摘要
针对传统分析方法只能找到有效能损失的关键设备而无法找到其损失的主要源由的不足,提出了改良的?分析方法。为了提高LNG冷能用于空气分离工艺的效能,基于大连LNG接收站的基础数据,利用HYSYS软件对提出的LNG冷能空分工艺进行模拟,对传统?和改良?进行分析计算,研究了主要设备各类?损的分布情况,找到了引起各设备有效能损失的主要原因,并基于改良?分析结果进行工艺优化。研究结果表明:(1)?损失可划分为可避免内源性损失、可避免外源性损失、不可避免内源性损失和不可避免外源性损失4个部分;(2)各个压缩机的?损分布情况较类似,可避免的内源性?损均占较大比例;(3)不同换热设备的?损区别较大,LNG-104、E-100、E-101主要为可避免外源性?损,其他换热设备主要为不可避免内源性?损;(4)水冷器E-100和E-101的可避免外源性?损占比很大;(5)针对改良的?分析结果提出了更换压缩机、增加冷流、增加预冷设备等为优化方向的两种优化方案,优化方案的单位液态产品能耗和有效能利用率较原方案均有所改善,对比分析后优选了优化方案二——方案二的能耗约为0.394 9 kWh/kg(降低了6.6%)、有效能利用率约为0.40(提高了28.891%)。结论认为,优化结果验证了在LNG冷能空分工艺中采用改良?分析优化方法的可行性,为实际工程中空分工艺的优化开辟了一条新的技术思路。
By virtue of the traditional exergy analysis method,only the key equipments with exergy loss can be identified while the main causes of the loss cannot be found out.In this paper,an advanced exergy analysis method was proposed to solve the defect of the traditional one.Firstly,based on the basic data of the Dalian LNG receiving station,the proposed air separation process of LNG cold energy was simulated by using the software HYSYS.Then,the traditional exergy and the advanced one were calculated and analyzed.The distribution of various exergy loss in main equipments was analyzed and the main reasons for the exergy loss were figured out.Finally,the process was optimized on the basis of the advanced exergy analysis results.And the following research results were obtained.First,the exergy loss can be divided into four parts,i.e.,avoidable endogenous loss,avoidable exogenous loss,unavoidable endogenous loss and unavoidable exogenous loss.Second,the distribution of exergy loss in different compressors is similar and the proportion of avoidable endogenous loss is higher.Third,the exergy loss of different heat exchanging devices is different.The avoidable exogenous exergy loss is dominant in the heat exchanging devices of LNG104,E100 and E101 while the unavoidable endogenous exergy loss is dominant in the other heat exchanging devices.Fourth,the proportion of avoidable exogenous exergy loss is higher in the water coolers of E100 and E101.Fifth,based on the advanced exergy analysis results,two optimization schemes are put forward in respect to replacing compressor,increasing cold flow and increasing pre-cooling equipment.Compared with the original scheme,the energy consumption and exergy utilization ratio of unit liquid product in the two optimization schemes are better.Based on comparative analysis,Scheme 2 is selected,and its energy consumption is about 0.3949 kwh/kg(decreased by 6.6%)and its exergy utilization ratio is about 0.40(increased by 28.891%).In conclusion,the optimization results prove the feasibility of applying the advanced exergy analysis method in the air separation process of LGN cold energy.The research results provide a new technological idea for the optimization of air separation process in actual engineering.
作者
马国光
李雅娴
张晨
Ma Guoguang;Li Yaxian;Zhang Chen(School of Oil&Natural Gas Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2018年第9期121-128,共8页
Natural Gas Industry
关键词
改良分析
传统分析
LNG冷能
空气分离
损失
效率工艺优化
Advanced exergy analysis
Traditional exergy analysis
LNG cold energy
Air separation
Exergy loss
Exergy efficiency
Process optimization
