scholarly journals ِA simulation of effect the change in capillary tube diameter on a compression refrigeration system performance

2012 ◽  
Vol 7 (1) ◽  
pp. 1-21
Author(s):  
Tamir K. Salim ◽  
Samer M. Khalaf ◽  
Saad S. Farhan
Keyword(s):  
System Performance ◽  
Capillary Tube ◽  
Tube Diameter ◽  
Refrigeration System

The heat exchangers tubes mineral type effect on the refrigeration system performance using different lengths of the capillary tube

2021 ◽  
pp. 095440622110022
Author(s):  
Thamer Khalif Salem ◽  
Saad Sami Farhan ◽  
Raaid Rashad Jassem Al Doury ◽  
Israa Sami Farhan
Keyword(s):  
Heat Exchangers ◽  
System Performance ◽  
Capillary Tube ◽  
Experimental Results ◽  
Tube Length ◽  
Working Fluid ◽  
Internal Diameter ◽  
Refrigeration System ◽  
Transfer Unit ◽  
Mineral Type

An experimental study is conducted to show the influence of the tubes material type of the heat exchanger on the refrigeration system performance. The system is operated by using R134a as a working fluid, 2 mm internal diameter, and different lengths of capillary tubes which were 120, 135, and 150 cm. The experimental results showed that when increasing the refrigerant mass flowrates led to reducing each of the performance coefficient COP, number of transfer unit NTU and evaporator effectiveness ε. However, the highest improvement had appeared for each parameter COP, NTU, and ε which were 21%, 113.38%, and 59.42% respectively at a capillary tube length of 120 cm and [Formula: see text] = 3.19 g/s compared to the length of capillary tube 150 cm. Besides, it was found an increase in [Formula: see text] with the incrementing in the capillary tube length from 120 cm to 150 cm. The biggest percentage of compression power was 23% at the capillary tube length of 150 cm compared to others at [Formula: see text] = 3.71 g/s. Finally, the experimental results of COP and [Formula: see text] were validated by comparing them with other publications.

Design and Build of Teaching and Experimental Marine Cold Store

2014 ◽  
Vol 556-562 ◽  
pp. 907-911
Author(s):  
Chang Wei He ◽  
Meng Zhang ◽  
Xiao Ping Jia ◽  
Yuan Liu
Keyword(s):  
Thermal Performance ◽  
System Performance ◽  
Heat Load ◽  
Refrigeration System ◽  
Electrical System ◽  
Technology Application ◽  
Design Scheme ◽  
Expansion Valve ◽  
Cold Store ◽  
Practical Teaching

In the paper, the design scheme of the new cold store is proposed firstly, with the consideration of the latest technology application and the convenience and maneuverability of practical teaching. Then the refrigeration system is designed based on the calculation of the heat load of the cold store. The suited components such as compressor, evaporator, condenser and expansion valve are selected and the electrical system is designed. After that the whole unit is installed and adjusted to make sure that the installation is propitious to improve the system performance and convenient for training. Finally the thermal performance of the new cold store system is tested and compared with the old system test. The result shows that the matching of the new refrigeration system is reasonable and the new cold store is up to the mustard. With the help of training on the cold store, the students will meet the essential requirements of STCW 78/95 convention on application and management of the marine cold store.

scholarly journals Cop Enhancement of Vapour Compression Refrigeration System

2021 ◽  
pp. 1-6
Author(s):  
B Sairamakrishna ◽  
◽  
T Gopala Rao ◽  
N Rama Krishna ◽  
◽  
...  
Keyword(s):  
Tube Diameter ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Expansion Valve ◽  
Compressor Inlet ◽  
Work Input ◽  
Compressor Work ◽  
Vapour Compression ◽  
Design And Testing ◽  
Nozzle Inlet

This experimental investigation exemplifies the design and testing of diffuser at compressor inlet and nozzle at condenser outlet in vapour compression refrigeration system with the help of R134a refrigerant. The diffuser with divergence angle of 12°,14° and the nozzle with convergent angle 12°,14° are designed for same inlet and outlet diameters. Initially diffusers are tested at compressor inlet diffuser is used with inlet diameter equal to exit tube diameter of evaporator and outlet tube diameter is equal to suction tube diameter of the compressor. Diffuser helps to increases the pressure of the refrigerant before entering the compressor it will be helps to reduces the compression work and achieve higher performance of the vapour compression refrigeration system. Then nozzles are testing at condenser outlet, whereas nozzle inlet diameter equal to discharging tube diameter of condenser and outlet diameter equal to inlet diameter of expansion valve. Additional pressure drop in the nozzle helped to achieve higher performance of the vapour compression refrigeration system. The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance (COP).

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

2014 ◽  
Vol 11 (3) ◽  
pp. 05-07
Author(s):  
Shashank shekhar pathak ◽  
◽  
Prakhar shukla ◽  
Sanjeev chauhan
Keyword(s):  
Capillary Tube ◽  
Refrigeration System ◽  
Vapour Compression

The Performance of Air-Air Ejectors With Triangular Tabbed Driving Nozzles

2006 ◽  
Author(s):  
S. F. McBean ◽  
A. M. Birk
Keyword(s):  
Experimental Investigation ◽  
System Performance ◽  
Experimental Testing ◽  
Back Pressure ◽  
Tube Diameter ◽  
Performance Parameters ◽  
Mixing Performance ◽  
Performance Improvements ◽  
Significant Performance ◽  
Ejector System

This paper describes an experimental investigation into the effects of geometrical variations on ejector system performance when the driving nozzle includes delta mixing tabs. Mixing tabs have been shown to provide good mixing performance with comparable back-pressure penalties to other types of enhanced mixing nozzles. The performance parameters of most interest are pumping, mixing, and back-pressure. Geometric parameters studied include standoff distance, mixing-tube diameter, and tab angle. Experimental testing showed significant performance improvements in mixing and pumping with a decrease in tab angle. Maximum mixing was found to occur with tab angles positioned at 120°. Exceptional mixing was also observed with increased standoff. Back-pressure was shown to increase with increasing standoff and decreasing tab angle, but was not affected by mixing-tube diameter. In addition, a zone of recirculation was identified at the entrance to the mixing-tube. This zone is thought to have an influence on ejector performance.

Miniature Vapor Compression Refrigeration Systems for Active Cooling of High Performance Computers

2001 ◽  
Author(s):  
Ali Heydari ◽  
Kathy Russell
Keyword(s):  
Heat Exchanger ◽  
High Performance ◽  
Capillary Tube ◽  
New Technology ◽  
Mathematical Formulation ◽  
Coefficient Of Performance ◽  
Simulation Program ◽  
Vapor Compression ◽  
Refrigeration System ◽  
System Components

Abstract A small refrigeration system for cooling of computer system components is evaluated. A thermodynamic model describing the performance of the cycle along with a computer simulation program is developed to evaluate its performance. The refrigeration system makes use of a miniature reciprocating vapor compression compressor. Due to space limitations in some high performance computer servers, a miniature refrigeration system composed of a compressor, capillary tube, a compact condenser, and a cold-plate evaporator heat exchanger are used. Mathematical multi-zone formulation for modeling thermal-hydraulic performance of heat exchanger for the condenser and evaporator are presented. The throttling device is a capillary tube and there is presented a mathematical formulation for predicting refrigerant mass flow rate through the throttling device. A physically based efficiency formulation for simulating the performance of the miniature compressor is used. An efficient iterative numerical scheme with allowance for utilization of various refrigerants is developed to solve the governing system of equations. Using the simulation program, the effects of parameters such as the choice of working refrigerant, evaporating and condensing temperatures on system components and overall efficiency of system are studied. In addition, a RAS (reliability, availability and serviceability) discussion of the proposed CPU-cooling refrigeration solution is presented. The results of analysis show that the new technology not only overcomes many shortcomings of the traditional fan-cooled systems, but also has the capacity of increasing the cooling system’s coefficient of performance.

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