scholarly journals Conserving heat consumption by modeling and optimizing efficiency of complex heat exchanger systems

2020 ◽  
Vol 154 ◽  
pp. 04004
Author(s):  
Tomasz Wyleciał ◽  
Dariusz Urbaniak ◽  
A. E. Barochkin ◽  
V. P. Zhukov ◽  
N. R. Leznova
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Analytical Solution ◽  
Heat Exchangers ◽  
Human Life ◽  
Heating Surface ◽  
Heat Losses ◽  
Rational Management ◽  
Linear Differential ◽  
The Impact

Many needs have to be met in human life. One of the key needs is to provide living comfort, which is clearly associated with heat. Analyzing the amount of produced heat, it should be emphasized that the higher the development of a country, the greater the demand for heat. In the era of the debate on the impact of human activities on the climate, it is impossible not to emphasize the importance of conserving energy and heat, and thus the rational management of these goods. The paper proposes a mathematical description of the complex systems of heat exchangers in the form of linear differential equations. Their analytical solution is presented in the form of temperature change of the heat carrier along the heating surface of a four-thread heat exchanger. Analysis of the possible heat exchange cases for eight possible flow systems is presented. In addition, the most effective minimization of heat losses was found.

A comprehensive survey on utilization of hybrid nanofluid in plate heat exchanger with various number of plates

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Faraz Afshari ◽  
Azim Doğuş Tuncer ◽  
Adnan Sözen ◽  
Halil Ibrahim Variyenli ◽  
Ataollah Khanlari ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Flow Behavior ◽  
Plate Heat Exchanger ◽  
Single Type ◽  
Hybrid Nanofluid ◽  
Content Type ◽  
Plate Heat ◽  
The Impact

Purpose Using suspended nanoparticles in the base fluid is known as one of the most efficient ways for heat transfer augmentation and improving the thermal efficiency of various heat exchangers. Different types of nanofluids are available and used in different applications. The main purpose of this study is to investigate the effects of using hybrid nanofluid and number of plates on the performance of plate heat exchanger. In this study, TiO2/water single nanofluid and TiO2-Al2O3/water hybrid nanofluid with 1% particle weight ratio have been used to prepare hybrid nanofluid to use in plate type heat exchangers with three various number of plates including 8, 12 and 16. Design/methodology/approach The experiments have been conducted with the aim of examining the impact of plates number and used nanofluids on heat transfer enhancement. The performance tests have been done at 40°C, 45°C, 50°C and 55°C set outlet temperatures and in five various Reynolds numbers between 1,600 and 3,800. Also, numerical simulation has been applied to verify the heat and flow behavior inside the heat exchangers. Findings The results indicated that using both nanofluids raised the thermal performance of all tested exchangers which have a various number of plates. While the major outcomes of this study showed that TiO2-Al2O3/water hybrid nanofluid has priority when compared to TiO2/water single type nanofluid. Utilization of TiO2-Al2O3/water nanofluid led to obtaining an average improvement of 7.5%, 9.6% and 12.3% in heat transfer of heat exchangers with 8, 12 and 16 plates, respectively. Originality/value In the present work, experimental and numerical analyzes have been conducted to investigate the influence of using TiO2-Al2O3/water hybrid nanofluid in various plate heat exchangers. The attained findings showed successful utilization of TiO2-Al2O3/water nanofluid. Based on the obtained results increasing the number of plates in the heat exchanger caused to obtain more increment by using both types of nanofluids.

Experimental Investigation of Forced Convection Enhancement by Acoustic Resonance Excitations in Turbulated Heat Exchangers

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Samuel Gendebien ◽  
Alex Kleiman ◽  
Boris Leizeronok ◽  
Beni Cukurel
Keyword(s):  
Heat Exchanger ◽  
Forced Convection ◽  
Heat Exchangers ◽  
Sound Pressure ◽  
Acoustic Resonance ◽  
Resonance Excitation ◽  
Minimal Form ◽  
Resonance Frequencies ◽  
Double Pipe ◽  
The Impact

Abstract The present research deals with enhancing the thermal performance of turbulated heat exchangers through the application of sound pressure waves at acoustic resonance frequencies. Extending the findings of prior wind tunnel studies, where a standing wave greatly improved the forced convection in reattaching flows, this paper exploits such a phenomenon in a practical heat exchanger setting. The current experiments are conducted in representative turbulated plate and double-pipe heat exchanger geometries, mounted in a dedicated facility. After identifying the inherent acoustic resonance frequencies of the passageways, the impact of excitation is studied in various sound pressure levels, blockage ratios, as well as Strouhal and Reynolds numbers. The acoustic resonance excitation resulted in heat transfer enhancement of 20% and 10% in the plate and double-pipe designs, respectively, absence of additional pressure penalties. To the best knowledge of the authors, this is the first demonstration of acoustic forced convection enhancement in turbulated heat exchanger geometries. Such a technology can pave the way toward future designs that require low-pressure losses, minimal form factor, and/or process controllability.

Experimental Investigation of Forced Convection Enhancement by Acoustic Resonance Excitations in Turbulated Heat Exchangers

2019 ◽  
Author(s):  
S. Gendebien ◽  
A. Kleiman ◽  
B. Leizeronok ◽  
B. Cukurel
Keyword(s):  
Heat Exchanger ◽  
Forced Convection ◽  
Heat Exchangers ◽  
Sound Pressure ◽  
Acoustic Resonance ◽  
Resonance Excitation ◽  
Minimal Form ◽  
Resonance Frequencies ◽  
Double Pipe ◽  
The Impact

Abstract The present research deals with enhancing thermal performance of turbulated heat exchangers through application of sound pressure waves at acoustic resonance frequencies. Extending the findings of prior wind tunnel studies, where a standing wave greatly improved the forced convection in reattaching flows, this paper exploits such a phenomenon in a practical heat exchanger setting. The current experiments are conducted in representative turbulated plate and double pipe heat exchanger geometries, mounted in a dedicated facility. After identifying the inherent acoustic resonance frequencies of the passageways, the impact of excitation is studied in various sound pressure levels, blockage ratios, as well as Strouhal and Reynolds numbers. The acoustic resonance excitation resulted in heat transfer enhancement of 20% and 10% in the plate and double pipe designs respectively, absent of additional pressure penalties. To the best knowledge of the authors, this is the first demonstration of acoustic forced convection enhancement in turbulated heat exchanger geometries. Such a technology can pave the way towards future designs that require low pressure losses, minimal form factor and/or process controllability.

scholarly journals About mathematical modeling of aerodynamic characteristics in devices with a leakage of the impact systems of plane-parallel streams on the heat exchange surface

2018 ◽  
Vol 170 ◽  
pp. 03024
Author(s):  
Larisa Haritonova ◽  
Valery Azarov ◽  
Igor Stefanenko
Keyword(s):  
Heat Exchange ◽  
Heat Exchangers ◽  
Aerodynamic Resistance ◽  
Aerodynamic Characteristics ◽  
Plane Parallel ◽  
Heat Exchange Surface ◽  
Parallel Streams ◽  
The Impact ◽  
The Mathematical Model ◽  
Exchange Surface

The article is devoted to the development of the general aerodynamic theory in case of a leakage by the systems of plane-parallel impact jets on the plane heat exchange surface [1-2]. An analytical generalization of data on aerodynamic resistance with the blowout of flat surface by the system of the plane-parallel impact jets was implemented. These data were obtained as a result of the application of mathematical theory of planning an experiment. The equations of regression are the mathematical model of process. Functional dependences between the constructive factors and the regime parameters of these first obtained experimental dependences on aerodynamic resistance in the jet heat exchangers with the leakage of air in the form of the system of plane-parallel jets were established. Results of work can be used in developing of different methods of calculation for various new designs of highly effective heat exchangers or their optimization for various branches.

scholarly journals The use of porous metals in the design of heat exchangers to increase the intensity of heat exchange

2020 ◽  
Vol 178 ◽  
pp. 01026
Author(s):  
Natalia Rydalina ◽  
Oleg Stepanov ◽  
Elena Antonova
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Analytical Form ◽  
Test Facility ◽  
Porous Metals ◽  
Heat Supply Systems ◽  
Set Up ◽  
Supply Systems

Heat exchangers are widely used in heat supply systems. To increase the efficiency of heat supply systems, heat exchangers with porous metals are proposed to design. There was a test facility set up to study new types of heat exchangers. The countercurrent flow of heat carriers was activated in those heat exchangers. Freon moved through the heat exchanger pores, and water moved through the inner tubes. It should be noted that the porous materials in the heat exchangers differed in the coefficient of porosity. To be compared, one of the heat exchangers did not contain any porous material. The first test cycle proved the feasibility of using porous metals in heat exchange equipment. Afterwards, a simplified mathematical model of the heat exchanger was compiled. Such an analytical form makes a solution convenient for engineering calculations. Numerical calculations based on this model were compared with the experimental data. Heat transfer intensity of materials with different porosity was compared.

scholarly journals Horizontal earth-air heat exchanger for preheating external air in the mechanical ventilation system

2018 ◽  
Vol 13 (1) ◽  
pp. 71-76
Author(s):  
Vasyl Zhelykh ◽  
Olena Savchenko ◽  
Vadym Matusevych
Keyword(s):  
Heat Transfer ◽  
Mechanical Ventilation ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Convective Heat Transfer Coefficient ◽  
Ventilation System ◽  
Heat Pipes ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Abstract To save traditional energy sources in mechanical ventilation systems, it is advisable to use low-energy ground energy for preheating or cooling the outside air. Heat exchange between ground and outside air occurs in ground heat exchangers. Many factors influence the process of heat transfer between air in the heat exchanger and the ground, in particular geological and climatic parameters of the construction site, parameters of the ventilation air in the projected house, physical and geometric parameters of the heat exchanger tube. Part of the parameters when designing a ventilation system with earth-air heat exchangers couldn’t be changed. The one of the factors, the change which directly affects the process of heat transfer between ground and air, is convective heat transfer coefficient from the internal surface of the heat exchanger tube. In this article the designs of a horizontal earthair heat exchanger with heat pipes was proposed. The use of heat pipes in designs of a horizontal heat exchanger allows intensification of the process of heat exchange by turbulence of air flow inside the heat exchanger. Besides this, additionally heat transfer from the ground to the air is carried out at the expense of heat transfer in the heat pipe itself.

scholarly journals Evaluation and Improvement of Thermal Energy of Heat Exchangers with SWCNT, GQD Nanoparticles and PCM (RT82)

2020 ◽  
Vol 79 (1) ◽  
pp. 153-168
Author(s):  
Mohammadreza Hasandust Rostami ◽  
Gholamhassan Najafi ◽  
Ali Motevalli ◽  
Nor Azwadi Che Sidik ◽  
Muhammad Arif Harun
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Phase Change Materials ◽  
Single Wall Carbon Nanotubes ◽  
In Series

Today, due to the reduction of energy resources in the world and its pollutants, energy storage methods and increase the thermal efficiency of various systems are very important. In this research, the thermal efficiency and energy storage of two heat exchangers have been investigated in series using phase change materials (RT82) and single wall carbon nanotubes (SWCNT) and graphene quantum dot nanoparticles (GQD) In this research, two heat exchangers have been used in combination. The first heat exchanger was in charge of storing thermal energy and the second heat exchanger was in charge of heat exchange. The reason for this is to improve the heat exchange of the main exchanger (shell and tube) by using heat storage in the secondary exchanger, which has not been addressed in previous research. The results of this study showed that using two heat exchangers in series, the thermal efficiency of the system has increased. Also, the heat energy storage of the double tube heat exchanger was obtained using phase change materials in the single-walled carbon nanotube composition of about 3000 W. The average thermal efficiency of the two heat exchangers as the series has increased by 52%. In general, the effect of the two heat exchangers on each other was investigated in series with two approaches (energy storage and energy conversion) using fin and nanoparticles, which obtained convincing results.

scholarly journals Features of creation and use of effective heat exchangers

2020 ◽  
Vol 216 ◽  
pp. 01124
Author(s):  
Shavkat Agzamov ◽  
Sevinar Nematova
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Prandtl Number ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Heat Transfer Equation ◽  
The Heat Transfer Coefficient ◽  
Outside Diameter

The article discusses the features of the creation and use of efficient heat exchanger. Designs of pipes with a developed heat exchange is presented. The procedure for determining the degree of development of the heat exchanging surface, the heat transfer coefficient, and the calculation of the heat transfer equation are given. As a result of creating efficient heat exchangers, three main parameters are used: the pipe outside diameter; the estimated flow rate; the Prandtl number.

Fabrication of Taper Gap Warm End Heat Exchanger in Coaxial Pulse Tube Cryocooler

2012 ◽  
Vol 591-593 ◽  
pp. 365-368 ◽  
Author(s):  
Kai Xiang Yang ◽  
Yi Nong Wu ◽  
An Kuo Zhang ◽  
Chao Xiong
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Coupling Effect ◽  
Infrared Detector ◽  
Low Noise ◽  
Pulse Tube ◽  
Paper Briefly ◽  
Pulse Tube Cryocooler ◽  
The Given

Coaxial pulse tube cryocooler (PTC) acquires a perfect substitute for the existing Stirling cryocooler for providing reliable low-noise cooling for the given infrared detector system. The challenging work is the exacting requirement on its dimensions which have to adapt to the given Dewar.Warm end heat exchanger is the key assembly of the pulse tube cryocooler,and the coupling effect especially the heat exchange of the gas and solid in warm end heat exchanger directly affects the performance of the pulse tube cryocooler ,this paper briefly analyzes the differences of warm end heat exchangers in the form of cylinder gap,cylinder copper screen and taper gap.The status of every type of warm end heat exchanger are outlined, including the fabricating material and technique kernel , and especially introduce the taper gap warm end exchanger.In the end of the paper we conclude that the taper gap warm end exchanger can apparently improve the performance and minish the volume of the of the pulse tube cryocooler

Problems of the Heat Exchanger for Vehicular Gas Turbines

1976 ◽  
Author(s):  
E. Tiefenbacher
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Gas Turbine ◽  
Fuel Consumption ◽  
Heat Exchangers ◽  
Gas Turbines ◽  
Flow Distribution ◽  
Short Review ◽  
Piston Engine

It is well known that a vehicular gas turbine needs a heat exchanger to compete in fuel consumption with the piston engine, especially with the diesel. A short review of the theory of heat exchange shows that very small hydraulic diameters must be used to obtain a reasonable heat exchanger volume. This causes a number of problems for the fabrication, engine configuration, flow distribution, etc. These problems are discussed in conjunction with experience gained during the development of a number of heat exchangers (1).

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