Single-and-double-stage switchable heat pump

Abstract

The invention discloses a single-and-double-stage switchable heat pump and belongs to the field of heat pump systems. The heat pump comprises a low-pressure system, a high-pressure system and a main heat exchanger connected in parallel between the low-pressure system and the high-pressure system. A first compressor and a first heat exchanger are arranged in the low-pressure system and connected in series with a left side pipeline of the main heat exchanger. A second compressor and a second heat exchanger are arranged in the high-pressure system and connected in series with a right side pipeline of the main heat exchanger. According to the single-and-double-stage switchable heat pump, the low-pressure system and the high-pressure system are formed by single-stage heat pump bodies and connected in parallel through the main heat exchanger, single-stage heat pump refrigerating / heating circulation can be performed as long as the first compressor in the low-pressure system is independently turned on, and cascade heat pump heating operation can be achieved as long as the second compressor is firstly turned on and the first compressor is turned on afterwards. The heat pump system can be freely switched between the single-stage heat pump mode and the cascade heat pump mode, and therefore the purposes of fully utilizing the advantages of both the modes and effectively saving energy and reducing emissions are achieved.

Description

technical field [0001] The invention relates to a heat pump system, in particular to a single-stage and double-stage switchable heat pump. Background technique [0002] Although the ordinary cascade heat pump satisfies the needs of low-temperature heating and high-temperature hot water well, when the unit is in cooling operation, its cooling efficiency is not high, and it can only meet simple defrosting, but cannot meet the needs of high-efficiency cooling . Moreover, the heating efficiency of common cascade heat pumps is generally not high when the ambient temperature is between 0°C and 15°C for heating. The single-stage heat pump system has the advantages of high cooling operation efficiency and high ambient temperature heating and heating efficiency, so it is necessary to design a heat pump system that can freely switch between single-stage heat pump and cascade heat pump operation, which can meet the annual cooling and cooling requirements. heat on demand. Contents o...

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Problems solved by technology

[0002] Although the ordinary cascade heat pump satisfies the needs of low-temperature heating and high-temperature hot water well, when the unit is in cooling operation, its cooling efficiency is not high, and it can only meet simple defrosting, but cannot meet the needs of high-efficiency cooling

Moreover, the heating efficiency of ordinary cascade heat pumps is generally not high when the ambient temperature is between 0°C and 15°C for heating.

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