本文選題：土壤源熱泵 + 可再生能源��； 參考：《重慶大學(xué)》2015年博士論文

【摘要】：土壤源熱泵系統(tǒng)是以巖土體為低溫?zé)嵩?由熱泵機(jī)組、地埋管換熱系統(tǒng)、建筑物內(nèi)系統(tǒng)組成的空調(diào)系統(tǒng)。它充分利用低品位地?zé)崮茉?可夏季供冷、冬季供熱,高效節(jié)能,被稱為21世紀(jì)非常具有發(fā)展前途的可再生能源應(yīng)用空調(diào)技術(shù)。地埋管換熱器是用于傳熱介質(zhì)與巖土體在地埋管換熱系統(tǒng)中進(jìn)行換熱的載體,其換熱性能是制約土壤源熱泵技術(shù)發(fā)展關(guān)鍵因素之一。全面認(rèn)識和掌握地埋管換熱器的熱量傳遞過程,可以正確指導(dǎo)地埋管換熱器的設(shè)計(jì),提高換熱效率,保證系統(tǒng)安全可靠運(yùn)行,降低系統(tǒng)能耗,有利于土壤源熱泵技術(shù)的良性發(fā)展和應(yīng)用。本文依托重慶某土壤源熱泵工程,針對實(shí)際工程中地埋管換熱器所處巖土體由多種地質(zhì)層組成且存在地下水滲流的情況,采用理論分析和現(xiàn)場實(shí)測相結(jié)合的方法,對地埋管換熱器的換熱性能開展研究。論文綜合考慮地質(zhì)分層和地下水滲流等因素,建立豎直雙U型地埋管分層換熱模型;根據(jù)工程熱響應(yīng)測試及實(shí)際運(yùn)行結(jié)果,通過理論推導(dǎo),求解出各分層的綜合熱物性參數(shù);并以此熱物性參數(shù)為邊界條件,利用現(xiàn)代CFD技術(shù)進(jìn)行動態(tài)數(shù)值模擬,對所建模型進(jìn)行流速、回填料、埋深等因素,冬夏季取、排熱等工況全面對比分析,驗(yàn)證其計(jì)算精度及可靠性。并將常規(guī)均勻換熱模型和本文研究的分層換熱模型計(jì)算結(jié)果分別與工程實(shí)際運(yùn)行數(shù)據(jù)進(jìn)行了對比。利用驗(yàn)證后的分層換熱模型分析流速、回填料、埋深、井間距等因素對地埋管換熱器的影響,并合理確定各因素水平。以正交試驗(yàn)理論為基礎(chǔ),合理設(shè)置模擬試驗(yàn)方案,分析地埋管換熱器各種條件下的換熱特性及其影響因素的顯著性。最后基于地埋管分層換熱模型,分析其在工程中的應(yīng)用方法,提出應(yīng)用于工程的簡化分層換熱模型。實(shí)測研究表明,土壤各分層內(nèi)熱物性參數(shù)存在一定的差異,即使是同一地質(zhì)層也存在差異。該實(shí)驗(yàn)工程實(shí)測各分層熱阻在0.1344~0.1717(m·K)/W之間變化,變化幅度達(dá)20%以上,因此模型分層具有必要性。實(shí)測及模擬研究表明,在同一地質(zhì)層巖土導(dǎo)熱熱阻與地下水滲流流向、流速及地下孔隙率有關(guān),結(jié)合地質(zhì)分層及測點(diǎn)分布對地埋管換熱器模型進(jìn)行豎向分層具有合理性。以實(shí)際工程實(shí)測數(shù)據(jù)和不同流速、埋深及回填料導(dǎo)熱系數(shù)以及季節(jié)取、排熱過程的模擬結(jié)果對比驗(yàn)證,發(fā)現(xiàn)各驗(yàn)證工況下,各深度、各時(shí)刻管壁溫度模擬值與實(shí)測值最大平均相對誤差僅為1.82%。分層換熱模型綜合考慮地質(zhì)分層、地下水滲流等因素,更加合理完善、可靠,且計(jì)算精度高。實(shí)測及模擬研究還表明,常規(guī)均勻換熱模型與實(shí)測值之間存在較大差距,常規(guī)均勻模型單位井深換熱量與實(shí)測值誤差為7.83%,分層換熱模型單位井深換熱量與實(shí)測值誤差為1.56%,分層換熱模型與實(shí)測值更接近。通過模擬,發(fā)現(xiàn)地埋管換熱的影響因素中,流速的顯著性最大,其次為埋深和井間距,回填料導(dǎo)熱系數(shù)為非顯著性因素。研究表明,根據(jù)熱響應(yīng)測試原理,在工程應(yīng)用中采用簡化分層換熱模型進(jìn)行熱響應(yīng)測試及分析,可更準(zhǔn)確分析土壤的熱物性參數(shù)。用于設(shè)計(jì)計(jì)算,可更準(zhǔn)確地求解合理的單井埋深及埋管總長度,方法可靠,簡單可行。分層換熱模型在工程中具有較好的應(yīng)用前景。
[Abstract]:Soil source heat pump system is an air conditioning system composed of heat pump unit, buried pipe heat exchange system and inner building system. It makes full use of low grade geothermal energy, can supply cold in summer, heating in winter, high efficiency and energy saving. It is called as a very promising renewable energy application technology in twenty-first Century. Heat exchanger is used as the carrier for heat transfer medium and rock mass in the heat transfer system of buried pipe. The heat transfer performance is one of the key factors restricting the development of soil source heat pump. The overall understanding and mastery of the heat transfer process of the buried pipe heat exchanger can correctly guide the design of the heat exchanger of the buried pipe, improve the heat transfer efficiency and ensure the system safety. Fully reliable operation, reducing the energy consumption of the system, is beneficial to the benign development and application of the soil source heat pump technology. Based on a soil source heat pump project in Chongqing, this paper combines the theoretical analysis and field measurement for the rock and soil mass of the buried pipe heat exchanger in the actual project. The heat transfer performance of the buried pipe heat exchanger is studied. The paper takes into consideration the factors of geological stratification and groundwater seepage, and establishes a vertical double U type buried pipe stratified heat transfer model. According to the engineering thermal response test and the actual operation results, the thermal physical parameters of each layer are solved by theoretical derivation, and the thermal physical parameters are the boundary. Conditions, using the modern CFD technology to carry out dynamic numerical simulation, carry out the flow velocity, back filling, buried depth and other factors of the model, compare and analyze the working conditions such as winter and summer, heat discharge and so on, to verify the calculation accuracy and reliability. And the conventional uniform heat transfer model and the calculated results of the sub layer heat transfer model in this paper are separately from the actual operation data of the project. The effect of flow rate, back filling, depth, well spacing and other factors on the heat exchanger of buried pipe is analyzed and the level of various factors is rationally determined. Based on the orthogonal test theory, the simulation test scheme is set up reasonably, and the heat transfer characteristics and its influencing factors under the various conditions of the buried pipe heat exchanger are analyzed. In the end, based on the stratified heat transfer model of buried pipe, the application method in the engineering is analyzed, and a simplified stratified heat transfer model applied to the engineering is put forward. The experimental study shows that there is a certain difference in the thermal property parameters in the soil layers, even in the same geological layer. The experimental engineering measured the thermal resistance of each layer in 0.1344~0.1 The variation of 717 (M. K) /W is more than 20%, so the model stratification is necessary. The measurement and simulation study shows that the vertical stratification of the buried pipe heat exchanger model in the same geological layer is reasonable with the geological stratification and the measurement point distribution. According to the actual engineering data and different velocity, the thermal conductivity of the buried depth and the backfill and the simulation results of the heat transfer process, it is found that the maximum average relative error of the depth and the maximum average temperature of the tube wall temperature and the measured value is only the 1.82%. layer heat transfer model, which considers the geological stratification and the groundwater seepage. Flow and other factors are more reasonable, reliable, and with high calculation precision. The measurement and simulation study also shows that there is a big gap between the conventional uniform heat transfer model and the measured value. The error of the unit well depth change and the measured value of the unit well depth of the conventional uniform model is 7.83%, and the depth of the unit well depth change and the measured value is 1.56%, and the stratified heat transfer die is a stratified heat transfer model. The model is closer to the measured value. Through the simulation, it is found that the velocity is the most significant in the influence factors of the buried pipe heat transfer, followed by the buried depth and the well spacing, and the thermal conductivity of the backfill is not significant. The study shows that the thermal response test and analysis are carried out in the engineering application by the simplified stratified heat transfer model in the engineering application. It is more accurate to analyze the thermal physical parameters of soil. It is more accurate to solve the reasonable buried depth of single well and the total length of buried pipe in the design and calculation. The method is reliable and simple and feasible. The model of stratified heat transfer has a good application prospect in the project.
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TU831

【引證文獻(xiàn)】

相關(guān)會議論文 前1條

1 ;首屆中國地源熱泵技術(shù)城市級應(yīng)用高層論壇回顧[A];第二屆中國地源熱泵技術(shù)城市級應(yīng)用高層論壇論文集[C];2007年

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本文編號：1972208