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臺灣能源期刊論文全文

臺灣能源期刊第6卷第2期內容

出刊日期:June, 2019

題目
熱驅動儲冷技術簡介與研析
Title
Heat Driven Cold Storage System
作者
陳志豪、康育豪、陳鈞振、顏詩芸、曾鵬樟、鄭名山
Authors
Chih-Hao Chen, Yu-Hao Kang, Jiun-Jen Chen, Shih-Yun Yen, Pen-Chang Tseng, Ming-Shan Jeng
摘要
夏季尖峰負載過高的問題將成為臺灣走向綠色能源與非核家園的主要障礙,利用儲冰系統移轉夏季尖峰用電應是一種可行的方法,而傳統儲冰系統由於使用固液相變化材料作為儲冷介質,其儲能密度低,因此存在著體積過大、結冰熱阻變大與熱交換器冷縮熱脹毀損等問題;而吸附式或吸收式等熱驅動儲冷系統,則可利用液氣相變化材料作為儲冷介質,大幅提升儲冷密度,且在室溫下可穩定保存,故極有機會能改善傳統儲冰空調的問題。根據大部分文獻之實際測試結果指出,目前吸收式儲冷系統只能有200~400 kJ/kg的儲能密度,其低於理論值原因,在於其使用100oC以下再生之吸收劑,吸收效果較差,加上系統若有加裝太陽能熱水,更會因熱源不穩定性、成本較高與體積過大等問題,而使得吸收式儲冷系統目前仍無法與傳統儲冰系統競爭;而吸附式儲冷系統,因傳統固態吸附劑吸附率低,故其儲能密度又較吸收式更低。基於上述分析,未來若可開發適合之離子液體材料應用於吸收式儲冷系統,因其吸收效果較佳且不會有結晶與金屬腐蝕等問題,將可改善傳統吸收式儲冷系統之缺點,同時利用離子液體可流動性之優勢,將可應用於大型儲能系統中。而吸附式儲冷系統,若能以最新有機金屬骨架材料做為吸附劑,由於其再生溫度低且有較高吸附率,再藉由鹽類等吸收劑改質成孔洞內富含鹽類之複合材料,亦可大幅提升吸附式儲冷之應用性,其理論儲冷密度將可高達到約600 kJ/kg,但因固態吸附劑較無法流動,故適合應用於小型或是分散型儲冷系統中。因此本研究將針對低溫再生(<80oC)之離子液體材料或金屬有機骨架材料進行研析,未來若能使用高效率高穩定性的熱泵系統,做為吸附式或吸收式儲冷系統的供熱源,將可大幅提升熱驅動儲冷系統之市場競爭性。
關鍵字
儲冷系統,熱驅動空調,移轉尖離峰用電
Abatract
High peak load will be one of the main obstacles for Taiwan moving forwards green renewable energy and nuclear-free homeland. The ice storage system is one of the feasible ways for shifting the peak load of air conditioning electricity. The traditional ice storage system used solid-liquid phase change materials as storage medium, but the volume of the system is too large to be applied. Moreover, the thermal resistance of ice and the heat exchanger damaged by thermal expansion contraction are the main issues for the traditional ice systems. Heat driven air-conditioning systems (HDAC), such as absorption or adsorption chiller systems, not only can use the latent heat of liquid-gas phase change as a storage medium significantly increasing the cold storage density, but also can store the cold energy at the ambient temperature. All of these advantages make HDAC have enormous potential to replace traditional ice storage systems. According to references mentioned, the absorption chillier prototype test results show that the energy storage density is about 200~400 kJ/kg. The values are almost the same level to the traditional ice systems. Because of the low sorption capacity of absorbent or desiccant at low regeneration temperature condition (<100oC), the storage energy density is actually lower the highest theoretical one. On the other hand, if the heat source come from solar, the cost, volume of the system and undulate heat supply will decline the competitiveness of HDAC systems. The adsorption chillier has lower storage energy density than the absorption chillier due to solid adsorbent with low adsorption capacity. However, though impregnated with salt absorbent, the composite desiccant have a highest theoretical storage energy density of 600 kJ/kg. In the future, developing a new absorbent regenerated at low temperature, like non-crystallized ionic liquids, can improve the performance and the maintenance costs. The liquidity advantage of absorbent let absorption chillier is suitable to apply in large-scale cold storage systems. Simultaneously, Metal Organic Frameworks (MOFs) which can regenerate in the low temperature and have high adsorption capacity also make the adsorption chillier competitive. Nevertheless, the non-mobility of solid desiccant limit the system applications and suits for the small or distributed cold storage systems. When the new low regeneration temperature absorbents and adsorbents are developed, HDAC driven by the high efficient and stable heat pumps significantly will increase the market competitiveness.
Keywords
cold storage, heat driven chillier, shifting peak load.