Research On Comfort And Economic Of CO₂Heat Pump In Lanzhou

The CO2heat pump is one kind of the air source heat pumps. It uses CO2as its freezingmedium to accomplish the refrigeration or heating efficiency and makes good use of energyby using the low grade energy. The CO2heat pump has much more advantages than otherrefrigerating or heating system. People begin to pay wide attention to the CO2heat pump forsuch advantages as energy saving and little harm to the environment.However, there are still some problems in extending its practical use because theapplication of the air source heat pump is influenced by geography, climate and so on. Sothere is some difficulty in extending its use. Considering the factors above, here we mainlystudy the applicability of the heat pump to Lanzhou area in two such ways as the refrigeratingor heating efficiency. And basing on all the index, we will try instructing its use in Lanzhouarea.We have done some analyzation of CO2which is used as freezing medium for itsinfluences on environment, security, thermophysical property, compressor efficiency andother factors. By analyzing the advantages and disadvantages of CO2, it comes to us thatCO2has unique advantages as a kind of freezing medium. We have also put forward severalpatterns to improve cycle efficiency by analogue simulating its transcritical cycle in the airconditioning refrigeration mode, by changing evaporating temperature in cycle process andchanging temperature of gas cooler outlet. The optimal high side pressure is also in theconsideration and analyzation for the system efficiency index.Taking a certain workshop in Lanzhou as a target, we are studing the wide application ofthe CO2heat pump in Lanzhou area. First we learn about the geographical environment andclimatic environment of Lanzhou from the documents and then we choose typical rooms to doCFD simulation. We analyze the index of the room temperature, wind speed, air age andPWV-PPV.in the typical room in summer and winter while the air conditioner is on operation.The result shows that the CO2heat pump can meets standards of comfortable air conditionersand that the CO2heat pump is more energy saving than other heat pumps in early winterequipment investment and operation expenses.From a series of analyzation and comparation we can draw the conclusion that it is notonly practical but also energy saving to use the CO2heat pump air conditioner in Lanzhouarea. The study result gives theoretical direction of the wide use of CO2heat pumps inLanzhou area and other similar areas of the country.