Journal Article•
Performance Characteristics of "Vapour Compression Refrigeration System" Under Real Transient Conditions
01 Jan 2011-International Journal of Advancements in Technology (Longdom Publishing SL)-Vol. 2011, Iss: 4, pp 584-593
TL;DR: In this article, the behavior of a simple vapour compression refrigeration system was studied while its working under transient conditions occurred during cooling of a fixed mass of brine from initial room temperature to sub-zero refrigeration temperature.
Abstract: The behavior of performance parameters of a simple vapour compression refrigeration system were studied while its working under transient conditions occurred during cooling of a fixed mass of brine from initial room temperature to sub-zero refrigeration temperature. The effects of different lengths of capillary tube over these characteristics have also been investigated. It was concluded that with the constantly falling temperature over evaporator, refilling of it with more and more liquid refrigerant causes multifold increase in heat transfer coefficient which helps in maintaining refrigeration rate at falling temperature. Larger capillary tube decreases the tendency of refilling of evaporator but offers less ‘evaporator temperature’ effective in lower range of refrigeration temperature. Shorter capillary tube ensures higher COP initially but which deteriorates at a faster rate in lower temperature range. Capillary tube length must be optimized for maximum overall average COP of the system for the complete specified cooling job.
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01 Jan 2016
TL;DR: The refrigeration and air conditioning is universally compatible with any devices to read and is available in the authors' digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you for downloading refrigeration and air conditioning. As you may know, people have look hundreds times for their favorite readings like this refrigeration and air conditioning, but end up in harmful downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some harmful bugs inside their computer. refrigeration and air conditioning is available in our digital library an online access to it is set as public so you can download it instantly. Our book servers spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the refrigeration and air conditioning is universally compatible with any devices to read.
295 citations
TL;DR: In this paper, the authors investigated the dynamic behavior of a split R-410A air conditioner comprising variable speed compressor, variable speed condenser fan, three speed evaporator fan and electronic expansion valve.
Abstract: Variable speed technology has a great potential for improving energy efficiency and performance of vapor compression refrigeration cycle. Therefore, the study of dynamic characteristics of the refrigeration cycle using this new technology becomes essential. This study experimentally investigates the dynamic behavior of a split R-410A air conditioner comprising variable speed compressor, variable speed condenser fan, three speed evaporator fan and electronic expansion valve. The characteristics of the conditioner have been presented during the startup and shutdown periods. Furthermore, the effect of changing evaporator fan speed during the running of the conditioner has been illustrated and discussed. The influence of evaporator and condenser inlet air temperatures on the power consumption and coefficient of performance of the conditioner has also been investigated. The experimental results show that increasing the condenser entering air temperature by 7 °C, the power consumption has been increased by 18% and the coefficient of performance decreased by 15%.
12 citations
TL;DR: In this paper, the effect of the configuration and the capillary tube diameter on the overall performance of a simple vapour compression refrigeration system was studied, and the experimental results revealed that the mass flow rate is maximum for the straight configuration and is least for the helical coiled configuration.
Abstract: The study of the expansion device in the simple vapour compression refrigeration system is necessary in order to understand the parameters which can enhance the overall performance of the system. The experimental study was done on the capillary tubes of 31 gauge, 36 gauge and 40 gauge and each test section was studied with three distinct configurations i.e. helical coiled, straight coiled and serpentine coiled configuration. The effect of the configuration and the capillary tube diameter on the overall performance of the system was studied. The findings of the experimental study revealed that the mass flow rate is maximum for the straight configuration and is least for the helical coiled configuration. The refrigeration effect was found to be maximum for the helical coiled configuration and was found to be least for straight coiled configuration. The compressor work was found to reduce as the load was increased on the system. Decreasing the capillary tube diameter increased the mass flow rate in the system and decreased the refrigeration effect produced.
9 citations
TL;DR: In this paper, a multiresponse optimization approach was employed to optimize the efficiency of a refrigeration cycle demonstration unit using a multi-response optimization approach to simultaneously minimize energy consumption and maximize the refrigeration effect.
Abstract: Response surface methodology was employed to optimize the efficiency of a refrigeration cycle demonstration unit using a multiresponse optimization approach. Statistically designed experiments were conducted to simultaneously minimize energy consumption and maximize the refrigeration effect of a compression refrigeration cycle. Regression models were fitted to refrigeration and electrical powers and optimal variable settings were identified using an easy-to-use optimization criterion. Results give confidence to apply the illustrated approach in academic and industrial settings, namely for optimizing equipment operation.
9 citations
TL;DR: In this paper, the design, calculation and dimensioning of a small powered refrigeration system (132W) which produces ice bars (freezing) using solar thermal power, and resorts to an intermittent cycle absorption circuit with a water-ammonia mixture (H2O-NH3).
Abstract: This article is dedicated to the design, calculation and dimensioning of a small powered refrigeration system (132W) which produces ice bars (freezing) using solar thermal power, and resorts to an intermittent cycle absorption circuit with a water-ammonia mixture (H2O-NH3). The aim of this equipment is to minimize problems faced in places where there is no electric network to supply traditional refrigeration systems which preserve perishable products produced or stocked there, as well as drugs (vaccines), namely for specific regions of developing countries. The system developed can be divided into two parts. The intermittent cycle absorption refrigeration system uses a binary water-ammonia solution (H2O-NH3), where water is the absorber and the ammonia is the coolant and the thermal solar system. This is made up of CPC flat plate thermal collectors or vacuum tubes in which solar energy heats the water that circulates in the primary circuit. In the absorption circulation system, circulation occurs in a natural way due to the fluids affinity, and the temperature and pressure internal variations. This article shows the assumptions underlying the conception, calculation and dimensioning of the system’s construction.
5 citations
References
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TL;DR: In this article, the efficiency of a Carnot engine for the case where the power output is limited by the rates of heat transfer to and from the working substance was analyzed, and it was shown that the efficiency at maximum power output was given by the expression η = 1 − (T2/T1)1/2 where T1 and T2 are the respective temperatures of the heat source and heat sink.
Abstract: The efficiency of a Carnot engine is treated for the case where the power output is limited by the rates of heat transfer to and from the working substance. It is shown that the efficiency, η, at maximum power output is given by the expression η = 1 − (T2/T1)1/2 where T1 and T2 are the respective temperatures of the heat source and heat sink. It is also shown that the efficiency of existing engines is well described by the above result.
1,965 citations
"Performance Characteristics of "Vap..." refers background in this paper
...The performance of a simple vapour compression refrigeration system, used in numerous of small refrigeration applications all over the world, deteriorates in actual conditions due to internal and external irreversibility [1, 2, 3, 4] and further due to transient conditions over evaporator and condenser....
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Book•
01 Jan 1958
TL;DR: In this paper, the authors present an equipment-oriented textbook that applies theoretical results of engineering theories to refrigeration and air conditioning engineering problems, which enables the student to understand both common and uncommon problems in designing, selecting and applying air conditioning and refrigeration components and systems.
Abstract: This is a thorough revision of the definitive, classic text for any level course on refrigeration, refrigeration and air conditioning, and environmental control in buildings. It is an equipment-oriented textbook that applies theoretical results of engineering theories to refrigeration and air conditioning engineering problems. This enables the student to understand both common and uncommon problems in designing, selecting and applying air conditioning and refrigeration components and systems. The material has been updated to apply to the new Environmental Protection Agency requirements and to the new technology developed in response to the energy crisis. New to this edition is a discussion of solar energy; coverage of the basic principles of acoustics and noise control (in relation to air conditioning systems), fans and ducts, pumps and piping, and air conditioning units. While all the material in the text can be understood and executed without computers, alternate computer solutions are shown for system simulation. SI units are used throughout.
763 citations
TL;DR: In this article, the authors reviewed the state-of-the-art of finite time thermodynamic theory and applications from the point of view of both physics and engineering, focusing on the performance optimization of thermodynamic processes and devices with finite-time and/or finite-size constraints.
Abstract: Abstract The historical background, research development, and the state-of-the-art of finite time thermodynamic theory and applications are reviewed from the point of view of both physics and engineering. The emphasis is on the performance optimization of thermodynamic processes and devices with finite-time and/or finite-size constraints, including heat engines, refrigerators, heat pumps, chemical reactions and some other processes, with respect to the following aspects: the study of Newton's law systems, an analysis of the effect of heat resistance and other irreversible loss models on the performance, an analysis of the effect of heat reservoir models on the performance, as well as the application for real thermodynamic processes and devices. It is pointed out that the generalized thermodynamic optimization theory is the development direction of finite thermodynamics in the future.
716 citations
"Performance Characteristics of "Vap..." refers background in this paper
...[6] More is the temperature difference between external fluid and refrigerant across evaporator and condenser, better would be heat transfer in evaporator and condenser and...
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01 Jan 2016
TL;DR: The refrigeration and air conditioning is universally compatible with any devices to read and is available in the authors' digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you for downloading refrigeration and air conditioning. As you may know, people have look hundreds times for their favorite readings like this refrigeration and air conditioning, but end up in harmful downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some harmful bugs inside their computer. refrigeration and air conditioning is available in our digital library an online access to it is set as public so you can download it instantly. Our book servers spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the refrigeration and air conditioning is universally compatible with any devices to read.
295 citations
"Performance Characteristics of "Vap..." refers background or methods in this paper
...[12, 13] Other performance parameters of the system are also calculated for each time point as per the procedure given below:...
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...[12] The length of capillary tube may be...
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