CO2 Trans-Critical Two Stage Compression Refrigeration Cycle with Vortex Tube

2011 ◽  
Vol 52-54 ◽  
pp. 255-260 ◽  
Author(s):  
Ying Bai Xie ◽  
Kui Kui Cui ◽  
Zhi Chao Wang ◽  
Jian Lin Liu
Keyword(s):  
Mass Fraction ◽  
Vortex Tube ◽  
Refrigeration Cycle ◽  
Two Stage ◽  
Fluid Mass ◽  
Cold Fluid ◽  
Exit Temperature ◽  
Discharge Pressure ◽  
Tube Expansion ◽  
Cold Gas

The paper analyses CO2 trans-critical two stage compression refrigeration cycle with vortex tube expansion by thermodynamics method. And compare with CO2 trans-critical two stage compression refrigeration cycle with expansion value. The results show that in the calculated conditions of the paper, the performance of the cycle with vortex tube improves 2.4%~16.3% than the cycle with expansion value. The optimal discharge pressure maximizing COP of the cycle with vortex tube exists. With lower evaporating temperature or higher gas cooler exit temperature, COP of system decreases and COP improvement increases. The effect of cold fluid mass fraction on COP is not significant, but COP improvement increases more quickly with cold gas mass fraction increasing.

Vortex Tube Expansion Two-Stage Transcritical CO2 Refrigeration Cycle

2012 ◽  
Vol 516-517 ◽  
pp. 1219-1223 ◽  
Author(s):  
Ying Fu Liu ◽  
Guang Ya Jin
Keyword(s):  
Mass Fraction ◽  
Vortex Tube ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Outlet Temperature ◽  
Two Stage ◽  
Evaporation Temperature ◽  
Optimum Heat ◽  
Tube Expansion ◽  
Cold Mass

Use of vortex tube as an expansion device in transcritical CO2 cycle could reduce the throttle loss and improve the coefficient of performance. In this paper, a vortex tube expansion two-stage transcritical CO2 refrigeration cycle(VTTC) is established and compared to that of the two-stage transcritical CO2 refrigeration cycle with throttle valve(TVTC). Thermodynamic analysis results indicate that there is also an optimum heat rejection pressure for the vortex tube cycle, and the COP improvement is 2.4%~16.3% at given conditions. Decrease in evaporation temperature or increase in gas-cooler outlet temperature decrease the COP, but the COP improvement will increase. The effect of cold mass fraction on the COP is negligible, but the COP improvement will increase fast with the increase of cold mass fraction.

scholarly journals Energetic and exergetic studies of modified CO2 transcritical refrigeration cycles

2020 ◽  
Author(s):  
Omprakash S Patil ◽  
Shrikant A Shet ◽  
Manish Jadhao ◽  
Neeraj Agrawal
Keyword(s):  
Heat Exchanger ◽  
Vortex Tube ◽  
Internal Heat ◽  
Evaporator Temperature ◽  
Internal Heat Exchanger ◽  
Work Recovery ◽  
Exit Temperature ◽  
Exergetic Analysis ◽  
Discharge Pressure ◽  
Tube Expansion

Abstract Thermodynamic analysis including energetic and exergetic analysis is carried out employing Engineering Equation Solver for the five modified cycles: dual expansion cycle, internal heat exchanger cycle, work recovery cycle, work recovery with internal heat exchanger cycle and vortex tube expansion cycle. Contours are developed to study the effect of gas cooler temperatures and evaporator temperatures on the system performance and optimum gas cooler pressure. The modified cycle with work recovery turbine offers relatively higher COP and higher exergetic efficiency with lower compressor discharge pressure. The exergy loss in compressor, gas cooler, throttle valve and vortex tube (VT) are considerably higher than that in internal heat exchanger (IHX), evaporator and turbine. It is observed that COP of modified cycle with VT is slightly less than that with IHX, whereas the cycle with work recovery turbine brings the highest COP with the improvement of 25% at the gas cooler exit temperature of 305 K and evaporator temperature of 248 K.

scholarly journals Performance Analysis of Natural-Refrigerants-Based Vortex Tube Expansion Refrigeration Cycles

2013 ◽  
Vol 06 (2) ◽  
Keyword(s):  
Performance Improvement ◽  
Vortex Tube ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Design Parameters ◽  
Refrigeration Cycle ◽  
Expansion Valve ◽  
Tube Expansion ◽  
Vapour Compression ◽  
Cycle Temperature

The energetic analyses and comparison of three natural refrigerants, ammonia, propane and isobutane based vapour compression refrigeration cycles are presented in this article using a vortex tube as an expansion device. A simple thermodynamic model has been used for analyses of two vortex tube expansion refrigeration cycle layouts based on the Maurer model (1999) and the Keller model (1997). Effects of various operating and design parameters of the COP improvement using vortex tube instead of expansion valve are presented. Results show that the COP improvement over basic expansion cycle increases with increase in cycle temperature lift for both cycle layouts. The COP improvement of CYC1 can be realized for certain operating temperature combinations. Effects of design parameters on the performance improvement are negligible. Study shows that the COP improvement using vortex tube as an expansion device are dependent on the refrigerant varieties, operating conditions as well as cycle configurations. Using the vortex tube as an expansion device, isobutane yields a maximum COP improvement of 12.2% for CYC2 followed by propane (11.5% for CYC2), whereas ammonia yields negligible improvement for studies ranges.

scholarly journals Numerical study of a double inlet chamber counter flow vortex tube with insulation

2021 ◽  
Vol 850 (1) ◽  
pp. 012024
Author(s):  
Ravi Kant Singh ◽  
Achintya Kumar Pramanick ◽  
Subhas Chandra Rana
Keyword(s):  
Vortex Tube ◽  
Numerical Study ◽  
Working Fluid ◽  
Turbulent Model ◽  
Counter Flow ◽  
Fluent Software ◽  
Exit Temperature ◽  
Flow Vortex ◽  
Inlet Chamber ◽  
Double Chamber

Abstract The present study intends to improve the performance of the Ranque-Hilsch counter flow vortex tube, analysed using computational fluid dynamics. In the axisymmetric 3-D, steady-state, compressible, and turbulent flow vortex tube, the air has been used as the working fluid. The ANSYS17.1 FLUENT software has been used with the standard º-ε turbulent model for different mass fraction of cold fluid and inlet pressure in the numerical simulation and validated with the experimental results. It is observed from the study that as the inlet chambers number increases from 1 to 2, there is a decrease of 7.8 % in the cold exit temperature of the vortex tube. However, insulating the double chamber vortex tube leads to a further reduction of 4.2% in the cold exit temperature. Therefore, it indicates that the overall decline in the cold exit temperature from one chamber non-insulated vortex tube to double chamber insulated vortex tube is 9.6%. In terms of cold exit temperature, it can be concluded that using a double inlet chamber vortex tube with insulation yields the optimum results.

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