In this paper, FLUENT software was used to simulate the burning process in a utility boiler. Chose the kinetics/diffusion-limited as combustion model, two-competing-rates as devolatilization model, RNG k-εmodel as vi...In this paper, FLUENT software was used to simulate the burning process in a utility boiler. Chose the kinetics/diffusion-limited as combustion model, two-competing-rates as devolatilization model, RNG k-εmodel as viscous model, and PDF model as combustion turbulent flow model. Numerical calculation of NOx formation in a 330 MW cyclone-opposed coal-fired utility boiler with 32 double air registers was done. The distribution characteristics of temperature, NOx and oxygen concentration in furnace were studied. They were symmetrically distributed in furnace. In the combustion area, temperature and NOx concentration are high, while oxygen concentration is low. Temperature and NOx concentration are declined gradually along with furnace height, while oxygen concentration is raised. The higher the temperature is and the greater the excess air coefficient is, the more NOx formation.展开更多
In this study,an active packaging film was developed using polyvinyl alcohol(PVA)incorporated with Bajakah Tampala(BT)extract,which acts as an antimicrobial agent and UV-protective additive.The solution casting method...In this study,an active packaging film was developed using polyvinyl alcohol(PVA)incorporated with Bajakah Tampala(BT)extract,which acts as an antimicrobial agent and UV-protective additive.The solution casting method was employed,with BT extract concentrations ranging from 0.5 to 2 wt%.The BT extract exhibited strong antimicrobial properties and significant UV-protection,with a total phenolic content and IC_(50) values of 242.88±0.34 mg GAE/g and 7.83±0.03μg/mL,respectively.Incorporating 2 wt%BT extract into the PVA matrix resulted in substantial UV-light protection and enhanced tensile strength by 55.1%,tensile modulus by 167.2%,elongation at break by 53.1%,toughness by 84.3%,and crystallinity index by 21.8%.Additionally,the composite film retained moderate antimicrobial and antioxidant activity.These findings demonstrate PVAbased active packaging enriched with BT extract offers promising properties for food packaging applications,including enhanced mechanical strength,UV resistance,barrier performance,and antimicrobial protection.展开更多
基金Supported by Major Project of Tackle Key Problems of Shanghai (Z2003-1)
文摘In this paper, FLUENT software was used to simulate the burning process in a utility boiler. Chose the kinetics/diffusion-limited as combustion model, two-competing-rates as devolatilization model, RNG k-εmodel as viscous model, and PDF model as combustion turbulent flow model. Numerical calculation of NOx formation in a 330 MW cyclone-opposed coal-fired utility boiler with 32 double air registers was done. The distribution characteristics of temperature, NOx and oxygen concentration in furnace were studied. They were symmetrically distributed in furnace. In the combustion area, temperature and NOx concentration are high, while oxygen concentration is low. Temperature and NOx concentration are declined gradually along with furnace height, while oxygen concentration is raised. The higher the temperature is and the greater the excess air coefficient is, the more NOx formation.
基金funded by Universitas Andalas under the project“Riset Kolaborasi Indonesia(Skema A)”,number 3/UN16.19/PT.01.03/PRK-RKI Skema A(Host)/2023。
文摘In this study,an active packaging film was developed using polyvinyl alcohol(PVA)incorporated with Bajakah Tampala(BT)extract,which acts as an antimicrobial agent and UV-protective additive.The solution casting method was employed,with BT extract concentrations ranging from 0.5 to 2 wt%.The BT extract exhibited strong antimicrobial properties and significant UV-protection,with a total phenolic content and IC_(50) values of 242.88±0.34 mg GAE/g and 7.83±0.03μg/mL,respectively.Incorporating 2 wt%BT extract into the PVA matrix resulted in substantial UV-light protection and enhanced tensile strength by 55.1%,tensile modulus by 167.2%,elongation at break by 53.1%,toughness by 84.3%,and crystallinity index by 21.8%.Additionally,the composite film retained moderate antimicrobial and antioxidant activity.These findings demonstrate PVAbased active packaging enriched with BT extract offers promising properties for food packaging applications,including enhanced mechanical strength,UV resistance,barrier performance,and antimicrobial protection.
