Low-temperature non-stop heat pump air-conditioning system and control method thereof

Abstract

The invention relates to the technical field of air conditioners, in particular to a low-temperature non-stop heat pump air-conditioning system. The low-temperature non-stop heat pump air-conditioningsystem comprises a condenser, a throttling device, an evaporator and a compressor. An outlet of the compressor is connected with an inlet of the compressor through the condenser, the throttling device and the evaporator in sequence to form a heat pump loop. The low-temperature non-stop heat pump air-conditioning system is characterized by further comprising a high and low-pressure bypass device used for regulating the differential pressure of the heat pump loop; compared with the prior art, the high and low-pressure bypass device is connected with the two working ends of the compressor in parallel; the differential pressure of the two ends of the compressor is balanced through the high and low-pressure bypass device, and it is ensured that the compressor still can operate normally under the condition of the excessive low environment temperature. The problem that the cost is increased due to the fact that other heating equipment needs to be additionally input for auxiliary heating is solved. The unit structure is simplified. The invention further provides a control method of the low-temperature non-stop heat pump air-conditioning system.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a low-temperature non-stop heat pump air conditioning system and a control method thereof. Background technique [0002] The traditional air energy heat pump heating / heating air conditioning system is mainly composed of compressor 1, evaporator 5, condenser 3, throttling device 4, and four-way valve 2, as shown in the attachment figure 1 As shown in the traditional air energy heat pump system, when the system is heating, the high-pressure and high-temperature refrigerant heat discharged by the compressor 1 is released to the use side in the condenser 3, and the refrigerant becomes a low-temperature and low-pressure two-phase state after being throttled by the throttling device 4 , absorb the heat in the air in the evaporator 5 to become a superheated gas, and then return to the compressor 1 for compression, thus completing the heating cycle. [0003] At present, among t...

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Problems solved by technology

[0003] At present, among the solutions to environmental pollution caused by coal burning in the north, air source heating is becoming an optimal solution, but at the same time, facing the phenomenon of low ambient temperature in winter in the north, the scope of use of compressors has become a limitation of air source heat pumps. Important factors: the lower the ambient temperature, the more difficult it is for the air-cooled evaporator to absorb heat, the lower the low-pressure pressure of the compressor, and the compressor evaporation temperature exceeds the designed operating range of the compressor and there is a limit or protection (the evaporation temperature is too low to form enough The low-pressure evaporating gas cannot reach the low pressure limit for compressor startup), and the low-pressure pressure of the heat pump circuit is too low, which eventually leads to the failure of the unit to operate normally at low ambient temperature

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