本文選題：有機(jī)朗肯循環(huán)　切入點(diǎn)：流動(dòng)壓降　出處：《湘潭大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：有機(jī)朗肯循環(huán)(Organic Rankine Cycle,簡(jiǎn)稱ORC)發(fā)電技術(shù)是一種高效低品位余熱回收技術(shù),具有結(jié)構(gòu)簡(jiǎn)單、熱效率高,蒸發(fā)壓力相對(duì)較低等優(yōu)點(diǎn)。本文針對(duì)ORC發(fā)電技術(shù),在考慮流動(dòng)壓降下分析運(yùn)行參數(shù)對(duì)系統(tǒng)整體性能的影響,開(kāi)展蒸發(fā)器運(yùn)行參數(shù)和結(jié)構(gòu)參數(shù)的多目標(biāo)優(yōu)化,該研究對(duì)ORC發(fā)電技術(shù)的工業(yè)應(yīng)用有一定的指導(dǎo)作用。具體內(nèi)容和結(jié)論如下:1)建立ORC系統(tǒng)流動(dòng)壓降計(jì)算模型與系統(tǒng)熱力分析模型,根據(jù)給定的初始參數(shù)對(duì)系統(tǒng)蒸發(fā)器和冷凝器進(jìn)行設(shè)計(jì),得到翅片管式蒸發(fā)器的管長(zhǎng)為159.6m、換熱面積為46.26m~2,板式冷凝器的板片數(shù)為57、換熱面積為27.58m~2;依據(jù)ORC系統(tǒng)工質(zhì)篩選原則,選取R245fa、R123、R600a、R141b、R134a和R236ea等六種常用循環(huán)工質(zhì)。在此基礎(chǔ)上,利用文獻(xiàn)結(jié)果驗(yàn)證了模型的可靠性。2)研究運(yùn)行參數(shù)(蒸發(fā)壓力、過(guò)熱度、節(jié)點(diǎn)溫差)和熱源溫度對(duì)流動(dòng)壓降的影響規(guī)律,并以凈輸出功、熱效率、?效率、熱回收率、不可逆損失為評(píng)價(jià)指標(biāo),對(duì)比分析流動(dòng)壓降對(duì)ORC系統(tǒng)性能的影響規(guī)律。結(jié)果表明:ORC系統(tǒng)的流動(dòng)壓降主要由蒸發(fā)器壓降組成,且蒸發(fā)壓力是影響系統(tǒng)壓降的主要因素�？紤]流動(dòng)壓降下,蒸發(fā)壓力低于0.8MPa會(huì)導(dǎo)致系統(tǒng)各性能指標(biāo)的降幅增大。對(duì)于干工質(zhì),節(jié)點(diǎn)溫差與過(guò)熱度對(duì)流動(dòng)壓降的影響較小,不同節(jié)點(diǎn)溫差下流動(dòng)壓降對(duì)系統(tǒng)性能的影響小于10%;流動(dòng)壓降隨著熱源溫度的升高而增大。此外,工質(zhì)是影響系統(tǒng)流動(dòng)壓降與系統(tǒng)性能的重要因素,幾種工質(zhì)中,R141b和R245fa為最佳工質(zhì)。3)以O(shè)RC系統(tǒng)的流動(dòng)壓降、凈輸出功、熱效率和熱回收率為優(yōu)化目標(biāo),以蒸發(fā)器的熱力參數(shù)(蒸發(fā)壓力、過(guò)熱度、節(jié)點(diǎn)溫差)、蒸發(fā)器結(jié)構(gòu)參數(shù)(換熱管的管長(zhǎng)、單排管子數(shù)、翅片高度、翅片厚度和翅片間距)為設(shè)計(jì)變量,采用模擬退火優(yōu)化算法對(duì)ORC系統(tǒng)蒸發(fā)器進(jìn)行優(yōu)化設(shè)計(jì),分析蒸發(fā)器熱力參數(shù)和結(jié)構(gòu)參數(shù)對(duì)ORC系統(tǒng)性能的影響規(guī)律。結(jié)果表明:系統(tǒng)各性能指標(biāo)之間存在博弈與對(duì)立現(xiàn)象,蒸發(fā)器熱力參數(shù)中蒸發(fā)壓力對(duì)目標(biāo)函數(shù)值的影響最大,優(yōu)化條件下R245fa的最佳蒸發(fā)壓力為2.5MPa;蒸發(fā)器結(jié)構(gòu)參數(shù)中,翅片結(jié)構(gòu)是影響系統(tǒng)熱力性能的重要因素,而換熱管布置方式對(duì)系統(tǒng)熱力性能的影響基本可以忽略。對(duì)于R245fa,優(yōu)化后的翅片結(jié)構(gòu)參數(shù)為翅片高度34mm、翅片厚度7.3mm、翅片間距3.5mm。
[Abstract]:Organic Rankine cycle (ORC) power generation technology is an efficient and low grade waste heat recovery technology, which has the advantages of simple structure, high thermal efficiency and relatively low evaporation pressure. Considering the flow pressure drop, the influence of operation parameters on the overall performance of the system is analyzed, and the multi-objective optimization of evaporator operating parameters and structural parameters is carried out. The research can be used to guide the industrial application of ORC power generation technology. The specific contents and conclusions are as follows: 1) the flow pressure drop calculation model of ORC system and the thermodynamic analysis model of ORC system are established. According to the design of system evaporator and condenser based on the given initial parameters, the tube length of finned tube evaporator is 159.6 m, the heat transfer area is 46.26 mm2, the plate number of plate condenser is 57, and the heat transfer area is 27.58 m2.According to the working medium screening principle of ORC system, Six commonly used circulating working fluids, R245faa R125faan R123AU R141bP134a and R236ea, are selected. On this basis, the reliability of the model is verified by using the results of literature. The effects of operating parameters (evaporation pressure, superheat degree, node temperature difference) and heat source temperature on the flow pressure drop are studied. And with the net output work, thermal efficiency? Efficiency, thermal recovery and irreversible loss are the evaluation indexes. The effect of flow pressure drop on the performance of ORC system is compared and analyzed. The results show that the flow pressure drop of ORC system is mainly composed of evaporator pressure drop. The evaporation pressure is the main factor affecting the pressure drop of the system. Considering the flow pressure drop, when the evaporation pressure is lower than 0.8 MPA, the decrease of the system performance will increase. For the dry working fluid, the effect of node temperature difference and superheat on the flow pressure drop is small. The effect of flow pressure drop on system performance is less than 10 under different node temperature differences, and the flow pressure drop increases with the increase of heat source temperature. In addition, the working fluid is an important factor affecting the system flow pressure drop and system performance. R141b and R245fa are the best working medium. 3) with the flow pressure drop, net output work, thermal efficiency and thermal recovery of ORC system as the optimization objectives, the thermodynamic parameters of evaporator (evaporation pressure, superheat degree, etc. The parameters of evaporator structure (tube length, pipe number, fin height, fin thickness and fin spacing) are used as design variables. Simulated annealing optimization algorithm is used to optimize the design of evaporator in ORC system. The influence of thermodynamic parameters and structural parameters of evaporator on the performance of ORC system is analyzed. The results show that there is a game and opposition phenomenon among the performance indexes of the system, and the evaporation pressure has the greatest influence on the objective function value of the thermodynamic parameters of the evaporator. The optimum evaporation pressure of R245fa is 2.5 MPA, and the fin structure is an important factor affecting the thermodynamic performance of the evaporator. For R245 faa, the optimized fin structure parameters are fin height 34mm, fin thickness 7.3mm, fin spacing 3.5mm.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM617

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王華榮;徐進(jìn)良;;采用BP-GA算法的有機(jī)朗肯循環(huán)多目標(biāo)優(yōu)化[J];中國(guó)電機(jī)工程學(xué)報(bào);2016年12期

2 王慧;馬新靈;孟祥睿;魏新利;;工質(zhì)流量對(duì)ORC低溫余熱發(fā)電系統(tǒng)性能的影響[J];化工學(xué)報(bào);2015年10期

3 魏新利;閆艷偉;馬新靈;孟祥睿;李明輝;;有機(jī)朗肯循環(huán)系統(tǒng)蒸發(fā)器的性能研究[J];鄭州大學(xué)學(xué)報(bào)(工學(xué)版);2015年04期

4 鄧立生;黃宏宇;何兆紅;z錒夂，

本文編號(hào)：1608399