Solar Refrigerating Systems

2013 ◽  
Vol 772 ◽  
pp. 581-586 ◽  
Author(s):  
Ioan Sarbu ◽  
Emilian Valea ◽  
Calin Sebarchievici
Keyword(s):  
Solar Energy ◽  
Cooling System ◽  
Environmental Issues ◽  
Coefficient Of Performance ◽  
Practical Applications ◽  
Solar Cooling ◽  
Important Research Topic ◽  
Absorption Cycle ◽  
Thermal Cooling ◽  
Ejector Cycle

Along with the global warming impacts and climate changes, the demands for air conditioning and refrigeration have increased. Therefore, providing cooling by utilizing renewable energy such as solar energy is a key solution to the energy and environmental issues. In this paper are presented theoretical basis and practical applications for cooling technologies assisted by solar energy and their recent advances. The ejector cycle represents the thermo-mechanical cooling system, and has a higher coefficient of performance (COP) but require a higher heat source temperature than other cycles. Based on the thermal COP of each cycle, the absorption cycle which represents the thermal cooling is preferred to the ejector cycle. Next to improving efficiency of solar cooling technologies, research on advanced solar collector is the most important research topic.

Feasibility of Usage Possibility in Turkey of Solar Driven Ejector-Absorption Cooling System

Solar Energy ◽  
2004 ◽  
Author(s):  
Adnan So¨zen ◽  
H. Serdar Yu¨cesu
Keyword(s):  
Solar Energy ◽  
Cooling System ◽  
Sunshine Duration ◽  
Meteorological Data ◽  
Minimum Energy ◽  
Montreal Protocol ◽  
Coefficient Of Performance ◽  
Promising Alternative ◽  
Absorption Cooling ◽  
Yearly Average

It appears that solar assisted refrigeration systems are a promising alternative to the conventional electrical driven units. Their main advantages are the reduction of peak loads for electricity utilities, the use of zero ozone depletion impact refrigerants, the decreased primary energy consumption, and decreased global warming impact. In this study, we have investigated the possibility of using ejector-absorption cooling systems (EACS) in Turkey. In addition, this study determines whether or not required heat for generator of EACS can be obtained from solar energy in Turkey. There are two important reasons to explain the use of EACS in Turkey. One is that the production and use of the CFCs and HCFCs will be phased out according to Montreal Protocol. The second is that, in Turkey, solar energy potential is very high due to its location in the northern hemisphere with latitudes 36–42°N and longitudes 26–45°E, the yearly average solar radiation is 3.6 kWh/m2 day, and the total yearly radiation period is ∼2610 h. The radiation data and sunshine duration information collected since 2000 for 17 cities are used for analysis in different regions of Turkey. For maximum coefficient of performance (COPmax) conditions of EACSs operated with aqua-ammonia, it is found that required optimum collector surface area was defined by using the meteorological data. In addition since the system can be used throughout the year, required minimum energy for auxiliary heater was also calculated. It is shown that the heat gain factor (HGF) varies in the range from 0.5 to 2.68 for the all the seasons in the selected cities. The maximum HGF is 2.68 for Van in July. This study shows that there is a great potential for utilisation of solar cooling system for domestic heating/cooling applications in Turkey.

Analysis of an Adsorption Chiller Cooling System for Various Types of Solar Collectors Using the F-Chart Cooling Method

2016 ◽  
Author(s):  
I. P. Koronaki ◽  
E. G. Papoutsis ◽  
M. T. Nitsas
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Cooling System ◽  
Energy Performance ◽  
Electrical Network ◽  
Climatic Data ◽  
Solar Collectors ◽  
Adsorption Chiller ◽  
Solar Cooling ◽  
Cooling Method

Solar cooling systems offer a reliable and environmentally friendly alternative to conventional electrically driven vapor compression cooling units. Air conditioning systems powered by solar energy are very attractive because they have zero ozone depletion and global warming potential, their operational cost is low and they do not burden the electrical network during summer months. In this study, the installation of a solar cooling system in various Greek cities is examined. The system utilizes a single-stage, two-bed silica gel-water adsorption chiller driven by heat produced by solar collectors. A lumped parameter model is used to simulate the performance of the adsorption chiller. The optimum tilt of the solar collectors is calculated for each examined city in order for the collected solar energy to be maximized during the summer period (April to September). The climatic data are taken from the technical notes of Greek Regulation for Buildings Energy Performance. Then, using the f-chart cooling method the necessary collectors’ surface area is estimated for every examined city and for different types of flat plate collectors (including advanced flat plate, simple flat plate and hybrid photovoltaic thermal collectors).

Research of Combined Heating and Cooling by Solar Ground-Source Heat Pump and PCM Thermal Storage

Solar Energy ◽  
2005 ◽  
Author(s):  
Li-Xia Wu ◽  
Mao-Yu Zheng
Keyword(s):  
Heat Exchanger ◽  
Solar Energy ◽  
Cooling System ◽  
Storage System ◽  
Thermal Storage ◽  
Cold Climate ◽  
Coefficient Of Performance ◽  
Tube Heat Exchanger ◽  
Heating And Cooling ◽  
Ground Source

In severely cold climate, significant amount of energy is used to heat buildings. Both the theoretical computation and experiments show that it is difficult and uneconomical to use solar energy collected merely in winter. A new method has been developed to store solar energy during summer, fall, and spring for winter heating. This paper presents in details the combined heating and cooling system by solar ground-source heat pump (GSHP) and short-term phase change material (PCM) thermal storage. The hybrid system and season-shift mode can make the sustainable use of solar energy possible. As for the above system, the solar energy collected is stored into soil through the U-tube heat exchanger. In winter, the thermal energy is taken out for heating using the GSHP. At the end of the heat supply season, the underground soil temperature may drop below 0°C. Then some heat exchangers begin to store the heat into soil while others stop. In summer, the U-tube heat exchanger is used to produce low temperature water without compressor to cool the room. The project was supported by the Energy Conservation Laboratory at Harbin Institute of Technology (HIT). The whole systems, which have run for over two years, consist of a flat plate solar hot water system installed on the roof, a soil thermal storage system, a GSHP system, a PCM thermal storage system and heating-cooling system. The measured results show an average heating coefficient of performance (COP) of 3.2 in winter and the cooling coefficient of performance (COP) of 18.0 in summer. The PCM thermal storage system has been investigated by numerical simulation and experiments in the cold climate. In most time of winter, the PCM thermal storage system was used to supply heat, while solar GSHP was also used during continuous cloudy days and severely cold days. The result shows that above method is feasible. The most advantage of this system is that it does not need the usual energy equipment. The numerical analysis has been used to investigate the thermal energy balance of the underground soil. The variation of the soil temperature field around the U-tube heat exchanger has also been studied, not only for the single exchanger but also for multiple exchangers. The underground soil makes the yearly thermal balance possible because the solar energy supplies the heat that is extracted from the soil for heating in winter. Then this system can operate for a long period.

Simulation and Optimization of Solar Thermal Cooling System in Manufacturing Research Center Building to Reduce Operational Cost Using Software EnergyPlus and GenOpt

2015 ◽  
Vol 780 ◽  
pp. 81-86 ◽  
Author(s):  
Nasruddin ◽  
K. Rahadian ◽  
M.I. Alhamid ◽  
Arnas
Keyword(s):  
Cooling System ◽  
Solar Thermal ◽  
Research Center ◽  
Operational Cost ◽  
Water Heater ◽  
Air Conditioning System ◽  
Simulation And Optimization ◽  
Solar Thermal Cooling ◽  
Absorption Cycle ◽  
Thermal Cooling

Solar Thermal Cooling System with its absorption cycle is expected to replace the conventional air conditioning system with vapor compression cycle because it is more efficient in terms of cost and energy. However, due to the heat of the sun is not always stable, the system needs to be equipped with a backup energy source, one of which is CNG. In the Manufacturing Research Center building, the lack of facilities that support availability of CNG causes large operational cost. Therefore, optimization efforts with the aim to reduce operational cost are needed. Simulation and optimization performed with EnergyPlus and GenOpt. The conclusion is that the installation of 187.5 kW electric tankless water heater is able to reduce total operational cost by 34.65% compared to system that uses combination of solar thermal and CNG and 49.69% compared with system that uses only CNG.

Investigation of optimization of solar energy refrigerator with natural humidifier

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Santosa I D. M. C. ◽  
Waisnawa I N. G. S. ◽  
Sunu P. W. ◽  
Wirajati I G. A. B.
Keyword(s):  
Solar Energy ◽  
Cooling System ◽  
Ambient Air ◽  
Operating Conditions ◽  
Cold Chain ◽  
Coefficient Of Performance ◽  
Good Reliability ◽  
Tropical Country ◽  
Temperature And Humidity ◽  
Horticultural Products

Cold chain processes of horticultural products in tropical countries is very urgent to maintain product quality. In Indonesia, the temperature and humidity are relatively high, so that the deterioration of horticultural products is very fast. Because of the high humidity, this condition can highly possibly use a natural humidifier for a cold room by purging humid ambient air to the refrigerator cabin with the best certain time. Meanwhile, as a tropical country, solar energy has good reliability to be developed. This study aims to determine the performance of the medium temperature refrigerator with a natural humidifier using solar energy as energy source. This research was conducted as an experimental investigation. The rig has been built completely with measurements and instrumentation for precise temperature and humidity control. The results showed that the system reached a quite good coefficient of performance (COP), with the thermodynamically COP of 3.6. However, humidifiers contribute a cooling load which can affect the temperature increase of 1o C - 1.5o C in the cooling system. Further studies will examine the optimization of the refrigerator system with natural humidifiers with low electricity consumption and eco-operating conditions with the best combination of temperature and humidity to keep the product of good quality in a long storage time.

Numerical Analysis of Heat and Mass Transfer in an Annular Porous Adsorber for Solar Cooling System

2010 ◽  
Vol 297-301 ◽  
pp. 802-807
Author(s):  
Nadia Allouache ◽  
Rachid Bennacer ◽  
Salahs Chikh ◽  
A. Al Mers
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
System Performance ◽  
Technology Development ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Cooling Systems ◽  
Solar Cooling ◽  
Adsorbed Quantity ◽  
Solar Cooling System

The present study deals with a solid adsorption refrigerator analysis using activated carbon/methanol pair. It is a contribution to technology development of solar cooling systems. The main objective consists to analyse the heat and mass transfer in an annular porous adsorber that is the most important component of the system. The porous medium is contained in the annular space and the adsorber is heated by solar energy. A general model equation is used for modelling the transient heat and mass transfer. Effects of the key parameters on the adsorbed quantity, the coefficient of performance, and thus on the system performance are analysed and discussed.

Comparative Analysis of Solar Thermal Cooling and Solar Photovoltaic Cooling Systems

2011 ◽  
Author(s):  
N. Fumo ◽  
V. Bortone ◽  
J. C. Zambrano
Keyword(s):  
Energy Consumption ◽  
Fossil Fuels ◽  
Cooling System ◽  
Solar Thermal ◽  
Solar Photovoltaic ◽  
Solar Thermal Energy ◽  
Cooling Systems ◽  
Solar Cooling ◽  
Solar Thermal Cooling ◽  
Thermal Cooling

The Energy Information Administration of the United States Department of Energy projects that more than 80% of the energy consumption of the U.S. by 2035 will come from fossil fuels. This projection should be the fuel to promote projects related to renewable energy in order to reduce energy consumption from fossil fuels to avoid their undesirable consequences such as carbon dioxide emissions. Since solar radiation match pretty well building cooling demands, solar cooling systems will be an important factor in the next decades to meet or exceed the green gases reduction that will be demanded by the society and regulations in order to mitigate environmental consequences such as global warming. Solar energy can be used as source of energy to produce cooling through different technologies. Solar thermal energy applies to technology such as absorption chillers and desiccant cooling, while electricity from solar photovoltaic can be used to drive vapor compression electric chillers. This study focuses on the comparison of a Solar Thermal Cooling System that uses an absorption chiller driven by solar thermal energy, and a Solar Photovoltaic Cooling System that uses a vapor compression system (electric chiller) driven by solar electricity (solar photovoltaic system). Both solar cooling systems are compared against a standard air cooled cooling system that uses electricity from the grid. The models used in the simulations to obtain the results are described in the paper along with the parameters (inputs) used. Results are presented in two figures. Each figure has one curve for the Solar Thermal Cooling System and one for the Solar Photovoltaic Cooling System. One figure allows estimation of savings calculated based the net present value of energy consumption cost. The other figure allows estimating primary energy consumption reduction and emissions reduction. Both figures presents the result per ton of refrigeration and as a function of area of solar collectors or/and area of photovoltaic modules. This approach to present the result of the simulations of the systems makes these figures quite general. This means that the results can be used to compare both solar cooling systems independently of the cooling demand (capacity of the system), as well as allow the analysis for different sizes of the solar system used to harvest the solar energy (collectors or photovoltaic modules).

scholarly journals Study and Analysis by Numerical Simulation of a Solar Continuous Adsorption Chiller

2015 ◽  
Vol 773-774 ◽  
pp. 605-609
Author(s):  
Rabah Gomri ◽  
Billel Mebarki
Keyword(s):  
Solar Energy ◽  
Cooling System ◽  
Recovery Process ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Solar Collectors ◽  
Adsorption Refrigeration ◽  
Continuous Adsorption ◽  
Adsorption Cooling System ◽  
Mass Recovery

Environment and energy problems over the world have motivated researchers to develop energy systems more sustainable, having as one of the possible alternative the use of solar energy as source for cooling systems. Adsorption refrigeration systems are regarded as environmentally friendly alternatives to conventional vapour compression refrigeration systems, since they can use refrigerants that do not contribute to ozone layer depletion and global warming. In this paper a performance comparison between a solar continuous adsorption cooling system without mass recovery process and solar continuous adsorption cooling system with mass recovery process is carried out. Silica-Gel as adsorbent and water as refrigerant are selected. The results show that the adsorption refrigeration machine driven by solar energy can operate effectively during four months and is able to produce cold continuously along the 24 hours of the day. The importance of the mass recovery is proved in this study by increasing the coefficient of performance and the cooling capacity produced. For the same cooling capacity produced, the required number of solar collectors with mass recovery system is lower than the required number of solar collectors in the case of the refrigeration unit without mass recovery. For the same cooling capacity the system with mass recovery process allowed lower generation temperature.

Performance of a Solar Desiccant Cooling System

1988 ◽  
Vol 110 (3) ◽  
pp. 165-171 ◽  
Author(s):  
George O. G. Lo¨f ◽  
Gerald Cler ◽  
Thomas Brisbane
Keyword(s):  
Heat Exchange ◽  
Solar Energy ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Hot Water ◽  
Colorado State University ◽  
Energy Applications ◽  
Solar Cooling ◽  
Cooling Unit ◽  
Electric Boiler

A solar desiccant cooling system was operated at the Solar Energy Applications Laboratory, Colorado State University, throughout the 1986 summer. The system comprises an American Solar King fresh air heating/desiccant evaporative cooling unit, a Sunmaster evacuated tube solar collector, hot water solar storage tank, auxiliary electric boiler, controls, and accessories. The cooling unit is operated in the ventilation mode, fresh air being dried in a rotating desiccant matrix, and cooled by heat exchange and evaporative cooling. Return air is used as a cooling medium in a rotating heat exchange matrix, heated by solar energy in a heat exchange coil, and discarded through the rotating desiccant bed. The solar-driven system provided over 90 percent of the seasonal cooling requirements in an experimental, residence type building at average COP levels of 1.0 and solar collection efficiencies of 50 percent when supplied with solar heated water at temperatures of 50 to 65° C. Detailed operating results, including total and average solar cooling provided, coefficients of performance, and overall solar cooling performance ratios are presented.

scholarly journals Contribution to the study of combined adsorption–ejection system using solar energy

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771185
Author(s):  
Amal Bel Haj Jrad ◽  
Mohamed Bechir Ben Hamida ◽  
Rabie Ghnay ◽  
Abdallah Mhimid
Keyword(s):  
Activated Carbon ◽  
Solar Energy ◽  
Simulation Software ◽  
Coefficient Of Performance ◽  
Comsol Multiphysics ◽  
Solar Cooling ◽  
Model And Simulation ◽  
Time Space ◽  
Mass Transfers ◽  
The City

Solar energy is a renewable and free energy. We can take advantage of such characteristics to produce solar cooling through adsorption especially in an area such as the city of Monastir, Tunisia, where the Sun is abundant. A mathematical model and simulation are carried out to optimize heat and mass transfers performance in a flat solar collector using zeolite/water and activated carbon/methanol pairs during desorption phenomena. A commercial simulation software COMSOL Multiphysics has been developed to provide us with the time–space evolution of temperature and average fluid content. Numerical results have shown that the activated carbon desorbs faster than the zeolite. Besides, in order to get an important solar coefficient of performance, it is necessary to have an important incident solar energy. It has also been found that to improve the solar coefficient of performance, an adsorption–ejection system is statically studied.

Sign in / Sign up

Export Citation Format

Share Document