Local shell-side heat transfer coefficients and pressure drop in a tubular heat exchanger with orifice baffles

AIChE Journal ◽  
1960 ◽  
Vol 6 (4) ◽  
pp. 669-675 ◽  
Author(s):  
K. S. Lee ◽  
J. G. Knudsen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficients ◽  
Shell Side ◽  
Tubular Heat Exchanger ◽  
Heat Transfer Coefficients

Experimental Study and Genetic-Algorithm-Based Correlation on Shell-Side Heat Transfer and Flow Performance of Three Different Types of Shell-and-Tube Heat Exchangers

2006 ◽  
Vol 129 (9) ◽  
pp. 1277-1285 ◽  
Author(s):  
Qiu-wang Wang ◽  
Gong-nan Xie ◽  
Bo-tao Peng ◽  
Min Zeng
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Transfer Coefficients ◽  
Shell Side ◽  
Heat Transfer Coefficients ◽  
Friction Factors ◽  
Shell And Tube

The heat transfer and pressure drop of three types of shell-and-tube heat exchangers, one with conventional segmental baffles and the other two with continuous helical baffles, were experimentally measured with water flowing in the tube side and oil flowing in the shell side. The genetic algorithm has been used to determine the coefficients of correlations. It is shown that under the identical mass flow, a heat exchanger with continuous helical baffles offers higher heat transfer coefficients and pressure drop than that of a heat exchanger with segmental baffles, while the shell structure of the side-in-side-out model offers better performance than that of the middle-in-middle-out model. The predicted heat transfer rates and friction factors by means of the genetic algorithm provide a closer fit to experimental data than those determined by regression analysis. The predicted corrections of heat transfer and flow performance in the shell sides may be used in engineering applications and comprehensive study. It is recommended that the genetic algorithm can be used to handle more complicated problems and to obtain the optimal correlations.

Size Effect on Thermal Characteristic of Tubular Heat Exchanger at Miniscale and Microscale

2018 ◽  
Vol 11 (2) ◽  
Author(s):  
Ankush D. Tharkar ◽  
Shripad P. Mahulikar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Performance Parameter ◽  
Annular Space ◽  
Transfer Coefficients ◽  
Tubular Heat Exchanger ◽  
Heat Transfer Coefficients ◽  
Convective Heat Transfer Coefficients

Abstract The scope for the heat transfer enhancement in the tubular heat exchanger is high due to its unique property of having two separate convective heat transfer coefficients. The variation of diameter and annular space has a direct effect on the value of convective heat transfer coefficients due to their inverse relation. Thus, the strong emphasis must be given on the influence of diameter and annular space on the thermal characteristics of the tubular heat exchanger. In this numerical analysis, peculiarities in the improvement of the performance parameters are studied with the variation in the value of inlet velocities of the fluids (cold and hot), inner pipe diameter, and annular space for the combination of dimensional range such as miniscale and microscale range. The inner tube diameter is observed to be sensitive to the improvement in the performance parameter. The growth in the performance parameter of the tubular micro heat exchanger is found to be higher when both the values of diameter and annular space are in the microscale range.

Dimensionless Analysis of Heat Transfer and Flow Resistance on Laminar Flow Recuperator

2008 ◽  
Author(s):  
Chunyu Yin ◽  
Xiaoyong Yang ◽  
Jie Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Flow Resistance ◽  
Similarity Theory ◽  
Installation Space ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Dimensionless Analysis

Recuperator is one of the key components in the helium-turbine cycle coupled with High Temperature Gas cooled Reactor (HTGR). Synthetically considering the heat transfer coefficients, the pressure drop and installation space of recuperator, it is obviously a trend to use compact heat exchanger as recuperator in nuclear power plant. Recuperator recovers heat from the turbine exhaust gas. It promotes the cycle efficiency over entire power range and in all typical modes including start up and shut down modes. The recuperator’s heat transfer coefficients, height, pressure drop have effect on the recuperator’s effectiveness. The main purpose of this paper is to present the law of heat transfer and flow resistance in laminar flow compact exchanger. Based on the similarity theory, the dimensionless parameters of the plate-fin heat exchanger is given in this paper; and then the the dimensionless analysis of the over-all heat transfer coefficient, recuperator’s effectiveness and flow resistance is presented. Furthermore, relationship between the pressure drop and length is also developed.

Cost-Optimal Operation of Heat Exchanger Network Considering Pressure Drop Constraints

2013 ◽  
Vol 634-638 ◽  
pp. 3898-3902
Author(s):  
Liang Zhao ◽  
Zhao Yi Huo ◽  
Lin Mu ◽  
Hong Chao Yin
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Optimal Operation ◽  
Extended Model ◽  
Transfer Coefficients ◽  
Heat Exchanger Network ◽  
Power Cost ◽  
Heat Transfer Coefficients ◽  
Film Heat Transfer

Considerable research effort has been reported in cost-optimal operation of heat exchanger network. However, most of them neglect the pressure drop influence and assume constant film heat transfer coefficients. Pressure drop of streams are important influencing factors for the performance of heat exchanger network operation. In this paper, a general cost-optimal operation model considering pressure drop constraints and removing the assumption of constant film heat transfer coefficients is proposed. It is necessary to determine the pumping power cost required as part of operating cost function. The extended model is applied to one example taken from previous research, and the results prove that the proposed method can obtain more real optimization results for HEN operational optimization problems.

scholarly journals A Novel Generator Design Utilised for Conventional Ejector Refrigeration Systems

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7705
Author(s):  
Anas F. A. Elbarghthi ◽  
Mohammad Yousef Hdaib ◽  
Václav Dvořák
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Working Fluid ◽  
Convection Coefficient ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Heat Transfer Coefficients ◽  
Cold Fluid ◽  
Cold Stream

Ejector refrigeration systems are rapidly evolving and are poised to become one of the most preferred cooling systems in the near future. CO2 transcritical refrigeration systems have inherently high working pressures and discharge temperatures, providing a large volumetric heating capacity. In the current research, the heat ejected from the CO2 gas cooler was proposed as a driving heating source for the compression ejector system, representing the energy supply for the generator in a combined cycle. The local design approach was investigated for the combined plate-type heat exchanger (PHE) via Matlab code integrated with the NIST real gas database. HFO refrigerants (1234ze(E) and 1234yf) were selected to serve as the cold fluid on the generator flowing through three different phases: subcooled liquid, a two-phase mixture, and superheated vapour. The study examines the following: the effectiveness, the heat transfer coefficients, and the pressure drop of the PHE working fluids under variable hot stream pressures, cold stream flow fluxes, and superheated temperatures. The integration revealed that the cold fluid mixture phase dominates the heat transfer coefficients and the pressure drop of the heat exchanger. By increasing the hot stream inlet pressure from 9 MPa to 12 MPa, the cold stream two-phase convection coefficient can be enhanced by 50% and 200% for R1234yf and R1234ze(E), respectively. Conversely, the cold stream two-phase convection coefficient dropped by 17% and 37% for R1234yf and R1234ze(E), respectively. The overall result supports utilising the ejected heat from the CO2 transcritical system, especially at high CO2 inlet pressures and low cold channel flow fluxes. Moreover, R1234ze(E) could be a more suitable working fluid because it possesses a lower pressure drop and bond number.

Performance of a Plate Heat Exchanger Operated with Water-Al2O3 Nanofluid

2016 ◽  
Vol 831 ◽  
pp. 188-197 ◽  
Author(s):  
Janusz T. Cieśliński ◽  
Artur Fiuk ◽  
Wojciech Miciak ◽  
Bartłomiej Siemieńczuk
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Plate Heat Exchanger ◽  
Transfer Coefficients ◽  
Plate Heat ◽  
Heat Transfer Coefficients ◽  
Overall Heat Transfer Coefficient ◽  
Weight Impact ◽  
Brazed Plate Heat Exchanger

This study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break of operation of the tested PHEx on its performance was of particular interest. Pressure drop in all runs was measured as well. The Wilson approach was applied in order to estimate heat transfer coefficients for the PHEx passages. It was observed, that addition of nanoparticles resulted in deterioration of an overall heat transfer coefficient for the selected PHEx and tested conditions, i.e. temperature range and Reynolds number. Moreover, substantial increase of pressure drop was recorded after each break of operation of the tested PHEx.

Internal, Shellside Heat Transfer and Pressure Drop Characteristics for a Shell and Tube Heat Exchanger

1985 ◽  
Vol 107 (2) ◽  
pp. 345-353 ◽  
Author(s):  
E. M. Sparrow ◽  
J. A. Perez
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Thermal Loading ◽  
Compartment Pressure ◽  
Transfer Coefficients ◽  
Pressure Drops ◽  
Tube Heat Exchanger ◽  
Heat Transfer Coefficients ◽  
Shell And Tube

Per-tube heat transfer coefficients and per-compartment and intracompartment pressure drops were measured on the shell side of a shell and tube heat exchanger. The main focus of the work was to determine the response of these quantities to variations in the size of the baffle window; the Reynolds number was also varied parametrically. The pressure measurements showed that the fluid flow is fully developed downstream of the first compartment of the heat exchanger and that the per-compartment pressure drop is constant in the fully developed regime. Within a compartment, the pressure drop in the upstream half is much larger than that in the downstream half. The per-tube heat transfer coefficients vary substantially within a given compartment (on the order of a factor of two), giving rise to a nonuniform thermal loading of the tubes. Row-average and compartment-average heat transfer coefficients were also evaluated. The lowest row-average coefficients were those for the first and last rows in a compartment, while the highest coefficient is that for the row just upstream of the baffle edge. It was demonstrated that the per-tube heat transfer coefficients are streamwise periodic for a module consisting of two consecutive compartments.

scholarly journals Experimental Investigation of the Heat Transfer and Pressure Drop inside Tubes and the Shell of a Minichannel Shell and Tube Type Heat Exchanger

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8563
Author(s):  
Mateusz Prończuk ◽  
Anna Krzanowska
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Inner Diameter ◽  
Shell And Tube

This paper presents an experimental study on a shell and tube mini heat exchanger (STMHE). The STMHE consisted of seven tubes in a triangular arrangement, with an 0.8 mm inner diameter and 1.0 mm outer diameter. The heat exchanger shell had an inner diameter of 11 mm, and the heat exchanger had no baffles. For the adopted operating conditions, the Reynolds number on the tube side varied in the range of 300–3000, and 2000–12,000 on the shell side. The aim of this study was to determine pressure drop values during fluid flow and Nusselt number correlations for the heat transfer. A new method based on optimisation was used to derive the equations for calculating the heat transfer coefficients. It allowed the determine of the correlation equations for the heat transfer coefficients simultaneously for both sides of the heat exchanger. The obtained correlations yielded overall heat transfer coefficient values that, in most cases, did not differ by more than from those determined experimentally. The experimentally determined critical Reynolds number value for the flow inside the tubes was equal to . The Darcy friction factors correlated well with the classical laminar flow correlation and with the Blasius correlation for turbulent flow. The derived correlations for the Nusselt number were best aligned with the Sieder–Tate, Gnielinski, and Kozioł correlations for tube side laminar flow, turbulent flow, and shell flow, respectively. Good agreement between the results obtained using the experimentally derived correlations and the correlations available in the literature confirms the effectiveness of the used optimisation–based method.

Sign in / Sign up

Export Citation Format

Share Document