【摘要】：由于地鐵沿線都是城市繁華區(qū)域和主干道,很難在地鐵站外地面上找到既與周邊環(huán)境協(xié)調(diào),又滿足地鐵站空調(diào)系統(tǒng)冷卻塔安裝環(huán)境的安裝位置,因此,研究一種換熱效率高、適于地鐵等地下建筑的專用冷卻器來替代目前常用的冷卻塔,具有重要的工程應(yīng)用價值。本文在兩側(cè)旋轉(zhuǎn)布水間接蒸發(fā)冷卻器理論研究的基礎(chǔ)上,開發(fā)了機械傳動裝置以實現(xiàn)換熱器兩側(cè)旋轉(zhuǎn)布水,并搭建了兩側(cè)旋轉(zhuǎn)布水間接蒸發(fā)冷卻器性能測試實驗臺,研究了各參數(shù)對其性能的影響,為地鐵專用冷卻器的開發(fā)提供依據(jù)。通過實驗研究噴嘴與換熱器間距、雙組換熱盤管間距、單雙側(cè)旋轉(zhuǎn)布水對換熱器性能的影響,以及設(shè)計正交實驗,研究換熱器分別為單組、雙組時,在三種布置方式下,噴水量、轉(zhuǎn)速、空氣溫度、管內(nèi)冷卻水流量、冷卻水進口溫度等因素對換熱器傳熱傳質(zhì)性能的影響,實驗結(jié)果表明：(1)換熱器兩側(cè)旋轉(zhuǎn)布水時與單側(cè)相比,換熱器垂直氣流布置時換熱量提高了30.8%,平行氣流布置時提高了20%。同時,在上述兩種布置方式下,噴嘴到換熱器間距、雙組換熱盤管間距對其性能影響較小。(2)單組換熱器垂直氣流布置時,空氣速度由2.5m/s增至3m/s時,換熱量先增加至0.602kw/m2(即空氣速度為2.75m/s)后保持不變,冷卻水流量由400L/h增至600L/h時,換熱量先減少至0.595kw/m2(即冷卻水流量為500L/h)后不變；雙組換熱器垂直氣流布置時,隨著布水裝置轉(zhuǎn)速、冷卻水流量的增大,換熱量呈現(xiàn)先減少后增加的趨勢,同時還表明,雙組布置時的換熱量與單組布置時相比增加了1.96%。(3)單組、雙組換熱器平行氣流布置時,雙組換熱器時的冷卻水流量的增大使換熱量呈現(xiàn)先減少后增加的趨勢,且雙組換熱器的換熱性能比單組布置時提高了17.4%。(4)單組換熱器中心開孔正對氣流布置時,轉(zhuǎn)速由50r/min增至100r/min時,換熱量呈現(xiàn)先減少后增加趨勢;雙組布置時,轉(zhuǎn)速的增加使換熱量先增加至0.991 kw/m2后減少,即存在最佳轉(zhuǎn)速76r/min。單組換熱器布置時的換熱量比雙組時提高了16.67%。(5)在不同布置方式下各因素對換熱器性能影響的主次順序各不相同,同時,三種布置方式中,換熱器中心開孔正對氣流布置時換熱器換熱性能最佳。
[Abstract]:As there are busy urban areas and main roads along the subway line, it is difficult to find a location on the ground outside the subway station that not only coordinates with the surrounding environment, but also meets the installation environment of the cooling tower of the subway air conditioning system. Therefore, the study of a kind of heat transfer efficiency is high. Special coolers suitable for underground buildings such as subway have important engineering application value to replace the commonly used cooling towers. Based on the theoretical research of indirect evaporative cooler with two sides of rotating water distribution, a mechanical transmission device is developed to realize the rotating distribution of water on both sides of the heat exchanger, and a test bench for testing the performance of the indirect evaporative cooler with two sides of rotating water distribution is built. The influence of various parameters on its performance is studied, which provides the basis for the development of special cooler for subway. The effects of the distance between nozzle and heat exchanger, the distance between two groups of heat transfer coils and the rotating water distribution on the performance of the heat exchanger were studied by experiments. The orthogonal design experiment was carried out to study the effect of the heat exchanger on the performance of the heat exchanger under three different arrangement modes, when the heat exchanger was divided into single group and double group. The effects of water injection rate, rotational speed, air temperature, cooling water flow rate and inlet temperature of cooling water on the heat and mass transfer performance of the heat exchanger are discussed. The experimental results show that: (1) when the water distribution is rotated on both sides of the heat exchanger, it is compared with the one side. The heat transfer increased by 30.8 when the vertical flow was arranged, and by 20 when the parallel flow was arranged. At the same time, the distance between nozzle and heat exchanger and the distance between two groups of heat exchanger coils have little effect on the performance of the two kinds of arrangement. (2) when the vertical flow of single heat exchanger is arranged, the air velocity increases from 2.5m/s to 3m/s. When the cooling water flow rate increased from 400L/h to 600L/h, the heat transfer decreased to 0.595kw/m2 (that is, the cooling water flow rate was 500L/h) and then remained unchanged after the increase of heat transfer to 0.602kw/m2 (that is, air velocity is 2.75m/s). When two heat exchangers are arranged in vertical air flow, with the increase of cooling water flow rate and the speed of water distribution unit, the heat transfer appears to decrease first and then increase. At the same time, it is also shown that, Compared with the single group arrangement, the heat transfer increased by 1.96. (3) the cooling water flow increased with the increase of the cooling water flow in the two groups of heat exchangers, and the heat exchange decreased first and then increased. The heat transfer performance of the two-group heat exchanger is 17.4% higher than that of the single group heat exchanger. (4) when the center opening of the single group heat exchanger is arranged to the airflow, when the rotational speed increases from 50r/min to 100r/min, the heat transfer rate decreases first and then increases; With the increase of rotational speed, the heat transfer increased to 0.991 kw/m2 and then decreased, that is, the optimum rotation speed was 76 r / min. The heat transfer of single heat exchanger is 16.67767 higher than that of double heat exchanger. (5) the primary and secondary order of the influence of each factor on heat exchanger performance is different under different arrangement modes, meanwhile, among the three arrangement modes, The heat exchanger has the best heat transfer performance when the center of the heat exchanger is open to the airflow.
【學(xué)位授予單位】：長沙理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU962

【參考文獻】

相關(guān)碩士學(xué)位論文 前1條

1 沈家龍;蒸發(fā)式冷凝器傳熱傳質(zhì)理論分析及實驗研究[D];華南理工大學(xué);2005年

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本文編號：2347778