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Malabika Roy ¹, Tanmoyee Banerjee Chaterjee ¹

Affiliations
1 Department of Economics, Jadavpur University, Kolkata - 700 032, IN

Abstract

Based on a primary survey conducted in 2010 in the five villages of West Bengal, India under two gram panchayats located in the district of North 24 Parganas, the present study attempts to identify the variables that improve the possibility of financial inclusion. To judge the extent of financial inclusion we use a scoring methodology usually used in psychology. Then based on the scores the sample is divided into three mutually exclusive categories and multinomial logit regression is used to identify the factors leading to a higher score.

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Arvind Kumar ¹, Malabika Roy ¹, Janardhana M ¹, Shekhar Kumar M ¹

Affiliations
1 Materials Technology Division, Central Power Research Institute, Bangalore-560 080, IN

Abstract

A power generating utility of 600 MW has reported the failure of boiler tubes after a service life of 265 hours against the design life of 25-30 years. The failure of tubes was reported in Re-heater Inlet Coil tubes which were made up of high strength material alloy of SA 213 T91 grade. These boiler tubes were operating under a high temperature and pressure. The material used for re-heater and super-heater boiler tubes should have enough creep strength to sustain at high temperature and pressure. Even though T91 grade steel has superior quality of metallurgical properties in comparison to low alloy existing material like T11, T12 and T22, T91tube was failed in a short duration. This paper describesthe investigation of the failure of high strength T91 gradereheater tubes in a coal fired thermal power plant. The failure investigation covers visual inspection, dimensional measurement, hardness mapping, oxide scale measurement, microstructural studies, and SEM and EDX analysis of the failed tubes. The analysis reveals that Tube No-3 of re-heater boiler tube failed due to short term overheating and other tubes failed due to secondary damage caused by steam impingement.

Keywords

Re-heater Boiler Tube, Visual Inspection, Grade Identification Of Alloy, Dimensional And Hardness Measurement, Oxide Scale Measurement, Microstructure Analysis

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Arvind Kumar ¹, Malabika Roy ², Janardhana M ³, Shekhar Kumar M. ³

Affiliations
1 Engineering Officer, Central Power Research Institute, Bangalore - 560 080, IN
2 JRF, Central Power Research Institute, Bangalore - 560 080, IN
3 Joint Director, Central Power Research Institute, Bangalore - 560 080, IN

Abstract

Boilers being the heart of any steam generating system, failure of its components,will lead to forced outages of the plant, resulting in heavy economic losses in terms of non–availability of plant.Periodic inspection and assessment of boiler tubes has a great impact on the generation of power and economic status. The assessment of boiler tubes minimizes the risk of forced outage of the power plant. This paper presents the assessment of water wall tubes of thermal power plant to avoid any forced outage due to failure of water wall tubes. The assessment includes non-destructive, destructive and failure analysis of failed tubes. The periodic non-destructive evaluation is performed for the boiler tubes for generation of data for assessing and deciding the integrity of the boiler tubes. Destructive and failure analysis of failed tubes gives the information and helps in identifying the ischolar_main cause of failure and to take preventive action for avoiding forced outage.

Keywords

Water Wall Tube, Forced Outage, Corrosion, Erosion, Deposited Product, Scanner, Hydrogen Damage, Microstructure and EDX Analysis

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Malabika Roy ¹, Arvind Kumar ¹, M. Janardhana ¹

Affiliations
1 Materials Technology Division, Central Power Research Institute, Bangalore, IN

Abstract

Coal combustion in a thermal power plant generates plenty of ashes, which gets melted at high temperature. These melted ashes, i.e. slag, gets deposited on the external surface of the boiler tube in the furnace and stick to it. This slag greatly affect the heat transfer, which leads to reduction in the efficiency of the boiler. Also, slag deposition slowly corrodes the external surface of the tube. In this paper, a typical slag deposited tube was collected from a coal fired thermal power plant and metallographic analysis was carried out on this tube and the results were compared with an unexposed tube of same material, diameter and thickness. It is concluded from the analysis that there are no significant changes in microstructure, hardness values as well as inslag compositions.

Keywords

Boiler tube, slag, micro-structure, coal fired, slag indices

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Saheli Bose ¹, Vivekananda Mukherjee ¹, Malabika Roy ¹

Affiliations
1 Department of Economics, Jadavpur University, IN

Abstract

Does political reservation for the backward communities at the rural local governments (Gram Panchayats in India) help favourable allocation of household public goods (houses, toilets, jobs) to the households belonging to those communities? While the conventional literature answers this question in affirmative, the present paper argues that the re-election motive of the political parties may prevent the elected representative belonging to the disadvantaged community to divert the allocation in favour of her own community, especially when it is in minority in the Panchayat. Thus, the purpose of political reservation may fail. Analysing data from villages in West Bengal, India, for Scheduled Caste (SC) reservation at the Gram Panchayats, we find that the impact of political reservation varies across household public goods. The political compulsion shows up the most in provision of jobs, the benefit of which is recurrent in nature.

Keywords

Household Public Goods, Decentralisation, Gram Panchayat, Political Reservation.

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