本文關(guān)鍵詞：數(shù)據(jù)中心用泵驅(qū)動(dòng)兩相冷卻回路換熱特性研究　出處：《北京工業(yè)大學(xué)》2015年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 泵驅(qū)動(dòng) 兩相冷卻回路 數(shù)據(jù)中心 自然冷卻 控制策略

【摘要】：能源問題是現(xiàn)代社會(huì)發(fā)展的三大基本問題之一。隨著大數(shù)據(jù)時(shí)代的到來(lái),數(shù)據(jù)中心數(shù)量和能耗迅速上升,其中空調(diào)能耗占總能耗40%左右。在過(guò)渡季節(jié)和冬季,可利用室外自然冷源對(duì)數(shù)據(jù)中心進(jìn)行冷卻,降低空調(diào)能耗。本文設(shè)計(jì)一種泵驅(qū)動(dòng)兩相回路換熱裝置用于數(shù)據(jù)中心自然冷卻,通過(guò)仿真和試驗(yàn)對(duì)其換熱特性進(jìn)行了深入研究,主要內(nèi)容包括:基于工質(zhì)在蒸發(fā)器出口和冷凝器進(jìn)口狀態(tài),歸納出四種循環(huán)模式,過(guò)熱循環(huán)、兩相循環(huán)、過(guò)冷-兩相循環(huán)和過(guò)冷循環(huán),通過(guò)理論和試驗(yàn)發(fā)現(xiàn)兩相循環(huán)為最佳模式。利用傳熱和壓降方程建立泵驅(qū)動(dòng)兩相回路的一維穩(wěn)態(tài)數(shù)學(xué)模型,并分析了各段阻力對(duì)系統(tǒng)循環(huán)和換熱的影響。隨著蒸發(fā)器進(jìn)口到儲(chǔ)液罐進(jìn)口的工質(zhì)流動(dòng)阻力增加,蒸發(fā)器進(jìn)口工質(zhì)過(guò)冷度升高;隨著冷凝器出口到儲(chǔ)液罐進(jìn)口的阻力增加,蒸發(fā)器進(jìn)口和冷凝器出口的工質(zhì)過(guò)冷度均升高;隨著蒸發(fā)器或冷凝器阻力的增大,換熱量先升高后降低。蒸發(fā)器與冷凝器連接管和冷凝器出口到儲(chǔ)液罐進(jìn)口連接管阻力增大,兩器總換熱量逐漸降低,前者阻力對(duì)應(yīng)的換熱衰減率大于后者。在蒸發(fā)器內(nèi),工質(zhì)溫度先升高后降低,當(dāng)工質(zhì)達(dá)到飽和液時(shí),蒸發(fā)器內(nèi)出現(xiàn)溫差窄點(diǎn)和換熱窄點(diǎn)。蒸發(fā)器的換熱量分布主要集中在換熱器的進(jìn)口段和出口段。在冷凝器內(nèi),工質(zhì)溫度逐漸降低,冷凝器內(nèi)微元換熱量逐漸降低。當(dāng)工質(zhì)達(dá)到飽和液時(shí),冷凝器出現(xiàn)溫差拐點(diǎn)和換熱拐點(diǎn)。通過(guò)分析表明,蒸發(fā)器與冷凝器結(jié)構(gòu)和運(yùn)行條件相同時(shí),單回路純工質(zhì)的泵驅(qū)動(dòng)極限溫度效率為50%�；跍夭罹鶆蛐栽�,提出一種多回路泵驅(qū)動(dòng)兩相回路換熱裝置,推導(dǎo)出換熱裝置的總溫度效率與回路數(shù)和單回路溫度效率的計(jì)算公式。單回路效率高時(shí),回路數(shù)選擇較少為宜,單回路效率低時(shí),回路數(shù)選擇較多為宜。通過(guò)試驗(yàn)研究,分析了泵驅(qū)動(dòng)兩相回路的流量特性和換熱特性。在不同換熱溫差下,隨著流量的增大,換熱量均是先增加后降低再升高。隨著換熱器臺(tái)數(shù)的同步增加,換熱量和溫度效率增加逐漸變緩,換熱器均為1臺(tái)時(shí),換熱量為2.61kW,溫度效率為22.18%,兩器均為3和6臺(tái)時(shí),換熱量分別為4.19 kW和4.43 kW,溫度效率分別為34.89%和37.81%。分析每個(gè)換熱器進(jìn)出口工質(zhì)和水溫度發(fā)現(xiàn),蒸發(fā)器內(nèi)存在溫差和換熱窄點(diǎn),蒸發(fā)器的換熱量主要在首尾兩臺(tái)換熱器,中間換熱器的換熱量占總換熱量較小。在理論和試驗(yàn)基礎(chǔ)上,搭建了數(shù)據(jù)中心用泵驅(qū)動(dòng)兩相回路換熱裝置,試驗(yàn)結(jié)果表明:在10°C溫差下,換熱裝置的換熱量為12.47kW,COP為3.75,25°C溫差時(shí),換熱量為31.17kW,COP為9.37。分析流量和阻力特性得出,蒸發(fā)器出口工質(zhì)干度在0.3至0.6的范圍時(shí)換熱量變化不顯著,較為適宜。隨著室外溫度變化,機(jī)組換熱量與室內(nèi)外溫差成線性關(guān)系。通過(guò)分析其換熱特性、流量特性和室內(nèi)外換熱溫差特性,提出換熱裝置應(yīng)用于數(shù)據(jù)中心自然冷卻的控制策略。
[Abstract]:The energy problem is one of the three basic problems of the development of modern society. With the advent of the era of big data, and the number of data center energy consumption increased rapidly, the air conditioning energy consumption accounted for about 40% of total energy consumption. In the transition season and winter, can use outdoor natural cold source of the data center cooling, reducing the energy consumption. This paper designs a pumped two-phase heat transfer device used for data center cooling, through simulation and experiments on the heat transfer characteristics are studied, the main contents include: the refrigerant in the evaporator outlet and inlet of the condenser based on the state, summed up the four kinds of circulation patterns, superheat cycle, two-phase cycle, cold and cold - two-phase cycle cycle through the theory and experiment found that two-phase cycle is the best model. The one-dimensional steady-state mathematical model is established using pumped two-phase heat transfer and pressure drop equation, and analyzes the period of resistance on the system Effect of circulation and heat transfer. With the increase of refrigerant flow resistance of evaporator inlet to the reservoir inlet, evaporator inlet subcooling degree increased with the increase of export to the condenser; the liquid storage tank inlet resistance, refrigerant evaporator inlet and outlet of the condenser undercooling were increased; with the increase of resistance of evaporator or condenser heat transfer, first increased and then decreased. The evaporator and the condenser connecting pipe and condenser outlet to the reservoir inlet connection pipe resistance increases, two for the total heat transfer rate decreased gradually, the heat transfer rate of attenuation is larger than the latter. The corresponding resistance in the evaporator, refrigerant temperature increased first and then decreased, when the saturated liquid refrigerant when the evaporator temperature and heat pinch pinch. Heat distribution mainly concentrated in the inlet and outlet section of the heat exchanger evaporator. The condenser, refrigerant temperature gradually decreased, the condenser heat transfer in micro element Decreased gradually. When the working fluid saturated liquid, condenser temperature and heat transfer through the inflection point inflection point. Analysis shows that the evaporator and the condenser structure and operation conditions, the single loop of pure refrigerant pump drive limit temperature efficiency of 50%. temperature uniformity is proposed based on the principle of two-phase loop of a multi loop heat pump device efficiency formula and loop temperature heat exchanger is deduced and the number of single loop temperature efficiency. High efficiency single loop, loop number less suitable for single loop low efficiency, large number of loop selection is appropriate. Through experimental research, analysis of the flow characteristics of the pump driven two-phase loop and change thermal characteristics. In different heat transfer temperature difference, along with the increase of flow rate, the heat transfer is increased first and then decreased and then increased. With the increase of heat exchanger units, heat transfer and temperature efficiency increased gradually slow, heat exchangers are 1, heat 2.61kW, temperature efficiency of 22.18% and two are 3 and 6, the heat transfer were 4.19 kW and 4.43 kW, the temperature efficiency were 34.89% and 37.81%. analysis of each heat exchanger inlet and outlet refrigerant and water temperature, evaporator temperature and heat transfer in memory to narrow the heat transfer in the evaporator, the main and two heat exchangers, intermediate heat exchanger heat total heat exchanger is small. Based on the theory and experiment, build a data center with a pump driven two-phase loop heat exchanger, experimental results show that the temperature difference of 10 C, the amount of heat exchanger heat exchanger for 12.47kW, COP for 3.75,25 ~ C temperature, heat transfer for the 31.17kW, COP and 9.37. analysis in order to obtain the flow resistance characteristics, the outlet of the evaporator refrigerant dryness in the range of 0.3 to 0.6 of the heat did not change significantly, more suitable. With the outdoor temperature changes, unit heat transfer and the indoor temperature is linear By analyzing the characteristics of heat transfer, flow rate and temperature difference between indoor and outdoor heat transfer, the control strategy for the application of heat exchanger to the natural cooling of the data center is put forward.

【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TK124;TP308

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 楊茂光;;乙二醇空調(diào)在內(nèi)蒙古移動(dòng)節(jié)能改造中的應(yīng)用[J];電信技術(shù);2008年08期

2 周峰;田昕;馬國(guó)遠(yuǎn);;IDC機(jī)房用熱管換熱器節(jié)能特性試驗(yàn)研究[J];土木建筑與環(huán)境工程;2011年01期

，

本文編號(hào)：1401112