Modeling and Analysis of Iron Mass Transfer Behaviors in Supercritical Boiler Steam-Water System

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Chao Wang ◽  
Hongyuan Li ◽  
Can Chen ◽  
Zilun Zeng ◽  
Hasan Izhar Khan ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Water System ◽  
Mass Transfer Process ◽  
Water Circulation ◽  
Working Fluid ◽  
Circulation System ◽  
Operational Parameters ◽  
Deposition Amount ◽  
Wide Range ◽  
Water Circulation System

Abstract Iron (Fe) concentration is a crucial parameter for boiler safety. However, as the working fluid circulation circuits cross each other, and the working fluid operational parameters change over a wide range, monitoring the Fe content and evaluating pipeline safety are very difficult. The mass transfer process of Fe in a complex water circulation system was described by constructing a network calculation model of Fe mass transfer in the steam-water circulation system of a supercritical boiler. The distribution of Fe and the corrosion/deposition rate in the system was calculated and analyzed. The influence of a Fe mass disturbance in single or multiple equipment on the mass distribution of Fe in the system is discussed. The results show that model calculation data is close to the operational data. Under the effect of cyclic mass transfer, both the granular and dissolved Fe cannot be ignored. During one cycle, about 36% of Fe was deposited on the system tube; however, the deposition amount in the steam generator and superheater section accounted for 81.2% of the total deposition amount, and the rest was deposited in the low-temperature pipeline. The influence of disturbance on other nodes in the network is quite different, which provides the possibility of discriminating the location of the disturbance node. The research results can provide a theoretical reference for water chemical control and safety during the operation.

scholarly journals Mapping of Domestic Hot Water Circulation Losses in Buildings – Preliminary Results from 134 Measurements

2020 ◽  
Vol 172 ◽  
pp. 12009
Author(s):  
Stephen Burke ◽  
Jonatan von Seth ◽  
Tomas Ekström ◽  
Christoffer Maljanovski ◽  
Magnus Wiktorsson
Keyword(s):  
Total Energy ◽  
Energy Flow ◽  
Energy Use ◽  
Average Energy ◽  
Water Circulation ◽  
Hot Water ◽  
Circulation System ◽  
Preliminary Results ◽  
Water Circulation System ◽  
Heated Floor

The hot water circulation system in a building is a system which helps prevent Legionella problems whilst ensuring that tenants have access to hot water quickly. Poorly designed or implemented systems not only increase the risk to people’s health and thermal comfort, but even result in an increase in the energy needed for this system to function properly. Results from previous studies showed that the total hot water circulation system loss can be as high as 25 kWh/m2 heated floor area per year. The purpose of this project is to measure the total energy use per year of the hot water circulation system in about 200 multifamily dwellings of different ages to verify that a system loss of 4 kWh/m2, year is a realistic assumption for both newer and older/retrofitted buildings. The preliminary results from the first 134 measurements showed that the assumption of 4 kWh/m2, year is rarely fulfilled. An average energy use of more than three times this is more common, even in newer buildings. Whilst some of the total energy lost is used to heat the buildings, it is not desirable because it is an uncontrolled energy flow.

scholarly journals The aquarium and sea-water circulation system at the Plymouth Laboratory

1952 ◽  
Vol 31 (1) ◽  
pp. 193-211 ◽  
Author(s):  
Douglas P. Wilson
Keyword(s):  
Natural History ◽  
School Children ◽  
Life Histories ◽  
Sea Water ◽  
Water Circulation ◽  
Circulation System ◽  
Marine Animals ◽  
Public Display ◽  
Water Circulation System ◽  
Small Charge

The aquarium or tank room, to which visitors are admitted on payment of a small charge, was not designed primarily for public display, but was intended principally to facilitate scientific observations on the habits and life histories of marine animals. This original purpose it has never lost, but of recent years it has increasingly catered also for the steadily growing number of people interested in natural history, and for numerous classes of school-children brought by their teachers. Since the aquarium was re-opened in November 1946 attendances have shown a big increase over comparable pre-war figures.

Influence of operational parameters on performance of twin thermoacoustic prime mover – CFD studies

2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Jabbar P ◽  
Hariharan N.M ◽  
Palani Sivashanmugam ◽  
S. Kasthurirengan
Keyword(s):  
Temperature Gradient ◽  
Design Methodology ◽  
Cfd Simulation ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Pressure Amplitude ◽  
Prime Mover ◽  
Operational Parameters ◽  
Fluid Medium ◽  
Wide Range

Purpose The present investigation deals with the analysis of the performance of twin thermoacoustic prime mover (TAPM) which are measured in terms of frequency and pressure amplitude by varying the parameters such as temperature gradient along the length of stack and the operating pressures of fluid medium argon using CFD simulation. With the help of CFD researchers and Engineers can evaluate the performance of a wide range of thermoacoustic systems on the computer without the time, expense, and disruption required to make actual changes onsite (stack) which is tedious to fabricate. Design/methodology/approach For the present simulation, the operating pressures of argon such as 1bar, 3bar and 5bar, and the temperature gradient is varied from 600K to 1400K with the regular intervals of each 200K. The geometry of twin TAPM is created using GAMBIT processor, and the simulation is carried out using FLUENT. The geometrical parameters of twin TAPM are kept constant throughout the simulation. The results for frequency and pressure amplitude obtained from the CFD simulation of twin TAPM for various temperature gradient and operating pressures are analysed and reported. Findings The computational results of twin thermoacoustic prime mover shows an increase in pressure amplitude with an increase in the temperature gradient and also it increases with an increase in operating pressures of the fluid medium. The parameter operating pressures of the working fluid medium and the stack hot end temperature has no significant effect on the output, frequency. Originality/value Though several experimental works had been published based on the twin thermoacoustic prime mover, an attempt has been made in the present investigation for the first time to estimate the performance of twin thermoacoustic prime mover using CFD package (ANSYS-FLUENT) by varying temperature gradient. The temperature gradient and operating pressures were varied and the performance of twin thermoacoustic prime mover was measured in terms of frequency and pressure amplitude.

scholarly journals Preliminary analysis of geological disaster and water circulation system

2020 ◽  
Vol 194 ◽  
pp. 04031
Author(s):  
Yubin Zhang
Keyword(s):  
Natural Environment ◽  
Water Environment ◽  
The United States ◽  
Water Circulation ◽  
Circulation System ◽  
Great Loss ◽  
Geological Disasters ◽  
Geological Disaster ◽  
Water Circulation System ◽  
Improvement Programs

China is a country with frequent geological disasters. First of all, the occurrence of geological disaster will cause great loss of life and property. Secondly, disasters cause changes in topography and landforms, which also have an impact on the natural environment. In a sense, the occurrence of geological disasters and the natural environment are mutually affected. The occurrence of geological disasters is closely related to the soil and water environment. The improvement of regional water circulation system can obviously reduce the occurrence of geological disasters. This paper analyzes the causes of geological disasters. This paper introduces the water environment improvement programs in the United States, Britain and China.

PENGARUH PERBEDAAN WARNA WADAH TERHADAP SINTASAN DAN PERTUMBUHAN LARVA IKAN BAUNG (Hemibagrus nemurus Blkr)

2007 ◽  
Vol 2 (3) ◽  
pp. 425
Author(s):  
Yosmaniar Yosmaniar ◽  
Imam Taufik ◽  
Sutrisno Sutrisno
Keyword(s):  
Artemia Salina ◽  
Water Circulation ◽  
Water Volume ◽  
Circulation System ◽  
Research Station ◽  
Water Circulation System ◽  
Survival And Growth ◽  
Ad Libitum ◽  
Tank Colour

Penelitian warna wadah dilakukan untuk mengetahui pengaruhnya terhadap sintasan dan pertumbuhan larva ikan Baung (Hemibagrus nemurus Blkr.). Penelitian dilakukan di Instalasi Riset Lingkungan Perikanan Budidaya dan Toksikologi Cibalagung, Bogor. Wadah yang digunakan berupa 24 unit akuarium berukuran 70 cm x 40 cm x 45 cm yang diisi air sebanyak 40 L dan dilengkapi aerasi sistem sikulasi air. Hewan uji yang digunakan adalah larva ikan baung umur 1 hari yang ditebar dengan kepadatan10 ekor/L dan diberi pakan alami, yaitu artemia (ad libitum) dan dilanjutkan dengan cacing sutra (at satiation). Perlakuan berupa perbedaan warna wadah, yaitu: kontrol, merah kuning, dan biru. Waktu penelitian selama 21 hari. Hasil penelitian menunjukkan warna wadah tidak berpengaruh terhadap sintasan (18,96%; 19,12%; 18,18%; 10,50%) maupun pertumbuhan.The main purpose of this experiment was know the effect of tank colour differences on survival and growth of catfish(Hemibagrus nemurus Blkr) larvae . The experiment was conducted at Research Station Culture Fishery and Toxicology Cibalagung, Bogor. Twenty four aquaria of 70 cm x40 cm x45 cm in size with 40 L water volume were used in this experiment completed with water circulation system. Each aquarium was stocked with 10 larvae/L of catfish of one day old. The larvae was feed with Artemia salina (ad libitum) and continued with Tubifex (at satiation). Four different tank colour of aquaria were applied i.e control, red, yellow, and blue. Larvae were reared up 21 days. The result showed that colour of aqauaria wee not significantly different on and growth.

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