杨俊兰,李金芮,白杨,姬旭
YANG Junlan,LI Jinrui,BAI Yang,JI Xu

• 1:天津城建大学能源与安全工程学院

摘要(Abstract)：

为了比较回热器对不同型式CO_2热泵系统性能的影响,建立了5种带回热器CO_2跨临界循环的热力学模型,分析了吸气过热度、蒸发温度、高压压力和气体冷却器出口温度对制冷、制热系数的影响,以及蒸发温度、气体冷却器出口温度对最优高压压力的影响,给出了不同循环的适用条件。结果表明:带膨胀机单级、双级压缩系统综合性能较好,制冷COP可分别达到2.83和3.2,制热COP可分别达到3.82和3.6,但都不适合加回热器;回热器对CO_2跨临界双级带节流阀回热器循环(TSCV+IHE)性能提高最大,过热度平均每提升5 ℃,COP提升约0.1;CO_2跨临界单级带喷射器回热器循环(SCEJ+IHE)适用于蒸发温度、气体冷却器出口温度均较低的情况;单级压缩比双级压缩的最优高压压力低0.5～1 MPa;提高蒸发温度和减小气体冷却器出口温度都有利于降低最优高压压力。研究成果可为CO_2跨临界循环的性能提高和优化提供参考。
In order to compare the effects of internal heat exchanger on the performance of different types of CO_2 heat pump systems，five thermodynamic models of CO_2 transcritical cycles with internal heat exchanger were established.The effects of the suction superheat，evaporation temperature，high pressure and outlet temperature of the gas cooler on cooling and heating coefficients and the effects of evaporation temperature and outlet temperature of the gas cooler on the optimal high pressure were analyzed.The applicable conditions of different cycles were given.The results indicate that the performance of single-stage and two-stage compression systems with expander is the best，the COP_c can reach 2.83 and 3.2 respectively，and the COP_h can reach 3.82 and 3.6 respectively，but they are not suitable to be added with the internal heat exchanger；the internal heat exchanger is the most helpful for improving the performance of the TSCV+IHE，for every 5 ℃ increase in superheat，COP increases by about 0.1；The SCEJ+IHE is suitable for low evaporation temperature and low outlet temperature of the gas cooler；The optimal high pressure of single-stage compression system is 0.5～1 MPa lower than that of two-stage compression system；Increasing the evaporation temperature and reducing the outlet temperature of the gas cooler are beneficial to reduce the optimal high pressure.The research results can provide a reference for the optimal design of CO_2 transcritical cycle system.

关键词(KeyWords)： CO_2;跨临界循环;回热器;性能系数;最优高压压力
CO_2;transcritical cycle;internal heat exchanger;coefficient of performance;optimal high pressure

Abstract:

Keywords:

基金项目(Foundation): 天津市自然科学基金项目（17JCZDJC31400）

作者(Author): 杨俊兰,李金芮,白杨,姬旭
YANG Junlan,LI Jinrui,BAI Yang,JI Xu

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