Main Power Stations Research Articles

Study of Heat Transfer Rate in Electric Evaporators of Liquefied Petroleum Gas Using Electrothermal Modeling

In modern domestic and foreign experience of gas power supply to houses and industrial facilities located remotely from the main power station, decentralized gas power supply systems fed with propane-butane mixtures of liquefied petroleum gases from tanks are increasingly used. When using liquefied petroleum gases as the main energy carrier in gas tank systems, they are evaporated artificially in evaporators with an intermediate solid-state or liquid heat transfer agent, under conditions of its natural convection. The main operational characteristic of industrial tube evaporators of propane-butane mixtures of liquefied petroleum gases used for gas power supply from tank installations of housing and communal, industrial and industrial facilities that are remote from the main power supply stations is evaporation capacity. The evaporation capacity of industrial tube evaporators of propane-butane mixtures with a solid-state intermediate heat transfer medium is determined by the heat input from the tubular electric heaters through the aluminum casting layer. Therefore, the study of heat transfer in the solid–state intermediate heat transfer medium-evaporation coil system is the most important prerequisite for the effective operation of industrial tube evaporators of propane-butane mixtures and requires detailed research. To solve the problem of determining the heat transfer resistance between the layers of aluminum casting in contact with the surface of the tubular electric heaters group and the outer evaporation coil surface studies were performed on an electrical model. The average value of the total error of the results of experimental studies on electrothermal modeling is 3.7 %, with a confidence probability of 95 %. Recommendations are given for reducing the thickness of the layers in clear from the lower coil of the evaporative tube coil to the lower generatrix of the solid-state aluminum mass and the upper coil of the evaporative tube coil to the upper generatrix of the solid-state aluminum mass.

Design of an industrial elevator: Power Station in Zimbabwe

One of the main power stations in Zimbabwe has its generators located 100m underground. Elevators that used to carry people to the underground plant are not functional anymore due to old age and corrosion of the hoist way blade and guide rails. A system with an electromagnet actuator attached to the elevator car and its core shaped in the form of the letter ‘E’ used for coupling the magnetic flux between the coil and the hoist way rail blades was designed. Pairs of coils are wound on the actuator core in a manner that produces both side-to-side and front-to-back forces that are controlled by adjusting the current being supplied to the coils. The electromagnets fixed to the car supply the force of attraction between the actuator and guide rail, which then keep the car suspended; the motor is used to provide a driving force for the up and down movement of the car. The research satisfied the 9th Sustainable Development Goal of 2015, thereby contributing towards sustainability.

SO2 and NOx Emissions from Kuwait Power Stations in Years 2001 and 2004 and Evaluation of the Impact of These Emissions on Air Quality Using Industrial Sources Complex Short-Term (ISCST) Model

Comprehensive emission inventories for 2001 and 2004 for Kuwait’s main power stations located at Al-Doha and Al-Subyia have been prepared. These inventories are inserted, in conjunction with meteorological data, into the Source Complex model for Short Term Dispersion (ISCST4.5) to predict ambient ground level concentrations of sulphur dioxide (SO2) and nitrogen oxides (NOx) at selected receptors for years 2001 and 2004. The comparison of the results obtained for these 2 years show the influence of increase in emission rates due to urban and industrial growth. For model validation, computed results are compared with the measured daily average values of SO2 and NOx collected at a fixed Kuwait Environment Protection Agency air quality monitoring station located at the roof of polyclinic in Rabia. Individual contributions of each power station to the highest predicted values are assessed. The five highest hourly, daily and annual ground level concentration values under prevailing meteorological conditions are compared for 2001 and 2004. It is found that the hourly mean concentrations are strongly influenced by the prevailing meteorological conditions. The effect of meteorological conditions has not been that dominant for the daily and annual mean values and the predicted values for 2004 are higher than 2001, simply corresponding to a high emission rates, especially in summer months. Top 50 daily average values of SO2 show a slope of 0.806 for 2001 which means that the model predictions are 20% less than the observed levels. However, the predicted slope of SO2 for 2004 is 0.96 and the model predictions are in very close agreement with the observed data.

Impact of Emissions from Power Stations on the Ambient Air Quality of Selected Urban Areas in Kuwait

In Kuwait, two main power stations, one comprising of seven-300MW steam generators at Doha and other with eight-300MW steam generators at Subyia cover the major power requirement of Kuwait city. These stations used different types of fuel oil as the prime source of energy that has different sulpher contents (S%). Comprehensive emission inventories for year the 2001 were used to execute Source Complex model for Short-term Dispersion (ISCST4.5) to predict ambient ground level concentrations of sulphur dioxide (SO2) and nitrogen oxide (NOx) at selected receptors. A yearlong meteorological data were used in conjunction with the dispersion model to compute SO2 and NOx levels in and around the power stations. For validation of the model, computed results were compared with the measured daily average values at a fixed Kuwait EPA air quality monitoring station located at the roof of polyclinic in Rabia residential area. Contributions of each power station to the highest predicted values were assessed. Significance of the fifty highest hourly, daily and annual ground level concentration values under existing meteorological conditions was analyzed. The results for year 2001 revealed that daily and annual mean predicted SO2 concentrations had exceedance about 5.7% and 0.16% respectively of the total area under investigation. Based on these results, mitigation strategies would be proposed to abate high pollution levels caused by these power stations.

Massive use of pulverised fuel ash in concrete for the construction of a U.K. power station

This paper describes the incorporation and benefits of pulverised fuel ash (PFA) in nearly 620,000 m 2 of concrete used in the construction of the U.K.'s first commercial pressurised light water nuclear reactor power station, Sizewell B, Suffolk. Overall nearly 100,000 t of PFA, 1300 t of sintered fly ash lightweight aggregate, and nearly 137,000 t of Ordinary Portland Cement (OPC) were used in the works. Generally in the construction of the main power station buildings, structural concrete with a characteristic strength of 45 N/mm 2 was placed and included fly ash as 40% of the cementitious component. Also, concrete with fly ash as 50% of the cementitious component was placed as mass fill. The programme of research is reported, including sulphate resistance, heat of hydration, elastic properties, alkali-silica reaction, and long-term strength test results. Test and field results are presented and discussed. Strict quality assurance procedures were enforced and statistical summaries are offered to give an insight into the quality of control exercised. Test work and long-term results are also outlined.

Levels of trihalomethanes in the blended water of Bahrain

The distribution of trihalomethanes in the water of the two main power stations and the 10 blending stations in Bahrain has been studied. Total trihalomethanes in the drinking water averaged 2.95 μg/l. Average concentrations (μg/l) of individual compounds were: CHBr 3, 2.17 ± 0.3; CHBr 2Cl, 0.48 ± 0.14; CHBrCl 2, 0.30 ± 0.13.

Intermediate size pressure vessel programme (ZB 1)

One of the focal points in the discussion about the safety of nuclear power plants is the integrity of the reactor pressure vessel. In order to prove its integrity tests are in progress in an underground test facility of the main power station in Mannheim with an intermediate size vessel from the research programme “Integrity of Components”. Patches of A 533 B and modified A 508 B material were welded into the vessel ZB 1, the test temperatures are approximately 70 and 290°C. The main goal of the tests is to measure the behaviour of artificial and natural flaws during static hydrotests and simulated operational (cyclic) conditions. In the first half of the research programme the objective is to produce a crack growth of some centimetres by cyclic loading between a variable minimum pressure and a maximum pressure of about 24 MPa. The total number of load cycles will be approximately 30 000. In the second half of the tests the vessel will be loaded by a number of pressure cycles which correspond to the loading a reactor pressure vessel experiences during 40 years of operation. During the static and cyclic loading acoustic emission monitoring is being made by German and American laboratories. This paper presents details of the vessel, the test loop, results of the nondestructive examinations conducted to quantify the crack depths and results of the acoustic emission monitoring.

Civil Engineering in Steam Electric Plant Design

The problems of steam electric plant design that concern the civil engineer are many and varied. This paper examines the layout of main power station and station yard, substructure, superstructure, coal-handling systems, and architectural treatment. Each plant design has its own requirements based on the clients experiences in operating departments, location of plant, type of fuel, and plans for future expansion. Although there are other matters of concern, emphasis has bene placed on matters that are of a general nature on most engineering jobs of this type. Additional subjects that must always be engineered and that are outside the general realm of this program include surveying, specification writing, comparisons of bids and recommendations to clients, concrete and steel inspections and tests, backfill and consolidation requirements, monthly progress reports, periodic visits to the job for job consultations and inspections, and meetings with client to determine specific needs and general policies. These might well be the subjects of future consideration.

Combustible Material in Electric Power Stations

EABLY in this century, after a fire at Bristol, rubber-covered cables for switchboard work were rarely used. The recent inquiry on the fire at the Kingston Power Station should accelerate the demand for the use of non-combustible materials alone in main power stations. It was stated in evidence that about 850 gallons of inflammable oil and about 14,000 Ib. of solid compound fed the flames. Fires due to oil have been perhaps more numerous in America and Germany than in Great Britain; but recent events show the necessity of getting control of a fire in a power station at the earliest possible moment. The modern oil circuit-breaker (switch) has proved very trustworthy in practice. At its rated capacity it will clear any electric faults with certainty; but in very exceptional circumstances it may fail. The chiefs of supply stations are now paying great attention to the problem of oil-less circuit breakers. Several foreign makers have for the last few years been successfully producing oil-less breakers, particularly the A.E.G. Co. in Berlin, the Brown-Boveri Co. and the Oerlikon Co. in Switzerland. The A.E.G. Co. manufactures a special breaker called a chemical resin breaker for service in unattended substations where the air-blast type could not receive adequate supervision and maintenance. A very profitable and urgent line of inquiry for the industrial research worker would be to try to discover non-combustible liquids and solids of high insulating value for transformers, switches and electric wires. Some fairly satisfactory liquids and compounds have been found, but their cost at present is far too high for use in bulk. It is all a matter of finance. Textile glass has recently been invented. It seems probable that as a wrapping for electric wires it will have a great future.