First Experimental Results on a Silicon-Nitride Recuperator With Six Heat Exchanger Elements

1979 ◽  
Author(s):  
S. Forster ◽  
H. Jaegers ◽  
M. Kleemann
Keyword(s):  
Heat Exchanger ◽  
Gas Turbines ◽  
Design Principle ◽  
Experimental Results ◽  
Test Facility ◽  
Partial Rupture ◽  
Sealing Performance ◽  
Thermodynamic Measurements ◽  
Ceramic Recuperator ◽  
Shaft Power

A prototype ceramic recuperator consisting of six heat exchanger elements of Si3N4, being arranged side by side in a self-sealing and self-supporting configuration, was investigated experimentally with respect to the heat transfer-, friction- and mechanical-properties as well as to the sealing performance. The heat exchanger elements are developed in collaboration by Kernforschungsanlage Jülich GmbH (KFA) and Rosenthal Technik AG (RTAG). The recuperator arrangement corresponds well to an unique design principle for small automotive “ceramic” gas turbines. The thermodynamic measurements were carried out with air, electrically heated up to temperatures of about 100 C, and at pressures on the HP-side up to about 2 bar. The self-sealing and self-supporting heat exchanger arrangement promises to be satisfying for vehicular application purposes. Partial rupture of heat exchanger walls in the prototype-elements began at a pressure difference of about 3 bar. On the basis of the experimental results, a design of a vehicular gas turbine for 70-Kw shaft power and with heat exchanger elements for advanced fabrication technique is presented. A planned test facility for gas temperatures up to about 1200 C and with a new set of heat exchanger elements from Si3N4 or SiC is described briefly.

Design and Testing of a Can Combustor for a Small Gas Turbine Application

2013 ◽  
Author(s):  
K. V. L. Narayana Rao ◽  
N. Ravi Kumar ◽  
G. Ramesha ◽  
M. Devathathan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Pressure Loss ◽  
High Energy ◽  
Experimental Results ◽  
High Mass ◽  
Test Facility ◽  
Design Requirements

Can type combustors are robust, with ease of design, manufacturing and testing. They are extensively used in industrial gas turbines and aero engines. This paper is mainly based on the work carried out in designing and testing a can type combustion chamber which is operated using JET-A1 fuel. Based on the design requirements, the combustor is designed, fabricated and tested. The experimental results are analysed and compared with the design requirements. The basic dimensions of the combustor, like casing diameter, liner diameter, liner length and liner hole distribution are estimated through a proprietary developed code. An axial flow air swirler with 8 vanes and vane angle of 45 degree is designed to create a re-circulation zone for stabilizing the flame. The Monarch 4.0 GPH fuel nozzle with a cone angle of 80 degree is used. The igniter used is a high energy igniter with ignition energy of 2J and 60 sparks per minute. The combustor is modelled, meshed and analysed using the commercially available ansys-cfx code. The geometry of the combustor is modified iteratively based on the CFD results to meet the design requirements such as pressure loss and pattern factor. The combustor is fabricated using Ni-75 sheet of 1 mm thickness. A small combustor test facility is established. The combustor rig is tested for 50 Hours. The experimental results showed a blow-out phenomenon while the mass flow rate through the combustor is increased beyond a limit. Further through CFD analysis one of the cause for early blow out is identified to be a high mass flow rate through the swirler. The swirler area is partially blocked and many configurations are analysed. The optimum configuration is selected based on the flame position in the primary zone. The change in swirler area is implemented in the test model and further testing is carried out. The experimental results showed that the blow-out limit of the combustor is increased to a good extent. Hence the effect of swirler flow rate on recirculation zone length and flame blow out is also studied and presented. The experimental results showed that the pressure loss and pattern factor are in agreement with the design requirements.

Recent Advances in High Temperature Ceramic Regenerators for Externally Fired Gas Turbines: Theoretical and Experimental Results

2010 ◽  
Author(s):  
Alfonso Acun˜as ◽  
Jon Huete ◽  
Ibon Amallobieta
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbines ◽  
Experimental Results ◽  
Gasification Process ◽  
Low Leakage ◽  
New Applications ◽  
Solid Biomass ◽  
Very High ◽  
Vast Range

Recent development in ceramic regenerators opens a vast range of new applications. Externally fired gas turbines have been limited by the efficiency of the process of transferring the heat to the turbine. So far, both the gasification process of the indirect routes and the heat exchanger efficiency of the direct routes have restricted the efficiency of the whole system to unacceptable values. A new concept of ceramic regenerator has been designed and tested, showing more than 95% efficiency at very high temperatures with low leakage and minimum pressure drop. The design, theoretical and experimental results are explained in the paper. The possibility of using solid biomass in small turbines and microturbines may turn out to be an attractive solution for agricultural and forestry residue revalorization.

scholarly journals A Low NOx Combustion System and a Ceramic Cross Flow Heat Exchanger for Small Gas Turbines

1987 ◽  
Author(s):  
Siegfried Förster ◽  
Peter Quell
Keyword(s):  
Heat Exchanger ◽  
Gas Turbines ◽  
Cross Flow ◽  
Fuel Oil ◽  
Actual State ◽  
Combustion System ◽  
Air Temperatures ◽  
Shaft Power ◽  
Flow Heat ◽  
Gas Turbine Cycle

A new low NOx oil-combustion system with superheated steam fuel evaporation prior to combustion has been found especially feasible for open cycle gas turbines with high turbine inlet temperatures and ceramic cross flow heat exchanger. The actual state of development of both the low NOx light fuel-oil combustion system and ceramic heat exchanger elements, especially the cross flow type, is outlined in this paper. The use of this combustion system results in considerably lower combustion temperatures in the primary combustion zone, reducing the NOx-production even at high air temperatures when the air is preheated in the heat exchanger. The water vapour used for the evaporation of the fuel oil before combustion has an improving effect on the cycle efficiency comparable to the Cheng-dual-fluid-cycle. Illustrative evaluations for a gas turbine cycle for a shaft power of 70 kW are given.

A Proposal for Shaft Power Prediction of Centrifugal Compressor Under Wet Gas Conditions

2018 ◽  
Author(s):  
Daisuke Kawaguchi ◽  
Katsutoshi Kobayashi ◽  
Lars Eirik Bakken
Keyword(s):  
Liquid Film ◽  
Centrifugal Force ◽  
Centrifugal Compressor ◽  
Science And Technology ◽  
Experimental Results ◽  
Test Facility ◽  
Power Prediction ◽  
Trailing Edge ◽  
Wet Gas ◽  
Shaft Power

In this study, the influence of wet gas on the fluid performance of a centrifugal compressor was evaluated using a test facility in the Norwegian University of Science and Technology, NTNU. The experimental results indicated that the polytropic efficiency decreased with increases in LMF. One factor of decrease of the polytropic efficiency was an increase in the shaft power. Moreover, we hypothesized that the liquid film on the inner wall of the impeller was discharged from the trailing edge at a circumferential speed by a centrifugal force. Then an expression to predict the shaft power under wet gas conditions on the basis of the hypothesis was built and it was verified that the ratio of the predicted and experimental shaft power agreed well.

Transient Regime Simulation From Idle to Maximum Take-Off Flight Conditions of Cooled Cooling Air Heat Exchanger for an Aero Gas Turbine Heat Management

2019 ◽  
Author(s):  
Alberto Mucci ◽  
Foster Kwame Kholi ◽  
Man Yeong Ha ◽  
June Kee Min ◽  
Peter A. Beecroft ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Gas Turbines ◽  
Experimental Testing ◽  
Dynamic Performance ◽  
Test Facility ◽  
Operating Pressure ◽  
Heat Management ◽  
Experimental Conditions ◽  
Cooling Air ◽  
Real Scale

Abstract The quest for improving the thermal efficiency of gas turbines has raised the turbine entry temperatures (TET) and hence the operating pressure ratios (OPR). However, the combination of high TET and high cooling flow temperature makes the cooling of the hot sections more challenging. A cooled cooling air heat exchanger (CCAHX) can be used to cool the high-temperature compressor offtake, showing improved steady aerothermal performance in terms of pressure and temperature. Presented here is the experimental testing of the CCAHX and the process used to generate a highly representative transient simulation of its dynamic performance between idle and Maximum Take-Off (MTO) flight conditions. Said simulation is primarily used to predict the performance during further experiments. Due to the harsh experimental conditions, the simulation guarantees safe operations of the test facility while advising on the right procedures to use during real scale tests. Due to the complex internal structure of the heat exchanger, a one-dimensional computational fluid dynamics (CFD) commercial software was employed to validate the models using results from steady-state data for a single CCAHX unit. Derived procedures from the 1D analysis are used to guide the transient testing at real scale flight conditions, where the core and fan flows are thermally-linked to two CCAHXs in a back-to-back configuration. Results show that the approach considered here can correctly predict the performance of a complex heat exchanger system in transient, fast-changing operations, as calculations in real flight conditions showed good agreement with experimental results of a real scale test.

Measurements and Modeling of Ingress in a New 1.5-Stage Turbine Research Facility

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Marios Patinios ◽  
James A. Scobie ◽  
Carl M. Sangan ◽  
J. Michael Owen ◽  
Gary D. Lock
Keyword(s):  
Theoretical Model ◽  
Gas Turbines ◽  
Test Facility ◽  
Radial Clearance ◽  
Operating Life ◽  
The Core ◽  
Wide Range ◽  
Purge Flow ◽  
Rotor Disk ◽  
Engine Components

In gas turbines, hot mainstream flow can be ingested into the wheel-space formed between stator and rotor disks as a result of the circumferential pressure asymmetry in the annulus; this ingress can significantly affect the operating life, performance, and integrity of highly stressed, vulnerable engine components. Rim seals, fitted at the periphery of the disks, are used to minimize ingress and therefore reduce the amount of purge flow required to seal the wheel-space and cool the disks. This paper presents experimental results from a new 1.5-stage test facility designed to investigate ingress into the wheel-spaces upstream and downstream of a rotor disk. The fluid-dynamically scaled rig operates at incompressible flow conditions, far removed from the harsh environment of the engine which is not conducive to experimental measurements. The test facility features interchangeable rim-seal components, offering significant flexibility and expediency in terms of data collection over a wide range of sealing flow rates. The rig was specifically designed to enable an efficient method of ranking and quantifying the performance of generic and engine-specific seal geometries. The radial variation of CO2 gas concentration, pressure, and swirl is measured to explore, for the first time, the flow structure in both the upstream and downstream wheel-spaces. The measurements show that the concentration in the core is equal to that on the stator walls and that both distributions are virtually invariant with radius. These measurements confirm that mixing between ingress and egress is essentially complete immediately after the ingested fluid enters the wheel-space and that the fluid from the boundary layer on the stator is the source of that in the core. The swirl in the core is shown to determine the radial distribution of pressure in the wheel-space. The performance of a double radial-clearance seal is evaluated in terms of the variation of effectiveness with sealing flow rate for both the upstream and the downstream wheel-spaces and is found to be independent of rotational Reynolds number. A simple theoretical orifice model was fitted to the experimental data showing good agreement between theory and experiment for all cases. This observation is of great significance as it demonstrates that the theoretical model can accurately predict ingress even when it is driven by the complex unsteady pressure field in the annulus upstream and downstream of the rotor. The combination of the theoretical model and the new test rig with its flexibility and capability for detailed measurements provides a powerful tool for the engine rim-seal designer.

Effects of Wind on the Heat Flow of FPSO Topsides Subject to Fire: An Experimental and Numerical Study

2010 ◽  
Author(s):  
Joon Young Yoon ◽  
Seong Hwan Kim ◽  
Gwon Cheol Yu ◽  
Jung Kwan Seo ◽  
Bong Ju Kim ◽  
...  
Keyword(s):  
Thermal Diffusion ◽  
Numerical Study ◽  
Wind Tunnel Test ◽  
Experimental Results ◽  
Test Facility ◽  
Test Model ◽  
Cfd Simulations ◽  
Fire Engineering ◽  
Diffusion Characteristics ◽  
Fire Loads

The aim of this paper is to examine the effect of wind on the thermal diffusion characteristics of floating production storage and offloading (FSPO) topside models subject to fire. It is motivated by the need to identify the fire loads on FPSO topsides, taking into account the effects of wind speed and direction. The results of an experimental and numerical study undertaken for these purposes are reported here. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) [1]. An experiment was performed on a 1/14-scale FPSO topside model using a wind tunnel test facility. The locations of the heat source of the fire were varied, as were the speed and direction of the wind, and the temperature distribution was measured. Computational fluid dynamics (CFD) simulations using the ANSYS CFX program were performed on the test model, with the results obtained compared with the experimental results. It is concluded that wind has a significant effect on the thermal diffusion characteristics of the test model and that the CFD simulations are in good agreement with the experimental results. The insights developed in this study will be very useful for the fire engineering of FPSO topsides.

Status Report—Advanced Heat Exchanger Technology for a CCGT Power Generation System

1983 ◽  
Vol 105 (2) ◽  
pp. 348-353 ◽  
Author(s):  
D. E. Wright ◽  
L. L. Tignac
Keyword(s):  
Power Generation ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
Ceramic Materials ◽  
Department Of Energy ◽  
Test Facility ◽  
Status Report ◽  
Test Results ◽  
Generation System ◽  
Power Generation System

Rocketdyne is under contract to the Department of Energy for the development of heat exchanger technology that will allow coal to be burned for power generation and cogeneration applications. This effort involves both atmospheric fluidized bed and pulverized coal combustion systems. In addition, the heat exchanger designs cover both metallic and ceramic materials for high-temperature operations. This paper reports on the laboratory and small AFB test results completed to date. It also covers the design and installation of a 6×6 ft atmospheric fluidized bed test facility being used to correlate and expand the knowledge gained from the initial tests. The paper concludes by showing the direction this technology is taking and outlining the steps to follow in subsequent programs.

Processing Techniques of a Silicon Carbide Heat Exchanger and its Capable Properties – A Review

2015 ◽  
Vol 787 ◽  
pp. 513-517 ◽  
Author(s):  
R. Pachaiyappan ◽  
R. Gopinath ◽  
S. Gopalakannan
Keyword(s):  
Silicon Carbide ◽  
Heat Exchanger ◽  
Gas Turbines ◽  
Cooling System ◽  
Composite Ceramic ◽  
Processing Technique ◽  
Full Potential ◽  
Absorption Chillers ◽  
Evaporative Cooling System ◽  
Processing Techniques

Silicon carbides is a composite ceramic material produced from inorganic non-metallic substances, formed from the molten mass which solidifies on cooling and simultaneously matured by the action of heat. It is used in various applications such as grinding wheels, filtration of gases and water, absorption, catalyst supports, concentrated solar powers, thermoelectric conversion etc. The modern usage of silicon carbide is fabricated as a heat exchanger for high temperature applications. Leaving behind steel and aluminium, silicon carbide has an excellent temperature withstanding capability of 1425°C. It is resistant to corrosion and chemical erosion. Modern fusion reactors, Stirling cycle based gas turbines, evaporators in evaporative cooling system for air condition and generator in LiBr/H2O absorption chillers for air conditioning those systems heat transfer rate can be improved by replacing a present heat exchanger with silicon carbide heat exchanger. This review presents a detailed discussion about processing technique of such a silicon carbide. Modern known processing techniques are partial sintering, direct foaming, replica, sacrificial template and bonding techniques. The full potential of these materials can be achieved when properties are directed over specified application. While eyeing over full potential it is highly dependent on processing techniques.

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