Experimental Evaluation of Window-Type Air-Conditioning Unit with New Expansion Device and R404A Alternative Refrigerant

2020 ◽  
Vol 28 (04) ◽  
pp. 2050031
Author(s):  
Ali K. Shaker Al-Sayyab
Keyword(s):  
Experimental Evaluation ◽  
Air Conditioning ◽  
Capillary Tube ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Cycle Model ◽  
Ansys Fluent ◽  
Compressor Power

In this study, the performance of a window-type air-conditioning unit with an alternative, ozone-friendly refrigerant was enhanced by incorporating a nozzle instead of a capillary tube as an expansion device. An experimental evaluation was adopted on a 1.5 RT window-type air-conditioning unit with a controlled environmental zone. According to operating conditions, an ANSYS-Fluent program was used to predict an appropriate nozzle size for a lower pressure ratio. The refrigeration cycle model was simulated using the Engineering Equation Solver (EES).27 The results showed that using a nozzle of 30[Formula: see text]mm length and inner and outer diameters of 9 and 2[Formula: see text]mm, respectively instead of the capillary tube with R404A reduces compressor power consumption by 7.7% and increases the coefficient of performance (COP) by 7.4%.

Performance Enhancement of Window-Type Air-Conditioning Units

2018 ◽  
Vol 26 (02) ◽  
pp. 1850012 ◽  
Author(s):  
Ali K. Shaker Al-Sayyab
Keyword(s):  
Air Conditioning ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Pressure Increase ◽  
Base Case ◽  
Maximum Pressure ◽  
Cycle Model ◽  
Ansys Fluent ◽  
Air Conditioning System ◽  
Compressor Pressure Ratio

In this work, the performance of window-type air-conditioning units was improved. The study was achieved by adding a diffuser at the compressor outlet. An experimental investigation was carried out on 2 RT window-type air-conditioning units with controlled environmental zones. According to the compressor-outlet conditions, an ANSYS-fluent program was used to achieve a suitable diffuser geometry for maximum pressure increase. The refrigeration cycle model was programmed in Engineering Equation Solver (EES). The experimental work shows that using a diffuser of (5[Formula: see text]mm ID [Formula: see text] 9[Formula: see text]mm OD [Formula: see text] 12[Formula: see text]mm L) in an air-conditioning system will decrease the required compressor pressure ratio by 6% from the base case with an overall pressure increase of 1.4 bar and a 29% COP increase from the base case[Formula: see text]

Performance of Ejector Refrigeration Cycle for Automotive Air Conditioning

2016 ◽  
Vol 819 ◽  
pp. 202-206
Author(s):  
Reza Maziar ◽  
Kasni Sumeru ◽  
M.Y. Senawi ◽  
Farid Nasir Ani
Keyword(s):  
Compression Ratio ◽  
Air Conditioning ◽  
The Other ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Entrainment Ratio ◽  
Automotive Air Conditioning ◽  
Average Improvement

In this study, two experiments were performed, one with the conventional compression refrigeration cycle (CRC) and the other with an ejector refrigeration cycle (ERC). The CRC system for automotive air conditioning was designed, fabricated and experiments were conducted. The system was then retrofitted with an ejector as the expansion device and experiments were repeated for the ERC system. Calculations of the entrainment ratio, compressor compression ratio and coefficient of performance (COP) were made for each cycle. The calculations showed that ERC has some advantages over the CRC. In this study, an average improvement of 5% in COP has been obtained for the ERC compared with the CRC.

scholarly journals Design and Thermo-Economic Comparisons of an Absorption Air Conditioning System Based on Parabolic Trough and Evacuated Tube Solar Collectors

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3198 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Air Conditioning ◽  
Thermal Power ◽  
Lithium Bromide ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Parabolic Trough ◽  
Solar Absorption ◽  
Pumping System ◽  
Economic Analyses ◽  
Evacuated Tube

Solar absorption cycles for air conditioning systems have recently attracted much attention. They have some important advantages that aid in reducing greenhouse gas emissions. In this work, design and thermo-economic analyses are presented in order to compare between two different collector types (parabolic trough and evacuated tube) by water–lithium bromide absorption systems, and to select the best operating conditions. Generally, the system consists of three major parts. The first part is the solar field for thermal power conversion. The second part is the intermediate cycle, which contains a flashing tank and pumping system. The third part is the water lithium bromide absorption chiller. A case study for a sports arena with 700–800 kW total cooling load is also presented. Results reveal that a parabolic trough collector combined with H2O–LiBr (PTC/H2O–LiBr) gives lower design aspects and minimum rates of hourly costs (USD 5.2/h), while ETC/H2O–LiBr configuration give USD 5.6/h. The H2O–LiBr thermo-economic product cost is USD 0.14/GJ. The cycle coefficient of performance COP was in the range of 0.5 to 0.9.

scholarly journals Parametric analysis of a combined ejector-vapor compression refrigeration cycle

2020 ◽  
Vol 15 (3) ◽  
pp. 398-408
Author(s):  
I Ouelhazi ◽  
Y Ezzaalouni ◽  
L Kairouani
Keyword(s):  
Current Model ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Constant Area ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

Abstract From the last few years, the use of efficient ejector in refrigeration systems has been paid a lot of attention. In this article a description of a refrigeration system that combines a basic vapor compression refrigeration cycle with an ejector cooling cycle is presented. A one-dimensional mathematical model is developed using the flow governing thermodynamic equations based on a constant area ejector flow model. The model includes effects of friction at the constant-area mixing chamber. The current model is based on the NIST-REFPROP database for refrigerant property calculations. The model has basically been used to determine the effect of the ejector geometry and operating conditions on the performance of the whole refrigeration system. The results show that the proposed model predicts ejector performance, entrainment ratio and the coefficient of performance of the system and their sensitivity to evaporating and generating temperature of the cascade refrigeration cycle. The simulated performance has been then compared with the available experimental data from the literature for validation.

scholarly journals Thermal Performance Analysis of Low-GWP Refrigerants in Automotive Air-Conditioning System

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yousuf Alhendal ◽  
Abdalla Gomaa ◽  
Gamal Bedair ◽  
Abdulrahim Kalendar
Keyword(s):  
Air Conditioning ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Exergy Destruction ◽  
Air Conditioning System ◽  
Capacity Coefficient ◽  
Automotive Air Conditioning ◽  
Automotive Air Conditioning System ◽  
Compressor Power ◽  
Low Global Warming Potential

The energy and exergy of low-global warming potential (GWP) refrigerants were investigated experimentally and theoretically. Refrigerants with a modest GWP100 of  ≤ 150 can be sufficient for bringing down emissions which were concerned for the automotive air-conditioning system. Three types of low-GWP refrigerants, R152a, R1234yf, and R1234ze(E), were examined with particular reference to the current high-GWP of R134a. The effect of different evaporating and condensing temperatures in addition to compressor speed was considered. The purpose was to bring a clear view of the performance characteristics of possible environment friendly alternatives of R134a. The analysis was carried out with compressor power, cooling capacity, coefficient of performance, exergy destruction, and exergy efficiency. It was noted that the total exergy destruction of R1234yf was reduced by 15% compared to that of R134a. The refrigerant R1234ze(E) has the highest energetic and exergetic performance compared with the other investigated refrigerants.

A Field Study of a Low-Flow Internally Cooled/Heated Liquid Desiccant Air Conditioning System: Quasi-Steady and Transient Performance

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Ahmed H. Abdel-Salam ◽  
Chris McNevin ◽  
Lisa Crofoot ◽  
Stephen J. Harrison ◽  
Carey J. Simonson
Keyword(s):  
Air Conditioning ◽  
Field Performance ◽  
Ambient Air ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Low Flow ◽  
Transient Field ◽  
Liquid Desiccant ◽  
Internally Cooled ◽  
Steady Performance

The field performance of a low-flow internally cooled/heated liquid desiccant air conditioning (LDAC) system is investigated in this paper. The quasi-steady performance (sensible and latent heat transfer rates, coefficient of performance (COP), and uncertainties) of the LDAC system is quantified under different ambient air conditions. A major contribution of this work is a direct comparison of the transient and quasi-steady performance of the LDAC system. This paper is the first to quantify the importance of transients and shows that, for the environmental and operating conditions in this paper, transients can be neglected when estimating the energy consumption of the LDAC system. Another major contribution of this work is the development and verification of a new method that quantifies (with acceptable uncertainties) the quasi-steady performance of a LDAC system from transient field data using average data.

Evaluation of Cooling Water Storage for Liquid-Desiccant Air Conditioning System

2014 ◽  
Author(s):  
Danial Salimizad ◽  
Chris McNevin ◽  
Stephen Harrison
Keyword(s):  
Air Conditioning ◽  
Electrical Power ◽  
Water Storage ◽  
Cooling Water ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Liquid Desiccant ◽  
Air Conditioning System ◽  
Electrical Power Consumption ◽  
Evaporative Cooling Tower

Liquid-desiccant (LD) dehumidification technology has been used to extract moisture from humid air while attempting to consume less electricity than traditional air-conditioning methods. An evaporative cooling tower (ECT) was used as a cooling device to reject the latent heat gained by the system to regenerate the desiccant solution. The performance of an ECT was evaluated both experimentally and through TRNSYS simulations to investigate optimal operating conditions. The ECT often operated in humid conditions which resulted in reduced heat rejection rates and ineffective operation. To improve performance, cooling water storage (CWS) was investigated as a way to reduce ECT usage during periods of higher ambient humidity. To undertake this study, the complete LD system, incorporating CWS, was modelled in TRNSYS for a range of typical operating conditions. The results indicated that operation of the CWS system reduced the electrical power consumption and increased the electrical coefficient of performance (COPE) of the liquid desiccant air conditioning unit system by up to 16%. The total cooling rate improved by up to 6%. Smaller gains in COPT and solar fraction were also found in the simulation results.

A Study on the Combined Driven Refrigeration Cycle Using Ejector

2021 ◽  
pp. 2150004
Author(s):  
Waseem Raza ◽  
Gwang Soo Ko ◽  
Youn Cheol Park
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Primary Source ◽  
Mechanical Efficiency ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Working Fluid ◽  
Low Grade ◽  
Refrigeration Cycle ◽  
R 134A

The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4[Formula: see text]mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.

Research on the Application of Alternative Refrigerants R407C and R410A in Refrigeration-Type Compressed-Air Dryers

2014 ◽  
Vol 672-674 ◽  
pp. 1739-1742
Author(s):  
Hui Liu ◽  
Jin Hua Li ◽  
Hong Xiao
Keyword(s):  
Working Condition ◽  
Pressure Ratio ◽  
Environmentally Friendly ◽  
Compressed Air ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Alternative Refrigerants ◽  
Percentage Points ◽  
Refrigeration Capacity ◽  
Air Dryer

The coefficient of performance (COP), the volumetric refrigeration capacity and the pressure ratio of refrigeration cycle were studied in a refrigeration-type compressed-air dryer using environmentally friendly refrigerants R410A and R407C and compared with those using R22. Study indicates that under the working condition of a refrigeration-type compressed-air dryer, COP using R410A is 3% higher than that using R407C, the volumetric refrigeration capacity using R410A is 50 percentage points higher than that using R407C and the pressure ratio of R410A is 10% less than that of R407C. COP using R410A equals 96% of that using R22 and the volumetric refrigerating capacity equals 147% of that using R22. COP using R407C is equal to 93% of that using R22 and the volumetric refrigerating capacity is equal to 97% of that using R22. R410A is a more appropriate alternative to R22 than R407C in a refrigeration-type compressed-air dryer.

scholarly journals Experimental Investigation of a Split Air Conditioning Using Condensate as Direct Evaporative Cooling

2021 ◽  
Vol 86 (1) ◽  
pp. 140-153
Author(s):  
Azridjal Aziz ◽  
Muhammad Rif’at Syahnan ◽  
Afdhal Kurniawan Mainil ◽  
Rahmat Iman Mainil
Keyword(s):  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Air Conditioner ◽  
Direct Evaporative Cooling ◽  
Compressor Power ◽  
Discharge Pressure ◽  
Air Conditioning Systems

Split air conditioning systems produce reasonable amount of condensate which is usually not utilized and thrown away to the environment. On the other hand, it consumes a lot of energy during operation. The aim of this study is to investigate the improvement of air conditioning systems performance utilizing condensate. A direct evaporative cooling using condensate is incorporated on a 0.74 ton-cooling capacity of split air conditioning to decrease the air temperature before entering the condenser. Performances of the split air conditioning with and without direct evaporative cooling are compared and presented in this paper. The results show that the use of direct evaporative cooling using condensate into the air before passing through the condenser reduces the compressor discharge pressure. The decrease of the condenser pressure led to 4.7% and 7% reduction of power consumption for air conditioner without cooling load and air conditioner with 2000 W cooling load, respectively. The cooling effect and coefficient of performance (COP) increase with the decrease of compressor power. The use of direct evaporative cooling with condensate into the air before entering the condensing system can enhance the system performance and protect the environment.

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