汽车空调除霜风道结构优化研究

建立了3种汽车空调除霜风道模型，用以研究除霜风道内空气流动情况。利用商业软件Fluent，对速度场进行数值分析、计算流量。通过比较，得到效果较好的除霜风道结构。     

Dynamic Simulation and Performance Investigation of No-Frost Refrigerator： Part Ⅱ System Simulation and Performance Analysis

The methodology for modeling no-frost refrigerator is described based on the component models developed in Part I, and then, system simulation is applied to a BCD-235W refrigerator-freezer (RF). Experiments are carried out to study “pull-down” and steady-state performance of the RF, and to determine how the experiment and simulation temperature stack up against each other. Good match is found between simulated and measured results for the “pull-down” period. For the steady-state period, the simulation results are also found to agree well with experiment ones except for the temperature profiles of the refrigerator compartment (RC) and freezer compartment (FC). The average temperature and the energy consumption errors between measurement and simulation are less than 10%. Although the model can not reflect the non-uniform air temperature fields in the RC and FC, the variation range and periodicities of the temperature correlate well between the simulation and experiment. We conclude that such a model is valid for investigating the performance of no-frost refrigerator.      

Dynamic simulation and performance investigation of no-frost refrigerator: Part I mathematical model

A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator (RF) is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based on which the modeling simplifications are proposed. Then, the mathematical models for the evaporator, cabinet and duct-fan are presented. The whole system is divided into two subsystems—refrigerant cycling system and air cycling system. In order to simplify the model, two closed-loop systems are broken into the compressor component and the evaporator component, respectively. A general distributed parameter model is employed for evaporator with homogeneous flow to simplify the two-phase evaporating flow region. The z-transfer function model is used to describe the cabinet load. Computational fluid dynamics (CFD) method is employed to obtain the pressure drop and flow rate curve of the duct-fan model.

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