scholarly journals Heat transfer for the boiling crisis in porous systems

2022 ◽  
Vol 1216 (1) ◽  
pp. 012012
Author(s):  
A A Genbach ◽  
H I Beloev ◽  
D Yu Bondartsev ◽  
N A Genbach
Keyword(s):  
Heat Exchange ◽  
Power Plants ◽  
Flow System ◽  
Thermal Power ◽  
Point Of View ◽  
Porous Structures ◽  
Combustion Chambers ◽  
Exchange Processes ◽  
Mesh Structures ◽  
The Ideal

Abstract In this paper we analized and investigated the heat exchange crisis of boiling in porous structures, applicable in thermal power plants. Then we describe the heat exchange processes mechanism and determined the ideal sizes and thicknesses of porous structures. The designed porous structures can be implemented in gas turbine’s nozzles and combustion chambers. From an environmental point of view, the consumption coolant liquid is reduced by ten times in comparison the standard flow system. It’s effectively to develop mesh structures to allow the extension of the critical loads and manage the surface border.

scholarly journals Igniting Soaring Droplets of Promising Fuel Slurries

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 208 ◽  
Author(s):  
Alexander Bogomolov ◽  
Timur Valiullin ◽  
Ksenia Vershinina ◽  
Sergey Shevyrev ◽  
Nikita Shlegel
Keyword(s):  
Combustion Chamber ◽  
Power Plants ◽  
Alternative Fuels ◽  
Complex Geometry ◽  
Thermal Power ◽  
Combustion Chambers ◽  
Fuel Droplets ◽  
Fine Coal ◽  
Active Research ◽  
Burning Coal

High rates of environmental pollution by boilers and thermal power plants burning coal of different grades are the main reason for active research in the world aimed at the development of alternative fuels. The solution to the formulated problem acceptable in terms of environmental, technical and economic criteria is the creation of composite slurry fuels with the use of fine coal or coal processing and enrichment waste, water of different quality, and oil sludge additive. This study considers modern technologies of burning slurry fuels as well as perspective research methods of the corresponding processes. A model combustion chamber is developed for the adequate study of ignition processes. The calculation of the basic geometric dimensions is presented. The necessity of manufacturing the combustion chamber in the form of an object of complex geometry is substantiated. With its use, several typical modes of slurry fuel ignition are determined. Principal differences of ignition conditions of a single droplet and group of fuel droplets are shown. Typical vortex structures at the fuel spray injection are shown. A comparison with the trajectories of fuel aerosol droplets in real combustion chambers used for the combustion of slurry fuels is undertaken.

scholarly journals Selection Ideal Coal Suppliers of Thermal Power Plants Using the Matter-Element Extension Model with Integrated Empowerment Method for Sustainability

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Zhongfu Tan ◽  
Liwei Ju ◽  
Xiaobao Yu ◽  
Huijuan Zhang ◽  
Chao Yu
Keyword(s):  
Evaluation System ◽  
Supplier Selection ◽  
Power Plants ◽  
Thermal Power ◽  
Fuel Quality ◽  
Extension Model ◽  
Development Capacity ◽  
Generation Cost ◽  
Promethee Method ◽  
The Ideal

In order to reduce thermal power generation cost and improve its market competitiveness, considering fuel quality, cost, creditworthiness, and sustainable development capacity factors, this paper established the evaluation system for coal supplier selection of thermal power and put forward the coal supplier selection strategies for thermal power based on integrated empowering and ideal matter-element extension models. On the one hand, the integrated empowering model can overcome the limitations of subjective and objective methods to determine weights, better balance subjective, and objective information. On the other hand, since the evaluation results of the traditional element extension model may fall into the same class and only get part of the order results, in order to overcome this shortcoming, the idealistic matter-element extension model is constructed. It selects the ideal positive and negative matter-elements classical field and uses the closeness degree to replace traditional maximum degree of membership criterion and calculates the positive or negative distance between the matter-element to be evaluated and the ideal matter-element; then it can get the full order results of the evaluation schemes. Simulated and compared with the TOPSIS method, Romania selection method, and PROMETHEE method, numerical example results show that the method put forward by this paper is effective and reliable.

scholarly journals Hydro-reservoir management and unit-commitment in energy optimization

2021 ◽  
Author(s):  
Flávio Leite Loução Junior ◽  
Marlon Sproesser Mathias ◽  
Claudia Sagastizábal ◽  
Luiz-Rafael Santos ◽  
Francisco Nogueira Calmon Sobral
Keyword(s):  
Power Systems ◽  
Demand Response ◽  
Power Plants ◽  
Unit Commitment ◽  
Thermal Power ◽  
Point Of View ◽  
Mixed Integer ◽  
Thermal Power Plants ◽  
Hydro Power ◽  
Optimal Dispatch

In partnership with CCEE, CEPEL and RADIX as industrial partners, in 2021 the study group focused on the dynamics of hourly prices when industrial consumers are demand responsive, as a follow-up of the industrial problem tackled in 2018 and 2019, on ``Day-ahead pricing mechanisms for hydro-thermal power systems''. Demand response is currently being tested by the Brazilian independent system operator and by the trading chamber, ONS. The program considers reductions of consumption of some clients as an alternative to dispatching thermal power plants out of the merit order. The day-ahead problem of finding optimal dispatch and prices for the Brazilian system is modelled as a mixed-integer linear programming problem, with non-convexities related to fixed costs and minimal generation requirements for some thermal power plants. The work focuses on the point of view of an individual hydro-power generator, to determine business opportunities related to adhering to a demand response program.

scholarly journals Comparison of Cooling Systems in Power Plant Units

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6365
Author(s):  
Alexander Genbach ◽  
Hristo Beloev ◽  
David Bondartsev
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Limit State ◽  
Thermal Power ◽  
Economic Effect ◽  
Electrical Power ◽  
Porous System ◽  
Porous Structures ◽  
Cooling Systems ◽  
Power Stations

A new porous system in power plants allowing the management of the crisis of heat exchange at boiling water in porous structures has been investigated. This study refers to the thermal power plants of electrical power stations and devices for cutting natural and artificial mineral media. Combustion chambers and supersonic nozzles were cooled by different porous structures. The optimum cell sizes of the porous structures were determined and data on the heat transfer capacity for the (critical) heat flow were obtained. A thermal device in the form of a rocket-type burner with a detonation jet showed high efficiency for capillary-porous and flow-through cooling systems. The economic effect per burner is not less than 200–300 dollars, and the coolant consumption is reduced by dozens of times, which is environmentally important. A comparative evaluation of the investigated structures and coatings has advantages over other cooling systems. The integration of mesh structures with capillary-porous coatings of natural mineral media produces a synergistic effect of combining them into a technology of their manufacturing, the expansion of critical loads removal and control of the limit state of the coatings.

scholarly journals Identification of Essential Elements in Maintaining Efficient Boiler System of a Coal Fired Thermal Power Plant

2019 ◽  
Vol 9 (2S2) ◽  
pp. 406-410
Keyword(s):  
Electric Power ◽  
Thermal Energy ◽  
Power Plants ◽  
Structural Model ◽  
Thermal Power ◽  
Structural Modeling ◽  
Essential Elements ◽  
Performance Model ◽  
Point Of View ◽  
Interpretive Structural Modeling

Electric power is most inevitable one among the other sources of energy. It plays prime role in all developed and developing countries. More than eighty percentage of the electric power are generated from coal fired thermal power plants, in it the thermal energy available in coal is released by firing inside the boiler and transferred to water to generate the super-heated steam. All the released thermal energy inside the boiler cannot be transferred in to the water. Some percentage of heat energy gets lost to the environment without any beneficial uses. If the boiler maintains and operates in correct way, the losses can be minimized and efficiency can be improved. There are so many enablers to efficiently manage the boiler in both maintenance and operation point of view. By using ISM (Interpretive structural modeling) method, identified the relationships of enabler and they are weak in the interpretation of enabler links. To control this, TISM (Total interpretive structural modeling) is used in this paper and it is a modeling with qualitative technique. For the enablers of boiler system, this method is very useful for creating the performance model in structural form. In addition to this, the interaction between all elements of enablers can be easily identified by developed structural model of this methodology. If most important enablers which influence the efficiency of the boiler is concentrates is very easy to maintain designed efficiency of boiler. This work is narrated in this article.

Analysis of infeasible unit-commitment solutions arising in energy optimization

2022 ◽  
Author(s):  
Leonardo Delarmelina Secchin ◽  
Guilherme Matiussi Ramalho ◽  
Claudia Sagastizábal ◽  
Paulo Silva ◽  
Kenny Vinente
Keyword(s):  
Power Plants ◽  
Unit Commitment ◽  
Thermal Power ◽  
Point Of View ◽  
Mixed Integer ◽  
Fixed Costs ◽  
Unit Commitment Problem ◽  
Optimal Dispatch ◽  
Marginal Costs ◽  
Integer Problem

The day-ahead problem of finding optimal dispatch and prices for the Brazilian power system is modeled as a mixed-integer problem, with nonconvexities related to fixed costs and minimal generation requirements for some thermal power plants. The computational tool DESSEM is currently run by the independent system operator, to define the dispatch for the next day in the whole country. DESSEM also computes marginal costs of operation that CCEE, the trading chamber, uses to determine the hourly prices for energy commercialization. The respective models sometimes produce an infeasible output. This work analyzes theoretically those infeasibilities, and proposes a prioritization to progressively resolve the constraint violation, in a manner that is sound from the practical point of view. Pros and cons of different mathematical formulations are analyzed. Special attention is put on robustness of the model, when the optimality requirements for the unit-commitment problem vary.

Research on Mechanical Engineering with the Design and Implementation of Thermal Power Boiler Soot Blowing Control System

2014 ◽  
Vol 540 ◽  
pp. 394-398
Author(s):  
Xi Juan Wang ◽  
Jun Jie Zhang ◽  
Jing Xiao Feng ◽  
Ming Zhe Zhang
Keyword(s):  
Control System ◽  
Heat Exchange ◽  
System Design ◽  
User Interfaces ◽  
Power Plants ◽  
Thermal Power ◽  
Software System ◽  
Design And Implementation ◽  
Soot Deposition ◽  
Power Boiler

Ash deposition and slagging on boiler heat exchange surfaces is a common phenomenon in fossil fuel fired power plants. In this dissertation, author focuses on the building of soot blowing control system and all of the work is based on a 300MW boiler. This dissertation introduces the endangerment of soot deposition on boiler heat exchange surfaces. In order to reduce the loss due to fouling of the heat exchange surfaces and improve the economic efficiency of the boiler. In this dissertation, author finds the reason about the fouling form and makes analysis on the damage about the soot to thermal power boiler. On the other hand, author make design and implementation of the thermal power boiler soot blowing control system including hardware system design and software system design, and it will be the fundament of soot blowing optimization. The hardware can connect the equipment about the boiler together, and it is the foundation of the control system for thermal power boiler. Based on the data from DAS of power plant and using heating balance theory, this software system puts forwards some graphical user interfaces and that can configure the setting data and monitor the information about thermal power boiler. In this dissertation, author will design and realize the control system about thermal power boiler.

Summary of heat transfer processes and their comparative evaluation for capillary porous coatings in power plants

2019 ◽  
Vol 12 (1) ◽  
pp. 29-35
Author(s):  
A. A. Genbach ◽  
D. Yu. Bondartsev ◽  
A. Y. Shelginsky
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Power Plants ◽  
Cooling System ◽  
Heat Pipes ◽  
High Heat ◽  
Porous Structures ◽  
Heat Exchange Surface ◽  
Exchange Surface ◽  
Thin Fi Lm

The crisis of heat exchange at boiling of water in porous structures used for cooling of heat-stressed surfaces of various aggregates is investigated. The study refers to thermal power installations of power plants. The experiments were carried out on a stand with heat supply from an electric heater. Cooling of heat-exchange surfaces was performed by water supply to porous structures with diff erent cell sizes. It is shown that in porous cooling systems of elements of heat and power plants processes of fl uid boiling take place, and at high heat fl ows it is possible to approach a crisis situation with overheating of the heat-exchange surface. The heat exchange processes are described, the infl uence of thermophysical properties of heat exchange surface is shown, and optimal sizes of porous structure cells are determined. A calculated equation is obtained for determining the critical heat fl ux at high pressures. The calculation of the critical load with respect to the examined porous structures was carried out with taking into account the underheating and fl ow rate, from which it follows that the underheating of the liquid enables to expand slightly the heat transfer capabilities in a porous cooling system. The experimental data of the investigated capillary porous cooling system operating under the joint action of capillary and mass forces are generalized, and its characteristics q=f(ΔT) are compared with boiling in large volume, heat pipes and thin-fi lm evaporators. The limits of diff erent capillary-porous coatings are given. High heat transfer boosting is provided by combined action of capillary and mass forces and has advantages in comparison with boiling in large volume, thin-fi lm evaporators and heat pipes. It is shown that the results of theoretical calculations conform well with experimental data.

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