scholarly journals Regenerated Marine Gas Turbines: Part II — Regenerator Technology and Heat Exchanger Sizing

1982 ◽  
Author(s):  
J. W. Watts ◽  
T. L. Bowen
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Performance Improvement ◽  
Gas Turbines ◽  
Performance Parameters ◽  
Next Generation ◽  
Plate Spacing ◽  
Naval Ship ◽  
And Performance ◽  
Regenerative Cycle

Analytical studies are currently being conducted by the David Taylor Naval Ship R&D Center to assess the suitability of regenerative-cycle and intercooled, regenerative-cycle gas turbines for naval applications. This paper is the second part of a two-part paper which discusses results of initial investigations to identify attractive engine concepts based on existing turbomachinery and to consider the regenerator technology required to develop these engine concepts. Part I of the paper analyzed existing and next generation engines for performance improvement. Part II includes: definitions of performance parameters such as effectiveness and pressure drop, a discussion of regenerator types, and comments on regenerator materials, life, maintenance, and fouling. Tradeoffs between size, weight, and performance of plate-fin recuperators are examined using two of the hypothetical engines from Part I as examples. Results are compared for several different recuperator matrices to illustrate the effects of air-side and gas-side fin density and plate spacing on size, weight, and performance.

Regenerated Marine Gas Turbines: Part I — Cycle Selection and Performance Estimation

1982 ◽  
Author(s):  
T. L. Bowen ◽  
J. C. Ness
Keyword(s):  
Heat Exchangers ◽  
Gas Turbines ◽  
Performance Estimation ◽  
Simple Cycle ◽  
Performance Trends ◽  
Naval Ship ◽  
Marine Engines ◽  
Improved Performance ◽  
And Performance ◽  
Regenerative Cycle

Analytical studies are currently being conducted by the David Taylor Naval Ship R&D Center to assess the suitability of regenerative-cycle and intercooled, regenerative-cycle gas turbines for naval applications. This paper, which is presented in two parts, discusses results of initial investigations to identify attractive engine concepts based on existing turbomachinery and to consider the regenerator technology required to develop these engine concepts. Part I of the paper deals with the attractive engine concepts. A survey of simple-cycle engines rated from 2500 to 50,000 hp (2 to 37 MW) was conducted to determine the cycle conditions, performance characteristics, and mechanical configurations of current marine gas turbines. Comparative cycle studies were performed to establish the performance trends of the simple, regenerative, intercooled-simple, and intercooled-regenerative cycles. Hypothetical engine concepts are described which illustrate the improved performance obtained by adding heat exchangers for regeneration and intercooling to today’s simple-cycle marine engines.

scholarly journals Comparison of a Novel Polymeric Hollow Fiber Heat Exchanger and a Commercially Available Metal Automotive Radiator

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1175
Author(s):  
Tereza Kroulíková ◽  
Tereza Kůdelová ◽  
Erik Bartuli ◽  
Jan Vančura ◽  
Ilya Astrouski
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Hollow Fiber ◽  
Pressure Loss ◽  
Air Flow ◽  
Performance Parameters ◽  
University Of Technology ◽  
Flat Tubes ◽  
And Performance ◽  
Louvered Fins

A novel heat exchanger for automotive applications developed by the Heat Transfer and Fluid Flow Laboratory at the Brno University of Technology, Czech Republic, is compared with a conventional commercially available metal radiator. The heat transfer surface of this heat exchanger is composed of polymeric hollow fibers made from polyamide 612 by DuPont (Zytel LC6159). The cross-section of the polymeric radiator is identical to the aluminum radiator (louvered fins on flat tubes) in a Skoda Octavia and measures 720 × 480 mm. The goal of the study is to compare the functionality and performance parameters of both radiators based on the results of tests in a calibrated air wind tunnel. During testing, both heat exchangers were tested in conventional conditions used for car radiators with different air flow and coolant (50% ethylene glycol) rates. The polymeric hollow fiber heat exchanger demonstrated about 20% higher thermal performance for the same air flow. The efficiency of the polymeric radiator was in the range 80–93% and the efficiency of the aluminum radiator was in the range 64–84%. The polymeric radiator is 30% lighter than its conventional metal competitor. Both tested radiators had very similar pressure loss on the liquid side, but the polymeric radiator featured higher air pressure loss.

Parametric Analysis of Existing Gas Turbines With Inlet Evaporative and Overspray Fogging

2005 ◽  
Vol 127 (1) ◽  
pp. 145-158 ◽  
Author(s):  
R. Bhargava ◽  
C. B. Meher-Homji
Keyword(s):  
Gas Turbine ◽  
Performance Improvement ◽  
Gas Turbines ◽  
Parametric Analysis ◽  
Design Parameters ◽  
Performance Parameters ◽  
Heavy Duty ◽  
Wide Range ◽  
The World ◽  
Turbine Design

With deregulation in the power generation market and a need for flexibility in terms of power augmentation during the periods of high electricity demand, power plant operators all over the world are exploring means to augment power from both the existing and new gas turbines. An approach becoming increasingly popular is that of the high pressure inlet fogging. In this paper, the results of a comprehensive parametric analysis on the effects of inlet fogging on a wide range of existing gas turbines are presented. Both evaporative and overspray fogging conditions have been analyzed. The results show that the performance parameters indicative of inlet fogging effects have a definitive correlation with the key gas turbine design parameters. In addition, this study indicates that the aeroderivative gas turbines, in comparison to the heavy-duty industrial machines, have higher performance improvement due to inlet fogging effects. Plausible reasons for the observed trends are discussed. This paper represents the first systematic study on the effects of inlet fogging for a large number (a total of 67) of gas turbines available from the major gas turbine manufacturers.

MoS2-capped CuxS nanocrystals: a new heterostructured geometry of transition metal dichalcogenides for broadband optoelectronics

2019 ◽  
Vol 6 (3) ◽  
pp. 587-594 ◽  
Author(s):  
Yuan Li ◽  
Akshay A. Murthy ◽  
Jennifer G. DiStefano ◽  
Hee Joon Jung ◽  
Shiqiang Hao ◽  
...  
Keyword(s):  
Transition Metal ◽  
Performance Improvement ◽  
Transition Metal Dichalcogenides ◽  
Band Alignment ◽  
Next Generation ◽  
Semiconductor Electronics ◽  
Metal Dichalcogenides ◽  
And Performance

Heterostructuring of different transition metal dichalcogenides (TMDs) leads to interesting band alignment and performance improvement, and thus enables new routes for the development of materials for next-generation semiconductor electronics.

Parametric Analysis of Existing Gas Turbines With Inlet Evaporative and Overspray Fogging

2002 ◽  
Author(s):  
R. Bhargava ◽  
C. B. Meher-Homji
Keyword(s):  
Gas Turbine ◽  
Performance Improvement ◽  
Gas Turbines ◽  
Parametric Analysis ◽  
Design Parameters ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Performance Parameters ◽  
Wide Range ◽  
Turbine Design

With deregulation in the power generation market and the need for flexibility in terms of power augmentation during periods of high electricity demand, power plant operators all over the world are exploring means to augment power from both existing and new gas turbines. An approach becoming increasingly popular is that of high pressure fogging. In this paper, the results of a comprehensive parametric analysis on the effects of inlet fogging on a wide range of existing gas turbines have been presented. Both evaporative and overspray fogging conditions have been analyzed. The results of this study show that the performance parameters indicative of inlet fogging effects have definitive correlation with the key gas turbine design parameters. In addition, this study indicates that aeroderivative gas turbines, in comparison to the industrial machines, have higher performance improvement due to the inlet fogging effects. Plausible reasons for the observed trends are discussed in this paper. This paper represents the first systematic study on the effects of inlet fogging for a large number (a total of 67) of gas turbine engines available from major gas turbine manufacturers.

RESEARCH OF HEAT TRANSFER AND PRESSURE DROP CHARACTERISTIC OF CONCAVO-CONVEX PLATE

2013 ◽  
Vol 21 (02) ◽  
pp. 1350012 ◽  
Author(s):  
AKIRA KANEKO ◽  
MASAFUMI KATSUTA ◽  
YUKI HAMANO
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Performance Improvement ◽  
System Performance ◽  
Air Conditioning ◽  
Parallel Plates ◽  
Pump System ◽  
Air Conditioning System ◽  
Heat Pump System

For an automobile air-conditioning system, performance improvement of the heat exchanger is needed to fit in the change of refrigerant and heat pump system. In this study, the heat transfer and pressure drop characteristic of air flow between parallel plates with concavity and convexity is grasped, and the possibility of using a fin-less heat exchanger is considered analytically. And it has been shown that a fin-less heat exchanger has the possibility of increasing performance compared to a conventional heat exchanger, which uses a corrugated louver fin.

scholarly journals PARAMETRIC INVESTIGATION OF ORGANIC RANKINE CYCLE EVAPORATOR FOR LOW TEMPERATURE APPLICATIONS

2019 ◽  
Vol 16 (2) ◽  
pp. 130
Author(s):  
Upadhyaya Suhas ◽  
Gumtapure Veershetty
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Plate Heat Exchanger ◽  
Inlet Temperature ◽  
Work Output ◽  
Plate Spacing ◽  
Network Output ◽  
Plate Width

The present work deals with the development of thermodynamic model of low temperature basic Organic Rankine Cycle (ORC) system and a chevron plate heat exchanger evaporator sub-model using Engineering Equation Solver (EES). Work output is evaluated using the ORC thermodynamic model, while the evaporator sub-model calculates the total surface area of the heat exchanger. Using these mathematical models, the effect of evaporation pressure, expander inlet temperature and pinch point temperature difference (PPTD) on the network output and evaporator cost are studied. In addition to this, the effect of plate spacing and plate width of chevron plate heat exchanger on pressure drop and evaporator cost are analyzed in detail. Finally, thermodynamic and geometric optimization is carried out using genetic algorithm to identify the optimum parameters at which the network output is maximized and pressure drop in the evaporator is minimized. Sensitivity analysis showed that optimum evaporator pressure existed at which network output is maximum. Thermodynamic optimization showed that work output was maximum (5.03 kW) at evaporator pressure of 5.77 bar. No improvement in the work output was seen with increase in PPTD and expander inlet temperature. Increase in plate width and plate spacing led to increase in evaporator cost and decrease in pressure drop.

Optimization of Diffuser/Nozzle Elements for Rectification Valveless Micropumps

2010 ◽  
Author(s):  
A. Azarbadegan ◽  
C. A. Cortes-Quiroz ◽  
E. Moeendarbary ◽  
Ian Eames
Keyword(s):  
Pressure Drop ◽  
Design Methodology ◽  
Pressure Rise ◽  
Response Surfaces ◽  
Optimization Techniques ◽  
Performance Parameters ◽  
Multi Objective Genetic Algorithm ◽  
Optimization Methodology ◽  
And Performance ◽  
Compact Design

There has been a growing interest in understanding the flow behaviour inside diffuser/nozzle elements in order to identify performance characteristics of these elements for micropump applications. Flat-walled diffuser/nozzle element is the most commonly used type for valveless micropump applications due to its ease of fabrication and compact design. In this paper, we study generic flat-walled diffuser/nozzle elements and apply optimization techniques to explore how the pumping efficiency can be improved by changing geometry to provide higher rectification efficiency and lower pressure drop in rectification valveless micropumps. The primary motivation for this study is to evaluate the performance of flat-walled diffuser/nozzle elements based on geometry variations under several Reynolds numbers (Re). In this study we employ a design methodology for diffuser/nozzle elements that incorporates computational fluid dynamics (CFD) within an optimization methodology. To start the process a series of geometric parameters are selected including element neck width, depth, divergence angle, and entrance fillet radius. Then, the pressure drop and rectification property of an element are calculated as performance parameters, i.e., by varying the geometry it is desirable to maximise pressure rise and the rectification property of the element. Design of experiments (DOE) is employed to generate the experimental table which corresponds to different geometries representing the design space. These limited numbers of geometries generated by DOE are evaluated by using CFD to obtain corresponding performance parameters. By preparing all the design and performance parameters, Surrogate model (SM) technique is applied to obtain the relationship (approximation function) between design and performance parameters. Eventually, based on the developed approximation functions or response surfaces, a multi-objective genetic algorithm (MOGA) is employed to maximise pressure rise and rectification property of diffuser/nozzle element. This design methodology is a very powerful tool to design and optimise flat-walled diffuser/nozzle elements for micropump applications and can speed up the micropump design process significantly.

Sign in / Sign up

Export Citation Format

Share Document