本文關(guān)鍵詞： 余熱發(fā)電 （火用） （火用）損失 聯(lián)合（火用）效率 系統(tǒng)優(yōu)化　出處：《青海大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：水泥行業(yè)是高耗能的產(chǎn)業(yè),近年來(lái)雖然水泥熟料生產(chǎn)技術(shù)取得了很大的進(jìn)步,但水泥行業(yè)的能耗依然很高,采用低溫余熱發(fā)電技術(shù)是降低水泥行業(yè)能耗的最好途徑之一。青海地處高海拔地區(qū),年平均氣溫比低,晝夜溫差大,大氣壓力低,受高原氣候的影響,低溫余熱發(fā)電系統(tǒng)的發(fā)電效率較低。本文依托《水泥行業(yè)低溫余熱發(fā)電系統(tǒng)高原適應(yīng)性研究及示范》項(xiàng)目,對(duì)青海省典型水泥生產(chǎn)企業(yè)的低溫余熱發(fā)電系統(tǒng)進(jìn)行熱力學(xué)分析,并對(duì)低溫余熱發(fā)電系統(tǒng)進(jìn)行優(yōu)化,達(dá)到提高發(fā)電效率的目的。通過(guò)質(zhì)量守恒定律和熱力學(xué)第一定律,對(duì)整個(gè)余熱發(fā)電系統(tǒng)進(jìn)行了物質(zhì)流和能量流分析,結(jié)果表明:能量的損失主要集中在汽輪機(jī)、乏汽、廢氣、鍋爐和蒸汽管道散熱和循環(huán)水等環(huán)節(jié)。其中循環(huán)水和AQC爐出口廢氣所含的能量分別為114.10GJ/h和30GJ/h,能量從數(shù)量上的損失大。但是將熱力學(xué)第一定律和第二定律相結(jié)合,通過(guò)(火用)分析后,結(jié)果表明:AQC爐出口廢氣帶出的（火用）只有3.46 GJ/h,相對(duì)較小,而且廢氣溫度低于85℃,回收利用價(jià)值不大。凝汽器中由循環(huán)水帶走的（火用）為4501.2MJ/h,這部分（火用）只占到整個(gè)系統(tǒng)帶入（火用）的4.5%,因而想通過(guò)減少循環(huán)水的（火用）損失來(lái)提高整個(gè)系統(tǒng)的（火用）效率,空間比較有限。而汽輪機(jī)、AQC爐、SP爐才是提高（火用）效率的關(guān)鍵環(huán)節(jié),它們的（火用）損失分別占到系統(tǒng)（火用）損失的40.67%、20.33%、21.31%。對(duì)汽輪機(jī)和余熱鍋爐進(jìn)行參數(shù)優(yōu)化,降低這部分（火用）損失能有效地提高整個(gè)余熱發(fā)電系統(tǒng)的（火用）效率。分別研究了主蒸汽溫度、主蒸汽壓力、節(jié)點(diǎn)溫差和接近點(diǎn)溫差對(duì)AQC爐、SP爐、汽輪機(jī)和聯(lián)合（火用）效率的影響,并通過(guò)研究各參數(shù)對(duì)聯(lián)合（火用）效率的影響,發(fā)現(xiàn)參數(shù)對(duì)聯(lián)合（火用）效率的影響由大到小的順序是主蒸汽溫度、主蒸汽壓力、節(jié)點(diǎn)溫差和接近點(diǎn)溫差。最終選擇主蒸汽溫度和主蒸汽壓力作為優(yōu)化參數(shù),對(duì)鍋爐和汽輪機(jī)進(jìn)行聯(lián)合優(yōu)化。優(yōu)化后AQC爐的（火用）損失為8.5906×106 k J/h,SP爐的（火用）損失為6.8362×106 k J/h,汽輪機(jī)的（火用）損失為1.3615×106 k J/h,比優(yōu)化前分別降低1.38%、2.52%和2.19%,優(yōu)化后系統(tǒng)的發(fā)電量可以從7.12Mw提高到7.65Mw。汽輪機(jī)出口乏汽帶出的（火用）為11478MJ/h,乏汽?的大小不僅與進(jìn)汽輪機(jī)參數(shù)和汽輪機(jī)的性能有關(guān),還與凝汽器的真空度有關(guān)。研究了凝汽器真空度與發(fā)電量的關(guān)系,給出了提高凝汽器的真空度方案。通過(guò)增加循環(huán)水量、增設(shè)噴淋裝置、換裝高效真空抽氣系統(tǒng)和增大傳熱系數(shù)的措施后,凝汽器的真空度提高了0.006MPa,每小時(shí)提高發(fā)電量640kwh,效果顯著。
[Abstract]:Cement industry is a high-energy industry. Although cement clinker production technology has made great progress in recent years, the energy consumption of cement industry is still very high. Low temperature waste heat power generation technology is one of the best ways to reduce energy consumption in cement industry. Qinghai is located at high altitude, with low annual average temperature ratio, large diurnal temperature difference, low atmospheric pressure and influenced by plateau climate. The low temperature waste heat power generation system has low power generation efficiency. This paper relies on "cement industry low temperature waste heat generation system plateau adaptability research and demonstration" project. Thermodynamics analysis and optimization of low temperature waste heat power generation system in typical cement production enterprises in Qinghai Province are carried out. Through the mass conservation law and the first law of thermodynamics, the mass flow and energy flow of the waste heat generation system are analyzed. The results show that the energy loss is mainly concentrated in the steam turbine. Exhaust gas, waste gas, boiler and steam pipeline, heat dissipation and circulating water. The energy content of circulating water and AQC outlet waste gas are 114.10GJ / h and 30GJ / h respectively. The loss of energy is large in quantity. But after combining the first law of thermodynamics with the second law, it passes exergy analysis. The results show that the exergy of the exhaust gas from the outlet of the 1: AQC furnace is only 3.46 GJ / h, which is relatively small, and the waste gas temperature is lower than 85 鈩，

本文編號(hào)：1492149