Fabrication and Performance of a Pin Fin Micro Heat Exchanger

2004 ◽  
Vol 126 (3) ◽  
pp. 434-444 ◽  
Author(s):  
Christophe Marques ◽  
Kevin W. Kelly

Nickel micro pin fin heat exchangers can be electroplated directly onto planar or non-planar metal surfaces using a derivative of the LIGA micromachining process. These heat exchangers offer the potential to more effectively control the temperature of surfaces in high heat flux applications. Of particular interest is the temperature control of gas turbine engine components. The components in the gas turbine engine that require efficient, improved cooling schemes include the gas turbine blades, the stator vanes, the turbine disk, and the combustor liner. Efficient heating of component surfaces may also be required (i.e., surfaces near the compressor inlet to prevent deicing). In all cases, correlations providing the Nusselt number and the friction factor are needed for such micro pin fin heat exchangers. Heat transfer and pressure loss experimental results are reported for a flat parallel plate pin fin micro heat exchanger with a staggered pin fin array, with height-to-diameter ratios of 1.0, with spacing-to-diameter ratios of 2.5 and for Reynolds numbers (based on the hydraulic diameter of the channel) from 4000 to 20,000. The results are compared to studies of larger scale, but geometrically similar, pin fin heat exchangers. To motivate further research, an analytic model is described which uses the empirical results from the pin fin heat exchanger experiments to predict a cooling effectiveness exceeding 0.82 in a gas turbine blade cooling application. As a final point, the feasibility of fabricating a relatively complex micro heat exchanger on a simple airfoil (a cylinder) is demonstrated.

In the past three decades, it is very challenging for the researchers to design and development a best gas turbine engine component. Engine component has to face different operating conditions at different working environments. Nickel based superalloys are the best material to design turbine components. Inconel 718, Inconel 617, Hastelloy, Monel and Udimet are the common material used for turbine components. Directional solidification is one of the conventional casting routes followed to develop turbine blades. It is also reported that the raw materials are heat treated / age hardened to enrich the desired properties of the material implementation. Accordingly they are highly susceptible to mechanical and thermal stresses while operating. The hot section of the turbine components will experience repeated thermal stress. The halides in the combination of sulfur, chlorides and vanadate are deposited as molten salt on the surface of the turbine blade. On prolonged exposure the surface of the turbine blade starts to peel as an oxide scale. Microscopic images are the supportive results to compare the surface morphology after complete oxidation / corrosion studies. The spectroscopic results are useful to identify the elemental analysis over oxides formed. The predominant oxides observed are NiO, Cr2O3, Fe2O3 and NiCr2O4. These oxides are vulnerable on prolonged exposure and according to PB ratio the passivation are very less. In recent research, the invention on nickel based superalloys turbine blades produced through other advanced manufacturing process is also compared. A summary was made through comparing the conventional material and advanced materials performance of turbine blade material for high temperature performance.


2020 ◽  
Vol 19 (4) ◽  
pp. 43-57
Author(s):  
H. H. Omar ◽  
V. S. Kuz'michev ◽  
A. O. Zagrebelnyi ◽  
V. A. Grigoriev

Recent studies related to fuel economy in air transport conducted in our country and abroad show that the use of recuperative heat exchangers in aviation gas turbine engines can significantly, by up to 20...30%, reduce fuel consumption. Until recently, the use of cycles with heat recovery in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of a heat exchanger. Currently, there is a technological opportunity to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focused on setting of the optimization problem and the choice of rational parameters of the thermodynamic cycle parameters of a gas turbine engine with a recuperative heat exchanger. On the basis of the developed method of multi-criteria optimization the optimization of thermodynamic cycle parameters of a helicopter gas turbine engine with a ANSAT recuperative heat exchanger was carried out by means of numerical simulations according to such criteria as the total weight of the engine and fuel required for the flight, the specific fuel consumption of the aircraft for a ton- kilometer of the payload. The results of the optimization are presented in the article. The calculation of engine efficiency indicators was carried out on the basis of modeling the flight cycle of the helicopter, taking into account its aerodynamic characteristics. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine and simulation of the transport helicopter flight cycle is presented. The developed methods and models are implemented in the ASTRA program. It is shown that optimal parameters of the working process of a gas turbine engine with a free turbine and a recuperative heat exchanger depend significantly on the heat exchanger effectiveness. The possibility of increasing the efficiency of the engine due to heat regeneration is also shown.


Author(s):  
Mitsuru Hattori ◽  
Tsutomu Yamamoto ◽  
Keiichiro Watanabe ◽  
Masaaki Masuda

NGK Insulators, Ltd. (NGK) has undertaken the research and development on the fabrication processes of high-heat-resistant ceramic components for the CGT301, which is a 300kW recuperative industrial ceramic gas turbine engine. This program is under the New Sunshine Project, funded by the Ministry of International Trade and Industry (MITI), and has been guided by the Agency of Industrial Science & Technology (AIST) since 1988. The New Energy and Industrial Technology Development Organization (NEDO) is the main contractor. The fabrication techniques for ceramic components, such as turbine blades, turbine nozzles, combustor liners, gas-path parts, and heat exchanger elements, for the 1,200°C engine were developed by 1993. Development for the 1,350°C engine has been underway since 1994. The baseline conditions for fabricating of all ceramic components have been established. This paper reports on the development of ceramic gas turbine components, and the improved accuracies of their shapes as well as improved reliability from the results of the interim appraisal conducted in 1994.


1974 ◽  
Author(s):  
J. A. Ritchie ◽  
P. A. Phillips ◽  
M. C. S. Barnard

This paper describes the application of the ceramic regenerator to the British Leyland truck gas turbine. Aspects of mounting, driving and sealing the heat exchanger disk are covered with particular reference to the single disk version of the 2S/350/R engine.


Author(s):  
Takeshi Sakida ◽  
Shinya Tanaka ◽  
Takao Mikami ◽  
Masashi Tatsuzawa ◽  
Tomoki Taoka

The CGT301 ceramic gas turbine has been developed under a contract from NEDO as a part of the New Sunshine Program of MITI since 1988 to 1998. The CGT301 is a recuperated, single-shaft ceramic gas turbine. Ceramic parts are used in the hot section of the engine, such as turbine blades, nozzle vanes, combustion liners and so on. As a primary feature of this turbine, the rotors are composed of ceramic blades inserted into metallic disks (“hybrid rotor”) for the future applicability to the large gas turbine. The R & D program consists of three phases, the model metal gas turbine, the primary type ceramic gas turbine and the pilot ceramic gas turbine. The pilot ceramic gas turbine showed etable operation at TIT of 1,350°C. This paper presents the progress in the development of the pilot ceramic gas turbine of CGT301.


Author(s):  
Karleine M. Justice ◽  
Jeffrey S. Dalton ◽  
Ian Halliwell ◽  
Stephen Williamson

Recent improvements in technology have enabled the development of models capable of capturing performance interactions in the thermal management of air vehicle systems. Such system level models are required for better understanding of integration constraints and interactions, and are becoming increasingly important because of the need for tighter coupling between the components of thermal management systems. The study described here integrates current engine modeling capabilities with an improved, more comprehensive thermal management simulation. More specifically, the current effort evaluates the heat loads associated with the lubrication system of a gas turbine engine. The underlying engine model represents a mid-size, two-spool, subsonic transport engine. The architecture of the model is adaptable to other two-spool turbine engines and missions. Mobil Avrex S Turbo 256 engine oil is used as the lubrication medium. The model consists of five bearing heat loads. Within the engine flowpath, local temperatures and the appropriate rotational speeds are the only parameters pertinent to the heat load calculations. General assumptions have been made to simplify the representation of the lubrication system. Fuel properties into the heat exchanger are assumed. A gear box attached to the high-speed shaft operates both supply pump and scavenge pump and sends compressed air to the oil reservoir. Once the oil is distributed to the bearings, the scavenge pump collects and sends it through a filter and a fuel/oil heat exchanger before it is remixed with the contents of the reservoir. A MATLAB/Simulink modeling environment provides a general approach that may be applied to the thermal management of any engine. As a result of this approach, the new model serves as a starting point for a flexible architecture that can be modified as more detailed specifications or data are made available. In this paper, results from the simple model are compared to a more comprehensive tribology-based analysis. The results demonstrate its successful application to a typical mission, based on very limited data. In general, these results will allow system designers to conduct preliminary analyses and trade studies of gas turbine engine thermal management systems.


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