| 摘要: |
| 在碳中和背景下，天然工质CO2在制冷及制热应用中受到日益广泛的关注。本文采用夹点分析理论，对人工冰场的CO2制冷及热回收系统中双级热回收结构进行了优化分析。在假设两级串联热回收（低温热回收进出口水温为40 ℃和60 ℃，高温级进出口水温为60 ℃和80 ℃）的情况下，通过改变某一级的水质量流量，得出以下分析结果：夹点的存在会升高热回收换热器的CO2出口温度，降低系统的热回收量、制热性能系数以及综合COP，同时对应于最大COP的最佳排气压力也会后移，直至超出上限（当第二级质量流量比为0.4时，可通过调节第一级质量流量比来消除夹点的影响；而第一级质量流量比为0.4时，最佳排气压力会由10.2 MPa升至10.9 MPa，同时最大综合COP由3.538降至2.843）；为了尽量提升系统性能，应当在合理范围内，降低第二级水质量流量，提高第一级水质量流量，同时提高排气压力。 |
| 关键词: 人工冰场 制冷热回收系统 夹点分析 CO2 性能系数 |
| DOI： |
| Received:March 07, 2022Revised:April 22, 2022 |
| 基金项目:国家重点研发计划(2019YFF0301504)和国家自然科学基金 (52076085) 资助项目。 |
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| Optimization Analysis of CO2 Refrigeration and Heat Recovery System for Ice Rink Based on Pinch Point Theory |
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Zhou Xiaohu1, Geng Xudong1, Li Feng2, Si Chunqiang2, Ma Jin2, Shao Shuangquan1
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| (1.School of Energy and Power Engineering, Huazhong University of Science and Technology;2.Huashang International Engineering Co., Ltd.) |
| Abstract: |
| Against the backdrop of carbon neutralization, CO2 has attracted increasing attention as a natural working medium for refrigeration and heating applications. Based on pinch point analysis, a CO2 refrigeration and heat recovery system for an ice rink is optimized and analyzed. Under the assumption of two-stage heat recovery (water temperatures at the inlet and outlet are 40 °C and 60 °C for low-temperature heat recovery and 60 °C and 80 °C for high-temperature heat recovery), the following results were obtained by changing the water mass flow rate at a specific stage. The existence of the pinch point increased the CO2 outlet temperature for heat recovery in the heat exchanger and reduced the amount of recovered heat, heating coefficient of performance (COPh), and comprehensive COP of the system. The optimal discharge pressure corresponding to the maximum COP also moved backward until it exceeded the upper limit. When the mass flow ratio of the second stage is 0.4, the influence of the pinch point can be eliminated by adjusting the mass flow ratio of the first stage. When the mass flow ratio of the first stage is 0.4, the optimal discharge pressure increased from 10.2 to 10.9 MPa, while the maximum comprehensive COP decreased from 3.538 to 2.843. To improve the system performance, the mass flow rate of water at the second and first stages should be decreased and increased, respectively, while the discharge pressure should be increased within a reasonable range. |
| Key words: ice rink refrigeration and heat recovery system pinch point analysis CO2 coefficient of performance |
