Investigation on the impact of the environment wind velocity on the indirect air-cooling tower performance

2013 ◽  
Author(s):  
Yongbo Qin ◽  
Hongfang Gu ◽  
Haijun Wang ◽  
Guoyong Chen
Keyword(s):  
Wind Velocity ◽  
Cooling Tower ◽  
Air Cooling ◽  
The Impact

The Rod Force Law Analysis of 600MW Air Cooling Tower

2014 ◽  
Vol 945-949 ◽  
pp. 1135-1138
Author(s):  
Tao Liang ◽  
Chun Ling Meng ◽  
Yang Li ◽  
Xiu Hua Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Axial Force ◽  
Optimization Design ◽  
Cooling Tower ◽  
Air Cooling ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Cost

The finite element analysis of large air cooling tower was carried out using ABAQUS. On the basis of strength above,8 types of the axial force are analyzed and summarized, find valuable rules, and put forward the further optimization design. So that it can satisfy the strength and stability of air cooling tower, the structure is more reasonable, reduce weight, reduce the cost.

Field experience of UHPFRC durability in an air cooling tower

2010 ◽  
pp. 727-734
Author(s):  
F Toutlemonde ◽  
V Bouteiller ◽  
A Deman ◽  
G Platret ◽  
A Pavoine ◽  
...  
Keyword(s):  
Field Experience ◽  
Cooling Tower ◽  
Air Cooling

scholarly journals On the influence of basic thermodynamics on thermal cracking resistance of asphalt mixtures in cooling tests

2018 ◽  
Vol 3 ◽  
pp. 1-7
Author(s):  
Daniel Steiner ◽  
Bernhard Hofko
Keyword(s):  
Tensile Strength ◽  
Cooling Rate ◽  
Thermal Cracking ◽  
Radiation Condition ◽  
Asphalt Mixtures ◽  
Air Cooling ◽  
Laboratory Assessment ◽  
Cracking Resistance ◽  
Viscoelastic Parameters ◽  
The Impact

The cooling test or Thermal Stress Restrained Specimen Test (TSRST) simulates fully restrained pavements, as they occur in field for laboratory assessment of the thermal cracking resistance of asphalt mixtures. In the TSRST, cryogenic stress builds up due to cooling and prevented shrinkage until the tensile strength of the specimen is exceeded and the specimen fails by cracking. By carrying out TSRST various viscoelastic parameters, e.g. relaxation, evolution of tensile stresses, and tensile strength can be analyzed. Thus, a comprehensive view on the low temperature performance is possible. Standard TSRST is controlled by setting the cooling rate of the air within the chamber at a fixed value, e.g. -10°C/h. In thermodynamics, the actual cooling rate of objects is not only influenced by the cooling but also by external conditions like humidity, air velocity, radiation condition, etc. A current study investigates the impact of additional cooling parameters rather than just the air cooling rate. Two test machines of the same manufacturer that differ in the year of production and the setup of the climate chamber are compared. An initial wide scatter of test results from the two devices could be explained by taking thermodynamics into account and the reproducibility could be significantly enhanced.

scholarly journals Attempt to quantify the impact of seasonal air density variation on operating tip-speed ratio of small wind turbines

2021 ◽  
Vol 2090 (1) ◽  
pp. 012144
Author(s):  
Hiroki Suzuki ◽  
Yutaka Hasegawa ◽  
O.D. Afolabi Oluwasola ◽  
Shinsuke Mochizuki
Keyword(s):  
Wind Turbine ◽  
Wind Velocity ◽  
Governing Equation ◽  
Rotational Speed ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
Air Density ◽  
Small Wind Turbines ◽  
The Impact ◽  
Aerodynamic Torque

Abstract This study presents the impact of seasonal variation in air density on the operating tip-speed ratio of small wind turbines. The air density, which varies depending on the temperature, atmospheric pressure, and relative humidity, has an annual amplitude of about 5% in Tokyo, Japan. This study quantified this impact using the rotational speed equation of motion in a small wind turbine informed by previous work. This governing equation has been simplified by expanding the aerodynamic torque coefficient profile for a wind turbine rotor to the tip-speed ratio. Furthermore, this governing equation is simplified by using nondimensional forms of the air density, inflow wind velocity, and rotational speed with their characteristic values. In this study, the generator’s load is set to be constant based on a previous analysis of a small wind turbine. By considering the equilibrium between the aerodynamic torque and the load torque of the governing equation at the optimum tip-speed ratio, the impact of the variation in the air density on the operating tip-speed ratio was expressed using a simple mathematical form. As shown in this derived form, the operating tip-speed ratio was found to be less sensitive to a variation in air density than that in inflow wind velocity.

Photogrammetric Investigation of the Flying Shape of Spinnakers in a Twisted Flow Wind Tunnel

2009 ◽  
Author(s):  
Kai Graf ◽  
Olaf Müller
Keyword(s):  
Image Processing ◽  
Pattern Recognition ◽  
High Resolution ◽  
Wind Tunnel ◽  
Wind Velocity ◽  
Digital Cameras ◽  
Pattern Recognition Methods ◽  
Twisted Flow ◽  
High Resolution Images ◽  
The Impact

This paper describes a method for the acquisition of the flying shape of spinnakers in a twisted flow wind tunnel. The method is based on photogrammetry. A set of digital cameras is used to obtain high resolution images of the spinnaker from different viewing angles. The images are post-processed using image-processing tools, pattern recognition methods and finally the photogrammetry algorithm. Results are shown comparing design versus flying shape of the spinnaker and the impact of wind velocity and wind twist on the flying shape. Finally some common rules for optimum spinnaker trimming are investigated and examined.

scholarly journals Intercomparison of Unmanned Aircraftborne and Mobile Mesonet Atmospheric Sensors

2016 ◽  
Vol 33 (8) ◽  
pp. 1569-1582 ◽  
Author(s):  
Adam L. Houston ◽  
Roger J. Laurence ◽  
Tevis W. Nichols ◽  
Sean Waugh ◽  
Brian Argrow ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Velocity ◽  
Vertical Velocity ◽  
Humidity Sensor ◽  
Heavy Precipitation ◽  
Unmanned Aircraft ◽  
Sensor Performance ◽  
The Tempest ◽  
Aircraft System ◽  
The Impact

AbstractResults are presented from an intercomparison of temperature, humidity, and wind velocity sensors of the Tempest unmanned aircraft system (UAS) and the National Severe Storms Laboratory (NSSL) mobile mesonet (NSSL-MM). Contemporaneous evaluation of sensor performance was facilitated by mounting the Tempest wing with attached sensors to the NSSL-MM instrument rack such that the Tempest and NSSL-MM sensors could collect observations within a nearly identical airstream. This intercomparison was complemented by wind tunnel simulations designed to evaluate the impact of the mobile mesonet vehicle on the observed wind velocity.The intercomparison revealed strong correspondence between the temperature and relative humidity (RH) data collected by the Tempest and the NSSL-MM with differences generally within sensor accuracies. Larger RH differences were noted in the presence of heavy precipitation; however, despite the exposure of the Tempest temperature and humidity sensor to the airstream, there was no evidence of wet bulbing within precipitation. Wind tunnel simulations revealed that the simulated winds at the location of the NSSL-MM wind monitor were ~4% larger than the expected winds due to the acceleration of the flow over the vehicle. Simulated vertical velocity exceeded 1 m s−1 for tunnel inlet speeds typical of a vehicle moving at highway speeds. However, the theoretical noncosine reduction in winds that should result from the impact of vertical velocity on the laterally mounted wind monitor was found to be negligible across the simulations. Comparison of the simulated and observed results indicates a close correspondence, provided the crosswind component of the flow is small.

CFD Analysis of Thermal Shadowing and Optimization of Heatsinks in 3rd Generation Open Compute Server for Single-Phase Immersion Cooling

2019 ◽  
Author(s):  
Jimil M. Shah ◽  
Ravya Dandamudi ◽  
Chinmay Bhatt ◽  
Pranavi Rachamreddy ◽  
Pratik Bansode ◽  
...  
Keyword(s):  
Thermal Management ◽  
Power Density ◽  
Heat Sink ◽  
Single Phase ◽  
Data Centers ◽  
Air Cooling ◽  
Third Generation ◽  
Dielectric Fluids ◽  
Immersion Cooling ◽  
The Impact

Abstract In today’s networking world, utilization of servers and data centers has been increasing significantly. Increasing demand of processing and storage of data causes a corresponding increase in power density of servers. The data center energy efficiency largely depends on thermal management of servers. Currently, air cooling is the most widely used thermal management technology in data centers. However, air cooling has started to reach its limits due to high-powered processors. To overcome these limitations of air cooling in data centers, liquid immersion cooling methods using different dielectric fluids can be a viable option. Thermal shadowing is an effect in which temperature of a cooling medium increases by carrying heat from one source and results in decreasing its heat carrying capacity due to reduction in the temperature difference between the maximum junction temperature of successive heat sink and incoming fluid. Thermal Shadowing is a challenge for both air and low velocity oil flow cooling. In this study, the impact of thermal shadowing in a third-generation open compute server using different dielectric fluids is compared. The heat sink is a critical part for cooling effectiveness at server level. This work also provides an efficient range of heat sinks with computational modelling of third generation open compute server. Optimization of heat sink can allow to cool high-power density servers effectively for single-phase immersion cooling applications. A parametric study is conducted, and significant savings in the volume of a heat sink have been reported.

scholarly journals The Impact of Environmental Factors on the Thermal Characteristic of a Lithium–ion Battery

Batteries ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Gerd Liebig ◽  
Ulf Kirstein ◽  
Stefan Geißendörfer ◽  
Frank Schuldt ◽  
Carsten Agert
Keyword(s):  
Lithium Ion Battery ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Heat Removal ◽  
Lithium Ion ◽  
Air Cooling ◽  
Heat Rejection ◽  
Study Results ◽  
Electrochemical Model ◽  
The Impact

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 Ah prismatic lithium–ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries’ interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations; (2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell; (3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries’ lifespan.

Optimal Vacuum Calculation and Analysis of Composite-Cycle Air-Cooling System

2013 ◽  
Vol 718-720 ◽  
pp. 1687-1690 ◽  
Author(s):  
Sheng Long Wang ◽  
Wen Hao Li ◽  
Yin Hai Ge
Keyword(s):  
Cooling System ◽  
Calculation Model ◽  
Climatic Conditions ◽  
System Structure ◽  
Air Cooling ◽  
Air Cooling System ◽  
Working Principle ◽  
Annual Earnings ◽  
Correct Understanding ◽  
The Impact

In this paper, the research object is composite-cycle air-cooling system. First,gave a brief introduction of the system structure and the working principle in power plant. Then the optimal vacuum calculation model was established with the analysis of performance indicators and the amount of equipment production, consumption power of system. Analyze the impact of the ambient temperature to system optimal vacuum in variable conditions. Lastly, combining the climatic conditions of example, which can be drawn is that when the annual best vacuum is 4.8kPa, the running annual earnings is the highest. This article provides guiding significance for correct understanding and engineering applications of composite-cycle air-cooling systems, also further confirm the feasibility of composite-cycle air-cooling system.

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