scholarly journals Numerical Simulation of Passive Cooling Beam and Its Optimization to Increase the Cooling Power

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1478
Author(s):  
Katarína Kaduchová ◽  
Richard Lenhard
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Mathematical Model ◽  
Significant Influence ◽  
Cooling Capacity ◽  
Passive Cooling ◽  
Cooling Power ◽  
Geometrical Parameters ◽  
Confined Space ◽  
Cooling Performance

This article is focused on the research of passive cooling beams and increasing their cooling capacity. A passive cooling beam with four tubes was chosen as a model. A mathematical model was built using the corresponding criterion equations to capture the behavior of a passive cooling beam. This mathematical model can be used to optimize geometrical parameters (the distance between the ribs, rib height and thickness, and diameter and number of tubes), by changing these geometric parameters we can increase the cooling performance. The work includes a mathematical model for calculating the boundary layer, which has a significant influence on the cooling performance. The results obtained from the created mathematical model show that the model works correctly and can be used to optimize the cooling performance of passive cooling beams. To better understand the behavior of a passive cooling beam in a confined space, the entire device was numerically simulated, as was the flow in the intercostal space.

Numerical Simulation of Indirectly Heated Hot Water Heater

2014 ◽  
Vol 875-877 ◽  
pp. 1693-1697 ◽  
Author(s):  
Richard Lenhard ◽  
Katarína Kaduchová ◽  
Jozef Jandačka
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Volume ◽  
Computational Methods ◽  
Finite Volume Methods ◽  
Hot Water ◽  
Geometrical Parameters ◽  
Water Heater ◽  
Cfd Simulations ◽  
Cfd Method

This paper describes a mathematical model of heating hot water for indirectly heated hot water heater. Using the established mathematical model was carried out simulation of the device to change its geometrical parameters. Based on the results of simulations was carried out optimization of indirectly heated hot water heater for hot water. Subsequently been made CFD simulations of the device, and those were compared with a mathematical model to verify the accuracy of the proposed mathematical model of heating hot water for indirectly heated hot water heater. Computational methods based on finite volume methods (CFD method) have proved very useful in optimizing indirectly heated hot water heater.

scholarly journals Enhanced Thermoelectric Cooling through Introduction of Material Anisotropy in Transverse Thermoelectric Composites

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2049
Author(s):  
Bosen Qian ◽  
Fei Ren ◽  
Yao Zhao ◽  
Fan Wu ◽  
Tiantian Wang
Keyword(s):  
Mathematical Model ◽  
Single Crystal ◽  
Material Properties ◽  
Cooling Capacity ◽  
Thermoelectric Performance ◽  
Cooling Power ◽  
Material Anisotropy ◽  
Element Analysis ◽  
The Mathematical Model ◽  
Component Phase

Transverse thermoelectric materials can achieve appreciable cooling power with minimal space requirement. Among all types of material candidates for transverse thermoelectric applications, composite materials have the best cooling performance. In this study, anisotropic material properties were applied to the component phase of transverse thermoelectric composites. A mathematical model was established for predicting the performance of fibrous transverse thermoelectric composites with anisotropic components. The mathematical model was then validated by finite element analysis. The thermoelectric performance of three types of composites are presented, each with the same set of component materials. For each type of component, both anisotropic single-crystal and isotropic polycrystal material properties were applied. The results showed that the cooling capacity of the system was improved by introducing material anisotropy in the component phase of composite. The results also indicated that the orientation of the anisotropic component’s property axis, the anisotropic characteristic of a material, will significantly influence the thermoelectric performance of the composite. For a composite material consisting of Copper fiber and Bi2Te3 matrix, the maximum cooling capacity can vary as much as 50% at 300 K depending on the property axis alignment of Bi2Te3 in the composite. The composite with Copper and anisotropic SnSe single crystal had a 51% improvement in the maximum cooling capacity compared to the composite made of Copper and isotropic SnSe polycrystals.

Performance Analysis and Optimization of High Capacity Pulse Tube Refrigerator

2010 ◽  
Author(s):  
Amir R. Ghahremani ◽  
F. Roshanghalb ◽  
R. Jahanbakhshi ◽  
M. H. Saidi ◽  
S. Kazemzadeh Hannani
Keyword(s):  
High Capacity ◽  
Cooling Capacity ◽  
Cooling Power ◽  
Operating Parameters ◽  
Geometrical Parameters ◽  
Average Charge ◽  
Pulse Tube ◽  
Pulse Tube Refrigerator ◽  
Aspect Ratios ◽  
Pulse Tube Refrigerators

High capacity pulse tube refrigerator (HCPTR) is a new generation of cryocoolers tailored to provide more than 250 W of cooling power at cryogenic temperatures. The most important characteristics of HCPTR when compared with other types of pulse tube refrigerators are a powerful pressure wave generator, and an accurate design. In this paper the influence of geometrical and operating parameters on the performance of a double inlet pulse tube refrigerator (DIPTR) is studied. The DIPTR is modeled applying the nodal analysis technique, using mass, momentum and energy conservation equations. The model is able to compute instantaneous flow field throughout the system and calculate cooling capacity and COP. The model is validated with the existing experimental data. To perform the optimized mode of operation, the influence of both geometrical and operating parameters on cooling capacity and COP is investigated. The key geometrical parameters considered in this paper are aspect ratios of regenerator and tube section, length ratio of regenerator and tube, and type of screen mesh. The main operating parameters considered are average charge pressure, and position of opening of orifice and bypass. As a result of this optimization a new configuration of HCPTR is proposed. This configuration provides 300 W at 80 K cold end temperature with a frequency of 50 Hz and COP of 0.054.

scholarly journals Numerical Analysis on the Performance of a Radiant Cooling Panel with Serpentine-Based Design

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4744
Author(s):  
Mohammad Hakim Mohd Radzai ◽  
Chong Tak Yaw ◽  
Chin Wai Lim ◽  
Siaw Paw Koh ◽  
Nur Amirani Ahmad
Keyword(s):  
Pressure Drop ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Dew Point ◽  
Cooling Power ◽  
Full Potential ◽  
Ansys Fluent ◽  
Cooling Performance ◽  
Flow Configuration ◽  
Radiant Cooling

Radiant cooling systems (RCS) are gaining acceptance as a heating, ventilation, and air conditioning (HVAC) solution for achieving adequate thermal comfort and maintaining acceptable indoor air quality inside buildings. RCS are well known for their energy-saving potential; however, serious condensation problem hinders the growth of this technology. In order to prevent the risk of condensation, the supply water temperature is kept higher than the dew point temperature of the air inside the room. The full potential of the cooling power of a radiant cooling panel is limited. Therefore, this article is on maximizing the cooling capacity of a radiant cooling panel, in terms of flow configuration. Radiant cooling panels (RCP) with different chilled water pipe configurations are designed and compared, side by side with the conventional serpentine flow configuration. The cooling performance of the radiant cooling panels is evaluated by using computational fluid dynamics (CFD) with Ansys Fluent software (Ansys 2020 R2, PA, USA). Under similar flow and operating conditions, the common serpentine flow configuration exhibits the least effective cooling performance, with the highest pressure drop across the pipe. It is concluded that the proposed designs have the potential of improving the overall efficiency of RCP in terms of temperature distribution, cooling capacity, and pressure drop.

MODELING OF THE DYNAMIC PROCESS RELEASE OF STUCK DRILLING TOOLS BY HYDRO-PULSE METHOD

2019 ◽  
pp. 94-103
Author(s):  
K. H. Levchyk ◽  
M. V. Shcherbyna
Keyword(s):  
Mathematical Model ◽  
Dynamic Process ◽  
Drilling Fluid ◽  
Pulse Method ◽  
Geometrical Parameters ◽  
Technical Solution ◽  
Rock Layer ◽  
Drilling Tool ◽  
Drilling Tools ◽  
Drill Pipes

A technical solution is proposed for the elimination the grabbing of drilling tool, based on the use of energy due to the circulation of the drilling fluid. The expediency eliminating the grabbing drilling tool using the hydro-impulse method is substantiated. A method of drawing up a mathematical model for the dynamic process of a grabbing string of drill pipes in the case of perturbation of hydro-impulse oscillations in the area of the productive rock layer is developed. The law of longitudinal displacements arising in the trapped string is obtained, which allows choosing the optimal geometrical parameters of the passage channels and the frequency rotational of shutter for these channels. Recommendations for using this method for practical use have been systematized.

A simplified method of temperature control maximizing productivity of the batch reactor; The effect of inertia of the cooling system

1982 ◽  
Vol 47 (2) ◽  
pp. 454-464 ◽  
Author(s):  
František Jiráček ◽  
Josef Horák
Keyword(s):  
Mathematical Model ◽  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Cooling Capacity ◽  
Variable Activity ◽  
Simplified Method ◽  
Opening And Closing ◽  
Time Of Operation

The effect has been studied of the inertia of the cooling system on the reliability of control of the temperature of the reaction mixture. The study has been made using a mathematical model of the batch reactor with an exothermic reaction. The temperature has been controlled by a two-level controller opening and closing the flow of the coolant. The aim of the control has been to maintain a constant value of the degree of utilization of the cooling capacity of the reactor. The instantaneous value of the degree of utilization has been assessed from the ratio of times for which the cooling system is idle to the time of operation. The reliability of control has been studied for variable activity of the catalyst.

scholarly journals Computer Modeling of Aerosol Emissions Spread in the Atmosphere

2019 ◽  
Vol 97 ◽  
pp. 05023 ◽  
Author(s):  
Daler Sharipov ◽  
Sharofiddin Aynakulov ◽  
Otabek Khafizov
Keyword(s):  
Boundary Layer ◽  
Mathematical Model ◽  
Atmospheric Boundary Layer ◽  
Computer Modeling ◽  
Numerical Experiments ◽  
Climatic Factors ◽  
Numerical Algorithms ◽  
Aerosol Emissions ◽  
The Given ◽  
And Diffusion

The paper deals with the development of mathematical model and numerical algorithms for solving the problem of transfer and diffusion of aerosol emissions in the atmospheric boundary layer. The model takes into account several significant parameters such as terrain relief, characteristics of underlying surface and weather-climatic factors. A series of numerical experiments were conducted based on the given model. The obtained results presented here show how these factors affect aerosol emissions spread in the atmosphere.

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