摘要: |
本文对制冷工况下,单级跨临界二氧化碳(CO2)带膨胀机循环、跨临界CO2双级压缩无回热器循环、跨临界CO2双级压缩加回热器循环、跨临界CO2双级压缩一级节流无回热器循环和跨临界CO2双级压缩一级节流加回热器循环五种循环的性能进行了分析比较。结果表明:当膨胀机的效率为60%时,在所规定的蒸发温度范围内(﹣10 ℃~20 ℃),单级跨临界CO2带膨胀机循环的性能要高于其它四种双级压缩循环。当蒸发温度为5 ℃时,只要膨胀机的效率大于32%,单级压缩膨胀机循环的性能就高于其它四种双级压缩循环。对于四种双级压缩循环,前两种循环适用于中高温制冷,且回热循环性能较好;后两种带中间冷却器的循环适宜于中低温制冷,增加回热器后性能反而下降。 |
关键词: 膨胀机 CO2 跨临界循环 双级 单级 |
DOI: |
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Thermodynamic Analysis of One Kind of Single-stage with Expender and Four Kinds of Two-stage Transcritical Carbon Dioxide Refrigeration Cycle |
Sun Zhili1, Ma Yitai2
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(1.Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce;2.Institute of Thermal Energy Research, Tianjin University) |
Abstract: |
The performances of single-stage transcritical CO2 cycle with expander, transcritical CO2 two-stage cycle without intermediate heat exchanger, transcritical CO2 two-stage cycle with intermediate heat exchanger, transcritical CO2 two-stage & primary throttling cycle without intermediate heat exchanger and transcritical CO2 two-stage & primary throttling cycle with intermediate heat exchanger are analyzed in refrigeration condition. The results show that the single-stage expander cycle outperforms the other options when the expander efficiency is 60% at the given evaporation temperature (﹣10 ℃~20 ℃). When the evaporation temperature is 5 ℃ and the expander efficiency is greater than 32% , the performance of expander cycle is the best. In the other four two-stage cycles, transcritical CO2 two-stage cycle without intermediate heat exchanger and transcritical CO2 two-stage cycle with intermediate heat exchanger are reasonable options in medium and high evaporation temperature, and the performance of using internal heat exchanger in cycle is much better; transcritical CO2 two-stage & primary throttling cycle without intermediate heat exchanger and transcritical CO2 two-stage & primary throttling cycle with intermediate heat exchanger are more applicable to medium and low evaporation temperature. And the using of internal heat exchanger decreases the cycle performance. |
Key words: expender carbon dioxide transcritical cycle two-stage single-stage |