Experimental studies on the performance of mobile air conditioning system using environmental friendly HFO-1234yf as a refrigerant

2019 ◽  
pp. 095440891988123 ◽  
Author(s):  
Prabakaran Rajendran ◽  
Shaji Sidney ◽  
Iyyappan Ramakrishnan ◽  
Mohan Lal Dhasan
Keyword(s):  
Heat Exchanger ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
Environmental Friendly ◽  
Hfc 134A ◽  
Expansion Valve ◽  
Suction Line ◽  
Suction Line Heat Exchanger

In this work, the experimental investigation on the performance and exergy analysis of mobile air conditioning system with suction line heat exchanger using environmental friendly HFO-1234yf was carried out under varied evaporator air flow rates. The performance was compared with existing HFC-134a results. The performance analysis showed that the cooling capacity and the coefficient of performance of the system with HFO-1234yf were lower than that of the HFC-134a by upto 2–11%. The power consumption and the volumetric efficiency of the compressor with HFO-1234yf were found to be 14.02% and 11.2% higher than that of HFC-134a. From the exergy analysis, it was observed that the major exergy destruction occurred in the compressor, followed by the condenser, evaporator, thermostatic expansion valve, and suction line heat exchanger for both refrigerants. The exergy efficiency of the system with HFO-1234yf was 2.4–12.6% lower than that of HFC-134a. From this study, it was observed that the losses experienced in the compressor, thermostatic expansion valve and evaporator lead to poor performance with HFO-1234yf.

scholarly journals Experimental and Theoretical Study on the Cooling Performance of a CO2 Mobile Air Conditioning System

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1927 ◽  
Author(s):  
Dandong Wang ◽  
Binbin Yu ◽  
Junye Shi ◽  
Jiangping Chen
Keyword(s):  
Air Conditioning ◽  
Theoretical Study ◽  
Cooling Capacity ◽  
Air Conditioning System ◽  
Cooling Performance ◽  
System A ◽  
Hfc 134A ◽  
Expansion Valve ◽  
The Impact ◽  
Compressor Efficiency

CO2 (GWP = 1) is considered as a promising natural alternative refrigerant to HFC-134a in mobile air conditioning (MAC) applications. The objective of this study is to investigate the cooling performance characteristics of a CO2 MAC system. A prototype CO2 MAC system, consisting of a CO2 electrical compressor, CO2 parallel flow microchannel heat exchangers, and an electrical expansion valve, was developed and tested. Factor analysis experiments were conducted to reveal the effect of outdoor temperature on the cooling performance of this CO2 MAC system. Compared with a conventional R134a MAC system, the prototype CO2 MAC system achieved comparable cooling capacity, but had COP reductions of 26% and 10% at 27 °C and 45 °C outdoor conditions, respectively. In addition, based on refrigerant properties, theoretical cycle analysis was done to reveal the impact of evaporator, gas cooler and compressor, on the system cooling performance. It is concluded that the increase of overall compressor efficiency or the decrease of gas cooler approaching temperature could greatly improve the COP of this CO2 MAC system.

EXERGY ANALYSIS OF THE PERFORMANCE OF A VARIABLE REFRIGERANT FLOW (VRF) AIR CONDITIONING SYSTEM

2011 ◽  
Vol 19 (01) ◽  
pp. 57-68 ◽  
Author(s):  
MIGUEL PADILLA
Keyword(s):  
System Performance ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Control Volume ◽  
Hvac Systems ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Air Conditioning System ◽  
Operational Conditions ◽  
Highly Sensitive

Commercial multiple evaporators variable refrigerant flow (VRF) HVAC systems present many advantages such as being energy saving and the capability of adjusting refrigerant mass flow rate according to the change of high rises occurrence. This paper deals with an experimental control volume exergy analysis in a VRF air conditioning system. The experimental results show that the brunt of the total exergy destroyed in the whole system occurs in the outdoor unit, where the exergy destroyed in the condenser is more important. The values of coefficient of performance (COP) obtained for the tests increase as the system reaches operational conditions imposed in every indoor unit zone. The VRF system analyzed is highly sensitive to the action of the constant speed compressor. The use of an inverter compressor improves the system performance by adjusting the power consumption according to the cooling load in the evaporators.

Experimental analysis of the low-GWP refrigerant R1234yf as a drop-in replacement for R134a in a typical mobile air conditioning system

2012 ◽  
Vol 226 (11) ◽  
pp. 2713-2725 ◽  
Author(s):  
Yu Zhao ◽  
Zhaogang Qi ◽  
Jiangping Chen ◽  
Baixing Xu ◽  
Bin He
Keyword(s):  
Working Conditions ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Laminated Plate ◽  
Improve Performance ◽  
Air Conditioning System ◽  
Expansion Valve ◽  
Variable Displacement ◽  
Valve Opening

This study investigated the performance of a typical mobile air conditioning system using R134a and R1234yf as the working fluids under different working conditions. The system is composed of a microchannel parallel flow condenser, a laminated plate evaporator, a variable displacement compressor, and a thermal expansion valve. The different working cycles of each refrigerant were comprehensively compared. The optimum refrigerant charge amount of the R1234yf system was approximately 95% of the R134a system during drop-in tests. The performance of the R134a system was a little higher than that of the R1234yf system. The cooling capacity and system coefficient of performance of the R134a system were 12.4% and 9% larger, respectively. This result is mainly because of the thermophysical property differences between the two refrigerants and the improper expansion valve opening of R1234yf. Analysis on the whole cycle revealed that the R1234yf system could obtain a higher evaporating pressure and a larger superheat and subcooling. Redesigning the expansion valve for R1234yf could improve performance of the system.

Performance Analysis of Heat Pipe Heat Exchanger for Solar Hybrid Desiccant Air-Conditioning System

2015 ◽  
Vol 1115 ◽  
pp. 488-493
Author(s):  
Zuraini Mohd Enggsa ◽  
Arfidian Rachman ◽  
Lisa Nesti ◽  
Sohif Mat ◽  
Kamaruzzaman Sopian
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Air Conditioning ◽  
Cooling System ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
External Power ◽  
Set Up ◽  
Pipe Heat

This paper reports the development of a novel solar hybrid desiccant cooling system with heat pipe heat exchanger (HPHE). The aim is to achieve higher efficiency to reduce the use of electricity by utilizing the desiccant dehumidification system to remove latent load, while the vapour-compression and heat pipe heat exchanger meet the sensible load. Novelty comes as the heat pipe heat exchanger in the system operates efficiently without external power. Experimental set-up has been built by combining the rotary desiccant wheel, heat pipe heat exchanger with a compressive cooling system. Tests are carried out at typical operative ranges for air-conditioning applications, specifically for high hot and humid locations in Bangi, Malaysia. Acetone is used as refrigerant in the HPHE. Performance of HPHE are tested and proven to have direct impact on Coefficient of performance (COP). The results shows good performance of heat pipe heat exchanger efficiency with average efficiency and capacity of 0.65 and 2kw respectively. It is found that the hybrid system can achieve a higher energy performance in hot humid regions.

Experimental Verification of a Universal Accumulator Heat Exchanger Design Procedure Used to Achieve Liquid Overfeeding Effects in Small Air Conditioning Systems

1999 ◽  
Author(s):  
Craig W. Wood ◽  
Josua P. Meyer
Keyword(s):  
Heat Exchanger ◽  
Experimental Verification ◽  
Air Conditioning ◽  
Pressure Ratio ◽  
Design Procedure ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Direct Expansion ◽  
Air Conditioning System ◽  
Heat Exchanger Design

Abstract This study involves the experimental verification of a universal heat exchanger accumulator design procedure. A heat exchange accumulator was manufactured according to a mathematical model developed by the authors and installed into a small air conditioning system. Experimental results show that the addition of the heat exchanger accumulator results in a liquid overfeeding operation that replaces the previously utilized direct expansion operation. It provides an improved air conditioning system that has a 7.5% increase in coefficient of performance and a 4.4% increase in refrigerant mass flow rate. A pressure ratio reduction has a positive effect on the compressor performance and life span. Liquid overfeeding increases the cooling capacity of the system by 6.5%. When compared to direct expansion systems, this basic heat exchanger accumulator provides a reduction in cycling losses and power consumption, an increase in suction pressure and an improvement in isentropic compressor efficiency.

scholarly journals Analisis Numerik Simulasi Kinerja Sistem Tata Udara Unitary Menggunakan Liquid-Suction Heat Exchanger dengan Refrigeran Hidrokarbon

2018 ◽  
Vol 2 (2) ◽  
pp. 11
Author(s):  
Nuriyadi Muhammad
Keyword(s):  
Heat Exchanger ◽  
Air Conditioning ◽  
Environmental Issues ◽  
Coefficient Of Performance ◽  
Coolant Fluid ◽  
Alternative Refrigerant ◽  
Refrigeration System ◽  
Air Conditioning System ◽  
Liquid Line ◽  
Relative Capacity

<p><em>One of the environmental issues to be addressed, particularly in the field of refrigeration and air conditioning, is the destruction of the ozone layer and the effects of global warming due to the use of environmentally inefficient refrigerants. In the field of Refrigeration and Air Conditioning, refrigerant as a cooling medium, plays an important role, and until now there is still the use of refrigerant materials that are not environmentally friendly, generally synthetic refrigerant. One alternative refrigerant replacement against the synthetic refrigerant is hydrocarbon refrigerant (HC). On the other hand, several ways can improve the performance of refrigeration system by lowering the temperature of liquid line using liquid to suction heat exchanger. In this study, a numerical simulation was conducted to examine the effect of using liquid to suction heat exchanger on the performance of a unitary air-conditioning system using hydrocarbon refrigerant as a coolant fluid. The results are, liquid to suction heat exchanger increase refrigeration effect by raising heat exchanger effectivity, the highest increase is about 7%. But the use of LSHX also rises up the compression work by increasing heat exchanger effectivity by 19%. So the Coefficient of performance (COP) and relative capacity index decrease by 5%. Decreasing performance is higher in the unit that operates at higher temperatures.</em></p>

scholarly journals Exergy analysis of scroll compressors working with R22, R407C, and R417A as refrigerant for HVAC system

2009 ◽  
Vol 13 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Sivakumar Kalaiselvam ◽  
Ragupathy Saravanan
Keyword(s):  
Air Conditioning ◽  
Experimental Validation ◽  
Exergy Analysis ◽  
Dynamical Behavior ◽  
Coefficient Of Performance ◽  
Second Law ◽  
Scroll Compressor ◽  
Air Conditioning System ◽  
Available Energy ◽  
Exergy Losses

The rise in crisis of power enthralls the world economically and the options for conventional and non-conventional energy resources have been searched out. No system exists in this world with 100% efficiency due to several irreversibility's. If the output obtained from the system is maximum for a given input, maximum amount of energy can be saved globally. To understand the thermodynamic losses occurring in the system and to predict the available energy that can be tapped from the system, exergy plays a major role. Experimental study on exergy in a system can pave the way to understand the complete behavior of the system exergually. Conceptually exergy studies are based on simulation, to provide a new dimension to the concept of exergy experimental validation have been promoted. The analogy of exergy analysis of three refrigerants working in scroll compressors and their exergual features are explained in this paper. The refrigerants R22, R417A, and R407C and their thermo dynamical behavior, irreversibility were experimented in an air conditioning system with three scroll compressors, interaction between the system and the refrigerant in terms of pressure drop and heat transfer, friction has been implemented for the calculation of exergy. The entire system performance on the basis of refrigerant is validated in each part of the air conditioning system. The resultant coefficient of performance of R407C is 2.41% less than R22 in a R22 designed scroll compressor with minimal exergy losses. The second law efficiency of 50 to 55% obtained in R22 has fewer rules over R407C and R417A which has 48 to 52%. The diminutive deviation of results encourages R417A refrigerant to be used as a substitute for R22. Thus the exergual prediction of performance of refrigerant and second law efficiency can identify the use of eco-friendly refrigerant in scroll compressor.

scholarly journals Experimental and Numerical Design and Optimization of a Counter-Flow Heat Exchanger

2018 ◽  
Vol 151 ◽  
pp. 02003
Author(s):  
Salman Bahrami ◽  
Mohammad Hassan Rahimian
Keyword(s):  
Heat Exchanger ◽  
Air Conditioning ◽  
Cooling System ◽  
Flow Behavior ◽  
Low Pressure ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Counter Flow ◽  
Air Conditioning System ◽  
Flow Heat

A new inexpensive counter-flow heat exchanger has been designed and optimized for a vapor-compression cooling system in this research. The main aim is to experimentally and numerically evaluate the effect of an internal heat exchanger (IHX) adaptation in an automotive air conditioning system. In this new design of IHX, the high-pressure liquid passes through the central channel and the low-pressure vapor flows in several parallel channels in the opposite direction. The experimental set-up has been made up of original components of the air conditioning system of a medium sedan car, specially designed and built to analyze vehicle A/C equipment under real operating conditions. The results show that this compact IHX may achieve up to 10% of the evaporator capacity while low pressure drop will be imposed on this refrigeration cycle. Also, they confirm considerable decrease of compressor power consumption (CPC), which is intensified at higher evaporator air flow. A significant improvement of the coefficient of performance (COP) is achieved with the IHX employment too. The influence of operating conditions has been also discussed in this paper. Finally, numerical analyses have been briefly presented, which bring more details of the flow behavior and heat transfer phenomena, and help to determine the optimal arrangement of channels.

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