Effects of Partial Cooling on Tightness of Heat Exchanger Girth Flange

2017 ◽  
Author(s):  
Kyohei Takahashi ◽  
Toshikazu Miyashita ◽  
Shunji Kataoka ◽  
Yoshiaki Uno ◽  
Takuya Sato
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Temperature Distribution ◽  
Contact Pressure ◽  
Heat Exchangers ◽  
Liquid Level ◽  
Design Codes ◽  
Key Characteristics ◽  
Present Design

For the girth flange of heat exchangers, the circumferential temperature distribution of shell and connecting flange due to inside fluid will affect tightness of the girth flange, however this effect is not considered in present design codes. It is important to know the key characteristics of flange tightness to minimize the risk of leakage. In past studies, the effects of circumferential temperature distribution on flange tightness were investigated at high temperature operations. The effects of partial cooling on flange tightness might be severer than circumferential high temperature distribution. In this paper, the effects of partial cooling on flange tightness were studied. The flange tightness was evaluated by wideness of partially cooled region (liquid level) of heat exchanger and gasket recovery characteristics parametrically. Based on these studies, it was concluded that the gasket contact pressure was decreased by the partial cooling of heat exchanger and the effects of the above mentioned factors were summarized quantitatively.

Performance Optimization of Compact Ceramic High Temperature Heat Exchangers

2007 ◽  
Author(s):  
Q. Y. Chen ◽  
M. Zeng ◽  
D. H. Zhang ◽  
Q. W. Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Performance Optimization ◽  
Heat Exchangers ◽  
Radiation Heat Transfer ◽  
Surface Radiation ◽  
Radiation Heat ◽  
High Temperature Side ◽  
Temperature Heat

In the present paper, the compact ceramic high temperature heat exchangers with parallel offset strip fins and inclined strip fins (inclined angle β = 0∼70°) are investigated with CFD method. The numerical simulations are carried out for high temperature (1500°C), without and with radiation heat transfer, and the periodic boundary is used in transverse direction. The fluid of high temperature side is the standard flue gas. The material of heat exchanger is SiC. NuS-G.R(with surface and gaseous radiation heat transfer) is averagely higher than NuNo.R (without radiation heat transfer) by 7% and fS-G.R is averagely higher than fNo.R by 5%. NuS-G.R(with surface and gaseous radiation heat transfer) is averagely higher than NuS.R (with only surface radiation heat transfer) by 0.8% and fS-G.R is averagely higher than fS.R by 3%. The thermal properties have significantly influence on the heat transfer and pressure drop characteristics, respectively. The heat transfer performance of the ceramic heat exchanger with inclined fins (β = 30°) is the best.

Viability of Ceramic High Temperature Heat Exchangers in NGNP Applications

2008 ◽  
Author(s):  
Merrill A. Wilson ◽  
Charles Lewinsohn ◽  
James Cutts ◽  
Yitung Chen ◽  
Valery Ponyavin
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Ceramic Materials ◽  
Reliability Models ◽  
Tube Heat Exchanger ◽  
Temperature Heat ◽  
Intermediate Heat Exchanger ◽  
Recent Developments ◽  
Higher Temperature

The recent developments in the energy industry have kindled renewed interest in producing energy more efficiently. This has motivated the development of higher temperature cycles and their associated equipment. In this paper we will discuss several design configurations coupled with the inherent properties of preferred ceramic materials to assess the viability and design reliability of ceramic heat exchangers for next generation high temperature heat exchangers. These analyses have been extended to conceptually compare the traditional shell and tube heat exchanger with shell and plate heat exchangers. These analyses include hydrodynamic, heat transfer, mechanical stress and reliability models applicable to an Intermediate Heat Exchanger (IHX) and Process Coupling Heat Exchangers. It was found that ceramic micro-channel heat exchanger designs proved to have the greatest reliability due to their inherent mechanical properties, minimal thermo-mechanical stresses while improving the performance efficiency in a compact footprint.

Performance Analysis and Optimal Design of Heat Exchangers Used in a High Temperature and High Pressure System

2008 ◽  
Author(s):  
Byoung Ik Choi ◽  
Kui Soon Kim ◽  
Man Yeong Ha ◽  
Ji Hwan Jeong ◽  
Jong Rae Cho ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Heat Exchanger ◽  
Optimal Design ◽  
Heat Exchangers ◽  
Pressure Loss ◽  
Pressure System ◽  
High Pressure System ◽  
Flow Type ◽  
Design Variables

A computational study for the optimal design of heat exchangers used in a high temperature and high pressure system is presented. Two types of air to air heat exchangers are considered in this study. One is a single-pass cross-flow type with straight plain tubes and the other is a two-pass cross-counter flow type with plain U-tubes. These two types of heat exchangers have the staggered arrangement of tubes. The design models are formulated using the number of transfer units (ε-NTU method) and optimized using a genetic algorithm. In order to design compact light weight heat exchangers with the minimum pressure loss and the maximum heat exchange rate, the weight of heat exchanger core is chosen as the object function. Dimensions and tube pitch ratio of a heat exchanger are used as design variables. Demanded performance such as the pressure loss (ΔP) and the temperature drop (ΔP) are used as constraints. The performance of heat exchangers is discussed and their optimal designs are presented with an investigation of the effect of design variables and constraints.

Numerical Simulation Study on Local Enhanced Heat Transfer for High Temperature Heat Pipe Heat Exchanger

2011 ◽  
Vol 396-398 ◽  
pp. 897-903
Author(s):  
Shi Mei Sun ◽  
Jing Min Zhou
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Temperature Distribution ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Fluid Temperature ◽  
Temperature Heat ◽  
High Temperature Heat Pipe ◽  
Pipe Heat

A High Temperature Heat Pipe Heat Exchanger Consists of Heat Pipes Filled with Different Working Media inside. in Different Temperature Zones, Heat Pipes with Different Working Media Are Linked Safely by Controlling the Vapor Temperature, the Media inside the Heat Pipe. the Vapor Temperature inside the Pipe Is Heavily Affected by the Temperature Field of Fluid outside the Heat Pipes and the Heat Transfer Performance inside the Heat Pipe, while the Heat Transfer Performance inside the Pipe in Turn Has a Bearing on the Temperature Distribution of Fluid outside the Pipe. to Coordinate the Fluid Temperature Distribution both inside and outside the Pipes, Study on Local Heat Transfer Enhancement Has Been Conducted on High Temperature Heat Pipe Heat Exchanger in this Article, and Cfd Computational Software Was Used to Make Rational and Accurate Prediction of Fluid Temperature Distribution both inside and outside the Pipes, so as to Provide Economic and Reliable Design Basis for High Temperature Heat Pipe Heat Exchanger.

Developing Corrosion-Resistant Joints Applied in the Plate Heat Exchanger

2011 ◽  
Vol 410 ◽  
pp. 191-195
Author(s):  
C.H. Shu ◽  
H.W. Hsu ◽  
T.Y. Yeh ◽  
W.S. Chen ◽  
R.K. Shiue
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Industrial Applications ◽  
Plate Heat Exchanger ◽  
Corrosion Resistant ◽  
Plate Heat ◽  
316 Stainless Steel

The manufacturing of plate heat exchangers is much more difficult than that of making traditional heat exchangers. The demand of increased corrosion resistance, avoiding Cu ion contamination, resisting to high-temperature resulting from various applied environments makes the traditional Cu brazed 316 stainless steel (316SS) plate heat exchanger fail to satisfy certain applications. Corrosion-resistant brazed 316SS plate heat exchangers are successfully developed using two commercially available Ni-based brazing foils, and they are valuable for industrial applications.

Roller Profiling for Shaping Corrugated Profiles on the Heat Exchanger Tape for Wind Tunnels

2021 ◽  
pp. 16-27
Author(s):  
Yu.V. Shchipkova ◽  
A.Yu. Popov
Keyword(s):  
Plastic Deformation ◽  
Heat Exchanger ◽  
Contact Pressure ◽  
Heat Exchangers ◽  
Wind Tunnels ◽  
Regenerative Heat ◽  
Elastic Aftereffect ◽  
Study Results ◽  
Profile Correction ◽  
Profiling Techniques

The efficiency of regenerative heat exchangers with heat-accumulating nozzles made of rolled corrugated tapes depends on the profile of their corrugation. It is technologically difficult to obtain corrugations of a given shape by copying --- stamping. It is technically more expedientto form such a profile by rolling between two rollers. The contact area is smaller, and the contact pressure is significantly higher. In this case, the shape and accuracy of the tape profile are determined by the accuracy of calculation and manufacturing of the profile of the rollers. The length of the profiling zone and the contact pressure depend on the diameter of the rollers. To apply the known profiling techniques when calculating the corrugated profile of the rollers, it is necessary to find the position of the centroid. However, the difficulty is in the tape between the rollers whose thickness cannot be neglected. Therefore, the problem is solved by rolling the roller and the rail smooth, where the tape with a profile formed on it is considered as a rail. The paper introduces a technique of roller profiling taking into account the above factors. When profiling the rollers, the springing of the tape, i.e., elastic aftereffect of plastic deformation, is taken into account. The suitable diameter of the rollers has been determined. The study results in a method developed for calculating the rollers corrugation profile, taking into account the established parameters, i.e., diameters of the centroids and rollers, and the rollers teeth profile correction value, depending on the tape springing during rolling

Design and Development of a Low-Cost, High Temperature Silicon Carbide Micro-Channel Recuperator

2005 ◽  
Author(s):  
Merrill A. Wilson ◽  
Kurt Recknagle ◽  
Kriston Brooks
Keyword(s):  
Heat Transfer ◽  
Silicon Carbide ◽  
High Temperature ◽  
Heat Exchanger ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Ceramic Materials ◽  
Micro Channel ◽  
Micro Channels ◽  
Micro Turbine

Typically, ceramic micro-channel devices are used for high temperature heat exchangers, catalytic reactors, electronics cooling, and processing of corrosive streams where the thermomechanical benefits of ceramic materials are desired. These benefits include: high temperature mechanical and corrosion properties and tailorable material properties such as thermal expansion, electrical conductivity and thermal conductivity. In addition, by utilizing Laminated Object Manufacturing (LOM) methods, inexpensive ceramic materials can be layered, featured and laminated in the green state and co-sintered to form monolithic structures amenable to mass production. In cooperation with the DOE and Pacific Northwest National Labs, silicon carbide (SiC) based micro-channel recuperator concepts are being developed and tested. The performance benefits of a high temperature, micro-channel heat exchanger are realized from the improved thermal efficiency of the high temperature cycles and the improved effectiveness of micro-channels for heat transfer. In designing these structures, the heat and mass transfer within the micro-channels are being analyzed with heat transfer models, computational fluid dynamics models and validated with experimental results. As an example, a typical micro-turbine cycle was modified and modeled to incorporate this ceramic recuperator and it was found that the overall thermal efficiency of the micro-turbine could be improved from about 27% to over 40%. Process improvements require technical advantages and cost advantages. These LOM methodologies have been based on well-proven industry standard processes where labor, throughput and capital estimates have been tested. Following these cost models and validation at the prototype scale, cost estimates were obtained. For the micro-turbine example, cost estimates indicate that the high-temperature SiC recuperator would cost about $200 per kWe. The development of these heat exchangers is multi-faceted and this paper focuses on the design optimization of a layered micro-channel heat exchanger, its performance testing, and fabrication development through LOM methodologies.

High Temperature Heat Exchangers (HTHX) for Nuclear Applications

2006 ◽  
Author(s):  
James C. Govern ◽  
Cila V. Herman ◽  
Dennis C. Nagle
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Operating Conditions ◽  
Heat Exchanger Design ◽  
Performance Requirements ◽  
Starting Point ◽  
Temperature Heat ◽  
And Performance ◽  
Design Challenges

Many nuclear engineering applications, current and future, require heat exchangers operating at high temperatures. The operating conditions and performance requirements of these heat exchangers present special design challenges. This paper considers these challenges with respect to a simple heat exchanger design manufactured of a novel carbon material. Heat transfer and effectiveness calculations are performed for several parametric studies regarding heat exchanger parameters. These results are used to better understand the design challenges of high temperature heat exchangers as well as provide a starting point for future optimization work on more complex heat exchanger designs.

High-Temperature, Coal-Fired Combustor With Ceramic Heat Exchangers for CCGT Systems

1980 ◽  
Author(s):  
H. W. Carpenter ◽  
J. Campbell ◽  
L. H. Russell ◽  
D. E. Wright
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
Heat Exchangers ◽  
Working Fluid

High-temperature, coal-fired combustors with ceramic heat exchangers were designed for CCGT systems. The objective in evaluating CCGT systems is to convert U.S. coal to electricity with higher efficiency. Higher temperatures are required to accomplish this goal and ceramic heat exchanger surfaces allow the use of working fluid temperatures to 2500 F and higher. The results of a comprehensive government study are described in which an atmospheric fluidized bed and cyclone fired combustor/heat exchanger were designed for operation at 1750 and 2250 F.

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