Search

This paper presents the investigation of Al2O3/PAG nanolubricant performance for a compact vehicle mobile air conditioning (MAC) system. The Al2O3/PAG nanolubricant in this study is prepared by using two-step preparation method and stabilized using 4-Step UV-Vis Spectral Absorbency Analysis. An enhancement in the coefficient of performance (COP), reduction in compressor work, and enhancement in the cooling capacity of MAC employing Al2O3/PAG nanolubricant are recorded up to 31%, 26% and 32%, respectively, for 0.010% volume concentration. The current MAC performance is compared with MAC employing SiO2/PAG nanolubricant from previous study. The comparison shows that the Al2O3/PAG nanolubricant has better performance in term of cooling capacity, compressor work, and COP at an average of 6%, 8%, and 33%, respectively. Therefore, the finding from this study suggests Al2O3/PAG nanolubricant with a volume concentration of 0.010% as an optimum and best performance nanolubricant for MAC systems. [ABSTRACT FROM AUTHOR]

The use of automotive air conditioning (AAC) nowadays is essential because of the hot climate and global warming. The AAC increases the overall fuel consumption in order to cool down the car cabin, hence releases more CO2 into the atmosphere. Nanotechnology can be implemented into the lubricant of the AAC compressor which can aid in reducing the power consumption. Therefore, this paper investigates the effect of SiO2/PAG nanolubricants on the AAC performance and energy saving. The SiO2/PAG nanolubricants were prepared using the two-step method. The sedimentation observation and UV-Vis spectrophotometer evaluation confirmed the stability of the nanolubricants. The tribology analysis revealed the coefficient of friction of SiO2/PAG nanolubricants better than the original PAG lubricants. The performance parameters and power consumption (energy saving) of AAC system using SiO2/PAG nanolubricants were compared with PAG lubricants. The condenser pressure and the pressure ratio of the AAC system decreased by an average of 10.8% and 5.6%, respectively. The volumetric heat absorb increased up to 3% and the coefficient of performance increased by an average of 21%. The compressor work and power consumption of the AAC system reduced by 16.5% and 4%, respectively. As a conclusion, it was recommended to use 0.05% volume concentration of SiO2/PAG nanolubricants in AAC compressor for optimum system performance and energy saving. [ABSTRACT FROM AUTHOR]

Lubrication is a requisite for any mechanical equipment that moved to avoid wear of sliding parts and enhance the equipment operation consistency. The objective of this study was to seek a new improved automotive air conditioning (AAC) compressor lubricant to enhanced AAC performances. The type of compressor is piston type, Sanden SD 7H10,that normally used by Malaysia compact car. The tribological investigation was focusing on Coefficient of friction and wear rate. The wear rate and coefficient of friction (COF) of Alumina/Polyalkylene glycol (Al2O3/PAG) nanolubricant were evaluated employing reciprocating test conditions to replicate a piston ring/cylinder liner contact following the ASTM G 181-11 Standard. Al2O3 nanoparticle was dispersed in PAG lubricant for volume concentrations between 0.006 to 0.014 vol %. Al2O3/PAG nanolubricant with 0.010 % vol. concentration showed the best reduction of frictional power loss. The enhancement of power saving due to frictional losses was up to 7.59 % compared to pure PAG lubricant. Furthermore, the wear rate of piston liner reduced by 33.39 %. Al2O3 nanoparticles in this circumstances, performed as a solid lubricant to reduce wear. These results show potential approach to enhance the AAC performance, save automotive fuel and elongated the life span for AAC compressor. [ABSTRACT FROM AUTHOR]

Thermal conductivity and viscosity of the different combination of composite nanolubricants for 0.02% volume concentrations at a temperature range of 30 to 80 °C were investigated. Al2O3, SiO2 and TiO2 nanoparticles were dispersed in the Polyalkylene Glycol (PAG 46) lubricant using the two-step method of preparation. Thermal conductivity and viscosity were measured using KD2 Pro Thermal Properties Analyzer and LVDV-III Rheometer, respectively. The result shows that the thermal conductivity and viscosity of composite nanolubricants decrease with temperature. Composite nanolubricants behaved as Newtonian in the range of the temperatures studied. The most optimum combination of composite nanolubricant is Al O3- SiO2/PAG as it yields higher enhancement in thermal conductivity but lower in viscosity. [ABSTRACT FROM AUTHOR]

Ultrasonication is the act of applying sound force to agitate particles in a sample with the frequency of more than 20 kHz. It is an external vibration induced during preparation of nanolubricant that helps the particles to overcome the van der Waals force bonding. Nanolubricant prepared is intended to be used in automotive air conditioning (AAC) system to improve its performance. In this work, stability of Al2O3/Polyalkylene glycol (PAG) and SiO2/PAG nanolubricants of 0.2 % volume concentrations with different sonication time were investigated. Five samples for each nanolubricant were prepared by two-step method process with variation of sonication time from zero to two hours' time with half an hour interval. The stability tests were done by visual sedimentation and UV-vis spectrometer. The optimum sonication time found to be one and half hours and two hours for Al2O3/PAG and SiO2/PAG nanolubricants respectively. Both nanolubricants were found stable for more than two weeks' period. [ABSTRACT FROM AUTHOR]