Vibration Briquetting of Ash of Combined Heat and Power Plant

Ash and slag materials of combined heat and power plant (CHPP) are a unique resource that can be successfully used in construction, road and agricultural industries. However, their industrial use is accompanied with significant organizational and technical problems. Granulation of coal ashes improves the conditions of their storage and transportation, allows mechanizing and automating the subsequent use, increases productivity, improves the working conditions and reduces the loss of raw materials and finished products. This paper proposes a method of compacting of Seversk CHPP (Russia) ash by vibration briquetting using a number of binders (polyvinyl alcohol, glyoxal, liquid sodium glass). The main characteristics of Seversk CHPP ash such as chemical composition, particle size distribution, bulk density, content of unburnt carbon and radioactivity have been determined. Investigation of the effect of binder concentration on the static strength of granules revealed that the increase of binder concentration results in the growth of static strength of the dried granules that reaches a maximum at the concentration of 10 wt %: 0.28 MPa for polyvinyl alcohol, 0.63 MPa for glyoxal and 0.40 MPa for liquid sodium glass

Vibration Briquetting of Ash of Combined Heat and Power Plant

Ash and slag materials of combined heat and power plant (CHPP) are a unique resource that can be successfully used in construction, road and agricultural industries. However, their industrial use is accompanied with significant organizational and technical problems. Granulation of coal ashes improves the conditions of their storage and transportation, allows mechanizing and automating the subsequent use, increases productivity, improves the working conditions and reduces the loss of raw materials and finished products. This paper proposes a method of compacting of Seversk CHPP (Russia) ash by vibration briquetting using a number of binders (polyvinyl alcohol, glyoxal, liquid sodium glass). The main characteristics of Seversk CHPP ash such as chemical composition, particle size distribution, bulk density, content of unburnt carbon and radioactivity have been determined. Investigation of the effect of binder concentration on the static strength of granules revealed that the increase of binder concentration results in the growth of static strength of the dried granules that reaches a maximum at the concentration of 10 wt %: 0.28 MPa for polyvinyl alcohol, 0.63 MPa for glyoxal and 0.40 MPa for liquid sodium glass

Operational flexibility of combined heat and power plant with steam extraction regulation

This paper evaluates the potential for flexible operation of combined heat and power plants, using previously validated steady-state and dynamic process models. The models compute the change in power and heat generation, as well as the response times of steam turbine extraction regulation. It is found that for small-to-medium sized plants, steam bypass could be a promising solution for regulation of power output, also in combination with boiler load changes. Rise times for load reductions by valve opening are within 30 s, independent of the extracted flow, and steam extractions/bypass can lead to power output reductions of up to 30% of rated power. However, plant specific design aspect may limit the achievable magnitude of load changes and must be considered

Determining Reliability Parameters for a Closed-Cycle Small Combined Heat and Power Plant

The paper provides numerical values of the reliability parameters for independent power sources within the ambient temperature and output power range corresponding to the operation under the climatic conditions of Eastern Siberia and the Far East of the Russian Federation. We have determined the optimal values of the parameters necessary for the reliable operation of small CHP plants (combined heat and power plants) providing electricity for isolated facilities

Combined heat and power plant flexibility - Technical and economic potential and system interaction

The share of variable renewable energy sources in electricity generation systems is expected to increase, leading to increased variability in the load that must be provided by conventional power plants or other flexibility measures. Thus, thermal power plants need to consider implementation of technical measures that enhance flexibility; to maintain profitability of operation with increased electricity price fluctuation, and to support electricity system stability. This thesis investigates the technical and economic potential for flexible operation of combined heat and power plants that deliver heat to district heating networks; in current and future Swedish energy system scenarios with varying levels of electricity price volatility. A modeling framework is developed to analyze static, dynamic, technical and economic aspects of flexible combined heat and power operation; comprising steady-state and dynamic process simulation models that are validated with reference plant measurements; and dispatch optimization models. Based on the designs of a waste-fired and a gas turbine combined cycle reference plant, two options to enhance the plant operational flexibility are analyzed: 1) product flexibility; i.e. operating the steam cycle with varying product ratios of electricity, heat and frequency response; 2) thermal flexibility, allowing the heat production to be shifted in time.The results show that flexible operation, for variable electricity generation, is technically feasible in both plant types. Operation with product and/or thermal flexibility can increase the annual plant revenue with up to 90 k€/MW by reduced fuel consumption or increased full load hours. The economic impact of increased ramp rate (operational flexibility) is marginal (<6 k€/MW). The value, and utilization, of flexibility enhancing measures increase with electricity price volatility, that benefits plants with a wide load span for electricity generation and motivates a shift in operating strategy from the traditional heat-following production planning to electricity-following operation

POSSIBILITIES OF ENERGY SAVING AT COMBINED HEAT AND POWER PLANT

This article is about problems of efficiency of modem combined heat and power plants in our country and ways of their solving

Thermodynamic Analysis of the Application of Thermal Energy Storage to a Combined Heat and Power Plant

The main objective of this paper is to show the economic and environmental benefits that can be attained through the coupling of borehole thermal energy storage (BTES) and combined heat and power (CHP). The subject of this investigation is the University of Massachusetts CHP District Heating System. Energy prices are significantly higher during the winter months due to the limited supply of natural gas. This dearth not only increases operating costs but also emissions, due to the need to burn ultra low sulfur diesel (ULSD). The application of a TES system to a CHP plant allows the plant to deviate from the required thermal load in order to operate in a more economically and environmentally optimal manner. TES systems are charged by a heat input when there is excess or inexpensive energy, this heat is then stored and discharged when it is needed. The scope of this paper is to present a TRNSYS model of a BTES system that is designed using actual operational data from the campus CHP plant. The TRNSYS model predicts that a BTES efficiency of 88% is reached after 4 years of operation. It is concluded that the application of BTES to CHP enables greater flexibility in the operation of the CHP plant. Such flexibility can allow the system to produce more energy in low demand periods. This operational attribute leads to significantly reduced operating costs and emissions as it enables the replacement of ULSD or liquefied natural gas (LNG) with natural gas

Опалювальна ТЕЦ потужністю 500МВт, для міста Києва. Пускові режими теплофікаційних енергоблоків

типу на надбандажні ущільнення сотового типу, що надасть можливість підвищити внутрішній відносний ККД турбоагрегату. За допомогою техніко-економічного розрахунку було проведено порівняльний аналіз варіантів вибору основного обладнання ТЕЦ та визначено оптимальний (економічно найвигідніший) варіант. А також було проведено розрахунок теплової схеми, вибір основного і допоміжного обладнання та екологічний розрахунок. Проект має графічну частину, яка складається з восьми креслень: - теплова схема; - план головного корпусу ТЕЦ ; - генеральний план ТЕЦ, - схема головних електричних з’єднань; - поперечний розріз корпусу; - функціональна схема КПВ пароводяного котла ТГМП-344А; - проточна частина ЦВТ турбіни Т-250/300-240; - плакат №1;Modernization of the turbine T-250/300-240 by replacement of overband seal of labyrinth type on overband seal consolidations of cellular type that will give an opportunity to increase the internal relative efficiency of a turbine unit. By means of technical and economic calculation the comparative analysis of options of the choice of the capital equipment of combined heat and power plant was carried out and are defined optimum (economically the most favorable) option. And also calculation of the thermal scheme, the choice of the capital and service equipment and ecological calculation was carried out. The project has a graphic part which consists of eight drawings: - thermal scheme; - plan of the main building of combined heat and power plant; - master plan of combined heat and power plant, - the scheme main electric connections; - case cross-section; - function chart of KPV of a steam-and-water copper ТГМП-344А