Development Of APF Performance Matching Algorithm And Dynamic Characteristic Prediction Of Inverter Air Conditioner

Inverter air conditioners have the advantages of high efficiency,energy saving and comfort,and have become the leading products in the household air conditioner market.The newly issued air-conditioning energy efficiency standard GB21455-2013 "speed controllable room air conditioner energy efficiency limit value and energy efficiency grade" will use APF as the energy efficiency index of inverter air conditioner.APF is calculated from the capacity and energy efficiency under the five working conditions,including rated cooling,intermediate cooling,rated heating,intermediate heating and low temperature heating.Therefore,development of inverter air conditioners for APF needs to optimize the performance under these five test conditions.Experimental methods are mainly used to optimize APF at present.The performance matching by experiments requires whole machine experiments of the air conditioner and plenty of test conditions,which takes a lot of time.It is necessary to develop a simple and fast performance matching method.On the other hand,the energy efficiency of the inverter air conditioner is directly related to the dynamic characteristics of the air conditioner.It is necessary to accurately and quickly simulate the dynamic characteristics of the air conditioner.The existing air conditioner system simulation method can only calculate the operating characteristics of the air conditioner when the environmental conditions are constant,and cannot simulate the dynamic characteristics when the air conditioner operates in the room.The simulation method needs to be extended.Therefore,this paper studies the performance matching method of the inverter air conditioner and the calculation method of the dynamic characteristics of the air conditioner,and has obtained the following research results:(1)A performance matching method for inverter air conditioners oriented to APF is proposed.According to the analysis of the definition formula of APF in the national standard and the theoretical cycle of the refrigeration system,the APF objective function and constraints are established.The optimization algorithm under multi-constraint conditions is proposed to solve out the optimal matching capacity and the maximum APF.(2)According to the explicit formula of APF,the weights of different operating conditions in APF are deduced,and the strategy of improving APF under different working conditions is obtained.The formula for calculating the influence factors of different performance parameters in APF is deduced.The performance-matching algorithm proposed in this paper is applied to a prototype of an inverter air conditioner.It is verified by experiments and the results show that the maximum deviation of the calculation results is less than 4.8%.(3)The existing simulation methods of air-conditioning system are extended.A mathematical model of room dynamic heat conduction is established based on the existing simulation models of air-conditioning system.The dynamic characteristics of air-conditioning system in a room is calculated.The results show that the maximum deviation of the calculation results is less than 3% compared to the experiment data.The performance matching method of the inverter air conditioner proposed in this paper can accurately predict the maximum APF value and the optimal capacity and energy efficiency of the testing conditions.The deviation of each matching parameter of the experiment is within 4.8%.The calculation method of room dynamic characteristics proposed in this paper achieves the calculation of room temperature,and the error between the calculation result and the experimental result is within 3%.