumeraton method n the combnatoral optmzaton s adopted for most combnatoral optmzaton problems at present. However, the effcency of the enumeraton method cannot meet the actual requrements wth the ncrease n mxng proporton types and the number of ste equpment. A few studes focus on mprovng the optmzaton effcency of the optmal ol transportaton scheme wth ant colony algorthm. Addressng the shortcomngs of exstng research, ths study selects the commngled crude ol mxed by Russan crude ol and Daqng crude ol n 1:1, 1:2, 1:3, 1:4, and 0:1 (pure Daqng ol) as the research objects and regards the proporton of transportng commngled crude ol and the correspondng ol transportaton tme as one of the decson varables. The present study establshes the optmzed mathematcal model for the producton and operaton scheme of ol ppelne under the mxng transportaton condtons and optmzes the schedulng program of crude ol transportaton proporton, equpment combnaton openng scheme, and operaton parameter scheme wth ant colony algorthm. Ths study also determnes the producton and operaton scheme wth the lowest energy consumpton expenses n the commngled crude ol transportaton process under the condtons of gven transmsson, temperature, and mxng proporton. The remander of ths study s organzed as follows. Secton 3 establshes the optmzed mathematcal model accordng to the operaton process of Daqng Harbn ol ppelne and provdes the soluton algorthm accordng to the model structure characterstcs. Secton 4 optmzes the typcal producton and operaton scheme and analyzes the optmzaton results. The last secton summarzes ths study and provdes the relevant conclusons. 3. Methodology 3.1 Establshment of optmzed mathematcal model The optmzaton of operaton scheme under the mxng transportaton condtons of Daqng Harbn ol ppelne manly refers to the establshment of the optmzed mathematcal model for the producton and operaton scheme. Ths model takes the ol transportaton proporton, ol transportaton tme, combnaton scheme of ol transportaton pump, heatng furnace and other equpment, ol transportaton temperature, and pressure as the decson varables. Consderng the varous safety operatng parameters and guaranteeng the temperature and pressure of the fnal staton, ths model ams to mnmze the overall energy consumpton on the premse of addressng the transportaton tasks: ( ) = ( e p W τ + e f B τ ) mn F α,τ α,δ,γ,p R,T R N x (1) =1 n n ρ gq [ a ( ) b ( ) q ] jk, 2 jk, 2 m 2 m N N h p jk, jk,, j p jk, s p, j n0 jk, n0 jk, δ pjk, j= 1 k= ηp, jηe, j W = cq ρ ( T T ) B = N N s f, j h f jk, h f out jk, f n jk, γ fjk, (3) j= 1 k= 1 Qrηf jk, s.t: Np, j δ jk, qp jk, tz = Qz, j S (4) S k = 1 Nf, j γ jk, qf jk, tz = Qz, j S (5) S k = 1 N x qτ = Qz= Qq+ Qe (6) = 1 N x τ = tz (7) = 1 [ ] Q Gmn τ (8) n n n, k = 1,..., N, j S (9) mn max jk, jk, jk, p, S Q Q Q (10) mn max fj,k f j, k f j, k T T, j S (11) n,, j mn S T T, j S (12) P out,, j max P, j S out,, j max,, j S S 6 out,, j h f,, j ξ,, j, j mn,, j S (2) (13) P 10 ρ g( h + h +Δ Z ) + P, j S (14) where α s the vector of mxng proporton; α τ s the tme vector of transportng α mxng ol; δ s the vector of pump operaton status; γ s the operaton status vector of heatng 173

4 furnace; PR s the vector of ex-staton pressure; TR s the vector of ex-staton temperature; F s the overall energy consumpton; e f s the unt prce of fuel; ep s the unt prce of electrcty; N x s the type of proporton of transportng mxng ol; B and W are the ol and power consumpton when transportng proporton of crude ol n the unt tme, respectvely; τ s the tme when transportng proporton of crude ol; N s s the total number of ol transportaton statons; N p,j s the total number of j staton pumps; N f,j s the total number of the j staton heatng furnaces; δ p, j, ks the operaton status of j pump; γ f, j, ks the j operaton status of k heatng furnace; q p, jk, ajk, bjk,, n 0 jk,, n jk,, max mn n jk,, n jk,, η p, jk, and η e, jk are the actual throughput, characterstc parameters, rated speed, actual speed, maxmum and mnmum speed, pump effcency, and k pump motor effcency of j staton, respectvely; ρ and c h are the densty and specfc heat capacty of commngled max crude ol, respectvely; q f, jk, T f n jk,, T f out jk,, η f, jk, Q f, jk, and Q are the crude ol flow, mport and export ol mn f, jk temperature, thermal effcency, maxmum and mnmum thermal load of k heatng furnace of j staton, respectvely; tz s the total schedulng tme; Q p s the total throughout; q s the flow when transportng type of mxed proporton crude ol; Q s the total quantty of Daqng crude ol before mxng; mxng; [ ] q Qe s the total quantty of Russan crude ol before Gmn τ and Q are the lowest throughput and the total throughput when transportng type of mxed proporton crude ol, respectvely; T s the allowable lowest n-staton ol temperature; T max s the hghest exstaton ol temperature; T n,, j and Tout,, j are the temperature of type of mxed proporton crude ol gong n and out of the j staton, respectvely; P out,, j, H f,, j H ξ,, j, Δ Z, j, P mn,, j, and Pmax,, j are the startng pressure, frcton loss, local frcton loss, elevaton dfference between the frst and fnal staton, the lowest n-staton pressure and the hghest ex-staton pressure n the correspondng ppe sectons n j staton when transportng type of mxed proporton crude ol, respectvely. Equatons (4)-(14) are constrants, namely, throughout, ol transportaton pump workng performance, heatng furnace heatng capacty, ol ppelne end-pont temperature, ol transportaton staton ex-staton temperature, and ol transportaton staton ex-staton pressure. 3.2 Soluton algorthm for optmzed mathematcal model In the optmzaton of Daqng Harbn ol ppelne commngled crude ol transportaton scheme, decson varables, such as the proporton of commngled crude ol, transportaton tme of the proporton of crude ol, and openng closng status of pump and heatng furnace are dscrete varables, whereas the ex-staton temperature and ex-staton pressure n each ol transportaton staton are the contnuous varables. Therefore, the optmzaton of mn h Daqng Harbn ol ppelne commngled crude ol transportaton scheme belongs to the optmal desgn of mxed varables. The problem becomes a nonlnear optmzaton problem because the nonlnear tems are ncluded n the target functon and constrants. Hence, drectly solvng ths knd of problem s very dffcult. Accordng to the characterstcs of the model, the soluton process can be dvded nto two levels. The frst level determnes the ol transportaton proporton schedule and equpment combnaton scheme, namely, the commngled crude ol transportaton proporton, transportaton tme under the proporton, and openng scheme of correspondng pumps and heatng furnace. After ascertanng the ol transportaton proporton schedule and ol transportaton combnaton scheme at the second level, the operatng parameters of exstaton temperature and pressure may be determned. The teratve soluton s needed for ths process because the parameter optmzaton and the optmzaton of equpment combnaton scheme are coupled wth each other Optmzaton of ol transportaton proporton scheme and equpment operaton scheme Ol transportaton proporton scheme s the optmzaton of transportaton proporton and transportaton tme under the proporton. The optmzaton of the equpment operaton scheme fnds the best combnaton of heatng furnace and pump under certan ol transportaton proporton schedules. The combnaton optmzaton refers to determnng a knd of ol transportaton proporton schedule and correspondng equpment openng scheme wth the mnmum energy consumpton n the planned ol transportaton cycle after the optmzaton of equpment operaton scheme. The commonly used method s enumeraton. The combnaton mode ncreases wth the ncrease n mxng proporton, the number of ste equpment, and the general schedulng. The enumeraton method clearly cannot meet the needs. Ths paper uses ant colony algorthm for solutons to mprove the effcency of the search. Regardng the ol ppelne whch has been bult and put nto operaton, the specfc model and quantty of staton pump and heatng furnace are certan. The mode of each type of pump n seres and parallel s also fxed. Therefore, the openng and closng of dfferent pumps and heatng furnaces formed the equpment combnaton mode of the ol transportaton staton. Regardng the optmal combnaton of ppelne equpment under certan ol transportaton proporton schedule, each set of equpment (pump, heatng furnace) can be regarded as a cty. The equpment start-up (1 ndcates start-up) and shutdown (0 ndcates shutdown) represent two channels to the cty. Ants are faced wth two choces when they reach the urban node of each devce. Openng or closng one devce corresponds to certan mxng proporton and ol transportaton tme. The dfferent combnatons of equpment shutdown or startup mean one combnaton channel. Regardng the optmzaton ssue of the schedulng program of crude ol transportaton proporton, relatonshps between the crude ol transportaton tme and correspondng crude ol amount under dfferent mxng proportons of transportaton schedulng programs can be generated as per the constrant of transportaton amount. Owng to the dscretzaton of the crude ol transportaton proporton and the transportaton tme, the two can be deemed as one cty, and the selected route s the crude ol transportaton proporton and the transportaton tme. Thus, when one ant completes the journey of n ctes, an entre route wll be generated, namely, a feasble soluton 174

5 of one knd of equpment combnaton of the entre ppelne under one proporton schedulng program. Under the ntal condton, f the nformaton element on each route s set as one constant, then the nformaton elements are updated and the total energy consumpton F forms one relaton when one ant completes the journey of all the n ctes. A large total energy consumpton results n less accumulated nformaton elements. Conversely, addtonal accumulated nformaton elements wll be produced. After teraton tmes, an optmal route wth the least energy consumpton wll be obtaned. The ncrement of the nformaton element can be set as kτ Δ τ =, and the formula of updated nformaton element s F as follows: kτ τ τ F 1 = 1 + (15) where τ s the current nformaton element, τ 1 s the last kτ 1 tme of nformaton element, s the updated amount of F nformaton element, F s the total energy consumpton, and K s the coeffcent Operatonal parameter optmzaton When ppelne operatonal parameter optmzaton s carred out, the temperature of crude ol transportaton shall frst be confrmed, and pressure optmzaton can then be carred out under the certan thermal condton. Durng the soluton process, the pressure varant s frst dsposed and the drect method s then appled n the nonlnear programmng method to fnd the soluton. Owng to the constrant of the crude ol temperature n the optmzaton ssue, the penalty functon method s frst adopted n the solvng process to convert the constrant nto an unconstraned nonlnear optmzaton ssue. The Powell drecton acceleraton method s then adopted to fnd the soluton. The expresson form of the penalty functon s as follows: D(T ) = F(T ) + M ( f + f ) (16) out out k 1 2 f1= max( Tout Tout,max,0) 2 (17) optmal operatonal parameters under the combnaton program, thereby calculatng the correspondng objectve functon value. The nformaton elements are updated on the route as per the nformaton element update formula to fnally acheve the maxmum power of teraton. The optmal soluton of the ssue s thereafter obtaned. The procedure of calculaton s as follows: Confrm the crude ol transportaton tmeand amount under mxng proporton Read the parameters of ppelne and equpment foundaton Intalze the algorthm parameters Nc=Nc+1 Select the next cty node as per the probablstc Whether to complete a tour? yes Calculaton of the total energy consumpton of objectve functon No transportaton program ant k=1 ant k=k+1 Modfy the tabu k ant populaton m? Yes No Output the optmzaton result Optmzaton of operatonal Update the nformaton elements as per the formula Whether the completon condtons have been Yes satsfed Fg. 1. Block Dagram of Algorthm Process No f2 = max( Tout,mn Tout,0) 2 (18) 4 Result Analyss and Dscusson where M k s the penalty factor General solvng process of optmzaton The precedng analyss shows that the general solvng thought of optmzaton can be summarzed as follows: Accordng to the constrant of transportaton amount, the relatonshp between the crude ol transportaton tme and transportaton amount under dfferent mxng ratos of transportaton schedulng program can be confrmed. The ant colony algorthm can be adapted to optmze the crude ol transportaton rato schedulng program and the startng program of equpment at each staton. One entre route for each ant as per the probablstc transton rules s confrmed, ths route s one of the equpment combnaton programs under a knd of mxng rato transportaton program. The ppelne operaton parameters are optmzed to confrm the Ths study selects the producton and operaton program of the ol ppelne from Daqng Olfeld of CNPC to Harbn Refnng and Chemcal Factory as the optmzaton object. Ths ppelne was put nto formal operaton n November The crude ol n the ppelne s the crude ol mxed per certan rato wth the crude ol from Daqng Olfeld of CNPC and Russan crude ol. The ppelne s km long n total wth a ppe dameter of φ mm and a bured depth of 1.5 m. Along the entre lne, the followng four crude ol transportaton statons are set up: the frst staton, the No. 1 mddle staton, No. 2 mddle staton, and the end staton. Among whch, the frst and the No. 2 mddle statons are equpped wth pumps and heatng furnaces, whereas the No.1 mddle staton s only equpped wth one heatng furnace. 175

6 After optmzaton of the producton and operatonal program of ths ppelne n September 2015, the planned tme of crude ol transportaton s 30 days, the planned total amount of Russa Daqng commngled crude ol s t, and the transportaton proporton s 1:3. The temperature of Russan crude ol s 12.3 and that of the Daqng crude ol s Optmzaton result of the producton and operaton program Fgures 1 and 2 present the general operatonal program before and after optmzaton of the ppelne n September 2015, respectvely. The proporton and tme of crude ol transported, equpment startng program, ex-staton temperature, and pressure parameters have evdently been optmzed. Before optmzaton, the crude ol transportaton proporton schedulng program s 1:3, and the transportaton tme s 30 days. After optmzaton, the proporton s 1:1 wth transportaton tme of 16 days, and the proporton s 0:1 (pure Daqng ol) wth transportaton tme of 14 days. The startng program of pump does not consderably change. Whle transportng commngled crude ol wth a mxed proporton of 1:1, 2# ol transfer pump s substtuted by the 3# ol transfer pump. Whle transportng the commngled crude ol wth a mxed proporton of 0:1, the 1# Daqng and the 2# Russa ol supply pumps are closed, the 2# Daqng ol supply pump s open. The startng program of heatng furnace s consderably adjusted. The condensaton ponts of 1:1 commngled crude ol s low, and 16 days of contnuous transportaton wthout heatng can be realzed wth the assstance of the ntal ol temperature of the two knds of crude ol untl the ol s transported to the end staton. Therefore, the heatng furnace does not need to be opened n the transportaton of 1:1 commngled crude ol. The 3# heatng furnace at the frst staton s closed n the transportaton of 0:1 commngled crude ol because the supply temperature of Daqng ol s hgh. Although the exstaton ol temperature at each staton slghtly ncreased n transportaton of 0:1 commngled crude ol after optmzaton, the ex-staton temperature of 1:1 commngled crude ol consderably decreased. Therefore, the ex-staton temperature consderably decreased as a whole. The exstaton pressure of each staton under the two knds of mxed proporton slghtly ncreased compared wth that before optmzaton. The ex-staton temperature of each crude ol transportaton staton consderably decreased. The comparatve stuaton of varous knds of energy consumpton before and after optmzaton s shown n Table 3. Table 1. General Operaton Program before Optmzaton Ol transportaton proporton Delvery tme (day) Throughput (t/d) Staton yard Transportaton pump: Ol supply pump Heatng furnace Outlet temperature ( ) Ex-staton pressure (MPa) Mxed proporton of Russan crude ol and Daqng crude ol s 1:3 Delvery Frst staton No. 1 mddle staton No. 2 mddle staton 2# 1#Daqng 2#Russan 3# # # Table 2. General Operaton Program after Optmzaton Ol transportaton proporton Delvery tme (day) Throughput (t/d) Staton yard Transportaton pump: Ol supply pump Heatng furnace Outlet temperature ( ) Ex-staton pressure (MPa) Mxed proporton of Russan crude ol and Daqng crude ol s 1:1 Delvery Frst staton No. 1 mddle staton No. 2 mddle staton 3# 1#Daqng 1#Russan Mxed proporton of Russan crude ol and Daqng crude ol s 0:1 Delvery Frst staton No. 1 mddle staton No. 2 mddle staton 2# 2#Daqng # # Calculaton of energy consumpton of ppelne Table 3 compares the energy consumpton before and after optmzaton of the ppelne n September, Although 176 the consumpton of electrcty ncreased by 103,169 KWh after optmzaton, the total consumpton amount of fuel ol

7 decreased by t. Compared wth the stuaton before optmzaton, the total energy consumpton costs of crude ol transportaton reduced by RMB 437,500, thereby savng 26.28%. Table 3. Comparson of Energy Consumpton before and after Optmzaton Total consumpton amount of water electrcty (KWh) Total consumpton amount of fuel ol (t) Total costs of crude ol transportaton (RMB*10,000) Before After Before Before After optmzaton optmzaton optmzaton optmzaton optmzaton After optmzaton 758, , Savngs (%) Conclusons Ths study targeted the ssue that crude ol transportaton of commngled crude ol transportaton ppelne wth the same mxed proporton n dfferent seasons could result n hgh energy consumpton n crude ol transportaton of the entre ppelne. Based on a comprehensve consderaton of effects of equpment combnaton and operatonal parameters on energy consumpton, ths study ncluded the proporton of ol transported and the ol transportaton tme correspondng to the mxed proporton of transportaton nto the varants of decson. The mathematcal model of mxed transportaton ppelne optmzaton was set up to target the mnmum total energy consumpton. Herarchcal solvng was performed wth the ant colony algorthm and the Powell drecton acceleraton method featurng the penalty functon for the structural layer of the model. When the total crude ol throughput, ntal temperature, and the mxed proporton of crude ol were gven, ths study carred out optmzaton research on the ol transportaton proporton schedulng program, the equpment combnaton startng program, and the operatonal parameter program. The followng conclusons are drawn: (1) After optmzaton of the crude ol transportaton proporton schedulng program and the equpment operatonal program under each ol transportaton proporton, the operatonal stuaton of pump slghtly changed, the number of heatng furnace under varous knds of ol transportaton proporton decreased, and the number of days commngled crude ol heatng va openng the heatng furnace consderably decreased. Under the 1:1 ol transportaton proporton, the commngled crude ol can be contnuously transported usng the ntal ol temperature wthout heatng for 16 days untl t s transported to the end staton. (2) After optmzaton of crude ol transportaton proporton schedulng program and the ppelne operatng parameters under each ol transportaton proporton, the exstaton pressure of each transportaton staton under each ol transportaton proporton slghtly ncreased compared wth that before optmzaton, and the ex-staton temperature of each ol transportaton staton sgnfcantly decreased. (3) Compared wth the stuaton before optmzaton, the power consumpton after optmzaton sgnfcantly decreased, and the total energy consumpton of crude ol transportaton ppelne also decreased. Therefore, the energy savng effect of the ppelne producton operatonal program after optmzaton of crude ol transportaton proporton was apparent. In summary, ths study comprehensvely consdered the nfluence of dfferent knds of mxed proporton and the transportaton tme of ppelne crude ol transported on the optmzaton target functon, confrmed the optmal ol transportaton proporton program, the correspondng pump combnaton, and the optmal operatonal parameters wthn one perod of crude ol transportaton, and provded convenent and accurate technology support for the optmzaton of producton and operaton program under mxed transportaton condtons on the crude ol transportaton ste. However, a smlar proporton of commngled crude ol leads to small physcal propertes. 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