Performance testing of vapor compression system of aircon system

• Main Author: Heng, Eugene Yi Jian.
• Other Authors: Cai Wenjian
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/40597
• Institution: Nanyang Technological University

This project describes the construction and performance testing of the vapor compression cycle (VCC). In addition to that, it also analyzes the various data collected and aims study the COP based on a fixed EEV opening degree and varying the compressor, condenser and evaporator fan frequency. This project uses R134a as the working refrigerant and the concept of multievaporators and EEVs integrated with the system. Firstly, the various components like the condensers, EEVs, evaporators and etc were put together to construct the system. Following that, various tests were carried out and analyzed before determining the range of COP. Studies has found out that the on-off cycling of the system causes the coefficient of performance (COP) to be below 75% of the steady-state values. The transient losses during cycling are mainly attributed to two different phenomena: thermodynamic losses (heat exchangers mass) and start/stop losses (refrigerant migration). Many studies have been done on refrigeration systems with single evaporator or single EEV but this is not the case for multi evaporators and EEVs [1]. The multievaporator air-conditioner (MEAC) consists of one compressor, one condenser, several evaporators and the same number of expansion valves [2]. In this project, the MEAC uses one compressor to drive several evaporators simultaneously therefore, its dynamics are more complicated than the single-evaporator machine [2]. It was found that the COP ranged from 2.66 to 3.85 and the performance was affected especially when the compressor frequency was changed.