It is presented that a feasibility assessment of solar preheating of steam boiler feed water for opened vapor systems. Data from a medium sized dairy industry near Rio de Janeiro city, in Brazil, is used to compose a ...It is presented that a feasibility assessment of solar preheating of steam boiler feed water for opened vapor systems. Data from a medium sized dairy industry near Rio de Janeiro city, in Brazil, is used to compose a case study. Forty eight solar heating system computer simulations were carried out in TRNSYS （transient system simulation software）, for a range of design parameters corresponding to the 5% best economic results of a series of 2,700 simpler simulations （φ,f-chart method）, programmed on Matlab. It has been used TMY （typical meteorological year） hourly weather data from Rio de Janeiro. Investment cost was composed from both commercial and literature values, while revenue was based on the avoided consumption of fuel for LPG （liquefied petroleum gas）, natural gas and fuel oil, with only the first showing economically feasible. The results, however, made it possible to address environmentally sound public policies to encourage industrial solar energy use.展开更多
In order to expand the study on flow instability of supercritical circulating fluidized bed(CFB) boiler,a new numerical computational model considering the heat storage of the tube wall metal was presented in this pap...In order to expand the study on flow instability of supercritical circulating fluidized bed(CFB) boiler,a new numerical computational model considering the heat storage of the tube wall metal was presented in this paper.The lumped parameter method was proposed for wall temperature calculation and the single channel model was adopted for the analysis of flow instability.Based on the time-domain method,a new numerical computational program suitable for the analysis of flow instability in the water wall of supercritical CFB boiler with annular furnace was established.To verify the code,calculation results were respectively compared with data of commercial software.According to the comparisons,the new code was proved to be reasonable and accurate for practical engineering application in analysis of flow instability.Based on the new program,the flow instability of supercritical CFB boiler with annular furnace was simulated by time-domain method.When 1.2 times heat load disturbance was applied on the loop,results showed that the inlet flow rate,outlet flow rate and wall temperature fluctuated with time eventually remained at constant values,suggesting that the hydrodynamic flow was stable.The results also showed that in the case of considering the heat storage,the flow in the water wall is easier to return to stable state than without considering heat storage.展开更多
文摘It is presented that a feasibility assessment of solar preheating of steam boiler feed water for opened vapor systems. Data from a medium sized dairy industry near Rio de Janeiro city, in Brazil, is used to compose a case study. Forty eight solar heating system computer simulations were carried out in TRNSYS （transient system simulation software）, for a range of design parameters corresponding to the 5% best economic results of a series of 2,700 simpler simulations （φ,f-chart method）, programmed on Matlab. It has been used TMY （typical meteorological year） hourly weather data from Rio de Janeiro. Investment cost was composed from both commercial and literature values, while revenue was based on the avoided consumption of fuel for LPG （liquefied petroleum gas）, natural gas and fuel oil, with only the first showing economically feasible. The results, however, made it possible to address environmentally sound public policies to encourage industrial solar energy use.
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences,Grant No.XDA07030100the National Key Technology R&D Program of China during the 12th Five-Year Plan Period No.2015BAA03B01-01
文摘In order to expand the study on flow instability of supercritical circulating fluidized bed(CFB) boiler,a new numerical computational model considering the heat storage of the tube wall metal was presented in this paper.The lumped parameter method was proposed for wall temperature calculation and the single channel model was adopted for the analysis of flow instability.Based on the time-domain method,a new numerical computational program suitable for the analysis of flow instability in the water wall of supercritical CFB boiler with annular furnace was established.To verify the code,calculation results were respectively compared with data of commercial software.According to the comparisons,the new code was proved to be reasonable and accurate for practical engineering application in analysis of flow instability.Based on the new program,the flow instability of supercritical CFB boiler with annular furnace was simulated by time-domain method.When 1.2 times heat load disturbance was applied on the loop,results showed that the inlet flow rate,outlet flow rate and wall temperature fluctuated with time eventually remained at constant values,suggesting that the hydrodynamic flow was stable.The results also showed that in the case of considering the heat storage,the flow in the water wall is easier to return to stable state than without considering heat storage.
