Steady-state Performance Simulation Of Room Air-conditioning System Based On Modelica

Air conditioning and refrigeration systems are composed of many components suchas compressor,condenser,evaporator,capilliary and so on.To simulate air conditioning andrefrigeration systems is helpful for us to analyse the relations between the system’s keyproperties and its main parameters,the results can give us clue on how to determine themain parameters and how to choose different components to form a better system whenwe design the air-conditioner.Besides it is the prerequisite for the optimization of airconditioning and refrigeration systems.For these reasons,3aspects of this issue are studiedin this thesis.Firstly,air-conditioner component models are built and they are suitable forsystematic simulation. For example,the lumped parameter method is used to modelcompressor,the distributed parameter method is used to model the condenser andevaporator,the distinguished phase lumped parameter method is used to modelcapilliary.the form-lookup method are coupled with the simplified thermodynamic formulamethod to model the refrigerant. These treatments can meet the demand on accuration ofthe simulation,at the same time it largely reduces the simulation time and enhance thestability of the simulation.Secondly, a steady-state performance modeling library of air-conditioning system isbuilt on Modelica.Compressor,condenser,evaporator and capillary are included in thislibrary.Then a systematic model is built based on this library according to theair-conditioner’s topology structure.The air-condition model library built is open,whichmakes it fit for knowledge accumulation.At the same time,it makes a good preparation forthe following systematic steady-state performance simulation of the air-conditioningsystem.Lastly, The basic analytical and solving theory of the simulation plateform ofMWorks are studied in depth.Based on this, the systematic simulation is carried out toanalyse the heat exchangers’ characteristic,the system’s frequency characteristic and theworking condition’s influence on the overall system.Besides multi-objective optimizationcan be carried out on the platform of Mworks if the library models are proved to coincidewith the experimental data accurately.