scholarly journals An Experimental Study to Determine the Life Time of Naturally Aged Transformer Oil

2005 ◽  
Vol 16 (1) ◽  
pp. 47-63 ◽  
Author(s):  
O. Gouda ◽  
G. Amer ◽  
A. Ibrahim
Keyword(s):  
Experimental Study ◽  
Life Time ◽  
Transformer Oil

An Experimental Study of Free Corrective Heat Transfer in a Parallelogrammic Enclosure

1983 ◽  
Vol 105 (3) ◽  
pp. 433-439 ◽  
Author(s):  
N. Seki ◽  
S. Fukusako ◽  
A. Yamaguchi
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Nusselt Number ◽  
Correlation Equation ◽  
Transformer Oil ◽  
Experimental Measurements ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Prandtl Numbers ◽  
Rayleigh Numbers

Experimental measurements are presented for free convective heat transfer across a parallelogrammic enclosure with the various tilt angles of parallel upper and lower walls insulated. The experiments covered a range of Rayleigh numbers between 3.4 × 104 and 8.6 × 107, and Prandtl numbers between 0.70 and 480. Those also covered the tilt angles of the parallel insulated walls with respect to the horizontal, φ, of 0, ±25, ±45, ±60, and ±70 deg under an aspect ratio of H/W = 1.44. The fluids used were air, transformer oil, and water. It was found that the heat transfer coefficients for φ = −70 deg were decreased to be about 1/18 times those for φ = 0 deg. Experimental results are given as plots of the Nusselt number versus the Rayleigh number. A correlation equation is given for the Nusselt number, Nu, as a function of φ, Pr, and Ra.

On evaluation of thermophysical properties of transformer oil-based nanofluids: A comprehensive modeling and experimental study

2020 ◽  
Vol 300 ◽  
pp. 112249 ◽  
Author(s):  
Ahmadreza Ghaffarkhah ◽  
Masoud Afrand ◽  
Mohsen Talebkeikhah ◽  
Ali Akbari Sehat ◽  
Mostafa Keshavarz Moraveji ◽  
...  
Keyword(s):  
Experimental Study ◽  
Thermophysical Properties ◽  
Transformer Oil ◽  
Comprehensive Modeling

scholarly journals Study of Transformer Lifetime Due to Loading Process on 20 KV Distribution Line

2018 ◽  
Vol 2 (2) ◽  
pp. 25
Author(s):  
A.A.N. Amrita ◽  
W.G. Ariastina ◽  
I.B.G. Manuaba
Keyword(s):  
Residual Life ◽  
Power Transformer ◽  
Short Circuit ◽  
Life Time ◽  
Electric Power System ◽  
Transformer Oil ◽  
Maximum Efficiency ◽  
Iron Core ◽  
Distribution Transformers ◽  
Work Area

Power transformer is very important in electric power system due to its function to raise or lower the voltage according to its designation. On the power side, the power transformer serves to raise voltage to be transmitted to the transmission line. On the transmission side, the power transformer serves to distribute the voltage between the main substations or down to the distribution voltage. On the distribution side, the stresses are channeled to large customers or lowered to serve small and medium customers. As the power transformer is so importance, it is necessary to protect against disturbance, as well as routine and periodic maintenance, so that the power transformer can operate in accordance with the planned time. Some factors that affect the duration of the power transformer is the ambient temperature, transformer oil temperature, and the pattern of load. Load that exceeds the maximum efficiency of the transformer which is 80% of its capacity will cause an increase in transformer oil temperature. Transformer oil, other than as a cooling medium also serves as an insulator. Increasing the temperature of transformer oil will affect its ability as an isolator that is to isolate the parts that are held in the transformer, such as iron core and the coils. If this is prolonged and not handled properly, it will lead to failure / breakdown of insulation resulting in short circuit between parts so that the power transformer will be damaged. PLN data indicates that the power transformer is still burdened exceeding maximum efficiency especially operating in the work area of PLN South Bali Area. The results of this study, on distribution transformers with different loads, in DS 137, DS 263 and DS 363, show that DS 363 transformer with loading above 80% has the shortest residual life time compared to DS 263 and DS 137 which loading less than 80%.

scholarly journals An Experimental Study to Evaluate the Anti-Diarrheal Activity of Bhuvaneshwara Rasa in Wistar Albino Rats

2021 ◽  
pp. 27-35
Author(s):  
Simi Jose ◽  
Chaitra L.V
Keyword(s):  
Experimental Study ◽  
Castor Oil ◽  
Raw Materials ◽  
Life Time ◽  
Drug Group ◽  
Albino Rats ◽  
Test Drug ◽  
Wistar Albino Rats ◽  
Important Disease

Atisara (Diarrhea) is most commonly encountered disease of the present era, due to unhealthy and irregular habits. Atisara (Diarrhea) finds a place as important disease in individual’s life as everyone suffers from it at least once in life time. Bhuvaneshwara rasa is a unique herbo-mineral formulation explained in Bhaishajya ratnavali indicated for all kinds of diarrhea cases. Bhuvaneshwara rasa is a potent formulation having Saindhava, Triphala, Yamani, Bilva peshika and Gruhadhooma. Materials and methods: Raw materials were screened and collected and the formulation selected for the present study Bhuvaneshwara rasa was prepared accordingly. Anti-diarrheal activity of Bhuvaneshwara rasa was evaluated experimentally in albino rats. Experimental study was conducted in 3 groups of animals for anti-diarrheal study each. Anti-diarrheal study was done by castor oil induced diarrhoea and castor oil induced enter-pooling method. Bhuvaneshwara rasa (test drug) and Loperamide are effective in controlling diarrheal episodes. Bhuvaneshwara rasa has shown significant Anti-diarrheal activity in both Castor oil -induced diarrhea and castor oil induced enteropooling, test drug effective than control. Result: Bhuvaneshwara rasa was prepared according to SOP. Test drug group have shown effect experimentally. Conclusion: Bhuvaneshwara rasa is a good anti-diarrheal drug. It can be administered in all types of Atisara.

scholarly journals EFFECT OF REJUVENATORS ON PENETRATION AND SOFTENING POIND OF AGED POLYMER-MODIFIED ROAD BITUMEN

2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Audrius Vaitkus ◽  
Indrė Palionytė ◽  
Rita Kleizienė
Keyword(s):  
Experimental Study ◽  
Physical Properties ◽  
Uv Radiation ◽  
Asphalt Pavement ◽  
Life Time ◽  
Softening Temperature ◽  
Short Term ◽  
Optimal Amount ◽  
Solar Uv

The article describes the effiency of polymer-modified road bitumen regeneration with two types of rejuvenators. Two alternative rejuvenators have been selected aromatic oil Nygen 910 and soft road bitumen V12000. PMB 45/80-55 bitumen, which is used in the upper and lower layers of asphalt pavement, was investigated. During the life time of the asphalt pvement, due to the effects of solar UV radiation, temperature and oxygen, of all the layers of the structure asphalt top layer reaches the highest degree of aging. Short-term and long-term aging were performed to simulate the aging of the bitmen under laboratory conditions. To determine the optimal amount of rejuvenator experiments were performed with 8%, 10% ir 14% rejuvenator by bitumen mass. The effect of rejuvenators were evaluated by studying the main physical properties of bitumen: penetration and softening temperature. Ina n experimental study, aromatic oil was found to be more than 2.5 times more effective than soft bitumen.

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