scholarly journals Experimental and numerical investigation of thermal and fluid-flow processes in a matrix heat exchanger

2019 ◽  
Vol 23 (1) ◽  
pp. 11-21
Author(s):  
Mladen Tomic ◽  
Predrag Zivkovic ◽  
Biljana Milutinovic ◽  
Mica Vukic ◽  
Aleksandar Andjelkovic
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Perforated Plate ◽  
Hot Water ◽  
Experimental Chamber ◽  
Geometrical Parameters ◽  
The Matrix ◽  
Matrix Heat Exchanger ◽  
Matrix Heat

The need for compact heat exchangers has led to the development of many types of surfaces that enhance the rate of heat transfer, among them the matrix heat exchangers. These heat exchangers consist of a series of perforated plates mutually separated and sealed by spacers. The goal of this research was to investigate the heat transfer process of matrix heat exchangers on the air side, at the close to ambient conditions. The research was conducted in two directions ? experimental research and CFD research. The experimental investigation was carried out over a perforated plate package with the porosity of 25.6%. The air/water matrix heat exchanger was heated by hot water and was installed in an experimental chamber at which entrance was a fan with the variable flow rate and heated by hot water. The thermocouples were attached to the surface of the perforated plate at the upwind and downwind sides, as well as at the inlet and the outlet of the chamber. During each experiment, the thermocouple readings and the air and water-flow and temperatures were recorded. In the numerical part of the research, the matrix heat exchangers with different plate porosity from 10 to 50% were investigated. The results of the numerical simulations were validated against the experimental results. On the basis of the experimental and numerical results, equations for heat transfer as the function of Reynolds number and geometrical parameters was established.

scholarly journals PRELIMINARY DEVELOPMENT OF A CONCEPTUAL MODEL OF MATRIX HEAT EXCHANGER

2021 ◽  
Vol 24 (1) ◽  
pp. 29-40
Author(s):  
Claudia Bogdan ◽  
Catalin Brill ◽  
Oleksandr Sirosh ◽  
Mihai Vijulie ◽  
Alin Lazar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Perforated Plate ◽  
Hydrogen Isotopes ◽  
Inlet Temperature ◽  
Distillation Columns ◽  
Matrix Heat Exchanger ◽  
Cryogenic Distillation ◽  
Matrix Heat

While the basic principles of thermodynamics have remained the same, the necessity for heat exchangers to have good effectiveness in a small volume is constantly growing. Heat exchangers type Matrix Heat Exchanger (MHE), which can meet these requirements, does not have an optimal design variant for its use. These heat exchangers have been approached for 60 years, by many researchers, currently offering only an overview of the process. The mechanism of heat transfer in a matrix heat exchanger is complex, having three different thermal convection paths as well as thermal conduction through two different surfaces. This paper presents the simulations performed in ANSYS Workbench, combining all these heat transfer modes, for developing an optimal model of a perforated plate matrix heat exchanger, used for the pre-cooling of a hydrogen isotopes stream mixture, for purification purposes, as well as, for preparing the inlet temperature in cryogenic distillation columns of hydrogen isotopes.

Discussion: “Analysis of Matrix Heat Exchanger Performance” (Venkatarathnam, G., and Sarangi, S., 1991, ASME J. Heat Transfer, 113, pp. 830–836)

1998 ◽  
Vol 120 (3) ◽  
pp. 801-803
Author(s):  
V. Ahuja ◽  
R. K. Green
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Numerical Scheme ◽  
Approximate Analytical Solution ◽  
Full Effect ◽  
Matrix Heat Exchanger ◽  
Balanced Flow ◽  
Matrix Heat ◽  
Flow Case

Recently, a new numerical scheme for solving the equations governing matrix heat exchanger thermal performance was published in this journal. It was found that this scheme does not include the full effect of longitudinal heat transfer in the said heat exchangers. This effect is demonstrated by correcting the parameter related to longitudinal heat transfer in the approximate analytical solution for the balanced flow case and finding it to deviate considerably from the numerically calculated result.

scholarly journals Performance Analysis and Design Optimization of Shell and Tube Heat Exchangers

2021 ◽  
Author(s):  
praveen math
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Pressure Loss ◽  
Fluid Flows ◽  
Hot Water ◽  
Flow Conditions ◽  
Shell Side ◽  
Shell And Tube ◽  
Side Flow

Abstract Shell and Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre-heaters. They are also widely used in process applications as well as the refrigeration and air conditioning industry. The robustness and medium weighted shape of Shell and Tube heat exchangers make them well suited for high pressure operations. The aim of this study is to experiment, validate and to provide design suggestion to optimize the shell and tube heat exchanger (STHE). The heat exchanger is made of acrylic material with 2 baffles and 7 tubes made of stainless steel. Hot fluid flows inside the tube and cold fluid flows over the tube in the shell. 4 K-type thermocouples were used to read the hot and cold fluids inlet and outlet temperatures. Experiments were carried out for various combinations of hot and cold water flow rates with different hot water inlet temperatures. The flow conditions are limited to the lab size model of the experimental setup. A commercial CFD code was used to study the thermal and hydraulic flow field inside the shell and tubes. CFD methodology is developed to appropriately represent the flow physics and the procedure is validated with the experimental results. Turbulent flow in tube side is observed for all flow conditions, while the shell side has laminar flow except for extreme hot water temperatures. Hence transition k-kl-omega model was used to predict the flow better for transition cases. Realizable k- epsilon model with non-equilibrium wall function was used for turbulent cases. Temperature and velocity profiles are examined in detail and observed that the flow remains almost uniform to the tubes thus limiting heat transfer. Approximately 2/3 rd of the shell side flow does not surround the tubes due to biased flow contributing to reduced overall heat transfer and increased pressure loss. On the basis of these findings an attempt has been made to enhance the heat transfer by inducing turbulence in the shel l side flow. The two baffles were rotated in opposite direction to each other to achieve more circulation in the shell side flow and provide more contact with tube surface. Various positions of the baffles were simulated and studied using CFD analysis and th e results are summarized with respect to heat transfer and pressure loss.

scholarly journals An Experimentally Validated Numerical Modeling Technique for Perforated Plate Heat Exchangers

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
M. J. White ◽  
G. F. Nellis ◽  
S. A. Klein ◽  
W. Zhu ◽  
Y. Gianchandani
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Model ◽  
Heat Exchangers ◽  
Perforated Plate ◽  
Plate Heat Exchanger ◽  
Internal Temperature ◽  
Perforated Plates ◽  
Axial Conduction ◽  
Plate Heat

Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid.

Calculation of the Geometrical Parameters of the Heat Exchanger Type “Pipe in Pipe” with a Spiral-Coiled Channel

2019 ◽  
Vol 16 (11) ◽  
pp. 4513-4518 ◽  
Author(s):  
Valeriya Leonidovna Vorontsova ◽  
Alfiya Gizzetdinovna Bagoutdinova ◽  
Almaz Fernandovich Galemzianov
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Characteristic Size ◽  
Geometrical Parameters ◽  
Equivalent Diameter ◽  
Annular Space ◽  
Integral Calculus ◽  
Criterial Equations ◽  
Type Tube

The designs of the modern type of twisting devices include spring-twisted channels, which to use as innovative heat exchange elements of tubular apparatuses. The paper presents a method for determining the equivalent diameter of the tube and intertubular space in a heat exchanger apparatus of the type “tube-in-tube” with a spring-twisted channel which composed of tori closely adjacent to each other. Based on the integral calculus, formulas are obtained for calculating the equivalent diameters of the tube and annular space in a tube-in-tube apparatus with a spring-twisted channel. The results of experiments on heat transfer are generalized by criterial equations, in which the equivalent diameter is used as the characteristic size. It is shown that the equivalent diameters of the examined channels differ from each other by no more than 5%. The results of this work can be used in the design and calculations of promising heat exchangers with intensified heat transfer.

Comparison of stationary and rotary matrix heat exchangers using teaching-learning-based optimization algorithm

2017 ◽  
Vol 232 (4) ◽  
pp. 493-502 ◽  
Author(s):  
Hassan Hajabdollahi
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Optimization Algorithm ◽  
Heat Exchangers ◽  
Design Parameters ◽  
Matrix Heat Exchanger ◽  
Teaching Learning Based Optimization ◽  
Mass Flow Rates ◽  
Teaching Learning ◽  
Matrix Heat

In this paper, two kinds of compact heat exchanger including plate fin heat exchanger and rotary regenerator, respectively the stationary and rotary matrix heat exchanger, are compared. For this purpose, both heat exchangers are optimized by considering three simultaneous objective functions including effectiveness, heat exchanger volume, and total pressure drop using multi-objective teaching learning based optimization algorithm. Six different design parameters are considered for the both plate fin heat exchanger and rotary regenerator. Optimization is performed for the same and different hot and cold side mass flow rates. The optimum results reveal 13.26% growth in the effectiveness, 475.17% increase in the volume, and 95.45% reduction in the pressure drop in RR as compared with plate fin heat exchanger and for the final optimum point. As a result, rotary regenerator is more suitable in the case of high effectiveness and low pressure drop while plate fin heat exchanger is more suitable in the case of space limitation (lower heat exchanger volume).

Waste Heat Recovery Using Matrix Heat Exchanger from the Exhaust of an Automobile Engine for Heating Car’s Passenger Cabin

2014 ◽  
Vol 984-985 ◽  
pp. 1132-1137
Author(s):  
P. Muthusamy ◽  
Palanisamy Senthil Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Waste Heat ◽  
Working Fluid ◽  
Cold Fluid ◽  
Matrix Heat Exchanger ◽  
Matrix Heat ◽  
Passenger Cabin

The main objective of our work is to analysis the heat transfer rate for various fluids with different matrix heat exchanger (MHE) models and flow characteristic in matrix heat exchanger by using computational fluid dynamics (CFD) package with small car. The amount of heat carried by the cold fluid from hot fluid is mainly depends upon the mass flow rate of the working fluid. The heat transfer area per unit volume of tube is more. So, it increases the temperature of the cold fluid. Here, the hot and cold fluids are moving in the alternate tubes of heat exchanger in the counter flow direction. The small amounts of pressure drop are occurred but which is less compared to existing model. Flow disturbances are rectified in the MHE through the modifications made. Since, silicon carbide material is used as a polishing material to avoid the deposit of carbon at the inner side of the flow passage and this waste heat energy is used for heating passenger cabin during winter season. The wood is used as an insulating material to avoid the heat flow from fluid to atmosphere. Keywords-Heat transfer rate, Matrix heat exchanger, Working fluid, Polishing material.

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