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| Abstract: |
| In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energy of liquefied natural gas (LNG) could be fully utilized as well. A system simulation and thermodynamic analysis were carried out, the Kalina cycle was reorganized by changing the concentration of “basic composition”, so that a better thermal matching in the heat exchanger could be obtained and the irreversibility of the system was decreased. It was found that the Kalina cycle generally used in the bottom of combined power cycle could also be used to recover the cold energy of LNG. The results show that the exergy efficiency of 42.97% is obtained. Compared with the previous system attained the exergy efficiency of 39.76%, the improved system has a better performance. |
| Key words: combined power system LNG (liquefied natural gas) cold energy Kalina cycle thermodynamic analysis |
| DOI：10.11916/j.issn.1005-9113.16135 |
| Clc Number:TK124 |
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| Descriptions in Chinese: |
| 一种改进的利用液化天然气冷火用的动力循环 王平，李佳星，沈胜强 （大连理工大学能源与动力学院海洋能源利用与节能教育部重点实验室） 创新点说明：在kalina循环的基础上，利用中高温热源，对分馏子系统进行了改进，改善了氨水工质和天然气在换热器中的换热情况，从而有利于LNG冷能的回收。 研究目的： 提高联合循环中底部循环的热效率和火用效率，并且在联合循环中合理利用LNG的冷火用 研究方法： 利用大型通用流程模拟软件Aspen Plus建立流程并模拟计算。 结果： 改进之后的循环获得了更高的热效率和火用效率。 结论： 新的循环相比于旧循环，系统的结构有所精简，在分析了系统中各个换热器的火用损失并对比两个循环之后，新循环的换热器中的火用损失有所减少。 中文摘要：通过对循环进行模拟和热力学分析，改进了一种动力循环，在该循环中燃气轮机排气的余热和液化天然气的冷能得到了很好的利用。在kalina循环的基础上，通过改变基础溶液的浓度，从而在换热器中获得了很好的换热匹配并且减少了系统的不可逆损失。研究表明：kalina循环可以用于液化天然气冷能的回收，改进之后的循环的火用效率为42.97%，相比于改进之前的火用效率39.76%，改进之后的系统有更好的热力学性能。 关键词：联合循环；液化天然气；冷能；kalina循环；热力学分析 |
