Experimental study on the effect of angles and positions of mixing vanes on CHF in a 2×2 rod bundle with working fluid R-134a

2005 ◽  
Vol 235 (16) ◽  
pp. 1749-1759 ◽  
Author(s):  
Byung Soo Shin ◽  
Soon Heung Chang
Keyword(s):  
Experimental Study ◽  
Working Fluid ◽  
Rod Bundle ◽  
R 134A

Experimental study of thermohydraulic characteristics and irreversibility analysis of novel axial corrugated tube with spring tape inserts

2020 ◽  
Vol 92 (3) ◽  
pp. 30901
Author(s):  
Suvanjan Bhattacharyya ◽  
Debraj Sarkar ◽  
Ulavathi Shettar Mahabaleshwar ◽  
Manoj K. Soni ◽  
M. Mohanraj
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Thermal Performance ◽  
Working Fluid ◽  
The Novel ◽  
Heat Exchanger Tube ◽  
Heat Transfer Augmentation ◽  
Corrugated Tube ◽  
The Impact ◽  
Exchanger Tube

The current study experimentally investigates the heat transfer augmentation on the novel axial corrugated heat exchanger tube in which the spring tape is introduced. Air (Pr = 0.707) is used as a working fluid. In order to augment the thermohydraulic performance, a corrugated tube with inserts is offered. The experimental study is further extended by varying the important parameters like spring ratio (y = 1.5, 2.0, 2.5) and Reynolds number (Re = 10 000–52 000). The angular pitch between the two neighboring corrugations and the angle of the corrugation is kept constant through the experiments at β = 1200 and α = 600 respectively, while two different corrugations heights (h) are analyzed. While increasing the corrugation height and decreasing the spring ratio, the impact of the swirling effect improves the thermal performance of the system. The maximum thermal performance is obtained when the corrugation height is h = 0.2 and spring ratio y = 1.5. Eventually, correlations for predicting friction factor (f) and Nusselt number (Nu) are developed.

Experimental Study of a 200 kW Partial Oxidation Gas Turbine (POGT) for Co-Production of Power and Hydrogen-Enriched Fuel Gas

2009 ◽  
Author(s):  
Joseph Rabovitser ◽  
Stan Wohadlo ◽  
John M. Pratapas ◽  
Serguei Nester ◽  
Mehmet Tartan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Partial Oxidation ◽  
Synthesis Gas ◽  
Combustion Products ◽  
Working Fluid ◽  
Fuel Gas ◽  
Lean Combustion ◽  
Start Up ◽  
Oxidation Reactor

Paper presents the results from development and successful testing of a 200 kW POGT prototype. There are two major design features that distinguish POGT from a conventional gas turbine: a POGT utilizes a partial oxidation reactor (POR) in place of a conventional combustor which leads to a much smaller compressor requirement versus comparably rated conventional gas turbine. From a thermodynamic perspective, the working fluid provided by the POR has higher specific heat than lean combustion products enabling the POGT expander to extract more energy per unit mass of fluid. The POGT exhaust is actually a secondary fuel gas that can be combusted in different bottoming cycles or used as synthesis gas for hydrogen or other chemicals production. Conversion steps for modifying a 200 kW radial turbine to POGT duty are described including: utilization of the existing (unmodified) expander; replacement of the combustor with a POR unit; introduction of steam for cooling of the internal turbine structure; and installation of a bypass air port for bleeding excess air from the compressor discharge because of 45% reduction in combustion air requirements. The engine controls that were re-configured for start-up and operation are reviewed including automation of POGT start-up and loading during light-off at lean condition, transition from lean to rich combustion during acceleration, speed control and stabilization under rich operation. Changes were implemented in microprocessor-based controllers. The fully-integrated POGT unit was installed and operated in a dedicated test cell at GTI equipped with extensive process instrumentation and data acquisition systems. Results from a parametric experimental study of POGT operation for co-production of power and H2-enriched synthesis gas are provided.

Experimental study of influence of internal heat exchanger in a chest freezer using r-513a as replacement of r-134a

2021 ◽  
pp. 117969
Author(s):  
V. Pérez-García ◽  
D. Méndez-Méndez ◽  
J.M. Belman-Flores ◽  
J.L. Rodríguez-Muñoz ◽  
J.J. Montes-Rodríguez ◽  
...  
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Internal Heat ◽  
Internal Heat Exchanger ◽  
R 134A

scholarly journals CFD Analysis of the Optimization of Length of Capillary Tube for a Vapor Compression Refrigeration System

2021 ◽  
Vol 9 (8) ◽  
pp. 2567-2578
Author(s):  
Ms. K. P. Bhangle
Keyword(s):  
Capillary Tube ◽  
Flow Analysis ◽  
Small Diameter ◽  
Flow Characteristics ◽  
Working Fluid ◽  
Vapor Compression ◽  
Adiabatic Flow ◽  
Ansys Cfx ◽  
Vapor Compression Refrigeration ◽  
R 134A

Abstract: The capillary tube is commonly employed in refrigerant flow control systems. As a result, the capillary tube's performance is optimal for good refrigerant flow. Many scholars concluded performance utilising experimental, theoretical, and analysis-based methods. This paper examines the flow analysis of a refrigerant within a capillary tube under adiabatic flow circumstances. For a given mass flow rate, the suggested model can predict flow characteristics in adiabatic capillary tubes. In the current work, R-134a refrigerant has been replaced by R600a refrigerant as a working fluid inside the capillary tube, and the capillary tube design has been modified by altering length and diameter, which were obtained from reputable literature. The analysis is carried out using the ANSYS CFX 16.2 software. The results show thatutilising a small diameter and a long length (R600a refrigerant flow) is superior to the present helical capillary tube. The most appropriate helical coiled design with a diameter of 0.8 mm and a length of 3 m is proposed. Keywords: Capillary Tube, Condenser, Refrigeration effect, CFD.

Experimental study of laminar mixed convection in a rod bundle with mixing vane spacer grids

2017 ◽  
Vol 312 ◽  
pp. 99-105 ◽  
Author(s):  
Lokanath Mohanta ◽  
Fan-Bill Cheung ◽  
Stephen M. Bajorek ◽  
Kirk Tien ◽  
Chris L. Hoxie
Keyword(s):  
Experimental Study ◽  
Mixed Convection ◽  
Spacer Grids ◽  
Rod Bundle ◽  
Laminar Mixed Convection
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