scholarly journals Study on Transport Packages Used for Food Freshness Preservation based on ANSYS Thermal Analysis

2016 ◽  
Vol 20 (2) ◽  
pp. 95-110
Author(s):  
Ying Yu
Keyword(s):  
Heat Transfer ◽  
Minimum Energy ◽  
Diesel Oil ◽  
Heat Transfer Process ◽  
Cold Chain ◽  
Cost Of Transport ◽  
Minimum Energy Consumption ◽  
Heat Transfer Theory ◽  
Seafood Products ◽  
The Cost

Abstract In recent years, as the Chinese consumption level increases, the consumption quantity of high-value fruits, vegetables and seafood products have been increasing year by year. As a consequence, the traffic volume of refrigerated products also increases yearly and the popularization degree of the cold-chain transportation enhances. A low-temperature environment should be guaranteed during transportation, thus there is about 40% of diesel oil should be consumed by the refrigerating system and the cold-chain transportation becomes very costly. This study aimed to explore a method that could reduce the cost of transport packages of refrigerated products. On the basis of the heat transfer theory and the fluid mechanics theory, the heat exchange through corrugated cases during the operation of refrigerating system was analyzed, the heat transfer process of corrugated cases and refrigerator van was theoretically analyzed and the heat balance equation of corrugated cases was constructed. Besides, this study simulated the temperature field of the corrugated box during transportation. The temperature of the goods was changed through different cooling temperature to calculate the minimum energy consumption, so as to achieve the best refrigeration transport packaging program.

scholarly journals Study on transport packages used for food freshness preservation based on thermal analysis

2016 ◽  
Vol 37 (4) ◽  
pp. 121-135
Author(s):  
Ying Yu
Keyword(s):  
Heat Transfer ◽  
Diesel Oil ◽  
Heat Transfer Process ◽  
Cold Chain ◽  
Cost Of Transport ◽  
Heat Transfer Theory ◽  
Seafood Products ◽  
Food Freshness ◽  
The Cost ◽  
The Heat Balance

AbstractIn recent time, as the Chinese consumption level increases, the consumption quantity of high-value fruits, vegetables and seafood products have been increasing year by year. As a consequence, the traffic volume of refrigerated products also increases yearly and the popularization degree of the cold-chain transportation enhances. A low-temperature environment should be guaranteed during transportation, thus there is about 40% of diesel oil should be consumed by the refrigerating system and the cold-chain transportation becomes very costly. This study aimed to explore methods that could reduce the cost of transport packages of refrigerated products. On the basis of the heat transfer theory and the fluid mechanics theory, the heat exchanging process of corrugated cases during the operation of refrigerating system was analyzed, the heat transfer process of corrugated cases and refrigerator van was theoretically analyzed and the heat balance equation of corrugated cases was constructed.

From Construction to Operation: Achieving Indoor Thermal Comfort via Altering External Walls Specifications in Egypt

2013 ◽  
Vol 689 ◽  
pp. 250-253 ◽  
Author(s):  
Mohamed M. Mahdy ◽  
Marialena Nikolopoulou
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Minimum Energy ◽  
Residential Energy ◽  
Indoor Thermal Comfort ◽  
Minimum Energy Consumption ◽  
Different Types ◽  
Running Cost ◽  
The Cost

The objective of this research is to study the effect of using different material specifications for the external walls on the cost of the energy consumption for achieving internal thermal comfort. We refer to this as operation running cost, which in turn is compared to initial construction cost for each type of the used external walls. In order to achieve this objective, dynamic thermal simulation were carried out for four different types of external walls – commonly used in Egypt – in two different sets of cooling: natural ventilation and mechanical means. Experiments recommend that using the Egyptian Residential Energy Code (EREC) to achieve inner thermal comfort with the minimum energy consumption (consequently the minimum CO2 emissions) and the minimum running cost as well.

Shape and Size Optimization Design of Finned Brass Tube on the Central Air Conditioning

2012 ◽  
Vol 588-589 ◽  
pp. 1854-1857
Author(s):  
Shuang Chen ◽  
Bing Yan Zhang ◽  
Jian Hua Zhong
Keyword(s):  
Heat Transfer ◽  
Transfer Process ◽  
Optimization Design ◽  
Heat Transfer Process ◽  
Finned Tube ◽  
Structure Parameters ◽  
Finite Element Program ◽  
Fin Efficiency ◽  
Heat Transfer Theory ◽  
Element Program

Finned tube heat transfer process was analyzed in this thesis, the optimal mathematical model of the fin efficiency and fin volume which was acted as the objective function is established based on the model of heat transfer theory. The heat exchanger numerical simulation of finned tube is taken by the ANSYS finite element program in heat transfer process, and the finned tube structure parameters ( fin spacing , fin thickness , fin height) were analyzed , the optimum structure parameters of a set of finned tube were obtained at the same time. These studies will have some guidance on the application of finned tubes.

Multivariable Extremum Seeking for Joint-Space Trajectory Optimization of a High-Degrees-of-Freedom Robot

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Mostafa Bagheri ◽  
Miroslav Krstić ◽  
Peiman Naseradinmousavi
Keyword(s):  
Trajectory Optimization ◽  
Degrees Of Freedom ◽  
Research Effort ◽  
Minimum Energy ◽  
Joint Space ◽  
Design Sensitivity ◽  
Extremum Seeking ◽  
Minimum Energy Consumption ◽  
Gradient Based ◽  
The Cost

In this paper, a novel analytical coupled trajectory optimization of a seven degrees-of-freedom (7DOF) Baxter manipulator utilizing extremum seeking (ES) approach is presented. The robotic manipulators are used in network-based industrial units, and even homes, by expending a significant lumped amount of energy, and therefore, optimal trajectories need to be generated to address efficiency issues. These robots are typically operated for thousands of cycles resulting in a considerable cost of operation. First, coupled dynamic equations are derived using the Lagrangian method and experimentally validated to examine the accuracy of the model. Then, global design sensitivity analysis is performed to investigate the effects of changes of optimization variables on the cost function leading to select the most effective ones. We examine a discrete-time multivariable gradient-based ES scheme enforcing operational time and torque saturation constraints in order to minimize the lumped amount of energy consumed in a path given; therefore, time-energy optimization would not be the immediate focus of this research effort. The results are compared with those of a global heuristic genetic algorithm (GA) to discuss the locality/globality of optimal solutions. Finally, the optimal trajectory is experimentally implemented to be thoroughly compared with the inefficient one. The results reveal that the proposed scheme yields the minimum energy consumption in addition to overcoming the robot's jerky motion observed in an inefficient path.

scholarly journals OPTIMIZATION OF HEAT PROTECTION CHARACTERISTICS OF COUNTRY COTTAGE ENCLOSURES

2021 ◽  
Vol 11 (1) ◽  
pp. 39-45
Author(s):  
Yuri S. VYTCHIKOV ◽  
Mikhail E. SAPAREV ◽  
Vladislav A. GOLIKOV ◽  
Evgeniy G. SAFRONOV
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Thermal Protection ◽  
Minimum Energy ◽  
Thermal Conditions ◽  
Outer Wall ◽  
Wall Material ◽  
Transfer Resistance ◽  
Heating Systems ◽  
Minimum Energy Consumption

The article presents a method for determining the minimum permissible value of the heat transfer resistance of the outer wall, at which the minimum energy consumption is achieved during the operation of buildings with variable thermal conditions. A review of the sources devoted to this problem showed the presence of high costs of thermal energy during the heating of premises. On the basis of studies of all components of energy consumption in the operation of premises with intermitt ent heating systems, the authors of the article propose a method for determining the minimum permissible resistance to heat transfer, which provides minimum energy consumption. According to the described method, the calculation was made for external walls made of various materials. The analysis of the obtained results showed that a signifi cant infl uence on the minimum permissible value of the heat transfer resistance is exerted by a complex of thermophysical values cρλ. The presented graphical dependence R0 усл on the complex cρλ allows the designer to rationally choose a wall material that provides a minimum of energy consumption during the operation of the building. In the context of rising energy tariff s, such optimization of thermal protection characteristics is especially important for country cott ages operated in intermitt ent heating conditions.

A Comparative Study on the Fire Resistance of Ordinary Grade Structural Steels

2014 ◽  
Vol 904 ◽  
pp. 228-231
Author(s):  
In Kyu Kwon
Keyword(s):  
Heat Transfer ◽  
Fire Resistance ◽  
Fire Test ◽  
Structural Steels ◽  
Mechanical And Thermal Properties ◽  
Structural Elements ◽  
Heat Transfer Theory ◽  
Eurocode 3 ◽  
The Cost ◽  
Fire Design

Fire resistance of structural elements such as columns and beams has been evaluated by the fire test. However, needs of fire design based on analysis using a heat transfer theory and a stress analysis are increasing because the design can reduce not only the period of the fire test but the cost of it. The reliability of the analysis would be totally dependent on the mechanical, thermal databases of their structural steels. This paper evaluates the fire resistance of ordinary grade structural steels manufactured from Korea by examining the mechanical and thermal properties of SS 400, SM 400, and SM 490 at high temperature and comparing them with those defined in Eurocode 3. The results showed that the ordinary structural steel had almost the same characteristics as those in Eurocode 3.

scholarly journals Effect of Machine Entropy Production on the Optimal Performance of a Refrigerator

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 913 ◽  
Author(s):  
Michel Feidt ◽  
Monica Costea
Keyword(s):  
Heat Transfer ◽  
Entropy Production ◽  
Optimal Allocation ◽  
Minimum Energy ◽  
Transfer Entropy ◽  
Coefficient Of Performance ◽  
Environmental Constraints ◽  
Minimum Energy Consumption ◽  
Control Command ◽  
Internal Irreversibility

The need for cooling is more and more important in current applications, as environmental constraints become more and more restrictive. Therefore, the optimization of reverse cycle machines is currently required. This optimization could be split in two parts, namely, (1) the design optimization, leading to an optimal dimensioning to fulfill the specific demand (static or nominal steady state optimization); and (2) the dynamic optimization, where the demand fluctuates, and the system must be continuously adapted. Thus, the variability of the system load (with or without storage) implies its careful control-command. The topic of this paper is concerned with part (1) and proposes a novel and more complete modeling of an irreversible Carnot refrigerator that involves the coupling between sink (source) and machine through a heat transfer constraint. Moreover, it induces the choice of a reference heat transfer entropy, which is the heat transfer entropy at the source of a Carnot irreversible refrigerator. The thermodynamic optimization of the refrigerator provides new results regarding the optimal allocation of heat transfer conductances and minimum energy consumption with associated coefficient of performance (COP) when various forms of entropy production owing to internal irreversibility are considered. The reported results and their consequences represent a new fundamental step forward regarding the performance upper bound of Carnot irreversible refrigerator.

scholarly journals Evaluation of the minimum energy hypothesis and other potential optimality criteria for human running

2011 ◽  
Vol 279 (1733) ◽  
pp. 1498-1505 ◽  
Author(s):  
Ross H. Miller ◽  
Brian R. Umberger ◽  
Joseph Hamill ◽  
Graham E. Caldwell
Keyword(s):  
Muscle Activation ◽  
Minimum Energy ◽  
Muscular Activity ◽  
Optimality Criteria ◽  
Cost Of Transport ◽  
Potential Control ◽  
Gait Mechanics ◽  
The Cost ◽  
Total Muscle ◽  
Human Running

A popular hypothesis for human running is that gait mechanics and muscular activity are optimized in order to minimize the cost of transport (CoT). Humans running at any particular speed appear to naturally select a stride length that maintains a low CoT when compared with other possible stride lengths. However, it is unknown if the nervous system prioritizes the CoT itself for minimization, or if some other quantity is minimized and a low CoT is a consequential effect. To address this question, we generated predictive computer simulations of running using an anatomically inspired musculoskeletal model and compared the results with data collected from human runners. Three simulations were generated by minimizing the CoT, the total muscle activation or the total muscle stress, respectively. While all the simulations qualitatively resembled real human running, minimizing activation predicted the most realistic joint angles and timing of muscular activity. While minimizing the CoT naturally predicted the lowest CoT, minimizing activation predicted a more realistic CoT in comparison with the experimental mean. The results suggest a potential control strategy centred on muscle activation for economical running.

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