scholarly journals Design of a Centrifugal Force-Based Speed Sensor for Downhole Turbodrills

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Chuan Wu ◽  
Huafeng Ding ◽  
Lei Han

Turbodrill is an important type of drilling tool. Rotating speed is a key parameter to measure and control the efficiency of a turbodrill. Therefore, it is necessary to measure the rotating speed when a turbodrill is working under a well. However, current speed measurement devices and sensors cannot meet the requirements of the on-site downhole conditions due to many factors, including inadequate sealing, signal interference, difficult installation, and theoretical limitations. To break the aforementioned bottleneck, a new speed sensor used for turbodrills is designed based on the centrifugal force theory. In more detail, the measurement of the speed is performed based on a functional relation between the rotating speed and the centrifugal force of the turbodrill. Besides, the sensor was tested both in-lab and on-site. The test results illustrate that the measurement error is within ±4%, which meets the practical on-site conditions.

Author(s):  
Wu Chuan ◽  
Wen Guojun ◽  
Han Lei

The rotating speed of turbodrill is a key parameter for adjusting the drilling process, which needs to be measured in real time. Based on this, a new rotating speed measurement method used in downhole turbodrill based on the tilt sensor is proposed in this paper. The basic principle is that a periodic signal will be generated by the tilt sensor along with the turbodrill, and then the rotating speed can be obtained by using fast Fourier transform to analyze the output data. Test results show that the measurement error is related to the inclination angle of the borehole, that is, this method cannot be used when the inclination angle is less than 0.4 degrees, while the measurement error is less than 3.5% when the inclination angle is more than 0.4 degrees, which meets the practical requirements. Compared with traditional methods, this method will not be interfered by mud, geological conditions and downhole vibration, and it is also a non-contact measurement method, which is very suitable for downhole environment.


Author(s):  
Helena Pettersson ◽  
Carl Ekstrand ◽  
Anna Hillström ◽  
Inger Lilliehöök

AbstractPrednisolone is used for treatment of inflammatory, allergic, neoplastic, and immune-mediated diseases in dogs. As a glucocorticoid, prednisolone has biochemical effects, which may interfere with the interpretation of biochemistry test results. The aim of this study is to investigate the effects of prednisolone treatment in an anti-inflammatory dose on common biochemical analytes in dogs and to evaluate the clinical relevance of the changes. Ten beagle dogs, enrolled in a cross-over study, were treated with oral prednisolone (1 mg/kg 24 h) for 10 days. Blood samples were collected at day 0, 1, 3, 6, 9, 10, 12, 16, and 20. Data was analyzed using a general linear model with time and treatment as fixed factors. Pairwise comparisons were done between prednisolone and control period for each dog and sampling. Significant results were further evaluated for clinical relevance using laboratory-specific reference intervals and reference change values (RCVs), when available. Statistically significant changes were observed for ALP activity and iron concentration, which increased to levels exceeding the RCV, and several results were outside reference intervals. Phosphate and bile acids increased significantly, while amylase, lipase, and cholesterol decreased significantly, but with mean/median results remaining within reference intervals. Anti-inflammatory prednisolone treatment did not induce significant changes in ALT, GLDH, GGT, cPLI, glucose, or calcium. Treatment with an anti-inflammatory dose of prednisolone induced changes in several analytes. Only the increases in ALP and iron were of such magnitude that they are expected to affect the clinical interpretation of test results.


Author(s):  
Hao Li ◽  
Haipeng Geng ◽  
Bo Wang ◽  
Wei Zheng

In this paper, a rotordynamic experiment on a compressor rotor system is presented and the feasibility of gas foil bearings with inhomogeneous bump foils is verified. A push–pull device is designed to obtain the stiffness curve and the nominal clearance of foil bearings. Operating points and dynamic coefficients of the rotor system at each rotating speed are predicted. In rotordynamic analysis, an alternative model of the impeller is proposed and the critical speed is predicted by employing the finite element method, in which the dynamic coefficients of inhomogeneous foil bearings are taken into account. Compared with the experimental result, the accuracy of the prediction for the critical speed is verified to be about 14% error. Two sets of foil bearings with 22 and 41 μm nominal clearance are manufactured and tested. Test results indicate that the vibration amplitude can be greatly reduced by diminishing the bearing clearance. When foil bearings with 22 μm clearance are used, the high-order harmonic frequencies of rotor vibration are significantly inhibited, and the amplitude of the rotating frequency is obviously restricted. Thus, the foil bearing with inhomogeneous bump foils tested in this paper can meet the speed requirement of the compressor when the nominal clearance is set at 22 μm.


2004 ◽  
Vol 1870 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Tim J. Gates ◽  
Steven D. Schrock ◽  
James A. Bonneson

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Yang Liu ◽  
Shuhan Wang ◽  
Peng Dong ◽  
Xiangyang Xu

An electric oil pump (EOP) was integrated into the hydraulic system and an automatic transmission (AT) mechanical oil pump (MOP) was downsized. These processes were performed to combine a start-stop function with the AT and further improve the transmission efficiency. Furthermore, this study established a dynamics model of power loss and leakage of an 8-speed AT; a flow-based control algorithm of the EOP was then developed to realize the start-stop function and support the MOP to meet the flow requirement of the system. Based on a driving simulation method, sizes of the MOP and EOP that ensured optimal fuel economy were selected. A control strategy for the starting clutch was also developed to minimize the starting delay of the test vehicle. A test environment on a rig and prototype vehicle was established to verify the feasibility of the proposed control strategies. The test results indicated that the transmission functioned favorably with the novel two-pump system presented, and a quick and smooth starting performance was achieved when the engine was restarted. The findings in this study are extremely valuable for forward designs of an AT for realizing start-stop function and improving efficiency.


2017 ◽  
Vol 14 (4) ◽  
pp. 3950 ◽  
Author(s):  
Ahmet Gönener ◽  
Utku Gönener ◽  
Ozan Yılmaz ◽  
Tuğçe Horoz ◽  
Deniz Demirci

The aim of this study is to investigate 8 weeks Thera-Band trainings' effects on male swimmers' 100 m freestyle swimming performance.The study group is created by 20 (n = 20) licenced male athletes that had trained at least 3 days in a week and have been active in swimming sport at least 3 years in Gebze Genclerbirligi Swimming Club 20 (n = 20). Athletes were divided into experiment group (n = 10) and control group (n = 10) randomly. Training programme was applied to the study group for 55-60 minutes for 3 days on alternate days and times when the club does not have swimming training. 12 different Thera-Band trainings were applied for 40-45 mins and each set was 15 minutes.Mann-Whitney U test was used to analyze differences between groups and Wilcoxon signed rank test was applied for analyzing the differences of intra-groups. SPSS 21.0 Statistics package software was used for statistical analyzes. The results show that there are no significantly differences between experimental group's and control group's post test results. (p>0.05). Statistically significant differences are found as a result of intra-group comparison of the experimental group's pre-test and post-test results (p<0.05).Depending on the results obtained after reviewing the literature, it can be concluded that Thera-Band training is effective on the performance improvement of swimmers aged 13-15 years.


2021 ◽  
Vol 4 (1) ◽  
pp. 6
Author(s):  
Alivy Aulia Az Zahra ◽  
Natasha Winona Audrey ◽  
Devalna Siwi Ichyana ◽  
Tania Saskianti ◽  
Seno Pradopo ◽  
...  

Background: Down Syndrome children have better ability in capturing instructions visually. The audio-visual learning method can be applied to Down Syndrome children. Electric toothbrushes were made to make it easier for them to brush their teeth, besides those electric toothbrushes have a handle that is comfortable to hold and control. Purpose: The purpose of this study is to determine the effectiveness of electric and manual toothbrushes on Down Syndrome children OHI-S scores and determine the effect of education on tooth brushing with animated videos on Down Syndrome children OHI-S scores. Methods: Subjects of the study were 34 Down Syndrome children aged 6-19 years in Surabaya, East Java, Indonesia. OHI-S scores were recorded before and after the subjects were educated to brush their teeth with animated videos or dental phantoms. OHI-S scores were also recorded before and after the subjects brushed their teeth using manual toothbrushes or electric toothbrushes. Results: The test results Independent T-test (p> 0.05) showed there was no significant difference between tooth brushing using a manual toothbrush and an electric toothbrush to the decline of OHI-S score of Down Syndrome children. The results of the Mann-Whitney statistical test were p> 0.05, that there was no significant difference in the reduction in OHI-S scores between Down Syndrome children who were educated with animated videos and dental phantoms. Conclusion: There was no significant difference between manual toothbrushes and electric toothbrushes and there was no significant influence of Down Syndrome OHI-S children who were educated with animated videos or dental phantoms.


Author(s):  
Nam Ngo Xuan

A survey of harmful components in some construction sites, 14101 sites in southern province of vietnam. The seven was found between, of which 4 species of insects are recognized as cultural relics including Coptotermes gestroi, Cryptotermes domesticus, Coptotermes ceylonicus và Odontotermes hainanensis. The final result showed that the processing efficiency of 98.6% to reach all varieties Nuisance in ruins, but only 72.59% average of all bond positions after the first treatment and 27 41% position effective treatment after 2nd treatment test results annually showed 97% of relics were treated termites termites not appear again.


Author(s):  
Dodi Sofyan Arief ◽  
◽  
Eko Jadmiko ◽  
Adhy Prayitno ◽  
Muftil Badri ◽  
...  

Dial indicator is a comparison device usually used in industrial activities, especially in production. To make measurements at this time must be supported by technology that can facilitate operators when using it and when analyzing measurement results. Involving the programme and microcontroller are a solution to developing in roundness measurement, and then the results can be more accurate or thorough between the readable values read from the measuring instrument with the actual value of varying the amount of data. Roundness application is a program that can input measurement data automatically and can do calculations directly. Then, it can display a reference circle, a table that calculates the values of X, Y, R, X’, Y’, R’, Roundness Deviation, Run out Concentricity or a shift in the center point and also the center point shift or Theta. In measuring roundness, the test object is used the Standard Mandrel which has been certified by PT. Global Quality Indonesia, by determining three points or positions, namely in the first position the amount of data is 180, in the second position the amount of data is 90 and in the third position, the amount of data is 60 with a rotating speed of 15 mm/s. The results of the reference circle can be seen in each calculation in each position, in the second position the roundness deviation values are approaching of the Mandrel.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Guodong Zhai ◽  
Xujie Qin ◽  
Xing Yang

As a renewable energy source, wind energy has received more and more attention, and the wind power industry has also been advocated and developed by countries all over the world. In the production and use of wind turbines, the design and manufacturing technology of wind turbine bearings is very important. In order to ensure the reliable operation of the wind power main bearing after installation and realize the longest life of it, this paper designs a bearing test bench that can test the performance of the wind power main bearing. It can analyze the temperature, displacement, load, and moment of the key parts of the 5 MW wind power main shaft bearing. The solid modeling of the experimental platform was carried out using the 3D modeling software SolidWorks. Hydraulic loading system and test monitoring system are designed to realize the drive and control of the test bench. Through the established mathematical model, the central load of the hub is converted into the axial cylinder load and the radial cylinder load of the test bench to simulate the actual working conditions of the tested bearing. The test results show that the test bench meets various loading requirements and can reliably complete the task of testing wind power main bearings.


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