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1

Impact of honeycomb straightener parameters on operation in a straight duct

Smyk Emil, Stopel Michał, Rachwalski Adam

Journal of Theoretical and Applied Mechanics

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2025

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Vol. 63 nr 4

781--794

EN

The influence of the honeycomb diameter and straightener length on performance was investigated. Velocity profiles were measured using a hot-wire anemometer, and pressure losses were also recorded. The straighteners were placed 10D downstream of the fan. Measurements were conducted at Reynolds numbers of 10000, 15000, 30000, 45000. Additionally, two methods were proposed to assess the influence of straighteners on the shape of the velocity profile. The results showed that at Reynolds numbers of 10000 and 15000, straighteners had only a minor effect on reducing turbulence intensity and relaminarizing the velocity profile. In contrast, at higher Reynolds numbers, their impact was significant.

2

The Influence of Flow Rate on CIP Cleaning Efficiency and Flow Resistance in an Installation with a Three-Section PHE

Galiński Maksymilian, Bieńczak Agata, Ignasiak Łukasz, Kiczek Tomasz, Michalak Tomasz, Woźniak Paweł, Maziarz Karolina

Journal of Research and Applications in Agricultural Engineering

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2025

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Vol. 70, nr 1

39--47

EN

Due to the widespread application of plate heat exchangers (PHE) in the food industry, a key aspect of their operation is ensuring a high level of hygiene, which guarantees the microbiological cleanliness of the final product. This is achieved through the cleaning of installations containing PHE using the Clean-in-Place (CIP) system. An important aspect is the determination of flow resistance, as this enables the specification of drive parameters and the selection of a pump that provides a sufficiently high flow rate through the installation, particularly required during the pre-rinsing stage. The subject of the research was a three-section plate heat exchanger, which forms part of a prototype technological line designed for the pasteurisation of liquid egg mass and its fractions – egg white and yolk. As part of the study, the effectiveness of the cleaning process was assessed depending on the flow rate. Based on experimental results, the minimum flow rate necessary for effective cleaning using commercial sodium hydroxide (NaOH)-based cleaning agents was determined. In addition, the extent to which the relationship described in the literature – linking flow rate with hydraulic resistance in PHE – is confirmed under real operating conditions during the cleaning process in the CIP system was analysed. The results obtained may be used to optimise the parameters of the CIP process, which will contribute to increased efficiency, reduced consumption of chemical agents, and improved microbiological safety of the final product.

3

Numerical-experimental analysis of the process of delivering a repair system by a bypass pig to a hard-to-reach place of the pipeline

Bondarenko R. V., Doroshenko Ya. V.

Journal of Achievements in Materials and Manufacturing Engineering

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2025

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Vol. 130, nr 1

14--28

EN

Purpose: Analysis of gas-dynamic processes occurring during the delivery of a repair system through a pipeline by a bypass pig to a local defect located in a hard-to-reach place behind an elbow. Determination of the patterns of influence of the axial hole diameter in the bypass pig on the pressure drop and the driving force acting on it. Investigation of the conditions under which bypass pigs become stuck in the elbows of the pipeline and assessment of the risk of overloading the repair system components during their delivery. Design/methodology/approach: The methodological basis of the study is grounded on the combination of CFD modelling of gas-dynamic processes and laboratory experimental tests of the interaction between the bypass pig and the airflow during the delivery of a repair system through a pipeline containing an elbow to a local wall defect. Numerical and experimental results were compared for model verification. Findings: As the bypass pig’s axial hole diameter decreases, the pressure drop and the driving force acting on it increase significantly. For a hole diameter of 6 mm, the driving force reaches 170.8 N, which provides a large pulling force for moving the repair system, but creates a risk of flexible tube damage when the pig stops directly behind the local wall defect until the air supply from the compressor is shut off. For an axial hole diameter of 14 mm, the driving force decreases to 6.6 N, making it impossible to pass through pipeline elbows. The optimal solution is to select the maximum possible hole diameter that still ensures sufficient driving force for pig motion while meeting the strength limitations of the repair system components. Research limitations/implications: Although it has been established that when the diameter of the axial hole in the bypass pig exceeds 10.5 mm, the driving force becomes insufficient to overcome pipeline elbows (for example, at 14 mm the pig gets stuck), the quantitative criteria of the minimum required pressure drop remain undefined. To determine them, further studies of the contact interaction between the bypass pig made of elastic material and the pipe wall in curved sections are necessary. At small axial hole diameters (for example, 6 mm), the tensile force in the flexible tube of the repair system can reach 170 N, creating a risk of its damage or failure. To assess the operability of the flexible tube under such loads, it is advisable to perform strength calculations based on the mechanics of deformable solids. Practical implications: The results obtained in this study have practical significance for the development of in-line repair technologies of pipeline networks in hard-to-reach places, particularly behind fittings such as elbows. The work provides a foundation for the development and implementation of practical methodologies for selecting the design parameters of bypass pigs and the operating modes of the pipeline during the delivery of repair systems to hard-to-reach places. Originality/value: The results of CFD modelling and laboratory experiments were combined to establish the features of the process in which a bypass pig pulls a repair system through a pipeline with an elbow. The influence of the bypass pig’s axial hole diameter on the pressure drop and the driving force acting on it was determined, and the risks of pigs with large axial hole diameters getting stuck in elbows were demonstrated.

4

Nowa wkładka mieszająca do mieszalników statycznych w instalacjach budynkowych - wyniki badań CFD i doświadczalnych

Kordas Marian, Witkiewicz Konrad, Kiełbus-Rąpała Anna, Ignaczak Wojciech, Czajkowska Magdalena, Rakoczy Rafał, Jaworski Piotr

Instal

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2025

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nr 12

33--37

PL

W artykule przedstawiono nowe rozwiązanie konstrukcyjne wkładki mieszającej do mieszalników statycznych montowanych w przewodach cylindrycznych. Na podstawie przeglądu literatury i rozwiązań patentowych z zakresu mieszalników statycznych oraz wyników obliczeń CFD opracowano trzy warianty wkładek: ażurową przegrodę skręconą, pełną przegrodę skręconą oraz wkładkę kompozytową łączącą obie koncepcje. W części eksperymentalnej wykonano prototypową instalację badawczą i zmierzono spadek ciśnienia w mieszalniku z różnymi konfiguracjami wkładek, a także dla wkładki typu Kenics i dla pustej rury. Wyznaczono współczynnik oporów przepływu f oraz współczynnik spadku ciśnienia Z w funkcji liczby Reynoldsa. Wyniki wskazują, że wkładka kompozytowa o przeciwbieżnym skręceniu części pełnej i ażurowej zapewnia spadki ciśnienia porównywalne z klasyczną wkładką Kenics, przy jednoczesnym korzystnym rozkładzie pól prędkości i ciśnienia w warstwie przyściennej. Omówiono możliwości zastosowania nowej wkładki w instalacjach centralnego ogrzewania, ciepłej wody, instalacjach chłodniczych oraz układach z odnawialnymi źródłami energii.

EN

The paper presents a new structural solution for a mixing insert intended for static mixers installed in cylindrical pipes. Based on a review of the literature and patent solutions in the field of static mixers, as well as on CFD calculations, three variants of inserts were developed: a twisted lattice baffle, a twisted solid baffle, and a composite insert combining both concepts. In the experimental part, a prototype test installation was built and the pressure drop in the mixer was measured for various insert configurations, as well as for a Kenics-type insert and for an empty pipe. On this basis, the friction factor f and the pressure drop coefficient Z were determined as functions of the Reynolds number. The results indicate that the composite insert with counter-rotating solid and lattice sections provides pressure drops comparable to a classical Kenics insert, while ensuring favourable velocity and pressure fields in the near-wall region. The potential applications of the new insert in central heating installations, domestic hot water systems, refrigeration installations and renewable energy systems are discussed.

5

Specific aspects of hydrodynamic cavitation in water treatment. An overview

Viktor Voroshchuk, Kravets Oleh, Drozdziel Pawel, Rudawska Anna

Economics and Environment

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2025

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No. 4

art. no. 1363

EN

This paper reviews the development and applications of hydrodynamic cavitation in water treatment, with a particular emphasis on the removal of organic and microbiological contaminants. A comparative analysis of published studies is conducted to evaluate the performance of various cavitation configurations, including Venturi tubes, diaphragm systems, and rotor-stator devices. The findings show that hydrodynamic cavitation combines mechanical, thermal, and radical mechanisms that enable the degradation of dyes, pharmaceutical residues, and persistent organic pollutants, as well as the inactivation of pathogenic microorganisms. The analysis identifies cavitation number, flow velocity, pressure drop, and physicochemical properties of the medium as key factors influencing process efficiency. Practical implications include reduced chemical demand and lower energy consumption compared with conventional disinfection methods. The review highlights the potential of hybrid systems (HC+H2O2, HC+O3, HC+TiO3/UV), which often achieve over 90% COD and TOC removal, and indicates directions for optimisation and scale-up of cavitation reactors.

PL

Celem artykułu jest przedstawienie aktualnego stanu wiedzy na temat zastosowań kawitacji hydrodynamicznej w oczyszczaniu wody oraz identyfikacja kluczowych uwarunkowań procesowych. Zastosowano metodę systematycznego przeglądu literatury obejmującą badania z lat 2015-2025. Analiza uwzględnia mechanizmy działania kawitacji, parametry hydrodynamiczne, właściwości fizykochemiczne cieczy oraz efektywność różnych konfiguracji urządzeń. Szczególna uwaga poświęcona jest hybrydowym rozwiązaniom (HC+H2O2, HC+O3, HC+TiO3/UV), które osiągają ponad 90% redukcji zanieczyszczeń organicznych (COD i TOC). Przedstawiono także ograniczenia wynikające z różnorodności geometrii reaktorów, braku standaryzacji parametrów oraz niewystarczającej liczby badań pilotowych. Wartością dodaną pracy jest systematyzacja czynników wpływających na skuteczność kawitacji oraz wskazanie kierunków dalszych badań istotnych dla praktycznej implementacji technologii.

6

Analysis of the filtration process of inlet air to an internal combustion engine in a two-stage filter

Dziubak Tadeusz

Combustion Engines

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2025

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R. 64, nr 4

87--102

EN

The destructive effect of mineral dust grains (SiO2 and Al2O3) on the accelerated abrasive wear of engine connections was demonstrated. It was shown that the use of two-stage (multi-cyclone-baffle) air intake filters for motor vehicle engines used in conditions of high air dustiness is necessary. The aim of the work was a theoretical and experimental analysis of the properties of paper filters operating in series behind a cyclone and without a cyclone. An original research methodology was used, which consisted of the simultaneous testing of a single cyclone and a paper filter with an appropriately selected surface area. The system tests (cyclone-paper filter) were carried out using conditions that corresponded to the actual filtration conditions in a two-stage air filter, including the filtration speed in the paper bed, the dust concentration in the air sucked into the engine, and the average cyclone inlet speed. The basic filtration characteristics of filtration efficiency, accuracy, and pressure drop of two paper filters were determined as a function of the dust mass fed to the system (cyclone-paper filter) or directly to the characteristic filter. It was found that the paper filter operating in series behind the cyclone achieves four times longer operating time, limited by a specific value of permissible resistance. In the initial (short) filtration period, lower filtration efficiency values were obtained than the required value of 99.5%. On the other hand, dust grains with a maximum size of 13.5 μm were found in the air behind the paper filter. The required filtration accuracy of the engine intake air is in the range of 2-5 μm. For this reason, the initial air filtration period is an undesirable phenomenon and may cause accelerated engine wear.

7

Long-term operation of pulse-jet filters for wood dust

Rogoziński Tomasz, Dembiński Czesław, Potok Zbigniew, Ockajova Alena, Kucera Martin, Kminiak Riichard

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2023

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No. 121

61--65

EN

Long-term operation of pulse-jet filters for wood dust. The study specifies the value of flow resistance and separation efficiency of filter material during long-term use in pulse-jet filters for wood dust. The experiments were carried out for one type of material working in two different filtration installations in one furniture factory. The bags were obtained from the installations after working for 67, 133 and 272 days, respectively. All tests were performed on the pilot-scale test stand under identical filtration conditions. Studies have shown that long-term filter material use increases airflow resistance and improves filtration efficiency. The range of these changes depends on the operating conditions of the pulse-jet filters. The obtained results made it possible to determine the properties of the long-term use of filter materials in various filtration conditions.

PL

Długotrwała eksploatacja pulsacyjnych filtrów dla pyłu drzewnego. W pracy określono wartość oporów przepływu i skuteczność separacji materiału filtracyjnego podczas długotrwałego użytkowania w pulsacyjnych filtrach dla pyłu drzewnego. Eksperymenty przeprowadzono dla jednego rodzaju materiału pracującego w dwóch różnych instalacjach filtracyjnych w jednej fabryce mebli. Worki pozyskano z instalacji po odpowiednio 67, 133 i 272 dniach pracy. Wszystkie testy przeprowadzono na stanowisku pilotażowym w identycznych warunkach filtracji. Badania wykazały, że długotrwałe stosowanie materiału filtracyjnego zwiększa opory przepływu powietrza i poprawia skuteczność filtracji. Zakres tych zmian zależy od warunków pracy filtrów impulsowo-strumieniowych. Uzyskane wyniki pozwoliły na określenie właściwości przy długotrwałym użytkowaniu materiałów filtracyjnych w różnych warunkach filtracji.

8

Pressure drops during the flow of solutions of cocamidopropyl betaine and cocamide DEA mixtures with the addition of ethylene glycol

Różańska Sylwia, Różański Jacek, Wagner Patrycja, Warmbier Ewelina

Polish Journal of Chemical Technology

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2022

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Vol. 24, nr 4

67--71

EN

The paper presents the results of experimental studies on pressure drops during the flow of cocamidopropyl betaine (CAPB) and DEA cocamide solutions with the addition of ethylene glycol. The degree of drag reduction during the flow of the CAPB/DEA aqueous solution and with the 10% addition of ethylene glycol was similar. A significant reduction in pressure drops was also observed at the 20% concentration of ethylene glycol. However, the increase in the concentration of ethylene glycol resulted in the reduction of flow resistance at higher temperatures. The resistance of the micellar microstructure of CAPB/DEA solutions to mechanical degradation depends strongly on the pH level. Significant changes in flow properties were observed when the initial pH was alkaline. The solution with initial pH close to neutral was stable over time, though reduced resistance to degradation with time was also observed.

9

Requirement of pressure relief dampers for clean rooms

Hrnková Bronislava, Hečko Dávid, Kapjor Andrej, Mičko Pavol, Vantúch Martin

Structure and Environment

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2021

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Vol. 13, no. 2

55--58

EN

The clean room is designed and used to minimize the entry, generation and deposition of pollutants. Proper flow control is an important factor in determining the efficiency of clean rooms. It is important that the air stream entrains from the space all the particles that are released when people move, but also from equipment and various materials. Therefore, in the following article we will deal with the need for pressure dampers in clean rooms.

PL

Pomieszczenie czyste jest zaprojektowane i wykorzystywane w taki sposób, aby zminimalizować wnikanie, generowanie i osadzanie się zanieczyszczeń. Właściwa kontrola przepływu powietrza jest istotnym czynnikiem określającym efektywność pomieszczeń czystych. Ważne jest, żeby strumień powietrza porywał z przestrzeni wszystkie cząstki, które są uwalniane podczas ruchu ludzi, ale także ze sprzętu i różnych materiałów. W związku z powyższym w niniejszym artykule zajmiemy się potrzebą stosowania klap nadciśnieniowych w pomieszczeniach czystych.

10

Analiza numeryczna spadku ciśnienia w zaworze maksymalnym układu smarowania pojazdów spalinowych

Mazur Klaudia

Journal of TransLogistics

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2021

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Vol. 7, nr 1

85--98

PL

W poniższej pracy przedstawiono analizę przepływu oleju przez zawór przelewowy typu UDZB firmy PONAR Wadowice wykorzystywany w układach smarowania. Ma to na celu przedstawienie zachodzących zjawisk podczas zmiany wielkości szczeliny w zaworze. W pracy zawarte są informacje dotyczące spadku ciśnienia – czym jest spowodowany oraz jakie mogą być jego skutki.

EN

The paper below presents an analysis of the oil flow through the PONAR Wadowice UDZB overflow valve used in lubrication systems. Its aim is to present the phenomena occurring when changing the size of the gap in the valve. The paper contains information on the pressure drop – why does it happen and what its effects may be.

11

Problems of selecting filter partition in passenger car engine intake air filters

Dziubak Tadeusz, Bąkała Leszek

Combustion Engines

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2021

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R. 60, nr 2

44--58

EN

The aim of this study was to verify the criteria for selecting pleated filter partitions used in passenger car engine filters. The paper presents the problem of optimizing pleated air filters in the direction of minimizing pressure drop, which is the source of engine energy losses. Two criteria for selection of a paper filter partition for specific operating conditions of the filter and the engine are presented: criterion of permissible separation speed and criterion of permissible pressure drop. The actual filtration area of 44 paper pleated filter elements used in passenger cars and the air stream flowing through the filter were determined, which made it possible to calculate separation speed. In 62% of the analyzed filter inserts, the calculated separation speeds are within the speed range recommended by the constructors, ʋFmax = 0.06-0.12 m/s. Exceeding permissible separation speed ʋFmax = 0.12 m/s was found mainly in supercharged engines. Negative effects of engine operation with an air filter with too small separation area are presented, in the form of increased pressure drop and energy loss of the engine as well as shorter car mileage to reach permissible pressure drop.

12

Struktura roztworów polimerowo-micelarnych

Malcher Tadeusz

Przemysł Chemiczny

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2020

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T. 99, nr 9

1342--1343

PL

Roztwory polimerowo-micelarne swoje właściwości zmniejszania oporów przepływu zawdzięczają strukturze wewnętrznej. Struktura ta powstaje najczęściej podczas zmieszania roztworu polimerowego z roztworem zawierającym środek powierzchniowo czynny.

EN

Fundamentals and review with 24 refs.

13

Rheological behavior of fly ash suspension with additive for hydraulic conveyance

Kumar K.

International Journal of Applied Mechanics and Engineering

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2020

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Vol. 25, no. 2

202--210

EN

In the present work, rheological behaviour of a fine particulate fly ash slurry suspension is studied with and without addition of an additive. Rheological experiments are performed for the range of shear rate from 50 to 200 s1.Sodium sulfate is used as an additive in the fraction of 0.2, 0.4 and 0.6% (by weight). Addition of sodium sulfate to the fly ash slurry suspension leads to an improvement of its rheological characteristics. A reduction in relative viscosity and pressure drop is more pronounced with the addition of sodium sulfate in proportion of 0.4%, while marginal with 0.2 and 0.6% (by weight). The analysis reveals that the fly ash suspension has a potential to for being transported in a slurry pipeline with higher concentration and minimum energy consumption.

14

Pressure drop reduction in fluid flows with a polymer solution

Edomwonyi-Otu Lawrence Chukwuka

Engineering Transactions

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2020

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Vol. 68, iss. 4

371--383

EN

This work is targeted at making available some data to enhance the development of better predictive models for drag reduction (DR) in two-phase flows. Oil-water flows studies were carried out by using a horizontal acrylic pipe (14 mm ID) with tap water and a middle distillate oil the flowing liquids. A hydrolysed polyacrylamide served as the polymer in the water phase. Polyethylene oxide (PEO) with two different molecular weights was equally investigated. At an optimal polymer concentration of 20 ppm, drag was lowered as Reynolds number increased. While drag reduction was effectively described by models, it increased with polymer weight.

15

Model of forced turbulence for pulsing flow

Dmytriv Vasyl

Diagnostyka

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2020

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Vol. 21, No. 1

89--96

EN

The article deals with fluid motion along an infinite hose. Taking into consideration the Stokes equation, the tangential friction stresses according to Newton and the Reynolds equation, the differential equation of the velocity change in radius is developed taking into account the pulsating component of the friction forces in the turbulent flow. Turbulence is defined as the impulse component of a flow, characterized by a pressure drop along a dynamic length of flow, a frequency response, and an oscillation amplitude of the pressure drop of pulse (which is given by the time equation of the oscillation). The velocity distribution along the radius of the hose in the time interval of one second was modelled for pressure drops in the range from 6000 to 18000 Pa and the amount of transported medium in the range from 1.667·10-5 to 6.667·10-5 m3 , which corresponded to the length of pulse plug. The dynamic viscosity of the medium (milk) of 1.79 · 10-3 Pa·s and its density of 10273 N·s2 /m4 were accounted at the simulation. The developed analytical dependence of the velocity of the forced turbulence of the pulsating flow allows to calculate the absolute value of the velocity at a given point of crosssection of the pipeline, and characterizes the physical process of flow of Newtonian fluids and gases in the pipeline.

16

Study on the Relationship Between Structure Parameters and Filtration Performance of Polypropylene Meltblown Nonwovens

Xiao Yuanxiang, Sakib Nazmus, Yue Zhonghua, Wang Yan, Cheng Si, You Jianmin, Militky Jiri, Venkataraman Mohanapriya, Zhu Guocheng

Autex Research Journal

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2020

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Vol. 20, no. 4

366--371

EN

In this study, polypropylene meltblown nonwoven fabrics with different structure parameters such as fiber diameter, pore size, and areal density were prepared by the industrial production line. The morphology of meltblown nonwoven fibers was evaluated by using scanning electron microscope, and the diameter of fibers was analyzed by using image-pro plus software from at least 200 measurements. The pore size of nonwoven fabric was characterized by a CFP-1500AE type pore size analyzer. The filtration efficiency and pressure drop were evaluated by TSI8130 automatic filter. The results showed that the pressure drop of nonwoven fabrics decreased with the increase in pore size; the filtration efficiency and the pressure drop had a positive correlation with the areal density. However, when the areal density is in the range of 27–29 g/m2, both filtration efficiency and pressure drop decreased with the increase of areal density; when the areal density was kept constant, the filtration efficiency decreased as the pore size decreased; when the pore size of the meltblown nonwoven fabric is less than 17 μm, the filtration efficiency increased as the pore diameter decreased; when the pore diameter of the nonwoven fabric is larger than 17 μm. In a wide range, the pressure drop decreased as the fiber diameter decreased.

17

Numerical investigation and sensitivity analysis of turbulent heat transfer and pressure drop of Al2O3/H2O nanofluid in straight pipe using response surface methodology

Fadodun Olatomide G., Amosun Adebimpe A., Salau Ayodeji O., Olaloye David O., Ogundeji Johnson A., Ibitoye Francis I., Balogun Fatai A.

Archives of Thermodynamics

|

2020

|

Vol. 41, no. 1

3--30

EN

In this paper, investigation of the effect of Reynolds number, nanoparticle volume ratio, nanoparticle diameter and entrance temperature on the convective heat transfer and pressure drop of Al2O3/H2O nanofluid in turbulent flow through a straight pipe was carried out. The study employed a computational fluid dynamic approach using single-phase model and response surface methodology for the design of experiment. The Reynolds average Navier-Stokes equations and energy equation were solved using k-ε turbulent model. The central composite design method was used for the response-surface-methodology. Based on the number of variables and levels, the condition of 30 runs was defined and 30 simulations were performed. New models to evaluate the mean Nusselt number and pressure drop were obtained. Also, the result showed that all the four input variables are statistically significant to the pressure drop while three out of them are significant to the Nusslet number. Furthermore, sensitivity analysis carried out showed that the Reynolds number and volume fraction have a positive sensitivity to both the mean Nusselt number, and pressure drop, while the entrance temperature has negative sensitivities to both.

18

Innovative method for heat transfer enhancement through shell and coil side fluid flow in shell and helical coil heat exchanger

Kumar Rajesh, Chandra Prakash, Prabhansu

Archives of Thermodynamics

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2020

|

Vol. 41, no. 2

239--256

EN

The effect of shell side and coil side volume flow rate on overall heat transfer coefficient, effectiveness, pressure drop and exergy loss of shell and helical coil heat exchanger were studied experimentally under steady state conditions. The working fluid, i.e., water was allowed to flow at three different flow rates of 1, 2, and 3 l/min on shell side (cold water) and at 1, 1.5, 2, 2.5, and 3 l/min on coil side (hot water) for each shell side flow rate at the temperatures of 298±0.4 K and 323±0.4 K, respectively. The results found that the overall heat transfer coefficient increased with increasing both shell side and coil side volume flow rates. The inner Nusselt number significantly increased with the coil side Dean number.

19

Features of hydrates transportation in a fluid flow

Vozniak Lidiia V., Kryvenko Galyna M.

Journal of New Technologies in Environmental Science

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2019

|

Vol. 3, nr 2

84--88

EN

Significant deposits of natural gas are in a gas-hydrated state. One of the options for a possible solution is the transport of hydrates in a fluid flow. The stability of crystalline hydrates, namely, their presence in the solid state, affects both temperature and pressure. The influence of the concentration of solid particles on the reduction or increase of the friction factor is shown, which leads to a decrease or increase in pressure drop during the flow of liquid with solid admixtures. The analytical dependences of the friction factor from the Reynolds number on a certain concentration of solid admixtures in a liquid are proposed A plot of the dependence of the friction factor from the Reynolds number on a certain concentration of rubber crumb and different granulometric composition was constructed.

20

Optimization of compressed heat exchanger efficiency by using genetic algorithm

Ghorbani M., Ranjbar S. F.

International Journal of Applied Mechanics and Engineering

|

2019

|

Vol. 24, no. 2

461--472

EN

Due to the application of coil-shaped coils in a compressed gas flow exchanger and water pipe flow in airconditioner devices, air conditioning and refrigeration systems, both industrial and domestic, need to be optimized to improve exchange capacity of heat exchangers by reducing the pressure drop. Today, due to the reduction of fossil fuel resources and the importance of optimal use of resources, optimization of thermal, mechanical and electrical devices has gained particular importance. Compressed heat exchangers are the devices used in industries, especially oil and petrochemical ones, as well as in power plants. So, in this paper we try to optimize compressed heat exchangers. Variables of the functions or state-of-the-machine parameters are optimized in compressed heat exchangers to achieve maximum thermal efficiency. To do this, it is necessary to provide equations and functions of the compressed heat exchanger relative to the functional variables and then to formulate the parameter for the gas pressure drop of the gas flow through the blades and the heat exchange surface in relation to the heat duty. The heat transfer rate to the gas-side pressure drop is maximized by solving the binary equation system in the genetic algorithm. The results show that using optimization, the heat capacity and the efficiency of the heat exchanger improved by 15% and the pressure drop along the path significantly decreases.