Heat Coupling of Gasoline Upgrading and Fluid Catalytic Cracking Processes

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Xingying Lan ◽  
Chunming Xu ◽  
Gang Wang ◽  
Jian Chang ◽  
Chunxi Lu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Balance ◽  
Cfd Simulation ◽  
Flow Behavior ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Regeneration System ◽  
Fcc Gasoline ◽  
Fcc Catalysts ◽  
The Heat Balance

Heat supplement is necessary for FCC gasoline upgrading processes to keep the heat balance of reaction-regeneration system, while excess heat would be removed in FCC process due to the processing of heavy feedstock. Combining gasoline upgrading processes with FCC process can realize the heat coupling so as to achieve the maximum energy utilization. In this paper, the heat balance calculations of a commercial FCC unit and a FCC gasoline aromatization process were carried out, and the feasibility as well as the way to accomplish the heat coupling for the two processes was investigated. The results showed that the coked aromatization catalysts could be heated to the desired temperature by the direct contact with the hot regenerated FCC catalysts. The pilot experiment and CFD simulation was carried out to investigate the flow behavior and heat transfer of the direct coupling system of FCC process and FCC gasoline aromatization process. The results indicated that the well-mixing and efficient heat transfer between FCC catalysts and aromatization catalysts, as well as the sufficient regeneration of aromatization catalysts, could be achieved at appropriate operating conditions.

Analysis of the Cooling Concept of the Braking System of a Formula Student Racing Car Using CFD Simulation and 1D Simulation

2021 ◽  
Vol 412 ◽  
pp. 115-129
Author(s):  
Rainer Stauch ◽  
Jens Bög ◽  
Stefan Grabant ◽  
Robin König ◽  
Dominic Traub
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Heat Balance ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Thermal Design ◽  
Brake Disc ◽  
Transfer Coefficients ◽  
Braking System ◽  
The Heat Balance

In order to guarantee the performant operation of the braking system of a racing car under high load an optimized thermal design of the braking system is an important factor. Especially in motorsports, a lot of braking energy is converted into heat due to short and intense braking events. Therefore, a suitable cooling concept is a crucial point to ensure a reliable thermal management of the braking system to dissipate the generated heat. In this work, the braking system of the formula student racing car of the UAS Esslingen is analysed using the racing car of the season 2019. A transient 1D simulation model of the heat balance of the braking system is created. For the determination of the heat transfer coefficients a steady 3D Conjugate Heat Transfer (CHT) simulation model is set up. The logging data of a real race are used for the validation of the presented model (s). The heat balance of the braking system, its entire heat flows as well as the time-dependent temperature evaluation of the brake disc are analysed and compared. The results of this analysis are used to create a cooling concept for the racing car’s braking system, to ensure an optimized braking performance over the entire race. Several different (geometrical) variants of the thermal design of the braking system are investigated using the above mentioned numerical models and the results are presented. Furthermore, the implementation of a cooling duct for the braking system is studied.

Calculation of Hourly Output of a Solar Still

1993 ◽  
Vol 115 (4) ◽  
pp. 231-236 ◽  
Author(s):  
V. B. Sharma ◽  
S. C. Mullick
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Balance ◽  
Solar Still ◽  
Balance Equations ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Hourly Output ◽  
The Heat Balance

An approximate method for calculation of the hourly output of a solar still over a 24-hour cycle has been studied. The hourly performance of a solar still is predicted given the values of the insolation, ambient temperature, wind heat-transfer coefficient, water depth, and the heat-transfer coefficient through base and sides. The proposed method does not require graphical constructions and does not assume constant heat-transfer coefficients as in the previous methods. The possibility of using the values of the heat-transfer coefficients for the preceding time interval in the heat balance equations is examined. In fact, two variants of the basic method of calculation are examined. The hourly rate of evaporation is obtained. The results are compared to those obtained by numerical solution of the complete set of heat balance equations. The errors from the approximate method in prediction of the 24-hour output are within ±1.5 percent of the values from the numerical solution using the heat balance equations. The range of variables covered is 5 to 15 cms in water depth, 0 to 3 W/m2K in a heat-transfer coefficient through base and sides, and 5 to 40 W/m2K in a wind heat-transfer coefficient.

scholarly journals Multi-Scale CFD Modeling of Plate Heat Exchangers Including Offset-Strip Fins and Dimple-Type Turbulators for Automotive Applications

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2965 ◽  
Author(s):  
Augusto Della Torre ◽  
Gianluca Montenegro ◽  
Angelo Onorati ◽  
Sumit Khadilkar ◽  
Roberto Icarelli
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Heat Exchangers ◽  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Full Scale ◽  
Operating Conditions ◽  
Plate Heat ◽  
Multi Scale ◽  
Macro Scale

Plate heat exchangers including offset-strip fins or dimple-type turbulators have a wide application in the automotive field as oil coolers for internal combustion engines and transmissions. Their optimization is a complex task since it requires targeting different objectives: High compactness, low pressure drop and high heat-transfer efficiency. In this context, the availability of accurate Computational Fluid Dynamics (CFD) simulation models plays an important role during the design phase. In this work, the development of a computational framework for the CFD simulation of compact oil-to-liquid heat exchangers, including offset-strip fins and dimples, is presented. The paper addresses the modeling problem at different scales, ranging from the characteristic size of the turbulator geometry (typically µm–mm) to the full scale of the overall device (typically cm–dm). The simulation framework is based on multi-scale concept, which applies: (a) Detailed simulations for the characterization of the micro-scale properties of the turbulator, (b) an upscaling approach to derive suitable macro-scale models for the turbulators and (c) full-scale simulations of the entire cooler, including the porous models derived for the smaller scales. The model is validated comparing with experimental data under different operating conditions. Then, it is adopted to investigate the details of the fluid dynamics and heat-transfer process, providing guidelines for the optimization of the device.

CFD Simulation of Wall-Bounded Laminar Flow Through Screens: Part II — Mixing Characterization

2020 ◽  
Author(s):  
W. Abou Hweij ◽  
F. Azizi
Keyword(s):  
Cfd Simulation ◽  
Flow Behavior ◽  
Particle Method ◽  
Immiscible Fluids ◽  
Laminar Flows ◽  
Operating Conditions ◽  
Static Mixers ◽  
Flow Through ◽  
Dispersive Mixing ◽  
Lagrangian Particle Method

Abstract This paper characterizes the mixing behavior of laminar flows within a circular pipe equipped with plain woven meshes or screens, acting as static mixers. In this quest, their performance was numerically investigated using the Lagrangian particle method in a commercial CFD solver, whereby the effect of changing the screen geometry, number of screens, inter-screen spacing, and operating conditions were considered. Mixing was addressed from a distributive and dispersive perspectives using both qualitative and quantitative descriptions. The distributive mixing indicated that a central injection of a single fluid should be coupled with a short inter-screen spacing to better spread the particles and enhance mixing as opposed to a larger inter-screen spacing. On the contrary, the mixing of two immiscible fluids of similar properties reveal that a large inter-screen spacing is recommended. From a dispersive mixing perspective, extensional efficiency contours revealed that the fluid would undergo all three modes of flow behavior, each of which dominating a certain region depending on the location with respect to the screen. Finally, it was interesting to find that a coarser screen geometry consistently outperformed finer screens in spreading and mixing the particles.

scholarly journals CFD analysis of the ventilation heating system

2019 ◽  
Vol 20 (7) ◽  
pp. 708
Author(s):  
Miroslav Rimár ◽  
Andrii Kulikov ◽  
Marcel Fedak ◽  
Milan Abraham
Keyword(s):  
Heat Balance ◽  
Cfd Simulation ◽  
Heating System ◽  
Cfd Analysis ◽  
Ansys Fluent ◽  
Closed Area ◽  
Building Ventilation ◽  
Passive Houses ◽  
Air Circulation ◽  
The Heat Balance

Air conditioning is a significant part of the contemporary life. A lot of the medical papers confirmed the influence of the thermal comfort to the operability. The aim of the article is to understand the system of the building ventilation with the HRV unit. For this purpose, the CFD simulation model was elaborated. The ANSYS Fluent allows to calculate the heat balance of the room with secondary thermal gains like computers, monitors and humans. The results of the simulation approved that in the modern thermal passive houses heat balance calculations should take into account secondary thermal gains from the installed equipment. Also the air circulation in the closed area and the influence of the different barriers installed in the laboratory were investigated.

CFD Simulation of Fin-and-Tube Heat Exchanger with Louvered Fin Configuration: Technical Note

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
M. Sabari ◽  
D. Channankiah ◽  
D. Shivalingappa
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Cfd Simulation ◽  
Calculated Data ◽  
Technical Note ◽  
Operating Conditions ◽  
Tube Heat Exchanger ◽  
Louvered Fin ◽  
Almost All

Heat exchanger plays a major role in almost all mechanical industries. Enhancement of heat transfer surface plays major role in numerous applications such as in heat exchangers, refrigeration and air conditioning systems etc. This paper examines the fluid flow and heat exchange on the air side of a multi-row fin-and-tube heat exchanger. A brief comparison is given between fin-and-tube heat exchanger attributes with louvered fins in a wider range of operating conditions defined by inlet air velocities. The brief representation on the calculated data for the louvered heat exchanger shows better heat transfer characteristics with a slightly higher pressure drop. The CFD procedure is validated by comparing the numerical simulation results with different inlet air velocities. Best combination of higher heat transfer and minimum pressure drop are occurred in inlet air velocity of 2.5 m/s.

Heat in Computers: Applied Heat Transfer in Information Technology

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Wataru Nakayama
Keyword(s):  
Heat Transfer ◽  
Integrated Circuits ◽  
Printed Circuit Board ◽  
Cfd Simulation ◽  
Coolant Flow ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Circuit Board ◽  
Evolutionary Trend ◽  
Simulation Code

Since the advent of modern electronics technology, heat transfer science and engineering has served in the development of computer technology. The computer as an object of heat transfer research has a unique aspect; it undergoes morphological transitions and diversifications in step with the progress of microelectronics technology. Evolution of computer's hardware manifests itself in increasing packing density of electronic circuits, modularization of circuit assemblies, and increasing hierarchical levels of system internal structures. These features are produced by the confluence of various factors; the primary factors are the pursuit of ever higher processing performance, less spatial occupancy, and higher energy utilization efficiency. The cost constraint on manufacturing also plays a crucial role in the evolution of computer's hardware. Besides, the drive to make computers ubiquitous parts of our society generates diverse computational devices. Concomitant developments in heat generation density and heat transfer paths pose fresh challenges to thermal management. In an introductory part of the paper, I recollect our experiences in the mainframe computers of the 1980s, where the system's morphological transition allowed the adoption of water cooling. Then, generic interpretations of the hardware evolution are attempted, which include recapturing the past experience. Projection of the evolutionary trend points to shrinking space for coolant flow, the process commonly in progress in all classes of computers today. The demand for compact packaging will rise to an extreme level in supercomputers, and present the need to refocus our research on microchannel cooling. Increasing complexity of coolant flow paths in small equipment poses a challenge to a user of computational fluid dynamics (CFD) simulation code. In highly integrated circuits the paths of electric current and heat become coupled, and coupled paths make the electrical/thermal codesign an extremely challenging task. These issues are illustrated using the examples of a consumer product, a printed circuit board (PCB), and a many-core processor chip.

scholarly journals Thermal Performance of Heat Exchanger Using Zeolite/vapour Adsorption

2021 ◽  
Vol 333 ◽  
pp. 03006
Author(s):  
Soichiro Ohno ◽  
Shuji Hironaka ◽  
Jun Fukai
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Balance ◽  
Flow Direction ◽  
Packed Bed ◽  
Maximum Temperature ◽  
Sensible Heat ◽  
Humid Air ◽  
Adsorption Heat Pump ◽  
The Heat Balance

About 60% of the energy input in the chemical industry is discarded from the plant. Energy saving can be achieved in the entire plant by recovering these waste heats and reusing them as power and heat sources in the power plant. An adsorption heat pump has been developed for the purpose of regeneration of such unused energy. In this study, saturated humid air was supplied to a device packed with 13X zeolite particles of 4 mm in diameter. The time variation of temperature in the apparatus was measured experimentally. Then, the maximum temperature was estimated from the relationship between heat balance and adsorption equilibrium. The trend of the maximum temperature calculated from the heat balance is consistent with experiment. Further, it was found from the result of the heat balance equation that the sensible heat of the humid air supplied and the heat of adsorption of the zeolite are mainly distributed to the sensible heat of the zeolite. In the future, it is important to make effective use of the sensible heat of this zeolite. In order to extract more thermal energy from the device, it is necessary to improve the heat transfer between the packed bed and medium. A double pipe heat exchanger having a zeolite packed bed on the annular side was proposed as an apparatus. Flow direction of the humid air supplied to device was changed in two different ways. The one of them is supplying humid air radial flowly to the device and another is supplying the air in parallel flow. The influence of flow direction on heat transfer between packed bed and medium is studied with numerical simulation.

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