發(fā)布時間：2018-03-05 20:38

  本文選題：運行特性　切入點：冷卻塔　出處：《華南理工大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：空調(diào)系統(tǒng)節(jié)能運行是公共建筑節(jié)能減排的關(guān)鍵所在，，而冷凍水系統(tǒng)和冷卻水系統(tǒng)的運行性能直接決定了空調(diào)系統(tǒng)的能耗。本文分別對冷卻水系統(tǒng)中冷卻塔和冷凍水系統(tǒng)管網(wǎng)的運行特性進(jìn)行了理論分析及實驗研究，為空調(diào)系統(tǒng)優(yōu)化運行提供參考。 冷卻塔是冷卻水系統(tǒng)中一個重要的設(shè)備，其運行性能將對冷凝器的換熱有直接影響，從而對整個空調(diào)系統(tǒng)的運行效率產(chǎn)生影響。本文在充分考慮回流、蒸發(fā)損失、劉易斯數(shù)和實際填料特性數(shù)的基礎(chǔ)上分別對機(jī)械通風(fēng)橫流塔和逆流塔建立數(shù)學(xué)模型，并對兩種類型塔進(jìn)行了測試驗證。結(jié)果表明，橫流塔出水溫度相對誤差低于3.5%；逆流塔出水溫度相對誤差低于2%，從而驗證了理論模型是準(zhǔn)確可靠的。 分析了劉易斯數(shù)、特性數(shù)修正系數(shù)、飄水和回流對冷卻塔運行的影響。結(jié)果表明，對于大溫差的模擬研究需對劉易斯關(guān)系式進(jìn)行修正，否則，模擬結(jié)果可能和實際結(jié)果相差較大，尤其是出塔空氣干球溫度和出塔空氣相對濕度；實際特性數(shù)與標(biāo)準(zhǔn)工況值偏離越大，對冷卻塔性能影響越大。分析結(jié)果表明填料特性數(shù)修正系數(shù)從1降到0.5，換熱量減少達(dá)到23.5%；而從1降到0.1，換熱量減少高達(dá)74.3%。冷卻塔存在回流會影響冷卻塔的冷卻能力同時會影響周邊人群舒適感。當(dāng)回流率增加到50%時，出水溫度升高2.7°C，換熱量減少40.68%和舒適度指數(shù)變化1.92。 冷凍水系統(tǒng)運行性能直接影響到整個系統(tǒng)的能耗和空調(diào)區(qū)域的舒適性�；趬翰羁刂茖鋬鏊到y(tǒng)管網(wǎng)的靜態(tài)和動態(tài)特性進(jìn)行實驗分析研究。結(jié)果表明，實驗得到冷凍水系統(tǒng)壓差特性和水泵能耗特性與理論所得的結(jié)論較吻合；旁通閥設(shè)定壓差值和控制壓差值的選擇對主機(jī)功率的影響不大卻對水泵功率影響顯著，而且影響壓差控制的穩(wěn)定性和控制精度。當(dāng)控制壓差小于或者稍大于旁通閥設(shè)定壓差值時，管網(wǎng)穩(wěn)定性較好；而當(dāng)控制壓差大于旁通壓差設(shè)定值且相差較大時，管網(wǎng)嚴(yán)重震蕩；當(dāng)控制壓差接近旁通設(shè)定壓差值時，實際壓差接近控制壓差，控制精度較高；而當(dāng)控制壓差偏離旁通閥設(shè)定壓差值時，實際壓差偏離控制壓差，控制精度較差，且控制壓差偏離旁通閥設(shè)定壓差值越大，實際壓差與控制壓差偏差越大，控制精度越差。
[Abstract]:Energy saving operation of air conditioning system is the key to energy saving and emission reduction of public buildings. The operation performance of chilled water system and cooling water system directly determines the energy consumption of air conditioning system. In this paper, the operating characteristics of cooling tower and pipe network in cooling water system are analyzed theoretically and experimentally. Provides the reference for the air conditioning system optimization operation. The cooling tower is an important equipment in the cooling water system. Its operation performance will have a direct effect on the heat transfer of the condenser, thus has an impact on the operation efficiency of the whole air conditioning system. Based on the Lewis number and the actual packing characteristic number, the mathematical models of the mechanical ventilation crossflow tower and the countercurrent tower are established, and the two types of columns are tested and verified. The results show that, The relative error of outlet temperature of cross flow tower is lower than 3.5 and that of counterflow tower is less than 2. The theoretical model is proved to be accurate and reliable. The effects of Lewis number, characteristic number correction coefficient, floating water and reflux on the operation of cooling tower are analyzed. The simulated results may differ greatly from the actual results, especially the dry ball temperature and the relative humidity of the outlet air, and the deviation between the actual characteristics and the standard operating conditions is greater. The results show that the correction coefficient of packing characteristics decreases from 1 to 0.5, and the heat transfer decreases to 23.50.The heat exchange decreases up to 74.3% from 1 to 0.1. The cooling energy of cooling tower is affected by the existence of backflow in the cooling tower. The force also affects the comfort of the surrounding crowd. When the reflux rate increases to 50, The effluent temperature increased by 2.7 擄C, the heat exchange decreased by 40.68% and the comfort index changed by 1.92. The operation performance of the chilled water system directly affects the energy consumption of the whole system and the comfort of the air conditioning area. Based on the pressure difference control, the static and dynamic characteristics of the chilled water system pipe network are studied experimentally. The results show that, The experimental results show that the pressure difference characteristics and pump energy consumption characteristics of the chilled water system are in good agreement with the theoretical results, and that the selection of the pressure-difference value and the control pressure difference value of the bypass valve have little effect on the power of the main engine but have a significant effect on the power of the pump. When the control pressure difference is less than or slightly larger than the set pressure difference value of the bypass valve, the pipe network stability is better, but when the control pressure difference is greater than the set value of the bypass pressure difference and the difference is large, the pipe network is severely shaken. When the control pressure difference is close to the bypass pressure-difference value, the actual pressure difference approaches the control pressure difference, and the control accuracy is higher, but when the control pressure difference deviates from the preset pressure difference value of the bypass valve, the actual pressure difference deviates from the control pressure difference, and the control accuracy is poor. The greater the value of the pressure difference between the control pressure difference and the control pressure difference, the greater the deviation between the actual pressure difference and the control pressure difference, and the worse the control precision.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TB657

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張志剛;王瑋;曾德良;劉吉臻;;冷卻塔出塔水溫的迭代計算方法[J];動力工程學(xué)報;2010年05期

2 張琳;冷卻塔布置中濕空氣回流干擾的計算[J];工業(yè)用水與廢水;2002年03期

3 章立新;黃陳師;陳永勝;張聰;沈艷;;機(jī)械通風(fēng)橫流式冷卻塔組的節(jié)能試驗研究[J];工業(yè)用水與廢水;2009年05期

4 韓琴;劉德有;陳負(fù)山;齊慧卿;焦詩元;;大型冷卻塔熱力計算模型[J];河海大學(xué)學(xué)報(自然科學(xué)版);2009年05期

5 文先太;梁彩華;張小松;;空調(diào)冷卻塔變流量的優(yōu)化研究[J];流體機(jī)械;2009年11期

6 李楊;魏星;;薄膜式機(jī)械通風(fēng)冷卻塔的性能優(yōu)化[J];流體機(jī)械;2010年10期

7 孫一堅;空調(diào)水系統(tǒng)變流量節(jié)能控制(續(xù)1):水流量變化對空調(diào)系統(tǒng)運行的影響[J];暖通空調(diào);2004年07期

8 孟華,龍惟定,王盛衛(wèi) ,張恩澤;適于系統(tǒng)仿真的表冷器模型及其實驗驗證[J];暖通空調(diào);2004年08期

9 孫一堅,潘尤貴;空調(diào)水系統(tǒng)變流量節(jié)能控制(續(xù)2):變頻調(diào)速水泵的合理應(yīng)用[J];暖通空調(diào);2005年10期

10 沈翔;王建民;;也談空調(diào)冷熱水循環(huán)泵變頻節(jié)能問題——兼論《空調(diào)變頻水泵節(jié)能問題探討》和《空調(diào)冷熱水循環(huán)泵變轉(zhuǎn)速節(jié)能控制方法》兩文[J];暖通空調(diào);2006年04期

本文編號：1571789