氣化過程熔渣形成機(jī)理、流變特性及傳熱過程研究年度科技報告

劉海峰　梁欽鋒　許建良

摘 要：我國能源資源有兩個特點，一是油氣資源匱乏，煤炭相對豐富，二是人均占有量不足。面對日趨復(fù)雜的國際政治、經(jīng)濟(jì)形勢，我國的能源戰(zhàn)略需求必須符合國情，為此國家確定的能源戰(zhàn)略是“節(jié)能優(yōu)先，立足國內(nèi)，煤為基礎(chǔ)，多元發(fā)展”。可以預(yù)見，在未來幾十年內(nèi)，煤炭在能源結(jié)構(gòu)中仍將占主導(dǎo)地位，它是我國戰(zhàn)略上最安全和最可靠的能源資源。通過發(fā)展大規(guī)模煤氣化技術(shù)，清潔高效地利用煤炭資源對保障國家能源戰(zhàn)略安全具有重要意義。大規(guī)模高效清潔煤氣化是支撐相關(guān)產(chǎn)業(yè)發(fā)展的核心技術(shù)。大規(guī)模高效煤氣化技術(shù)是發(fā)展煤基化學(xué)品生產(chǎn)、煤基液體燃料（合成油品、甲醇、二甲醚等）、合成天然氣（SNG）、IGCC發(fā)電、制氫、燃料電池、直接還原煉鐵及多聯(lián)產(chǎn)系統(tǒng)等過程工業(yè)的基礎(chǔ)，是這些行業(yè)的公共技術(shù)、關(guān)鍵技術(shù)和龍頭技術(shù)。氣流床氣化技術(shù)是潔凈煤技術(shù)的主要發(fā)展方向，其中原料適應(yīng)更廣泛、操作更靈活的冷壁式氣化爐開發(fā)迫切需要研究高溫、還原性氣氛下熔渣形成機(jī)理、流變特性及傳熱規(guī)律。氣化反應(yīng)生成的熔渣大部分沉積在氣化爐內(nèi)壁上形成一流動渣層，沿壁面流出氣化室。固態(tài)熔渣和流動態(tài)熔渣從礦物組成、內(nèi)部結(jié)構(gòu)等方面存在極大差別，對燃燒過程固態(tài)熔渣特性已有廣泛研究，而對氣化過程還原性氣氛下熔渣特性研究幾乎處于空白。研究流動態(tài)下熔渣形成機(jī)理、沉積規(guī)律、熔渣分布和傳熱引起的相變過程，對掌握氣流床氣化爐特別是冷壁式氣化爐工程放大依據(jù)、確保氣化爐安全長周期運行有重要意義。該課題總體目標(biāo)是研究高溫、高壓和還原性氣氛下熔渣的形成機(jī)理、流動特性與傳熱過程規(guī)律，為冷壁式氣化爐的設(shè)計和優(yōu)化提供理論依據(jù)，擬研究的關(guān)鍵問題包括：研究水冷壁表面熔渣流動行為和相變規(guī)律，建立傳熱模型；高溫還原氣氛下灰渣的化學(xué)組成和礦物組成的變化規(guī)律；探索灰渣礦物質(zhì)組成與其流變特性和熔融特性之間的對應(yīng)關(guān)系等；研究多原料共氣化灰渣的化學(xué)組成和礦物組成，探索含釩、鎳等金屬氧化物灰渣的熔融特性和粘度變化規(guī)律，以確定合理的共氣化混合比例和反應(yīng)溫度；研究不同煤種混合氣化時，煤灰組成對熔渣特性的影響機(jī)理，建立混煤灰熔點預(yù)測模型，確定合理的煤混配比例。通過本課題掌握氣流床氣化爐水冷壁襯里表面的熔渣沉積、流動、相變和傳熱規(guī)律以及掌握熔渣粘溫特性和熔融特性等理化性質(zhì)等，為已開車運行氣流床氣化裝置的長周期穩(wěn)定高效運行條件優(yōu)化提供理論指導(dǎo)，也為開發(fā)和優(yōu)化自主知識產(chǎn)權(quán)的氣流床氣化技術(shù)提供了堅實的理論基礎(chǔ)。

關(guān)鍵詞：氣流床氣化 熔渣 水冷壁

Abstract：There are two characteristics for China's energy resources. Firstly the oil and gas resource are scarce but the coal is rich， secondly the per capita resource is insufficient. So coal which is the safest and most reliable energy resources in China will still occupy the dominant position in the energy structure in the next few years. It is great significance that the development of large-scale coal gasification technology is to achieve the clean and efficient use of coal and national energy security. The large-scale and high efficiency clean coal gasification is the key technology to support the development of related industries including chemical products， liquid fuel （synthetic oil， methanol， dimethyl ether et al）， the synthetic natural gas （SNG）， IGCC power generation， hydrogen， fuel cells， direct reduction iron making and polygeneration system et al. The entrained flow gasification technology is the main direction of clean coal technology. The study on slag formation mechanism， slag rheological properties and membranes wall heat transfer law under the high temperature， high pressure and reducing atmosphere is a basis for developing the membranes wall lining coal gasification technology. Above research would provide the theory evidences on design and operating of gasifier. It is the main purpose of this subject that understanding the law of slag formation mechanism and membranes wall heat transfer process at high temperature， high pressure and reducing atmosphere. There are several facts in this field， the slag flow behavior and phase transformation is firstly studied， secondly the heat transfer model is established， the third is the transformation of slag chemical composition and mineral under high-temperature reducing atmosphere. Above study， such as the law of the slag deposition and flow， phase transformation， slag viscosity temperature characteristics and heat transfer， is to provide theoretical guidance for the long period stable operation of gaifier and development of independent intellectual property rights membranes wall lining gasifier.

Key Words：Entrained flow gasification；Slag；Membrane wall

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