【摘要】：工業(yè)是我國(guó)能源消費(fèi)的最主要部門，我國(guó)工業(yè)能耗占總能耗的70%以上，但其能源的利用率非常低，工業(yè)能耗中很大一部分的能量轉(zhuǎn)化為載體不同、溫度不同的工業(yè)余熱。以鋼鐵行業(yè)燒結(jié)工序?yàn)槔瑹Y(jié)工序中就有50%左右的熱能被燒結(jié)煙氣和冷卻機(jī)廢氣帶走，廢氣帶走的顯熱占燒結(jié)總能耗的20%以上�？梢姡I(yè)余熱的高效綜合利用是實(shí)現(xiàn)我國(guó)節(jié)能減排戰(zhàn)略目標(biāo)的重要途徑。采用低沸點(diǎn)有機(jī)工質(zhì)為循環(huán)工質(zhì)的有機(jī)朗肯循環(huán)發(fā)電是中低溫余熱資源利用的一種有效方式。有機(jī)工質(zhì)流動(dòng)沸騰換熱系數(shù)的測(cè)定是有機(jī)朗肯循環(huán)發(fā)電系統(tǒng)的一個(gè)重要組成部分，本文對(duì)有機(jī)工質(zhì)的管內(nèi)流動(dòng)沸騰換熱特性進(jìn)行了數(shù)值模擬分析；設(shè)計(jì)和搭建了雙循環(huán)有機(jī)工質(zhì)沸騰換熱特性實(shí)驗(yàn)系統(tǒng)，為低溫余熱有機(jī)朗肯循環(huán)發(fā)電用有機(jī)工質(zhì)換熱特性的進(jìn)一步實(shí)驗(yàn)研究奠定了基礎(chǔ)。 論文首先對(duì)氣液兩相流的基本參數(shù)和流動(dòng)沸騰換熱的特征進(jìn)行了分析。分析了截面含氣率及截面含液率、質(zhì)量流量、質(zhì)量含氣率、質(zhì)量流速、體積流量、體積含氣率、汽相真實(shí)流速、汽相折算流速、滑動(dòng)比、滑動(dòng)速度、兩相流的流型、水平管流動(dòng)沸騰換熱的區(qū)域等流動(dòng)沸騰換熱的基本特征。 然后對(duì)有機(jī)工質(zhì)管內(nèi)的流動(dòng)沸騰換熱特性進(jìn)行了數(shù)值分析研究。建立了有機(jī)工質(zhì)管內(nèi)換熱模型，模型包括湍流模型和多相流模型。利用CFD軟件，對(duì)兩種典型有機(jī)工質(zhì)R245fa和R123在水平光滑管內(nèi)的流動(dòng)沸騰換熱特性進(jìn)行了分析計(jì)算，得到R245fa和R123在水平管內(nèi)的流動(dòng)沸騰換熱過程中的溫度場(chǎng)、速度場(chǎng)、和換熱系數(shù)的分布及變化規(guī)律。通過改變?nèi)肟谶吔鐥l件，模擬出了工質(zhì)質(zhì)量流速、蒸發(fā)溫度、工質(zhì)加熱溫度對(duì)沸騰換熱的影響規(guī)律。 模擬分析結(jié)果表明： 流動(dòng)沸騰換熱系數(shù)同時(shí)受工質(zhì)質(zhì)量流速、工質(zhì)蒸發(fā)溫度及加熱溫度的影響。在相同的蒸發(fā)溫度及加熱溫度下，流動(dòng)沸騰換熱系數(shù)隨工質(zhì)質(zhì)量流速的增加而迅速增加；在相同的蒸發(fā)溫度及質(zhì)量流速下，隨著工質(zhì)加熱溫度的增大，流動(dòng)沸騰換熱系數(shù)先較快增加，然后增加逐漸變緩；在相同的加熱溫度和質(zhì)量流速下，隨著工質(zhì)蒸發(fā)溫度的增加，流動(dòng)沸騰換熱系數(shù)逐漸降低。 在以上理論分析和模擬計(jì)算的基礎(chǔ)上，，設(shè)計(jì)和搭建了雙循環(huán)有機(jī)工質(zhì)沸騰換熱特性實(shí)驗(yàn)系統(tǒng)。
[Abstract]:Industry is the most important department of energy consumption in China. China's industrial energy consumption accounts for more than 70% of the total energy consumption, but its energy utilization rate is very low. A large part of industrial energy consumption is converted into industrial waste heat with different carriers and different temperatures. Taking the sintering process of iron and steel industry as an example, about 50% of the heat energy in the sintering process is taken away by the sintering flue gas and cooler exhaust gas, and the sensible heat taken away by the waste gas accounts for more than 20% of the total sintering energy consumption. It can be seen that the efficient and comprehensive utilization of industrial waste heat is an important way to achieve the strategic goal of energy saving and emission reduction in China. Organic Rankine cycle power generation with low boiling point organic working fluid as circulating working fluid is an effective way to utilize medium and low temperature waste heat resources. The measurement of flow boiling heat transfer coefficient of organic working fluid is an important part of organic Rankine cycle power generation system. in this paper, the flow boiling heat transfer characteristics of organic working fluid in tube are simulated and analyzed, and an experimental system for boiling heat transfer characteristics of double cycle organic working fluid is designed and built, which lays a foundation for further experimental study on the heat transfer characteristics of organic working fluid used in organic Rankine cycle power generation at low temperature. In this paper, the basic parameters of gas-liquid two-phase flow and the characteristics of flow boiling heat transfer are analyzed. The basic characteristics of flow boiling heat transfer, such as section gas content, cross section liquid content, mass flow rate, mass gas content, mass flow rate, volume gas content, real vapor phase velocity, vapor phase conversion velocity, slip ratio, sliding velocity, flow pattern of two-phase flow and flow boiling heat transfer area of horizontal tube, are analyzed. Then the flow boiling heat transfer characteristics in organic working fluid tube are studied by numerical analysis. The heat transfer model in organic working fluid tube is established, which includes turbulence model and multiphase flow model. The flow boiling heat transfer characteristics of two typical organic refrigerants R245fa and R123 in horizontal smooth tube were analyzed and calculated by using CFD software. The distribution and variation of temperature field, velocity field, heat transfer coefficient and heat transfer coefficient of R245fa and R123 in horizontal tube were obtained. By changing the inlet boundary conditions, the effects of mass flow rate, evaporation temperature and working fluid heating temperature on boiling heat transfer are simulated. The simulation results show that the flow boiling heat transfer coefficient is affected by the mass flow rate of the working fluid, the evaporation temperature and the heating temperature of the working fluid. At the same evaporation temperature and heating temperature, the flow boiling heat transfer coefficient increases rapidly with the increase of the mass flow rate of the working fluid; at the same evaporation temperature and mass flow rate, the flow boiling heat transfer coefficient increases rapidly at first and then slows down with the increase of the working fluid heating temperature; at the same heating temperature and mass flow rate, the flow boiling heat transfer coefficient decreases gradually with the increase of the working fluid evaporation temperature. On the basis of the above theoretical analysis and simulation calculation, an experimental system for boiling heat transfer characteristics of double cycle organic working fluid is designed and built.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM617

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 冷婷婷;王華;;非共沸工質(zhì)R407C蒸發(fā)過程的數(shù)值分析[J];貴州大學(xué)學(xué)報(bào)(自然科學(xué)版);2010年04期

2 連紅奎;李艷;束光陽子;顧春偉;;我國(guó)工業(yè)余熱回收利用技術(shù)綜述[J];節(jié)能技術(shù);2011年02期

3 Gary J.Zyhowski,Sr. ,Mark W.Spatz ,Samuel Yana Motta ,張社;HFC-245fa性質(zhì)及應(yīng)用綜述[J];家電科技;2003年08期

4 廖志杰;;中國(guó)低碳地?zé)岚l(fā)電的回顧與展望[J];自然雜志;2011年02期

本文編號(hào)：2497643