A renovation project of miniaturization and high efficiency is provided for the hot blast stove .The experimental data tested feasibility of the new-type swirl flow hot blast stove. The normal and hot state experiment...A renovation project of miniaturization and high efficiency is provided for the hot blast stove .The experimental data tested feasibility of the new-type swirl flow hot blast stove. The normal and hot state experiments have been done through changing the angle of gas entering into the regenerator. Factors influencing pressure drop have been studied and analyzed. The experimental results can be formulated in the form of the Ergun equation. The regression equation is obtained. And two modified coefficients are offered to the regenerator pressure drop of the new-type swirl flow hot blast stove.展开更多
Hardness of the TiB2/7075 composite increased with increasing deformation temperature. In the annealed TiB2/7075 composite, a great amount of fiber-like MgZn2 phases (about 1 mum in length) and small MgZn2 phases (abo...Hardness of the TiB2/7075 composite increased with increasing deformation temperature. In the annealed TiB2/7075 composite, a great amount of fiber-like MgZn2 phases (about 1 mum in length) and small MgZn2 phases (about 100 nm in size) were precipitated nearby the grain boundaries where the TiB2 particles exist. After deformation at 300 degreesC, some of the large precipitates and all the small precipitates in these area dissolved into the matrix, meanwhile, fine precipitates were formed in grains. After deformation at 450 degreesC, all the precipitates in the annealed composite dissolved into the matrix, and new phases were precipitated in grains. The dissolution of the large fiber-like precipitate makes the saturation level of the matrix increased and leads to an increased solution hardening and natural aging, which contribute much to the hardening effect.展开更多
TiAl/Ti2AlC composites were prepared by in-situ hot pressing of TilAl/C powders mixtures and sintered at different temperatures were investigated by X- ray diffraction （ XRD ） of samples. The reaction procedure of T...TiAl/Ti2AlC composites were prepared by in-situ hot pressing of TilAl/C powders mixtures and sintered at different temperatures were investigated by X- ray diffraction （ XRD ） of samples. The reaction procedure of Ti-Al-C system could be divided into three stnges. Below 900℃ , Ti reacts with Al to form TiAl intermetallics ; above 900 ℃ , C reacts with remain Ti to form TiC triggered by the exothermal reaction of Ti and Al ; TiAl reacts with TiC to produce dense TiAl/Ti2AlC compasites.In the holding stage, ternary Ti2AlC develops to layered polycrystal and composites pyknosis in the meanwhile. The mechanism of synthesis and microstructure was especially discussed.展开更多
再生器是溶液除湿系统中的关键部件之一,提高再生器综合性能是解决极端热湿气候区高湿问题的有效手段。将指标相关法(CRITIC,Criteria Importance Through Intercriteria Correlation)和优劣解距离法(TOPSIS,Technique for Order Prefer...再生器是溶液除湿系统中的关键部件之一,提高再生器综合性能是解决极端热湿气候区高湿问题的有效手段。将指标相关法(CRITIC,Criteria Importance Through Intercriteria Correlation)和优劣解距离法(TOPSIS,Technique for Order Preference by Similarity to Ideal Solution)联合,建立CRITIC-TOPSIS模型,用于再生器运行入口参数(空气质量流量、溶液质量流量、温度)的选择评价。以永暑岛礁地区为例,通过再生器处理模型得到基础数据以及4个指标的评价体系,采用CRITIC法求得权重后使用TOPSIS法对220种运行入口参数的组合方案进行评价得到最优解。结果表明,空气质量流量为0.1 kg/s、溶液质量流量为0.3 kg/s、溶液温度为56℃时得分0.885,为永暑地区再生器综合性能最优解;再生量指标的权重为0.4,可作为永暑地区再生器综合性能的代表性指标。展开更多
Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from ...Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from coal gasifier gas to very low levels. In this paper, zinc ferrites prepared by co-precipitation were identified as a novel coal gas desulfurization sorbent at high temperature. Preparation of zinc ferrite and effects of binders on pore volume, strength and desulfurization efficiency of zinc ferrite desulfurizer were studied. Moreover, the behavior of zinc ferrite sorbent during desulfurization and regeneration under the temperature range of 350-400 ℃ are investigated. Effects of binders on the pore volume, mechanical strength and desulfurization efficiency of zinc ferrite sorbents indicated that the addition of kaolinite to zinc ferrite desulfurizer seems to be superior to other binders under the experimental conditions.展开更多
The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation...The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided.展开更多
文摘A renovation project of miniaturization and high efficiency is provided for the hot blast stove .The experimental data tested feasibility of the new-type swirl flow hot blast stove. The normal and hot state experiments have been done through changing the angle of gas entering into the regenerator. Factors influencing pressure drop have been studied and analyzed. The experimental results can be formulated in the form of the Ergun equation. The regression equation is obtained. And two modified coefficients are offered to the regenerator pressure drop of the new-type swirl flow hot blast stove.
基金This work was supported by Alexander von Humboldt Foundation of Germany and the National Natural Science Foundation of China under the grant number of
文摘Hardness of the TiB2/7075 composite increased with increasing deformation temperature. In the annealed TiB2/7075 composite, a great amount of fiber-like MgZn2 phases (about 1 mum in length) and small MgZn2 phases (about 100 nm in size) were precipitated nearby the grain boundaries where the TiB2 particles exist. After deformation at 300 degreesC, some of the large precipitates and all the small precipitates in these area dissolved into the matrix, meanwhile, fine precipitates were formed in grains. After deformation at 450 degreesC, all the precipitates in the annealed composite dissolved into the matrix, and new phases were precipitated in grains. The dissolution of the large fiber-like precipitate makes the saturation level of the matrix increased and leads to an increased solution hardening and natural aging, which contribute much to the hardening effect.
文摘TiAl/Ti2AlC composites were prepared by in-situ hot pressing of TilAl/C powders mixtures and sintered at different temperatures were investigated by X- ray diffraction （ XRD ） of samples. The reaction procedure of Ti-Al-C system could be divided into three stnges. Below 900℃ , Ti reacts with Al to form TiAl intermetallics ; above 900 ℃ , C reacts with remain Ti to form TiC triggered by the exothermal reaction of Ti and Al ; TiAl reacts with TiC to produce dense TiAl/Ti2AlC compasites.In the holding stage, ternary Ti2AlC develops to layered polycrystal and composites pyknosis in the meanwhile. The mechanism of synthesis and microstructure was especially discussed.
文摘再生器是溶液除湿系统中的关键部件之一,提高再生器综合性能是解决极端热湿气候区高湿问题的有效手段。将指标相关法(CRITIC,Criteria Importance Through Intercriteria Correlation)和优劣解距离法(TOPSIS,Technique for Order Preference by Similarity to Ideal Solution)联合,建立CRITIC-TOPSIS模型,用于再生器运行入口参数(空气质量流量、溶液质量流量、温度)的选择评价。以永暑岛礁地区为例,通过再生器处理模型得到基础数据以及4个指标的评价体系,采用CRITIC法求得权重后使用TOPSIS法对220种运行入口参数的组合方案进行评价得到最优解。结果表明,空气质量流量为0.1 kg/s、溶液质量流量为0.3 kg/s、溶液温度为56℃时得分0.885,为永暑地区再生器综合性能最优解;再生量指标的权重为0.4,可作为永暑地区再生器综合性能的代表性指标。
基金the Ministry of Science and Technology of China under the Grant No. G2005CB221203the Natural Science Foundation of China under Contract No. 20576087.
文摘Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from coal gasifier gas to very low levels. In this paper, zinc ferrites prepared by co-precipitation were identified as a novel coal gas desulfurization sorbent at high temperature. Preparation of zinc ferrite and effects of binders on pore volume, strength and desulfurization efficiency of zinc ferrite desulfurizer were studied. Moreover, the behavior of zinc ferrite sorbent during desulfurization and regeneration under the temperature range of 350-400 ℃ are investigated. Effects of binders on the pore volume, mechanical strength and desulfurization efficiency of zinc ferrite sorbents indicated that the addition of kaolinite to zinc ferrite desulfurizer seems to be superior to other binders under the experimental conditions.
基金the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2018-ZX04044001-008)the National Natural Science Foundation of China(No.52075328).
文摘The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided.
