Theoretical and Experimental Research Regarding Operating Conditions of the Refrigeration Absorption/Adsorption Machines Using Solar Energy

2014 ◽  
Vol 659 ◽  
pp. 325-330 ◽  
Author(s):  
Bogdan Caciula ◽  
Tanase Panait ◽  
Viorel Popa
Keyword(s):  
Solar Energy ◽  
Experimental Research ◽  
Mediterranean Climate ◽  
Cooling System ◽  
Operating Conditions ◽  
Cooling Systems ◽  
Solar Cooling ◽  
Optimum Dimension

In this article is presents a short analyze of a solar cooling systems using absorption and adsorption chillers. We try to pick the optimum dimension for the principal equipment of a cooling system for a holiday house place in Mediterranean climate using TRNSYS software.

Remote Heat Pipe Based Heat Exchanger Performance in Notebook Cooling

2005 ◽  
Author(s):  
Seyyed Khandani ◽  
Himanshu Pokharna ◽  
Sridhar Machiroutu ◽  
Eric DiStefano
Keyword(s):  
Heat Exchanger ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Cooling System ◽  
Temperature Drop ◽  
Operating Conditions ◽  
Cooling Systems ◽  
Temperature Variations ◽  
Non Linear ◽  
Condenser Temperature

Remote heat pipe based heat exchanger cooling systems are becoming increasingly popular in cooling of notebook computers. In such cooling systems, one or more heat pipes transfer the heat from the more populated area to a location with sufficient space allowing the use of a heat exchanger for removal of the heat from the system. In analsysis of such systems, the temperature drop in the condenser section of the heat pipe is assumed negligible due to the nature of the condensation process. However, in testing of various systems, non linear longitudinal temperature drops in the heat pipe in the range of 2 to 15 °C, for different processor power and heat exchanger airflow, have been measured. Such temperature drops could cause higher condenser thermal resistance and result in lower overall heat exchanger performance. In fact the application of the conventional method of estimating the thermal performance, which does not consider such a nonlinear temperature variations, results in inaccurate design of the cooling system and requires unnecessarily higher safety factors to compensate for this inaccuracy. To address the problem, this paper offers a new analytical approach for modeling the heat pipe based heat exchanger performance under various operating conditions. The method can be used with any arbitrary condenser temperature variations. The results of the model show significant increase in heat exchanger thermal resistance when considering a non linear condenser temperature drop. The experimental data also verifies the result of the model with sufficient accuracy and therefore validates the application of this model in estimating the performance of these systems.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

scholarly journals Physicochemical characteristics of solid particles of contaminants in the coolant of automobile and tractor engines

2021 ◽  
Vol 1 (3) ◽  
pp. 53-61
Author(s):  
S.G. Dragomirov ◽  
◽  
P.Ig. Eydel ◽  
A.Yu. Gamayunov ◽  
M.S. Dragomirov ◽  
...  
Keyword(s):  
High Performance ◽  
Cooling System ◽  
Chemical Elements ◽  
Dissimilar Materials ◽  
Physicochemical Characteristics ◽  
Operating Conditions ◽  
Solid Particles ◽  
Physicochemical Interaction ◽  
Cooling Systems ◽  
Thin Oxide Film

The article describes the results of a study of the physicochemical characteristics of solid particles of contaminants present in the coolant of automobile and tractor engines. The data on the fractional, physical and chemical composition of solid particles of contamination are given. It was established that the generalized reason for the appearance of contaminants of various nature in liquid cooling systems of engines is the physicochemical interaction of the coolant (antifreeze) with different elements and dissimilar materials of the cooling system. The use of absolutely pure coolant in the cooling systems of automobile and tractor engines is practically unrealistic, since there will always be operating conditions that contribute to the formation of contamination. A number of chemical elements (in an amount from 1 to 47% of each element) were found in the composition of solid particles of coolant contaminants: iron Fe, silicon Si, aluminum Al, lead Pb, tin Sn, zinc Zn, calcium Ca, magnesium Mg, copper Cu. In addition, at a level of less than 1.0% (wt.), Such chemical elements as potassium K, sodium Na, titanium Ti, phosphorus P, sulfur S, chromium Cr, molyb-denum Mo, chlorine Cl, iridium Ir, nickel Ni, manganese Mn, etc. were found. The most dangerous contaminants are particles of iron Fe and silicon Si, contained in the coolant in an amount of up to 47 and 37%, respectively, and possessing significant hardness and angularity. The abrasive proper-ties of Fe and Si particles create the danger of removing a thin oxide film on the inner surface of the walls of the cooling radiator channels, leading to their premature destruction. In this regard, it is concluded that high-performance engine coolant filters should be used in automobiles and tractors to remove these contaminants from the flow.

Performance Analysis With Future Predictions of Different Solar Cooling Systems in Guayaquil, Ecuador

2014 ◽  
Author(s):  
Carlos Naranjo-Mendoza ◽  
Jesús López-Villada ◽  
Gabriel Gaona ◽  
Jerko Labus
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Meteorological Data ◽  
Cooling Systems ◽  
Great Opportunity ◽  
Constant Flow Rate ◽  
Solar Cooling ◽  
Average Annual Temperature ◽  
System Configurations

This paper presents a comparative analysis of three different solar cooling system configurations developed for a case study building in Guayaquil, Ecuador. Guayaquil is a city located at the Ecuadorian coast with an average annual temperature of 25°C. The city’s need for air conditioning throughout the year and the relatively intense solar radiation provide a great opportunity for implementation of solar cooling systems. The first cooling system includes a 175 kWc single-effect absorption chiller powered by evacuated tubes solar thermal collectors. This system was compared with two 140 kWc compression chiller systems (air-cooled (AC) and water-cooled (WC)) powered by grid-connected photovoltaics. Both constant flow rate (CFR) and variable flow rate (VFR) of chilled water were analyzed. The three systems have to satisfy a cooling demand of the top floor in one governmental building (app. 1296 m2) which was selected as case study. Additionally, two 140 kWc conventional compression chiller systems (AC and WC) were included in the comparison as reference systems. Cooling demand of the building was simulated in EnergyPlus and coupled with the appropriate system configurations developed in TRNSYS. The weather file (TMY) was developed based on real meteorological data collected in the last decade. The present analysis was extended with the prediction scenarios for the years 2020, 2050 and 2080 using climate change adapted weather files.

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).

scholarly journals Cost and Performance Goals for Commercial Active Solar Absorption Cooling Systems

1985 ◽  
Vol 107 (2) ◽  
pp. 136-140 ◽  
Author(s):  
M. L. Warren ◽  
M. Wahlig
Keyword(s):  
Performance Analysis ◽  
Solar System ◽  
Thermal Performance ◽  
Return On Investment ◽  
Simulation Analysis ◽  
Cooling System ◽  
Cooling Systems ◽  
System Cost ◽  
Solar Cooling ◽  
Absorption Cooling

Economic and thermal performance analysis is used to determine cost goals for typical commercial active solar cooling systems to be installed between the years 1986 and 2000. Market penetration for heating, ventilating, and air conditioning systems depends on payback period, which is related to the expected return on investment. Postulating a market share for solar cooling systems increasing to 20 percent by the year 2000, payback and return on investment goals as a function of year of purchase are established. The incremental solar system cost goals must be equal to or less than the 20-year percent value of future energy savings, based on thermal performance analysis, at the desired return on investment. The methodology is applied to determine the allowable incremental solar system cost for commercial-scale, 25-ton absorption cooling systems based on the thermal performance predicted by recent simulation analysis, Methods for achieving these cost goals and expected solar cooling system costs will be discussed.

scholarly journals Performance Assessment of Solar Cooling Systems with Energy Storage

2021 ◽  
Vol 312 ◽  
pp. 08014
Author(s):  
Giovanni Brumana ◽  
Giuseppe Franchini ◽  
Elisa Ghirardi
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Optimal Size ◽  
Ambient Conditions ◽  
Absorption Chiller ◽  
Cooling Systems ◽  
Detailed Model ◽  
Adsorption Chiller ◽  
Solar Cooling ◽  
Evaporative Cooling System

The paper presents a complete solar cooling comparison. A detailed model of a tertiary sector building has been evaluated in three locations (Riyadh, Abu Dhabi, and Palermo) and coupled with four solar cooling systems: two solar thermal cooling systems (Li-Br absorption chiller and adsorption chiller), a solar Desiccant Evaporative Cooling system and a solar electric cooling (Photovoltaic coupled with Compression chiller). A multi-variable optimization procedure selects the optimal size of each component. The results show that the solar cooling system based on absorption chiller satisfied the cooling demand regardless of the site location whilst the performance of the Desiccant Evaporative Cooling system is dramatically affected by ambient conditions. The electric solar cooling option shows the best overall efficiency and appears a costeffective solution despite the high cost of the storage system.

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).

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