煤制甲醇氣化與變換單元的能效優(yōu)化

第31卷第5期計算機與應用化學(xué)Vol.31, No.52014年5月28日.Computers and Applied ChemistryMay 28, 2014煤制甲醇氣化與變換單元的能效優(yōu)化齊少寧'，李士雨'*李金來(lái)2(1.天津大學(xué)化工學(xué)院，天津，300072;2.新奧科技發(fā)展有限公司，河北，廊坊，065001)摘要:以某60萬(wàn)噸/年煤制甲醇裝置為背景，選取氣化與變換單元為研究對象，利用夾點(diǎn)技術(shù)對其用能現狀進(jìn)行了分析，找出違背夾點(diǎn)規則的不合理?yè)Q熱匹配并提出2套優(yōu)化方案，結果如下:方案1:減少副產(chǎn)0.3 Mpag蒸汽53.8% (工廠(chǎng)該品質(zhì)蒸汽過(guò)剩),增產(chǎn)1.2 Mpag蒸汽6.5 %,新增產(chǎn)2.5 Mpag蒸汽18.83 MW;方案2:減少0.3 Mpag蒸汽51.0 %,增產(chǎn)1.2 Mpag蒸汽22.2 %。當1.2與2.5 Mpag蒸汽價(jià)格相差不大、設備材料費用較高時(shí)，方案2優(yōu)于方案1.關(guān)鍵詞:夾點(diǎn)技術(shù):換熱網(wǎng)絡(luò );煤炭氣化;變換;煤制甲醇中圖分類(lèi)號: TQ546.4文獻標識碼: A文章編號: 1001-4160(2014)05-601-604DOI: 10.11719/com. app.chem20140519工智能法[23)以?shī)A點(diǎn)技術(shù)法141。其中，夾點(diǎn)技術(shù)法!"由于1引言其簡(jiǎn)單、直觀(guān)、計算量小而得到了廣泛的應用。夾點(diǎn)技氣化和變換是煤制甲醇工藝的上游單元，系統高溫術(shù)在煉油16-8、石油化工9-10)及其他化工裝置01]等都取得物流的溫度高達415 C，而最終要降到40 C左右，因了顯著(zhù)的節能效果，但是在煤炭氣化和變換工業(yè)的應用此可以通過(guò)副產(chǎn)蒸汽回收系統能量用于后續單元。根據報道不多。熱力學(xué)第二定律可知，能量具有不同的品質(zhì)。高壓蒸汽本文以某廠(chǎng)60 萬(wàn)噸/年煤制甲醇裝置為背景，選取具有的能量品質(zhì)高于低壓蒸汽具有的能量品質(zhì)。故而，處于上游的煤炭氣化與變換單元作為1個(gè)系統，利用夾可以通過(guò)提高高壓蒸汽的產(chǎn)量、降低低壓蒸汽產(chǎn)量對氣點(diǎn)技術(shù)法對該系統的用能現狀進(jìn)行了分析，在此基礎上化和變換工藝進(jìn)行能效優(yōu)化，提高能量回收效益。提出了2套優(yōu)化方案，顯著(zhù)降低了低壓蒸汽的產(chǎn)量、提目前運用的能效優(yōu)化方法主要有數學(xué)規劃法"3)、人高了高壓蒸汽的產(chǎn)量。Water slurryE0413H1+H3E06E05_HEOWaterE07c114E0901|TO1V0502V0Waste waterE10ECH1H4C12Syngas個(gè)C1O17-V01-02|HV035-1 E0ro204|CondensateR01- -gasifier; R02- shift converter; T01 - -syngas scrubber; T02- ammonia scrubber, V01- -HP flash drum;'vacuum flash drum; V04- NO.2 vacuum flash drum; V05- -NO.1 water separator; V06- -NO.1 water separator, Hi- hot stream i; Cj - cold streamjR01-氣化爐; R02- 變換爐; T01-洗滌塔; T02- 洗氨塔; V01-高壓閃蒸罐; V02- 低壓閃蒸罐; V03- 第一 真空閃蒸罐; V04- 第二真空閃蒸罐V05- 第一 -水分離器: V06- 第二水分離器: Hi- 第i股熱物流; Cj- 第j股冷物流Fig.1l Process flowchart of coal gasification and shift units.圖1煤炭氣化 與變換工藝流程圖收稿日期: 2013-08-18; 修回日期: 2013-11-14作者簡(jiǎn)介:齊少寧(1987- -),女河北人，，碩士研究生，E-mail: shaoning19871016@126.com聯(lián)系人:李士雨(1964- ),男，天津人，博士，教授，E-mail: shyli126@126.com.2014, 31(5)齊少寧，等: 煤制甲醇氣化與變換單元的能效優(yōu)化603冷卻器，H1和H1+H3溫度均在該夾點(diǎn)以上,卻被夾點(diǎn)以下又可以消除E07跨越公用工程夾點(diǎn)換熱、提高冷公用工程的C9和CU3冷卻。的溫度。②公用工程夾點(diǎn)2處: E07 為H1+H3的冷卻器，溫度②新增冷卻器NO2: H3的溫度在公用工程夾點(diǎn)1以下，在該夾點(diǎn)以上，卻用了CU2冷卻。將E06移到H3.上,消除了跨越公用工程夾點(diǎn)的不合理?yè)Q熱。③公用工程夾點(diǎn)3處: EI0 為HS冷卻器，溫度在該夾H3剩余的能量通過(guò)新加冷卻器NO2副產(chǎn)0.3 Mpag蒸汽回點(diǎn)以下，卻用C12來(lái)冷卻; E02、 E11 為H6和H7冷卻器，收。雖然工廠(chǎng)0.3 Mpag蒸汽是過(guò)剩的，但是通過(guò)新增冷卻溫度在夾點(diǎn)以上，卻用冷卻水冷卻。器N01已經(jīng)降低很多，同時(shí)多余的蒸汽除用于工藝外，還4152 E05380.040206.6s0.可以供給辦公區應用、用于冬季供暖等，所以這部分的能量回收還是十分必要的。H1+H3240.8 E0421504.2改造方案2179.5 E01 1749H4HSEI0換熱網(wǎng)絡(luò )的改造過(guò)程中冷公用工程為循環(huán)冷卻水、460.3 Mpag發(fā)生蒸汽、1.2 Mpag發(fā)生蒸汽，不再副產(chǎn)新的H19H82.5 Mpag蒸汽。利用Aspen Energy Analyzer軟件分析得，系統夾點(diǎn)為公用工程夾點(diǎn)2和工藝夾點(diǎn)，能量目標如表C1262023所示，對現有換熱網(wǎng)絡(luò )分析發(fā)現換熱器E05不再跨越CUI夾點(diǎn)，其他跨越夾點(diǎn)的換熱器不變。CU2CU3改造后的換熱網(wǎng)絡(luò )如圖5所示，節能效果如表3所226示。具體內容如下:X-13SMwW XP-209MwxP-4.SMW新增冷卻器N03: H1+H3 初溫為306.9 C，位于公用工程夾點(diǎn)2以上，新增冷卻器N03回收該物流夾點(diǎn)以XP - energy cossing pinch; CUI - coling water; CU2 -0.3Mpagsteam generation; CU3 - 1.2 Mpag steam generation; CU4 - 2.5上的能量;該物流夾點(diǎn)以下的能量用來(lái)預熱1.2 Mpag、Mpag generation0.3 Mpag發(fā)生蒸汽的鍋爐給水。XP -跨越夾點(diǎn)傳遞的能量: CU1- 循環(huán)冷卻水: CU2 -0.3 Mpag發(fā)生蒸汽: CU3- 1.2 Mpag發(fā)生蒸汽; CU4 - 2.5 Mpag發(fā)生蒸汽與方案1相比，方案2只需新增1個(gè)換熱器，設備Fig.3 The grid diagram of current HEN.投資低; 1.2 Mpag蒸汽產(chǎn)量大幅提高。圖3現有換熱網(wǎng)絡(luò )級聯(lián)圖4152 EO503即71574甲醇裝置氣化與變換單元的節能改造HI+H3品E04215.09.5 E01 1749工廠(chǎng)副產(chǎn)的0.3 Mpag蒸汽嚴重過(guò)剩，所以節能改造400H5的主要目標是降低0.3Mpag的產(chǎn)量、提高1.2與2.5Mpag17蒸汽的產(chǎn)量。E03 427c9 200。4.1 改造方案1188Cil415.2 EOSE07 1572408 EO4 2150N02157CU1H|142730CU3 19￥EO3 427250.0xP-0.0MWxP-4.5MW176Fig.5 The grid diagram of second optimized HEN.86圖5 改造方案2的換熱網(wǎng)絡(luò )級聯(lián)圖142550表3換熱網(wǎng)絡(luò ) 各級公用工程消耗0Table 3 The uiltis consumption of HEN.CU4 2.110 |公用工程現有換熱目標1方案1目標2 方案2UtilityxMw xIF0wwxp-23Mwsolution1 target2solution2MWcurent HEN↓Fig.4 Grid diagram of first optimized HEN.22.9918.5 22.9918.5圖4改造方案 1的換熱網(wǎng)絡(luò )級聯(lián)圖U248.6626.9722.4823.82111.9117.8 119.2 138.1136.7改造后的換熱網(wǎng)絡(luò )如圖4所示，節能效果如表3所CU420.29 18.83①新增冷卻器NO1:HI被C9冷卻后溫度高達380.9 C，5結論新添加冷卻器N01副產(chǎn)2.5 Mpag 蒸汽18.83 MW，剩余部分熱量由E07回收。這樣既可以副產(chǎn)2.5 Mpag高壓蒸汽，氣化和變換單元是煤制甲醇工藝的上游單元，可以604什算機與應用化學(xué)2014, 31(5)通過(guò)提高高壓蒸汽的產(chǎn)量、降低低壓蒸汽產(chǎn)量對氣化和13 Li Jun. GE coal-water slurry gasifcation process overview. AnhuiChemical Industry, 2001, 01:46-49.變換工藝進(jìn)行能效優(yōu)化，提高能量回收效益。14 Zhang Xudong and Bao Zonghong. Study on GE coal-water slurry氣化與變換工藝為只需要冷公用工程的閾值問(wèn)題。gasifcation equipment design. Journal of Chemical Industry and本文利用夾點(diǎn)技術(shù)法找到了跨越工藝和公用工程夾點(diǎn)的15 Xiao Jiefei, Chen Guangqing and Zong Qiuyun. QDB-03不合用能之處。并針對上述問(wèn)題提出了2套優(yōu)化方案。application at high pressure sulfur tolerant shift unit in GEpressurized coal water gasification process. Chemical Engineering方案1:使得工廠(chǎng)嚴重過(guò)剩的0.3 Mpag低壓蒸汽量Design Communications, 2011, 37(2):75-77.降低了53.8 %，工廠(chǎng)有用的1.2 Mpag蒸汽量提高了16 Ye Xin and Ding Ganhong. Application of pinch tchnology in thecoal-to-methanol process. Coal Chemical Industry, 2010, (3):1-6.6.5 %，另外副產(chǎn)了新的2.5 Mpag高壓蒸汽18.83 MW;17 Kemp Ian C. Pinch analysis and process integration.2nd ed. USA:Elsevier Ltd, 2007.方案2: 0.3 Mpag蒸汽產(chǎn)量降低了51.0 %, 1.2 Mpag蒸汽產(chǎn)量提高了22.2 %。中文參考文獻當1.2與2.5 Mpag蒸汽價(jià)格相差不大、設備材料費張俊峰，羅雄麟.換熱網(wǎng)絡(luò )設計方法的研究進(jìn)展[].化工進(jìn)展,用較高時(shí)，方案2優(yōu)于方案1.2005，6(24) :625-628.? 李志紅,華賁,尹清華,等.人工智能與數學(xué)規劃的集成用于References:換熱網(wǎng)絡(luò )最優(yōu)合成設計的研究[]石油化工, 1998, 09:36-44.Zhang Junfeng andLuo Xionglin. Recent advances in optimal3 趙輝,丁曉明，陳宏剛，等.換熱網(wǎng)絡(luò )綜合方法的研究進(jìn)展[].synthesis of heat exchanger networks. Chemical Industry andEngineering Process, 2005, 6(24):625-628.計算機與應用化學(xué), 2009, 26(10):1315-1318.?Li Zhihong, Hua Ben and Yin Huaqing, The study design of heat;劉智勇，李志偉,霍磊.夾點(diǎn)理論及其在換熱網(wǎng)絡(luò )中的優(yōu)化分exchanger networks synthesis with integrated artificial intelligence析[J]. 節能技術(shù), 2012, 30(17):273-277.and mathematical programming method. PetrochemicalTechnology, 1998, 09:36-44.5 王成運.過(guò)程集成節能工藝夾點(diǎn)分析[D].中國石油大學(xué), 2011.3 Zhao Hui, Ding Xiaoming and Chen Honggang. 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Pinch analysis and optimization of VCM devices.372)75-77.Zhejiang University, 2005.Energy efficiency optimization of gasifcation and shift process in coal tomethanolQi Shaoning', Li Shiyu1* and Li Jinlai2(1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China)(2. ENN Research and Development Co Ltd, Langfang 065001, Hebei Province, China)Abstract: The energy eficiency of coal gasification and CO shit process of a 600 kt/a coal to methanol device was studied through pinchtechnology. The results showed that the existing process had a huge energy saving potential because a great amount cross pinch heat transferexisted there. In order to recover high grade energy from this process, two suggested solutions were published in this paper. Solution 1:reducing 0.3 Mpag steam by 53.8 % which is overproduction in current factory; increasing 1.2 Mpag steam by 6.5 % and newly producing 2.5Mpag steam 18.83 MW. Solution 2: reducing 0.3 Mpag steam by 51.0 % and increasing 1.2 Mpag steam by 22.2 %. If the price dfferencebetween the 1.2 and 2.5 MPag steams is small and the equipment material is expensive, the solution 2 is better.Keywords: pinch technology; heat exchanger network(HEN); coal gasifcation; shft process; coal to methanol(Received: 2013-08-18; Revised: 2013-11-14).