scholarly journals Passive instability control by a heat exchanger in a combustor with nonuniform temperature

2017 ◽  
Vol 9 (4) ◽  
pp. 380-393 ◽  
Author(s):  
Aswathy Surendran ◽  
Maria A Heckl
Keyword(s):  
Heat Exchanger ◽  
Perforated Plate ◽  
Heat Exchanger Tube ◽  
Perforated Plates ◽  
Thermoacoustic Instabilities ◽  
Bias Flow ◽  
Stability Maps ◽  
Unstable Combustion ◽  
Set Up ◽  
Exchanger Tube

Thermoacoustic instabilities, caused by the feedback between unsteady heat release and acoustic pressure perturbations, are characterised by large-amplitude pressure oscillations. These oscillations, if uncontrolled, pose a threat to the integrity of combustion systems. One strategy to mitigate them is by installing cavity-backed perforated plates with bias flow into the combustion chamber. In this study, we consider a generic combustor configuration: a one-dimentional tube (with open and/or closed ends) containing a compact heat source and a heat exchanger tube row. The idea is to use the heat exchanger tube row as a device (analogously to a cavity-backed perforated plate) to manipulate the downstream end condition. We simulate the row of heat exchanger tubes by a slit-plate with bias flow. We derive the characteristic equation for the complex eigenfrequencies of this set-up. From the growth rates (imaginary parts of the eigenfrequencies), we construct stability maps for various system parameter combinations. The results, obtained for the first two modes of the system, show that by varying the cavity length or the bias flow velocity through the slits, we can stabilise a previously unstable combustion system.

Rational Analysis of Heat-Exchanger Tube-Sheet Stresses

1956 ◽  
Vol 23 (3) ◽  
pp. 468-473
Author(s):  
Yi-Yuan Yu
Keyword(s):  
Heat Exchanger ◽  
Present Method ◽  
Maximum Stress ◽  
Perforated Plate ◽  
Tube Sheet ◽  
Heat Exchanger Tube ◽  
Rational Analysis ◽  
Side Pressure ◽  
Limiting Values ◽  
Exchanger Tube

Abstract The paper presents a rational method of analysis of heat-exchanger tube-sheet stresses. While the tube sheet is taken to be a perforated plate on an elastic foundation in the manner of Gardner and Miller, it is also considered as part of an integrated indeterminate structure, and the interaction between the tube sheet and the connecting cylindrical shells and flange of the exchanger is determined so that a condition may be formulated which the edge rotation and edge moment of the tube sheet must satisfy. In general, neither the edge rotation nor the edge moment is zero; the edge of a tube sheet is therefore neither clamped nor simply supported. Application of the present method to four different types of heat exchangers is described in detail. To illustrate the method, Gardner’s example of a fixed-tube-sheet exchanger is recalculated. While Gardner’s method yields only the two limiting values of the maximum stress in the tube sheet, which differ by more than 100 per cent, the present method makes it possible to determine the exact value of this maximum stress. By means of the present method, the stresses in the other parts of the heat exchanger, namely, the tubes, shell, head, and flange, also can be calculated. As a consequence of the present analysis, it is found that, in the external-floating-head type of exchanger, the tube-sheet stress is not independent of the shell-side pressure, which is contrary to Gardner’s and Miller’s conclusions.

The Plane-Stress Problem of Perforated Plates

1952 ◽  
Vol 19 (3) ◽  
pp. 355-360
Author(s):  
G. Horvay
Keyword(s):  
Heat Exchanger ◽  
Stress Distribution ◽  
Plane Stress ◽  
Elastic Moduli ◽  
Heat Exchanger Tube ◽  
Perforated Plates ◽  
Stress Problem ◽  
Plane Stress Problem ◽  
Exchanger Tube

Abstract In an earlier paper it was indicated that perforated plates of triangular layout, with narrow ligaments, as they occur, for instance, in heat-exchanger tube sheets, can be treated in plane-stress calculations as solid sheets of suitable elastic moduli, provided that the stress distribution does not vary appreciably from hole to hole. This paper completes that study by providing suitable curves (Figs. 4, 8), from which deformations and stresses can be read off in terms of the values calculated for solid sheets, for mechanical, thermal, and gravitational loads.

Design of Perforated Plates

1962 ◽  
Vol 84 (3) ◽  
pp. 307-319 ◽  
Author(s):  
W. J. O’Donnell ◽  
B. F. Langer
Keyword(s):  
Heat Exchanger ◽  
Elastic Constants ◽  
Thermal Stresses ◽  
Heat Exchanger Tube ◽  
Perforated Plates ◽  
Strain Measurements ◽  
Effective Elastic Constants ◽  
Theoretical Considerations ◽  
Exchanger Tube

This paper describes a method for calculating stresses and deflections in perforated plates with a triangular penetration pattern. The method is based partly on theory and partly on experiment. Average ligament stresses are obtained from purely theoretical considerations but effective elastic constants and peak stresses are derived from strain measurements and photoelastic tests. Acceptable limits for pressure stresses and thermal stresses in heat exchanger tube sheets are also proposed.

Research of a heat exchanger tube durability of a phase transition accumulator, working in the composition of NPP

2019 ◽  
Vol 54 (1) ◽  
pp. 63-71
Author(s):  
V.E. Yurin ◽  
◽  
A.B. Moskalenko ◽  
M.A. Murtazov ◽  
◽  
...  
Keyword(s):  
Phase Transition ◽  
Heat Exchanger ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Recent Design Technologies of Moisture Separator Reheater

2009 ◽  
Author(s):  
Jun Manabe ◽  
Jiro Kasahara ◽  
Toshiki Kojima ◽  
Issaku Fujita
Keyword(s):  
Heat Exchanger ◽  
Nuclear Power ◽  
Tube Bundle ◽  
Current Model ◽  
Temperature Oscillation ◽  
Separation Performance ◽  
Heat Exchanger Tube ◽  
Water Test ◽  
Moisture Separator ◽  
Exchanger Tube

This paper introduces the development of the current model Moisture Separator Reheater (MSR) for nuclear power plant (NPP) turbines, commercially placed in service in the period 1984–1997, focusing on the mist separation performance of the MSR along with drainage from heat exchanger tubes. A method of predicting the mist separation performance was devised first based on the observation of mist separation behaviors under an air-water test, then developed for the application to predict under the steam conditions, followed by the verification in comparison with the actual results of a steam condition test. The instability of tube drainage associated with both sub-cooling and temperature oscillation, which may adversely affect the seal welding of tubes to tube sheet owing to thermal fatigue, was measured on an existing unit both to clarify the behaviors and to develop a method to suppress them. Both methods were applied to current model MSR and the effectiveness of the methods was demonstrated. A new concept MSR for 1,700 MW class APWR units is put in perspective based on the technologies, alongside a multidisciplinary optimum design evaluating the heat exchanger tube bundle.

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