Automobile Air Conditioning System Research Articles

Investigation on the improvement of car air conditioning system performance using an ejector

The purpose of this research is to know the improvement of car air conditioner system performance using an ejector. The study was conducted on a car engine with power 100 PS (74 kW) @ 5000 rpm. The test procedure is carried out under two conditions: the normal refrigeration cycle mode and the refrigeration cycle mode with the ejector. The working fluid used in the refrigeration cycle is R-134a. Performance data was measured on engine revolutions ranging from 1500 - 3000 rpm. Finally, the results showed that ejector usage on AC system generates an increase in the refrigeration effect and coefficient of performance (COP) of 25% and 22%, respectively. This has implications to better cooling capacity and compressor work that is lighter.

Deinococcus multiflagellatus sp. nov., isolated from a car air-conditioning system.

A gamma radiation-resistant and pink-to-red pigmented bacterial strain, designated ID1504T, was isolated from a car air-conditioning system sampled in Korea. The cells were observed to be Gram-stain negative, aerobic, motile with peritrichous flagella and short rod-shaped. Phylogenetically, the strain groups with the members of the genus Deinococcus and exhibits high 16S rRNA gene sequence similarities with Deinococcus arenae SA1T (94.0%), Deinococcus actinosclerus BM2T (93.9%) and Deinococcus soli N5T (93.5%). The predominant fatty acids were identified as C17:0, C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and iso-C17:0. The major respiratory quinone was identified as MK-8. The polar lipids were found to be comprised of unidentified phospholipids, unidentified glycolipids, an unidentified aminophospholipid and an unidentified lipid. The DNA G+C content of the strain was determined to be 68.3mol%. On the basis of the phenotypic, genotypic and chemotaxonomic characteristics, strain ID1504T should be classified in a novel species in the genus Deinococcus, for which the name Deinococcus multiflagellatus sp. nov. (=KACC 19287T=NBRC 112888T) is proposed.

Spirosoma carri sp. nov., isolated from an automobile air conditioning system.

A Gram-stain-negative and yellow-pigmented bacterial strain, designated TX0406T, was isolated from an automobile evaporator core collected in Korea. The cells were non-motile, aerobic and rod-shaped. The strain grew at 15-37 °C (optimum, 25 °C), at pH 6.0-7.0 (optimum, 6.5) and in the presence of 0-1.5 % (w/v) NaCl. Phylogenetically, the strain was related to members of the genus Spirosoma(93.7-90.7 % 16S rRNA sequence similarities) and showed the highest sequence similarity of 93.7 % to Spirosomapulveris JSH5-14T. The major fatty acids of the strain were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 1ω5c and C16 : 0. The predominant menaquinone was MK-7. The polar lipid profile revealed the presence of phosphatidylethanolamine, an unidentified aminolipid, unidentified aminophospholipids and unidentified lipids. The DNA G+C content of the strain was 58.7 mol%. Based on phenotypic, genotypic and chemotaxonomic data, strain TX0406T represents a novel species in the genus Spirosoma, for which the name Spirosoma carri sp. nov. (=KACC 19013T=NBRC 112494T) is proposed.

Sphingomonas carri sp. nov., isolated from a car air-conditioning system.

A Gram-stain-negative, yellow-pigmented bacterial strain, designated PR0302T, was isolated from a car evaporator core collected in Korea. The cells were strictly aerobic, non-spore-forming and rod-shaped. The strain grew at 15-37 °C (optimum, 25 °C), at pH 6.0-8.0 (optimum, 7.0) and in the presence of 0-1 % (w/v) NaCl. Phylogenetically, the strain was closely related to members of the genus Sphingomonas(97.04-91.22 % 16S rRNA gene sequence similarities) and showed the highest sequence similarity of 97.04 % to Sphingomonas kyeonggiensis THG-DT81T. It contained C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C14 : 0 2-OH as the predominant fatty acids and Q-10 as the major ubiquinone. The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid. The major polyamine was sym-homospermidine. The serine palmitoyl transferase gene (spt) was detected and sphingolipid synthesis was confirmed. The mean DNA G+C content of the strain was 67.8±0.5 mol%. DNA-DNA relatedness between strain PR0302T and closely related type strains of Sphingomonas species was less than 30 %. The low levels of DNA-DNA relatedness identified strain PR0302T as a member of a novel species in the genus Sphingomonas. Based on phenotypic, genotypic and chemotaxonomic data, strain PR0302T represents a novel species in the genus Sphingomonas, for which the name Sphingomonas carri sp. nov. is proposed. The type strain is PR0302T (=KACC 18487T=NBRC 111532T).

Control of flash gas bypass MAC system with emphasis on start-ups and transients

Most of the previous research on flash gas bypass (FGB) focused on performance improvement in steady state and demonstrated that compared to direct expansion mode (DX), FGB mode have better performance. However, the control strategy of flash gas bypass system and dynamic behavior during start-ups and transients were not yet clearly defined and investigated. In this paper, a novel control strategy has been proposed for an automobile air conditioning system operating in flash gas bypass mode with R134a as the refrigerant. The proposed control strategy utilized an electronic expansion valve (EV) for the control of subcooling from condenser outlet and a bypass valve (BV) for superheat from compressor inlet. Both start-up and transient system behaviors were studied. The experimental results showed that the proposed cycle control strategy was found to be able to provide reliable control to the system. In addition, proper sizing of bypass valve and flash gas bypass tank have also been studied.

Spirosoma metallum sp. nov., isolated from an automobile air conditioning system

A Gram-stain-negative and yellow-pigmented bacterial strain, designated TX0653T, was isolated from an automobile evaporator core collected in Korea. The cells were aerobic and rod-shaped. The strain grew at 10-28°C (optimum, 25°C), at pH 6.0-7.5 (optimum, 6.5), and in the presence of 0-1% (w/v) NaCl (optimum, 0%). Phylogenetically, the strain was related to members of the genus Spirosoma (95.1-90.8% 16S rRNA sequence similarity) and distantly related to Spirosoma pulveris JSH5-14T (95.1%), Spirosoma fluviale MSd3T (95.0%), Spirosoma endophyticum DSM 26130T (94.8%), and Spirosoma linguale DSM 74T (94.6%). The major fatty acids of the strain were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), C16:1 ω5c, iso-C15:0, iso-C17:0 3-OH, and C16:0. MK-7 was identified as the predominant menaquinone. The polar lipids profile indicated the presence of one phosphatidylethanolamine, one unidentified aminolipid, one unidentified aminophospholipid, two unidentified phospholipids, and three unidentified lipids. On the basis of the phenotypic, genotypic, and chemotaxonomic characteristics, strain TX0653T represents a novel species in the genus Spirosoma, for which the name Spirosoma metallum sp. nov. (=KACC 19278T=NBRC 112495T) is proposed.

Comparative Evaluation of an Automobile Air - Conditioning System Using R134a and Its Alternative Refrigerants

Abstract This research involves the theoretical aspects of R134a automobile air conditioning system. The main aim of the research is to evaluate the different alternative refrigerants as a drop in substitute of R134a theoretically. For this purpose, thermodynamic properties of different alternative refrigerants i.e. R290, R600a, R407C, R410A, R404A, R152a and R1234yf are compared to R134a. Thermodynamic evaluation of standard rating cycle of vapour compression refrigeration system is carried out. Engineering equation solver and refprop soft wares have been used for the thermodynamic analysis purpose. From thermodynamic analysis, it is derived that R1234yf is best suitable alternative refrigerants as a drop in substitute of R134a. R1234yf has lower coefficient of performance as compared to R134a; however it is best suitable alternative refrigerants as a drop in substitute because it has very low global warming potential and can be substituted in the existing automobile air conditioning system with minimum modification.

Comparative study of thermo-physical properties of SiO2 and Al2O3 nanoparticles dispersed in PAG lubricant

Currently, the possibility to enhance fuel efficiency with cutting edge advancements is thoroughly investigated by researchers. One of the best ways to increase the fuel efficiency is by improving the performance of the automobile air conditioning system. As a result, nanoparticles are dispersed in the lubricants of automobile air conditioning compressor for heat transfer and tribology enhancement. In this paper, viscosity and thermal conductivity of the SiO2 nanoparticles dispersed in Polyalkylene glycol (PAG) lubricants for 0.2–1.5% volume concentrations and 303–353K working temperatures was investigated and compared with Al2O3 nanolubricant. The viscosity and thermal conductivity of the nanolubricants increased with volume concentration but decreased with temperature. The paper proposed correlations for viscosity and thermal conductivity of SiO2 nanolubricants at various concentrations and temperatures. The allowable volume concentration of SiO2 and Al2O3 nanolubricants for application in automobile air conditioning compressors are up to 1.0% and 0.3%, respectively. The thermal conductivity of SiO2 nanolubricants at 1.0% concentration is higher than Al2O3 nanolubricants at 0.3% allowable concentration. As a conclusion, it is advisable to use the SiO2 nanolubricants with volume concentration of less than 1.0% for applications in automotive air conditioning system.

Experimental research and optimization on the environmental friendly R1234yf refrigerant in automobile air conditioning system

Currently, the refrigerant used in the automotive air conditioning system is R134a which has a high global warming potential (GWP) value, so people are eager to find a good replacement for it. According to recent studies, R1234yf is considered as one of the top candidates to replace R134a. In this article, the performances of R1234yf “drop-in” system and the optimization to the R1234yf system are experimentally studied and investigated. The expansion valve used for the R1234yf system is optimized by changing the charged fluid and adjusting the spring force. The results indicate that it can improve the performance of R1234yf system significantly through adjusting the thermostatic expansion valve. For the thermostatic expansion valves (TEVs) charged with R134a in thermal bulb, the system performance is optimal. Compared to the original expansion valve, for the R1234yf system applying the adjusted expansion valves, under different working conditions the cooling capacity increases by 11.3% averagely and the coefficient of performance (COP) increases by 8% averagely.

Second law analysis of an automotive air conditioning system using HFO-1234yf, an environmentally friendly refrigerant

In this paper, a comparative study of the second law of thermodynamics is presented to determine the possibility of using HFO-1234yf, an environmentally friendly refrigerant, as a drop-in replacement of HFC-134a in automotive air conditioning system. For the thermodynamic analysis, a computer program is written to simulate the operating conditions of automobile air conditioning system. The thermodynamic properties of the refrigerants are extracted from the REFPROP 8.0 software. For calculating the coefficient of performance (COP), exergy destruction, exergy efficiency and entropy generation, computational models are used to evaluate the effects of different parameters on their changes. It is found that using HFO-1234yf as the air conditioning refrigerant leads to higher exergy efficiency compared to HFC-134a. Also, maximum entropy generation and exergy destruction occur in the compressor. The exergy destruction and entropy generation of the cycle components are less in the case of using HFO-1234yf refrigerant instead of HFC-134a.

Mucilaginibacter carri sp. nov., isolated from a car air conditioning system.

A Gram-stain-negative, pink bacterial strain, designated PR0008KT, was isolated from an automobile evaporator core in Korea. The cells were obligately aerobic and rod-shaped. The strain grew at 10-40 °C (optimum, 20 °C), at pH 5-8 (optimum, 7), and in the presence of 0-1.5% (w/v) NaCl. Phylogenetically, the strain was closely related to members of the genus Mucilaginibacter (93.4-97.0% 16S rRNA sequence similarities) and showed a high sequence similarity with Mucilaginibacter litoreus BR-18T, Mucilaginibacter lutimaris BR-3T and Mucilaginibacter soli R9-65T (97.0%, 96.9% and 96.9% 16S rRNA sequence similarity, respectively). It contained summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16 : 0, iso-C17:0 3-OH and C16:0 as the predominant fatty acids and MK-7 as the major menaquinone. The polar lipids were phosphatidylethanolamine, one unknown aminophospholipid, two unknown aminolipids and two unknown polar lipids. The DNA G+C content of this strain was 47.4 mol%. Based on the phenotypic, genotypic and chemotaxonomic data, strain PR0008KT represents a novel species in the genus Mucilaginibacter, for which the name Mucilaginibacter carri sp. nov. (=KACC 17938T=NBRC 111539T) is proposed.

Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC) system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP). Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X . In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X , the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T 5 (35oC), or at T 5 = 30oC for constant X (4.96).

Spirosoma aerolatum sp. nov., isolated from a motor car air conditioning system.

A Gram-stain-negative, yellow-pigmented bacterial strain, designated PR1012KT, was isolated from a motor car evaporator core collected in Korea. Cells of the strain were facultatively anaerobic, non-spore-forming and rod-shaped. The strain grew at 10-40 °C (optimum, 25 °C), at pH 6.5-8.0 (optimum, pH 7.0-8.0) and in the presence of 0-1% (w/v) NaCl. Phylogenetically, the strain was closely related to members of the genus Spirosoma (97.50-90.74% 16S rRNA gene sequence similarities) and showed highest sequence similarity to Spirosoma panaciterrae DSM 21099T (97.50%). Its predominant fatty acids included summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:1ω5c, iso-C15:0 and summed feature 4 (iso-C17:1 I and/or anteiso B) and it had MK-7 as the major menaquinone. The polar lipids present included phosphatidylethanolamine, one unknown aminophospholipid, two unknown aminolipids and five unknown polar lipids. The DNA G+C content of this strain was 54 mol%. Based on phenotypic, genotypic and chemotaxonomic data, strain PR1012KT represents a novel species in the genus Spirosoma, for which the name Spirosoma aerolatum sp. nov. is proposed. The type strain is PR1012KT ( = KACC 17939T = NBRC 110794T).

Deinococcus metallilatus sp. nov. and Deinococcus carri sp. nov., isolated from a car air-conditioning system.

Two bacterial strains, designated MA1002(T) and MA1003(T), were isolated from the air-conditioning system of a car. Cells of both strains were Gram-reaction-positive, non-motile, non-spore-forming coccoids, catalase- and oxidase-positive and UV-radiation resistant. The major fatty acids of strain MA1002(T) were iso-C17 : 0 and iso-C15 : 0 and those of strain MA1003(T) were iso-C16 : 0 and iso-C16 : 1 H. The polar lipid profile of MA1002(T) contained phosphatidylethanolamine, two unidentified phosphoglycolipids, an unidentified phospholipid, an unidentified aminophospholipid, an unidentified aminolipid and an unidentified lipid. MA1003(T) had three unidentified phosphoglycolipids, six unidentified phospholipids, two unidentified glycolipids and two unidentified polar lipids as the polar lipids. The G+C contents of the genomic DNA of MA1002(T) and MA1003(T) were 70.5 and 76.0 mol%, respectively. MK-8 was the predominant respiratory quinone for both strains. 16S rRNA gene sequence analysis showed that strain MA1002(T) was phylogenetically related to Deinococcus apachensis DSM 19763(T), D. geothermalis DSM 11300(T), D. aerius TR0125(T) and D. aetherius ST0316(T) (92.9, 92.6, 92.0 and 91.9% sequence similarity, respectively), and MA1003(T) showed the highest sequence similarity to Deinococcus hopiensis KR-140(T) (92.9%) and D. xinjiangensis X-82(T) (91.4%). The results of genotypic and phenotypic characterizations showed that both strains could be distinguished from phylogenetically related species, and that the strains represented novel species within the genus Deinococcus, for which we propose the names Deinococcus metallilatus sp. nov. (type strain MA1002(T) = KACC 17964(T) = NBRC 110141(T)) and Deinococcus carri sp. nov. (type strain is MA1003(T) = KACC 17965(T) = NBRC 110142(T)).

Synthetic utility of 2,3,3,3-tetrafluoroprop-1-ene (HFO-1234yf)

Abstract 2,3,3,3-Tetrafluoroprop-1-ene, known as the environmentally benign fluorinated olefin recently employed for the car air-conditioning system, was proved to follow the addition–elimination sequence at its C2 position by the reaction of a variety of alkoxides, forming CF3-containing vinyl ethers in excellent yields.

PERFORMANS VERİ ANALİZLERİNE BAĞLI OLARAK DENEYSEL BİR OTOMOBİL KLİMA SİSTEMİNİN KONTROLÜ

Nowadays, using of advanced control methods in order to realize the safe and economical applications at many fields like automotive, biomedical, industrial production, remote machine control, storage and following, building and factory automation has became great importance. On these type industrial applications, PID controller is one of the commonly used controller types. In this study an experimental automobile air conditioning system has been equipped with electrical measuring devices and has been constructed in laboratory. Immediate data comes from sensors throughout the realized data collection and control system is processed in computer with modbus protocol and performance analyze of the system can be made. The created interface program can intervene in measurements like engine speed, internal and external unit air temperature and speeds. By this means, it is aimed to being operate an automobile air conditioning system in the most ideal environment.

Environmental Sustainability of Automobile AIR-Conditioning System with Refrigerant R1234YF

Air- conditioning refrigerant R134a has value of global warming potential (GWP) 1300, which is much higher than MAC Directive (GWP below 150) passed in July 2006. This prompted a search for alternative eco-friendly refrigerant with GWP value less than 150. R1234yf is a new refrigerant which has lower GWP value of 4. Effect of blower speed in car air-conditioning has been compared and flammability issue of R1234yf has been addressed. Cooling time and relative humidity of car air-conditioning system using refrigerant R134a and R1234yf has also been discussed. The paper discusses various aspects for the replacement and provides a long term substitute of presently used refrigerant R134a in automobile air-conditioning for sustainable environment.

The Design of Based on AT89C52 Automotive Air Conditioning Control System

This topic through to the automobile air conditioning working principle and the structure analysis of air conditioning assembly, with AT89C52 as the core of single-chip microcomputer control system is designed, and the controller hardware and part of the circuit design; To realize fuzzy control algorithm of the control system is established. Expounds how to realize the automation of automobile air conditioning system of fuzzy control; Temperature detection with high precision integrated temperature sensor MF51 implementation; Programming process, adopts the modular design method of each module respectively for programming, debugging, then connect them in accordance with the requirements of control, the debugging, analysis.

자동차 에어컨 쾌적제어 알고리즘 개발을 위한 운전자 온열감성 평가 : 제 1 보-운전자의 에어컨 조작 선호도

In this study, we investigated and evaluated the air conditioning operation of the driver according to the temperature difference between the inside and outside of a car parked outside during the summer. We suggest including a comfort mode to the car air conditioning system to improve the thermal comfort of the driver, in which the comfort can be maintained for a longer time. For the a result of our experiment, in the cases with temperature of above <TEX>$45^{\circ}C$</TEX> inside of the car, the subjects preferred strong air blow with the face and the arms in the direction of the blow. In the cases with temperature of below <TEX>$40^{\circ}C$</TEX> inside of the car, the subjects preferred lower volume of air blow. In the temperature below <TEX>$28.1^{\circ}C$</TEX> inside of the car, the mean temperature on the skin of the driver reached the comfort zone.

Facility Set For New Coolant

Honeywell is placing a $300 million bet that automakers will adopt a new fluorinated refrigerant for car air-conditioning systems. The New Jersey-based technology conglomerate says it and its raw m...