Study of CO2 based adsorption cooling cycle for automobile air conditioning

• Main Author: Chong, Zhi Shan.
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Mechanical engineering::Alternative, renewable energy sources
• Online Access: http://hdl.handle.net/10356/45983
• Institution: Nanyang Technological University

The purpose of this project is to study the adsorption cooling cycle using natural refrigerant CO2 (ODP= 0, GWP = 1) for automobile air conditioning system. Global warming effect and ozone depletion is potential threat to the globe due to the non-environmental friendly refrigerants used in air conditioning system and the waste heat generated from automobile combustion engine. In the study, adsorption system is introduced and due to the characteristic of no noise and no moving parts, it is very suitable for automobile air conditioning purposes. Adsorption system enables the waste heat to be reused during the desorption process and therefore reduces the impact done to the environment by unwanted waste heat exhausted. In order to simulate the cooling cycle, adsorption chillers consist of evaporator, gas coolers and four similar beds for adsorption/desorption process is modelled. MATLAB program is written to simulate the cooling process in the adsorption chillers and the result is analyzed and discussed. Linking the MATLAB to NIST (National Institute of Standards and Technology) Refprop fluid database is essential to obtain the thermodynamics fluid properties of the CO2 refrigerant. From the results of the graphs plotted, optimum switching time for adsorption/desorption phase changes in the beds can be obtained. CO2 transcritical cycle had been successfully plotted in the P-h diagram when the difficulties of handling the pressure and temperatures above CO2 critical point are solved. Using the advance technologies available today, CO2 is a promising refrigerant to be used in automobile air-conditioning system due to the environmentally friendly characteristics and it is easily available in the industry.