Safety analysis on the water wall in the 350 MW supercritical CFB boiler under sudden electricity failure

Deng, Boyu; Zhang, Man; Lyu, Junfu; Li, Shaohua; Yang, Hairui

doi:10.1016/j.energy.2019.116364

Cited by 9 publications

(5 citation statements)

References 20 publications

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“…Under the condition of no manual intervention, the physical process in the water side would heavily depend on the dynamic response characteristic of a solenoid valve called the pressure control valve (PCV). The PCV is a type of overpressure protection device and is usually installed at the outlet of the superheater [7]. When the main steam pressure exceeds a preset value, i.e., the set pressure, the PCV would jump up to exhaust extra steam to the environment at a rate proportional to its certified capacity to lower the pressure in the steam-water system.…”

Section: Physical Process In the Water Sidementioning

confidence: 99%

“…As for the energy conservation equation, based on the first law of thermodynamics for closed systems, it is formulated as follows [7]:…”

Section: Governing Equations For the Bed Materials In The Furnacementioning

confidence: 99%

“…where Qbt,EHE is the heat flux between the bed materials and tube wall in the EHE, mb,EHE is the mass of the bed materials in the EHE, Cb,EHE is the specific heat capacity of the bed materials in the EHE, and Tb,EHE is the temperature of the bed materials in the EHE. Qbt,EHE consists of two parts as well, i.e., the heat flux between the bed materials and immersed and exposed tube wall in the EHE, and can be determined as (7) where hbt,i,EHE and hbt,e,EHE are the heat transfer coefficients between the bed materials and immersed and exposed tube wall in the EHE, Abt,i,EHE and Abt,e,EHE are the heat transfer areas between the bed materials and immersed and exposed tube wall in the EHE, respectively, and Tt,EHE is the tube temperature of the superheater.…”

Section: Governing Equations For the Bed Materials In The Ehesmentioning

confidence: 99%

“…In this sense, although a couple of studies have been conducted on this topic, there still lacks a convincing conclusion for the safety of the heating surfaces in ultra-supercritical CFB boilers. Deng et al [6,7] established a zero-dimensional model capable of predicting the tube temperature of the water wall during the electricity failure accident; however, the model was only applicable to supercritical CFB boilers without EHEs. Yao et al [8] deeply analyzed the threedimensional temperature field in the furnace of a 170 t/h CFB boiler during the electricity failure accident; however, the physical process in the water side was oversimplified in that work.…”

Section: Introductionmentioning

confidence: 99%

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Safety Analysis on the Heating Surfaces in the 660 MW Ultra-Supercritical CFB Boiler under Sudden Electricity Failure

et al. 2022

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Ultra-supercritical circulating fluidized bed (CFB) boilers are taking up an increasing proportion of the CFB boiler fleet in China, making the safety concern about the heating surfaces in this type of boilers under sudden electricity failure draw more and more attention from the industry. For the time being, however, few studies have made efforts to resolve this concern. Given this, the physical process in a 660 MW ultra-supercritical boiler during the electricity failure accident was precited with a comprehensive model composed of mass and energy conservation equations in this work. The tube temperature of the boiler components with the highest safety risk, i.e., the water wall and a superheater, was obtained to evaluate the safety of the heating surfaces. The results revealed that the tube temperature (about 516 °C and 544 °C) would be obviously lower than the maximum permissible temperature of the tube material (600 °C and 630 °C) even when electricity could be restored at the power plant, indicating that the heating surfaces in the 660 MW ultra-supercritical CFB boilers would generally be recognized to be safe under sudden electricity failure.

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Section: Physical Process In the Water Sidementioning

confidence: 99%

“…As for the energy conservation equation, based on the first law of thermodynamics for closed systems, it is formulated as follows [7]:…”

Section: Governing Equations For the Bed Materials In The Furnacementioning

confidence: 99%

Section: Governing Equations For the Bed Materials In The Ehesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Safety Analysis on the Heating Surfaces in the 660 MW Ultra-Supercritical CFB Boiler under Sudden Electricity Failure

et al. 2022

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“…Wang and Xiao 24 obtained the temperature–time curve of the working fluid under electricity failure on the basis of assuming a constant exhaust velocity for the working fluid. Deng et al 25 have simulated the boiler physical process in a 350 MW supercritical CFB boiler during electricity failure, providing a reference for the necessity of setting up an emergency water supply system for supercritical CFB boilers. Yao et al 26 studied the heat transfer analysis of a fixed bed in a CFB boiler after a sudden electricity failure.…”

Section: Introductionmentioning

confidence: 99%

Experimental study and safety analysis on the heating surfaces in the 660 MW supercritical CFB boiler under sudden electricity failure

Xie

et al. 2022

Energy Science & Engineering

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The necessity of equipping with an emergency water supply system in a supercritical circulating fluidized bed (CFB) boiler has long been a controversial topic in the industry. In this study, the heating surface of a 660 MW supercritical CFB boiler at the Pingshuo Power Station of China Coal Group is taken as the research object. And a boiler electricity failure experiment was accomplished at the power plant, and the variations of thermal parameters during electricity failure were obtained from power plant distributed control system. By analyzing the physical process of the heating surfaces during electricity failure, a mathematical model of heat transfer to the heating surface was established and a calculation program in Fortran language was developed. In this study, the effect of different flow rates and operating times of the supply pumps on the safety of the heating surfaces were then investigated. The numerical simulation results show that an emergency supply pump with a flow rate of 250 t/h, activated within 120 s, ensures the safety of the heating surface. The results of this study have important implications for the selection of emergency supply pumps and the determination of flow rates and pressures for supercritical CFB boilers with external beds.

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Restart-up Performance of a CFB Boiler after a Sudden Power Failure Accident

et al. 2022

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Safety analysis on the water wall in the 350 MW supercritical CFB boiler under sudden electricity failure

Cited by 9 publications

References 20 publications

Safety Analysis on the Heating Surfaces in the 660 MW Ultra-Supercritical CFB Boiler under Sudden Electricity Failure

Safety Analysis on the Heating Surfaces in the 660 MW Ultra-Supercritical CFB Boiler under Sudden Electricity Failure

Experimental study and safety analysis on the heating surfaces in the 660 MW supercritical CFB boiler under sudden electricity failure

Restart-up Performance of a CFB Boiler after a Sudden Power Failure Accident

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Safety analysis on the water wall in the 350 MW supercritical CFB boiler under sudden electricity failure

Cited by 9 publications

References 20 publications

Safety Analysis on the Heating Surfaces in the 660 MW Ultra-Supercritical CFB Boiler under Sudden Electricity Failure

Safety Analysis on the Heating Surfaces in the 660 MW Ultra-Supercritical CFB Boiler under Sudden Electricity Failure

Experimental study and safety analysis on the heating surfaces in the 660 MW supercritical CFB boiler under sudden electricity failure

Restart-up Performance of a CFB Boiler after a Sudden Power Failure Accident

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Safety analysis on the water wall in the 350 MW supercritical CFB boiler under sudden electricity failure