scholarly journals Feasibility of Boosting Low-Energy-Quality Steam by Using Wave Rotor

2021 ◽  
Vol 2097 (1) ◽  
pp. 012018
Author(s):  
Yuqiang Dai ◽  
Zhipeng Tang ◽  
Mohan Li ◽  
Gang Hao ◽  
Luwei Zhang ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Low Pressure ◽  
Low Energy ◽  
Saturated Steam ◽  
Wave Rotor ◽  
Entrainment Ratio ◽  
Novel Technology ◽  
Steam Ejector ◽  
Pressure Steam

Abstract Owing to the difficult utilization of the low-pressure level in the process industry, the low-energy-quality steam is often condensed to recover the demineralized water or just discharged directly, causing a huge waste of thermal energy. A novel technology of enhancing the steam’s energy quality by using the wave rotor based on the principle of moving shockwave compression is proposed. The supercharging ability of 3-port wave rotor is studied by meaning of 1-dimension unsteady theory and computational fluid dynamic. A practical thermodynamic flowsheet of boosting the low-pressure steam driven by high-pressure steam is also proposed and analysed in detail. As an example, to boost the saturated steam of pressure 1.0 MPa to 1.953 MPa, a three-stage wave rotor solution is proposed and is verified its feasibility. The high supercharging ratio and entrainment ratio of the wave rotor are much higher than the traditional steam ejector shows the feasibility of enhancing energy-quality of low-pressure steam.

scholarly journals Potential of Steam Recovery from Excess Steam in Sterilizer at Palm Oil Mill

2020 ◽  
Vol 79 (1) ◽  
pp. 17-26
Author(s):  
Yoganathan Palaniandy ◽  
Nor Mariah Adam ◽  
Yiu Pang Hung ◽  
Fatin Hana Naning
Keyword(s):  
Energy Consumption ◽  
Palm Oil ◽  
Low Pressure ◽  
Boiler Fuel ◽  
Total Energy Consumption ◽  
Process Plant ◽  
Steam Ejector ◽  
Pressure Steam ◽  
Palm Oil Mill ◽  
The Cost

Energy saving is something that being focus deeply either larger or smaller industry in this current era especially steam and electricity. In a crude palm oil mill, tons of fibers and woods are used for burning process as a boiler fuel to generate steam. As steam is good heat transfer medium, it is use for the regular process of heating the product or materials by direct and batch heating to raise the temperature in order to change the characteristic. In typical palm oil mill, every 1000kg of fresh fruits bunches (FFB) required 250kg of steam energy for the sterilization process. It is not surprising that the exhaust lost that release to the atmosphere from the total steam usage is about 70%, which can conclude as energy waste. By referring to this issue, the cost of replace consumable boiler fuel increase tremendously. Besides that, the huge amount of heat release caused the thermal pollution that may have significant effects in the ecological balance and lead to changes in the aquatic fauna and flora. This paper reviews and critically discusses the waste of steam energy and the morphology involved in excess steam from sterilizer. The system that combined with few steps of steam recovery were developed to recovery the low-pressure steam to form the mid-pressure steam that can able to reuse at the process plant. The steam ejector technology is use in this research to recover and reuse the excess steam leading to lower energy consumption and fuel costs. The overall idea is about combining the low-pressure excess steam with high-pressure steam that directly supply from back pressure receiver to form the mid-pressure steam. The Ansys software used as to identify the change of parameter of excess steam and through the software, the percentage of motive steam needed to combine with excess steam finalized. Via recovery and reuse the excess steam from sterilizer, the total energy consumption will be minimized at least 20% which can able to reduce the massive expenses for boiler fuel that benefit the palm oil mill owners.

scholarly journals Investigation on low-pressure steam turbine exhaust hood modelling through computational fluid dynamic simulations

2019 ◽  
Author(s):  
Tommaso Fondelli ◽  
Tommaso Diurno ◽  
Lorenzo Palanti ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Low Pressure ◽  
Exhaust Hood ◽  
Dynamic Simulations ◽  
Pressure Steam ◽  
Turbine Exhaust

scholarly journals Analisa Variasi Tekanan Fluida Primer, Tekanan Discharge dan Posisi Keluaran Nozzle (NXP) pada Steam Ejector Menggunakan Metode Computational Fluid Dynamic (CFD)

ROTASI ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 120
Author(s):  
MSK Tony Suryo Utomo ◽  
Susilo Adi Widyanto ◽  
Abibrojo Sekar
Keyword(s):  
Computational Fluid Dynamic ◽  
Critical Pressure ◽  
Fluid Dynamic ◽  
Entrainment Ratio ◽  
Steam Ejector

Dilakukan simulasi numerik steam ejector dengan memvariasikan tekanan dari fluida primer, tekanan discharge dan posisi keluaran nozzle (NXP). Perlakuan variasi tekanan fluida primer dan tekanan discharge dilakukan untuk mendapat nilai nilai performa steam ejector yang disebut entrainment ratio (ER), tekanan kritis (critical pressure) dan tekanan discharge maksimum. Perlakuan variasi NXP dilakukan untuk mengetahui posisi keluaran nozzle terbaik dari steam ejector dengan nilai ER yang paling tinggi. Tekanan fluida primer yang divariasikan yaitu 2.66 bar, 3.00 bar dan 3.50 bar. Tekanan discharge divariasikan dari 0.20 bar sampai ejector mengalami aliran balik. NXP yang divariasikan yaitu dari posisi -3 mm atau -0.11 Den sampai + 35 mm atau 1.3 Den. Hasil simulasi menunjukkan bahwa kenaikan tekanan fluida primer menyebabkan naiknya critical pressure tetapi membuat nilai entrainment ratio turun. Kenaikan tekanan discharge menyebabkan turunnya jarak shockwave ke posisi keluaran nozzle. Shockwave tercipta karena kenaikan tekanan yang signifikan secara cepat, saat tekanan discharge mendekati nilai critical pressure menunjukkan shockwave yang semakin lemah. Hasil variasi NXP dari posisi -3 mm ke +35 mm menunjukkan kenaikan dan penurunan dari entrainment ratio, posisi NXP + 19 mm atau 0.7 Den menunjukkan nilai ER paling besar sedangkan posisi NXP -3 mm paling kecil. Fluida yang dimodelkan ialah gas ideal dengan asumsi fluida berada pada kondisi saturasi uap. Pemodelan aliran menggunakan k- standard untuk memodelkan aliran dengan nilai Re yang tinggi dan dapat menerapkan perlakuan dinding agar hasil yang didapat akurat. Pemodelan geometri dibuat dengan menggunakan software CAD yaitu Solidworks 2015, geometri dieksport ke Ansys 16.2 dan di meshing dengan perlakuan adapsi y+.

Electrical Damage Due to Low Energy Plasma Processing of GaAs Structures

1991 ◽  
Vol 223 ◽  
Author(s):  
Hans P. Zappe ◽  
Gudrun Kaufel
Keyword(s):  
Chemical Processes ◽  
Low Energy ◽  
Electrical Behavior ◽  
Rapid Thermal Anneal ◽  
High Temperature Anneal ◽  
Significant Damage ◽  
Low Energies ◽  
Long Time ◽  
Physical Plasma

ABSTRACTThe effect of numerous plasma reative ion etch and physical milling processes on the electrical behavior of GaAs bulk substrates has been investigated by means of electric microwave absorption. It was seen that plasma treatments at quite low energies may significantly affect the electrical quality of the etched semiconductor. Predominantly physical plasma etchants (Ar) were seen to create significant damage at very low energies. Chemical processes (involving Cl or F), while somewhat less pernicious, also gave rise to electrical substrate damage, the effect greater for hydrogenic ambients. Whereas rapid thermal anneal treatments tend to worsen the electrical integrity, some substrates respond positively to long-time high temperature anneal steps.

Dynamic Viscosity of Compressed Water to 10 Kilobar and Steam to 1500°C

1969 ◽  
Vol 11 (2) ◽  
pp. 189-205 ◽  
Author(s):  
E. A. Bruges ◽  
M. R. Gibson
Keyword(s):  
Gaseous Phase ◽  
Dynamic Viscosity ◽  
Low Temperatures ◽  
Pressure Range ◽  
Low Pressure ◽  
Temperature Range ◽  
Inversion Temperature ◽  
Pressure Steam ◽  
Correlating Equations ◽  
First Time

Equations specifying the dynamic viscosity of compressed water and steam are presented. In the temperature range 0-100cC the location of the inversion locus (mu) is defined for the first time with some precision. The low pressure steam results are re-correlated and a higher inversion temperature is indicated than that previously accepted. From 100 to 600°C values of viscosity are derived up to 3·5 kilobar and between 600 and 1500°C up to 1 kilobar. All the original observations in the gaseous phase have been corrected to a consistent set of densities and deviation plots for all the new correlations are given. Although the equations give values within the tolerances of the International Skeleton Table it is clear that the range and tolerances of the latter could with some advantage be revised to give twice the existing temperature range and over 10 times the existing pressure range at low temperatures. A list of the observations used and their deviations from the correlating equations is available as a separate publication.

scholarly journals Numerical Investigation of the Effect of Air Leaking into the Working Fluid on the Performance of a Steam Ejector

2021 ◽  
Vol 11 (13) ◽  
pp. 6111
Author(s):  
He Li ◽  
Xiaodong Wang ◽  
Jiuxin Ning ◽  
Pengfei Zhang ◽  
Hailong Huang
Keyword(s):  
Flow Structure ◽  
Mass Fraction ◽  
Internal Flow ◽  
Working Fluid ◽  
Physical Parameters ◽  
Entrainment Ratio ◽  
Air Mass ◽  
Steam Ejector ◽  
Primary Fluid ◽  
Mass Fractions

This paper investigated the effect of air leaking into the working fluid on the performance of a steam ejector. A simulation of the mixing of air into the primary and secondary fluids was performed using CFD. The effects of air with a 0, 0.1, 0.3 and 0.5 mass fraction on the entrainment ratio and internal flow structure of the steam ejector were studied, and the coefficient distortion rates for the entrainment ratios under these air mass fractions were calculated. The results demonstrated that the air modified the physical parameters of the working fluid, which is the main reason for changes in the entrainment ratio and internal flow structure. The calculation of the coefficient distortion rate of the entrainment ratio illustrated that the air in the primary fluid has a more significant impact on the change in the entrainment ratio than that in the secondary fluid under the same air mass fraction. Therefore, the air mass fraction in the working fluid must be minimized to acquire a precise entrainment ratio. Furthermore, this paper provided a method of inspecting air leakage in the experimental steam ejector refrigeration system.

scholarly journals A novel p-harmonic descent approach applied to fluid dynamic shape optimization

2021 ◽  
Author(s):  
Peter Marvin Müller ◽  
Niklas Kühl ◽  
Martin Siebenborn ◽  
Klaus Deckelnick ◽  
Michael Hinze ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Large Deformations ◽  
Fluid Dynamic ◽  
Shape Optimisation ◽  
Shape Features ◽  
Floating Bodies ◽  
Novel Method ◽  
Sharp Corners ◽  
Dynamic Shape

AbstractWe introduce a novel method for the implementation of shape optimization for non-parameterized shapes in fluid dynamics applications, where we propose to use the shape derivative to determine deformation fields with the help of the $$p-$$ p - Laplacian for $$p > 2$$ p > 2 . This approach is closely related to the computation of steepest descent directions of the shape functional in the $$W^{1,\infty }-$$ W 1 , ∞ - topology and refers to the recent publication Deckelnick et al. (A novel $$W^{1,\infty}$$ W 1 , ∞ approach to shape optimisation with Lipschitz domains, 2021), where this idea is proposed. Our approach is demonstrated for shape optimization related to drag-minimal free floating bodies. The method is validated against existing approaches with respect to convergence of the optimization algorithm, the obtained shape, and regarding the quality of the computational grid after large deformations. Our numerical results strongly indicate that shape optimization related to the $$W^{1,\infty }$$ W 1 , ∞ -topology—though numerically more demanding—seems to be superior over the classical approaches invoking Hilbert space methods, concerning the convergence, the obtained shapes and the mesh quality after large deformations, in particular when the optimal shape features sharp corners.

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