scholarly journals Use of LNG Cold Potential in the Cogeneration Cycle of Ship Power Plants

2020 ◽  
Vol 8 (9) ◽  
pp. 720
Author(s):  
Zhongcheng Wang ◽  
Sergejus Lebedevas ◽  
Paulius Rapalis ◽  
Justas Zaglinskis ◽  
Rima Mickeviciene ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Numerical Study ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Model And Simulation ◽  
Excess Power ◽  
Liquid Natural Gas ◽  
Cogeneration Cycle ◽  
Regenerative Cycle

This paper presents the results of a numerical study on the parameters that affect the efficiency of the cogeneration cycle of a ship’s power plant. The efficiency was assessed based on the excess power (Ngen.) of a free turbine, operated with the inflow of gaseous nitrogen, which was used to generate electricity. A mathematical model and simulation of the regenerative cycle were created and adjusted to operate with a dual-fuel (diesel-liquid natural gas (LNG)) six-cylinder four-stroke engine, where the energy of the exhaust gas was converted into mechanical work of the regenerative cycle turbine. The most significant factors for Ngen. were identified by parametrical analysis of the cogeneration cycle: in the presence of an ‘external’ unlimited cold potential of the LNG, Ngen. determines an exhaust gas temperature Teg of power plant; the pressure of the turbo unit and nitrogen flow are directly proportional to Ngen. When selecting the technological units for cycle realization, it is rational to use high flow and average πT pressure (~3.0–3.5 units) turbo unit with a high adiabatic efficiency turbine. The effect of the selected heat exchangers with an efficiency of 0.9–1.0 on Ngen. did not exceed 10%. With LNG for ‘internal’ use in a ship as a fuel, the lowest possible temperature of N2 is necessary, because each 10 K increment in N2 entering the compressor decreases Ngen. by 5–8 kW, i.e., 5–6%.

scholarly journals Improving the efficiency of power boilers by cooling the flue gases to the lowest possible temperature under the conditions of safe operation of reinforced concrete and brick chimneys of power plants

2018 ◽  
Vol 245 ◽  
pp. 07014 ◽  
Author(s):  
Evgeny Ibragimov ◽  
Sergei Cherkasov
Keyword(s):  
Reinforced Concrete ◽  
Power Plant ◽  
Flue Gas ◽  
Power Plants ◽  
Thermal Power ◽  
Operating Mode ◽  
Flue Gases ◽  
Technical Solution ◽  
Gas Temperature ◽  
Safe Operation

The article presents data on the calculated values of improving the efficiency of fuel use at the thermal power plant as a result of the introduction of a technical solution for cooling the flue gases of boilers to the lowest possible temperature under the conditions of safe operation of reinforced concrete and brick chimneys with a constant value of the flue gas temperature, when changing the operating mode of the boiler.

Energy Analysis of a Lignite-Fueled Power Plant With a Two-Stage Predrying System

2017 ◽  
Author(s):  
Xin Zhu ◽  
Chang’an Wang ◽  
Chunli Tang ◽  
Defu Che
Keyword(s):  
Power Plant ◽  
Heat Source ◽  
Flue Gas ◽  
Power Plants ◽  
Energy Analysis ◽  
Exhaust Gas ◽  
Two Stage ◽  
Second Stage ◽  
Drying System ◽  
Steam Drying

Performance of lignite-fueled power plants can be improved by predrying the lignite and it is influenced by the characteristics of drying heat source. Heat source for lignite predrying in power plants can be high-temperature flue gas, boiler exhaust gas and extraction steam. Nevertheless, balance point among drying safety, lignite drying degree and drying thermal economy cannot be located using single drying heat source. In this study, a lignite-fueled power plant with a two-stage drying system was proposed. The drying system mainly contains two fluidized bed dryers — the first stage dryer and the second stage dryer. Boiler exhaust gas and extraction steam supply the heat, respectively. The proposed power plant can attain higher lignite drying degree than the power plant in which only boiler exhaust was employed. The new power plant also features higher overall efficiency for the same lignite drying degree compared with extraction steam drying power plant..

scholarly journals Parametric Performance of Combined-Cogeneration Power Plants With Various Power and Efficiency Enhancements

1997 ◽  
Author(s):  
T. Korakianitis ◽  
J. Grantstrom ◽  
P. Wassingbo ◽  
A. F. Massardo
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Steam Injection ◽  
Hot Water ◽  
Plant Performance ◽  
Specific Power ◽  
Specific Rate ◽  
Exhaust Gas ◽  
Design Point

The design-point performance characteristics of a wide variety of combined-cogeneration power plants, with different amounts of supplementary firing (or no supplementary firing), different amounts of steam injection (or no steam injection), different amounts of exhaust gas condensation etc, without limiting these parameters to present-day limits are investigated. A representative power plant with appropriate components for these plant enhancements is developed. A computer program is used to evaluate the performance of various power plants using standard inputs for component efficiencies; and the design-point performance of these plants is computed. The results are presented as thermal efficiency, specific power, effectiveness, and specific rate of energy in district heating. The performance of the simple-cycle gas turbine dominates the overall plant performance; the plant efficiency and power are mainly determined by turbine inlet temperature and compressor pressure ratio; increasing amounts of steam injection in the gas turbine increases the efficiency and power; increasing amounts of supplementary firing decreases the efficiency but increases the power; with sufficient amounts of supplementary firing and steam injection the exhaust-gas condensate is sufficient to make up for water lost in steam injection; and the steam-turbine power is a fraction (0.1 to 0.5) of the gas-turbine power output. Regions of “optimum” parameters for the power plant based on design-point power, hot-water demand, and efficiency are shown. A method for fuel-cost allocation between electricity and hot water is recommended.

Numerical Study on Filtration of Soot Particulates in Gasoline Exhaust Gas by SiC Fiber Filter

2017 ◽  
Vol 735 ◽  
pp. 119-124 ◽  
Author(s):  
Kazuhiro Yamamoto ◽  
Yusuke Toda
Keyword(s):  
Fuel Injection ◽  
Fiber Diameter ◽  
Numerical Study ◽  
Gasoline Direct Injection ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Soot Particles ◽  
Sic Fiber ◽  
Fiber Filter

As for gasoline vehicles, the particulate matter (PM) emissions from traditional port fuel injection (PFI) engines are pretty low. Recently, the gasoline direct injection (GDI) vehicles have been gaining market share globally due to better fuel efficiency, especially in the European countries. A drawback associated with GDI engines is considerably higher PM emissions compared with PFI engines. The soot in gasoline exhaust gas would contribute to urban air pollution, which is deeply related with adverse health effects. For the reduction of PM emission in Europe, a new regulation known as EURO VI has been set recently. Then, we need to trap soot particles in exhaust gas from gasoline automobiles as well as diesel automobiles. However, the gasoline soot would be much smaller than the diesel soot. Also, the gasoline exhaust gas temperature is much higher. Then, we need gasoline particulate filter (GPF) which needs to have better thermal durability. In this study, as a potential GPF, an SiC fiber filter was numerically examined. The effect of the fiber diameter on the filtration was revealed. Results show that, when the filter of the larger fiber diameter is placed more upstream, the deposition of soot particles widely occurs inside the filter, resulting in the lower pressure drop.

Hydrogen-Enriched Methane Combustion Diluted With Exhaust Gas and Steam: Fundamental Investigation on Laminar Flames and NOx Emissions

2017 ◽  
Author(s):  
Charles Lhuillier ◽  
Romain Oddos ◽  
Lisa Zander ◽  
Finn Lückoff ◽  
Katharina Göckeler ◽  
...  
Keyword(s):  
Power Plants ◽  
Numerical Study ◽  
Flame Temperature ◽  
Methane Combustion ◽  
Steam Injection ◽  
High Reactivity ◽  
Stable Operation ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Nox Formation

Hydrogen utilization in conventional power plants can offer a possibility to cover the residual load of volatile renewable energies while at the same time reducing the carbon footprint of power production. The challenge here is the high reactivity of hydrogen posing a risk of flashback, whereas increased flame temperature may result in higher NOx emissions. A promising approach to overcome this challenges is the dilution of combustion mixtures by exhaust gas recirculation or by steam injection. The present paper provides experimental laminar burning velocities of hydrogen-enriched methane/air mixtures diluted with major components of exhaust gas and with steam. The corresponding numerical study based on a fictive species approach is used to quantify the chemical and physical effects of dilution on laminar burning velocities. The influence of hydrogen-enrichment and dilution on NOx formation is studied numerically. The results demonstrate high potential of dilution with steam or exhaust gas to ensure stable operation even for hydrogen-rich mixtures while maintaining low NOx emissions.

Numerical Study of Discharged Heat Water Effect on Aquatic Environment From Coastal Thermal Power Plant by Using Two Water Discharged Pipes

2018 ◽  
Vol 7 (2) ◽  
pp. 97-116
Author(s):  
Alibek Issakhov
Keyword(s):  
Power Plant ◽  
Aquatic Environment ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Numerical Study ◽  
Water Discharge ◽  
Thermal Power ◽  
Numerical Results ◽  
Stratified Medium ◽  
Discharge System

The article presents a numerical study of the thermal load on the aquatic environment by using two water discharge pipes under various operational capacities of thermal power plant. It is solved by the Navier-Stokes and temperature transport equations for an incompressible fluid in a stratified medium. The aim of this article is to improve the existing water discharge system for reduce the heat load on the reservoir-cooler of the thermal power plants operation (Ekibastuz SDPP-1). In this article, thermal pollution using only two water discharge pipes, using the existing one and building only one additional in the eastern part of the reservoir-cooler is numerically simulated. The numerical method is based on the projection method, which was approximated by the finite volume method. The obtained numerical results of three-dimensional stratified turbulent flow for two water discharge pipes under various operational capacities of the thermal power plant were compared with experimental data and with the numerical results for one water discharge pipe.

Numerical study of the influence of geometric form of chimney on the performance of a solar updraft tower power plant

2018 ◽  
Vol 30 (4) ◽  
pp. 685-706 ◽  
Author(s):  
A Jameei ◽  
P Akbarzadeh ◽  
H Zolfagharzadeh ◽  
SR Eghbali
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Numerical Study ◽  
Geometric Form ◽  
Air Velocity ◽  
Hot Air ◽  
Step Procedure ◽  
Parabolic Form ◽  
Tower Height ◽  
Solar Updraft Tower

Today, solar radiation is known as an important renewable energy which can be exploited in several ways such as solar updraft tower power plants, photovoltaic power plants, etc. In a solar updraft tower power plant, sunshine heats the air beneath a wide collector surrounding a tall tower and causes a hot air updraft in the tower by the chimney effect. This airflow drives wind turbines, placed almost in the chimney base, to produce electricity. In this study, the effect of the geometric form of the chimney on the performance of one solar updraft tower power plant is numerically investigated. Regarding the importance of the kinetic power of the hot air on power generation, it is intended to increase the air velocity by varying the forms of the chimney without changing the main dimensions of solar updraft tower power plant such as tower height and collector geometries. This approach may decrease the financial costs of the solar updraft tower power plant. For the numerical simulations, a finite volume computational fluid dynamics code solves the governing equations on an axisymmetric pi-shape domain (15° of whole geometry). To validate the results, the Manzanares solar updraft tower power plant experimental data are utilized. In this study, 15 forms of chimney based on a logical three-step procedure (from a basic cylindrical to a parabolic form) are examined. So, an appropriate/final form with a parabolic curve of chimney wall with divergence angle is obtained. Results indicate that the final form has the highest updraft air velocity. In fact, the average updraft air velocity increases from 15.66 m/s for the basic form to the value of 23.36 m/s (around 49.17% increments) for the final form.

Numerical Study of the Flow Inside a Modular Bag Filter From a Biomass Power Plant

2020 ◽  
Author(s):  
Maria Inês Vinha ◽  
João Silva ◽  
Senhorinha Teixeira ◽  
Ana Gomes ◽  
José Carlos Teixeira
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Numerical Study ◽  
Operating Conditions ◽  
Solid Particles ◽  
Biomass Combustion ◽  
Bag Filter ◽  
First Case ◽  
Vertical Baffle ◽  
Biomass Power Plant

Abstract Nowadays, one of the most important issues in modern industrial power plants is air pollution. Solid particles are harmful to human health and are one of the main pollutants released through the combustion of biomass. The main goal of this paper was to study the flow in a modular bag filter of a dedusting system implemented in a Biomass Power Plant, in order to improve the filtration of the solid particles coming from the biomass combustion. For this purpose, a numerical model using the ANSYS Fluent software was developed. Initially, it was necessary to model the dedusting system in the software SolidWorks. Once this system had 10 modules and to facilitate the simulation in Fluent, only one module was modeled with proper simplifications. Once the geometry was modeled, it was exported to Fluent where the mesh was made, with special care in the inlet of the module, as it is the most critical zone for the simulation. It was simulated 4 cases, where the action of each individual filter was considered. The first case study considered the nominal operating conditions of a biomass power plant. Thereafter, two cases with different mass flow rates were simulated to assess if there were any differences in the flow inside the bag filter. Lastly, it was studied the influence of the vertical baffle size that is in the inlet of the module. Comparing the four simulations, it was concluded that in the first three cases, the flow is very similar, with only a slight increase in the velocity in the study with higher flow, as expected. Furthermore, it was concluded that using a smaller vertical baffle, the flow would be improved, once the filters close to the inlet would be more used.

Demonstration of ORC System Powered by Waste Heat From the Heuksando Island Internal Combustion Diesel Power Plant

2018 ◽  
Author(s):  
Sanghyup Lee ◽  
Hoon Jung
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Heat Source ◽  
Power Plants ◽  
Waste Heat ◽  
Numerical Study ◽  
Cooling Water ◽  
Organic Rankine Cycle ◽  
Operating Conditions ◽  
Source Analysis

Geographical characteristics give the island of Heuksando no choice but to use diesel power generation. This option is not economical, and more than half of the generated energy is released through exhaust gas, cooling water, and other sources of energy loss. In order to reduce these losses and improve power generation efficiency, this research studied Organic Rankine Cycle systems that use waste heat from diesel power plants as a heat source. Unlike previous Rankine cycles, electric power generation and operation are possible because of low heat source and capacity. Cycle design and demonstration-operation logic are required to set the range of waste heat temperature and capacity. In addition, as the overall efficiency may change substantially depending on the efficiency of each component, the operating conditions of various BOPs should be optimized. It is necessary to obtain the optimization and operating conditions of each element of the system through modeling and numerical study of the whole system. In this research, heat source analysis and BOP design were conducted in order to apply the 20kW/30kW ORC systems to the Heuksando Island 1MW diesel power plant. A heat-connecting technique that thermally connects the heat exhaust end piping and the evaporator of the ORC system was developed in this study. The demonstration experiment was conducted sharing the waste heat source with the 20kW and 30kW ORC systems. This paper presents the waste heat analysis and the demonstration operation results of the Heuksando island power plant.

Parametric Performance of Combined-Cogeneration Power Plants With Various Power and Efficiency Enhancements

2005 ◽  
Vol 127 (1) ◽  
pp. 65-72 ◽  
Author(s):  
T. Korakianitis ◽  
J. Grantstrom ◽  
P. Wassingbo ◽  
Aristide F. Massardo
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Steam Injection ◽  
Hot Water ◽  
Plant Performance ◽  
Specific Power ◽  
Specific Rate ◽  
Exhaust Gas ◽  
Design Point

The design-point performance characteristics of a wide variety of combined-cogeneration power plants, with different amounts of supplementary firing (or no supplementary firing), different amounts of steam injection (or no steam injection), different amounts of exhaust gas condensation, etc., without limiting these parameters to present-day limits are investigated. A representative power plant with appropriate components for these plant enhancements is developed. A computer program is used to evaluate the performance of various power plants using standard inputs for component efficiencies, and the design-point performance of these plants is computed. The results are presented as thermal efficiency, specific power, effectiveness, and specific rate of energy in district heating. The performance of the simple-cycle gas turbine dominates the overall plant performance; the plant efficiency and power are mainly determined by turbine inlet temperature and compressor pressure ratio; increasing amounts of steam injection in the gas turbine increases the efficiency and power; increasing amounts of supplementary firing decreases the efficiency but increases the power; with sufficient amounts of supplementary firing and steam injection the exhaust-gas condensate is sufficient to make up for water lost in steam injection; and the steam-turbine power is a fraction (0.1 to 0.5) of the gas-turbine power output. Regions of “optimum” parameters for the power plant based on design-point power, hot-water demand, and efficiency are shown. A method for fuel-cost allocation between electricity and hot water is recommended.

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