Due to global warming, climate anomalies and other environmental problems are becoming more and more serious, environmental protection and energy saving has become one of the focus issues of the whole international community. In recent decades, the refrigeration and air conditioning industry has been using a large number of CFCs and HCFCs refrigerants, causing a hole in the ozone layer and the greenhouse effect, which has been widely recognized. HFCs have become an important substitute for CFCs because they are not destructive to the ozone layer. However, they are chemically stable and can accumulate after release, which eventually leads to significant greenhouse effect.
CO2 can play an important role in the field of automobile air conditioning and heat pump because of its good environmental characteristics, excellent heat transfer characteristics and considerable cooling capacity per unit volume, etc. The research and application of CO2 refrigeration devices has once again become a hot spot that is valued worldwide. Especially in the 1990s, since the former president of the International Institute of Refrigeration, G. Lorentzen, proposed the use of CO2 as an environmentally friendly refrigerant and the theory of trans-critical cycle, the advantages of CO2 in terms of environmental protection and performance have attracted more and more attention of the industry research, and the development of its systems and components has been greatly developed.
CO2 is the most environmentally friendly refrigerant other than water and air, and with an ODP of 0 and GWP of 1, CO2 is the second most environmentally friendly substance in the industrial field after water and air. Moreover, CO2 as a refrigerant, whether extracted naturally or from industrial waste gas, helps reduce greenhouse gas emissions.
CO2 has a number of unique properties.
Good safety and chemical stability, non-flammable, no harmful gas decomposition even at high temperatures, adaptable to a variety of lubricants and common mechanical component materials.
High cooling capacity per unit volume, which can reduce the size of refrigeration systems and heat pump equipment.
Excellent flow characteristics, low dynamic viscosity, small pressure drop loss of equipment.
Excellent heat transfer characteristics, large thermal conductivity, good heat transfer effect.
High energy efficiency ratio of ultra-low temperature heat pump.
The compression ratio of CO2 refrigeration cycle is lower than that of conventional mass refrigeration cycle, and the volumetric efficiency of the compressor can be maintained at a high level.
The KingClima CO2 heat pump bus air conditioner, which is now technically mature and has been installed and applied, has shown great technical comparative advantages in the market.
KingClima bus hvac systems
are truly green air conditioners.
Lower environmental adaptability, ultra-low temperature working temperature can reach -30°C stable and continuous work.
Adopt fully hermetic carbon dioxide special inverter compressor, suitable for lower ambient temperature.
The whole machine is matched with high-pressure resistant indoor and outdoor heat exchangers suitable for carbon dioxide work, and adopts brushless evaporation and condensation fans with reliable performance.
Independently developed electronic expansion valve and compressor frequency control system with dual control logic of superheat degree and optimal pressure.
Control the air conditioner into the defrost time according to the temperature interval, more accurate.
Using internal heat exchanger to improve system energy efficiency and make system operation more stable.
The air conditioning solutions for buses
are equipped with remote monitoring capability, which can remotely monitor the operation status of the air conditioning system and identify the system fault detection capability in advance to ensure normal operation of the air conditioner.
People want refrigerants to be environmentally friendly, efficient and economical, but in reality there is no perfect refrigerant. Compared with other refrigerants, CO2 has obvious advantages in terms of environmental protection, safety, economy and performance per unit volume of refrigeration capacity. Current research shows that the safety and reliability of CO2 system operation can be ensured by reasonable selection of pipe and tube wall thickness, and the reasonable improvement of CO2 cross-critical cycle can effectively reduce throttling loss and improve the cycle efficiency of the system. It is reasonable to believe that KingClima CO2 heat pump air conditioners with environmentally friendly refrigerants will have an increasingly good application prospect.