本文選題：地源熱泵 + 換熱熱阻　； 參考：《湖南大學(xué)》2015年碩士論文

【摘要】：現(xiàn)如今,能源短缺已成為社會的首要問題之一,地源熱泵以其優(yōu)越的節(jié)能環(huán)保的特性得到了越來越多的應(yīng)用。因此,對于地源熱泵的性能研究也是人們首要關(guān)心的問題之一。而地下?lián)Q熱器是地源熱泵換熱的重要部件,直接影響到地源熱泵整個系統(tǒng)的運行性能。由此,本文主要從三個不同的角度對地源熱泵地下?lián)Q熱器的換熱性能進(jìn)行研究。換熱熱阻直接影響到地源熱泵地下?lián)Q熱器的換熱性能,因此本文利用地源熱泵單U地埋管二維換熱模型,以鉆孔內(nèi)的換熱熱阻為目標(biāo)函數(shù),以回填材料導(dǎo)熱系數(shù)、兩埋管間距及管內(nèi)水流速等參數(shù)為優(yōu)化變量,利用遺傳算法,對各參數(shù)同時變化時進(jìn)行了目標(biāo)函數(shù)優(yōu)化,并分析了各參數(shù)對熱阻性能影響。研究得出在鉆孔孔徑和埋管管徑組合一定的情況下,當(dāng)回填材料導(dǎo)熱系數(shù)、兩埋管間距及管內(nèi)流體流速均為最大值時,鉆孔內(nèi)換熱熱阻達(dá)到最優(yōu)。用單U、雙U地埋管地源熱泵準(zhǔn)三維換熱模型,以能效系數(shù)及嗾效率為評價指標(biāo),通過Matlab自編程序,計算出流體出口溫度,并利用流體進(jìn)口溫度、流體質(zhì)量流量、埋管深度等分析了這些影響參數(shù)對單U及雙U埋管換熱器的換熱性能的影響。研究得出雙U地埋管換熱器的能效系數(shù)及嗾效率均高于單U地埋管換熱器。利用FLUENT數(shù)值模擬軟件建立起一個二維有限體積的模型,瞬態(tài)模擬了單U埋管換熱器管壁不同時刻的溫度響應(yīng)。單U埋管換熱器的兩個支管的溫度響應(yīng)由地埋側(cè)的傳熱平衡方程進(jìn)行求得,并通過FLUENT中的UDF編寫程序得以實現(xiàn)。研究得出當(dāng)使用下降管與上升管換熱量所占的比例分別為60%與40%時來分析地下?lián)Q熱時更接近實際情況。不同的連續(xù)運行時間對地溫的恢復(fù)有著不同的影響,連續(xù)運行的時間越長,地溫恢復(fù)到原始溫度所需要的時間也就越長。
[Abstract]:Nowadays, energy shortage has become one of the most important problems in society. Ground source heat pump (GSHP) has been applied more and more because of its superior energy saving and environmental protection characteristics.Therefore, the performance of ground source heat pump is also one of the most important concerns.The ground heat exchanger is an important part of the ground source heat pump, which directly affects the operation performance of the whole system of the ground source heat pump.Therefore, this paper mainly studies the heat transfer performance of ground source heat exchanger from three different angles.Heat transfer resistance directly affects the heat transfer performance of ground source heat pump (GSHP) ground heat exchanger. In this paper, the heat transfer coefficient of backfill material is taken as the objective function and the heat transfer resistance in borehole is taken as the objective function by using the two-dimensional heat transfer model of ground source heat pump (GSHP) single U buried tube.The parameters such as the distance between two buried pipes and the velocity of water in the pipe are optimized by genetic algorithm. The objective function is optimized when each parameter changes simultaneously and the influence of each parameter on the thermal resistance performance is analyzed.The results show that the heat transfer resistance of the borehole is optimal when the heat conductivity of the backfill material, the distance between the two buried pipes and the flow velocity in the pipe are the maximum when the combination of the bore hole aperture and the buried pipe diameter is certain.The quasi three dimensional heat transfer model of single U and double U ground source heat pump is used. Taking the energy efficiency coefficient and baiting efficiency as the evaluation index, the outlet temperature of the fluid is calculated by Matlab program, and the inlet temperature of the fluid and the mass flow rate of the fluid are used.The influence of these parameters on the heat transfer performance of single U and double U buried tube heat exchangers was analyzed.The energy efficiency coefficient and efficiency of double U buried tube heat exchanger are higher than that of single U ground tube heat exchanger.A two-dimensional finite volume model was established by using FLUENT software, and the temperature response of the tube wall of a single U-tube heat exchanger at different times was transient simulated.The temperature response of two branch tubes in a single U tube heat exchanger is obtained from the heat transfer equilibrium equation of the buried side and realized by the UDF program in FLUENT.The results show that when the proportion of heat transfer between descending tube and rising tube is 60% and 40% respectively, the underground heat transfer is closer to the actual situation.Different continuous operation time has different influence on the ground temperature recovery. The longer the continuous operation time, the longer it takes to recover the ground temperature to the original temperature.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU83

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 張泉;杜亞星;張林峰;周明衛(wèi);;基于遺傳算法的單U地源熱泵鉆孔內(nèi)熱阻研究[J];湖南大學(xué)學(xué)報(自然科學(xué)版);2014年09期

2 楊昌智;黃兵;;U型管換熱性能影響因素研究[J];湖南大學(xué)學(xué)報(自然科學(xué)版);2009年S2期

3 胡平放;康龍;江章寧;於仲義;孫啟明;徐菱虹;;地源熱泵U型埋管換熱影響因素的數(shù)值模擬與分析[J];流體機械;2009年03期

4 付文彪;蔣綠林;紀(jì)洪林;張曄;;地源熱泵設(shè)計中兩個重要參數(shù)的實驗研究[J];暖通空調(diào);2009年02期

5 唐志偉;金楠;閆桂蘭;;地源熱泵地中換熱器的非穩(wěn)態(tài)傳熱數(shù)值研究[J];可再生能源;2008年01期

6 ;Efficiency of Vertical Geothermal Heat Exchangers in the Ground Source Heat Pump System[J];Journal of Thermal Science;2003年01期

7 曾和義,方肇洪;雙U型埋管地?zé)釗Q熱器的傳熱模型[J];山東建筑工程學(xué)院學(xué)報;2003年01期

8 方肇洪 ,刁乃仁 ,崔萍;Discontinuous Operation of Geothermal Heat Exchangers[J];Tsinghua Science and Technology;2002年02期

9 柳曉雷,王德林,方肇洪;垂直埋管地源熱泵的圓柱面?zhèn)鳠崮Ｐ图昂喕嬎鉡J];山東建筑工程學(xué)院學(xué)報;2001年01期

相關(guān)博士學(xué)位論文 前1條

1 於仲義;土壤源熱泵垂直地埋管換熱器傳熱特性研究[D];華中科技大學(xué);2008年

，

本文編號：1762453