Study on Basic Coal Consumption Characteristics in Dynamic Process of 660MW Ultra-Supercritical Coal-Fired Unit

2020 ◽  
Author(s):  
Junjie Yin ◽  
Ming Liu ◽  
Junjie Yan ◽  
Yongliang Zhao
Keyword(s):  
Steady State ◽  
Consumption Rate ◽  
Constant Load ◽  
Calculation Model ◽  
Dynamic Processes ◽  
Design Calculation ◽  
Coal Consumption ◽  
Steady State Condition ◽  
Load Cycling ◽  
Consumption Rates

Abstract With the spreading of intermittent renewable power, coal-fired power units should cycle frequently to balance the load between power supply side and demand side. Coal consumption of coal-fired units operating in dynamic processes is influenced by many factors, including thermal system, control system, heat storage variation, etc. Therefore, it is very difficult to evaluate the energy efficiency of coal-fired units operating in dynamic processes. It is important to ascertain the basic coal consumption rate in dynamic processes, which is the basis to evaluate the operation performance of coal-fired units. In this study, an off-design calculation model of 660MW ultra-supercritical coal-fired unit is developed and validated with design parameters. The developed model can be used to predict the coal consumption rates under steady-state off-design conditions. The basic coal consumption means the coal consumption of coal-fired units with operating parameters the same as target values. To calculate the basic coal consumption rate, a load cycling process is differentiated into lots of short time periods and every period is regarded as a steady-state condition with constant load, therefore the coal consumption rates in every period are equal to that of the corresponding steady-state condition. The calculation formula of basic coal consumption rates in is derived for load cycling processes. On the basis of the off-design calculation model and assumption of idealized condition, average coal consumption rates during different processes with constant load cycling rates can be calculated and analyzed. Results show that if the initial and final loads are both settled, the basic coal consumption rate remains unchanged and is independent of load cycling rate. If the load cycling amplitude remains unchanged, the basic coal consumption rate increases as the initial load decrease. The study aims to provide benchmark values for the energy consumption analysis in actual dynamic processes, and further study on coal consumption characteristics in dynamic processes will be developed based on it.

Analysis on Thermal Economy and Peak-Shaving Capability for Combined Heat and Power (CHP) Unit in Varying Operating Conditions

2014 ◽  
Vol 521 ◽  
pp. 508-515 ◽  
Author(s):  
Chun Guang Tian ◽  
Xiang Yu Lv ◽  
De Xin Li ◽  
Tian Dong ◽  
Xiao Juan Han
Keyword(s):  
Heat Supply ◽  
Consumption Rate ◽  
Calculation Model ◽  
Operating Conditions ◽  
Coal Consumption ◽  
Peak Shaving ◽  
Steam Extraction ◽  
Heat Quantity ◽  
Operation Test ◽  
Current Area

Based on the principle of featured through-current area being constant, calculation model for parameters of regenerative steam extraction of CHP unit in different heating conditions is developed in this paper through using FROTRAN software. The generated output and thermal economy of the CHP unit are calculated by using the method of equivalent enthalpy drop, and the accuracy of the model is verified. With the purpose to analyze the rationality of different calculation methods, the distribution ratio of coal consumption for heat supply and coal consumption rate for power generation are calculated through method of equivalent enthalpy drop, heat quantity method and method of actual enthalpy drop under the same operating condition. Moreover, according to the operation test on the unit, the highest and lowest generated output of the CHP under various loads of heat supply are determined, which will provide a basis to the subsequent thermoelectric units in participating in peak shaving of power grid.

Microscopic Driving Parameters-Based Energy Consumption Rate Comparison between Electric Vehicle and Gasoline Vehicle

2013 ◽  
Vol 361-363 ◽  
pp. 2088-2091 ◽  
Author(s):  
En Jian Yao ◽  
Zhi Feng Lang ◽  
Yuan Yuan Song ◽  
Yang Yang
Keyword(s):  
Energy Consumption ◽  
Electric Vehicle ◽  
Consumption Rate ◽  
Electricity Consumption ◽  
Coal Consumption ◽  
Gasoline Consumption ◽  
Energy Consumption Reduction ◽  
Light Duty ◽  
Consumption Reduction ◽  
Consumption Rates

Based on the emission and electricity consumption data collected by a light-duty electric vehicle (EV) and a light-duty gasoline vehicle (GV), a set of electricity consumption rate models and gasoline consumption rate models are established with instantaneous speed and acceleration as input parameters of these models contain while the outputs are electricity & gasoline consumption rates. then, the gasoline & electricity consumption rate models are transformed into standard coal consumption rate models based on the conversion formula of standard coal, respectively. Finally, comparisons about standard coal consumption rates are made between EV and GV under different operation modes. The results show that EV has an obvious advantage over GV in energy consumption reduction.

The Study on the Post-Evaluation of Benefits of the Abandon Hydropower

2013 ◽  
Vol 441 ◽  
pp. 277-280
Author(s):  
Xiao Long Tao ◽  
Ya Fu Zhang ◽  
Shan Wang
Keyword(s):  
Economic Benefit ◽  
Consumption Rate ◽  
Thermal Power ◽  
Comparison Method ◽  
Calculation Model ◽  
Absorption Capacity ◽  
Environmental Benefit ◽  
Coal Consumption ◽  
Post Evaluation ◽  
Daily Plan

In allusion to the problem that abandon hydropower computing ignores the grid absorption capacity, the calculation model of the abandon hydropower considering grid absorption capacity is proposed. In generating daily plan for reference, according the quantity that in excess of the plan calculates the abandon hydropower. In the order of each plant coal consumption rate to reduce the thermal power output from high to low. Hydropower to replace this part of thermal power electricity. When the economic benefit and environmental benefit is largest, we calculate the abandon hydropower that can absorbed by the system. Calculate the increasing benefit of the abandon hydropower by the with and without comparison method when a engineering have been operating.

Exercise slightly above the maximal lactate steady state reduces self-efficacy and increases negative affect

2019 ◽  
Author(s):  
James Graeme Wrightson ◽  
Louis Passfield
Keyword(s):  
Steady State ◽  
Negative Affect ◽  
Power Output ◽  
Self Efficacy ◽  
Repeated Measures ◽  
Physiological State ◽  
Constant Load ◽  
Peak Power Output ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State

Objectives: To examine the effect of exercise at and slightly above the maximal lactate steady state (MLSS) on self-efficacy, affect and effort, and their associations with exercise tolerance.Design: Counterbalanced, repeated measures designMethod: Participants performed two 30‐minute constant‐load cycling exercise at a power output equal to that at MLSS and 10 W above MLSS, immediately followed by a time‐to‐exhaustion test at 80% of their peak power output. Self-efficacy, affect and effort were measured before and after 30 minutes of cycling at and above MLSS.Results: Negative affect and effort higher, and self-efficacy and time to exhaustion were reduced, following cycling at MLSS + 10 W compared to cycling at the MLSS. Following exercise at the MLSS self-efficacy, affect and effort were all associated with subsequent time-to exhaustion. However, following exercise at MLSS + 10 W, only affect was associated with time-to exhaustion. Conclusions: Self efficacy, affect and effort are profoundly affected by physiological state, highlighting the influence of somatic states on perceptions and emotions during exercise. The affective response to exercise appears to be associated with exercise tolerance, indicating that the emotional, as well as physiological, responses should be considered when prescribing exercise training.

Design calculation model of oil fluid property parameter knowledge database for production logging

2020 ◽  
Vol 20 (3) ◽  
pp. 951-958
Author(s):  
Wenguang Song ◽  
Qiongqin Jiang
Keyword(s):  
Crude Oil ◽  
Expert Knowledge ◽  
Calculation Model ◽  
Physical Parameters ◽  
Base System ◽  
Design Calculation ◽  
Calculation Methods ◽  
Fluid Property ◽  
Knowledge Base System ◽  
Parameter Values

The fluid property parameter calculation affects the accuracy of the interpretation the accuracy, in the interpretation of the liquid production profile. Therefore, it is particularly important to accurately calculate the physical property parameter values, in the establishment of the fluid property parameter expert knowledge base system. The main physical parameters include the following calculation methods of the oil. The oil property parameter conversion formula mainly studies the formulas such as bubble point pressure, dissolved gas-oil ratio, crude oil volume coefficient, crude oil density, crude oil viscosity, and crude oil compression coefficient. Design expert knowledge base system, it is based on the calculation methods of these physical parameters. A computational fluid property parameter model is constructed by training production log sample data. Finally, the interactive and friendly product interpretation software model was developed in 9 wells’ data. The design calculation model can increase the accuracy to achieve 95% of oil fluid property parameter. Accurately calculate fluid property parameter values.

scholarly journals Computational Performance of Disparate Lattice Boltzmann Scenarios under Unsteady Thermal Convection Flow and Heat Transfer Simulation

Computation ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 65
Author(s):  
Aditya Dewanto Hartono ◽  
Kyuro Sasaki ◽  
Yuichi Sugai ◽  
Ronald Nguele
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Natural Convection ◽  
Lattice Boltzmann ◽  
Numerical Results ◽  
Convection And Heat Transfer ◽  
Steady State Condition ◽  
Physical Systems ◽  
Flow And Heat Transfer ◽  
Computational Performance

The present work highlights the capacity of disparate lattice Boltzmann strategies in simulating natural convection and heat transfer phenomena during the unsteady period of the flow. Within the framework of Bhatnagar-Gross-Krook collision operator, diverse lattice Boltzmann schemes emerged from two different embodiments of discrete Boltzmann expression and three distinct forcing models. Subsequently, computational performance of disparate lattice Boltzmann strategies was tested upon two different thermo-hydrodynamics configurations, namely the natural convection in a differentially-heated cavity and the Rayleigh-Bènard convection. For the purposes of exhibition and validation, the steady-state conditions of both physical systems were compared with the established numerical results from the classical computational techniques. Excellent agreements were observed for both thermo-hydrodynamics cases. Numerical results of both physical systems demonstrate the existence of considerable discrepancy in the computational characteristics of different lattice Boltzmann strategies during the unsteady period of the simulation. The corresponding disparity diminished gradually as the simulation proceeded towards a steady-state condition, where the computational profiles became almost equivalent. Variation in the discrete lattice Boltzmann expressions was identified as the primary factor that engenders the prevailed heterogeneity in the computational behaviour. Meanwhile, the contribution of distinct forcing models to the emergence of such diversity was found to be inconsequential. The findings of the present study contribute to the ventures to alleviate contemporary issues regarding proper selection of lattice Boltzmann schemes in modelling fluid flow and heat transfer phenomena.

Power Flow Calculation Realization in Software for Grids with Four-Phase Power Lines

2014 ◽  
Vol 698 ◽  
pp. 694-698 ◽  
Author(s):  
Dmitry I. Bliznyuk ◽  
Pavel Y. Bannykh ◽  
Alexandra I. Khalyasmaa
Keyword(s):  
Steady State ◽  
Power Flow ◽  
Calculation Model ◽  
Power Lines ◽  
Power Flow Calculation ◽  
Steady State Analysis ◽  
Flow Calculation ◽  
Analysis Methods ◽  
Electrical Grids ◽  
Three Phase

The paper is devoted to the problem of power flow calculation and steady state analysis methods adaptation for four-phase electrical grids. These methods are based on developed models of four-phase power lines and phase convering transformers. The basis of research is nodal voltages equations for three-phase, four-phase and mixed (combined by three-and four-phase elements) grids. Algorithm of four-phfase elements parameters automized adaptation for power flow calculation model of "RastrWin" software have been developed.

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