A Simple Equivalent Temperature Rise Test Method Suitable for Safely Evaluating Thermal Limits of Motors and Power Devices Without Model Dependence

2020 ◽  
Vol 67 (10) ◽  
pp. 8755-8766
Author(s):  
Baochao Wang ◽  
Shili Dong ◽  
Fei Liu ◽  
Jianhui Hu
Keyword(s):  
Temperature Rise ◽  
Test Method ◽  
Equivalent Temperature ◽  
Power Devices ◽  
Thermal Limits ◽  
Model Dependence

Temperature Rise Real-Time Measurement of Metro Tread Based on the Multi-Sensor Fusion and Online Compensation Method

2017 ◽  
Author(s):  
Jianyong Zuo ◽  
Guo Hu ◽  
Tiefeng Zhao ◽  
Lei Zuo
Keyword(s):  
Temperature Measurement ◽  
Real Time ◽  
Temperature Rise ◽  
Time Measurement ◽  
Test Method ◽  
Sensor Data ◽  
Surface Emission ◽  
Real Time Measurement ◽  
Bright Surface ◽  
Braking Process

To study the temperature rise of the metro wheel tread, the simulation is conducted, finding that the highest temperature emerges in the tread area during the braking process, up to 350 °C. The range of temperature measurement should include 0∼350 °C. The temperature rise of the tread surface and the temperature near the side of the wheel tread tend to be consistent after the braking. The temperature measurement on the side of the wheel can provide a reference for the tread temperature measurement. Then several kinds of temperature sensors used for testing the tread temp are introduced, the accuracy and influencing factors of the measurement of the tread surface temperature sensor was analyzed. For the temperature measurement of wheel tread, featuring bright surface emission, low and unstable emissivity, a real-time temperature test method with multi-sensor compensation and data fusion is proposed and a more realistic curve of the tread temperature is obtained. Taking the actual line pure-air brake condition as an example, the above method is used to measure the temperature of tread surface. The results show that the measurement accuracy of multi-sensor data compensation and fusion is better than that of using the single infrared thermometer method, up by 15%; The law of temperature rise is consistent with that of transient simulation. reflecting that this testing method can offer important references to the real-time measurement of tread temperature.

Adiabatic Temperature Rise of Incompletely Hydrated Cement Concrete

2008 ◽  
Vol 400-402 ◽  
pp. 157-162 ◽  
Author(s):  
P.L. Ng ◽  
I.Y.T. Ng ◽  
A.K.H. Kwan
Keyword(s):  
Temperature Rise ◽  
Cement Content ◽  
High Strength ◽  
Adiabatic Temperature ◽  
Test Method ◽  
Experimental Program ◽  
Test Results ◽  
Prediction Formula ◽  
Adiabatic Temperature Rise ◽  
Water Contents

The temperature rise of concrete during hardening is intimately related to the mix proportion, among which the cement content is a major factor. However, high-strength concrete mixes are often proportioned with low water contents which leads to incomplete hydration of cement contained therein. Hence, the conventional rule of determining concrete temperature rise solely based on the cement content may not yield accurate estimations. An experimental program has been launched to investigate the coupled effects of cement and water contents on the adiabatic temperature rise of concrete. Eighteen concrete mixes were tested with a newly developed semi-adiabatic curing test method and their adiabatic temperature rise obtained by applying heat loss compensation to the test results. The results revealed that, when the water/cement ratio is lower than 0.36, both cement and water contents have effects on the adiabatic temperature rise of concrete. Prediction formula and design chart of adiabatic temperature rise, which are accurate to ±1.3°C compared with the test results, are developed. Furthermore, prediction formula of the degree of hydration of concrete is recommended.

Evaluation of Thermal Integrity Profiling and Crosshole Sonic Logging for Drilled Shafts with Concrete Defects

2019 ◽  
Vol 2673 (8) ◽  
pp. 86-98
Author(s):  
Andrew Z. Boeckmann ◽  
J. Erik Loehr
Keyword(s):  
Temperature Effect ◽  
Temperature Rise ◽  
Maximum Rate ◽  
Drilled Shafts ◽  
Test Method ◽  
Drilled Shaft ◽  
Integrity Test ◽  
Sonic Logging ◽  
Thermal Integrity

Thermal integrity profiling (TIP), which uses temperatures measured along drilled shafts during concrete curing to identify defects, has recently gained favor as an allowable concrete integrity test method for drilled shafts. Drilled shaft concrete temperatures are theoretically sensitive to defects anywhere within the shaft, which presents an opportunity for improving detection over the widely used crosshole sonic logging (CSL) method. This paper describes investigations conducted to compare detectability from TIP and CSL measurements for various types of defects. TIP and CLS measurements are presented for three full-scale drilled shafts constructed with ten intentional defects varying in location, character, and size. Comparison of these measurements indicates TIP and CSL tests are generally complementary with regard to their detection abilities. Each test method is effective for identifying certain types of defects, but limited or incapable of identifying other types of defects. The paper also includes an evaluation of the role of time on the detectability of TIP interpretations, demonstrating that the temperature effect of defects generally peaks around the time of the maximum rate of temperature rise and decreases significantly thereafter.

Adiabatic Temperature Rise of Condensed Silica Fume (CSF) Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 788-795 ◽  
Author(s):  
P L Ng ◽  
W W S Fung ◽  
J J Chen ◽  
A K H Kwan
Keyword(s):  
Silica Fume ◽  
Temperature Rise ◽  
Heat Evolution ◽  
Adiabatic Temperature ◽  
Test Method ◽  
Test Results ◽  
Adiabatic Temperature Rise ◽  
Loss Compensation ◽  
The University ◽  
Condensed Silica Fume

Condensed silica fume (CSF) is often added into concrete mixes to enhance the properties of concrete. However, the effect of CSF on the heat evolution and temperature rise of concrete is not clearly known. Test results in the literature are insufficient and sometimes contradictory to enable any conclusion to be drawn regarding the role of CSF in heat generation behaviour of concrete. Moreover, since the chemical reactions of cement and CSF both involve water and hence cement and CSF are competing with each other in reacting with water, the water to binder (W/B) ratio may affect the temperature rise characteristics of concrete. This paper reports an experimental study of adiabatic temperature rise of CSF concrete conducted at The University of Hong Kong. Five concrete mixes without CSF and 10 concrete mixes with CSF dosages at 5% and 10% were tested with the recently developed semi-adiabatic curing test method. The adiabatic temperature rise was obtained by applying heat loss compensation to the test results. It was found that the addition of CSF could suppress the adiabatic temperature rise of concrete. At the same time, the strength of concrete could be enhanced. Based on the experimental results, prediction formula and design chart of adiabatic temperature rise of CSF concrete were developed.

A Method to Determine the Temperature Rise of Induction Motors

1990 ◽  
Vol 27 (1) ◽  
pp. 45-52 ◽  
Author(s):  
T. F. Chan
Keyword(s):  
Induction Motor ◽  
Temperature Rise ◽  
Induction Motors ◽  
Second Harmonic ◽  
Test Method ◽  
Experimental Results ◽  
Full Load ◽  
Load Conditions

When a voltage comprising a fundamental and a second harmonic of appropriate magnitude is applied to an induction motor which has no coupled load, approximately full-load conditions can be simulated, thus enabling the motor temperature rise to be determined. Circuit arrangements for the proposed test method and experimental results are presented.

scholarly journals An Efficient Testing Scheme for Power-Balanceability of Power System Including Controllable and Fluctuating Power Devices

Designs ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 48
Author(s):  
Saher Javaid ◽  
Mineo Kaneko ◽  
Yasuo Tan
Keyword(s):  
Power Generation ◽  
Power System ◽  
Power Flow ◽  
Power Level ◽  
Power Source ◽  
Test Method ◽  
Level Control ◽  
Power Devices ◽  
Dynamic Power ◽  
Power Fluctuations

Renewable power sources are environmentally friendly power generation systems, such as wind turbines or photovoltaics; however, the output power fluctuations due to the intermittence and variability of these power systems can greatly affect the quality and stability of the power system network. Furthermore, the power fluctuations that are triggered by power load devices also have similar results on the power system. Therefore, it is essential to introduce power level control for controllable power devices and connection in order to lessen the effects of dynamic power fluctuations that are caused by fluctuating power source devices and load devices. The issue of power balancing as a part of power level control presented in this paper assigns power levels to controllable power devices and connections between power source devices and load devices to absorb dynamic power fluctuations. In this paper, we focus on power conservation law instead of detailed voltage or current-based network characterization and present a new power balanceability test for a power flow system that comprises of both fluctuating and controllable power devices. Our proposed power balanceability test can assure the existence of a power flow assignment of power devices and connections for any value of power generation and/or the consumption of fluctuating power devices. Our proposed power balanceability test method can be expressed as a linear programming problem, and it can be resolved in polynomial time complexity.

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