Proposal and assessment of a new integrated liquefied natural gas generation process with auto – Cascade refrigeration (exergy and economic analyses)
Proposal and assessment of a new integrated liquefied natural gas generation process with auto – Cascade refrigeration (exergy and economic analyses)
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DOI：
10.1016/j.seta.2020.100728
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发表时间：
2020-08
影响因子：
8
通讯作者：
M. Mehrpooya;B. Ghorbani;S. Mousavi;A. Zaitsev
中科院分区：
文献类型：
--
作者：
M. Mehrpooya;B. Ghorbani;S. Mousavi;A. Zaitsev
本研究的主要目的是提出一种新的液化天然气（LNG）生产工艺，使用自动复叠制冷作为预冷系统。该自动级联系统独立运行（无需外部电力），可提供−54.62 °C的制冷温度，从而降低工艺的总耗电量。采用白杨HYPERV 11软件对该复合工艺进行了模拟。通过能量分析，该工艺可生产31.71 kg/s的LNG，比功率为0.189 kWh/kg LNG。为了从技术上对系统进行评估，对系统的各个子单元和整个过程进行了分析。评价结果表明，该装置的总效率为91.68%，总损火用率为67688 kW。此外，约77.3%的整体不可逆性发生在热交换器。这一过程的经济方面是由系统（ACS）方法的年化成本进行评估。根据经济评估结果，产品的年化成本和主要成本分别为182.6 MMUS$/年和0.1959 US$/kg LNG。在继续，拟议的配置的技术和经济产出进行了比较，以前的调查。结果表明，采用自复叠制冷系统作为LNG生产的预冷系统，可显著降低LNG生产所需的动力和一次成本。最后，为了明确经济因素对电价的影响，进行了敏感性分析。此外，研究了涡轮机进口压力对混合过程效率的影响。
The main objective of this study is to propose a novel Liquefied Natural Gas (LNG) production process using the auto – cascade refrigeration as the pre-cooling system. This auto – cascade system operates as stand-alone (without external electricity), and can supply the refrigeration temperature of −54.62 °C, which can decrease the total electricity consumption of the process. The Aspen HYSYS V11 software is employed for simulation of this hybrid process. Based on the energy analysis, this integrated process can produce 31.71 kg/s LNG by consuming the specific power of 0.189 kWh/kg LNG. In order to evaluate the system technically, the exergy analysis is implemented for each subunit and the whole process. The outcomes of exergy evaluation depicted that the overall exergy efficiency and overall destroyed exergy rate are 91.68% and 67688 kW, respectively. Also, about 77.3% of the overall irreversibility occurred in the heat exchangers. The economic aspect of this process is evaluated by the Annualized Cost of System (ACS) method. Based on the outcomes of economic assessment, the annualized cost and prime cost of product are accounted for 182.6 MMUS$/year and 0.1959 US$/kg LNG, respectively. In continue, the technical and economic outputs of the proposed configuration are compared to the previous investigations. It was found that by utilizing the auto – cascade refrigeration system as the precooling system of LNG production, the required power and primary costs for producing LNG are considerably reduced. Finally, in order to specify the effects of economic factors on the electricity price, the sensitivity analysis is implemented. Furthermore, the influence of turbine inlet pressure on the efficiency of the hybrid process is investigated.