本文選題：液化天然氣 + 冷能�。� 參考：《華南理工大學(xué)》2013年碩士論文

【摘要】：液化天然氣（LNG）是天然氣經(jīng)過脫硫處理，通過低溫工藝?yán)鋬鲆夯傻牡蜏匾后w混合物。LNG作為燃料供給下游用戶使用時會釋放出大量的冷能，約830kJ/kg，傳統(tǒng)工藝中，該部分冷能被海水或空氣帶走，即造成了能源的浪費，也污染了環(huán)境，故此充分回收利用該部分冷能將具有十分重要的理論和現(xiàn)實意義。 目前LNG冷能回收利用面臨著資源供應(yīng)緊張、現(xiàn)貨價格和長期合同價格波動劇烈、LNG冷能利用項目建設(shè)緩慢、冷能利用方式單一、利用效率低下和冷能用戶與冷能供應(yīng)不同步等問題，使得LNG冷能產(chǎn)業(yè)大規(guī)模發(fā)展受阻。本文結(jié)合LNG冷能用于發(fā)電及冰蓄冷空調(diào)供生活區(qū)供冷工藝的優(yōu)勢，根據(jù)LNG冷能利用的火用分析和工質(zhì)與LNG變溫曲線趨勢變化分析，提出了回收LNG高品位冷能用于發(fā)電、低品位冷能用于冰蓄冷空調(diào)的分段回收利用工藝。采用流程模擬技術(shù)、火用分析法，對比工質(zhì)在不同流量下的關(guān)鍵設(shè)備火用效率變化特點，選取最優(yōu)的系統(tǒng)參數(shù)，，即質(zhì)量濃度為32%的乙二醇水溶液為冰蓄冷空調(diào)使用的工質(zhì)；若以丙烷與丁烷的混合物作為發(fā)電工藝的有機混合工質(zhì)，最佳混合比為50%-50%丙烷-丁烷（質(zhì)量分?jǐn)?shù)），當(dāng)LNG流量為1000kg/hr，設(shè)備平均火用效率最大時的混合工質(zhì)最佳流量為1270kg/hr，蒸發(fā)溫度為10℃，蒸發(fā)壓力為0.35MPa，冷凝溫度為-22℃，冷凝壓力為0.11MPa。 將研究結(jié)論應(yīng)用于某電廠，采用該工藝流程經(jīng)行工況模擬和分析，運用價值計算和節(jié)電效益分析法計算了工況下的LNG冷能回收的經(jīng)濟效益。對于一個LNG氣化規(guī)模為35000Nm3/hr的氣化站，在系統(tǒng)火用效率最大的工況下，回收LNG位冷能用于發(fā)電每年的凈效益可達(dá)到60.3萬元，回收LNG冷能用于冰蓄冷空調(diào)，每年的節(jié)電效益約1078萬元，總共經(jīng)濟效益約為1138萬元。
[Abstract]:Liquefied natural gas (LNG) is a natural gas after desulphurization treatment. When liquefied natural gas is frozen and liquefied by cryogenic process, when it is used as fuel for downstream users, it will release a large amount of cold energy, about 830kJ / kg. In the traditional process, This part of cold energy is taken away by sea water or air, which not only causes the waste of energy, but also pollutes the environment. Therefore, it is of great theoretical and practical significance to fully recycle and utilize this part of cold energy. At present, the cold energy recovery and utilization of LNG is faced with a tight supply of resources. The spot price and long-term contract price fluctuate sharply. The construction of the cold energy utilization project is slow, and the mode of cold energy utilization is single. The problems of inefficient utilization and the unsynchronization of cold energy users with cold energy supply have hindered the large-scale development of LNG cold energy industry. Combined with the advantages of LNG cold energy used in power generation and ice storage air conditioning supply living area, according to the exergy analysis of LNG cold energy utilization and the trend change analysis of working medium and LNG variable temperature curve, the recovery of LNG high grade cold energy for power generation is put forward in this paper. Low-grade cold energy used in ice storage air-conditioning stage recycling process. By using the process simulation technology and exergy analysis method, the exergy efficiency of the key equipment with different flow rates was compared, and the optimal system parameters were selected, that is, the glycol aqueous solution with mass concentration of 32% was the working medium for ice storage air conditioning. If a mixture of propane and butane is used as an organic mixed working medium in the power generation process, The optimum mixing ratio is 50- 50% propane-butane (mass fraction), when the LNG flow rate is 1000kg / h, the optimum flow rate of the mixture is 1270 kg / h, the evaporation temperature is 10 鈩

本文編號：1883233