Carbon dioxide direct extension air conditioning device

Abstract

The invention discloses a carbon dioxide direct extension air conditioning device, which comprises a compressor, a first heat exchange device, a second heat exchange device, a throttling device and a refrigerant pipeline, wherein the air conditioning device also comprises a steering valve; the refrigerant pipeline connects the compressor, the steering valve, the first heat exchange device, the throttling device and the second heat exchange device to form a sealed circulation loop; carbon dioxide refrigerants are filled in the refrigerant pipeline. The second heat exchange device comprises an air inlet, a second fin heat exchanger, a second fan and an air outlet in sequential grouped connection. The carbon dioxide direct extension air conditioning device provided by the invention has the advantages that during the heat supply in winter, the second fin heat exchanger directly performs heat exchange with indoor air or outdoor air; hot water does not need to be prepared at first; then, through the heat exchange between the hot water and the air, the heat exchange link is reduced; the heat supply structure is simplified; in addition, the air supply temperature is lower, so that the heat supply efficiency of the carbon dioxide air conditioning device can be greatly improved; the carbon dioxide direct extension air conditioning device is very suitable for large space warming.

Description

technical field [0001] The invention relates to a direct expansion air conditioner, in particular to a carbon dioxide direct expansion air conditioner. Background technique [0002] The critical parameters of carbon dioxide (critical temperature t c =31.06°C, p c =7377.65kPa) determines the way and basic characteristics of the carbon dioxide heat pump cycle. Due to its low critical temperature, it is restricted by the ambient temperature during cooling in summer and the temperature of hot water during heating in winter, which determines that when carbon dioxide is used in the field of heat pumps, a transcritical cycle should be used. Due to its transcritical cycle characteristics, it has performance beyond conventional Freon heat pumps in terms of heating and domestic hot water supply. At the same time, carbon dioxide is a natural working medium, and its effect on the destruction of the ozone layer and the accumulation of the greenhouse effect is almost negligible. [00...

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Problems solved by technology

[0003] At present, carbon dioxide air source heat pumps have also begun to be used for heating, but all heat pump units first produce hot water, and then the hot water is passed into end devices such as radiators, fan coil units, or air conditioning units, and heat is exchanged between wind and water. For heating, and the minimum return water temperature of all hot water heating methods is above 35°C, which exceeds the critical temperature of carbon dioxide working fluid. If the heating return water is directly passed into the carbon dioxide heat pump unit, the heating efficiency will be very low , or even difficult to operate. At present, some people try to solve the above problems in the following ways. One way is to install a water ring heat pump on the hot water side to reduce the return water temperature at the end to meet the inlet water temperature of the heat pump unit. Then enter the heat pump unit

Another way is to change the water ring heat pump into a heat exchanger, and exchange heat between the return pipe and the refrigerant pipe. The above two methods have very limited effect on improving the heating efficiency of the carbon dioxide heat pump unit.

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