Carbon-dioxide-combined-type heat pump hot water and air conditioning system and control method thereof

Abstract

The invention discloses a carbon-dioxide-combined-type heat pump hot water and air conditioning system and a control method thereof. The system consists of a carbon dioxide heat pump unit, a freon circulation unit and a water storage box, wherein the carbon dioxide heat pump unit adopts carbon dioxide as a refrigerating agent and forms a first heat pump circulation loop; and the freon circulation unit adopts freon as a refrigerating agent, and a gateable second heat pump circulation loop, a heat pump and refrigeration circulation loop and a refrigeration air conditioning circulation loop are formed by utilizing a four-way valve and each switching valve. By adopting the carbon-dioxide-combined-type heat pump hot water and air conditioning system and the control method thereof, different working modes of heating, cooling and hot water supplying can be realized in a wide temperature zone in the whole year; and stable, reliable and energy-saving operation of the system is ensured.

Description

technical field [0001] The invention relates to the technical field of refrigeration and air conditioning, and in particular to a heat pump hot water and air conditioning system combined with a carbon dioxide heat pump unit and a Freon heat pump air conditioning unit and a control method thereof. Background technique [0002] Coal-fired heating and domestic hot water are widely used in North China and northern regions in winter. Coal-fired coal produces a large amount of dust and sulfur dioxide and other harmful gases. It is imminent to use clean heating and domestic hot water production methods. Air energy heat pumps are characterized by their high efficiency and environmental protection Factors such as friendliness and ease of use are valued, especially in rural areas without central heating. [0003] Conventional air energy heat pumps use freon refrigerants, which are restricted by their thermophysical properties. At temperatures below -15°C, the heating capacity and heat...

AI Technical Summary

Problems solved by technology

[0003] Conventional air energy heat pumps use freon refrigerants, which are restricted by their thermophysical properties. At temperatures below -15°C, the heating capacity and heating efficiency are seriously attenuated, which cannot meet the needs of indoor thermal comfort and domestic water temperature.

Carbon dioxide is a natural and environmentally friendly refrigerant with good thermal characteristics and high heat transfer coefficient. It has high thermal efficiency and high outlet water temperature when used in heat pumps. However, it has disadvantages such as low thermal efficiency and high system pressure during cooling in summer.

However, the absorption heat pump unit is not suitable for home heating due to its large size and low efficiency, and its cost-effectiveness and commercialization are not good

[0006] Chinese invention patent CN201510355069.0 discloses a carbon dioxide heat pump heating device, but due to the limitation of carbon dioxide thermal characteristics, it is not suitable for air conditioning in summer

[0007] Chinese invention patent CN201610832626 discloses a solar heat pump hot water system and method, which is also limited by the intensity and duration of sunlight, and can only prepare hot water, with a single function

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