Research On The Characteristic And Auto-control System Of A Novel Solar Absorption Air-conditioning With An Energy Storage Unit

With the deficiency of global energy and the air-conditioning energy consume is large ratio of total family energy consume in the recent years, the study of solar air-conditioner is emphasized and concerned very much. Of the air-conditioning alternatives, the lithium-bromide/water absorption refrigeration system appears to be one of the most promising methods. This paper introduces a novel solar lithium-bromide/water absorption refrigeration cycle with an energy storage unit. It is suited to solar air-conditioning system and can resolve the disadvantages of traditional solar lithium bromide /water absorption system. The thermodynamics model of the solar mixed absorption refrigeration cycle is analyzed. The energetics equations and the Coefficient Of Performance (COP) of cycle are given. The temperature of heat resource, temperature of condensing condition and the temperature of evaporating condition are the main factors that influenced the system performance. It shows that in the proper ranges of preferences by computer simulation, the lowest COP is 0.5, the lowest available temperature difference of heat resource is 18.83℃, and the cold load for 50-60m2 room in 8 hours can be supplied by 1m3 new storage energy unit. The auto-control system model of this air-conditioning is researched. It includes signal show, energy adjustment, securities protect, equipments inspect and program runs five parts. Analyzed the response curve of heat resource disturb and user load disturb, the system employs n-order Constant Capacity Inertial Links to describe the dynamic performance of the refrigeration cycle. Under the control of PID, the paper also gives a simulation on operation process of the refrigeration cycle for optimization by changing the different parameters. Based on thermodynamics model and auto-control model, the PLC control system is given by making up of function chart, trapezium graph and control program. Use of computer replaces the air-condition machine, the experiment of PLC control system is done. The experiment results show: start from the control of particular unit; the auto-control can achieve the goal of controlling the system energy, optimization of circulation, energy storage and economy of energy. The auto-control research of solar lithium-bromide/water mixed absorption refrigeration system is very applied for solar air-conditioning's development.