Thermodynamic performance and the exergy destruction of the transcritical CO2 two-stage compression and ejector expansion direct cooling ice making system
Thermodynamic performance and the exergy destruction of the transcritical CO2 two-stage compression and ejector expansion direct cooling ice making system
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DOI：
10.1016/j.ijrefrig.2023.03.027
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发表时间：
2023-04
影响因子：
3.9
通讯作者：
Wenlong Li;BAO-YAN Wang;Jianqiang Deng;Yang He
中科院分区：
文献类型：
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作者：
Wenlong Li;BAO-YAN Wang;Jianqiang Deng;Yang He
2022年北京冬奥会室内场馆首次采用跨临界CO2直接供冷技术。该技术具有结构紧凑、冰温均匀、节能环保等一系列优点。为了进一步降低能耗，提高性能，对两级压缩低压引射直冷制冰系统（TCLES）和两级压缩中压引射直冷制冰系统（TCIES）进行了研究。通过建立一维热力学模型对系统的性能进行了模拟。考虑了气体冷却器压力、气体冷却器出口温度、蒸发温度和中间压力对系统的影响。结果表明，在无热回收和有热回收的情况下，TCLES和TCIES各有优势;在仅考虑冷却性能的情况下，两级压缩比喷射器更能提高系统性能。在此基础上，对两个系统进行了常规火用分析和高级火用分析。先进的火用分析表明，两个系统的火用破坏主要是在低压和高压压缩机中可以避免的。此外，还讨论了气体冷却器压力对火用损特性的影响。当气体冷却器压力控制在9.0MPa时，压缩机和引射器可避免的内源火用损失，TCLES最大分别减少4.14%和13.92%，TCIES最大分别减少16.15%和28.04%。
The transcritical CO2direct cooling technology was used for the first time in the indoor venues of the 2022 Beijing Winter Olympic Games. The technology has a series of advantages, such as compact structure, uniform ice temperature, energy saving and environmental protection. In order to further reduce the power consumption and improve the performance, two-stage compression and low-pressure ejector direct cooling ice making system (TCLES) and two-stage compression and intermediate-pressure ejector direct cooling ice making system (TCIES) are studied. The performance of the systems is simulated by constructing a one-dimensional thermodynamic model. The impacts of the gas cooler pressure, gas cooler outlet temperature, evaporation temperature and intermediate pressure on these systems are considered. It is showed that TCLES and TCIES have their own advantages when the system is without and with heat recovery, and found that two-stage compression improves the system performance more than the ejector when only the cooling performance is considered. On this basis, conventional exergy and advanced exergy analysis of both systems are carried out. Advanced exergy analysis shows that exergy destruction can be avoided mainly in low-pressure and high-pressure compressors of both systems. Besides, the influence of gas cooler pressure on exergy destruction characteristics is discussed. When controlling the gas cooler pressure at 9.0 MPa, the avoidable endogenous exergy destruction of compressors and ejector is reduced by a maximum of 4.14% and 13.92% for TCLES and reduced by a maximum of 16.15% and 28.04% for TCIES.