發(fā)布時間：2018-05-25 05:07

  本文選題：超臨界機組 + 熱力系統(tǒng)��； 參考：《華北電力大學》2017年碩士論文

【摘要】：能源是我國經(jīng)濟發(fā)展的重要支柱和動力,隨著全球資源的日漸枯竭以及環(huán)境問題的日趨嚴重,如何實現(xiàn)節(jié)能減排是當今社會實現(xiàn)可持續(xù)發(fā)展所面臨的主要問題。在我國的能源發(fā)電結構中,火力發(fā)電仍然占據(jù)著主要地位,而超臨界機組因其節(jié)能高效的特點,已逐漸成為我國火力發(fā)電機組中的主力機組。因此對超臨界機組進行能效分析具有重要的現(xiàn)實意義�；痣姍C組在實際運行中,熱力系統(tǒng)參數(shù)不可能一直維持不變。當熱力系統(tǒng)參數(shù)發(fā)生變化時,不可避免的會對機組的熱經(jīng)濟性產生影響。為了研究超臨界機組熱力系統(tǒng)擾動對機組能效的影響情況,針對超臨界機組熱力系統(tǒng)結構特點,對其進行建模分析及熱經(jīng)濟性計算。主要研究內容和成果如下:(1)根據(jù)能量守恒方程和質量守恒方程,改進了熱力系統(tǒng)熱經(jīng)濟性分析統(tǒng)一模型和多元擾動下熱力系統(tǒng)能效分析模型,將直接進出汽輪機側的輔助汽水對機組能效的影響加入模型中,使模型更加完善。(2)以矩陣的微積分運算法則為基礎,推導了多元擾動下的熱力系統(tǒng)能效分析模型的積分模型,并根據(jù)不同類型擾動對機組熱力系統(tǒng)熱力參數(shù)的影響特點,建立了適用于局域性擾動和廣域性擾動的能效分析模型。以某660MW超臨界機組為例驗證了模型的正確性,比較了積分模型和原模型在一定擾動范圍內的準確性。(3)計算了算例機組的廣域性擾動敏感度系數(shù)。通過計算可知:在100%THA負荷下,主汽壓擾動絕對敏感度系數(shù)為0.00158/MPa,主汽溫擾動絕對敏感度系數(shù)為0.000162/℃,再熱汽溫擾動絕對敏感度系數(shù)為0.000121/℃。且隨著機組負荷的降低,主汽壓擾動和再熱器溫擾動對機組能效的影響程度逐漸增大,主汽溫擾動對機組能效的影響程度逐漸減小。(4)計算了算例機組的局域性擾動敏感度系數(shù)。計算結果表明:隨著機組負荷的降低,輔助汽水流量擾動對機組能效的影響程度逐漸增大,而且輔助汽水回收利用跨越能級越大其對機組能效的影響程度越大;各級加熱器抽汽壓損擾動對機組能效的影響程度逐漸減小;上端差擾動對機組能效的影響程度基本不變。此外,1號加熱器和6號加熱器的上端差擾動和抽汽壓損擾動的敏感度系數(shù)要明顯高于其他加熱器,在機組運行中應重點監(jiān)測1號加熱器和6號加熱器的運行狀態(tài)。(5)計算了算例機組廣域性多元組合擾動對機組能效的影響,并與原模型和常規(guī)熱平衡法比較。計算結果表明;在計算廣域性多元組合擾動時,積分模型與常規(guī)熱平衡法之間的相對誤差不超過3.5%,且準確性在整體上要略高于原模型。(6)分析比較了不同類型擾動的相對敏感度系數(shù)。結果表明:廣域性擾動對機組能效的影響要遠遠大于局域性擾動,而工質溫度對機組能效的影響要大于工質壓力對機組能效的影響;主蒸汽壓力擾動相對敏感度系數(shù)基本不隨負荷變化而變化。
[Abstract]:Energy is an important pillar and motive force of China's economic development. With the depletion of global resources and the increasingly serious environmental problems, how to achieve energy saving and emission reduction is the main problem that the society faces to achieve sustainable development. The thermal power generation still occupies the main position in the energy generation structure of our country, and the supercritical unit has become the main unit in our country because of its energy saving and high efficiency. Therefore, the energy efficiency analysis of supercritical units has important practical significance. In the actual operation of thermal power units, the thermodynamic system parameters can not always remain unchanged. When the thermodynamic system parameters change, the thermal economy of the unit will inevitably be affected. In order to study the influence of thermal system disturbance of supercritical unit on unit energy efficiency, the thermal system of supercritical unit was modeled and analyzed and its thermal economy was calculated according to the structural characteristics of thermal system of supercritical unit. The main research contents and results are as follows: (1) according to the energy conservation equation and mass conservation equation, the unified thermal economic analysis model of thermal system and the energy efficiency analysis model of thermal system under multivariate perturbation are improved. The influence of auxiliary steam water directly in and out of steam turbine side on unit energy efficiency is added to the model to make the model more perfect. Based on the matrix calculus algorithm, the integral model of energy efficiency analysis model of thermal system under multivariate disturbance is derived. According to the influence of different types of disturbances on the thermodynamic parameters of unit thermal system, an energy efficiency analysis model suitable for local disturbance and wide area disturbance is established. The correctness of the model is verified by taking a 660MW supercritical unit as an example. The accuracy of the integral model and the original model in a certain disturbance range is compared. The calculation results show that under 100%THA load, the absolute sensitivity coefficient of the main steam pressure disturbance is 0.00158% MPA, the absolute sensitivity coefficient of the main steam temperature disturbance is 0.000162 / 鈩，

本文編號：1932198