【摘要】：地埋管換熱器作為土壤源熱泵系統(tǒng)最大的換熱部件，它的換熱性能直接影響到整個土壤源熱泵系統(tǒng)的能效特性。而辦公建筑間歇性使用特點，以及土壤源熱泵系統(tǒng)的使用受土壤吸放熱平衡所限制，使得土壤源熱泵需要添加其它輔助散熱設(shè)備，這又決定了辦公建筑冷、熱負荷及地埋管換熱器負荷分配特性，最終影響到土壤源多源復(fù)合熱泵系統(tǒng)的能效性能。本課題就影響土壤源多源復(fù)合熱泵系統(tǒng)能效特性的原因進行深入研究，提出能效較高的新型土壤源多源復(fù)合熱泵系統(tǒng)。 本課題根據(jù)地埋管換熱器傳熱機理建立計算模型，以地埋管換熱器鉆孔井壁為界，將地埋管換熱器分為鉆孔內(nèi)部模型與鉆孔外部模型，鉆孔內(nèi)部采用解析計算模型，鉆孔外部采用數(shù)值計算模型。對鉆孔外部模型進行對稱性分析，簡化了鉆孔外部計算模型，減少了所要計算的次數(shù)。 以都市之門2012年夏季工況土壤源熱泵實測放熱量作為鉆孔外部編程計算的輸入值，采用MATLAB軟件對所建立的模型進行編程計算，將地埋管換熱器出口溫度編程計算值與實測值進行比較，剔除由于開機時刻不穩(wěn)定運行導(dǎo)致的誤差之后，平均誤差為1.7%，誤差均在5%以內(nèi)，驗證了所建立地埋管換熱器模型的正確性。 根據(jù)西安典型氣象年數(shù)據(jù)對某待建辦公項目采用DeST軟件進行全年動態(tài)負荷計算，在基本滿足地埋管換熱器吸放熱平衡的條件下進行負荷分配，通過對地埋管換熱器全年8760個小時的編程計算，得到全年運行后土壤平均溫度僅升高了0.19℃，保證了地埋管換熱器的換熱性能。 辦公建筑間歇運行對改善地埋管換熱器的換熱效果起到了重要作用，地埋管換熱器出口溫度在冬/夏工況都沒有出現(xiàn)低溫/高溫報警，系統(tǒng)安全性能高。停機11個小時后，冬"夏季工況，井壁溫度分別修復(fù)了2.65"2.16℃。無論是夏季工況還是冬季工況，運行一個周期24小時，土壤溫度場僅升高或降低0.02℃，，次日整個土壤溫度與當日溫度基本持平。 本文提出了土壤源與污水源雙源復(fù)合的創(chuàng)新型熱泵系統(tǒng)，同時就該熱泵系統(tǒng)原理進行了說明。并且得到：冬季工況，土壤源與污水源雙源復(fù)合熱泵系統(tǒng)較傳統(tǒng)空調(diào)供暖系統(tǒng)節(jié)能30%。夏季工況，土壤源與污水源雙源復(fù)合熱泵系統(tǒng)較傳統(tǒng)冷卻塔系統(tǒng)節(jié)能11.9%；較土壤源+冷卻塔系統(tǒng)節(jié)能9.5%。為辦公建筑空調(diào)系統(tǒng)的設(shè)計可以提供一定的參考。
[Abstract]:As the largest heat transfer component of the ground-source heat pump system, the heat transfer performance of the ground heat exchanger directly affects the energy efficiency characteristics of the whole ground-source heat pump system. However, the intermittent use characteristics of office buildings and the use of ground-source heat pump system are limited by the equilibrium of soil heat absorption and heat release, which makes the ground-source heat pump need to add other auxiliary heat dissipation equipment, which determines the cooling of office buildings. Heat load and load distribution characteristics of underground heat exchanger will affect the energy efficiency of multi-source heat pump system. In this paper, the causes of affecting the energy efficiency characteristics of the ground-source multisource heat pump system are studied, and a new type of ground-source multi-source heat pump system with high energy efficiency is proposed. According to the heat transfer mechanism of the underground tube heat exchanger, the paper establishes the calculation model. Taking the borehole wall of the ground buried tube heat exchanger as the boundary, the ground buried tube heat exchanger is divided into the borehole internal model and the borehole external model, and the analytic calculation model is used in the borehole interior. The numerical calculation model is used for the outside of the borehole. The symmetry analysis of the borehole external model simplifies the borehole external calculation model and reduces the number of times to be calculated. Taking the measured heat emission from ground-source heat pump in the summer of 2012 as the input value of the external programming calculation of borehole, the model was programmed by MATLAB software. By comparing the calculated value of the outlet temperature of ground buried tube heat exchanger with the measured value, the average error is 1.7, and the error is less than 5% after eliminating the error caused by unstable operation at the start time. The correctness of the model is verified. According to the typical meteorological data of Xi'an, the DeST software is used to calculate the annual dynamic load of an office project to be built, and the load distribution is carried out under the condition of basically satisfying the heat balance of heat absorption and discharge of the underground tube heat exchanger. By programming 8760 hours a year, it is found that the average temperature of soil is only increased by 0.19 鈩

本文編號：2196316