Automobile Air Conditioning System Research Articles

Experimental study on the impact of indoor unit airflow velocity on the performance of an automotive heat pump system with a suction line heat exchanger

This study aimed to investigate the effect of changing the indoor unit air flow rate on the performance of an automobile heat pump with a suction line heat exchanger. Using a four-way valve, the automotive heat pump system was developed by reversing the refrigerant direction in the automobile air conditioning system, excluding the compressor. A suction line heat exchanger was added to the test system to enhance heat transfer between the liquid and suction lines of the automotive heat pump system. Performance comparisons were first performed for R134a and R1234yf by disabling the suction line heat exchanger. Then, the suction line heat exchanger was activated for R1234yf, and the tests were repeated. Performance comparisons were made for two different compressor speeds and three different indoor unit airflow speeds. It was found that using the heat exchanger in R1234yf operations improved the heating capacity, compressor discharge temperature and coefficient of performance by approximately 1.8 %, 5.1 % and 5.9 %, respectively. The heating capacity of the heat pump system using R134a, R1234yf, and R1234yf with the suction line heat exchanger was determined to be in the range of 2.46–3.29 kW, 2.35–3.04 kW, and 2.39–3.11 kW, respectively. An increase in the airflow speed of the indoor unit from 1.4 m s−1 to 3.2 m s−1 resulted in an average decrease of approximately 12.3 % in the compressor discharge temperature. In contrast, the heating capacity and coefficient of performance increased by approximately 11.8 % and 14.4 % on average, respectively, for R1234yf operations with the heat exchanger. This study revealed that by optimizing the air flow rate in the R1234yf heat pump system with a suction line heat exchanger, improvements in the heating capacity and coefficient of performance can be achieved, thus providing better thermal comfort in the passenger compartment.

Enterovirga aerilata sp. nov. and Knoellia koreensis sp. nov., isolated from an automobile air conditioning system.

Two strictly aerobic and rod-shaped bacteria, labelled as DB1703T and DB2414ST, were obtained from an automobile air conditioning system. Strain DB1703T was Gram-stain-negative, while strain DB2414ST was Gram-stain-positive. Both strains were catalase-positive and oxidase-negative. Strains DB1703T and DB2414ST were able to grow at 18-42 °C. Strain DB1703T grew within a NaCl range of 0-3 % and a pH range of 6.0-8.0; while strain DB2414ST grew at 0-1 % and pH 6.5-8.5. The phylogenetic and 16S rRNA gene sequence analysis indicated that strains DB1703T and DB2414ST belonged to the genera Enterovirga and Knoellia, respectively. Strain DB1703T showed the closest phylogenetic similarity to Enterovirga rhinocerotis YIM 100770T (94.8 %), whereas strain DB2414ST was most closely related to Knoellia remsis ATCC BAA-1496T (97.7 %). The genome sizes of strains DB1703T and DB2414ST were 4 652 148 and 4 282 418 bp, respectively, with DNA G+C contents of 68.8 and 70.5 mol%, respectively. Chemotaxonomic data showed Q-10 as the sole ubiquinone in DB1703T and ML-8 (H4) in DB2414ST. The predominant cellular fatty acid in DB1703T was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), whereas iso-C16 : 0, C17 : 1 ω8c, and iso-C15 : 0 were dominant in DB2414ST. Overall, the polyphasic taxonomic comparisons showed that strains DB1703T and DB2414ST were distinct from their closest taxa and represent novel species within the genera Enterovirga and Knoellia, respectively. Accordingly, we propose the names Enterovirga aerilata sp. nov., with the type strain DB1703T (=KCTC 72724T=NBRC 114759T), and Knoellia koreensis sp. nov., with the type strain DB2414ST (=KCTC 49355T=NBRC 114620T).

Investigation of an automobile air-conditioner with a liquid-suction heat exchanger using R134a and R1234yf

Air-conditioning systems (ACs) are essential in hot and humid climates to ensure acceptable ambient air quality as well as thermal comfort for buildings users. It is essential to improve refrigeration system performance without increasing the effects of global warming potential (GWP) and ozone depletion potential (ODP). The main objective of this study is to evaluate the performance of an air conditioning system that operates with a liquid suction heat exchanger (LSHX) through implementing refrigerants with zero OPD and low GWP (i.e., R134a and R1234yf). Liquid suction heat exchanger (LSHX) was added to an automobile air conditioning system (AACS).When Liquid suction heat exchanger was added to the cycle, primary results indicated that an enhancement in the cycle coefficient performance (COP) by 25.2 %and 17.3% for R134a and R1234yf respectively, and decreasing in mass flow rate of the refrigerants used (m ̇_r). Also increasing in refrigeration effect (RE) by 4.2% and 2.3% for R134a and R1234yf respectively. Presence of LSHX caused increasing in heat rejected by condenser (Qcond.) according to increasing in sub-cooling degree and decreasing in compressor work (Wcomp.), increasing in condenser exergy destruction (X. des. cond.) and thermostatic expansion device (TXV) exergy destruction, but decreasing in compressor and evaporator. Summary of previous experimental and numerical studies is presented as well.

Z-Freq Hybrid: Signal Analysis Based Car Air Conditioning Compressor Monitoring Technique Using Accelerometer and Piezo-Film Sensor

The efficiency and performance of car air conditioning systems rely heavily on adequately functioning the compressor and its associated components. There are many ways to detect an unfunctioning compressor and one of them is through vibration. Disfunctioning compressors could lead to discomfort, fatigue, stress and fogging windows, especially in long-distance driving. Thus, researchers focus on detecting the nonfunctioning car air conditioning compressor early. This paper introduced a new enhanced statistical method, namely Z-freq Hybrid. Z-freq Hybrid was based on a Z-notch frequency domain filter with a combination input of two different types of sensors introduced to detect functioning compressors. Data were recorded at various compressor speeds using an accelerometer and piezo film sensor with Signal Express 2015 software. The acceleration (m/s2) and voltage (mV) data were analyzed to find the combination degree of scattering data in a Z-freq Hybrid chart. The analyzed data show that the Z-freq Hybrid coefficient increases as the compressor’s speed increases. Then, the value dropped significantly when the compressor was dysfunctional. In conclusion, a Z-freq Hybrid can be employed to detect abnormalities and irregular vibration patterns, which may indicate the impending failure of a compressor.

Energy, exergy and entropy analysis with R1234yf as an alternate refrigerant to R134a of automobile air conditioning system

A major portion of the worldwide emissions arise from mobile air-conditioning systems with hydrofluorocarbon refrigerant as working substance and which is one of major cause for the greenhouse effect. R134a refrigerant having GWP of 1400 has been extensively used in car air conditioning. To reduce greenhouse gas emissions, the current R134a refrigerant must be phase out as per Kigali Amendment. The present study deals with cooling load calculation of car model by heat balance method as per ASHRAE standard using local climate condition. Further, thermodynamic analysis of R1234yf as an alternate refrigerant to R134a has been carried out for automobile air conditioning system. The required properties of refrigerants are extracted from Engineering Equation Software. The thermodynamic analysis is carried out to study the effect of operating parameters viz. condensing temperature, evaporating tempera-ture, degree of superheating and degree of subcooling on COP, EDR, exergy efficiency and entropy generation. The previous literature reports mainly focus on separate study of either cooling load calculation or energy analysis or exergy analysis of R1234yf and R134a for au-tomobile air conditioning system, while this paper presents the comprehensive study of new low GWP R1234yf as an alternate refrigerant to R134a in automobile air conditioning system with cooling load calculation including the concept of energy, entropy and exergy analysis. The percentage difference in COP between R134a and R1234yf system varies from 2.44 % to 4.78 % while percentage difference in EDR varies from 6.79 % to 2.87 % when evaporating temperature varied from -10 °C to 10 °C. With 12 °C of superheating at compressor inlet, the COP of R134a is 3.9 whereas COP of R1234yf is 3.75, which makes 3.85 % lower than that of R134a. The R1234yf has 4.78 % lower value of exergy efficiency as compared to that of R134a at evaporating temperature of -10 °C and it is found that maximum exergy destruction takes place in compressor.

Impacts of Using AlO Nano Particle to Compressor Oil on Performance of Automobile Air Conditioning System

Impacts of Using AlO Nano Particle to Compressor Oil on Performance of Automobile Air Conditioning System

Experimental and Numerical Studies on an Automobile Air Conditioning System With the Refrigerants R134a, R1234yf, and R1234ze(E)

Abstract The Montreal Protocol of 1987 has put the chlorofluorocarbons (CFCs) into the category of ozone-depleting substances. The hydrofluorocarbons (HFCs), synthesized as alternatives to CFCs, though possess zero ozone-depleting potential, have high global warming potential (GWP). Despite this, numerous applications currently employ HFCs for refrigeration and air conditioning. The 2016 Kigali amendment to the Montreal Protocol suggested a phase out of the HFCs, and this process will go on until 2036 in developed nations and until 2047 in developing nations to accomplish a condition of 85% decrease in the use of HFCs. The refrigerant R134a used in mobile air conditioning has a global warming potential (GWP100) of 1300, which prompted researchers to look for new low GWP refrigerants. Recent research has revealed that the HydroFluoroOlefin (HFO) refrigerants R1234yf and R1234ze(E) with a GWP100 of 4 or less show promise for application in the automobile air conditioning (AAC) field. The AAC requires special attention due to frequent leakages of HFC caused by vibration-induced pipe failures. In this research, the low GWP refrigerants R1234yf and R1234ze(E) are considered to explore the AAC system performance, and comparisons are made with the currently used refrigerant R134a. The numerical simulations are performed by including and excluding liquid-to-suction heat exchanger/internal heat exchanger (IHX). The results show that the use of IHX is advantageous for both R1234yf and R1234ze(E). Even though R134a performed better, R1234yf with IHX is a better low GWP alternative in the current AAC system working with R134a without IHX, with only a slight compromise in the system performance and the performance of R1234yf is better than R1234ze(E). Finally, the numerical simulation results are validated against the experimental results for R134a and R1234yf and found that most of the results agree within 10% deviation for system without IHX and within 15% deviation for system with IHX. Thus, if the AAC systems change to R1234yf with an IHX, the directives set out in the Kigali amendment of 2016 to Montreal Protocol (namely the discontinuation of HFCs for refrigeration) will be satisfied without any significant loss in the performance.

Performance of hybrid electric vehicle air-conditioning using SiO2/POE nanolubricant

The automobile air-conditioning (AAC) system uses the most energy among all auxiliary components in hybrid electric vehicles (HEV) with an electrically-driven compressor (AAC-EDC). Incorporating nanolubricant improves AAC-EDC performance and reduces battery and AAC component size. This study aims to assess the performance of an AAC-EDC system by employing SiO2/POE nanolubricants. The performance of the AAC-EDC was examined using SiO2/POE with a volume concentration of up to 0.01 %, a refrigerant charge of 120–160 g, and a compressor speed of 1200–3840 rpm. The performance of the AAC system was measured by its heat absorption, compressor work, coefficient of performance (COP), and EDC power consumption. The SiO2/POE was stable for 30 days with a zeta potential of 102.5 mV. The SiO2/POE demonstrated superior performance over the pure POE lubricants. The compressor work and power consumption were reduced to 26.17 % and 11.97 %, respectively. The lowest expansion valve discharge temperature of 9.6 °C was achieved at 160 g refrigerant charge and compressor speed of 3840 rpm. The nanolubricant attained the highest COP of 3.36 at 1860 rpm speed and 160 g charge. The SiO2/POE nanolubricant with a volume concentration of 0.01 % is highly recommended for optimal performance in the AAC-EDC system.

Experimental investigation of the effects of compressor types on the performance of an automobile air conditioning system using R1234yf

In this study, the performance of R1234yf as an alternative to R134a has been experimentally investigated in an experimental automobile air conditioning (AAC) system with variable (VCC) and fixed (FCC) capacity compressors. The AAC system was equipped with original components and instruments for mechanical measurements. The experiments were conducted for both types of compressors and refrigerants at various compressor speeds, air temperatures entering the evaporator and condenser and air speeds passing over them. The performance parameters of the AAC system have been evaluated by performing energy and exergy analysis based on the experimental data, and the results were presented in the form of comparative graphics. The experimental results show that the VCC compressor limits the refrigerant flow rate when the capacity control system is activated due to the decrease in the evaporator and condenser air inlet temperatures and the increase in the compressor speed. It was found that the coefficients of performance (COPs) of the R1234yf AAC system with VCC and FCC were approximately 13.6% and 20.1% lower than those of the R134a system with VCC and FCC, respectively. For both refrigerants, in the AAC system with VCC, the total exergy destruction rate per unit cooling capacity was 18.2% − 47.5% lower compared to the system with FCC. The R1234yf AAC system experiences lower exergy destruction in the evaporator and condenser compared to the R134a system, while it practices higher exergy destruction in the compressor and expansion device in comparison to the R134a system

Analysis of the Coefficient of Performance (COP) on the Car’s Air Cooling System Using a Training Kit with Constant Rotation

The performance of the air condition system is strongly influenced by the compressor work, the condenser cooling temperature. So that the compressor working pressure (suction) and condenser cooling play a very important role in the performance of the air conditioning system which will have an impact on compressor work, compressor power, refrigeration impact, isentropic efficiency and coefficient of performance (COP) of the car air conditioning system. From the research, data will be obtained which include the pressure value on the refrigerant, namely P1 and P2, the temperature on the refrigerant, namely T1, T2, T3 and Tcabin, at the point of installation of the Manifold Gauge and Thermocouple. The research data is then processed and analyzed to obtain performance at constant rotation with variations in compressor working time both actual and theoretical as well as the efficiency of the ac system. From the results of the study, it was found that the compressor rotation was 2300 rpm with a constant rotation then measured the pressure and temperature of the refrigerant, then temperature data was obtained and analyzed to obtain the enthalpy value, thus obtaining the coefficient of performance (COP) of the car air conditioning system. The coefficient of performance (COP) of the resulting system is greater than the actual COP, the optimal COP occurs at P1 30 psi and P2 340 psi working pressures, the actual COP is 3.4848 and the theoretical COP is 4.1500, with an efficiency of 83.97% at 360 seconds.

Air conditioning system maintenance and repair training for youth of Karang Taruna

This work reports on social service activities at the Department of Automotive Engineering, Faculty of Engineering, Universitas Negeri Padang. This activity is targeted at out-of-school youth in Karang Taruna. The service is carried out in order to increase knowledge and skills in repairing and maintaining the Air Conditioner (AC) system in cars. Through this program, it is hoped that new experiences and knowledge can benefit the people of Karang Taruna. This program is carried out by delivering the basic theory of the car air conditioner working system. The activity is carried out using an AC system trainer. The participants were given an understanding of the methodology, the system of the refrigerants, and how to maintenance or repair the car's air conditioning system. The success rate of this activity is evidenced by the results of the post-test, in which an increment in the average score of 14.4 points.

Improving Automotive Air Conditioning System Performance Using Composite Nano-Lubricants and Fuzzy Modeling Optimization

This study aims to enhance the effectiveness of automobile air conditioning (AAC) systems through the use of composite nano-lubricants and fuzzy modeling optimization techniques. Composite nano-lubricants, which consist of varied metal oxide ingredients and content ratios, are projected to surpass single-component nano-lubricants in terms of improving the performance of AAC systems. Fuzzy modeling is used to simulate the AAC system based on experimental data using three input parameters: volume concentration of nano-lubricants (%), the refrigerant charge (g), and compressor speed (rpm). The output performance of the AAC system is measured using four parameters: cooling capacity (CC) in kW, compressor work (CW) in kJ/kg, coefficient of performance (COP), and power consumption (PC) in kW. Optimization is performed using the marine predators algorithm (MPA) to identify the best values for the input control parameters. The objective function is to minimize CW, COP, and PC while simultaneously maximizing CC and COP. Results showed that the performance of the AAC system improved from 85% to 88% compared to the experimental dataset, highlighting the potential benefits of using composite nano-lubricants and fuzzy modeling optimization for improving the energy efficiency of AAC systems. Furthermore, a comprehensive comparison with ANOVA was performed to demonstrate the superiority of the fuzzy modeling approach. The results indicate that the fuzzy model outperforms ANOVA, as evidenced by a reduced root mean square error (RMSE) for all data, from 0.412 using ANOVA to 0.0572 using fuzzy. Additionally, the coefficient of determination for training increased from 0.9207 with ANOVA to 1.0 with fuzzy, further substantiating the success of the fuzzy modeling phase.

Literature Review on Air Conditioning Heat load Analysis of a Cabin

Abstract: Air conditioning system is necessary in automobile to maintain the comfort condition. Therefore, it is important to study transient response of vehicle under real driving conditions. The Heat Balance Method (HBM) is used for estimating the heating and cooling loads which develops inside the vehicle cabin. The Load Calculation of Automobile Air Conditioning System is calculated and presented. An hourly cooling load is calculated in Tirunelveli region with respect to its latitude. Tons of refrigeration required is also found out from the cooling load calculation and a review on cooling load calculation is also presented. This study gives overall cooling load and AC power consumption which can be used by HVAC engineers to design more efficient car AC systems. Only by knowing the cooling load and source of thermal load, we can develop intelligent system to reduce AC consumption. Environmental Control System (ECS) is a generic term used in aircraft industry for maintaining the required air temperature and pressure inside passenger and crew compartment. The real challenge for an ECS is to operate and supply adequate cooling over a wide range of ground and flight conditions in a most reliable and efficient manner. The most important aspect of ECS is to know the cabin heat loads during air cooling or air heating phases. A precise calculation of aircraft heat load would be a long process requiring detailed knowledge of the aircraft structure and of the quantities involved in the mechanism of heat pick up and interchange in the cabin. This paper describes a method that may be applied in calculating the heat load for any aircraft and calculations are shown for a typical light transport aircraft under the conditions that, the cabin altitude is maintained within 0 ft to 8000 ft (2438.4m) for the aircraft altitude of 0 ft to 25000ft (7620m). The system shall be capable of maintaining temperatures within 59°F to 75°F (15°C to 30°C).

Design of air conditioner (AC) system simulator on cars to improve student competence

The purpose of this study is to design a simulator for a car air conditioning system as a learning medium, so that the learning objectives can be achieved properly and in accordance with the expected competencies. This design uses an electric motor drive to drive the AC system compressor so that it is easier to operate and does not produce air pollution and is made with a design that can be moved easily by having sturdy wheels. The electric motor is also equipped with an inverter that can adjust the rotation of the motor as in the conditions of a real car engine. This research model uses Research and Development which includes the stages: problem analysis, seeking information, designing a model, validating the design, evaluating the model, testing the model, revising the model, wider testing, finalizing the design. The results obtained are the creation of an AC simulator that has been validated by experts in terms of media and material in the very feasible category, then from the user side with 25 respondents giving a value in the very feasible category for use in learning. The increase in competency occurred by 23.90% with a comparison of the pretest value with the posttest value.

Microcontroller Integration in an Automated Power Window Circuit System for Automobile Air Conditioning

Research depicts that vehicular accident is inevitable, especially during long-distance driving journeys due to occurrence such as dehydration and discomfort owing to the inadequate or poor operating performance of car airconditioning systems which can result in loss of the driver’s attention on the road. However, the aforementioned research gap or problem needs to be addressed to ensure the efficient operation of the car air-conditioning system to avert vehicular accidents. Hence, the goal of this research is to utilize a microcontroller to automatically control the car airconditioning system to ensure enhanced operating performance. Moreover, the key merit of this research is to assist drivers by preventing them from losing attention on the road due to a phenomenon such as dehydration and discomfort, especially, during long-distance driving journeys, which can cause vehicular accidents. Besides, another imperative component of this research is to automatically control, thus closing the vehicle’s window louvre once the air conditioner is in operation or turned on to ensure efficient utilization of energy (fuel) of the vehicle and ensure that the ambience in the vehicle is pretty comfortable for the passengers on board. The automated power window system is comprehensively verified by the proteus software. Nonetheless, the results via the simulation depict that the automated power window circuit considered in this paper can effectively and automatically close the vehicle’s window louvre once the air conditioner is turned on.

Thermodynamic and carbon emission analysis with low GWP refrigerants in automobile air conditioning system

Thermodynamic and carbon emission analysis with low GWP refrigerants in automobile air conditioning system

浅谈汽车空调系统部件试验

浅谈汽车空调系统部件试验

DEVELOPMENT AND ASSESSMENT OF AIR-CONDITIONINGSYSTEM TRAINER (AirCoST)

An air-conditioning system trainer for automobile air conditioning was developed and evaluated as part of this project. This trainer's goal is to give students and technicians actual, hands-on experience in learning the functioning and workings of an automobile air conditioning system. The development of the trainer included the design and construction of a compact and portable system that simulates the working conditions of a car airconditioning system. The trainer consisted of various components, such as a compressor, condenser, evaporator, expansion valve, and refrigerant, which are interconnected with piping and electrical wiring. The trainer is equipped with sensors and gauges to measure and display the relevant parameters, such as temperature, pressure, and flow rate, of the refrigerant and air. The system is also integrated with a control panel that allows the users to adjust and monitor the system parameters. The assessment of the trainer involved testing and evaluating its effectiveness in achieving the learning outcomes. The evaluation criteria included the students' comprehension and retention of the theoretical concepts, their ability to diagnose and troubleshoot the system faults, and their proficiency in performing maintenance and repair tasks. The assessment also considered the trainer's reliability, durability, and safety aspects, as well as its ease of use and maintenance. The feedback from the users was collected and analyzed to identify the areas of improvement and to optimize the trainer's design and functionality. The development and assessment of the air-conditioning system trainer provides a valuable tool for enhancing the students' and technicians' skills and knowledge in car airconditioning. The trainer enabled them to gain practical experience in a controlled and safe environment, which prepares them for the challenges of the real-world scenarios

Design and Optimization of Automotive Air Conditioning Duct Based on CFD Algorithm

Nowadays, the air conditioner (AC), as an important guarantee for driving comfort and endurance, has attracted more and more attention. The pipe connecting the air conditioner refrigerator and the air outlet of the cockpit instrument panel is known as the air duct. Its structural characteristics and fluid flow characteristics are related to the refrigeration efficiency of the whole air conditioning system. The air supply performance of the air duct directly affects the uniformity of the temperature field and speed field in the car, thus affecting the comfort performance of the car [2]. Limited by the layout space, the design of air conditioning duct is the most difficult part of the design of automobile air conditioning system [1]. Therefore, how to optimize the air duct of automotive air-conditioning to meet the size design of the car while being more energy-efficient is an important research direction. This paper focuses on the simulation design and further optimization of the model of the air duct of automotive air conditioning through CFD algorithm. The author uses the Soildworks software for preliminary modeling, meshes the established model with Meshing, and applies the Fluent software to simulate the fluid flow characteristics in the pipe. By inputting a given flow to the inlets, the air volume of each outlet can be simulated. Based on the initial air-conditioning duct model of a vehicle model, the pipe turbulence problem and the uneven distribution of air volume at each outlet in the simulation process are improved under the condition of ensuring the existing size, and finally the rationality of the improvement is verified.

Augmentation in heat transfer by addition of double-pipe heat exchanger in automobile air-conditioning system

Due to limited fuel resources, strict emission norms, and to fight with the present threat of global warming, devising techniques to improve the fuel economy in automobiles is need of the hour. Also, the establishment of new automobile industries is increasing more competition among the industries and because of this reason manufacturer wants to deliver pioneering products with the best quality and value to their customers. In addition, air-conditioning (ac) is critical system as it is second most energy consuming unit in vehicle. Therefore, to reduce energy consumption in air-conditioning, one of the possible ways is improvement the heat transfer. This paper presents reduced fuel consumption by some modification in existing system. We implemented double-pipe heat-exchanger after condenser. The refrigerant coming out from evaporator flows at annulus side and refrigerant coming out from condenser flows at tube side. The duty cycle analysis is conducted for evaluating ac performance. The proto vehicle is tested on Pune highway. The results show enhancement in heat transfer and reduction of refrigerant pressure in condenser. The compressor power consumption is reduced to 3.42 kWhr from 8.48 kWhr at 75 kmph and COP of air-conditioning system is increased by 34%. The fuel economy is raised by 16.16%.