Simulation and Analysis of the Characteristics of Thermal Fliuid Cycles for natural refrigerants R-600a and R-290 applying to an air-conditioning system

• Main Authors: Chun-Yi Wu, 吳俊逸
• Other Authors: Long-Jeng Chen
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/06753049924197607881

碩士 === 國立中山大學 === 機械工程學系研究所 === 88 === The characteristics of thermofluid flow cycle for natural refrigerants R-600a and R-290 applying to an air-conditioning system are studied in this project. In system performance analysis, The exergy analysis incorperated with heat transfer and fluid mechanics are also adopted to analyze the exergy transfer and destroy of each component and the whole system. The simulation parameters in this research include room temperatures, outdoor temperatures, and the types of refrigerants. If all the conditions remain constant except room temperature, the numerical results show that the coefficient of performance (COP) and the energy efficiency ratio (EER) will increase when the room temperature increases, or the outdoor temperature decreases. If all simulation conditions are the same, COP and EER with R-600a is better than those with R-290. By using exergy analysis, the numerical results show that the flow exergies through compressor and expansion valve will decrease due to the friction of the fluid flow. However, the flow exergies through condenser and evaporator will decrease due to finite-temperature heat transfer and energy carried away by exterior air. The destruction of the flow exergy due to the irreversibility of the frictional fluid flow is relative small to heat transfer. By using the exergy analysis, we can clearly understand the exergy change within each component of an air-conditioning system. This treatment is very useful in the design of air-conditioning systems and its optimum analysis.