Applied sciences

Archives of Thermodynamics

Content

Archives of Thermodynamics | 2021 | vol. 42 | No 1

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Abstract

This paper presents the results of experimental research regarding the determination of the flow characteristics of the compressor of an automotive turbocharger with a plastic rotor disc. The disc was manufactured using the 3D printing technology called the multijet printing, which allows complex geometries to be printed with high precision. Currently, in addition to speeding up the manufacturing processes and reducing their costs, 3D printing technologies are increasingly seen as standard tools that can be used in the design and optimization of machine parts. This article is a continuation of research on the possibility of applying additively manufactured elements in turbomachines. The experimental research was carried out at high rotational speeds (up to 110 000 rpm), using the automotive turbocharger with two different compressor rotors (i.e. one aluminum and one polymer). The first chapters of the paper discuss the preparation stage of the research (i.e. the manufacture of the rotor, the test rig). Then, the experimental research and the flow characteristics are described. The results obtained for the two types of discs were compared with each other and the area of application of the additively manufactured rotor was determined. The rotor functioned properly in the range of tested operating parameters and the results obtained showed that the technology and material applied could be used in the optimization studies of the blade systems of high-speed fluid-flow machines.
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Authors and Affiliations

Artur Andrearczyk
1

  1. Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk, Poland
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Abstract

In most production plants, waste heat is usually discharged into the environment, contributing to a reduction in the energy efficiency of industrial processes. This is often due to the low thermal parameters of the carriers in which this energy is contained, such as oils, water, exhaust gases or other post-process gases, which means that their use for electricity production in a conventional Rankine cycle may prove to be economically unprofitable. One of the technologies enabling the use of lowand medium-temperature waste heat carriers is the organic Rankine cycle (ORC) technology. The paper present results of calculations performed to evaluate potential electricity production in ORC using waste heat from a natural gas-fired glass melting furnace. The analysis was carried out assuming the use of a single-stage axial turbine, whose efficiency was estimated using correlations available in the literature. The calculations were carried out for three working fluids, namely hexamethyldisiloxane, dimethyl carbonate, and toluene for two scenarios, i.e. ORC system dedicated only to electricity production and ORC system working in cogeneration mode, where heat is obtain from cooling the condenser. In each of the considered cases, the ORC system achieves the net power output exceeding 300 kW (309 kW for megawatts in the cogenerative mode to 367 kW for toluene in the non-cogenerative mode), with an estimated turbine efficiency above 80%, in range of 80,75 to 83,78%. The efficiency of the ORC system, depending on the used working fluid and the adopted scenario, is in the range from 14.85 to 16.68%, achieving higher efficiency for the non-cogenerative work scenario.
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Authors and Affiliations

Arkadiusz Mateusz Musiał
1 2
Łukasz Antczak
1
Łukasz Jedrzejewski
3
Piotr Klonowicz
3

  1. Marani Sp. z o.o., Szybowa 14c, 41-808 Zabrze, Poland
  2. Silesian University of Technology, Akademicka 2A, 44-100 Gliwice, Poland
  3. Institute of Fluid Flow Machinery Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk, Poland
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Abstract

This paper analyses the influence of three different ring-type inlet duct geometries on the performance of a small 1 MW backpressure steam turbine. It examines the efficiency and pressure drop of seven turbine variants, including four spiral inlet geometries and three stages with a mass flow rate around 30 t/h. A one-pipe and two-pipe inlets are analysed from aerodynamical point of view, taking into account stator and rotor blades in three stages without the outlet. An outlet is added to the best variant. Also analysed is the occurrence of vortices in the inlets of the studied variants 1–7 as well as the efficiency, drop pressure, turbine power and mass flow. Finally, the best inlet for a 1 MW steam turbine is suggested.
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Authors and Affiliations

Arkadiusz Koprowski
1
Romuald Rzadkowski
1 2

  1. Institute of Fluid Flow Machinery Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk, Poland
  2. Air Force Institute of Technology, Ksiecia Bolesława 6, 01-494 Warsaw, Poland
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Abstract

This paper presents the design method and the construction details of a subsonic low-speed wind tunnel, which has been designed to achieve the flow velocity of 35 m/s in the measurement section with expected uniform velocity field at its inlet. To achieve such objectives a very detailed design was performed using a theoretical 1D analysis and computational fluid dynamics simulations. This approach was applied to improve the flow quality along the wind tunnel sections. When the wind tunnel has been launched a direct comparison of the experimentally measured flow field in the test section and numerical simulation results was conducted. Such comparison of the simulation results with the experimental one is presented in this paper. The obtained results confirm that assumed wind tunnel design method was correct, i.e. the pressure drop in the wind tunnel has been predicted very well and drive system is effective and sufficient to accelerate the airflow to required values.
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Authors and Affiliations

Ryszard Szwaba
1
Krzysztof Hinc
1
Tomasz Ochrymiuk
1
Zbigniew Krzemianowski
1
Piotr Doerffer
1
Marcin Kurowski
1

  1. Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk, Poland
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Abstract

The work presents a numerical investigation for the convective heat transfer of nanofluids under a laminar flow inside a straight tube. Different models applied to investigate the improvement in convective heat transfer, and Nusselt number in comparison with the experimental data. The impact of temperature dependence, temperature independence, and Brownian motion, was studied through the used models. In addition, temperature distribution and velocity field discussed through the presented models. Various concentrations of nanoparticles are used to explore the results of each equation with more precision. It was shown that achieving the solution through specific models could provide better consistency between obtained results and experimental data than the others.
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Authors and Affiliations

Farqad Rasheed Saeed
1
Marwah Abdulkareem Al-Dulaimi

  1. Ministry of Science and Technology, Directorate of Materials Research, 55509 Al-Jadriya, Iraq
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Abstract

The results of a systematic study of the influence of meridional contours overlap in the stator-rotor axial interspace of the impulse and reactive type stages of a high-pressure steam turbine on the flow structure and gas-dynamic efficiency of the flow part are introduced. The studied flow parts of the impulse and reactive stages are typical for high-power high-pressure steam turbines. It is shown that the stages that have no overlaps and/or have a smooth shape of meridional contours have the best gasdynamic efficiency, and the most negative effect on the flow part is caused by the presence of caverns in the stator-rotor interspace. For cases where, due to technological limitations, it is impossible to avoid the presence of caverns and overlaps with a sharp (step-wise) change in the shape of the meridional contours, it is recommended to perform overlaps with positive size of overlap values near the rotor blades.
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Authors and Affiliations

Andrii Rusanov
1
Roman Rusanov
1

  1. The A. N. Pidgorny Institute of Mechanical Engineering Problems NAS of Ukraine, Dm. Pozharsky 2/10, 61046 Kharkiv, Ukraine
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Abstract

Solar cell performance decreases with increasing temperature, heat can reduce output efficiency by 10–25%. The operating temperature plays a key role in the photovoltaic conversion process. Increase in electrical efficiency depends on cooling techniques, in particular photovoltaic modules installed in the high temperature regions. A cooling process using a single nozzle of photovoltaic panel operating under different configurations was simulated. The simulation contains two parts: the first is a thermodynamic investigation of fluid impingement upon the sensor front face. The second is a performance comparison between two types of glass cover. The major result that emerges from this simulation is the effect of a single nozzle arrangement to enhance the cooling process, under a low cadence of impinging droplets in the range 0.1–1.7 m/s.
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Authors and Affiliations

Hocine Mzad
1
Abdessalam Otmani
1

  1. Mechanical Engineering Department, Badji Mokhtar University of Annaba, P.O. Box 12, DZ-23000, Algeria
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Abstract

Application of retractable enclosures enables to lengthen operation periods for outdoor swimming pools operated in the moderate climate zone. Enclosures allow to diminish energy losses from water in the pool to the environment. Thermal calculations for pools with retractable enclosures are difficult to carry out because of a number of required parameters which can only be estimated. One of them is the transmission of solar radiation through the enclosure. The present paper presents the method of estimation of this parameter for swimming pool enclosures made of polycarbonate panels that have multichannels structure. In order to calculate transmission, the methodology considering the multiples of solar reflection inside the enclosure and their absorption by polycarbonate has been elaborated. Calculation results for transmission of the enclosure were verified experimentally. Analysis of results show that the transmission depends strongly on the enclosure’s construction and on the direction of solar radiation on the enclosure. Mean transmission values of enclosure under research were determined both from calculations and experiment are equal to about 0.69 and 0.64, respectively. However, experimentally determined mean values of total transmission by parallel and perpendicular solar directions in relation to channel axes are equal to about 0.69 and 0.60, respectively.
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Authors and Affiliations

Zbigniew Zapałowicz
1
Agnieszka Garnysz-Rachtan
1

  1. West Pomeranian University of Technology in Szczecin, Faculty of Mechanical Engineering and Mechatronics, Department of Energy Technologies, Al. Piastów 19, 70-310 Szczecin, Poland
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Abstract

Energy demand is increasing exponentially in the last decade. To meet such demand there is an urgent need to enhance the power generation capacity of the electrical power generation system worldwide. A combined- cycle gas turbines power plant is an alternative to replace the existing steam/gas electric power plants. The present study is an attempt to investigate the effect of different parameters to optimize the performance of the combined cycle power plant. The input physical parameters such as pressure ratio, air fuel ratio and a fraction of combustible product to heat recovery heat exchanger via gas turbine were varied to determine the work output, thermal efficiency, and exergy destruction. The result of the present study shows that for maximum work output, thermal efficiency as well as total exergy destruction, extraction of combustible gases from the passage of the combustion chamber and gas turbine for heat recovery steam generator is not favorable. Work output and thermal efficiency increase with an increase in pressure ratio and decrease in air fuel ratio but for minimum total exergy destruction, the pressure ratio should be minimum and air fuel ratio should be maximum.
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Authors and Affiliations

Mohammad Nadeem Khan
1

  1. Department of Mechanical and Industrial Engineering, College of Engineering, Majmaah University, Majmaah 11952, Saudi Arabia
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Abstract

Hybrid nanofluids is obtained by dispersing more than one nanoparticle into a base fluid. The work is concerned with a detailed numerical investigation of the thermal efficiency and hydraulic performance of hybrid nanofluids for circular jet impinges on a round plate. For this paper, a metal (Ag), a metal oxides (Al2O3) and a metal carbides (SiC) nanoparticle and their water based hybrid nanofluids are considered to analyse numerically with varying significant dimensionless parameters, i.e., the jet-to-plate spacing ratio, Reynolds number and volume fraction of nanoparticles. The results demonstrated that the efficiency of heat transfer of all nanofluids is increased by the addition of nanoparticle to the dispersed in water at constant Reynolds number. Moreover, the results illustrate that heat transfer efficacy and pumping power penalty both increased as jet-to-plate spacing ratio reduced. The jet-to-plate spacing ratio equal to 4 is the best as the percentage enhance heat transfer is maximum in this situation. Since both the heat transfer effect and pumping penalty increase using hybrid nanofluids, thermal performance factor increases or decreases depends on nanoparticles of nanofluids. It is evident that the analysis of these hybrid nanofluids will consider both the increase in heat efficiency and the pumping capacity. The best flow behaviour is achieved for SiC–Al2O3 hybrid nanofluids. New merit number is introduced for additional clarification.
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Authors and Affiliations

Abanti Datta
1
Pabitra Halder
1

  1. Indian Institute of Engineering Science and Technology, Shibpur PO: Botanic Garden, Howrah-711103, West Bengal, India
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Abstract

Based on the exergetic sustainability indicators of polymer electrolyte membrane (PEM) fuel cell, this paper studied the effects of irreversibility of thermodynamics on some exergetic sustainability indicators of PEM fuel cell under changing operating temperature, operating pressure and current density. Some conclusions are drawn by analyzing the curves. As the operating temperature increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; As the operating pressure increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; On the other hand, with the increase of current density, the negative impact of the PEM fuel cell on various parameters due to irreversibility increases.
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Authors and Affiliations

Bing Xu
1
Yan Chen
2
Zheshu Ma
1

  1. Nanjing Forestry University Coll Automobile & Traff Engn, Nanjing 210037, Jiangsu, China
  2. The 723th Institute, China Shipbuilding Industry Corporation, Yangzhou, 225001, China

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Journal citation (APA – 7th ed):
[1] Król, J., & Ocłoń, P. (2019). Sensitivity analysis of hybrid combined heat and power plant on fuel and CO2 emission allowances price change. Energy Conversion and Management, 196, 127–148.
doi.org/10.1016/j.enconman.2019.05.090

[2] Zhou, Y., Bi, H., & Wang, H. (2023). Influence of the primary components of the high-speed train on fire heat release rate. Archives of Thermodynamics, 44(1), 37–61.
doi.org/10.24425/ather.2023.145876

When citing scientific papers, it is needed to provide a DOI identifier if available.
Example of citation:
• Król and Ocłoń [1] studied a hybrid CHP sensitivity on fuel and CO2 emission allowances price change.
• Zhou et al. [2] studied the influence of the primary components of the high speed train on fire heat release rate.

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[3] Ocłoń, P. (2021). Renewable energy utilization using underground energy systems (1st ed.). Springer Nature.
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• Ocłoń et al. [3] presented renewable energy systems for heating cooling and electrical energy production in buildings.

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[4] Ciałkowski, M., & Frąckowiak, A. (2014). Boundary element method in inverse heat conduction problem. In Encyclopedia of Thermal Stresses (pp. 424–433). Springer Netherlands.
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[5] Pourghasemi, B., & Fathi, N. (2023). Validation and verification analyses of turbulent forced convection of Na and NaK in miniature heat sinks. ASME 2023 Verification, Validation, and Uncertainty Quantification Symposium, 17-19 May, Baltimore, USA.
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• Pourghasemi and Fathi [5] validated and verified turbulent forced convection of Na and NaK in miniature heat sinks.
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