A Demonstration Study on a High Performance Vertical Roller Mill for a Pulverized Coal Firing Boiler

2011 ◽  
Author(s):  
Yutaka Takeno ◽  
Hiroaki Kanemoto ◽  
Hideo Mitsui
Keyword(s):  
Power Consumption ◽  
New Technologies ◽  
Thermal Power ◽  
Differential Pressure ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Coarse Particle ◽  
Plant Performance ◽  
Roller Mill ◽  
Vertical Roller

We have developed new technologies to improve particle classification performance of vertical roller mills using a rotary nozzle ring with reverse swirling flow and a louver separator. A rotary nozzle and a louver are installed in primary and secondary classification sections of the mill, respectively. A series of tests using a pilot scale mill showed that these technologies reduce the fraction of coarse particles, power consumption of the mill and mill differential pressure. For an industrial scale-up, we conducted a demonstration test using a vertical roller mill equipped in a 700MW thermal power plant consisting of a pulverized coal firing boiler and six mills with approx. 70t/h nominal grinding capacity in each. In this paper, we discuss demonstration test results on the viewpoint of decreasing coarse particle fractions, power consumption and mill differential pressure. Under normal operating conditions, the coarse particle fraction in pulverized coal was reduced more than 50%, power consumption was reduced 7% and differential pressure was reduced approx. 50%. Additionally, power consumption was reduced approx. 15% under high coal feed conditions. We confirmed that these new technologies effectively improved performance in higher mill loading rates. These results provide a prospect of upgrading the plant performance, especially in reducing unburned carbon in fly ash and power consumption of auxiliary equipment.

A Thermoeconomic Study of Low-Temperature Intercooled-Recuperated Cycles for Pure-Solar Gas-Turbine Applications

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
James Spelling ◽  
Björn Laumert ◽  
Torsten Fransson
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
Gas Turbine ◽  
Thermal Power ◽  
Operating Conditions ◽  
Plant Performance ◽  
Electricity Production ◽  
Trade Offs ◽  
Conflicting Objectives ◽  
Population Based Algorithm

A dynamic model of a megawatt-scale low-temperature intercooled-recuperated solar gas-turbine power plant has been developed in order to allow determination of the thermodynamic and economic performance. The model was then used for multi-objective thermoeconomic optimization of both the power plant performance and cost, using a population-based algorithm. In order to examine the trade-offs that must be made and identify ‘optimal’ plant sizes and operating conditions, two conflicting objectives were considered, namely minimum investment costs and maximum annual electricity production. Levelized electricity costs from a 65 MWe power plant operating at 950 °C are predicted to be below 130 USD/MWhe, competitive with other solar thermal power technologies. Optimal plant sizes and configurations have been identified.

Forecasting of Fouling in Air Pre-Heaters Through Deep Learning

2021 ◽  
Author(s):  
Ashit Gupta ◽  
Vishal Jadhav ◽  
Mukul Patil ◽  
Anirudh Deodhar ◽  
Venkataramana Runkana
Keyword(s):  
Deep Learning ◽  
Power Plants ◽  
Short Term Memory ◽  
Catalytic Reduction ◽  
Thermal Power ◽  
Differential Pressure ◽  
Operating Conditions ◽  
Flue Gases ◽  
Gas Temperature ◽  
Sulphur Oxides

Abstract Thermal power plants employ regenerative type air pre-heaters (APH) for recovering heat from the boiler flue gases. APH fouling occurs due to deposition of ash particles and products formed by reactions between leaked ammonia from the upstream selective catalytic reduction (SCR) unit and sulphur oxides (SOx) present in the flue gases. Fouling is strongly influenced by concentrations of ammonia and sulphur oxide as well as the flue gas temperature within APH. It increases the differential pressure across APH over time, ultimately leading to forced outages. Owing to lack of sensors within APH and the complex thermo-chemical phenomena, fouling is quite unpredictable. We present a deep learning based model for forecasting the gas differential pressure across the APH using the Long Short Term Memory (LSTM) networks. The model is trained and tested with data generated by a plant model, validated against an industrial scale APH. The model forecasts the gas differential pressure across APH within an accuracy band of 5–10% up to 3 months in advance, as a function of operating conditions. We also propose a digital twin of APH that can provide real-time insights into progression of fouling and preempt the forced outages.

scholarly journals Effects of Blade Parameters on the Flow Field and Classification Performance of the Vertical Roller Mill via Numerical Investigations

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Chang Liu ◽  
Zuobing Chen ◽  
Weili Zhang ◽  
Chenggang Yang ◽  
Ya Mao ◽  
...  
Keyword(s):  
Flow Field ◽  
Pressure Difference ◽  
Continuous Phase ◽  
Classification Performance ◽  
Field Analysis ◽  
Discrete Phase Model ◽  
Roller Mill ◽  
Discrete Phase ◽  
Vertical Roller ◽  
Classification Efficiency

The vertical roller mill is an important crushing and grading screening device widely used in many industries. Its classification efficiency and the pressure difference determine the entire producing capacity and power consumption, respectively, which makes them the two key indicators describing the mill performance. Based on the DPM (Discrete Phase Model) and continuous phase coupling model, the flow field characteristics in the vertical roller mill including the velocity and pressure fields and the discrete phase distributions had been analyzed. The influence of blade parameters like the shape, number, and rotating speed on the flow field and classification performance had also been comprehensively explored. The numerical simulations showed that there are vortices in many zones in the mill and the blades are of great significance to the mill performance. The blade IV not only results in high classification efficiency but also reduces effectively the pressure difference in the separator and also the whole machine. The conclusions of the flow field analysis and the blade effects on the classification efficiency and the pressure difference could guide designing and optimizing the equipment structure and the milling process, which is of great importance to obtain better overall performance of the vertical roller mill.

scholarly journals Evaporator Optimization of Refrigerator Systems Using Quality Analysis

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  
Keyword(s):  
Power Consumption ◽  
Operating Time ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Quality Analysis ◽  
Lubricating Oil ◽  
Optimal Operating ◽  
Compressor Piston ◽  
Refrigerator Temperature ◽  
Visualization Experiments

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.

scholarly journals Selection of Heat Pump Capacity Used at Thermal Power Plants under Electricity Market Operating Conditions

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 226
Author(s):  
Milana Treshcheva ◽  
Irina Anikina ◽  
Vitaly Sergeev ◽  
Sergey Skulkin ◽  
Dmitry Treshchev
Keyword(s):  
Electric Power ◽  
Heat Pump ◽  
Heat Load ◽  
Power Plants ◽  
Thermal Power ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Energy Resources ◽  
Thermal Power Plants ◽  
Maximum Heat

The percentage of heat pumps used in thermal power plants (TPPs) in the fuel and energy balance is extremely low in in most countries. One of the reasons for this is the lack of a systematic approach to selecting and justifying the circuit solutions and equipment capacity. This article aims to develop a new method of calculating the maximum capacity of heat pumps. The method proposed in the article has elements of marginal analysis. It takes into account the limitation of heat pump capacity by break-even operation at electric power market (compensation of fuel expenses, connected with electric power production). In this case, the heat pump’s maximum allowable capacity depends on the electric capacity of TPP, electricity consumption for own needs, specific consumption of conditional fuel for electricity production, a ratio of prices for energy resources, and a conversion factor of heat pump. For TPP based on combined cycle gas turbine (CCGT) CCGT-450 with prices at the Russian energy resources markets at the level of 2019, when operating with the maximum heat load, the allowable heat pump capacity will be about 50 MW, and when operating with the minimum heat load—about 200 MW.

Process Mechanics of Vertical Roller Mill Comminution Grinding

1991 ◽  
Vol 113 (4) ◽  
pp. 381-387
Author(s):  
M. P. West
Keyword(s):  
Mechanical Forces ◽  
Roller Mill ◽  
Process Mechanics ◽  
Vertical Roller

A theory is presented which allows calculation of the mechanical forces during comminution grinding of coal and minerals in vertical roller mills.

Integrated Unit Technology for Gas Field Surface Gathering and Transmission

2012 ◽  
Vol 271-272 ◽  
pp. 1328-1345
Author(s):  
Jin Li ◽  
Jian Yang Zhao
Keyword(s):  
Natural Gas ◽  
Power Consumption ◽  
New Technologies ◽  
Ball Valve ◽  
Gas Field ◽  
Pneumatic Control ◽  
Initial Application ◽  
Design Idea

In combination with the author's experiences in design for integrated unit for natural gas field gathering and transmission, this paper describes conventional practices and technical characteristics of integrated unit in the processes of standardization design and modularization establishment and analyzes the initial application of pneumatic control ball valve, wedge-shaped flowmeter and other new technologies for surface facilities in the gas field. As a result, a new design idea is proposed in this paper, i.e., to improve the integration level of surface facilities, to minimize power consumption and maintenance works and to realize unattended work mode.

Research of iron ore grinding in a vertical-roller-mill

2015 ◽  
Vol 73 ◽  
pp. 109-115 ◽  
Author(s):  
Mathis Reichert ◽  
Carsten Gerold ◽  
Andreas Fredriksson ◽  
Göran Adolfsson ◽  
Holger Lieberwirth
Keyword(s):  
Iron Ore ◽  
Roller Mill ◽  
Vertical Roller

scholarly journals Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants

2013 ◽  
Vol 67 (7) ◽  
pp. 1481-1489 ◽  
Author(s):  
R. Barat ◽  
J. Serralta ◽  
M. V. Ruano ◽  
E. Jiménez ◽  
J. Ribes ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Plant Performance ◽  
Biological Nutrient Removal ◽  
Nitrite Oxidizing Bacteria ◽  
Removal Model

This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, apart from nitrite oxidizing bacteria two groups of ammonium oxidizing organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON (Single reactor system for High activity Ammonium Removal Over Nitrite) reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of wastewater treatment plant performance in wider environmental and operating conditions.

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