太陽(yáng)能空調(diào)蓄熱水箱特性研究

2012-05-22 王愛(ài)輝 南京工業(yè)大學(xué)

  根據(jù)南京地區(qū)的太陽(yáng)輻射強(qiáng)度及典型建筑負(fù)荷的日變化規(guī)律,得出單位集熱面積時(shí)可滿足的負(fù)荷建筑面積及蓄熱水箱溫度變化規(guī)律;并對(duì)幾種不同體積蓄熱水箱進(jìn)行了分季節(jié)的啟動(dòng)時(shí)間分析。結(jié)果表明,蓄熱水箱體積影響著戶式太陽(yáng)能空調(diào)系統(tǒng)性能:夏季,在單位集熱面積的情況下,水箱體積以70L為基準(zhǔn),體積增大114%,熱水工作范圍減小54%,可承擔(dān)負(fù)荷減小25.2%,同時(shí),體積增大到150L后啟動(dòng)時(shí)間也變?yōu)樵瓉?lái)的2倍以上,可見(jiàn),蓄熱水箱體積越小越好,但它存在一個(gè)最小值隨著日工作時(shí)間的延長(zhǎng)而增大;冬季蓄熱水箱體積對(duì)負(fù)荷的影響較小,但即使70L的水箱,冬季啟動(dòng)耗時(shí)也比夏季多4h。

  關(guān)鍵詞:太陽(yáng)能空調(diào);蓄熱水箱;負(fù)荷建筑面積;水箱體積

  Abstract: The changing regularity of temperature in hot water tank and load of building reached under the unit area of collector was obtained according to the undulations of solar radiation intensity and load of typical buildings in Nanjing area,and the time for tank with different volumes to start-up was analyzed in summer and winter.The results show that the performance of the household air conditioning system is impacted by the volume of the tank : in summer,under the unit area of collector and the tank of 70L,with the volume increased by 114%,the range of the tempertature of hot water decreased by 54% and the building area of the load decreased by 25.2%,at the same time,with the volume increased to 150L,the time for start-up is twice longer than before,that said,it was better,the tank smaller,but the minimum volume is existed,which with the extending of working time bigger and bigger;in winter,the effect of the tank volume on the load is small,but the time for start-up is 4 hours longer in summer than in winter,with the tank of 70L.

  Keywords: solar air conditioning;hot water tank for heat storage;the building area of load;the volume of the tank

  隨著人們對(duì)環(huán)境問(wèn)題的重視及能源的緊張,對(duì)清潔無(wú)污染的太陽(yáng)能的開(kāi)發(fā)和利用顯得相當(dāng)重要。太陽(yáng)能空調(diào)系統(tǒng)作為其中不可或缺的一部分,近年來(lái)得到廣泛的關(guān)注[1]。但是對(duì)于太陽(yáng)能空調(diào)系統(tǒng)中的蓄熱問(wèn)題,一直是困擾太陽(yáng)能空調(diào)發(fā)展的重要問(wèn)題,之前很多學(xué)者對(duì)蓄熱水箱以溫度分層水箱為模型做了研究[2,3],為蓄熱水箱容積的確定奠定了理論基礎(chǔ),但現(xiàn)階段較為穩(wěn)定可靠的還是整體式的水箱。本文對(duì)整體式水箱從體積大小和南京地區(qū)房間負(fù)荷的季節(jié)變化出發(fā),研究單位集熱面積下,無(wú)輔助熱源時(shí),系統(tǒng)不同季節(jié)的可承擔(dān)負(fù)荷及啟動(dòng)特性,為戶式太陽(yáng)能空調(diào)系統(tǒng)的節(jié)能研究提供依據(jù)。

  (1) 對(duì)于太陽(yáng)能空調(diào)系統(tǒng),夏季單位集熱面積下,蓄熱水箱以70L 為基準(zhǔn),體積增大114%時(shí),熱水工作范圍減小54%,可承擔(dān)負(fù)荷減小25.2%,即體積是越小越好的,但又不能太小使得熱水工作溫度超過(guò)臨界值,可是隨著日工作時(shí)間的延長(zhǎng),最小體積需要增大; 冬季時(shí),水溫和負(fù)荷對(duì)體積的要求較低;

  (2) 系統(tǒng)的啟動(dòng)與蓄熱水箱的體積密切相關(guān),無(wú)論冬季還是夏季,蓄熱水箱體積增大114%達(dá)到150L,啟動(dòng)時(shí)間都延長(zhǎng)為2 倍以上; 分季節(jié)來(lái)看,蓄熱水箱為70L 時(shí),夏季啟動(dòng)也比冬季要少用時(shí)25%,而體積越大,這個(gè)值也越大;

  (3) 如何使夏季蓄熱水箱工作體積的最小值更小而容熱能力更強(qiáng),與此同時(shí),降低水箱內(nèi)水溫的逐時(shí)變化率,提高單位集熱面積可承擔(dān)的負(fù)荷及系統(tǒng)的穩(wěn)定性,并使啟動(dòng)加速,是一個(gè)值得探討的問(wèn)題。

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