针对蓄热式电锅炉能效无法有效评测的问题,提供了一种综合能效测试方法,适用于100 k W以下电阻直热式锅炉、电极式锅炉、电磁式热水锅炉、3立方米以下相变蓄热单元等电加热锅炉系统,通过对蓄热式电锅炉蓄热单元蓄热时间、释热时间、蓄...针对蓄热式电锅炉能效无法有效评测的问题,提供了一种综合能效测试方法,适用于100 k W以下电阻直热式锅炉、电极式锅炉、电磁式热水锅炉、3立方米以下相变蓄热单元等电加热锅炉系统,通过对蓄热式电锅炉蓄热单元蓄热时间、释热时间、蓄热量、释热量、释蓄热量比、蓄热速率、释热速率等指标进行测量计算,解决实际应用过程中电蓄热锅炉系统能效对比评价的问题,可以对蓄热式锅炉产品的设计和优化提供参考。展开更多
Abstract Pyrite has a significant effect on the spontaneous combustion of coal. The presence of pyrite can change the propensity of coal towards spontaneous combustion. The influences of various pyrite contents on the...Abstract Pyrite has a significant effect on the spontaneous combustion of coal. The presence of pyrite can change the propensity of coal towards spontaneous combustion. The influences of various pyrite contents on the parameters of spontaneous combustion, such as index gases, temperature and released heat etc., were investigated in this study, Coal samples with different pyrite contents （0 %, 3 %, 5 %, 7 % and 9 %） were made by mixing coal and pyrite. The oxidation experiments under temperature-programmed condition were carried out to test the release rate of gaseous oxidation products at different temperatures. Differential scanning calorimeter （DSC） was employed to measure the intensity of heat release during coal oxidation for various pyrite contents. The results indicate that pyrite can nonlinearly accelerate the process of spontaneous combustion. The coal sample with a pyrite content of 5 % has the largest CO release rate and oxygen adsorption as well. However, the coal sample with a pyrite content of ？ % has the largest rate of heat flow according to the results from the DSC tests. Pyrite contents of 5 %-7 % in coal has the most significant effects on spontaneous combustion within the range of this study. The conclusions are conducive to the evaluation and control for the spontaneous combustion of coal.展开更多
An extraordinary rainstorm that occurred in Beijing on 21 July 2012 was simulated using the Weather Research and Forecasting model. The results showed that:(1) The two precipitation phases were based on a combination ...An extraordinary rainstorm that occurred in Beijing on 21 July 2012 was simulated using the Weather Research and Forecasting model. The results showed that:(1) The two precipitation phases were based on a combination of cold cloud processes and warm cloud processes. The accumulated conversion amount and conversion rate of microphysical processes in the warm-area phase were all much larger than those in the cold front phase.(2) 72.6% of rainwater was from the warm-area phase. Rainwater mainly came from the melting of graupel and the melting of snow, while the accretion of cloud water by rain ranked second.(3) The net heating rate with height appeared as an overall warming with two strong heating centers in the lower and middle layers of the troposphere and a minimum heating center around the melting layer. The net heating effect in the warm-area phase was stronger than that in the cold front phase.(4) Warm cloud processes contributed most to latent heat release, and the thermal effect of cold cloud processes on the storm in the cold front phase was enhanced compared to that in the warm-area phase.(5) The melting of graupel and snow contributed most to latent heat absorption, and the effect of the evaporation of rainwater was significantly reduced in the cold front phase.展开更多
文摘针对蓄热式电锅炉能效无法有效评测的问题,提供了一种综合能效测试方法,适用于100 k W以下电阻直热式锅炉、电极式锅炉、电磁式热水锅炉、3立方米以下相变蓄热单元等电加热锅炉系统,通过对蓄热式电锅炉蓄热单元蓄热时间、释热时间、蓄热量、释热量、释蓄热量比、蓄热速率、释热速率等指标进行测量计算,解决实际应用过程中电蓄热锅炉系统能效对比评价的问题,可以对蓄热式锅炉产品的设计和优化提供参考。
文摘Abstract Pyrite has a significant effect on the spontaneous combustion of coal. The presence of pyrite can change the propensity of coal towards spontaneous combustion. The influences of various pyrite contents on the parameters of spontaneous combustion, such as index gases, temperature and released heat etc., were investigated in this study, Coal samples with different pyrite contents （0 %, 3 %, 5 %, 7 % and 9 %） were made by mixing coal and pyrite. The oxidation experiments under temperature-programmed condition were carried out to test the release rate of gaseous oxidation products at different temperatures. Differential scanning calorimeter （DSC） was employed to measure the intensity of heat release during coal oxidation for various pyrite contents. The results indicate that pyrite can nonlinearly accelerate the process of spontaneous combustion. The coal sample with a pyrite content of 5 % has the largest CO release rate and oxygen adsorption as well. However, the coal sample with a pyrite content of ？ % has the largest rate of heat flow according to the results from the DSC tests. Pyrite contents of 5 %-7 % in coal has the most significant effects on spontaneous combustion within the range of this study. The conclusions are conducive to the evaluation and control for the spontaneous combustion of coal.
基金supported by the National Basic Research Program of China (973 Program, Grant Nos. 2013CB430105 and 2014CB441403)the National Natural Science Foundation of China (Grant No. 41205099)+1 种基金Guizhou Province Scientific Research Joint Project (Grant No. G[2013]4001)the Special Scientific Research Project of Meteorological Public Welfare Profession of China (Grant No. GYHY201006031)
文摘An extraordinary rainstorm that occurred in Beijing on 21 July 2012 was simulated using the Weather Research and Forecasting model. The results showed that:(1) The two precipitation phases were based on a combination of cold cloud processes and warm cloud processes. The accumulated conversion amount and conversion rate of microphysical processes in the warm-area phase were all much larger than those in the cold front phase.(2) 72.6% of rainwater was from the warm-area phase. Rainwater mainly came from the melting of graupel and the melting of snow, while the accretion of cloud water by rain ranked second.(3) The net heating rate with height appeared as an overall warming with two strong heating centers in the lower and middle layers of the troposphere and a minimum heating center around the melting layer. The net heating effect in the warm-area phase was stronger than that in the cold front phase.(4) Warm cloud processes contributed most to latent heat release, and the thermal effect of cold cloud processes on the storm in the cold front phase was enhanced compared to that in the warm-area phase.(5) The melting of graupel and snow contributed most to latent heat absorption, and the effect of the evaporation of rainwater was significantly reduced in the cold front phase.
