The Experts below are selected from a list of 1977 Experts worldwide ranked by ideXlab platform
A A M Redhwan - One of the best experts on this subject based on the ideXlab platform.
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Utilization of response surface method (RSM) in optimizing Automotive Air Conditioning (AAC) performance exerting Al2O3/PAG nanolubricant
'IOP Publishing', 2020Co-Authors: A A M Redhwan, Z. M. Sharif, H. W. Azmi, N. M. N. Zawawi, S., Zainal AriffinAbstract:. This manuscript examines the performance of Automotive Air Conditioning (AAC) with the variation of the concentration of Al2O3/PAG nanolubricant, initial refrigerant charges, and compressor speed. Today, the response surface methodology (RSM) is one of the most commonly used optimization techniques for designing experimental work and for optimizing variables for a system. In this study, RSM was used to predict response parameters such as cooling capacity and compressor work. Besides, critical relationships between input and response factors will be identified using RSM. Independent variable optimization is carried out using a desirability approach to maximize cooling capacity and minimize the compressor. The results of the RSM analysis found that the optimum conditions with high desirability of 100% were at a concentration of 0.010%, cooling charge of 168 grams and compressive speed of 1160 rpm. At this optimum condition, the AAC system produces a cooling capacity of 1314 kW and a compressor work of 14.19 kJ/kg. The model predicted by RSM is accurate and has been validated in experiments with a deviation of less than 3.4%. Therefore, it can be concluded that RSM can predict optimization parameters that affect AAC performance
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Energy saving in Automotive Air Conditioning system performance using SiO_2/PAG nanolubricants
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. Mamat, G NajafiAbstract: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 CO_2 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 SiO_2/PAG nanolubricants on the AAC performance and energy saving. The SiO_2/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 SiO_2/PAG nanolubricants better than the original PAG lubricants. The performance parameters and power consumption (energy saving) of AAC system using SiO_2/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 SiO_2/PAG nanolubricants in AAC compressor for optimum system performance and energy saving.
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Application of response surface methodology in optimization of Automotive Air-Conditioning performance operating with SiO2/PAG nanolubricant
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: A A M Redhwan, M Z Sharif, W H Azmi, G Najafi, N.n.m. ZawawiAbstract:The effect of compressor speed, initial refrigerant charge and volume concentrations of SiO2/PAG nanolubricant on the performance of Automotive Air-Conditioning (AAC) system are investigated in this study. Response surface method (RSM) was used in designing the experimental work and is based on face composite design. The developed quadratic models from RSM were helpful to envisage the response parameters namely heat absorbs, compressor works, and coefficient of performance (COP) to identify the significant relations between the input factors and the responses. The results depicted that adding SiO2 nanoparticle into PAG lubricant will enhance the COP of AAC. Optimization of independent variables was performed using the desirability approach of the RSM with the goal of maximizing the heat absorb and COP, consequently, minimizing the compressor work. The results revealed that the optimal condition with a high desirability of 73.4% for the compressor speed of 900 rpm, refrigerant charge of 95 g and volume concentration of 0.07%. At this condition, the AAC system operated with 193.99, 23.28 kJ kg−1 and 8.27, respectively, for heat absorb, compressor work and COP. DoE based on RSM was capable of optimizing the significant parameters which affect AAC performance.
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Sonication time effect towards stability of Al2O3/PAG and SiO2/PAG Nanolubricants / A.A.M. Redhwan..[et al.]
Faculty of Mechanical Engineering Universiti Teknologi MARA (UiTM), 2018Co-Authors: A A M Redhwan, N.n.m. Zawawi, M Z Sharif, W H Azmi, R. MamatAbstract: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
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performance analysis of sio2 pag nanolubricant in Automotive Air Conditioning system
International Journal of Refrigeration-revue Internationale Du Froid, 2017Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. Mamat, Taib Mohd YusofAbstract:The performance of an Automotive Air Conditioning system (AAC) needs to be enhanced in order to minimize its environment impact and reduce global fuel consumption. Implementing nanofluid technology using nanolubricants inside compressors can improve its performance. Therefore, this paper presents the development of an AAC system performance test rig. The SiO2/PAG nanolubricant was prepared in a prior performance experiment and the stability of the colloidal was also attained. The experiment was conducted with initial refrigerant charge ranging from 95 to 125 gram and compressor speeds of 900 to 2100 RPM. The performance of the AAC system was evaluated by determining the heat absorb, compressor work and coefficient of performance (COP). The results found that the maximum increase and the average COP enhancement for SiO2/PAG nanolubricants are 24% and 10.5%, respectively. It can be concluded that the COP was highest at 0.05% volume concentration for all compressor speeds.
M Z Sharif - One of the best experts on this subject based on the ideXlab platform.
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Energy saving in Automotive Air Conditioning system performance using SiO_2/PAG nanolubricants
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. Mamat, G NajafiAbstract: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 CO_2 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 SiO_2/PAG nanolubricants on the AAC performance and energy saving. The SiO_2/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 SiO_2/PAG nanolubricants better than the original PAG lubricants. The performance parameters and power consumption (energy saving) of AAC system using SiO_2/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 SiO_2/PAG nanolubricants in AAC compressor for optimum system performance and energy saving.
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Composite nanolubricants in Automotive Air Conditioning system: An investigation on its performance
IOP Conference Series: Materials Science and Engineering, 2019Co-Authors: N.n.m. Zawawi, M Z Sharif, W H Azmi, A.i.m. ShaifulAbstract:AAC system is an important and necessary system in a vehicle in giving thermal comfort to the Automotive cars passenger by reducing the surrounding temperature. The experimental investigation on performance of AAC system using composite nanolubricant provides useful data for future development of Automotive cars due to its efficiency in improving the system performance. The AAC test bench was developed and utilized from Perodua Kancil. Cooling capacity, compressor work and coefficient of performance (COP) of AAC system using pure lubricant and Al2O3-SiO2/PAG composite nanolubricants had been investigated at different refrigerant charges (95 to 155g) and different speeds (900 to 2100 rpm). The result shows that the cooling capacity and COP of composite nanolubricants increased compared to pure lubricant. Meanwhile, the compressor work was reduced. Cooling capacity and COP are relatively increased by 59.91% and 7.72% respectively compared to based lubricant. The maximum reduction achievement for compressor work is by 9.35% with 155g refrigerant charge and at 2100 rpm. Therefore, Al2O3-SiO2/PAG composite nanolubricants is recommended to be used as the compressor lubrication to enhance AAC performances system.
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Comparative Study of Single and Composite Nanolubricants in Automotive Air-Conditioning (AAC) System Performance
IOP Conference Series: Materials Science and Engineering, 2019Co-Authors: A H Hamisa, N.n.m. Zawawi, M Z Sharif, W H Azmi, A.i.m. ShaifulAbstract:Various studies by leading experts have shown the effectiveness of nanolubricant in improving the performance of the Automotive Air Conditioning (AAC) system. Along with the advancement of technology, composite nanolubricant have been introduced and have been proven to have better properties than normal nanolubricant. The Al2O3-SiO2/PAG composite nanolubricant have better stability, better heat transfer, and improve tribology characteristic compare to its individual single nanoparticles nanolubricant. However, until now no experiments were conducted to test the effectiveness of composite nanolubricant in the AAC system. An experimental study is then taken by testing the Al2O3-SiO2/PAG in AAC system. The results of this experiment have been compared with results of the previous study that uses Al2O3/PAG and SiO2/PAG in AAC system. It is found that the composite nanolubricant have a high enhancement in the COP and does reduce the compressor work of the AAC system. The comparison between Al2O3-SiO2/PAG, Al2O3/PAG and SiO2/PAG nanolubricant demonstrates that Al2O3-SiO2/PAG, has better performance in term of compressor work reduction and COP enhancement at an average of 28.7 % and 31.64 %, respectively. At last, it was recommended to use the Al2O3-SiO2/PAG nanolubricant for application in AAC system.
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Application of response surface methodology in optimization of Automotive Air-Conditioning performance operating with SiO2/PAG nanolubricant
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: A A M Redhwan, M Z Sharif, W H Azmi, G Najafi, N.n.m. ZawawiAbstract:The effect of compressor speed, initial refrigerant charge and volume concentrations of SiO2/PAG nanolubricant on the performance of Automotive Air-Conditioning (AAC) system are investigated in this study. Response surface method (RSM) was used in designing the experimental work and is based on face composite design. The developed quadratic models from RSM were helpful to envisage the response parameters namely heat absorbs, compressor works, and coefficient of performance (COP) to identify the significant relations between the input factors and the responses. The results depicted that adding SiO2 nanoparticle into PAG lubricant will enhance the COP of AAC. Optimization of independent variables was performed using the desirability approach of the RSM with the goal of maximizing the heat absorb and COP, consequently, minimizing the compressor work. The results revealed that the optimal condition with a high desirability of 73.4% for the compressor speed of 900 rpm, refrigerant charge of 95 g and volume concentration of 0.07%. At this condition, the AAC system operated with 193.99, 23.28 kJ kg−1 and 8.27, respectively, for heat absorb, compressor work and COP. DoE based on RSM was capable of optimizing the significant parameters which affect AAC performance.
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Sonication time effect towards stability of Al2O3/PAG and SiO2/PAG Nanolubricants / A.A.M. Redhwan..[et al.]
Faculty of Mechanical Engineering Universiti Teknologi MARA (UiTM), 2018Co-Authors: A A M Redhwan, N.n.m. Zawawi, M Z Sharif, W H Azmi, R. MamatAbstract: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
W H Azmi - One of the best experts on this subject based on the ideXlab platform.
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Energy saving in Automotive Air Conditioning system performance using SiO_2/PAG nanolubricants
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. Mamat, G NajafiAbstract: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 CO_2 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 SiO_2/PAG nanolubricants on the AAC performance and energy saving. The SiO_2/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 SiO_2/PAG nanolubricants better than the original PAG lubricants. The performance parameters and power consumption (energy saving) of AAC system using SiO_2/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 SiO_2/PAG nanolubricants in AAC compressor for optimum system performance and energy saving.
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Composite nanolubricants in Automotive Air Conditioning system: An investigation on its performance
IOP Conference Series: Materials Science and Engineering, 2019Co-Authors: N.n.m. Zawawi, M Z Sharif, W H Azmi, A.i.m. ShaifulAbstract:AAC system is an important and necessary system in a vehicle in giving thermal comfort to the Automotive cars passenger by reducing the surrounding temperature. The experimental investigation on performance of AAC system using composite nanolubricant provides useful data for future development of Automotive cars due to its efficiency in improving the system performance. The AAC test bench was developed and utilized from Perodua Kancil. Cooling capacity, compressor work and coefficient of performance (COP) of AAC system using pure lubricant and Al2O3-SiO2/PAG composite nanolubricants had been investigated at different refrigerant charges (95 to 155g) and different speeds (900 to 2100 rpm). The result shows that the cooling capacity and COP of composite nanolubricants increased compared to pure lubricant. Meanwhile, the compressor work was reduced. Cooling capacity and COP are relatively increased by 59.91% and 7.72% respectively compared to based lubricant. The maximum reduction achievement for compressor work is by 9.35% with 155g refrigerant charge and at 2100 rpm. Therefore, Al2O3-SiO2/PAG composite nanolubricants is recommended to be used as the compressor lubrication to enhance AAC performances system.
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Comparative Study of Single and Composite Nanolubricants in Automotive Air-Conditioning (AAC) System Performance
IOP Conference Series: Materials Science and Engineering, 2019Co-Authors: A H Hamisa, N.n.m. Zawawi, M Z Sharif, W H Azmi, A.i.m. ShaifulAbstract:Various studies by leading experts have shown the effectiveness of nanolubricant in improving the performance of the Automotive Air Conditioning (AAC) system. Along with the advancement of technology, composite nanolubricant have been introduced and have been proven to have better properties than normal nanolubricant. The Al2O3-SiO2/PAG composite nanolubricant have better stability, better heat transfer, and improve tribology characteristic compare to its individual single nanoparticles nanolubricant. However, until now no experiments were conducted to test the effectiveness of composite nanolubricant in the AAC system. An experimental study is then taken by testing the Al2O3-SiO2/PAG in AAC system. The results of this experiment have been compared with results of the previous study that uses Al2O3/PAG and SiO2/PAG in AAC system. It is found that the composite nanolubricant have a high enhancement in the COP and does reduce the compressor work of the AAC system. The comparison between Al2O3-SiO2/PAG, Al2O3/PAG and SiO2/PAG nanolubricant demonstrates that Al2O3-SiO2/PAG, has better performance in term of compressor work reduction and COP enhancement at an average of 28.7 % and 31.64 %, respectively. At last, it was recommended to use the Al2O3-SiO2/PAG nanolubricant for application in AAC system.
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Application of response surface methodology in optimization of Automotive Air-Conditioning performance operating with SiO2/PAG nanolubricant
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: A A M Redhwan, M Z Sharif, W H Azmi, G Najafi, N.n.m. ZawawiAbstract:The effect of compressor speed, initial refrigerant charge and volume concentrations of SiO2/PAG nanolubricant on the performance of Automotive Air-Conditioning (AAC) system are investigated in this study. Response surface method (RSM) was used in designing the experimental work and is based on face composite design. The developed quadratic models from RSM were helpful to envisage the response parameters namely heat absorbs, compressor works, and coefficient of performance (COP) to identify the significant relations between the input factors and the responses. The results depicted that adding SiO2 nanoparticle into PAG lubricant will enhance the COP of AAC. Optimization of independent variables was performed using the desirability approach of the RSM with the goal of maximizing the heat absorb and COP, consequently, minimizing the compressor work. The results revealed that the optimal condition with a high desirability of 73.4% for the compressor speed of 900 rpm, refrigerant charge of 95 g and volume concentration of 0.07%. At this condition, the AAC system operated with 193.99, 23.28 kJ kg−1 and 8.27, respectively, for heat absorb, compressor work and COP. DoE based on RSM was capable of optimizing the significant parameters which affect AAC performance.
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Sonication time effect towards stability of Al2O3/PAG and SiO2/PAG Nanolubricants / A.A.M. Redhwan..[et al.]
Faculty of Mechanical Engineering Universiti Teknologi MARA (UiTM), 2018Co-Authors: A A M Redhwan, N.n.m. Zawawi, M Z Sharif, W H Azmi, R. MamatAbstract: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
R. Mamat - One of the best experts on this subject based on the ideXlab platform.
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Energy saving in Automotive Air Conditioning system performance using SiO_2/PAG nanolubricants
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. Mamat, G NajafiAbstract: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 CO_2 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 SiO_2/PAG nanolubricants on the AAC performance and energy saving. The SiO_2/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 SiO_2/PAG nanolubricants better than the original PAG lubricants. The performance parameters and power consumption (energy saving) of AAC system using SiO_2/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 SiO_2/PAG nanolubricants in AAC compressor for optimum system performance and energy saving.
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Energy and exergy analysis of compact Automotive Air Conditioning (AAC) system
'IOP Publishing', 2019Co-Authors: Z. M. Farid, Azmi W. H., Zawawi N. M. M., R. Mamat, A.i.m. ShaifulAbstract:Automotive Air Conditioning (AAC) is a unit that uses a high measure of energy from a car total engine power. In equatorial climate country such as Malaysia, high usage of AAC is inevitable due to hot, humid and rainy weather throughout the year. An understanding about the energy and exergy losses is essential to find the potential improvement to maximise the efficiency in an AAC system. The main objective of this study is to study the performance of energy and the exergy of a compact Automotive Air Conditioning system. This cycle uses R134a and PAG lubricant as the working fluid. The different ranges of initial refrigerant charge and compressor speed have been tested on the AAC to evaluate the effect of different major thermodynamic parameters in performance. A theoretical model is developed to work out the thermodynamic parameters such as coefficient of performance, exergy destruction ratio, component efficiency defect as well as the dimensionless exergy balance for the AAC system components. The results of this study have shown that most of the energy has been destructed in evaporator part. In order to maximize the efficiency and performance of AAC system, further optimization needs to be done in order to improve the evaporator component
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Energy saving in Automotive Air Conditioning system performance using SiO2/PAG nanolubricants
'Springer Science and Business Media LLC', 2019Co-Authors: Z. M. Sharif, Azmi W. H., R. Mamat, A. M. A. Redhwan, Najafi G.Abstract: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
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performance analysis of sio2 pag nanolubricant in Automotive Air Conditioning system
International Journal of Refrigeration-revue Internationale Du Froid, 2017Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. Mamat, Taib Mohd YusofAbstract:The performance of an Automotive Air Conditioning system (AAC) needs to be enhanced in order to minimize its environment impact and reduce global fuel consumption. Implementing nanofluid technology using nanolubricants inside compressors can improve its performance. Therefore, this paper presents the development of an AAC system performance test rig. The SiO2/PAG nanolubricant was prepared in a prior performance experiment and the stability of the colloidal was also attained. The experiment was conducted with initial refrigerant charge ranging from 95 to 125 gram and compressor speeds of 900 to 2100 RPM. The performance of the AAC system was evaluated by determining the heat absorb, compressor work and coefficient of performance (COP). The results found that the maximum increase and the average COP enhancement for SiO2/PAG nanolubricants are 24% and 10.5%, respectively. It can be concluded that the COP was highest at 0.05% volume concentration for all compressor speeds.
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investigation of thermal conductivity and viscosity of al2o3 pag nanolubricant for application in Automotive Air Conditioning system
International Journal of Refrigeration-revue Internationale Du Froid, 2016Co-Authors: M Z Sharif, A A M Redhwan, W H Azmi, R. MamatAbstract:In this paper, thermal conductivity and viscosity of the Al2O3/polyalkylene glycol (PAG) 46 nanolubricants for 0.05 to 1.0% volume concentrations at temperatures of 303.15 to 353.15 K have been investigated. Al2O3 nanoparticles were dispersed in the PAG lubricant by a two step preparation. The measurement of thermal conductivity and viscosity was performed using KD2 Pro Thermal Properties Analyzer and LVDV-III Rheometer, respectively. The results showed that the thermal conductivity of the nanolubricants increased by concentration, but decreased by temperature. Besides, the viscosity of the nanolubricants sharply increased for concentrations higher than 0.3%. However, this parameter diminished by temperature. The highest thermal conductivity and viscosity ratio were observed to be 1.04 and 7.58 times greater than the PAG lubricant for 1.0% and 0.4% concentrations, respectively. As a conclusion, it was recommended to use the Al2O3/PAG nanolubricants with concentration of less than 0.3% for application in Automotive Air Conditioning system.
Quansheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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mpc based precision cooling strategy pcs for efficient thermal management of Automotive Air Conditioning system
2019 IEEE Conference on Control Technology and Applications (CCTA), 2019Co-Authors: Hao Wang, Quansheng Zhang, Yan Meng, Mohammad Reza Amini, Ilya Kolmanovsky, Jing Sun, Mark John JenningsAbstract:In this paper, we propose an MPC-based precision cooling strategy (PCS) for energy efficient thermal management of an Automotive Air Conditioning (A/C) system. The proposed PCS is able to provide precise tracking of the time-varying cooling power trajectory, which is assumed to meet the passenger comfort requirements. In addition, by leveraging the emerging connected and automated vehicles (CAVs) technology, vehicle speed preview can be incorporated in our A/C thermal management strategy for further energy efficiency improvement. This proposed A/C thermal management strategy is developed and evaluated based on a physics-based A/C system model (ACSim) from Ford Motor Company for the vehicles with electrified powertrains. Over SC03 cycle, for tracking the same cooling power trajectory, the proposed PCS provides 4.9% energy saving at the cost of slight increase in the cabin temperature (less than 1°C), compared with Ford benchmark case. It is also demonstrated that by coordinating with future vehicle speed and shifting the A/C power load, the A/C energy consumption can be further reduced.
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mpc based precision cooling strategy pcs for efficient thermal management of Automotive Air Conditioning system
arXiv: Systems and Control, 2019Co-Authors: Hao Wang, Quansheng Zhang, Yan Meng, Mohammad Reza Amini, Ilya Kolmanovsky, Jing Sun, Mark John JenningsAbstract:In this paper, we propose an MPC-based precision cooling strategy (PCS) for energy efficient thermal management of Automotive Air Conditioning (A/C) system. The proposed PCS is able to provide precise tracking of the time-varying cooling power trajectory, which is assumed to match the passenger comfort requirements. In addition, by leveraging the emerging connected and automated vehicles (CAVs) technology, vehicle speed preview can be incorporated in our A/C thermal management strategy for further energy efficiency improvement. This proposed A/C thermal management strategy is developed and evaluated based on a physics-based A/C system model (ACSim) from Ford Motor Company for the vehicles with electrified powertrains. In a comparison with Ford benchmark case over SC03 cycle, for tracking the same cooling power trajectory, the proposed PCS provides 4.9% energy saving at the cost of a slight increase in the cabin temperature (less than 1$^oC$). It is also demonstrated that by coordinating with future vehicle speed and shifting the A/C power load, the A/C energy consumption can be further reduced.
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Energy-Optimal Control of an Automotive Air Conditioning System for Ancillary Load Reduction
IEEE Transactions on Control Systems and Technology, 2016Co-Authors: Quansheng Zhang, Stephanie Stockar, Marcello CanovaAbstract:The Air Conditioning (A/C) system is currently the largest ancillary load in passenger cars, with a significant impact on fuel economy and CO2 emissions. Considerable energy savings could be attained by simply adopting supervisory energy management algorithms that operate the A/C system to reduce power consumption of the compressor, while maintaining the cabin comfort requirements. This paper proposes a model-based approach to the design of a supervisory energy management strategy for Automotive A/C systems. Starting from an energy-based model of the A/C system that captures the complex dynamics of the refrigerant in the heat exchangers and the compressor power consumption, a constrained multiobjective optimal control problem is formulated to jointly account for fuel consumption, cabin comfort, and system durability. The tradeoff between fuel economy, performance, and durability is analyzed by performing a Pareto analysis of a family of solutions generated using dynamic programming. A forward-looking optimal compressor clutch policy is then obtained by developing an original formulation of Pontryagin’s minimum principle for hybrid dynamical systems. The simulation results demonstrate that the proposed control strategy allows for fuel economy improvement while retaining system performance and driver comfort.
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modeling and output feedback control of Automotive Air Conditioning system
International Journal of Refrigeration-revue Internationale Du Froid, 2015Co-Authors: Quansheng Zhang, Marcello CanovaAbstract:Abstract This paper presents an application of robust control theory to an Automotive Air Conditioning (A/C) system. A control-oriented model built using moving-boundary method is validated against experimental data collected on a vehicle chassis dynamometer, at constant engine speeds as well as on driving cycles. Next, an H∞ controller is synthesized by formulating an optimization problem whose solution requires appropriate weighting functions selection. Singular perturbation method is utilized to remove states associated with fast dynamics in both model and controller. Both full-order and reduced-order H∞ controllers are verified by simulation results obtained using the nonlinear A/C system model. It is demonstrated that the designed controller is capable of tracking the reference output trajectories while rejecting disturbances introduced on the boundary conditions of the heat exchangers. Furthermore, a preliminary study is performed to reveal the opportunity of designing a gain-scheduled H∞ controller for global output tracking.
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modeling Air Conditioning system with storage evaporator for vehicle energy management
Applied Thermal Engineering, 2015Co-Authors: Quansheng Zhang, Marcello CanovaAbstract:Automotive Air Conditioning (A/C) system significantly affects fuel consumption and emission. Thus, phase change material (PCM) is exploited in an innovative storage evaporator to improve the A/C system performance. Due to hybrid features introduced by mode switching when PCM changes its status between liquid and solid, the task of control-oriented modeling is particularly challenging. Upon the energy-based model built, optimal control of an advanced A/C system with a storage evaporator is formulated as to find an optimal clutch command sequence balancing fuel consumption, cabin comfort, and drivability constraints. In the scope of vehicle energy management, dynamic programming (DP) algorithm usually serves as a tool of obtaining benchmark optimal solution against which results from other optimal algorithms are compared. However, a direct application of DP algorithm to the optimization problem faces unexpected difficulty, because the discretization of state space is not feasible for an irregular multi-dimensional subspace formed by the multi-mode model. Alternatively, hybrid optimal control theory is pursued and a preliminary study is conducted to illustrate its promising application.
