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跨临界CO_2系统已成为热泵及空调领域的研究热点,本文以CO_2气冷器为研究对象,管内外两种流体因温差传热与流动阻力引起系统(火积)耗散,通过建立的CO_2气冷器跨临界区二维分布参数模型求解系统(火积)耗散数ΔE*。分析系统(火积)耗散数产生的主要原因及沿程分布,讨论CO_2、水入口状态参数对系统(火积)耗散数的影响。结果表明系统(火积)耗散数主要由温差传热引起,温差越大,系统(火积)耗散数越大。各微元段(火积)耗散数与CO_2温降幅度呈反比关系,在临界点ΔEj*达到最大值。随着CO_2质量流率、压力的增大,系统(火积)耗散数逐渐增大;随着水质量流量的增大,系统(火积)耗散数逐渐减小,减小幅度随着压力的增大而减小。系统(火积)耗散数随着CO_2入口温度的增大而减小,CO_2入口温度越大,减小幅度逐渐降低。水入口温度对系统(火积)耗散数的影响非常小。(火积)
The transcritical CO_2 system has become a hotspot in the field of heat pumps and air conditioners. In this paper, the CO_2 air cooler is taken as the research object. Due to the difference of heat transfer and flow resistance, the CO_2 system is dissipated by the CO_2 gas cooler. COMBINED TWO - DIMENSIONAL DISTRIBUTION PARAMETER MODEL FOR COLD - CRITICAL CRITICAL REGION. The main causes of the dissipation of system (Fire Product) and the distribution along the process are analyzed. The influence of CO_2 and water inlet parameters on the dissipation of the system (Fire Product) is discussed. The results show that the system (Fire Product) dissipation number mainly caused by temperature difference heat transfer, the greater the temperature difference, the greater the system (Fire Product) dissipation number. The dissipation of each micro-segment (Fire Product) is inversely proportional to the temperature drop of CO_2, and reaches the maximum at the critical point ΔEj *. With the increase of mass flow rate and pressure of CO_2, the dissipation of system (Fire Product) gradually increases. With the increase of water mass flow, the dissipation of system (Fire Product) decreases gradually with the increase of pressure. Pressure increases and decreases. The system (fire product) dissipation number decreases with the increase of CO_2 inlet temperature. The larger the CO_2 inlet temperature, the smaller the decreasing amplitude. The effect of the water inlet temperature on the system (fire product) dissipation number is very small. (Fire product)