Effect of Coiled Capillary Tube Pitch on Vapor Compression Refrigeration System Performance.

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Effect of Coiled Capillary Tube Pitch on Vapor Compression Refrigeration System Performance.

Effect of Coiled Capillary Tube Pitch on Vapor Compression Refrigeration System Performance.

01 Jan 2008-

TL;DR: In this paper, the authors examined the effects of pitches of both helical and serpentine coiled capillary tubes on the performance of a vapor compression refrigeration system and found that both pitch and height affects the system performance.

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Abstract: The effects of various geometries of capillary tubes has been investigated by many researchers. Their studies were based on the coil diameters and lengths alone, with no particular attention placed on the effect of coil pitch. At present no information is available about the effects of serpentine coiled capillary tubes on refrigerator performance. This study examined the effects of pitches of both helical and serpentine coiled capillary tubes on the performance of a vapor compression refrigeration system. Several capillary tubes of equal lengths (2.03 m) and varying pitches, coiled diameters, and serpentine heights were used. Both inlet and outlet pressure and temperature of the test section (capillary tube) were measured and used to estimate the coefficient of performance (COP) of the system. The results show that, in the case of helical coiled geometries the pitch has no significant effect on the system performance but the coil diameter as already predicted by many researchers. In the case of serpentine geometries both pitch and height affects the system performance. Performance increases with both increase in the pitch and the height. Correlations were proposed to describe relationships between straight and coiled capillary tube and between helical coiled and serpentine coiled capillary tubes. The coefficient of correlations are: 0.9841 for mass flow rates of helical and serpentine with straight tubes; 0.9864 for corresponding COPs and 0.9996 for mass flow rates of serpentine and helical coiled tube.

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Refrigeration And Air Conditioning

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Barbara Pfeffer

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.

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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.

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295 citations

Journal Article•DOI•

An experimental study of the Effect of capillary tube diameter and configuration on the performance of a simple vapour compression refrigeration system

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Shashank shekhar pathak, Prakhar shukla, S.S. Chauhan, Aparajita Srivastava

01 Jan 2014-IOSR Journal of Mechanical and Civil Engineering

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.

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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.

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9 citations

Cites background from "Effect of Coiled Capillary Tube Pit..."

...M.Y.Taib [2] et al. (2010) studied the performance of a domestic refrigerator and developed a test rig from refrigerator model NRB33TA....
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Journal Article•DOI•

Validation of a vapour compression refrigeration system design model

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M. A. Akintunde

01 Aug 2011-American Journal of Scientific and Industrial Research

TL;DR: In this paper, the authors presented the validation of a design model for vapour compression refrigeration systems developed by Akintunde (2004a), which was used to design a vapour compressed refrigeration system.

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Abstract: This paper presents the validation of a design model for vapour compression refrigeration systems developed by Akintunde (2004a). This model was used to design a vapour compression refrigeration system. The experimental set-up is made up of: a compressorreciprocating type, 0.746 kW capacity, using R134a as working fluid, with cylinder stoke volume of 32.7 cm; evaporator and condenser, bare coil tube-in-tube serpentine copper coil. The cycle performance was evaluated through the following parameters; Cooling load (Qe); Condensing load (Qc); Coefficient of performance (COP) and mass flow rate. The R values (calculating using excel) of the COPs under subcooling and superheating with the degree of subcooling and superheating conditions were 80.7% and 88% respectively. While the correlations between the COPs under the same conditions were 88% and 99.9%. The present analysis showed that the model results are comparable to the actual system from both quantitative and qualitative points of view. Under the same operational conditions, maximum absolute deviations of the variable parameters – mass flow rate, COP and circulating water temperature, are within the range of 16%.

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8 citations

Cites background from "Effect of Coiled Capillary Tube Pit..."

...There are many other works published on the alternatives to R-12 and other ozone depletion refrigerants, some of these are: Kutter (1988); Clark, (1999); Eckels and Tesene (2003); Eckels and Tesene (2004); Sand et al., (1990); Crow et al....
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...There are many other works published on the alternatives to R-12 and other ozone depletion refrigerants, some of these are: Kutter (1988); Clark, (1999); Eckels and Tesene (2003); Eckels and Tesene (2004); Sand et al....
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...There are many other works published on the alternatives to R-12 and other ozone depletion refrigerants, some of these are: Kutter (1988); Clark, (1999); Eckels and Tesene (2003); Eckels and Tesene (2004); Sand et al., (1990); Crow et al., (1992). It has been concluded by many researchers that – from thermodynamic point of view R-134a is closely related to R-12 in most important thermodynamic properties of refrigerants (Bolaji, 2008; Akintunde, 2007; Calm, 2002; Kim et al....
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...It has been concluded by many researchers that – from thermodynamic point of view R-134a is closely related to R-12 in most important thermodynamic properties of refrigerants (Bolaji, 2008; Akintunde, 2007; Calm, 2002; Kim et al., 2002)....
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...It has been concluded by many researchers that – from thermodynamic point of view R-134a is closely related to R-12 in most important thermodynamic properties of refrigerants (Bolaji, 2008; Akintunde, 2007; Calm, 2002; Kim et al., 2002)....
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An Experimental Investigation and Performance Evaluation of 1.5 TR Window Air-Conditioner by Using R22, R407C and R410A by Varying the Capillary Pitch

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K. John Samuel, K. Govindarajulu, G. Edison

01 Jan 2014

TL;DR: In this paper, the performance analysis of an window air conditioning system by using three refrigerants like R-22, R407C and R410A with different capillary pitches is addressed.

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Abstract: Due to ecological problems like Ozone depletion and Global warming certain refrigerants like R-22 have to be replaced. HCFC's (Hydro Chloro fluoro carbon) have been identified as the prime foremost cause of Ozone depletion. Driven by 1992 amendment to the Montreal-Protocol that calls for the phase out of HCFC's. HFC's (Hydro fluoro carbon) are substantially less damaging to the Ozone layer than HCFC's. Several refrigerants have emerged as substitutes to replace R-22, the most widely used Fluoro carbon refrigerant in the world. These include the environmentally friendly hydro carbon refrigerants such as R134a, R410A, R407A and R407C. In this present work problem of R-22 phase out in air conditioning application is addressed. The main objective of the project is Performance analysis of an window air conditioning system by using three refrigerants like R-22, R407C and R410A with different capillary pitches. In view of this it is proposed to carry out a number of experiments on window air conditioner of capacity 1.5 TR using R22, R407C and R410A by varying the capillary pitch. Further it is proposed to make a detailed analysis and comparison of the performance of these refrigerants at various pitches for an window air conditioner. From the results it is evident that the refrigerant with R410A with a capillary pitch of 18mm gave the best Coefficient of performance to retrofit an window air conditioner working on R22.

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5 citations

Cites methods from "Effect of Coiled Capillary Tube Pit..."

...But the present paper sucked through the valve V and it is discharged in to experimented different serpentine capillary pitches to atmosphere through the valve V after compressing it in know the performance parameters [5]....
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Journal Article•DOI•

Effect of capillary tube on the performance of a simple vapour compression refrigeration system

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Shashank shekhar pathak, Prakhar shukla, S.S. Chauhan

01 Jan 2014-IOSR Journal of Mechanical and Civil Engineering

TL;DR: In this article, the effect of capillary tube geometry on the performance of refrigeration systems was studied using both physical models and mathematical modeling concepts, and the parameters stated above can be further optimized in order to enhance the performance.

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Abstract: It is essential to study the effect of capillary tube geometry on the performance of refrigeration systems. The literature review focuses on the effect that geometrical parameters like capillary tube length, bore diameter, coil pitch, number of twist and twisted angle have on the pressure drop, coefficient of performance (COP) and mass flow rate of the system. These parameters can be further studied using physical models and mathematical modeling concepts. The parameters stated above can be further optimized in order to enhance the performance of the refrigeration system.

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5 citations

References

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Book•

Refrigeration and air conditioning

[...]

Wilbert F. Stoecker, Jerold W. Jones

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.

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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.

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763 citations

Refrigeration And Air Conditioning

[...]

Barbara Pfeffer

01 Jan 2016

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295 citations

"Effect of Coiled Capillary Tube Pit..." refers background in this paper

...This is a simple tube of a few millimeters internal diameter, usually ranging between 0.5 to 2 mm (Stoecker and Jones 1982)....
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Journal Article•DOI•

Evaluation of suction-line/liquid-line heat exchange in the refrigeration cycle

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Piotr A. Domanski¹, David Didion¹, J. P. Doyle•Institutions (1)

National Institute of Standards and Technology¹

01 Jan 1994-International Journal of Refrigeration-revue Internationale Du Froid

TL;DR: In this paper, the authors present a theoretical evaluation of the performance effects resulting from the installation of a liquid-line/suction-line heat exchanger (LLSL-HX), and examine cycle parameters and thermodynamic properties that determine whether the installation results in improvement of COP and volumetric capacity.

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Abstract: The paper presents a theoretical evaluation of the performance effects resulting from the installation of a liquid-line/suction-line heat exchanger (LLSL-HX). It examines cycle parameters and refrigerant thermodynamic properties that determine whether the installation results in improvement of COP and volumetric capacity. The study shows that the benefit of application of the LLSL-HX depends on a combination of operating conditions and fluid properties — heat capacity, latent heat, and coefficient of thermal expansion — with heat capacity being the most influential property. Fluids that perform well in the basic cycle are marginally affected by the LLSL-HX, and the impact on the coefficient of performance and volumetric capacity may be either positive or negative. Fluids performing poorly in the basic cycle benefit the from LLSL-HX installation through increase of the coefficient of performance and volumetric capacity.

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164 citations

Journal Article•DOI•

Experimental investigation of the performance of R22, R407C and R410A in several capillary tubes for air-conditioners

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S.G Kim¹, Min Soo Kim¹, Sung Tack Ro¹•Institutions (1)

Seoul National University¹

01 Aug 2002-International Journal of Refrigeration-revue Internationale Du Froid

TL;DR: In this article, a dimensionless correlation based on Buckingham π theorem was developed to predict the mass flow rate through the capillary tubes for R22, R407C and R410A.

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Abstract: The objective of this study is to present test results and to develop a dimensionless correlation on the basis of the experimental data of adiabatic capillary tubes for R22 and its alternatives, R407C (R32/125/134a, 23/25/52 wt.%) and R410A (R32/125, 50/50 wt.%). Several capillary tubes with different length and inner diameter were selected as test sections. Mass flow rate through the capillary tube was measured for several condensing temperatures and various degrees of subcooling at the inlet of each capillary tube. Experimental conditions for the condensing temperatures were selected as 40, 45 and 50°C, and the degrees of subcooling were adjusted to 1.5, 5 and 10°C. Mass flow rates of R407C and R410A were compared with those of R22 for the same test conditions. The results for straight capillary tubes were also compared with those of coiled capillary tubes. A new correlation based on Buckingham π theorem to predict the mass flow rate through the capillary tubes was presented based on extensive experimental data for R22, R407C and R410A. Dimensionless parameters were chosen considering the effects of tube geometry, capillary tube inlet conditions, and refrigerant properties. Dimensionless correlation predicted experimental data within relative deviations ranging from −12% to +12% for every test condition for R22, R407C and R410A. The predictions by the developed correlation were in good agreement with the results in the open literature.

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129 citations

"Effect of Coiled Capillary Tube Pit..." refers background or result in this paper

...Although the device lacks active function (mechanical or electrical) to actively adjust to any sudden change in the load conditions, it is still in use as a result of its simplicity, low cost, and requirement of low compressor starting torque (Kim et al. 2002)....
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...Although the device lacks active function (mechanical or electrical) to actively adjust to any sudden change in the load conditions, it is still in use as a result of its simplicity, low cost and requirement of low compressor starting torque (Kim et al. 2002)....
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...The test results of the helical-coiled capillary tubes agreed well with the results of Wei et al. (2001) and Akintunde et al....
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...The measured flow rate (using straight capillary tube) in this investigation falls within the results of Jung et al. (1999), Kim et al. (2002), and Akintunde (2004a), this is a justification of the experimental procedure....
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...Some of these can be found in the works of Bittle et al. (1998), ASHRAE (1994), Akintunde (2004a) and Kim et al. (2002)....
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Journal Article•DOI•

Capillary tube selection for HCFC22 alternatives

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Dongsoo Jung¹, Chunkun Park¹, Byungjin Park¹•Institutions (1)

Inha University¹

01 Dec 1999-International Journal of Refrigeration-revue Internationale Du Froid

TL;DR: In this article, pressure drop through a capillary tube is modeled in an attempt to predict the size of capillary tubes used in residential air conditioners and also to provide simple correlating equations for practicing engineers.

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Abstract: In this paper, pressure drop through a capillary tube is modeled in an attempt to predict the size of capillary tubes used in residential air conditioners and also to provide simple correlating equations for practicing engineers. Stoecker's basic model was modified with the consideration of various effects due to subcooling, area contraction, different equations for viscosity and friction factor, and finally mixture effect. McAdams' equation for the two-phase viscosity and Stoecker's equation for the friction factor yielded the best results among various equations. With these equations, the modified model yielded the performance data that are comparable to those in the ASHRAE handbook. After the model was validated with experimental data for CFC12, HFC134a, HCFC22, and R407C, performance data were generated for HCFC22 and its alternatives, HFC134a, R407C, and R410A under the following conditions: condensing temperature; 40, 45, 50, 55°C, subcooling; 0, 2.5, 5°C, capillary tube diameter; 1.2–2.4 mm, mass flow rate; 5–50 g/s. These data showed that the capillary tube length varies uniformly with the changes in condensing temperature and subcooling. Finally, a regression analysis was performed to determine the dependence of mass flow rate on the length and diameter of a capillary tube, condensing temperature, and subcooling. Thus determined simple practical equations yielded a mean deviation of 2.4% for 1488 data obtained for two pure and two mixed refrigerants examined in this study.

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83 citations

"Effect of Coiled Capillary Tube Pit..." refers methods or result in this paper

...According to Lee et al. (2002), Motta et al. (2002), and Akintunde (2004b) from system start-up, 120 minutes were typically required for the capacity used in this investigation to establish steady-state condition and approximately 90 minutes elapsed between each measured point (operating condition)....
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...The measured flow rate (using straight capillary tube) in this investigation falls within the results of Jung et al. (1999), Kim et al. (2002), and Akintunde (2004a), this is a justification of the experimental procedure....
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...These instruments were tested using a straight capillary tube of length 2.03 m, as predicted by Jung et al. (1999), Akintunde (2004b) and Akintunde et al. (2006) for a vapor compression refrigeration system of 10 kW capacity, operating under the conditions of 40oC condensing temperature, 1.62 mm…...
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