發(fā)布時間：2018-07-05 01:10

  本文選題：有機朗肯循環(huán) + 多級蒸發(fā)　； 參考：《天津大學》2014年博士論文

【摘要】：目前，我國能源供需缺口巨大，供需矛盾尖銳，長期以來以煤為主的結構對環(huán)境造成了嚴重影響。實現(xiàn)經濟與資源、環(huán)境協(xié)調發(fā)展最終只有依靠可再生能源。我國地熱資源豐富，地熱發(fā)電投資小運行穩(wěn)定，有機朗肯循環(huán)（Organic RankineCycle, ORC）技術降低了地熱發(fā)電的利用溫度，增加了地熱發(fā)電資源總量。 本文著眼于90-120℃熱水型地熱資源，針對中低溫地熱發(fā)電循環(huán)效率較低的問題，基于回熱有機朗肯循環(huán)（Regenerative Organic Rankine Cycle, RORC），提出了并聯(lián)式（Parallel Double-evaporator Regenerative Organic Rankine Cycle,PDRORC）和串聯(lián)式雙級蒸發(fā)回熱有機朗肯循環(huán)（Series Double-evaporatorRegenerative Organic Rankine Cycle, SDRORC），采用熱力學第一定律分析法、火用分析法、熵分析法與火積分析法相結合的方法建立了RORC、SDRORC和PDRORC理論優(yōu)化模型，并開展了系統(tǒng)形式和循環(huán)參數(shù)優(yōu)化分析和對比研究；以RORC為基礎，對25種純工質、8種二元和11種三元非共沸混合工質的發(fā)電性能進行了評價研究；并開展了系統(tǒng)關鍵部件性能和系統(tǒng)發(fā)電性能實驗研究，重點研究了工質熱力學性質及其充注量對系統(tǒng)性能的影響；對高含水期油田伴生地熱聯(lián)產系統(tǒng)的技術經濟性進行了研究。主要結論如下： （1）火用分析和熵分析分別從系統(tǒng)做功能力和不可逆性角度進行分析，而火積分析則是從傳熱角度進行分析，盡管三種方法的研究視角不同，但在ORC的熱力學優(yōu)化方面，結果均具有一致性。 （2）RORC：火積損失率正比于凈發(fā)電功率，最大凈發(fā)電功率對應于熵產率和火積耗散率變化率轉折點。PDRORC：凈發(fā)電功率正比于火積損失率、熱效率和火用效率，但是反比于熵產率。SDRORC：凈發(fā)電功率、熱效率、火用效率和火積損失率之間存在對應關系，最大凈發(fā)電功率對應于熵產率下降區(qū)間內的最小值。 （3）RORC發(fā)電性能的改善程度取決于回熱器效率，以全生命周期內收益最大化為原則，實際工程中回熱器效率推薦值約為60%。SDRORC與PDRORC的發(fā)電性能均優(yōu)于RORC，但SDRORC改善程度更高，隨著地熱水進出口溫差的增大，SDRORC系統(tǒng)優(yōu)勢更加明顯。 （4）二元非共沸混合工質R365mfc/R245fa、 isopentane/R245fa、neopentane/R245fa、isohexane/R245fa和pentane/R245fa較優(yōu)；三元非共沸混合工質R245fa/pentane/isohexane和R245fa/isopentaneiso/isohexane的發(fā)電性能較優(yōu)。 （5）在額定膨脹比時，渦旋式膨脹機的等熵效率最高；工質傳熱系數(shù)正比于充注量，工質泵出口壓力、工質流量、蒸發(fā)器熱負荷和系統(tǒng)發(fā)電功率與熱源入口溫度之間存在正比關系；工質最佳充注量與評價指標有關，以熱效率為評價指標時，R123、R245fa和R245/Isopentane為混合工質所對應的無量綱體積比（Dimensionless Volume Ratio, DVR）分別為0.38、0.38和0.41。 （6）熱源與工質直接換熱方式改善了發(fā)電性能；設置回熱器和預熱器也在一定程度上提高了發(fā)電性能�！半姛嵊汀贝�(lián)聯(lián)產系統(tǒng)適用于地熱水入口溫度高而維溫伴熱地熱水入口溫度低的場合，而并聯(lián)系統(tǒng)則恰好相反；地熱尾水取代燃油鍋爐每年可以節(jié)省約8160噸原油，，同時還可減排大量污染物。 （7）吸收式制冷可以作為ORC的輔助冷源，也可以滿足約12000m2的住宅建筑的夏季冷需求。多聯(lián)產系統(tǒng)可以滿足258000m2的住宅建筑的冬季供熱需求和47300人的夏季生活熱水供應；聯(lián)產系統(tǒng)中原油的收益超過了74%，而發(fā)電的收益盡管很少，但地熱發(fā)電對于緩解我國的能源供需矛盾具有一定的作用；整個系統(tǒng)的回收期不足4年，油田地熱聯(lián)產系統(tǒng)值得大力推廣應用。
[Abstract]:At present, the gap between supply and demand of energy is huge, the contradiction between supply and demand is sharp, and the coal based structure has a serious impact on the environment for a long time. The realization of the economy and resources and the coordinated development of the environment ultimately depend on the renewable energy. Our geothermal resources are rich, the small transportation line of geothermal power generation is stable, and the Organic RankineCycle, ORC Technology has reduced the utilization temperature of geothermal power and increased the total amount of geothermal power resources.
With a view to the hot water type geothermal resources at 90-120 C, this paper puts forward a parallel type (Parallel Double-evaporator Regenerative Organic Rankine Cycle, PDRORC) and series type double stage evaporative regenerative organic matter, aiming at the low efficiency of the medium and low temperature geothermal power generation cycle, based on the regenerative organic Rankine cycle (Regenerative Organic Rankine Cycle, RORC). Series Double-evaporatorRegenerative Organic Rankine Cycle (SDRORC), using the first law of thermodynamics analysis, exergy analysis, entropy analysis and accretion analysis, the optimization model of RORC, SDRORC and PDRORC is established, and the optimization analysis and comparison of the system forms and cyclic parameters are carried out. On the basis of RORC, the generation performance of 25 kinds of pure refrigerants, 8 kinds of two yuan and 11 three non azeotropic mixtures were evaluated, and the performance of key components and the experimental study on the system generation performance were carried out. The effects of the thermodynamic properties and the filling amount on the performance of the system were studied. The technology and economy of the thermal cogeneration system are studied. The main conclusions are as follows:
(1) the exergy analysis and entropy analysis are analyzed from the angle of work ability and irreversibility respectively, and the analysis of the accretion is analyzed from the angle of heat transfer. Although the research perspective of the three methods is different, the results of the thermodynamic optimization of ORC are all consistent.
(2) RORC: the accretion loss rate is proportional to the net power, the maximum net generating power corresponds to the entropy yield and the turning point of the change rate of the accretion dissipation rate.PDRORC: the net generating power is proportional to the accretion loss rate, the thermal efficiency and the exergy efficiency, but the inverse ratio of the entropy yield.SDRORC: the net generating power, the thermal efficiency, the exergy efficiency and the accretion loss rate. In the corresponding relationship, the maximum net power generation corresponds to the minimum value of the entropy production decline interval.
(3) the improvement of the performance of RORC power generation depends on the efficiency of the regenerator, the principle of maximizing the profit in the whole life cycle. In actual engineering, the performance of the regenerator efficiency of 60%.SDRORC and PDRORC is better than that of RORC, but the improvement of SDRORC is higher. With the increase of the temperature difference between the import and export of geothermal water, the advantage of the SDRORC system is more obvious.
(4) two non azeotropic mixtures of R365mfc/R245fa, isopentane/R245fa, neopentane/R245fa, isohexane/R245fa and pentane/R245fa are superior, and three non azeotropic refrigerants, R245fa/pentane/isohexane and R245fa/isopentaneiso/isohexane, have better power generation performance.
(5) at the rated expansion ratio, the isentropic efficiency of the scroll expander is the highest, and the heat transfer coefficient of the working fluid is proportional to the filling amount, the outlet pressure of the working pump, the flow of the working fluid, the heat load of the evaporator and the system power generation power and the inlet temperature of the heat source; the optimum filling quantity of the working material is related to the evaluation index, and the thermal efficiency is the evaluation index. For R123, R245fa and R245/Isopentane, the corresponding Dimensionless Volume Ratio (DVR) corresponding to mixed refrigerants are 0.38,0.38 and 0.41. respectively.
(6) the direct heat transfer between the heat source and the working fluid improves the power generation performance; the regenerator and preheater also improve the power generation performance to a certain extent. The "electric heating oil" series joint production system is suitable for the occasions where the inlet temperature of the geothermal water inlet is high and the temperature with the hot and hot water inlet is low, while the parallel system is just the opposite; the geothermal tail water is replaced by the ignition. Oil boilers can save about 8160 tons of crude oil every year, and they can also reduce the amount of pollutants.
(7) the absorption refrigeration can be used as the auxiliary cooling source of ORC, and can also meet the cold demand of the residential buildings of about 12000m2. The multi production system can meet the heating demand of the 258000m2 residential building in winter and the summer living hot water supply of 47300 people; the revenue of the Zhongyuan oil in the joint production system is more than 74%, but the income of the power generation is few, but the income of the power generation is very few, but Geothermal power generation plays a certain role in alleviating the contradiction of energy supply and demand in China. The recovery period of the whole system is less than 4 years, and the oil field geothermal production system is worth popularizing and applying.
【學位授予單位】：天津大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TM616

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本文編號：2098261