A parallel flow evaporator carbon dioxide system and method of operation thereof

Abstract

The invention discloses a parallel flow evaporator carbon dioxide system, comprising: a compressor, a gas cooler, an intermediate heat exchanger, an electronic expansion valve, a liquid storage device and an evaporator; the exhaust port of the compressor is connected to the inlet of the gas cooler; The outlet of the gas cooler is connected to the inlet of the a-end of the intermediate heat exchanger, and the outlet of the b-end of the intermediate heat exchanger is connected to the inlet of the electronic expansion valve; the outlet of the electronic expansion valve is connected to the inlet of the liquid receiver; the gas outlet of the liquid receiver is connected to the middle The inlet of the c-end of the heat exchanger and the outlet of the d-end of the intermediate heat exchanger are connected to the outlet of the evaporator; the liquid outlet of the liquid receiver is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the suction port of the compressor. The gas-liquid flow rate and dryness of the refrigerant entering the parallel flow evaporator can be adjusted, the heat transfer performance of the parallel flow evaporator is improved, and thus the cycle performance of the transcritical cycle is improved. The problem that the uneven distribution of the gas-liquid two phases among the flat tubes in the parallel flow evaporator leads to a significant decline in heat transfer performance is solved.

Description

technical field [0001] The invention belongs to the field of transcritical carbon dioxide systems, in particular to a parallel flow evaporator carbon dioxide system. Background technique [0002] As we all know, synthetic refrigerants such as CFCs and HCFCs are one of the main factors leading to global warming. Therefore, finding and using efficient, green and environmentally friendly refrigerants has become a common concern of the international community and is urgent. Natural working fluid CO 2 As an alternative working fluid, it is not only environmentally friendly but also has excellent performance. The high exhaust temperature and temperature glide of its transcritical cycle make it have incomparable advantages in the application field of heat pump water heaters compared with other known working fluids. G Lorentzen, former president of the International Institute of Refrigeration, proposed the CO 2 The transcritical cycle theory points out that it will have extremely ...

AI Technical Summary

Problems solved by technology

The distribution of the gas-liquid two phases (especially the liquid phase) among the flat tubes in the parallel flow evaporator has a great influence on its heat transfer performance. If the gas-liquid distribution between the flat tubes is uneven, the heat transfer performance will be significantly reduced. , if the pure liquid refrigerant enters the parallel flow evaporator, the liquid separation in the evaporator is uniform, and the heat transfer efficiency is good; It affects the heat exchange effect of the heat exchanger and reduces the cycle performance of the system

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