scholarly journals A New Design of an Integrated Solar Absorption Cooling System Driven by an Evacuated Tube Collector: A Case Study for Baghdad, Iraq

2020 ◽  
Vol 10 (10) ◽  
pp. 3622 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Thermal Performance ◽  
Air Conditioning ◽  
Cooling System ◽  
Electrical Power ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Solar Fraction ◽  
Design Variables

The electrical power consumption of refrigeration equipment leads to a significant influence on the supply network, especially on the hottest days during the cooling season (and this is besides the conventional electricity problem in Iraq). The aim of this work is to investigate the energy performance of a solar-driven air-conditioning system utilizing absorption technology under climate in Baghdad, Iraq. The solar fraction and the thermal performance of the solar air-conditioning system were analyzed for various months in the cooling season. It was found that the system operating in August shows the best monthly average solar fraction (of 59.4%) and coefficient of performance (COP) (of 0.52) due to the high solar potential in this month. Moreover, the seasonal integrated collector efficiency was 54%, providing a seasonal solar fraction of 58%, and the COP of the absorption chiller was 0.44, which was in limit, as reported in the literature for similar systems. A detailed parametric analysis was carried out to evaluate the thermal performance of the system and analyses, and the effect of design variables on the solar fraction of the system during the cooling season.

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.

Modeling, Simulation and Optimization of a Solar Absorption Air Conditioning System for an Office Block in Zaria, Nigeria

2016 ◽  
Vol 24 (02) ◽  
pp. 1650012 ◽  
Author(s):  
T. O. Ahmadu ◽  
C. O. Folayan ◽  
F. O. Anafi
Keyword(s):  
Energy Demand ◽  
Air Conditioning ◽  
Meteorological Data ◽  
Coefficient Of Performance ◽  
System Component ◽  
Time Step ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Simulation And Optimization ◽  
Cooling Energy Demand

In this study, a solar absorption air conditioning system has been modeled simulated and optimized for an office block covering a total floor area of 90[Formula: see text]m2using the TRNSYS 16 software. Meteorological data over a period of a typical year for Zaria in Nigeria where the office block is located was used in the simulation and optimization. The hourly cooling energy demand of the office block for the whole year was simulated using the TRNSYS sub program TRNbuild. The peak cooling energy demand was used to size the components of the solar absorption air conditioning system. Based on the initial sizes, a TRNSYS model of the air conditioning system was developed. The simulation and optimization process was done by employing a monthly average data approach in which the TRNSYS software was combined with Microsoft excel. The simulation was done on an hourly time step, optimization was done by studying effect of varying system component sizes on performance indices: coefficient of performance (COP), solar coefficient of performance (SCOP) and solar fraction (SF). Results indicate that the system is capable of attaining an average annual SF of 0.79 in the given location.

scholarly journals System Design of Solar Absorption Cooling : A Case Study in Building of Engineering Physics Department UGM

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 22
Author(s):  
Andang Widiharto ◽  
Didit Setyo Pamuji ◽  
Atik Nurul Laila ◽  
Fiki Rahmatika Salis ◽  
Luthfi Zharif ◽  
...  
Keyword(s):  
Global Warming ◽  
Solar Collector ◽  
Air Conditioning ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Coefficient Of Performance ◽  
Thermal Coefficient ◽  
Solar Absorption ◽  
Absorption Cooling ◽  
Solar Absorption Cooling

<p>Air conditioning (AC) is one of the most building’s energy consumer, included in building of Engineering Physisc’s Departement, Universitas Gadjah Mada (UGM). The declining of fossil fuel reserves and the increasing effects of global warming, forcing the world to switch to renewable energy sources. This paper discusses the design of solar absorption cooling system to replace conventional AC in seven lecture halls of Engineering Physic’s Departement, UGM. There are some steps that have been done to design the solar absorption cooling, i.e. do a study of the potential availability of solar energy, calculate the cooling loads, analyze the thermodynamic process of the system, determine the type of collector to be used and calculate area of solar collector needed. The thermal coefficient of performance (COP) of the system designed was about 0.84 which could use some types of flat plate solar collector with each area corresponding to each efficiency values. </p><p><strong>Keyword</strong> : Air conditioning; global warming; solar absorption cooling; solar collector</p>

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.

Thermoelectric Air-Conditioning System: Building Applications and Enhancement Techniques

2019 ◽  
Vol 27 (02) ◽  
pp. 1930002 ◽  
Author(s):  
Aklilu Tesfamichael Baheta ◽  
Kar Kin Looi ◽  
Ahmed Nurye Oumer ◽  
Khairul Habib
Keyword(s):  
Air Conditioning ◽  
Phase Change Materials ◽  
Cooling System ◽  
High Reliability ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Future Research ◽  
Thermoelectric Cooling ◽  
Air Conditioning System ◽  
System Building

The high reliability, the absence of working fluid and auxiliary pipes in the thermoelectric cooling application have attracted the attention of researchers in the last two decades. However, the use of thermoelectric air-conditioning system for building application has not been entirely explored due to its low coefficient of performance (COP) compared to the conventional air conditioning system. To overcome this primary limitation, different COP enhancement techniques of thermoelectric for air conditioning system building application are made available. This paper provides the recent development of thermoelectric air conditioning system in building applications, such as thermoelectric radiant panel ceiling, thermoelectric air duct system and thermoelectric cooling facades. It also provides the different strategies to enhance its performance in order to fit this technology in real building applications such as the integration of water-cooling system, phase change materials, evaporator cooling system and nanofluid micro-channel heat sinks. Lastly, the challenges of thermoelectric air-conditioning systems and future research directions are discussed.

scholarly journals Alternative Air-Conditioning Options for Developing Countries

2017 ◽  
Vol 2 (1) ◽  
pp. 76 ◽  
Author(s):  
Muhammad Kashif ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Developing Countries ◽  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Individual Characteristics ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
Evaporative Cooling System

This study assesses the potential selection of efficient air-conditioning (AC) and cooling systems in order to avoid excess power consumption, mitigation of harmful refrigerants generated by the existing AC systems. Several varieties of active and passive air-conditioning systems i.e. heating ventilating air-conditioning (HVAC), vapor compression air-conditioning (VCAC) conventional direct evaporative cooling (DEC) and indirect evaporative cooling (IEC)  and desiccant air-conditioning (DAC) systems are under practice for the cooling and dehumidification. The storage of agricultural products mainly based on product individual characteristics i.e. respiration rate, transpiration rate and moisture content of that product. Variant ambient air conditions and the type of application are the main parameters for the choice of air-conditioning system to get optimum performance. The DAC system subsidize the coefficient of performance (COP) in humid regions, coastal ranges of developing countries e.g. Karachi and Gawadar (Pakistan) with hot humid climatic conditions. In similar way, hottest regions of the country such as Sibbi, Jacobabad and Multan perform better results when incorporates with M-cycle evaporative cooling system. Variation in ambient air conditions directly affect the cooling load and the choice of sustainable air-conditioning system

scholarly journals Air Conditioning System Performance of a City Hotel Appraised for Energy Use Efficiency

2021 ◽  
Vol 83 (1) ◽  
pp. 118-139
Author(s):  
I Made Rasta ◽  
I Nyoman Suamir
Keyword(s):  
Air Conditioning ◽  
Energy Use ◽  
Energy Performance ◽  
Efficiency Index ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Air Conditioning System ◽  
Use Efficiency ◽  
Ac Systems ◽  
System Selection

This paper presents results of a study on split air conditioning (AC) performance of a city hotel in Bali, Indonesia. The study applied a practical global approach to appraising the performance of existing AC systems and their installation in a city hotel. The results obtained indicate that improper AC system selection and installation potentially reduces their energy performance which include COP (coefficient of performance), EER (energy efficiency ratio), and SEI (system efficiency index). The finding also shows that improper system selection and installation has damaged 54 unit compressors of 90 AC systems installed in a particular building within three years’ period. Overall number of compressors that have been damaged in three years can reach 76 units accounted for about 23.1% of the total AC systems installed in the hotel. It is also found a reduction on AC system cooling capacity.

Performance Test on a Solar Powered Two-Stage Solid Wheel Desiccant Air Conditioning System

2013 ◽  
Vol 732-733 ◽  
pp. 609-614
Author(s):  
Tong Hua Zou ◽  
Gu Jia ◽  
Fa Li Cao ◽  
Rong Yu
Keyword(s):  
Relative Humidity ◽  
Air Conditioning ◽  
Performance Test ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Outlet Temperature ◽  
Thermal Coefficient ◽  
Two Stage ◽  
Air Conditioning System ◽  
Solar Powered

In the paper, changes of both outlet temperature and relative humidity of solar powered two-stage wheel desiccant air conditioning system are tested with time under the typical Tianjin summer condition. It is found that supply air temperature of the solar driven desiccant cooling system could steady below 21 degrees Celsius, and the relative humidity of it is more than sixty percent in most of time of the actual operation. When operating, the thermal coefficient of performance of the whole air conditioning unit is about 0.5, and the reliability of two-stage wheel desiccant air conditioning system is verified.

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.

PERFORMANCE OF SOLAR-ASSISTED ABSORPTION CYCLE AIR CONDITIONING SYSTEM

2016 ◽  
Vol 78 (11) ◽  
Author(s):  
Zakaria Jusoh ◽  
Wan Mohd Faizal Wan Mahmood ◽  
Mohd Radzi Abu Mansor
Keyword(s):  
Air Conditioning ◽  
Lithium Bromide ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Small Scale ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Cycle System ◽  
Absorption Cycle ◽  
Evacuated Tube

A study of the efficiency of the cycle of solar assisted absorption air conditioning system has been carried out. The absorption cycle system has been in operation in Malaysia, but only in large buildings such as the KL International Airport, government buildings in Putrajaya and KLCC buildings. This study focuses on a small-scale lithium-bromide (LiBr) absorption cycle air conditioning system for residential application. The important component of the system has been designed with the capacity of 3.517 kW cooling load suitable for small-capacity application. Generator, condenser, evaporator and absorber have been designed, fabricated, assembled and tested in the laboratory. A total of ninety-pieces of evacuated tube solar collectors have been installed to produce hot water to be used as a heat source to separate the absorbent and refrigerant. Lithium bromide-water pair was used in this experiment. With the concentration of lithium bromide of 33%, the average coefficient of performance (COP) obtained was 0.446, 0.438 and 0.431 for category A, category B and category C respectively. This study shows that the cycle of solar absorption air conditioning system in small scale can be used in Malaysia and tropical climate countries. 

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