CO2 heat pump device

Abstract

The invention discloses a CO2 heat pump device. The CO2 heat pump device comprises a compressor, a gas cooler, an oil heat exchanger, a first filter, a throttling device, an evaporator and a gas-liquid separator which are sequentially connected to a main heating circulation pipeline. The CO2 heat pump device further comprises an ice melting circulation pipeline, the compressor, a third filter, a second electromagnetic valve, the evaporator and the gas-liquid separator, wherein the compressor, the third filter, the second electromagnetic valve, the evaporator and the gas-liquid separator are connected to the ice melting circulation pipeline. When the bottom of the evaporator is frozen, the second electromagnetic valve is switched on, high-temperature and high-pressure CO2 gas enters an independent pipeline on the lower portion of the inside of the evaporator via the third filter and the second electromagnetic valve from an outlet of the compressor, an ice layer at the bottom of the evaporator can be molten, then generated heat CO2 steam returns to a gas return opening of the compressor via the gas-liquid separator, and thus ice melting circulation of the CO2 heat pump device can beformed. The CO2 heat pump device can operate at a low environment temperature, rapid ice melting can be achieved and heating operation of the system is made stable.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to CO 2 heat pump unit. Background technique [0002] CO 2 Heat pump technology uses natural CO 2 As a circulating working fluid, it adopts a transcritical circulation method to release heat under supercritical conditions. The heat release is a variable temperature process with a large temperature glide, which matches the required variable temperature heat source very well. It is a special kind of Lorenz cycle. [0003] CO 2 When heat pumps are used in low-temperature areas, there will always be frosting, especially in extremely cold areas. Due to the low temperature, the water after defrosting in the evaporator cannot flow away in time. Freezing, the ice layer will affect the heating capacity of the heat pump system. In the prior art, it has been proposed to introduce the outlet of the gas cooler into the subcooling section and go to the bottom of the evaporator to p...

AI Technical Summary

Problems solved by technology

[0003] CO 2 When heat pumps are used in low-temperature areas, there will always be frosting, especially in extremely cold areas. Due to the low temperature, the water after defrosting in the evaporator cannot flow away in time. Freezing, the ice layer will affect the heating capacity of the heat pump system

In the prior art, it has been proposed to introduce the outlet of the gas cooler into the subcooling section and go to the bottom of the evaporator to prevent freezing, but in a low temperature environment, the temperature of the inlet water is usually relatively low, and the CO 2 There is a large temperature glide in the heat exchange in the gas cooler, so that the gas cooler outlet CO 2 The temperature of the refrigerant and the inlet water is close to or slightly higher than that of the fluorine refrigerant, which has a higher outlet condensation temperature, and the outlet CO 2 After the refrigerant exchanges heat with the inlet water, the gas cooler exports CO 2 The temperature difference between the refrigerant and the ice layer is actually small, and the ice melting effect is average

Images