Based on the temperature situation during the rolling process of 4200 mm/3500 mm medium and thick plates at Baosteel,this article analyzes the influencing factors of temperature changes during the rolling process from...Based on the temperature situation during the rolling process of 4200 mm/3500 mm medium and thick plates at Baosteel,this article analyzes the influencing factors of temperature changes during the rolling process from the perspective of heat transfer theory and the temperature change law during the rolling process.The temperature loss during the four rolling processes is tracked on site,and the temperature drop model parameters during the rolling process of 4200mm/3500mm medium and thick plates at Baosteel are quantitatively provided.It is applied to actual rolling production and has achieved good results.展开更多
With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperatur...With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.展开更多
We investigated seasonal dynamics of phenolics substance in leaf and bark of two cultivars of poplar, Populus alba×berolinensis and P. בZhonglin Sanbei 1’, during autumn temperature drop for analyzing the...We investigated seasonal dynamics of phenolics substance in leaf and bark of two cultivars of poplar, Populus alba×berolinensis and P. בZhonglin Sanbei 1’, during autumn temperature drop for analyzing the roles of phenolic secondary metabolites in cold resistance. Results show that the contents of condensed tannin and flavonoid in poplar leaf and the flavonoid contents in bark of P. בZhonglin Sanbei 1’ were increased with the decrease of autumn minimum temperature, showing a significantly negative correlation between the contents of soluble phenolic substance in the leaves and changeable temperature. In contrast, lignin content in the poplar leaves is decreased in the process of temperature drop, showing a significantly positive correlation. These results indicate that the variation in phenolic substance has a close correlation with its cold-resistance during the autumn temperature drop.展开更多
Temperature evolution of a working piece during hot rolling has a significant influence on the microstmcture and final mechanical properties of the material. As the measurement technologies improve, on-line measuremen...Temperature evolution of a working piece during hot rolling has a significant influence on the microstmcture and final mechanical properties of the material. As the measurement technologies improve, on-line measurement of the temperature across the strip width has become accessible, and thus monitoring and control of the transversal temperature distribution during hot rolling can be realized. The scanning of the temperature across the strip width can help us to understand the state of the temperature variation at the strip edges and as a result help us improve the temperature homogeneity of the strip. In this paper, reaearch on temperature distribution along the strip width is reviewed first, and then the mechanism of the scanning measuring devices is introduced. With the temperature scanning measurement data taken from the finishing mill entry point and the down coiler entry point, the temperature distribution at the strip edges is analyzed. It is pointed out that the roughing process is the main contributor to the temperature inhomogeneity. Furthermore,the contribution of the edger heater to the temperature homogeneity is investigated.展开更多
The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side w...The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side walls and free surface of the channel have been taken from the literature. For each geometry, the volumetric flow rate, mean residence time and temperature drop as a function of the channel inclination angle were determined. The rectangular and trapezoidal geometries present the smallest temperature drops, while the triangular geometry presents the greatest temperature drop. The factors that most affect this drop are the value of the free surface area of the channel, and the average residence time of the molten metal in the channel.展开更多
High pressure pipeline transportation has been an established technology for economically transporting large amounts of CO_(2).However,there are still issues and associated risks that have to be effectively addressed ...High pressure pipeline transportation has been an established technology for economically transporting large amounts of CO_(2).However,there are still issues and associated risks that have to be effectively addressed and adequately understood.It is well known that a strong JouleThomson Cooling effect can occur when pressurized CO_(2) flows through a choke valve.Thus,to investigate the choking characteristics especially the temperature drop of high pressure CO_(2),a new laboratory scale experimental setup(total length of 14.85 m and the inner diameter of 15 mm)was constructed.Steady choked flow and transient choked flow tests were carried out respectively for pressurized CO_(2) in various initial phases.The phase transitions and temperature drop characteristics were then studied following the choked flow and the results show that the phase transitions in steady choked flow differs significantly from that in transient choked flow.For transient choked flow of various initial phases,all the flows downstream would transfer from single phase to gas-liquid twophase flow.Furthermore,the effect of water on transient choked flow of supercritical CO_(2) pipeline was investigated,and the phenomena of solid particles deposition was captured which was paramount importance of ensuring the safety operation of CO_(2)pipelines when throttling by the choke valves.展开更多
Based on principles of vapor coagulation, a method of extracting fresh water from the atmosphere was put forward. Its principles are simple, and it is easy to make and install the equipment made cheaply. Moreover, the...Based on principles of vapor coagulation, a method of extracting fresh water from the atmosphere was put forward. Its principles are simple, and it is easy to make and install the equipment made cheaply. Moreover, there is no or much less energy consumed during the extraction process, so there is no environmental pollution. In a word, this method of extracting fresh water from the atmosphere is of great practical value.展开更多
A computational model of thermal behavior of the top-surface slag layers in continuous casting mold was applied to interpret the thermal insulation of mold powder. The temperature drop of liquid steel caused by heat r...A computational model of thermal behavior of the top-surface slag layers in continuous casting mold was applied to interpret the thermal insulation of mold powder. The temperature drop of liquid steel caused by heat re moral at the interface of molten steel and slag in mold was proposed to evaluate the thermal insulation of mold slag. The calculation results show that slag consumption is one of important factor influencing the temperature drop, while the casting speed has no obvious effect on it. With the increase of slag consumption, the temperature drop is increased.展开更多
文摘Based on the temperature situation during the rolling process of 4200 mm/3500 mm medium and thick plates at Baosteel,this article analyzes the influencing factors of temperature changes during the rolling process from the perspective of heat transfer theory and the temperature change law during the rolling process.The temperature loss during the four rolling processes is tracked on site,and the temperature drop model parameters during the rolling process of 4200mm/3500mm medium and thick plates at Baosteel are quantitatively provided.It is applied to actual rolling production and has achieved good results.
基金supported by the National Natural Science Foundation of China(52104064)(52074089)the China Postdoctoral Science Foundation(2020M681074)+3 种基金Heilongjiang Provincial Natural Science Foundation of China(YQ2023E006)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2020152)Postdoctoral Science Foundation of Heilongjiang Province in China(LBH-TZ2106)(LBH-Z20122)Northeast Petroleum University Talents Introduction Fund(2019KQ18).
文摘With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.
基金supported by Special Fund of Forestry Industrial Research for Public Welfare of China(201004040)Scientific and Technological Project in Heilongjiang Province(GA09B202-02)
文摘We investigated seasonal dynamics of phenolics substance in leaf and bark of two cultivars of poplar, Populus alba×berolinensis and P. בZhonglin Sanbei 1’, during autumn temperature drop for analyzing the roles of phenolic secondary metabolites in cold resistance. Results show that the contents of condensed tannin and flavonoid in poplar leaf and the flavonoid contents in bark of P. בZhonglin Sanbei 1’ were increased with the decrease of autumn minimum temperature, showing a significantly negative correlation between the contents of soluble phenolic substance in the leaves and changeable temperature. In contrast, lignin content in the poplar leaves is decreased in the process of temperature drop, showing a significantly positive correlation. These results indicate that the variation in phenolic substance has a close correlation with its cold-resistance during the autumn temperature drop.
文摘Temperature evolution of a working piece during hot rolling has a significant influence on the microstmcture and final mechanical properties of the material. As the measurement technologies improve, on-line measurement of the temperature across the strip width has become accessible, and thus monitoring and control of the transversal temperature distribution during hot rolling can be realized. The scanning of the temperature across the strip width can help us to understand the state of the temperature variation at the strip edges and as a result help us improve the temperature homogeneity of the strip. In this paper, reaearch on temperature distribution along the strip width is reviewed first, and then the mechanism of the scanning measuring devices is introduced. With the temperature scanning measurement data taken from the finishing mill entry point and the down coiler entry point, the temperature distribution at the strip edges is analyzed. It is pointed out that the roughing process is the main contributor to the temperature inhomogeneity. Furthermore,the contribution of the edger heater to the temperature homogeneity is investigated.
文摘The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side walls and free surface of the channel have been taken from the literature. For each geometry, the volumetric flow rate, mean residence time and temperature drop as a function of the channel inclination angle were determined. The rectangular and trapezoidal geometries present the smallest temperature drops, while the triangular geometry presents the greatest temperature drop. The factors that most affect this drop are the value of the free surface area of the channel, and the average residence time of the molten metal in the channel.
基金Key laboratory of oil&gas storage&transportation PetroChina(GDGS-KJZX-2016-JS-379)supported by the National Science and Technology Special Project(2016ZX05016-002).
文摘High pressure pipeline transportation has been an established technology for economically transporting large amounts of CO_(2).However,there are still issues and associated risks that have to be effectively addressed and adequately understood.It is well known that a strong JouleThomson Cooling effect can occur when pressurized CO_(2) flows through a choke valve.Thus,to investigate the choking characteristics especially the temperature drop of high pressure CO_(2),a new laboratory scale experimental setup(total length of 14.85 m and the inner diameter of 15 mm)was constructed.Steady choked flow and transient choked flow tests were carried out respectively for pressurized CO_(2) in various initial phases.The phase transitions and temperature drop characteristics were then studied following the choked flow and the results show that the phase transitions in steady choked flow differs significantly from that in transient choked flow.For transient choked flow of various initial phases,all the flows downstream would transfer from single phase to gas-liquid twophase flow.Furthermore,the effect of water on transient choked flow of supercritical CO_(2) pipeline was investigated,and the phenomena of solid particles deposition was captured which was paramount importance of ensuring the safety operation of CO_(2)pipelines when throttling by the choke valves.
基金Supported by the National Natural Science Foundation of China(41006070)Educational Commission of Guangdong Province,China(2012KJCX0065)
文摘Based on principles of vapor coagulation, a method of extracting fresh water from the atmosphere was put forward. Its principles are simple, and it is easy to make and install the equipment made cheaply. Moreover, there is no or much less energy consumed during the extraction process, so there is no environmental pollution. In a word, this method of extracting fresh water from the atmosphere is of great practical value.
文摘A computational model of thermal behavior of the top-surface slag layers in continuous casting mold was applied to interpret the thermal insulation of mold powder. The temperature drop of liquid steel caused by heat re moral at the interface of molten steel and slag in mold was proposed to evaluate the thermal insulation of mold slag. The calculation results show that slag consumption is one of important factor influencing the temperature drop, while the casting speed has no obvious effect on it. With the increase of slag consumption, the temperature drop is increased.