| 摘要: |
| 为了提升燕气压缩式制冷/热泵装置的能效,提出了一种新循环一一梯级吸排气循环。通过设置数个具有一定梯度的吸排气压力,实现制冷剂对换热流体温度的梯形逼近,有效减小蒸发器与冷凝器的传热不可逆损失,同时降低循环压比。梯级吸排气循环的实际节能效果受多种因素影响,研究表明:换热流体温度变化幅度以及蒸发器与冷挺器传热能力强弱对其节能幅度 的影响超过6.5%;不合理的过冷度设计甚至会导致其丧失节能性。最后,本文基于实践案例对梯级吸排气循环在实际应用中的 节能效果进行介绍。 |
| 关键词: 制冷 热泵 节能 梯级吸排气循环 |
| DOI： |
| Received:December 14, 2020Revised:March 03, 2021 |
| 基金项目:国家自然科学基金(51676140)资助项目。 |
|
| Fundamentals and Applications of Stepped Pressure Cycle |
|
Cao Xiang1,2, Zhang Chunlu2
|
| (1.Postdoctoral Station of Mechanical Engincering, Tongji University;2.Institute of Refrigeration and Cryogenics，School of Mechanical Engineering， Tongji University) |
| Abstract: |
| A stepped pressure cycle is proposed to improve the energy efficiency of refrigeration and heat pump cycles. By constructing multiple suction and discharge pressures, the refrigerant temperatures in the evaporators and condensers underwent step changes and approached the heat source temperatures. This helps to improve heat transfer efficiency and reduce the compression ratio. However, we found that the conclusion of energy savings for the stepped pressure cycle is conditional. Over 6.5% of the energy-saving potential is reduced because of inefficient heat exchangers or a small temperature glide of the heat transfer fluid. Moreover, an excessive subcooling degree will lead to a worse COP than a simple cycle. Finally, in this study, some application cases are summarized to demonstrate the energy-saving potential of the stepped pressure cycle. |
| Key words: refrigeration heat pump enengy-saving stepped pressure cycle |
