Modeling Analysis Of AHU With Heat Recovery

Air handling units(AHU),as an main part of the central air-conditioning system,have been widely applied considering the large air handling volume and multi-functional section combination ability.AHU can filter the air,and adjust air temperature and humidity to meet the requirements.For economic reasons,AHU with large air volume often provide heat recovery unit.Traditional Air handling units selection design relies on manual calculations,which is inefficient and inaccurate,and prototype testing highly costs.So using the computer simulation technology to build the models of each section of AHU,based on these models developed the AHU digital design and analysis system,which can design and analysis the AHU with heat recovery unit efficiently by using computer.The frame of this paper is established on the following parts:1.Fitting the parameter calculation model of water;Fitting a highly accurate formula of saturated steam of wet air.based on the parameters calculation and formula developed an accurate,high-speed,stable moist air physical parameter calculation module;Developed the heat transfer mathematical model of finned tube heat exchanger in dry conditions and wet conditions,laying the groundwork for subsequent modeling of AHU.2.Two design models and one simulation model of chilled water coils were built.The simulation model was verified by experiment.Three simulation model of cylindrical coil were built.3.Establish the simulation model of coil heat recovery based on the structural characteristics and heat transfer Regularity,the performance of coil heat recovery under different structural parameters and different working parameters were studied;Established the mathematical model of wheel heat recovery,its rationality was verified by comparison with early study results,and based on this model to analyze the variation of performance under different working conditions of wheel heat recovery.4.Based on the models developed AHU digital design and analysis system,contained the units with or without the heat recovery part.While extending the platform with information management,drawings and datas output,and developed an air psychrometric chart software which can display the air handling process.