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.

The Development of Performance Prediction Methods for an Automotive CO2 Air Conditioning Cycle

2010 ◽  
Author(s):  
Masafumi Katsuta ◽  
Takahiro Oshiro ◽  
Akira Kaneko ◽  
Sangchul Bae ◽  
Shunji Komatsu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Data Base ◽  
Performance Prediction ◽  
Air Conditioning ◽  
Refrigeration Cycle ◽  
Air Conditioning System ◽  
Lubricant Oil ◽  
Simulation Results ◽  
Cooling Ability

In previous researches, 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 data base including the effect of lubricant oil. Moreover, the mal-distribution of two-phase in an evaporator can be also predicted from the experimental data base. 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 data base. 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 data base 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 ability successfully within ±5%. By incorporating the lubricant oil effect, the simulation results are improved to ±5% and ±15% for the cooling ability and pressure drop 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.

Thermal-Fluid Characteristics of an Automotive Radiator Used as the External Heat Exchanger in an Auto Air Conditioning System

2005 ◽  
Author(s):  
Amir Jokar ◽  
Mohammad H. Hosni ◽  
Steven J. Eckels
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Thin Plate ◽  
Air Conditioning ◽  
External Heat ◽  
Air Conditioning System ◽  
Louvered Fins ◽  
External Heat Exchanger ◽  
Fluid Characteristics

The thermal-fluid characteristics of an automotive radiator, used as the external heat exchanger in an auto air conditioning system, are experimentally analyzed and discussed in this article. The radiator in this study is a compact heat exchanger with parallel rectangular minichannels and louvered thin-plate fins. A 50% glycol-water mixture flows through the minichannels with staggered surface enhancements on the walls. On the other side, air flows through the radiator openings with the louvered thin-plate fins sandwiched between the minichannels. Single-phase heat transfer and pressure drop correlations for glycol-water flow within the minichannels and for air flow through the louvered fins are obtained and presented. The Wilson plot technique is applied to find the heat transfer coefficients on both the glycol-water and air sides. The frictional pressure drop for the glycol-water flow within the minichannels is also obtained using the Fanning equation. The uncertainty estimates for both measured and calculated parameters are then presented, and finally the results are plotted, discussed and compared with the relevant previous studies. These results show that the heat transfer rate is increased in the glycol-water side due to the surface enhancements in comparison with smooth rectangular channels. The heat transfer is enhanced on the air side as well, as compared with the flat smooth surfaces, due to the use of louvered fins.

RESEARCH OF HEAT TRANSFER AND PRESSURE DROP CHARACTERISTIC OF CONCAVO-CONVEX PLATE

2013 ◽  
Vol 21 (02) ◽  
pp. 1350012 ◽  
Author(s):  
AKIRA KANEKO ◽  
MASAFUMI KATSUTA ◽  
YUKI HAMANO
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Performance Improvement ◽  
System Performance ◽  
Air Conditioning ◽  
Parallel Plates ◽  
Pump System ◽  
Air Conditioning System ◽  
Heat Pump System

For an automobile air-conditioning system, performance improvement of the heat exchanger is needed to fit in the change of refrigerant and heat pump system. In this study, the heat transfer and pressure drop characteristic of air flow between parallel plates with concavity and convexity is grasped, and the possibility of using a fin-less heat exchanger is considered analytically. And it has been shown that a fin-less heat exchanger has the possibility of increasing performance compared to a conventional heat exchanger, which uses a corrugated louver fin.

Heat Exchanger Working Condition under Low Temperature and Simulation

2014 ◽  
Vol 1070-1072 ◽  
pp. 1690-1695
Author(s):  
Zhi Yuan Wang ◽  
Liu Wang
Keyword(s):  
Heat Exchanger ◽  
Low Temperature ◽  
Air Conditioning ◽  
Working Condition ◽  
Electrical Power ◽  
Cooling Capacity ◽  
Finned Tube ◽  
Air Conditioning System ◽  
System Parameters ◽  
Simulation Results

The frost is easy produced by the surface of evaporator, when finned tube evaporator works, especially in the low temperature and high humidity conditions. COP, electrical power, cooling capacity and frost quantity have significant differences at the conditions of different temperature and humidity. When air conditioning system is used in different areas, system parameters change greatly, so it is important that the experimental research on the heat exchanger in low temperature conditions. The temperature field of the evaporator is calculated and simulated by software, and the simulation results are analyzed and explained.

Rechargeable Personal Air Conditioning Device

2016 ◽  
Author(s):  
Yilin Du ◽  
Jan Muehlbauer ◽  
Jiazhen Ling ◽  
Vikrant Aute ◽  
Yunho Hwang ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Cooling Capacity ◽  
Comfort Level ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
System A ◽  
Single Person ◽  
Vapor Compression Cycle ◽  
Compression Cycle

A rechargeable personal air-conditioning (RPAC) device was developed to provide an improved thermal comfort level for individuals in inadequately cooled environments. This device is a battery powered air-conditioning system with the phase change material (PCM) for heat storage. The condenser heat is stored in the PCM during the cooling operation and is discharged while the battery is charged by using the vapor compression cycle as a thermosiphon loop. The conditioned air is discharged towards a single person through adjustable nozzle. The main focus of the current research was on the development of the cooling system. A 100 W cooling capacity prototype was designed, built, and tested. The cooling capacity of the vapor compression cycle measured was 165.6 W. The PCM was recharged in nearly 8 hours under thermosiphon mode. When this device is used in the controlled built environment, the thermostat setting can be increased so that building air conditioning energy can be saved by about 5–10%.

DESIGN OF THE CABIN CONDITIONING SYSTEM OF AGRICULTURAL MACHINE

2020 ◽  
Author(s):  
Y.I. Babenkov ◽  
◽  
A.I. Ozersky ◽  
V.V. Romanov ◽  
G.A Galka ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Good Health ◽  
Cooling Capacity ◽  
Air Conditioning System ◽  
Agricultural Machine ◽  
Hard Currency

The article is devoted to the issue of designing an air conditioning system (SСA) of the cabin of an agricultural machine to create comfortable conditions and ensure good health of the driver. The methodology for determining heat inflows and moisture inflows into the cabin is shown. The required cooling capacity of hard currency is calculated using the i-d diagram.

scholarly journals Design Evaluation for a Finned-Tube CO2 Gas Cooler in Residential Applications

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2428 ◽  
Author(s):  
Charalampos Alexopoulos ◽  
Osama Aljolani ◽  
Florian Heberle ◽  
Tryfon C. Roumpedakis ◽  
Dieter Brüggemann ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Air Conditioning ◽  
Design Procedure ◽  
Finned Tube ◽  
Co2 Gas ◽  
Ambient Temperatures ◽  
Overall Heat Transfer Coefficient

Towards the introduction of environmentally friendlier refrigerants, CO2 cycles have gained significant attention in cooling and air conditioning systems in recent years. In this context, a design procedure for an air finned-tube CO2 gas cooler is developed. The analysis aims to evaluate the gas cooler design incorporated into a CO2 air conditioning system for residential applications. Therefore, a simulation model of the gas cooler is developed and validated experimentally by comparing its overall heat transfer coefficient. Based on the model, the evaluation of different numbers of rows, lengths, and diameters of tubes, as well as different ambient temperatures, are conducted, identifying the most suitable design in terms of pressure losses and required heat exchange area for selected operational conditions. The comparison between the model and the experimental results showed a satisfactory convergence for fan frequencies from 50 to 80 Hz. The absolute average deviations of the overall heat transfer coefficient for fan frequencies from 60 to 80 Hz were approximately 10%. With respect to the gas cooler design, a compromise between the bundle area and the refrigerant pressure drop was necessary, resulting in a 2.11 m2 bundle area and 0.23 bar refrigerant pressure drop. In addition, the analysis of the gas cooler’s performance in different ambient temperatures showed that the defined heat exchanger operates properly, compared to other potential gas cooler designs.

Sign in / Sign up

Export Citation Format

Share Document