A Comparative Performance Study of an Ejector-Expansion Refrigeration Cycle Using R134a and its Alternatives: Application of Automobile Air Conditioning

2021 ◽  
Author(s):  
Kadhim K. Idan Al-Chlaihawi ◽  
Hakim T. Kadhim ◽  
Ahmad Hashim Yousif
Keyword(s):  
Air Conditioning ◽  
Cooling Capacity ◽  
Exergy Efficiency ◽  
Refrigeration Cycle ◽  
Performance Study ◽  
Alternative Refrigerants ◽  
Suitable Alternative ◽  
Discharge Temperature ◽  
Volumetric Cooling ◽  
Automobile Air Conditioning

In this study, the performance of ejector-expansion refrigeration cycle (EERC) with R134a alternative refrigerants (R152a, R1234yf, R404A, R407C, R507A and R600a) for automobile air-conditioning application is investigated numerically. The ejector is modeled with a constant mixing-pressure assumption taking into consideration the friction effect in the ejector mixing section. The studied refrigerants are compared based on the optimum area ratio, discharge temperature, compressor input power, volumetric cooling capacity, exergy destruction, COP, exergy efficiency and COP improvement. The results show that R152a and R1234yf have the closest performance to R134a and can be considered the most suitable alternative refrigerants for R134a. The COP and exergy efficiency are improved by 2.26% and 2.27%, respectively, using R152a compared to the use of R134a, whereas they are reduced by 2.89% and 2.88% using R1234yf. The volumetric cooling capacity is reduced for both R152a and R1234yf by 6.14% and 6.8%, respectively. In addition, the effect of compressor rotational speed on the performances is reported.

scholarly journals Refrigerating fluid with a low global warming potential for automotive air conditioning systems in summer

2021 ◽  
pp. 45-45
Author(s):  
Zhaofeng Meng ◽  
Yin Liu ◽  
Dingbiao Wang ◽  
Long Gao ◽  
Junhai Yan
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Automotive Air Conditioning ◽  
Discharge Temperature ◽  
Air Conditioning Systems ◽  
Low Global Warming Potential ◽  
Lower Discharge

Refrigerants with low global warming potential (GWP) are much needed in automotive air conditioning systems. This paper compares two refrigerants, R134a (GWP=1300) and R513A (GWP=573) experimentally. The results show that the latter has lower cooling capacity, lower COP and lower discharge temperature than the former, revealing that R513A is a promising replacement of its high GWP partner.

The Development of Performance Prediction Methods for an Automotive CO2 A/C Cycle

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Akira Kaneko ◽  
Masafumi Katsuta ◽  
Takahiro Oshiro ◽  
Sangchul Bae ◽  
Shunji Komatsu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Performance Prediction ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Refrigeration Cycle ◽  
Air Conditioning System ◽  
Lubricant Oil ◽  
C Cycle ◽  
Simulation Results

In previous research, we have been focusing on the performance of the each element heat transfer and hydraulic performance of refrigeration cycle. Experimental investigations have been repeated several times, and finally, we have substantial database including the effect of lubricant oil. Moreover, the maldistribution of two-phase in an evaporator can be also predicted from the experimental database. Under these circumstances, this study is intended to effectively put the construction of an automotive CO2 air conditioning system into practical design use through the simulation using the above-mentioned database. This paper describes the refrigeration cycle performance prediction of each element (e.g., an evaporator, a gas-cooler, and so on) by a simulation using substantial database and various available correlations proposed by us and several other researchers. In the performance prediction model of heat exchangers, local heat transfer and flow characteristics are considered and, in addition, the effects of lubricant oil on heat transfer and pressure drop are duly considered. The comparison is also made between simulation results and bench test results using a real automotive air conditioning system. Finally, the developed simulation method can predict the cooling capacity successfully within ±10% for A/C system simulation. By incorporating the lubricant oil effect, the simulation results are improved to ±5% and ±15% for the cooling capacity and pressure drop for evaporator simulation, respectively.

scholarly journals Design and Analysis of a Thermoelectric Air-conditioning System

2020 ◽  
pp. 1-11
Author(s):  
A. Anthony Adeyanju ◽  
K. Manohar
Keyword(s):  
Air Conditioning ◽  
Thermoelectric Module ◽  
Cooling Capacity ◽  
Peltier Effect ◽  
Refrigeration Cycle ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Thermoelectric Air Conditioner ◽  
Air Conditioning Systems ◽  
Dc Current

Thermoelectric devices use the Peltier effect which creates a heat flux between the junctions of two different types of materials. The thermoelectric module also referred to as a heat pump transfers heat from one side to the other when a DC current is applied. This study carried out the theoretical and experimental analysis of a thermoelectric air conditioning system. A prototype thermoelectric air conditioner of 286 W cooling capacity was built and a testing enclosure made from plywood and Styrofoam was also constructed in order to validate the theoretical result with an experimentation. It was discovered that thermoelectric air conditioning took 4 minutes to reach its desired temperature of 22℃ whereas the standard air conditioning system (Refrigeration Cycle) took 20 minutes to cool to a room temperature. Economically it was also discovered that thermoelectric air conditioning system is 50% cheaper than the refrigeration cycle air conditioning systems. The thermoelectric air conditioner has cheaper maintenance and greater estimated life span of 7 years more than the refrigeration air conditioner. This is because the air conditioner that operates on the refrigeration cycle uses a rotating compressor while the thermoelectric air conditioner uses thermometric module.

scholarly journals Performance of Air Conditioning Unit under Constant Outdoor Wet-Bulb Temperature and Varied Dry-Bulb Temperature

2021 ◽  
Vol 39 (5) ◽  
pp. 1483-1490
Author(s):  
Andriyanto Setyawan ◽  
Susilawati Susilawati ◽  
Tandi Sutandi ◽  
Hafid Najmudin
Keyword(s):  
Energy Efficiency ◽  
Air Temperature ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Outdoor Air ◽  
Efficiency Ratio ◽  
Liquid Line ◽  
Discharge Temperature ◽  
Line Temperature

An experiment has been carried out for examining the performance of an air conditioning unit under constant outdoor wet-bulb temperature and varied dry-bulb temperature. During the experiment, the wet-bulb temperature of the compartment for outdoor unit was maintained at 22℃ and the dry-bulb temperature was varied from 24℃ to 36℃. The increase of outdoor air temperature results in the increase of supply air temperature, discharge temperature, suction temperature, and liquid line temperature. These cause the degradation of the air conditioner performance. An increase of power consumption by 1.4% and decrease of cooling capacity by 0.8% were observed for each 1℃ increase of outdoor air temperature. As a result, the energy efficiency ratio drops by 2% for each 1℃ increase of outdoor air temperature.

Performance Study of DC Compressor for Automotive Air Conditioning System

2012 ◽  
Vol 614-615 ◽  
pp. 674-677
Author(s):  
Nasution Henry ◽  
M.H.Z. Yamani ◽  
K. Sumeru
Keyword(s):  
Energy Efficiency ◽  
Direct Current ◽  
Electric Motor ◽  
Air Conditioning ◽  
Engine Speed ◽  
Cooling Capacity ◽  
Performance Study ◽  
Air Conditioning System ◽  
Automotive Air Conditioning ◽  
Automotive Air Conditioning System

The automotive air conditioning compressor (AAC) is belt-driven by the engine. The compressor speed is directly proportional to the engine speed. Therefore, the cooling capacity will vary as the engine speed changes. To meet the air conditioning (AC) demand, the compressor continually cycles on and off. In the research, the compressor of the AAC is driven by an electric motor which in turn is operated by electrical battery (12 volt). The use of direct current compressor (DCC) is seen as a solution of the existing system. Using the proposed system, DCC gets significant improvements in energy efficiency. Compared with AAC system, the energy conservation effect is about 77.5% to 86.35%.

Thermodynamic Analysis of Refrigeration Cycle Performance with R125/R600a Mixtures

2011 ◽  
Vol 474-476 ◽  
pp. 1643-1647
Author(s):  
Fang Wang ◽  
Xian Ping Zhang ◽  
Feng Kun Wang ◽  
Xiao Wei Fan ◽  
Zhi Wei Lian
Keyword(s):  
Thermodynamic Analysis ◽  
Cooling Capacity ◽  
Cycle Performance ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Alternative Refrigerants ◽  
Factors Affecting ◽  
Vapor Compression Refrigeration ◽  
Volumetric Cooling ◽  
Better Than

This paper deals with a thermodynamic analysis of a vapor compression refrigeration system with the new refrigerant R125/R600a blends, parameters and factors affecting the performance are investigated, and also a comparison with that of R22 is presented. Encouraging results are obtained, at a certain concentration of R125 in mixtures, the R125/R600a refrigerant blends perform better than R22 but with loss of volumetric cooling capacity in air conditioning applications. Which may provide useful information for alternative refrigerants.

Investigation of Various Mixtures of HC290/HC600 Refrigerants in Adiabatic Capillary Tube Used in Split-Type Air-Conditioner

2013 ◽  
Vol 388 ◽  
pp. 71-75 ◽  
Author(s):  
Shodiya Sulaimon ◽  
Azhar Abdul Aziz ◽  
Nasution Henry ◽  
Amer Nordin Darus
Keyword(s):  
Air Conditioning ◽  
Environmental Problem ◽  
Capillary Tube ◽  
Cooling Capacity ◽  
Montreal Protocol ◽  
Operating Pressure ◽  
Air Conditioner ◽  
Natural Substances ◽  
The Difference ◽  
Volumetric Cooling

: According to Montreal Protocol, HCFC22 (hydro chlorofluorocarbon), a commonly used refrigerant in domestic refrigeration and air-conditioner, must be phased out owing to its environmental problem. Several natural substances including ammonia, carbon dioxide, water and hydrocarbon (HC) such as propane (HC290) and butane (HC600) and their mixtures have immerged as close substitute. Literature showed that pure HC refrigerant may not be suitable enough because of the difference in operating pressure and volumetric cooling capacity when compared with HCFC22. The main objective of this study is to theoretically investigate different ratios of HC refrigerants HC290/HC600 mixtures flowing through adiabatic capillary tube using homogenous model. In this study, the percentage by volume of HC290 was varied from 30 to 40 % in a step of 5%. The pressure at the two extreme ends and temperature along the capillary tube, using HCFC22 refrigerant, which was used as benchmark, was experimentally determined in the air-conditioning (AC) system. Comparing the model results with the experimental data showed that HC refrigerants HC290/HC600 in ratio 35%/65% gave 2.95% minimum error and thus it can be used as a substitute to HCFC22 in the split-type AC system.

scholarly journals Experimental Thermodynamic Investigation on the Refrigerant Charge in a Transcritical CO2 Electric Bus Air Conditioning System

2021 ◽  
Vol 11 (12) ◽  
pp. 5614
Author(s):  
Haidan Wang ◽  
Shengbo Li ◽  
Yulong Song ◽  
Xiang Yin ◽  
Feng Cao ◽  
...  
Keyword(s):  
System Performance ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Exergy Efficiency ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
Electric Bus ◽  
Maximum Coefficient ◽  
Considerable Impact ◽  
Air Conditioning Systems

Due to its considerable impact on climate, bus air conditioning systems are being pushed to take a new and sustainable path. Electric buses relying on transcritical CO2 air conditioning units are perceived to be eco-friendly and future-proof solutions to achieving such a target. However, in order to have highly efficient air conditioning systems, the CO2 charge needs to be optimized. In this paper the energy and exergy-based analyses were performed to investigate the effect of normalized refrigerant charge on the system performance by using a test rig of a transcritical CO2 air conditioning unit for an 8 m electric bus. Results showed that the normalized refrigerant charge range of 0.248~0.336 was recommended in order to ensure the maximum coefficient of performance (COP). In addition, in sufficient charge conditions, the optimal COP, cooling capacity and exergy efficiency were 1.716, 18.97 kW and 29.79%, respectively, under the standard refrigeration condition of 35 °C/27 °C. As the ambient temperature rose from 35 °C to 40 °C, the COP, cooling capacity and exergy efficiency decreased by 16.03%, 10.90% and 12.22%, respectively. Furthermore, the exergy efficiency was found not to be sensitive to slightly insufficient charge, whereas overcharge was observed to be even beneficial to exergy efficiency under the condition of ensuring the maximum COP. In addition, insufficient refrigerant charging seriously affected the irreversible losses in the indoor and outdoor heat exchangers, whereas slight overcharge had little effect on the component exergy efficiency. Finally, the need to improve the CO2 compressor efficiency to enhance the system performance was revealed.

scholarly journals Performance assessment of alternate refrigerants for retrofitting R22 based air conditioning system

2018 ◽  
Vol 22 (2) ◽  
pp. 931-941 ◽  
Author(s):  
Mian Saeed ◽  
Shafiq Qureshi ◽  
Khurram Hashmi ◽  
Muhammad Khan ◽  
Syed Danish
Keyword(s):  
Ozone Depletion ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Air Conditioning System ◽  
Suitable Alternative ◽  
Energy And Exergy ◽  
Expansion Valve ◽  
Exergy Performance ◽  
Lower Discharge ◽  
Ozone Depletion Potential

The performance of zero ozone depletion potential refrigerants is investigated when retrofitted in R22 based air conditioning system. The options evaluated are R407C, R417A, R422D, R427A, and R438A. In order to arrive at most suitable alternative(s) to R22, energy and exergy performance of candidate refrigerants is carried out and compared against that of R22. The COP and exergy efficiencies showed that none of selected refrigerant is as efficient as R22 however their values suggests that each may be considered as potential substitute for retrofitting. Having comparable COP to others but low cooling capacity of R417A makes it less attractive. With comparatively reduced COP, lowest exergy efficiency and highest mass-flow rate, makes R422D the least desirable option. The R407C, R427A, and R438A emerged as most attractive substitutes. The lower discharge temperatures of substitutes will enhance the compressor life. Further, for substitutes there may be a possible change out of expansion valve.

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