Flow and Thermal Analysis of a Domestic Refrigerator

• Main Authors: Jia-Zheng Wu, 吳佳政
• Other Authors: Tongdar Tang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/62392910337429567416

碩士 === 華梵大學 === 機電工程研究所 === 92 === Due to the demands of energy-saving and product competition, the development of a highly efficient refrigerator becomes a very urgent job at present. The objective of this research is to combine direct experimental measurements with computational fluid dynamics modeling to study the thermal fluid phenomena in a domestic refrigerator. Experiments were carried out on a real refrigerator. Thermocouples were fixed inside the refrigerator, including freezer compartment, fresh food compartment and fruit area. The output signals from the thermocouples were connected to a computer-based data acquisition system. The computational fluid dynamics model was built to simulate the thermal and flow fields of the refrigerator. Computational fluid dynamics based on the finite volume method was employed to investigate the thermal and fluid fields, which include flow velocity and temperature distributions. The simulated model included the freezer compartment, fresh food compartment, separating plates, and flow passages. For the fluid domain, equations of conservation of mass, momentum, and energy were solved to obtain the temperature, pressure and velocity distributions. Conjugate heat transfer was utilized to comprehend the thermal fields of the solid domain. Thus temperature distributions of solid segments were also computed. The parameters, which are detrimental to the overall heat transfer efficiency, such as conduction, natural and forced convection, flow passage design, and volume flow rate, were investigated. Experimental measurements have also been used to verify the CFD model and gain a better understanding of the thermal and flow fields. The CFD model have been shown to be accurate in general. However, there are areas where the accuracy is less than satisfactory. The reasons for this may be attributed to not enough information about the wall temperature. At last, five proposals for improving the outcomes of simulations are recommended.