Estimation of Thermal and Hydraulic Characteristics of Compact Brazed Plate Heat Exchangers
(2013)- Abstract
- This thesis work presents various performance estimation methods of compact brazed plate
heat exchangers (BPHE) operating in single phase, condenser, evaporator, cascaded and
transcritical applications. Such methods play a vital role in development of heat exchanger
selection software and during geometry parameter estimation in the new product development
process.
The suitability of employing commercial computational fluid dynamics (CFD) codes for
estimating single phase thermal and hydraulic performance is investigated. Parametric studies
are conducted on geometries of single phase fluid sections to isolate and quantify the
influence of individual geometric... (More) - This thesis work presents various performance estimation methods of compact brazed plate
heat exchangers (BPHE) operating in single phase, condenser, evaporator, cascaded and
transcritical applications. Such methods play a vital role in development of heat exchanger
selection software and during geometry parameter estimation in the new product development
process.
The suitability of employing commercial computational fluid dynamics (CFD) codes for
estimating single phase thermal and hydraulic performance is investigated. Parametric studies
are conducted on geometries of single phase fluid sections to isolate and quantify the
influence of individual geometric parameters. The influence of mesh characteristics, choice of
boundary conditions and turbulent flow modeling on the accuracy of the thermal and
hydraulic predictions is presented. Benefits of simulation of fluid flow in entire channels and
characteristics of channel flow for different geometric patterns are also presented.
A computationally light, general, robust and continuous rating calculation method is
developed for implementation in BPHE selection software. The pressure-enthalpy based
method provides a generic rating core for various types of applications and provides extensive
post processing information of the heat transfer process. General single phase thermal and
hydraulic empirical correlations are developed as functions of plate geometric parameters.
For facilitating better integration of the developed calculation method with other refrigeration
system simulation software, first or higher order continuity is maintained in the sub-routines
used for calculating local heat transfer coefficients and refrigerant properties. A new finite
grid interpolation method is developed for fast and accurate retrieval of refrigerant properties.
The developed method is currently implemented in SSPG7 (BPHE selection software of
SWEP International AB) for supporting transcritical CO2 calculations and cascaded heat
exchanger calculations.
Additionally, the methods developed for single phase and two phase test data evaluation
based on meta-heuristic optimization routines is also presented. The application and results of
using the developed rating models for various types of calculations is summarized. Other
topics such as influence of variable fluid properties on BPHE rating calculations, influence of
multi-pass flow arrangement on lumped BPHE rating calculations are briefly presented. (Less) - Abstract (Swedish)
- Popular Abstract in Swedish
Lödda kompakta plattvärmeväxlare används i stor utsträckning i kyl – och värmepumpanläggningar samt luftkonditioneringsanläggningar.
Såväl enfasvärmeutbyte, dvs värmeutbyte mellan två vätskor, som fasomvandling genom kondensation och förångning är viktiga
tillämpningsområden. Apparaterna användes inom industri, hushåll, samhälleliga inrättningar mm.
Prestandan för olika plattvärmeväxlare har traditionellt bestämts genom experimentella undersökningar av värmeöverföring och tryckfall i
speciella testriggar eller laboratorier hos de tillverkande företagen.
För att göra ingenjörsarbetet med produktutveckling, design samt test av innovativa idéer effektivt... (More) - Popular Abstract in Swedish
Lödda kompakta plattvärmeväxlare används i stor utsträckning i kyl – och värmepumpanläggningar samt luftkonditioneringsanläggningar.
Såväl enfasvärmeutbyte, dvs värmeutbyte mellan två vätskor, som fasomvandling genom kondensation och förångning är viktiga
tillämpningsområden. Apparaterna användes inom industri, hushåll, samhälleliga inrättningar mm.
Prestandan för olika plattvärmeväxlare har traditionellt bestämts genom experimentella undersökningar av värmeöverföring och tryckfall i
speciella testriggar eller laboratorier hos de tillverkande företagen.
För att göra ingenjörsarbetet med produktutveckling, design samt test av innovativa idéer effektivt krävs datorbaserade beräkningsmetoder av
olika slag. Vijayas avhandling handlar i huvudsak om detta och han har utvecklat beräkningsverktyg och beräkningsmetoder som är
tillämpbara för dessa ändamål.
Användningen av avancerade och moderna beräkningsmetoder (CFD) baserade på lösning av partiella differentialekvationer (vilka
matematiskt beskriver värmeöverföringen och strömningen) utvärderas ingående genom studier av inverkan av ett flertal parametrar såsom
turbulensmodeller, randvillkor och geometrisk upplösning mm. Rekommendationer fastläggs.
En robust enklare metodik för prestandaberäkning har utvecklats för valet av lödd plattvärmeväxlare. Tryck-entalpi metoden utgör grunden.
För att möjliggöra att den utvecklade metodiken kan integreras med andra simuleringsverktyg har speciella subrutiner utvecklats för
beräkning av värmeövergångskoefficienter och köldmediers termiska egenskaper.
Metoder har också utvecklats för utvärdering av experimentella mätningar för såväl enfas som fasomvandlingsprocesser.
Noggrannhetsaspekter i olika metoder för uppskattning av termiska prestanda ventileras också. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3799250
- author
- Gullapalli, Vijaya Sekhar LU
- supervisor
-
- Bengt Sundén LU
- opponent
-
- Dr Wadekar, Vishwas, Aspen Technology, Great Britain
- organization
- publishing date
- 2013
- type
- Thesis
- publication status
- published
- subject
- keywords
- Brazed plate heat exchangers, CFD, heat transfer, pressure drop, heat exchanger selection software, transcritical-CO2 calculations, heat exchanger rating, evaporation, condensation, refrigerant properties, discretized calculations
- pages
- 156 pages
- publisher
- Department of Energy Sciences, Lund University
- defense location
- Room E:B, in the E-building, Ole Römers väg 3, Lund University Faculty of Engineering
- defense date
- 2013-06-13 13:15:00
- ISBN
- 978-91-7473-565-9
- language
- English
- LU publication?
- yes
- id
- e881a11f-f55d-479f-bb39-efb462c120ec (old id 3799250)
- date added to LUP
- 2016-04-04 11:37:44
- date last changed
- 2018-11-21 21:06:07
@phdthesis{e881a11f-f55d-479f-bb39-efb462c120ec, abstract = {{This thesis work presents various performance estimation methods of compact brazed plate<br/><br> heat exchangers (BPHE) operating in single phase, condenser, evaporator, cascaded and<br/><br> transcritical applications. Such methods play a vital role in development of heat exchanger<br/><br> selection software and during geometry parameter estimation in the new product development<br/><br> process.<br/><br> The suitability of employing commercial computational fluid dynamics (CFD) codes for<br/><br> estimating single phase thermal and hydraulic performance is investigated. Parametric studies<br/><br> are conducted on geometries of single phase fluid sections to isolate and quantify the<br/><br> influence of individual geometric parameters. The influence of mesh characteristics, choice of<br/><br> boundary conditions and turbulent flow modeling on the accuracy of the thermal and<br/><br> hydraulic predictions is presented. Benefits of simulation of fluid flow in entire channels and<br/><br> characteristics of channel flow for different geometric patterns are also presented.<br/><br> A computationally light, general, robust and continuous rating calculation method is<br/><br> developed for implementation in BPHE selection software. The pressure-enthalpy based<br/><br> method provides a generic rating core for various types of applications and provides extensive<br/><br> post processing information of the heat transfer process. General single phase thermal and<br/><br> hydraulic empirical correlations are developed as functions of plate geometric parameters.<br/><br> For facilitating better integration of the developed calculation method with other refrigeration<br/><br> system simulation software, first or higher order continuity is maintained in the sub-routines<br/><br> used for calculating local heat transfer coefficients and refrigerant properties. A new finite<br/><br> grid interpolation method is developed for fast and accurate retrieval of refrigerant properties.<br/><br> The developed method is currently implemented in SSPG7 (BPHE selection software of<br/><br> SWEP International AB) for supporting transcritical CO2 calculations and cascaded heat<br/><br> exchanger calculations.<br/><br> Additionally, the methods developed for single phase and two phase test data evaluation<br/><br> based on meta-heuristic optimization routines is also presented. The application and results of<br/><br> using the developed rating models for various types of calculations is summarized. Other<br/><br> topics such as influence of variable fluid properties on BPHE rating calculations, influence of<br/><br> multi-pass flow arrangement on lumped BPHE rating calculations are briefly presented.}}, author = {{Gullapalli, Vijaya Sekhar}}, isbn = {{978-91-7473-565-9}}, keywords = {{Brazed plate heat exchangers; CFD; heat transfer; pressure drop; heat exchanger selection software; transcritical-CO2 calculations; heat exchanger rating; evaporation; condensation; refrigerant properties; discretized calculations}}, language = {{eng}}, publisher = {{Department of Energy Sciences, Lund University}}, school = {{Lund University}}, title = {{Estimation of Thermal and Hydraulic Characteristics of Compact Brazed Plate Heat Exchangers}}, url = {{https://lup.lub.lu.se/search/files/5818132/3799358.pdf}}, year = {{2013}}, }