發(fā)布時(shí)間：2018-11-09 17:39

【摘要】：相變材料的相變潛熱蓄熱或蓄冷,具有蓄能密度大、溫度變化小的特點(diǎn),在太陽能利用、工業(yè)余熱、建筑節(jié)能和廢熱回收等領(lǐng)域有著廣泛的應(yīng)用。作為固--液相變材料,石蠟具有化學(xué)穩(wěn)定性好、相變潛熱大、來源廣泛、無過冷和相分離現(xiàn)象、價(jià)格低廉等優(yōu)點(diǎn),在相變材料方面得到廣闊應(yīng)用。但其需封裝、熱導(dǎo)率小的缺點(diǎn),制約了其在儲熱領(lǐng)域中的應(yīng)用。本文以石蠟為相變材料,高密度聚乙烯(HDPE)為支撐材料,采用熔融共混法制備石蠟/HDPE定形相變材料(Phase change m a t e r i a l,P C M),對其微觀形貌、滲漏率及熱性能等進(jìn)行測試表征。并探究添加劑及制備工藝對石蠟/HDPE定形PCM滲漏率的影響。研究結(jié)果表明,石蠟和HDPE相容性良好。石蠟/HDPE定形PCM相變焓與石蠟含量有關(guān)。當(dāng)在石蠟/HDPE定形PCM中添加質(zhì)量分?jǐn)?shù)為0.1%的過氧化二異丙苯(D C P)和0.1%的抗氧劑1 0 1 0,在1 5 0℃下熔融共混時(shí),可以獲得低滲漏率定形相變材料。以石蠟為相變材料,HDPE為支撐材料,膨脹石墨(EG)為導(dǎo)熱填料,采用熔融共混法制備石蠟/HDPE/EG導(dǎo)熱定形PCM,對其微觀形貌、熱導(dǎo)率、滲漏率及熱性能等進(jìn)行測試表征,并探究石蠟/H D P E/E G導(dǎo)熱定形P C M熱導(dǎo)率的影響因素。研究結(jié)果表明,石蠟、H D P E和E G三者之間相容性良好。添加E G后,定形P C M滲漏率有所提高,但隨EG含量的增加而降低,EG質(zhì)量分?jǐn)?shù)為15%時(shí),滲漏率低于0.6%。熱導(dǎo)率隨EG含量的增加而增加,EG質(zhì)量分?jǐn)?shù)為15%時(shí),熱導(dǎo)率為1.265 W/(m·K),提高率達(dá)144%。導(dǎo)熱定形PCM的相變焓隨EG含量的增加變化不大。采用二甲苯溶解法探究H D P E及E G對石蠟的包覆作用及E G的分布情況,提出石蠟/HDPE/EG導(dǎo)熱定形PCM的導(dǎo)熱機(jī)理。研究結(jié)果表明,HDPE形成的空間網(wǎng)狀結(jié)構(gòu)以及EG的多孔結(jié)構(gòu)均對石蠟起到良好的包覆作用。HDPE的空間網(wǎng)狀結(jié)構(gòu)對EG也起到包覆作用。蠕蟲狀EG吸附大量石蠟,分布于HDPE形成的空間網(wǎng)狀結(jié)構(gòu)中。石蠟/HDPE定形PCM中加入EG后,導(dǎo)熱載體由聲子變?yōu)樽杂呻娮?大大提高了傳熱速率。
[Abstract]:Phase change latent heat storage or cold storage of phase change materials has been widely used in the fields of solar energy utilization industrial waste heat building energy saving and waste heat recovery because of its high energy storage density and small temperature change. As a solid-liquid phase change material, paraffin has many advantages, such as good chemical stability, large latent heat of phase transition, wide source, no undercooling and phase separation, low price and so on, so it has been widely used in phase change materials. However, its application in the field of heat storage is restricted by its disadvantages of packaging and low thermal conductivity. In this paper, paraffin wax as phase change material, high density polyethylene (HDPE) as supporting material, paraffin wax / HDPE fixed phase change material (Phase change m a t e r i a ln P C M), were prepared by melt blending method. The leakage rate and thermal property were measured and characterized. The effects of additives and preparation process on the leakage rate of paraffin / HDPE PCM were investigated. The results show that the compatibility of paraffin and HDPE is good. The enthalpy of phase transition of paraffin / HDPE PCM is related to the content of paraffin. When 0.1% diisopropyl peroxide (D C P) and 0.1% antioxidant (1010%) were added into paraffin / HDPE PCM, the low leakage setting phase change material could be obtained by melt blending at 150 鈩，

本文編號：2321109