A Comparative Analysis of Using the pH and Ammonia Calculation Algorithms in the Chemical Monitoring Systems at Thermal Power Plants

Vestnik MEI ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 37-42
Author(s):  
Olga V. Yegoshina ◽  
◽  
Sofiya K. Zvonareva ◽  
Wei Lin Htet ◽  
◽  
...  
Keyword(s):  
Chemical Control ◽  
Power Plants ◽  
Thermal Power ◽  
Ammonia Concentration ◽  
Monitoring Systems ◽  
Mechanical Equipment ◽  
Reliable Operation ◽  
Chemical Monitoring ◽  
Calculation Algorithms ◽  
Comparison Of The Results

The reliability of thermal and mechanical equipment is largely associated with the introduction of cycle chemistry monitoring systems (CCMS). It is the operation of these systems that helps maintain the main parameters within the standardized ranges in a significantly more reliable manner and decrease the failure rate at power plants. Modern CCMSs use, as input information, the data of automatic chemical monitoring, laboratory chemical control, and thermal process parameters. Unfortunately, the large volume of chemical monitoring performed with the help of laboratory chemical control analyzers is a factor that causes less reliable operation of CCMS. The present study is intended for operating staff and employees of design organizations with the aim to decrease the volume of laboratory chemical control and reduce the sampling points load in terms of sampling flowrate. The possibility of applying indirect algorithms for calculating the most widely used indicators, such as pH and ammonia concentration, based on electrical conductivity measurements of direct and H-cationated samples in automatic chemical monitoring systems is considered. The results of calculation carried out using three algorithms for pH and ammonia concentration for laboratory and field conditions are given. A comparison of the results obtained from using three different methods for calculating the standardized indicators proceeding from experimental data is carried out.

Improvement of chemical control in the water-steam cycle of thermal power plants

2011 ◽  
Vol 31 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Vladana N. Rajaković-Ognjanović ◽  
Dragana Z. Živojinovic ◽  
Branimir N. Grgur ◽  
Ljubinka V. Rajaković
Keyword(s):  
Chemical Control ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Water Steam ◽  
Steam Cycle

scholarly journals Investigation of the saturated steam sampling method influence on the sample representativeness in chemical control systems at thermal power plants

2021 ◽  
Vol 2088 (1) ◽  
pp. 012052
Author(s):  
O V Yegoshina ◽  
S K Zvonareva
Keyword(s):  
High Pressure ◽  
Chemical Control ◽  
Power Plants ◽  
Thermal Power ◽  
Steam Line ◽  
Saturated Steam ◽  
Thermal Power Plants ◽  
Sample Representativeness ◽  
Main Steam Line ◽  
Main Steam

Abstract The most important requirement for sampling is the sample representativeness, which is achieved by the design and location choice of sample nozzle, as well as the speed mode and the presence of sharp pressure drops in the saturated steam flow. The Ansys CFX software package simulates the sampling processes saturated steam in power units with low, medium and high pressure boilers which are used on operating thermal power plants. The saturated steam was sampled from low-pressure boiler by a single-strip probe with a Venturi nozzle, from the medium-pressure boiler was sampled by tapping a pipe at 90 to the main steam line, and the steam of the high – pressure boiler was sampled by a wellhead probe. In three sampling cases it is found that of saturated steam, the flow in the sample nozzle loses speed and decreases to values unacceptable for the selection of a representative sample-below tear rate of the moisture film from the surface. It is confirmed that in the industrial sampling conditions, the condition of speeds equality in the main steam line and in the sample nozzle is not met, which leads to a violation of the sample representativeness. The paper studies the change in the composition of the sampled saturated vapor sample after the film formation on the sample’s nozzle wall in relation to power units with ammonia dosing. It was found that the sample received by the chemical control analyzers is depleted due to the formation of a film and the ferrum and ammonia concentration in moisture droplets on the inner surface of the sampling line.

scholarly journals On the issue of choosing a real-time operating system for hardware and software support of industrial and environmental monitoring systems

2021 ◽  
Vol 1 (2) ◽  
pp. 64-81
Author(s):  
D.I. Kovalev ◽  
T.P. Mansurova ◽  
Ya.A. Tynchenko
Keyword(s):  
Operating System ◽  
Environmental Monitoring ◽  
Real Time ◽  
Information Transfer ◽  
Power Plants ◽  
Thermal Power ◽  
Monitoring Systems ◽  
Thermal Power Plants ◽  
Software Support ◽  
Real Time Operating System

The article discusses the features of the operation of environmental monitoring systems. A number of factors are determined that affect the organization of hardware and software support for such systems. The main factors are: the operation of the equipment in real time, various environmental influences, the specifics of the composition of sensors and connections, as well as a complex technology for servicing the equipment in an aggressive technological environment. The listed factors affect the structure, software, hardware components and design of environmental monitoring systems. When creating any complex systems, the distribution of work in time leads to the allocation of various design stages, and the ideas about the system being designed, reflecting its essential properties with varying degrees of detail, determine the constituent parts of the design process. The specificity of the stages for monitoring systems of thermal power plants is shown, determined both by the general features of these systems and by the peculiarities of their application in the technological processes of thermal power plants, among which the main ones are: the heterogeneity of the input units and devices, as well as technological objects of power plants; work in real time; programmable logic of smart sensors and multifunctional purpose of system components; the possibility of failures leading to a change in the functioning algorithm using the multiversion methodology; the presence of interrelated requirements for the accuracy and speed of information transfer. The work shows the content of work on the stages of designing monitoring systems, taking into account the specifics of their development. This specificity is most significantly manifested in the development of a technical proposal and a draft design. In a step-by-step design, after the end of each stage, an assessment of the main results obtained is carried out by comparing them with those required according to the terms of reference. The article presents an expert analysis that allows you to determine the acceptable implementation of a real-time operating system for hardware and software support for environmental monitoring technologies. Phar Lap ETS, VxWorks and NI Linux Real-Time operating systems are considered.

scholarly journals On the issue of choosing a real-time operating system for hardware and software support of industrial and environmental monitoring systems

2021 ◽  
Vol 1 (2) ◽  
pp. 46-63
Author(s):  
D.I. Kovalev ◽  
T.P. Mansurova ◽  
Ya.A. Tynchenko
Keyword(s):  
Operating System ◽  
Environmental Monitoring ◽  
Real Time ◽  
Information Transfer ◽  
Power Plants ◽  
Thermal Power ◽  
Monitoring Systems ◽  
Thermal Power Plants ◽  
Software Support ◽  
Real Time Operating System

The article discusses the features of the operation of environmental monitoring systems. A number of factors are determined that affect the organization of hardware and software support for such systems. The main factors are: the operation of the equipment in real time, various environmental influences, the specifics of the composition of sensors and connections, as well as a complex technology for servicing the equipment in an aggressive technological environment. The listed factors affect the structure, software, hardware components and design of environmental monitoring systems. When creating any complex systems, the distribution of work in time leads to the allocation of various design stages, and the ideas about the system being designed, reflecting its essential properties with varying degrees of detail, determine the constituent parts of the design process. The specificity of the stages for monitoring systems of thermal power plants is shown, determined both by the general features of these systems and by the peculiarities of their application in the technological processes of thermal power plants, among which the main ones are: the heterogeneity of the input units and devices, as well as technological objects of power plants; work in real time; programmable logic of smart sensors and multifunctional purpose of system components; the possibility of failures leading to a change in the functioning algorithm using the multiversion methodology; the presence of interrelated requirements for the accuracy and speed of information transfer. The work shows the content of work on the stages of designing monitoring systems, taking into account the specifics of their development. This specificity is most significantly manifested in the development of a technical proposal and a draft design. In a step-by-step design, after the end of each stage, an assessment of the main results obtained is carried out by comparing them with those required according to the terms of reference. The article presents an expert analysis that allows you to determine the acceptable implementation of a real-time operating system for hardware and software support for environmental monitoring technologies. Phar Lap ETS, VxWorks and NI Linux Real-Time operating systems are considered.

scholarly journals Air pollution emissions from Chinese power plants based on the continuous emission monitoring systems network

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Ling Tang ◽  
Xiaoda Xue ◽  
Jiabao Qu ◽  
Zhifu Mi ◽  
Xin Bo ◽  
...  
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Estimation Method ◽  
Emission Factors ◽  
Monitoring Systems ◽  
Continuous Emission ◽  
Emission Monitoring ◽  
Level Information ◽  
Plant Emissions ◽  
Continuous Emission Monitoring

Abstract To meet the growing electricity demand, China’s power generation sector has become an increasingly large source of air pollutants. Specific control policymaking needs an inventory reflecting the overall, heterogeneous, time-varying features of power plant emissions. Due to the lack of comprehensive real measurements, existing inventories rely on average emission factors that suffer from many assumptions and high uncertainty. This study is the first to develop an inventory of particulate matter (PM), SO2 and NOX emissions from power plants using systematic actual measurements monitored by China’s continuous emission monitoring systems (CEMS) network over 96–98% of the total thermal power capacity. With nationwide, source-level, real-time CEMS-monitored data, this study directly estimates emission factors and absolute emissions, avoiding the use of indirect average emission factors, thereby reducing the level of uncertainty. This dataset provides plant-level information on absolute emissions, fuel uses, generating capacities, geographic locations, etc. The dataset facilitates power emission characterization and clean air policy-making, and the CEMS-based estimation method can be employed by other countries seeking to regulate their power emissions.

scholarly journals Economizer water-wall damages initiated by feedwater impurities

2014 ◽  
Vol 68 (5) ◽  
pp. 559-563 ◽  
Author(s):  
Sonja Vidojkovic ◽  
Antonije Onjia ◽  
Aleksandar Devecerski ◽  
Nebojsa Grahovac ◽  
Aleksandra Nastasovic
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Plant Stress ◽  
Electric Energy ◽  
X Ray Diffraction ◽  
Reliable Operation ◽  
Water Steam ◽  
Magnetite Layer ◽  
The Cost

The main causes of efficiency loss in thermal power plants are boiler tube failures that diminish unit reliability and availability, and raise the cost of the electric energy. For that reason, regular examination of boiler tubes is indispensable measure for prevention future malfunctions of power units. Microscopic examination of economizer inner wall microstructure, analysis of chemical composition of deposit using x-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) has been performed in a subcritical power plant. Stress corrosion cracking, pitting corrosion, destroyed protective magnetite layer, presence of magnetite and hematite in deposit and corrosive impurities within the cracks were indicated the effect of inadequate quality of feedwater that can not entirely ensure reliable operation of the boiler. It may be stated that maintenance of present boiler does not provide its reliable operation. Extensive chemical control of water/steam cycle was recommended.

scholarly journals Study of the dependences of coal-wood composition, identification of combustion features of the obtained composite materials

2021 ◽  
Vol 2119 (1) ◽  
pp. 012107
Author(s):  
A V Kuznetsov ◽  
E U Gorelikov
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Stationary Mode ◽  
Fuel Processing ◽  
Experimental Conditions ◽  
Experimental Stand ◽  
Mode Of Operation ◽  
Composite Fuel ◽  
Wood Composition ◽  
Comparison Of The Results

Abstract In the study of the combustion of samples, it was found that, other things being equal, under the experimental conditions and with the fixed technical characteristics of the fuel, different parameters of the flame are observed, namely, the speed of reaching a stationary mode, the completeness of fuel combustion, the size and distribution of temperature zones strongly depend on the methods used to carry out the mechanical fuel processing. Comparison of the results showed that under the same experimental conditions, the temperature distribution along the length of the experimental stand, in a stationary mode of operation, is higher for the composite fuel. In the case of composite fuel, 70 percent of the fuel burned up was observed at a 1 m section, which is indicative of these fuel consumption and kindling processes at industrial thermal power plants.

A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

2018 ◽  
pp. 413-418
Author(s):  
Harshkumar Patel ◽  
Yogesh Patel
Keyword(s):  
Fly Ash ◽  
Electricity Generation ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Strength Test ◽  
Partial Replacement ◽  
Pond Ash ◽  
Research Activities ◽  
Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

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