Heat pump air conditioning system

Abstract

The invention discloses a heat pump air conditioning system, which comprises a compressor, an evaporation system, a condenser and a four-way reversing valve. The condenser and the evaporation system are communicated with each other by a cooling exchange pipeline and a heating exchange pipeline; the evaporation system comprises a high-temperature evaporator connected with the cooling and heating exchange pipelines; the high-temperature evaporator is connected with a low-temperature evaporator of the evaporation system by an economizer; a second cooling throttle valve and a second heating throttle valve are connected in series between the economizer and the low-temperature evaporator; a heating check valve and a cooling check valve are connected in parallel on the second cooling throttle valve and on the second heating throttle valve respectively; an air outlet on the economizer is communicated with a middle return air inlet of the compressor; the heating fluid outlet of the economizer is connected with the cooling and heating exchange pipelines; and a second heating branch is arranged between a pipeline of the low-temperature evaporator communicated with the four-way reversing valve and an inlet end of the high-temperature evaporator. Being more economical and environmental protecting, the heat pump air conditioning system can greatly improve the cooling performance of the heat pump, improve the quality of the indoor air treatment and save energy.

Description

technical field [0001] The invention relates to the field of heating, ventilating and air conditioning, in particular to a heat pump air conditioning system. Background technique [0002] In air conditioning engineering, indoor temperature and humidity are two important parameters that affect thermal comfort and need to be controlled. In the current air-conditioning project, the method of cooling is mainly used to reduce the temperature and dehumidify. The independent fresh air system is a new HVAC technology that has developed rapidly in recent years. In comfort air conditioning, sensible heat usually accounts for the main part of the load, while latent heat (humidity load) accounts for a minority. By treating the heat and humidity loads separately, the evaporation temperature of the refrigerator can be increased during operation, thereby improving the efficiency, while the humidity load can be borne by the fresh air that has been treated to a low humidity content, elimin...

AI Technical Summary

Problems solved by technology

However, the principle of thermodynamics determines that the performance of the heat pump is affected by the temperature of the cold and heat source when it is working. The air source heat pump uses the external ambient air as its cold and heat source, and its performance is not only affected by the external ambient temperature, but also by the cold and heat source output to the indoor end. It is related to the temperature level, and the impact of ambient temperature is opposite to the trend of heating and air conditioning load changes: in winter, the temperature drops and the heating load of the house increases, but the heating capacity of the heat pump decreases with the temperature drop, the performance deteriorates, and the temperature drops to To a certain extent, conventional air source heat pumps can’t even work normally; in summer, when the temperature rises, the air conditioning load increases, but the cooling capacity of the heat pump decreases with the increase of temperature, and the performance also deteriorates

[0004] In addition, the current heat pump technology mainly adopts the convective heat exchange method on the indoor use side. In summer, when the air conditioner is cooling, in order to maintain and control the indoor temperature and humidity, the cooling method is used to cool down and dehumidify the room so that it is in the thermal comfort zone of the human body. It is necessary to reduce the evaporation temperature of the heat pump, thereby affecting the performance of the heat pump, and the condensed water produced by cooling and dehumidification will also bring about indoor air quality problems and affect people's health; when heating in winter, the supply air temperature that meets the thermal comfort requirements of the human body should not be too low. As a result, the heat pump is required to maintain a high condensing temperature and pressure, which will also reduce its heating performance

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