INVESTIGATE ADVANCED HEAT EXCHANGER DESIGNS OF COMPACT HEAT EXCHANGERS WHEN OPERATING IN A MARINE ENVIRONMENT

1966 ◽  
Author(s):  
Henry H. Osborn
Keyword(s):  
Heat Exchanger ◽  
Marine Environment ◽  
Heat Exchangers ◽  
Compact Heat Exchangers

A Heuristic for Designing Hybrid Compact Heat Exchangers for Nuclear Applications

2021 ◽  
Author(s):  
Venkata Rajesh Saranam ◽  
Peter Carter ◽  
Kyle Rozman ◽  
Ömer Dogan ◽  
Brian K. Paul
Keyword(s):  
Heat Exchanger ◽  
Diffusion Bonding ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
Nuclear Industry ◽  
Compact Heat Exchangers ◽  
Bonding Parameters ◽  
Heat Exchanger Design ◽  
Creep Fatigue ◽  
Gen Iv

Abstract Hybrid compact heat exchangers (HCHEs) are a potential source of innovation for intermediate heat exchangers in nuclear industry, with HCHEs being designed for Gen-IV nuclear power applications. Compact heat exchangers are commonly fabricated using diffusion bonding, which can provide challenges for HCHEs due to resultant non-uniform stress distributions across hybrid structures during bonding, leading to variations in joint properties that can compromise performance and safety. In this paper, we introduce and evaluate a heuristic for determining whether a feasible set of diffusion bonding conditions exist for producing HCHE designs capable of meeting regulatory requirements under nuclear boiler and pressure vessel codes. A diffusion bonding model for predicting pore elimination and structural analyses are used to inform the heuristic and a heat exchanger design for 316 stainless steel is used to evaluate the efficacy of the heuristic to develop acceptable diffusion bonding parameters. A set of diffusion bonding conditions were identified and validated experimentally by producing various test coupons for evaluating bond strength, ductility, porosity, grain size, creep rupture, creep fatigue and channel deviation. A five-layer hybrid compact heat exchanger structure was fabricated and tensile tested demonstrating that the bonding parameters satisfy all criteria in this paper for diffusion bonding HCHEs with application to the nuclear industry.

Numerical Investigation on the Characteristic of the Reverse Flow Phenomenon in a Z-Type Parallel Compact Heat Exchanger With Large Number of Tubes

2018 ◽  
Author(s):  
Jian Zhou ◽  
Ming Ding ◽  
Haozhi Bian ◽  
Yinxing Zhang ◽  
Zhongning Sun
Keyword(s):  
Heat Exchanger ◽  
Pressure Distribution ◽  
Coming Out ◽  
Heat Exchangers ◽  
Cooling System ◽  
Reverse Flow ◽  
Flow Distribution ◽  
Flow Phenomenon ◽  
Compact Heat Exchangers ◽  
Geometry Design

The parallel compact heat exchangers have been widely applied in the various fields such as heat exchangers in chemical engineering, the solar collector, fuel cells and the passive removal heat exchanger in passive containment cooling system (PCCS), etc. The heat exchangers in the PCCS removes out the heat brought by the steam coming out from the broken reactor or primary cooling system. Therefore, the performance of the passive containment cooling system heat exchanger (PCCS HX) will greatly influence the safety and integrity of the containment. In previous investigations on the parallel compact heat exchangers, attentions are focused on the pressure distribution and flow distribution in the heat exchangers. A bad flow distribution in the heat exchanger will reduce the heat performance. More seriously, the coolant in some tubes may boils and the tubes will be overheated, resulting in explosion of tubes. Therefore, the characteristic of pressure distribution and the flow distribution should be investigated for a uniform flow distribution. In the past studies of the compact heat exchangers, the numbers of tube are almost under 72 which is relatively small, while the number of tubes PCCS HX is usually over than 100. And the pressure distribution in compact heat exchangers is assumed that the pressure recovery plays a leading role. However, the more numbers of tube will bring more flow maldistribution, if the geometry design is selected inappropriately. The reverse flow may occur in the heat exchanger, which means that in some tubes, the coolant flows from the tube outlet to the inlet. This phenomenon of reverse flow have never been mentioned in previous studies. The occurrence of the reverse flow will significantly decrease the performance of the heat exchanger and cause a bad influence on the safety of the containment. In the PCCS, the Z-type heat exchanger is one of the choice of PCCS HX (heat exchanger) design. Therefore, the present study focus on the characteristic of reverse flow phenomenon in Z-type heat exchangers. The pressure distribution and the flow distribution have been separately investigated deeply. The conclusion of this study will provide a guide to the geometry design of the PCCS HX with large number of tubes.

A Survey of Important Auxiliary Equations for Selected Compact Heat Exchanger

2005 ◽  
Author(s):  
Richard G. Carranza
Keyword(s):  
Heat Exchanger ◽  
Surface Area ◽  
Heat Exchangers ◽  
Volume Ratio ◽  
Compact Heat Exchanger ◽  
Fin Efficiency ◽  
Compact Heat Exchangers ◽  
Central Location

Important auxiliary equations are presented that are typically used in compact heat exchanger research. These relationships are presented only for selected compact heat exchangers — bare pipe, helically finned pipe, plate finned pipe, spined pipe, and plate exchangers. The equations primarily address issues relating to heat exchanger geometry, surface area to volume ratio, and fin efficiency. Furthermore, they are organized in a systematic manner and consolidated in one central location for easy reference.

Comparison of Plate Fin Compact Heat Exchanger Performance

2008 ◽  
Author(s):  
Ibrahim Khalil ◽  
Ahmad Abu Heiba ◽  
Robert Boehm
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Compact Heat Exchanger ◽  
Pumping Power ◽  
Compact Heat Exchangers ◽  
Advantages And Disadvantages ◽  
Low Weight ◽  
Full Explanation ◽  
Main Target ◽  
Large Heat

Plate fin heat exchangers (PFHE) are characterized by very close temperature approaches and high thermal effectiveness, large heat transfer area per unit volume, low weight per unit transfer and possibility of heat exchange between many process streams. These advantages are only limited by operating fluid temperatures and pressures. The main target of this paper is to study the performance of plate fin compact heat exchangers and to provide full explanation of previous comparison methods of compact heat exchanger surfaces (plain, strip, louvered, wavy, pin, perforated and vortex) used in plate fin compact heat exchangers. We generalize these methods to identify the advantages and disadvantages of each type of geometry (more than sixty geometries studied) based on required size, entropy generation, pumping power, weight, and cost. The effect of using different surfaces on each side of the heat exchanger and design recommendations are also discussed.

Experimental and Numerical Analyses of Friction Factors in Offset Strip Fin Heat Exchangers

2007 ◽  
Author(s):  
Aihua Wang ◽  
Samir F. Moujaes ◽  
Yitung Chen ◽  
Valery Ponyavin
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Experimental Measurements ◽  
Test Rig ◽  
Compact Heat Exchangers ◽  
Friction Factors ◽  
Offset Strip Fin

Heat transfer in compact heat exchangers is augmented by the introduction of the offset strip fins. With the breakdown of the thermal and hydro boundary layers to boost heat transfer, the fins increase the friction power. Two heat exchangers of different fin geometries structures were built and tested. The results of the study show that the round-edge-fin heat exchanger has the smaller friction factor. A test rig was constructed to measure the friction factor of the offset strip fin heat exchangers with air. A modified hydraulic diameter was used to calculate the main parameters. The computational fluid dynamics package FLUENT was used to predict the flow in the heat exchanger. The numerical investigation was conducted and compared with experimental measurements.

Fluid Flow and Heat Transfer at Micro- and Meso-Scales With Application to Heat Exchanger Design

2000 ◽  
Vol 53 (7) ◽  
pp. 175-193 ◽  
Author(s):  
S. S. Mehendale ◽  
A. M. Jacobi ◽  
R. K. Shah
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Thermal Systems ◽  
Structured Surfaces ◽  
Compact Heat Exchangers ◽  
Heat Exchanger Design ◽  
Flow And Heat Transfer ◽  
The Status ◽  
Material Volume ◽  
Modern Technologies

By their very nature, compact heat exchangers allow an efficient use of material, volume, and energy in thermal systems. These benefits have driven heat exchanger design toward higher compactness, and the trend toward ultra-compact designs will continue. Highly compact surfaces can be manufactured using micro-machining and other modern technologies. In this paper, unresolved thermal-hydraulic issues related to ultra-compact designs are discussed, and the status of the technologies required for the production of ultra-compact structured surfaces is summarized. This review article includes 67 references.

Heat Exchanger Development for Compact Water/LiBr Sorption Systems

2006 ◽  
Author(s):  
E. Estiot ◽  
S. Natzer ◽  
M. Harm ◽  
C. Kren ◽  
S. Schweigler
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Lithium Bromide ◽  
Heat Pumps ◽  
Vapor Flow ◽  
Compact Heat Exchangers ◽  
Residential Heating ◽  
Hydraulic Conditions ◽  
Falling Film Absorption ◽  
Absorption Cycle

For energy efficient tri-generation, solar cooling or residential heating compact sorption appliances using the working pair water/lithium bromide (LiBr) can be applied. Standard plant technology established in the field of large capacity chillers and heat pumps with conventional tube-and-shell configuration cannot be easily adapted to compact units for economic and operational reasons. For a successful marketing of compact sorption units, major effort is required to achieve tolerable plant dimensions and weight together with affordable first cost and reliable operation. In a research project, the design of all key components, i.e. main heat exchangers - evaporator, absorber, condenser and generator - and the liquid pumps for refrigerant and absorbent solution has been revised. In order to achieve uncomplicated manufacturing and improved vacuum tightness, concepts for standardized heat exchanger modules have been developed. A single effect absorption plant has been erected for the experimental investigation of the newly designed finned heat exchangers and plate heat exchanger configurations as main heat exchangers in an absorption cycle. Concepts for sizing these compact heat exchanger units in compliance with the given thermo-hydraulic conditions of a water/lithium bromide absorption cycle will be presented. Estimations of the wetting of the heat exchangers, the pressure drop in the vapor flow, as well as the achieved heat transfer per heat exchanger volume will be discussed. Experimental results for falling film absorption with compact heat exchangers will be presented.

scholarly journals NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

2008 ◽  
Author(s):  
Piyush Sabharwall ◽  
Mike Patterson ◽  
Vivek Utgikar ◽  
Fred Gunnerson
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Pressure Drop ◽  
Liquid Metal ◽  
Phase Change ◽  
Heat Exchangers ◽  
Liquid Metals ◽  
Compact Heat Exchangers ◽  
Process Heat

One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor-process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rationale for considering liquid metals as the working fluid is because of the higher convective heat transfer coefficient. This explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet of NGNP and inlet of the process heat facility. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change heat exchanger with Na as the heat exchanger coolant. In order to design a very efficient and effective heat exchanger one must optimize the design such that we have a high heat transfer and a lower pressure drop, but there is always a tradeoff between them. Based on NGNP operational parameters, a heat exchanger analysis with the sodium phase change is presented to show that the heat exchanger has the potential for highly effective heat transfer, within a small volume at reasonable cost.

Air Cooled Compact Heat Exchanger Design for Avionics Thermal Management Using Published Test Data

2003 ◽  
Author(s):  
George Hall ◽  
James Marthinuss
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Thermal Management ◽  
Test Data ◽  
Heat Exchangers ◽  
Optimized Design ◽  
Compact Heat Exchanger ◽  
Compact Heat Exchangers ◽  
Heat Exchanger Design

This paper will discuss air-cooled compact heat exchanger design using published data. Kays & London’s “Compact Heat Exchangers” [1] contains measured heat transfer and pressure drop data on a variety of circular and rectangular passages including circular tubes, tube banks, straight fins, louvered fins, strip or lanced offset fins, wavy fins and pin fins. While “Compact Heat Exchangers” is the benchmark for air cooled heat exchanger test data it makes no attempt to summarize the results or steer the thermal designer to an optimized design based on the different factors or combination of heat transfer, pressure drop, size, weight, or even cost. Using this reduced data and the analytical solutions provided highly efficient compact heat exchangers could be designed. This paper will guide a thermal engineer toward this optimized design without having to run trade studies on every possible heat exchanger design configuration. Typical applications of published fin data in the aerospace and military electronics include electronics cold plates, card rack walls and air-to-air heat exchangers using fan driven and ECS driven air. Airborne electronics often require extremely dense packaging techniques to fit all the required functions into the available volume. While leaving little room for cooling hardware this also drives power densities up to levels (20 W/sq-cm) that require highly efficient heat transfer techniques. Several design issues are discussed including pressure drop, heat transfer, compactness, axial conduction, flow distribution and passage irregularities (bosses). Comparisons between fin performance are made and conclusions are drawn about the applicability of each type of fin to avionics thermal management.

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