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Article
Publication date: 29 July 2019

Peyman Maghsoudi, Sadegh Sadeghi, Qingang Xiong and Saiied Mostafa Aminossadati

Because of the appreciable application of heat recovery systems for the increment of overall efficiency of micro gas turbines, promising evaluation and optimization are…

Abstract

Purpose

Because of the appreciable application of heat recovery systems for the increment of overall efficiency of micro gas turbines, promising evaluation and optimization are crucial. This paper aims to propose a multi-factor theoretical methodology for analysis, optimization and comparison of potential plate-fin recuperators incorporated into micro gas turbines. Energetic, exergetic, economic and environmental factors are covered.

Design/methodology/approach

To demonstrate applicability and reliability of the methodology, detailed thermo-hydraulic analysis, sensitivity analysis and optimization are conducted on the recuperators with louver and offset-strip fins using a genetic algorithm. To assess the relationship between investment cost and profit for the recuperated systems, payback period (PBP), which incorporates all the factors is used as the universal objective function. To compare the performance of the recuperated and non-recuperated systems, exergy efficiency, exergy destruction and corresponding cost rate, fuel consumption and environmental damage cost rates, capital and operational cost rates and acquired profit rates are determined.

Findings

Based on the results, optimal PBP of the louvered-fin recuperator (147 days) is slightly lower than that with offset-strip fins (153 days). The highest profit rate is acquired by reduction of exergy destruction cost rate and corresponding decrements for louver and offset-strip fins are 2.3 and 3.9 times compared to simple cycle, respectively.

Originality/value

This mathematical study, for the first time, focuses on introducing a reliable methodology, which covers energetic, exergetic, economic and environmental points of view beneficial for design and selection of efficient plate-fin recuperators for micro gas turbine applications.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 4 July 2008

Colin F. McDonald, Aristide F. Massardo, Colin Rodgers and Aubrey Stone

This paper seeks to evaluate the potential of heat exchanged aeroengines for future Unmanned Aerial Vehicle (UAV), helicopter, and aircraft propulsion, with emphasis…

Abstract

Purpose

This paper seeks to evaluate the potential of heat exchanged aeroengines for future Unmanned Aerial Vehicle (UAV), helicopter, and aircraft propulsion, with emphasis placed on reduced emissions, lower fuel burn, and less noise.

Design/methodology/approach

Aeroengine performance analyses were carried out covering a wide range of parameters for more complex thermodynamic cycles. This led to the identification of major component features and the establishing of preconceptual aeroengine layout concepts for various types of recuperated and ICR variants.

Findings

Novel aeroengine architectures were identified for heat exchanged turboshaft, turboprop, and turbofan variants covering a wide range of applications. While conceptual in nature, the results of the analyses and design studies generally concluded that heat exchanged engines represent a viable solution to meet demanding defence and commercial aeropropulsion needs in the 2015‐2020 timeframe, but they would require extensive development.

Research limitations/implications

As highlighted in Parts I and II, early development work was focused on the use of recuperation, but this is only practical with compressor pressure ratios up to about 10. For today's aeroengines with pressure ratios up to about 50, improvement in SFC can only be realised by incorporating intercooling and recuperation. The new aeroengine concepts presented are clearly in an embryonic stage, but these should enable gas turbine and heat exchanger specialists to advance the technology by conducting more in‐depth analytical and design studies to establish higher efficiency and “greener” gas turbine aviation propulsion systems.

Originality/value

It is recognised that meeting future environmental and economic requirements will have a profound effect on aeroengine design and operation, and near‐term efforts will be focused on improving conventional simple‐cycle engines. This paper has addressed the longer‐term potential of heat exchanged aeroengines and has discussed novel design concepts. A deployment strategy, aimed at gaining confidence with emphasis placed on assuring engine reliability, has been suggested, with the initial development and flight worthiness test of a small recuperated turboprop engine for UAVs, followed by a larger recuperated turboshaft engine for a military helicopter, and then advancement to a larger and far more complex ICR turbofan engine.

Details

Aircraft Engineering and Aerospace Technology, vol. 80 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 16 May 2008

Colin F. McDonald, Aristide F. Massardo, Colin Rodgers and Aubrey Stone

To advance the design of heat exchanged gas turbine propulsion aeroengines utilising experience gained from early development testing, and based on technologies prevailing…

Abstract

Purpose

To advance the design of heat exchanged gas turbine propulsion aeroengines utilising experience gained from early development testing, and based on technologies prevailing in the 1970‐2000 time frame.

Design/methodology/approach

With emphasis on recuperated helicopter turboshaft engines, particularly in the 1,000 hp (746 kW) class, detailed performance analyses, parametric trade‐off studies, and overall power plant layouts, based on state‐of‐the‐art turbomachinery component efficiencies and high‐temperature heat exchanger technologies, were undertaken for several engine configuration concepts.

Findings

Using optimised cycle parameters, and the selection of a light weight tubular heat exchanger concept, an attractive engine architecture was established in which the recuperator was fully integrated with the engine structure. This resulted in a reduced overall engine weight and lower specific fuel consumption, and represented a significant advancement in technology from the modified simple‐cycle engines tested in the late 1960s.

Practical implications

While heat exchanged engine technology advancements were projected, there were essentially two major factors that essentially negated the continued study and development of recuperated aeroengines, namely again as mentioned in Part I, the reduced fuel consumption was not regarded as an important economic factor in an era of low‐fuel cost, and more importantly in this time frame very significant simple‐cycle engine performance advancements were made with the use of significantly higher pressure ratios and increased turbine inlet temperatures. Simply stated, recuperated variants could not compete with such a rapidly moving target.

Originality/value

Establishing an engine design concept in which the recuperator was an integral part of the engine structure to minimise the overall power plant weight was regarded as a technical achievement. Such an approach, together with the emergence of lighter weight recuperators of assured structural integrity, would find acceptance around the year 2000 when there was renewed interest in the use of more efficient heat exchanged variants towards the future goal of establishing “greener” aeroengines, and this is discussed in Part III of this paper.

Details

Aircraft Engineering and Aerospace Technology, vol. 80 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 21 March 2008

Colin F. McDonald, Aristide F. Massardo, Colin Rodgers and Aubrey Stone

Interest is currently being expressed in heat exchanged propulsion gas turbines for a variety of aeroengine applications, and in support of this, the aim of this paper is…

Abstract

Purpose

Interest is currently being expressed in heat exchanged propulsion gas turbines for a variety of aeroengine applications, and in support of this, the aim of this paper is to evaluate the relevance of experience gained from development testing of several recuperated aeroengines in the USA in the late 1960s.

Design/methodology/approach

Technology status, including engine design features, performance, and specific weight of recuperated propulsion gas turbines based on radial and axial turbomachinery, that were development tested in the power range of about 300 to 4,000 hp (224 to 2,984 kW) is discussed in Part I.

Findings

A successful flight worthiness test was undertaken in the USA of a helicopter powered solely by a recuperated turboshaft engine and this demonstrated a specific fuel consumption reduction of over 25 percent compared with the simple‐cycle engine. However; in an era of low‐fuel cost, and uncertainty about the long‐term structural integrity of the high‐temperature heat exchanger, further development work was not undertaken.

Practical implications

The gas turbines tested were based on conventional simple‐cycle engines with essentially “bolted‐on” recuperators. Optimum approaches to minimize engine overall weight were needed in which the recuperator was integrated with the engine structure from the onset of design, and these are discussed in Part II.

Originality/value

Based on engine hardware testing, a formidable technology base was established, which although dated, could provide insight into the technical issues likely to be associated with the introduction of future heat exchanged aeroengines. These are projected to have the potential for reduced fuel burn, less emissions, and lower noise, and recuperated and intercooled turboshaft, turboprop, and turbofan variants are discussed in Part III.

Details

Aircraft Engineering and Aerospace Technology, vol. 80 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 20 June 2019

Ali Akbar Abbasian Arani, Ali Arefmanesh and Hamidreza Ehteram

The purpose of this paper is to recommend a validated numerical model for simulation the flue gases heat recovery recuperators. Due to fulfill of this demand, the…

Abstract

Purpose

The purpose of this paper is to recommend a validated numerical model for simulation the flue gases heat recovery recuperators. Due to fulfill of this demand, the influences of ash fouling characteristics during the transient/steady-state simulation and optimization of a 3D complex heat exchanger equipped with inner plain fins and side plate fins are studied.

Design/methodology/approach

For the particle dispersion modeling, the discrete phase model is applied and the flow field has been solved using SIMPLE algorithm.

Findings

According to obtained results, for the recuperator equipped with combine inner plain and side plate fins, determination of ash fouling characteristics is really important, effective and determinative. It is clear that by underestimating the ash fouling characteristics, the achieved results are wrong and different with reality.

Originality/value

Finally, the configuration with inner plain fins with characteristics of: di =5 mm, do = 6 mm, dg = 2 mm, dk = 3 mm and NIPFT = 9 and side plate fins with characteristics of: TF = 3 mm, PF = 19 mm, NSPF = 17·2 = 34, WF = 10 mm, HF = 25 mm, LF = 24 mm and ß = 0° is introduced as the optimum model with the best performance among all studied configurations.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 1 September 2000

Esa Utriainen and Bengt Sundén

A three‐dimensional numerical study was conducted to assess the hydraulic and heat transfer performance of a primary surface type heat exchanger surface, called the…

Abstract

A three‐dimensional numerical study was conducted to assess the hydraulic and heat transfer performance of a primary surface type heat exchanger surface, called the trapezoidal cross wavy (TCW) duct. This duct is similar to the ducts being used in compact recuperators manufactured by Solar Turbines Inc. The governing equations, i.e. the mass conservation equation, Navier‐Stokes equations and the energy equation, are solved numerically by a finite volume method for boundary fitted coordinates. Periodic boundary conditions are imposed in the main flow direction. In this particular case laminar convective flow and heat transfer prevail. Owing to the complex geometry a complicated secondary flow pattern appears in the cross‐sectional planes. Details of the recuperator ducts and the numerical method, as well as relevant results, are presented. The overall results are also compared with corresponding results (i.e. Nu numbers, friction factors) of straight ducts with various cross‐sectional shapes.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 10 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 23 March 2020

Benoit Picard, Mathieu Picard, Jean-Sébastien Plante and David Rancourt

The limited energy density of batteries generates the need for high-performance power sources for emerging eVTOL applications with radical operational improvement…

Abstract

Purpose

The limited energy density of batteries generates the need for high-performance power sources for emerging eVTOL applications with radical operational improvement potential over traditional aircraft. This paper aims to evaluate on-design and off-design recuperated turbogenerator performances based on newly developed compression loaded ceramic turbines, the Inside-out Ceramic Turbine (ICT), in order to select the optimum engine configuration for sub-megawatt systems.

Design/methodology/approach

System-level thermal engine modeling is combined with electric generators and power electronics performance predictions to obtain the Pareto front between efficiency and power density for a variety of engine designs, both for recuperated and simple cycle turbines. Part load efficiency for those engines are evaluated, and the results are used for an engine selection based on a simplified eVTOL mission capability.

Findings

By operating with high turbine inlet temperature, variable output speed and adequately sized recuperator, a turbogenerator provides exceptional efficiency at both nominal power and part load operation for a turbomachine, while maintaining the high power density required for aircraft. In application with a high peak-to-cruise power ratio, such power source would provide eight times the range of battery-electric power pack and an 80% improvement over the state-of-the-art simple cycle turbogenerator.

Practical implications

The implementation of a recuperator would provide additional gains especially important for military and on-demand mobility applications, notably reducing the heat signature and noise of the system. The engine low-pressure ratio reduces its complexity and combined with the fuel savings, the system could significantly reduce operational cost.

Originality/value

Implementation of radically new ICT architecture provides the key element to make a sub-megawatt recuperated turbogenerator viable in terms of power density. The synergetic combination of a recuperator, high temperature turbine and variable speed electric generator provides drastic improvement over simple-cycle turbines, making such a system highly relevant as the power source for future eVTOL applications.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 5
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 1 January 1988

S. McLaren

1.1 Metabrasive Ltd — The Company and Product Metabrasive Ltd is a wholly‐owned, British registered, subsidiary of a French Company, Wheelabrator‐Allevard S.A., which is…

Abstract

1.1 Metabrasive Ltd — The Company and Product Metabrasive Ltd is a wholly‐owned, British registered, subsidiary of a French Company, Wheelabrator‐Allevard S.A., which is based in the Isère region of France just north of Grenoble. That Company, which is itself 51% American owned, bought the steel abrasives business from Bradley & Foster Ltd., a part of Staveley Industries, in August 1980.

Details

Anti-Corrosion Methods and Materials, vol. 35 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 September 1987

S. McLaren

Following an in‐depth study of gas usage at Metabrasive undertaken in 1981, it was decided to treat the reduction of hardening furnace gas consumption as a priority and a…

Abstract

Following an in‐depth study of gas usage at Metabrasive undertaken in 1981, it was decided to treat the reduction of hardening furnace gas consumption as a priority and a paper on hardening furnace gas savings was prepared. A detailed monitoring exercise of the “Wellman” conventionally designed furnace, with a 32 air/gas nozzle mix burner system and brick refractory lining, carried out by independent consultants, showed a net gas consumption of 485 kwh/tonne. The first furnace modification at Metabrasive consisted of the fitting of a recuperative burner system with 8 burners and 4 recuperators, a low density solid hearth and ceramic fibre lined walls and roof. Detailed monitoring by the same consultants showed that a combustion air pre‐heat to 350°C was possible yielding a saving of approximately 25% and a pay‐back period of 2 years. Good even heat distribution and shorter heat‐up and cool‐down times were achieved. The second modification was carried out in 1984, with only slight changes in detail. These were the use of fully proportional air/gas controllers instead of a 3‐step system and high density refractory pads in front of the lower burners to eliminate wear caused by high velocity gases. Problems have been experienced with both these units. The refractory inlet quarts to the recuperators were found to be particularly susceptible to oxide attack. They were made using a metallic fibre reinforced refractory which spalled due to growth of the fibres. Clean air is now ducted from outside the plant which has alleviated the problem. The air valve Honeywell control motors we found to be particularly affected by heat, in spite of being provided for this duty. Sheilding has solved this problem. It was planned to modify the third furnace in 1985 with the same, albeit improved, system. However, combustion technology had moved on rapidly and the regenerative burner systems had reached the proven stage. This method was, therefore, adopted for this furnace.

Details

Anti-Corrosion Methods and Materials, vol. 34 no. 9
Type: Research Article
ISSN: 0003-5599

Content available
Article
Publication date: 1 May 1999

Abstract

Details

Facilities, vol. 17 no. 5/6
Type: Research Article
ISSN: 0263-2772

Keywords

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