Modelling of phase change for Two-Phase Refrigerant Flow inside Capillary Tube under Adiabatic Conditions (original) (raw)
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IJERT-Simulation of Flow Characteristics of Refrigerant inside Adiabatic Straight Capillary Tube
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/simulation-of-flow-characteristics-of-refrigerant-inside-adiabatic-straight-capillary-tube https://www.ijert.org/research/simulation-of-flow-characteristics-of-refrigerant-inside-adiabatic-straight-capillary-tube-IJERTV2IS90720.pdf In the present investigation, an attempt is made to develop mathematical model to determine the flow characteristics of refrigerant inside a straight capillary tube for adiabatic flow conditions. The proposed model can predict the length of the adiabatic straight capillary tube for a given mass flow rate. In the present study R-12 has been used as a working fluid inside the straight capillary tube of diameter 1.17 mm and 1.41 mm and used the same model to study the flow characteristics of refrigerant in ANSYS CFX software. Finally the results of mathematical model are valuated with ANSYS CFX and the results are found to be in fair agreement.
Improved refrigerant characteristics flow predictions in adiabatic capillary tube
Research Journal of Applied Sciences, Engineering and Technology, 2012
This study presents improved refrigerant characteristics flow predictions using homogenous flow model in adiabatic capillary tube, used in small vapor compression refrigeration system. The model is based on fundamental equations of mass, momentum and energy. In order to improve the flow predictions, the inception of vaporization in the capillary tube is determined by evaluating initial vapor quality using enthalpy equation of refrigerant at saturation point and the inlet entrance effect of the capillary tube is also accounted for. Comparing this model with experimental data from open literature showed a reasonable agreement. Further comparison of this new model with earlier model of Bansal showed that the present model could be use to improve the performance predictions of refrigerant flow in adiabatic capillary tube.
NUMERICAL INVESTIGATION OF CAPILLARY TUBE BY REPLACING THE INSIDE REFRIGERANT AND DIAMETER
The capillary tube used in the mostly in the refrigerant flow control devices. Hence performance of the capillary tube is best for good refrigerant flow. The many researchers had been concluding performance using experimentally, theoretically and analysis based. In this present work analyze the flow analysis of the refrigerant inside a capillary tube for adiabatic flow conditions. The proposed model can predict flow characteristics in adiabatic capillary tubes for a given mass flow rate. In the present work R-22 is replaced by Ammonia refrigerant has been used as a working fluid inside the capillary tube and the capillary tube design is changed straight to coiled capillary, which taken from good literature. The analysis is done in ANSYS CFX 16.2 software. It is observed from the results dryness fraction by using the helical capillary tube (Ammonia refrigerant flow) is better than straight and existing helical capillary tube (R22 refrigerant flow). The best suitable helical coiled design is suggested.
IJERT-CFD Flow Analysis of a Refrigerant inside Adiabatic Capillary Tube
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/cfd-flow-analysis-of-a-refrigerant-inside-adiabatic-capillary-tube https://www.ijert.org/research/cfd-flow-analysis-of-a-refrigerant-inside-adiabatic-capillary-tube-IJERTV2IS90289.pdf Capillary tubes are widely used as a refrigerant flow control device in small refrigeration systems. Since the flow behaviour inside the capillary tube is complex, many physical models are necessary to predict the characteristics of the refrigerant flow in a capillary tube. The refrigerant leaves the compressor at high pressure and temperature and enters the condenser. After leaving the condenser the refrigerant is at medium temperature and high pressure and then it enters the Capillary tube. In the Capillary tubes the pressure and the temperature of the refrigerant is reduced drastically and suddenly. Thus us it is the throttling valve where the temperature of the refrigerant is reduced and it is then able to produce the cooling effect in the evaporator of the refrigerator or the cooling coil of the air conditioner. In the present investigation, an attempt is made to analyze the flow Analysis of the refrigerant inside a straight capillary tube and coiled capillary tube for adiabatic flow conditions. The proposed model can predict flow characteristics in adiabatic capillary tubes for a given mass flow rate. In the present study R-22 has been used as a working fluid inside the straight capillary tube and coiled capillary tube of diameter 1.27 mm and used the same model to study the flow characteristics of refrigerant in ANSYS CFX software. It is observed from the results dryness fraction by using the helical capillary tube is better than straight capillary tube. The best suitable helical coiled design is suggested.
The capillary tube used mostly in the refrigerant flow control devices. Hence performance of the capillary tube should be good for smooth refrigerant flow. Many researchers worked in these area by experimentally and analytically. In this present work analyse the flow analysis of the refrigerant inside a capillary tube for adiabatic flow conditions. The proposed model has predict flow characteristics in adiabatic capillary tubes for a given mass flow rate. In the current work R-22 is replaced by Ammonia refrigerant has been used as a working fluid inside the capillary tube and the capillary tube design is changed straight to coiled capillary, which taken from good literature. The analysis is done in ANSYS CFX 16.2 software. It is observed from the results dryness fraction by using the helical capillary tube (Ammonia refrigerant flow) is better than straight and existing helical capillary tube (R22 refrigerant flow). The best suitable helical coiled design is suggested.
CFD Parametric Investigation for Two Phase Flow of Refrigerant 134 a In an Adiabatic Capillary tube
2016
Capillary tubes are widely used as refrigerant flow control device in a small refrigeration systems. Since the flow behavior inside a capillary tube is complex, several physical models are necessary to predict the characteristics of refrigerant flow in the capillary tube. A refrigerant leaves the compressor at high pressure & temperature and enters the condenser. After leaving the condenser the refrigerant is at medium temperature & high pressure and then it enters the Capillary tube. In a Capillary tubes the pressure and the temperature of a refrigerant is reduced drastically and suddenly. Thus us it is a throttling valve where the temperature of the refrigerant is reduced and it is then able to produce the cooling effect in evaporator of the refrigerator or cooling coil of the air conditioner. In the present investigation, an attempt is made to analyze the two phase flow of the refrigerant 134a inside a helical capillary tube for adiabatic flow conditions. First of all a validatio...
A Review report on “CFD analysis of Fluid Flow in a capillary tube using various refrigerant”
In the past several years a number of new alternative refrigerant have been discovered to replace the existing refrigerants used in refrigerating equipment for improvement of performance. In order to study these refrigerants extensively an in-depth knowledge of their single-phase heat transfer characteristics, thermodynamic properties as well as simulation analysis is needed. This paper provides a literature review of current research that has been conducted on single phase flow for alternative refrigerants, addresses a number of relations for determining the thermodynamic properties of these alternative refrigerants with computational fluid analysis using different software likewise ANSYS ; and discusses their sensitivity to uncertainty. Finally, an overview of some of the current research that has been conducted on various enhancements and refrigerant / oil mixtures is provided as well. Present paper give a brief study about throttling expansion of refrigerant, capillary tube, refrigerant property and mathematical correlation for the flow through the capillary tubes of different geometries operating under adiabatic and diabetic flow conditions. Keywords: CFD; Fluid Flow; ANSYS; Refrigeration.