scholarly journals Experimental Investigation on Start-up and Isothermal Performance of Thermosyphon with Noncondensable Gas

2021 ◽  
Vol 245 ◽  
pp. 01056
Author(s):  
Bin Ren ◽  
Xuchen Zhu ◽  
Yannan Du ◽  
Zhe Pu ◽  
Aini He ◽  
...  
Keyword(s):  
Wall Temperature ◽  
Low Cost ◽  
Experimental Methods ◽  
Condenser Section ◽  
Noncondensable Gas ◽  
Working Temperature ◽  
Start Up ◽  
Condensation Section ◽  
Heat Transfer Capacity ◽  
Gas Ratio

Steel-water gravity heat pipe has been widely used in industry because of its low cost and wide applicable temperature range. Steel-water incompatibility can produce hydrogen as a non-condensable gas, seriously weakening the heat transfer capacity. In this paper, the start-up and isothermal performance of thermosyphon with noncondensable gas were studied by experimental methods, and the effect of gas ratio on the start-up and isothermal performance was quantitatively analysed. The results show that the larger gas ratio will increase the start-up time and the working temperature. The wall temperature of evaporation section is higher than that of adiabatic and condensation section. The distributions of wall temperature in the evaporator and adiabatic sections are uniform. The non-isothermal phenomenon only occurs in the condenser section.

scholarly journals Aiming Strategy on a Prototype-Scale Solar Receiver: Coupling of Tabu Search, Ray-Tracing and Thermal Models

2021 ◽  
Vol 13 (7) ◽  
pp. 3920
Author(s):  
Benjamin Grange ◽  
Gilles Flamant
Keyword(s):  
Tabu Search ◽  
Ray Tracing ◽  
Wall Temperature ◽  
Gradual Increase ◽  
Particle Temperature ◽  
Outlet Temperature ◽  
Operation Conditions ◽  
Start Up ◽  
Fluidized Particle ◽  
Solar Receiver

An aiming point strategy applied to a prototype-scale power tower is analyzed in this paper to define the operation conditions and to preserve the lifetime of the solar receiver developed in the framework of the Next-commercial solar power (CSP) H2020 project. This innovative solar receiver involves the fluidized particle-in-tube concept. The aiming solution is compared to the case without the aiming strategy. Due to the complex tubular geometry of the receiver, results of the Tabu search for the aiming point strategy are combined with a ray-tracing software, and these results are then coupled with a simplified thermal model of the receiver to evaluate its performance. Daily and hourly aiming strategies are compared, and different objective normalized flux distributions are applied to quantify their influence on the receiver wall temperature distribution, thermal efficiency and particle outlet temperature. A gradual increase in the solar incident power on the receiver is analyzed in order to keep a uniform outlet particle temperature during the start-up. Results show that a tradeoff must be respected between wall temperature and particle outlet temperature.

Development of a low-cost smart vehicle start up and tracking system using Android and Arduino

2020 ◽  
Vol 15 (3/4) ◽  
pp. 271
Author(s):  
Sundresan Perumal ◽  
Mujahid Tabassum ◽  
Dayang Siti Nur Amirah Bt Ab Ahmad Zulkipli
Keyword(s):  
Tracking System ◽  
Low Cost ◽  
Start Up ◽  
Smart Vehicle

High Voltage, Flexible and Low Cost All‐Solid‐State Lithium Metal Batteries with a Wide Working Temperature Range

2020 ◽  
Vol 5 (3) ◽  
pp. 1214-1219 ◽  
Author(s):  
Yuchan Zhang ◽  
Huifang Fei ◽  
Yongling An ◽  
Chuanliang Wei ◽  
Jinkui Feng
Keyword(s):  
Solid State ◽  
High Voltage ◽  
Low Cost ◽  
Lithium Metal ◽  
Temperature Range ◽  
Working Temperature ◽  
Lithium Metal Batteries

Time Slicing Method

2011 ◽  
pp. 272-279
Author(s):  
Phillip K.C. Tse
Keyword(s):  
High Throughput ◽  
Storage Capacity ◽  
Low Cost ◽  
Storage Devices ◽  
Access Latency ◽  
Tertiary Storage ◽  
Start Up ◽  
Slicing Method ◽  
Time Slicing

Tertiary storage devices provide huge storage capacity at low cost. Multimedia objects stored on the tertiary storage devices are accessed with high latency. Despite the high access latency, some tertiary storage devices are able to deliver data at high throughput. The time slicing method is designed to reduce the start-up latency in accessing multimedia objects from tertiary storage devices. The start-up latency is lowered by reducing the amount of data being migrated in stage one of the staging method being described in the last chapter. In order to support the time-slicing method, the tertiary storage devices should have the ability to deliver data at high throughput. The tertiary storage devices that cannot deliver data at sufficiently high throughput; the start-up latency cannot be reduced.

START-UP STRATEGY FOR SBR TREATMENT OF COMPLEX INDUSTRIAL WASTEWATER

1994 ◽  
Vol 30 (3) ◽  
pp. 149-155
Author(s):  
M. Muñiz ◽  
A. G. Lavin ◽  
M. Díaz
Keyword(s):  
Industrial Wastewater ◽  
Low Cost ◽  
Process Efficiency ◽  
Normal Operation ◽  
Organic Load ◽  
Feeding Time ◽  
Good Test ◽  
High Salinity Water ◽  
Start Up ◽  
Complex Organic

In SBR processes, the start-up operation is of considerable interest, not only because of the effect of the efficiency on normal operation, but also because of the cost of the transport of sludge seed and the related feeding time with artificial substrate. The selection of the strategy bas not been studied previously as far as we know, although it is a problem of considerable economic importance. This is not only a problem of the relation between seed magnitude and the start-up timing, but also the effect on the process efficiency. The start-up in SBRs is more frequent than in conventional activated sludge when considering SBRs are mainly used for industrial wastewater treatment, where there are more stops and changes of organic load. A start-up strategy for SBR biological treatment of industrial wastewater with several complex organic components, based on two steps (Filling and Conditioning Periods), bas been proposed and put into operation in a pilot plant column. The strategy looks for minimum time to achieve high steady state efficiency, and low cost of implementation, and sludge seeding. It makes a provision for feed on the basis of inhibition potential and organic needs, and introduces instructions during the operation, depending on the results being obtained. The results of this strategy using a complex organic high salinity water are presented. The presence in this case of two types of solvents and very high salts concentration has been a good test problem for the proposed strategy because of the necessity of multiple adaptation of sludge and the considerably difficult problem to be solved.

scholarly journals Experimental Methods for Investigation of Drilling Fluid Displacement in Irregular Annuli

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5201
Author(s):  
Bjørnar Lund ◽  
Ali Taghipour ◽  
Jan David Ytrehus ◽  
Arild Saasen
Keyword(s):  
Electrical Conductivity ◽  
Large Scale ◽  
Drilling Fluid ◽  
Low Cost ◽  
Relevant Information ◽  
Experimental Methods ◽  
Optical Measurements ◽  
Complex Flow ◽  
Large Scale Systems ◽  
Fluid Displacement

Experimental methods are still indispensable for fluid mechanics research, despite advancements in the modelling and computer simulation field. Experimental data are vital for validating simulations of complex flow systems. However, measuring the flow in industrially relevant systems can be difficult for several reasons. Here we address flow measurement challenges related to cementing of oil wells, where main experimental issues are related to opacity of the fluids and the sheer size of the system. The main objective is to track the propagation of a fluid-fluid interface during a two-fluid displacement process, and thereby to characterize the efficiency of the displacement process. We describe the implementation and use of an array of electrical conductivity probes, and demonstrate with examples how the signals can be used to recover relevant information about the displacement process. To our knowledge this is the most extensive use of this measurement method for studying displacement in a large-scale laboratory setup. Optical measurements and visual observations are challenging and/or costly in such large-scale systems, but can still provide qualitative information as shown in this article. Using electrical conductivity probes is a robust and fairly low-cost experimental method for characterizing fluid-fluid displacement in large-scale systems.

scholarly journals Strength and dynamic characteristics analyses of wound composite axial impeller

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Jifeng Wang ◽  
Jorge Olortegui-Yume ◽  
Norbert Müller
Keyword(s):  
Dynamic Characteristics ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Design Parameters ◽  
Modal Shape ◽  
Kevlar Fiber ◽  
Start Up ◽  
High Performance Composite ◽  
Wound Composite

AbstractA low cost, light weight, high performance composite material turbomachinery impeller with a uniquely designed blade patterns is analyzed. Such impellers can economically enable refrigeration plants to use water as a refrigerant (R718). A strength and dynamic characteristics analyses procedure is developed to assess the maximum stresses and natural frequencies of these wound composite axial impellers under operating loading conditions. Numerical simulation using FEM for two-dimensional and three-dimensional impellers was investigated. A commercially available software ANSYS is used for the finite element calculations. Analysis is done for different blade geometries and then suggestions are made for optimum design parameters. In order to avoid operating at resonance, which can make impellers suffer a significant reduction in the design life, the designer must calculate the natural frequency and modal shape of the impeller to analyze the dynamic characteristics. The results show that using composite Kevlar fiber/epoxy matrix enables the impeller to run at high tip speed and withstand the stresses, no critical speed will be matched during start-up and shut-down, and that mass imbalances of the impeller shall not pose a critical problem.

Prospects for the space sector during 2017-22

2016 ◽  
Keyword(s):  
Low Cost ◽  
Content Type ◽  
Small Satellites ◽  
Start Up ◽  
Design Build

Subject Prospects for the space sector during 2017-22. Significance The emergence of a sector known as 'NewSpace' will be a key development over the coming five years. The term describes small start-up companies using off-the-shelf components and low-cost procedures to design, build and launch small satellites quickly -- in contrast to the bureaucratic, high-cost, government-funded programmes known as 'Big Space'.

scholarly journals Investigation of Start-Up Characteristics of Thermosyphons Modified with Different Hydrophilic and Hydrophobic Inner Surfaces

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 765 ◽  
Author(s):  
Xiaolong Ma ◽  
Zhongchao Zhao ◽  
Pengpeng Jiang ◽  
Shan Yang ◽  
Shilin Li ◽  
...  
Keyword(s):  
Contact Angle ◽  
Significant Role ◽  
Smooth Surface ◽  
Hydrophobic Properties ◽  
Two Phase ◽  
Condenser Section ◽  
Chemical Coating ◽  
Evaporator Section ◽  
Wall Superheat ◽  
Start Up

In this paper, the influence of wettability properties on the start-up characteristics of two-phase closed thermosyphons (TPCTs) is investigated. Chemical coating and etching techniques are performed to prepare the surfaces with different wettabilities that is quantified in the form of the contact angle (CA). The 12 TPCTs are processed including the same CA and a different CA combination on the inner surfaces inside both the evaporator and the condenser sections. For TPCTs with the same wettability properties, the introduction of hydrophilic properties inside the evaporator section not only significantly reduces the start-up time but also decreases the start-up temperature. For example, the start-up time of a TPCT with CA = 28° at 40 W, 60 W and 80 W is 46%, 50% and 55% shorter than that of a TPCT with a smooth surface and the wall superheat degrees is 55%, 39% and 28% lower, respectively. For TPCTs with combined hydrophilic and hydrophobic properties, the start-up time spent on the evaporator section with hydrophilic properties is shorter than that of the hydrophobic evaporator section and the smaller CA on the condenser section shows better results. The start-up time of a TPCT with CA = 28° on the evaporator section and CA = 105° on the condenser section has the best start-up process at 40 W, 60 W and 80 W which is 14%, 22% and 26% shorter than that of a TPCT with smooth surface. Thus, the hydrophilic and hydrophobic modifications play a significant role in promoting the start-up process of a TPCT.

scholarly journals Analysis of the Effects of Arc Volt–Ampere Characteristics on Different Loads and Detection Methods of Series Arc Faults

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 323 ◽  
Author(s):  
Qiwei Lu ◽  
Zeyu Ye ◽  
Yilei Zhang ◽  
Tao Wang ◽  
Zhixuan Gao
Keyword(s):  
Fault Detection ◽  
Research And Development ◽  
Hardware Implementation ◽  
Detection Method ◽  
Low Cost ◽  
Experimental Methods ◽  
Experimental Results ◽  
National Standard ◽  
Detection Methods ◽  
The Relationship

Owing to the shortcomings of existing series arc fault detection methods, based on a summary of arc volt–ampere characteristics, the change rule of the line current and the relationship between the voltage and current are deeply analyzed and theoretically explained under different loads when series arc faults occur. A series arc fault detection method is proposed, and the software flowchart and principles of the applied hardware implementation are given. Finally, a prototype of an arc fault detection device (AFDD) with a rated voltage of 220 V and a rated current of 40 A is developed. The prototype was tested according to experimental methods provided by the Chinese national standard, GB/T 31143-2014. The experimental results show that the proposed detection method is simple and practical, and can be implemented using a low-cost microprocessor. The proposed method will provide good theoretical guidance in promoting the research and development of an AFDD.

Sign in / Sign up

Export Citation Format

Share Document