The Optimization Research On The Multifunctional Heat Pump Air Conditioning System

Nowadays, energy crisis and environmental problems have been becoming increasingly severely. Heat pump technology can take advantage of the renewable energy at low temperature, which is effective in solving the energy and environmental problems in HVAC. Thus, energy saving is the core of the development of heat pump technology.Aiming at enhancing energy efficiency and improving environmental protection in energy-utilizing process, this paper proposed a new multifunctional heat pump air conditioning system which organically combined refrigerating, condensing-heat recovery, domestic hot water production and heating all together. Run in summer, the system could both recover the condensing-heat that the refrigeration cycle produced and absorb heat from the environment by heat pump. Thus, users could make it refrigerate and product domestic hot water simultaneously according to the need. The domestic hot water could be produced without restriction of the condensing-heat. The system achieved the goal of regulating both cooling capacity and domestic hot water capacity simultaneously and independently, solved the problem of mutual restriction between cooling capacity and domestic hot water capacity in established solutions, and reduced the energy wastage and the heat pollution.The paper first introduced the system's principle, and then described its nine types of operating modes and the control method and workflow of each operating mode. The paper mainly studied the system's unique function of simultaneously refrigerating and producing domestic hot water according to users' need, which distinguished from the existing techniques. In addition, it also introduced the thermodynamic calculation process under this mode, analyzed the effect of different operating parameters to the system performance and the relationship between cooling load and domestic hot water capacity when using R410A as a refrigerant. At last, the paper compared and analyzed the new system's operating characteristics when using R410A, R134a and R407C respectively.