相變材料

圖為乙酸鈉加熱墊（英語：heating pad），當乙酸鈉溶液晶化時，放出大量熱。

加熱墊晶化放熱視頻

相變材料（英語：phase change material，縮寫為：PCM）是指在相變時放出或吸收大量熱，以達到加熱或降溫作用的物質。通常情況下，該物質將在液態和固態間進行轉變，但也可以在非傳統狀態間進行轉變，例如從一種結晶態轉變為能量更高或更低的另一種結晶態。

相變材料物質狀態改變時所需的熔化熱通常遠大於其顯熱（英語：sensible heat），相變溫度（PCT）附近融化和凝固時，相變材料可以儲存和釋放巨大的能量。例如，冰融化成水的熔化熱為333.55 J/g，即一克冰需要吸收333.55 J熱量才能融化成水。然而一克水吸收4.18 J熱量溫度升高1度。因此水/冰是一種非常有用的相變材料，自阿契美尼德王朝開始人們就用它在冬天釋放熱量，在夏天給房子降溫。

相變材料可按組成物質種類進行分類。有機相變材料通常從石油、植物或動物上提取，水合鹽相變材料通常由海水或礦物中提取。還有一類是固體轉變為固體的相變材料。他們在生活中有着廣泛的應用，加熱墊、電話配電箱冷卻和服飾製造等都可以看到相變材料的身影。

特性和分類

液體→固體、固體→液體、固體→氣體和液體→氣體的變化過程均可儲存潛熱，但只有液體→固體和固體→液體變化過程較為現實。儘管液體→氣體過程中轉換的熱量更多，但是氣態體積較大，存儲需要高壓，不易於使用。固態→固態的轉變速度十分緩慢，轉換的熱量相對較少。

固態-液態相變材料在達到相變溫度前，其特性與顯熱（英語：sensible heat）儲存材料相似，吸收熱量的同時溫度逐漸上升。但是當到達相變溫度（熔點）時，開始大量吸收熱量，但是溫度保持不變，材料完全融化後，溫度繼續上升。當液態材料所處環境溫度下降時便開始凝固，釋放其所儲存的潛熱。各種相變材料可供選擇，−5到190 °C之間任意相變溫度均有對應。^[1]而在20-30 °C人體舒適溫度範圍內，有些材料潛熱吸收十分高效，可以達到200 kJ/kg，與之對應的石料的熱容一般為1 kJ/kg.°C，因此保持相同溫度時每千克材料吸收的熱量是石料的200倍。^[2]水的比熱容為4.21 kJ/kg.°C，該材料存儲密度為水的12.5倍至50倍之間。

有機相變材料

碳氫化合物，主要是石蠟(C_nH_2n+2)和脂質類物質，也有一種是糖醇。^[3]^[4]^[5]

優點
- 凝固時沒有過冷效應
- 能夠一致地融化
- 自成核性質
- 與常規結構材料相容性好
- 沒有隔離
- 化學性質穩定
- 安全、無反應
缺點
- 固態導熱係數低，冷凍過程中需要保持高傳熱率。已發現的發現納米複合材料可有效將熱導率提高216％^[6]^[7]
- 體積潛熱儲存容量可能較低
- 易燃，置於專門的容器中可以有效隔離。

非有機相變材料

水合鹽 (M_xN_yH₂O) ^[8]

優點
- 體積潛熱儲存容量高
- 易於獲取，成本低
- 高熔點
- 熱傳導率高
- 熔化熱高
- 不可燃
缺點
- 融化不一致，容易出現相位分離^[9]
- 對大多數材料有腐蝕性^[10]^[11]^[12]可以封裝在不與之反應的塑料內克服
- 某些混合物體積變化很大
- 固態到液態轉變過程中出現的過冷現象是個麻煩，需要使用成核劑，反覆使用後可能不再起作用

應用

治療新生兒窒息（英語：birth asphyxia）時在手術台上鋪設相變材料^[14]^[15]

應用領域^[1]^[17]包括並不局限於：

儲熱（英語：Thermal energy storage）
太陽能鍋
冷能電池（英語：Cold Energy Battery）
建築溫控
發動機和電機降溫
製冷：食物、飲料、咖啡、葡萄酒、奶製品、溫室
延緩表面凝霜^[16]
醫療器械：血液運輸、操作台、熱治療、新生兒窒息治療^[14]
笨重的衣服或服裝下的人體冷卻.
廢熱回收
錯峰（英語：Off-peak）電力利用：加熱、冷卻水
熱泵系統
被動存儲綠色建築(HDPE（英語：High-density polyethylene）、石蠟)
緩和化學反應放熱過程中的溫度峰值
太陽能發電站
航天器溫控系統
車輛熱舒適性
電子儀器溫度保險絲
服裝用紡織品
電腦硬件冷卻
帶有熱能儲存功能的的渦輪機入風口冷卻
熱帶地區的電信設備保護

參見

熱導管

Raoux, S. Phase Change Materials. Annual Review of Materials Research. 2009, 39: 25–48. Bibcode:2009AnRMS..39...25R. doi:10.1146/annurev-matsci-082908-145405.
Phase Change Matters （頁面存檔備份，存於網際網路檔案館） (industry blog)

參考資料

^ ^1.0 ^1.1 Kenisarin, M; Mahkamov, K. Solar energy storage using phase change materials. Renewable and Sustainable –1965. 2007, 11 (9): 1913–1965. doi:10.1016/j.rser.2006.05.005.
^ Sharma, Atul; Tyagi, V.V.; Chen, C.R.; Buddhi, D. Review on thermal energy storage with phase change materials and applications. Renewable and Sustainable Energy Reviews. 2009, 13 (2): 318–345. doi:10.1016/j.rser.2007.10.005.
^ "Heat storage systems" （頁面存檔備份，存於網際網路檔案館） (PDF) by Mary Anne White, brings a list of advantages and disadvantages of Paraffin heat storage. A more complete list can be found in AccessScience （頁面存檔備份，存於網際網路檔案館） website from McGraw-Hill, DOI 10.1036/1097-8542.YB020415, last modified: March 25, 2002 based on 'Latent heat storage in concrete II, Solar Energy Materials, Hawes DW, Banu D, Feldman D, 1990, 21, pp.61–80.
^ Floros, Michael C.; Kaller, Kayden L. C.; Poopalam, Kosheela D.; Narine, Suresh S. Lipid derived diamide phase change materials for high temperature thermal energy storage. Solar Energy. 2016-12-01, 139: 23–28. Bibcode:2016SoEn..139...23F. doi:10.1016/j.solener.2016.09.032.
^ Agyenim, Francis; Eames, Philip; Smyth, Mervyn. Experimental study on the melting and solidification behaviour of a medium temperature phase change storage material (Erythritol) system augmented with fins to power a LiBr/H2O absorption cooling system. Renewable Energy. 2011-01-01, 36 (1): 108–117. doi:10.1016/j.renene.2010.06.005.
^ Fleishcher, A.S. Improved heat recovery from paraffn-based phase change materials due to the presence of percolating graphene networks. Improved Heat Recovery from Paraffn-based Phase Change Materials Due to the Presence of Percolating Graphene Networks. 2014, 79: 324–333.
^ (2015). Thermal energy storage using phase change materials: fundamentals and applications. Springer
^ Phase Change Energy Solutions https://id.elsevier.com/as/authorization.oauth2?platSite=SD%2Fscience&scope=openid+email+profile+els_auth_info+urn%3Acom%3Aelsevier%3Aidp%3Apolicy%3Aproduct%3Ainst_assoc&response_type=code&redirect_uri=https%3A%2F%2Fwww.sciencedirect.com%2Fuser%2Fidentity%2Flanding&authType=SINGLE_SIGN_IN&prompt=none&client_id=SDFE-v3&state=retryCounter%3D0%26csrfToken%3D7b73d88c-a46a-4ce5-8a58-7a21b367a560%26idpPolicy%3Durn%253Acom%253Aelsevier%253Aidp%253Apolicy%253Aproduct%253Ainst_assoc%26returnUrl%3Dhttps%253A%252F%252Fwww.sciencedirect.com%252Ftopics%252Fengineering%252Fsalt-hydrate%26prompt%3Dnone%26cid%3Dtpp-9ec8e252-5eaf-44ce-a8d4-838d9800b9b3. [February 28, 2018]. 缺少或|title=為空 (幫助)
^ Cantor, S. DSC study of melting and solidification of salt hydrates. Thermochimica Acta. 1978, 26 (1–3): 39–47 [2020-06-27]. doi:10.1016/0040-6031(78)80055-0. （原始內容存檔於2021-03-11）.
^ olé, A.; Miró, L.; Barreneche, C.; Martorell, I.; Cabeza, L.F. Corrosion of metals and salt hydrates used for thermochemical energy storage. Renewable Energy. 2015, 75: 519–523. doi:10.1016/j.renene.2014.09.059. ^{[失效連結]}
^ A. Sharma; V. Tyagi; C. Chen; D. Buddhi. Review on thermal energy storage with phase change materials and applications. Renewable and Sustainable Energy Reviews. February 2009, 13 (2): 318–345. doi:10.1016/j.rser.2007.10.005.
^ Sharma, Someshower Dutt; Kitano, Hiroaki; Sagara, Kazunobu. Phase Change Materials for Low Temperature Solar Thermal Applications (PDF). Res. Rep. Fac. Eng. Mie Univ. 2004, 29: 31–64 [2020-06-27]. （原始內容存檔 (PDF)於2020-06-27）.
^ Infinite R™. Insolcorp, Inc. [2017-03-01]. （原始內容存檔於2020-12-02）.
^ ^14.0 ^14.1 Aravind, Indulekha; Kumar, KP Narayana. How two low-cost, made-in-India innovations MiraCradle & Embrace Nest are helping save the lives of newborns. timesofindia-economictimes. 2015-08-02 [2020-06-27]. （原始內容存檔於2020-08-20）.
^ MiraCradle - Neonate Cooler. [2022-01-19]. （原始內容存檔於2021-03-11）.
^ ^16.0 ^16.1 Chatterjee, Rukmava; Beysens, Daniel; Anand, Sushant. Delaying Ice and Frost Formation Using Phase-Switching Liquids. Advanced Materials. 2019, 0 (17): 1807812. ISSN 1521-4095. PMID 30873685. doi:10.1002/adma.201807812  （英語）.
^ Omer, A. Renewable building energy systems and passive human comfort solutions. Renewable and Sustainable Energy Reviews. 2008, 12 (6): 1562–1587. doi:10.1016/j.rser.2006.07.010.

來源

PHASE CHANGE MATERIAL (PCM) BASED ENERGY STORAGE MATERIALS AND GLOBAL APPLICATION EXAMPLES

Zafer URE M.Sc., C.Eng. MASHRAE HVAC Applications （頁面存檔備份，存於網際網路檔案館）

Phase Change Material Based Passive Cooling Systems Design Principal and Global Application Examples

Zafer URE M.Sc., C.Eng. MASHRAE Passive Cooling Application （頁面存檔備份，存於網際網路檔案館）

[Kenisarin-1] 1.0 ^1.1 Kenisarin, M; Mahkamov, K. Solar energy storage using phase change materials. Renewable and Sustainable –1965. 2007, 11 (9): 1913–1965. doi:10.1016/j.rser.2006.05.005.

[2] Sharma, Atul; Tyagi, V.V.; Chen, C.R.; Buddhi, D. Review on thermal energy storage with phase change materials and applications. Renewable and Sustainable Energy Reviews. 2009, 13 (2): 318–345. doi:10.1016/j.rser.2007.10.005.

[3] "Heat storage systems" （頁面存檔備份，存於網際網路檔案館） (PDF) by Mary Anne White, brings a list of advantages and disadvantages of Paraffin heat storage. A more complete list can be found in AccessScience （頁面存檔備份，存於網際網路檔案館） website from McGraw-Hill, DOI 10.1036/1097-8542.YB020415, last modified: March 25, 2002 based on 'Latent heat storage in concrete II, Solar Energy Materials, Hawes DW, Banu D, Feldman D, 1990, 21, pp.61–80.

[4] Floros, Michael C.; Kaller, Kayden L. C.; Poopalam, Kosheela D.; Narine, Suresh S. Lipid derived diamide phase change materials for high temperature thermal energy storage. Solar Energy. 2016-12-01, 139: 23–28. Bibcode:2016SoEn..139...23F. doi:10.1016/j.solener.2016.09.032.

[5] Agyenim, Francis; Eames, Philip; Smyth, Mervyn. Experimental study on the melting and solidification behaviour of a medium temperature phase change storage material (Erythritol) system augmented with fins to power a LiBr/H2O absorption cooling system. Renewable Energy. 2011-01-01, 36 (1): 108–117. doi:10.1016/j.renene.2010.06.005.

[6] Fleishcher, A.S. Improved heat recovery from paraffn-based phase change materials due to the presence of percolating graphene networks. Improved Heat Recovery from Paraffn-based Phase Change Materials Due to the Presence of Percolating Graphene Networks. 2014, 79: 324–333.

[7] (2015). Thermal energy storage using phase change materials: fundamentals and applications. Springer

[8] Phase Change Energy Solutions https://id.elsevier.com/as/authorization.oauth2?platSite=SD%2Fscience&scope=openid+email+profile+els_auth_info+urn%3Acom%3Aelsevier%3Aidp%3Apolicy%3Aproduct%3Ainst_assoc&response_type=code&redirect_uri=https%3A%2F%2Fwww.sciencedirect.com%2Fuser%2Fidentity%2Flanding&authType=SINGLE_SIGN_IN&prompt=none&client_id=SDFE-v3&state=retryCounter%3D0%26csrfToken%3D7b73d88c-a46a-4ce5-8a58-7a21b367a560%26idpPolicy%3Durn%253Acom%253Aelsevier%253Aidp%253Apolicy%253Aproduct%253Ainst_assoc%26returnUrl%3Dhttps%253A%252F%252Fwww.sciencedirect.com%252Ftopics%252Fengineering%252Fsalt-hydrate%26prompt%3Dnone%26cid%3Dtpp-9ec8e252-5eaf-44ce-a8d4-838d9800b9b3. [February 28, 2018]. 缺少或|title=為空 (幫助)

[9] Cantor, S. DSC study of melting and solidification of salt hydrates. Thermochimica Acta. 1978, 26 (1–3): 39–47 [2020-06-27]. doi:10.1016/0040-6031(78)80055-0. （原始內容存檔於2021-03-11）.

[10] é, A.; Miró, L.; Barreneche, C.; Martorell, I.; Cabeza, L.F. Corrosion of metals and salt hydrates used for thermochemical energy storage. Renewable Energy. 2015, 75: 519–523. doi:10.1016/j.renene.2014.09.059. ^{[失效連結]}

[11] A. Sharma; V. Tyagi; C. Chen; D. Buddhi. Review on thermal energy storage with phase change materials and applications. Renewable and Sustainable Energy Reviews. February 2009, 13 (2): 318–345. doi:10.1016/j.rser.2007.10.005.

[12] Sharma, Someshower Dutt; Kitano, Hiroaki; Sagara, Kazunobu. Phase Change Materials for Low Temperature Solar Thermal Applications (PDF). Res. Rep. Fac. Eng. Mie Univ. 2004, 29: 31–64 [2020-06-27]. （原始內容存檔 (PDF)於2020-06-27）.

[13] Infinite R™. Insolcorp, Inc. [2017-03-01]. （原始內容存檔於2020-12-02）.

[economictimes.indiatimes.com-14] 14.0 ^14.1 Aravind, Indulekha; Kumar, KP Narayana. How two low-cost, made-in-India innovations MiraCradle & Embrace Nest are helping save the lives of newborns. timesofindia-economictimes. 2015-08-02 [2020-06-27]. （原始內容存檔於2020-08-20）.

[15] MiraCradle - Neonate Cooler. [2022-01-19]. （原始內容存檔於2021-03-11）.

[#1-16] 16.0 ^16.1 Chatterjee, Rukmava; Beysens, Daniel; Anand, Sushant. Delaying Ice and Frost Formation Using Phase-Switching Liquids. Advanced Materials. 2019, 0 (17): 1807812. ISSN 1521-4095. PMID 30873685. doi:10.1002/adma.201807812  （英語）.

[17] Omer, A. Renewable building energy systems and passive human comfort solutions. Renewable and Sustainable Energy Reviews. 2008, 12 (6): 1562–1587. doi:10.1016/j.rser.2006.07.010.

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