scholarly journals Application Study on a New Hybrid Canning Structure of After-Treatment System for Diesel Engine

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 734 ◽  
Author(s):  
Zhao ◽  
Lou ◽  
Zhang ◽  
Lu ◽  
Liu
Keyword(s):  
Conversion Efficiency ◽  
Cfd Simulation ◽  
Catalytic Reduction ◽  
Hybrid Structure ◽  
Structure Design ◽  
Treatment System ◽  
Actual Performance ◽  
Performance Requirements ◽  
Crystallization Risk ◽  
Packaging Structure

Based on the airflow rotation concept, a new packaging structure was designed to meet the performance requirements of China-VI stage emission regulations. The new structure is a hybrid structure of spiral space with small blades and conical plates. The Computational Fluid Dynamics (CFD) simulation was used to analyze the velocity uniformity and ammonia uniformity of the flow field, and the results showed that velocity uniformity and ammonia uniformity were higher than 0.95, and the possibility of crystallization risk was very low. The actual performance of the new structural prototype was verified by means of engine bench testing. The test results were excellent and the conversion efficiency reached 0.96. The new selective catalytic reduction (SCR) urea mixed structure design greatly improved the conversion efficiency of the after-treatment system and has excellent anti-crystallization performance.

An anti-crystallization design of selective catalytic reduction nozzle holder

2021 ◽  
pp. 095440702097084
Author(s):  
Dewen Liu ◽  
Kai Lu ◽  
Shusen Liu ◽  
Yan Wu ◽  
Shuzhan Bai
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Injection System ◽  
Test Results ◽  
Verification Methods ◽  
Crystallization Risk ◽  
Protective Cover ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Good Agreement

From the aspect of reducing the risk of crystallization on nozzle surface, a new design of nozzle protective cover was to solve the problem in selective catalytic reduction (SCR) urea injection system. The simulation calculation and experimental verification methods were used to compare different schemes. The results show that reducing the height of nozzle holder can reduce the vortex currents near nozzle surface and effectively reduce the risk of crystallization on the nozzle surface. It is proposed to install a protective cover in the nozzle holder under the scheme of reducing the height of nozzle holder, which can further eliminate the vortex. Simulation and test results demonstrate good agreement under the rated running condition. The scheme of adding a protective cover in the nozzle holder shows the least crystallization risk by computational fluid dynamics (CFD) method. The crystallization cycle test shows that, after the height of nozzle holder is reduced, the risk of crystallization on the nozzle surface is reduced correspondingly. The addition of a protective cover in the nozzle holder solves the problem of crystallization on the nozzle surface, which provides a new method for anti-crystallization design.

scholarly journals The influence of the injection frequency on the urea selective catalytic reduction systems performance

2017 ◽  
Vol 170 (3) ◽  
pp. 73-77
Author(s):  
Rafał ROGÓŻ ◽  
Piotr JAWORSKI ◽  
Łukasz KAPUSTA ◽  
Andrzej TEODORCZYK
Keyword(s):  
Diesel Engine ◽  
System Performance ◽  
Catalytic Reduction ◽  
Film Formation ◽  
Flow Conditions ◽  
Wall Film ◽  
Injection Frequency ◽  
Crystallization Risk ◽  
Film Characteristics ◽  
Operating Points

This study presents the influence of the UWS injection frequency on a close coupled SCR systems performance. The investigation was performed with the CFD tool AVL Fire. In the paper the analysis of four different UWS injection frequencies in the three different operating points of diesel engine was shown. The assessments of the system performance was referred to the ammonia distribution at catalyst intake and wall film formation inside the investigated geometry, as these are considered as crucial in such a configuration. The results showed that injection frequency affects both factors on different level depending from the flow conditions. In addition, the wall film crystallization risk was discussed basing on the obtained wall film characteristics.

Interesting Packaging Structure Design of Children’s Biscuits

2014 ◽  
Vol 989-994 ◽  
pp. 3262-3265
Author(s):  
Yu Ming Qi ◽  
Wen Hua Gao
Keyword(s):  
Structure Design ◽  
Jigsaw Puzzle ◽  
Packaging Design ◽  
Children's Attention ◽  
Packaging Structure

Biscuit, as a common snack, in order to attract the children’s attention, besides its taste and shape, packaging design is equally important. The beautifully decorated surface of the box can be divided into a number of blocks (4 or 9) by setting the punch lines. After the biscuits are eaten up, tear the box along the punch lines, then it becomes a simple jigsaw puzzle. Inside the box except the biscuits bag, a cute clamp like scissors added. So the children can gripping biscuits by the clamp rather than by hand directly.

Structure Design for Heat Sink Based on Thermal Analysis

2011 ◽  
Vol 80-81 ◽  
pp. 767-773
Author(s):  
Hai Gang Sun ◽  
Yong Zhou
Keyword(s):  
Thermal Analysis ◽  
Thermal Performance ◽  
Heat Sink ◽  
Cfd Simulation ◽  
Thermal Control ◽  
Structure Design ◽  
Thermal Design ◽  
Structure Parameters ◽  
Igbt Module ◽  
Key Factor

Thermal design and the working temperature control have been a key factor in the design of electronic devices and system. In this paper, a sort of heat sink collocated with high-power IGBT module, which is commonly used in car-carrying motor control system, is designed based on thermal analysis by means of CFD simulation and computer-aided analyzing, also the influence relations of structure parameters with thermal performance are studied. With thermal control as the overall design objective, structure parameters of heat sink are determined according to the obtained relations. Further, thermal performance of the designed heat sink is simulated and analyzed in CFD software to examine the validity of the design result. In this way, a method of thermal analyzing and structure parameter design for heat sink, which is proved as an efficacious approach, is introduced and can be used to thermal design and analysis for similar products.

scholarly journals High-Efficient Micro Reacting Pipe with 3D Internal Structure: Design, Flow Simulation, and Metal Additive Manufacturing

2020 ◽  
Vol 10 (11) ◽  
pp. 3779
Author(s):  
Xiaomin Chen ◽  
Di Wang ◽  
Jingming Mai ◽  
Xiaojun Chen ◽  
Wenhao Dou
Keyword(s):  
Fluid Flow ◽  
Additive Manufacturing ◽  
Internal Structure ◽  
Cfd Simulation ◽  
Structure Design ◽  
Design Flow ◽  
Mixing Efficiency ◽  
Metal Additive Manufacturing ◽  
High Efficient ◽  
Metal Additive

The micro reacting pipe with 3D internal structure, which is a micromixer with the shape of the pipe, has shown great advantages regarding mass transfer and heat transfer. Since the fluid flow is mostly laminar at the micro-scale, which is unfavorable to the diffusion of reactants, it is important to understand the influence of the geometry of the microchannel on the fluid flow for improving the diffusion of the reactants and mixing efficiency. On the other hand, it is a convenient method to manufacture a micro reacting pipe in one piece through metal additive manufacturing without many post-processing processes. In this paper, a basis for the design of a micromixer model was provided by combining the metal additive manufacturing process constraints with computational fluid dynamics (CFD) simulation. The effects of microchannel structures on fluid flow and mixing efficiency were studied by CFD simulation whose results showed that the internal micro-structure had a significantly positive effect on the mixing efficiency. Based on the simulation results, the splitting-collision mechanism was discussed, and several design rules were obtained. Two different materials were selected for manufacturing with the laser powder bed fusion (L-PBF) technology. After applying pressure tests to evaluate the quality of the formed parts and comparing the corrosion-resistance of the two materials, one material was picked out for the industrial application. Additionally, the chemical experiment was conducted to evaluate the accuracy of the simulation. The experimental results showed that the mixing efficiency of the micro reacting pipe increased by 56.6%, and the optimal determining size of the micro reacting pipe was 0.2 mm. The study can be widely used in the design and manufacture of a micromixer, which can improve efficiency and reacting stability in this field.

The Theory of Green Packaging Design and its Application

2014 ◽  
Vol 635-637 ◽  
pp. 248-252 ◽  
Author(s):  
Fen Fen Zhou
Keyword(s):  
Structure Design ◽  
Living Environment ◽  
Packaging Materials ◽  
Human Society ◽  
Design Work ◽  
Packaging Design ◽  
Green Packaging ◽  
The Times ◽  
The One ◽  
Packaging Structure

With the development of science and technology and the progress of human society,We gradually know that survival environment is worsening,the further development of the economy has been restricted.These problems directly affect the reproduction of human civilization,So our country put forward the strategy of sustainable development.The concept of green packaging design is adapted to the demand of the times,in order to explore the application of the green idea in the packaging design.Green packaging design needs to consider packaging materials,this will affect the packaging cost.The 60% ~ 80% of the packaging cost have been confirmed in the product design stage.Green packaging structure design should be considered,the structure of reasonable design of packaging, not only can reduce cost, but also reduce the adverse impact on the environment.When we need to use the least amount of packaging materials,a sphere is the best choice.The height of the cylinder is equal to the radius of 2 times through calculation,Its surface area is smallest.Green packaging, therefore, on the one hand, can avoid the waste of resources,let our design work can be harmonious with our living environment.

Tolerance Modeling and Optimization of XY-Table for LED Die Bonder Based on Multi-Body Systems

2011 ◽  
Vol 201-203 ◽  
pp. 2922-2926
Author(s):  
Mei Fa Huang ◽  
Jiang Tai Huang ◽  
Xiong Cheng ◽  
Jing Zhang ◽  
Hui Jing
Keyword(s):  
Optimization Model ◽  
High Speed ◽  
High Performance ◽  
Geometric Error ◽  
Structure Design ◽  
Manufacturing Costs ◽  
Tolerance Optimization ◽  
Performance Requirements ◽  
Multi Body ◽  
Geometry Error

High performance XY-table is commonly used in packaging equipments which needs rational tolerance to ensure its high performance requirements and low manufacturing costs. The related studies mainly focus on high speed motion control algorithms and high precision structure design. The proper tolerance is essential in the development process of new products. In this paper, a new method for tolerance optimization based on Multi-body systems is presented. The volumetric error model for XY-table is established based on Multi-body systems. And then, by identifying the basic geometric error components, the relationships between the final output precision of the XY-table and the geometry error sources are established. The tolerance optimization model of XY-table using the above relationships is presented. In this model, objective function is the total manufacturing costs and the constraints are the above relationships. By solving the optimization model, the optimal tolerances are obtained. Finally, a tolerance design example of LED die bonder is given to illustrate the proposed method.

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