A trajectory imaging based method for measuring the velocity and diameter of coal particles was presented.By using an industrial charge-coupled device(CCD)camera and a low power semiconductor laser,the images of coal ...A trajectory imaging based method for measuring the velocity and diameter of coal particles was presented.By using an industrial charge-coupled device(CCD)camera and a low power semiconductor laser,the images of coal particles under relatively long exposure time were recorded and then processed to yield both the velocities and sizes.Fundamental research on this method with special attention to recording parameters,e.g.,magnification factor and exposure time,was carried out.For most of the test cases,the results agree with those obtained by particle image velocimetry(PIV)and shadow imaging method.Measurements with good accuracy can be obtained when the imaging magnification factor and exposure time are set appropriately,making N be larger than 3.5,and R between 5-7,where N and R are the number of pixels occupied by the average width and the ratio of length to width of particle trajectory on the image,respectively.The work indicates the feasibility and potential application of the present measurement method for online measurement of coal powder in pipes in industrial power plants.展开更多
Molten salt is often used for heat transfer and thermal energy storage in concentrated solar power.Molten salt leakage and migration is a significant issue in its application.Molten salt migration and solidification i...Molten salt is often used for heat transfer and thermal energy storage in concentrated solar power.Molten salt leakage and migration is a significant issue in its application.Molten salt migration and solidification in thermal porous foundation materials through cracks are experimentally investigated.The impact of factors,including crack length and width,operation temperature,and leakage mass of molten salt,are studied through an experimental device modeling the leakage of the actual molten salt storage tank.Experimental results show that the crack width and length slightly affect the migration depth,but directly affect the shape of the agglomeration of solidified salt and porous foundation material.The most important factor affecting the migration depth of molten salt leaking through cracks is the tank operating temperature.The molten salt migration depth when the operating temperature is 500℃ is 95.8% higher than that with an operating temperature of 300℃.As the leakage molten salt mass reached 400 g,the average migration width increased by 23.6%,but the migration depth only increased by 5.2%.It is found that the foundation material temperatures after leakage accidents increase with an increase in the mass of leaked molten salt.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 51176162 and 51276164)the National Basic Research Program (973) of China (No. 2009CB219802)+2 种基金the Zhejiang Provincial Science and Technology Project (No. 2012C21077)the Zhejiang Provincial Natural Science Foundation of China (No. Y1110642)the Program of Introducing Talents of Discipline to University (No. B08026),China
文摘A trajectory imaging based method for measuring the velocity and diameter of coal particles was presented.By using an industrial charge-coupled device(CCD)camera and a low power semiconductor laser,the images of coal particles under relatively long exposure time were recorded and then processed to yield both the velocities and sizes.Fundamental research on this method with special attention to recording parameters,e.g.,magnification factor and exposure time,was carried out.For most of the test cases,the results agree with those obtained by particle image velocimetry(PIV)and shadow imaging method.Measurements with good accuracy can be obtained when the imaging magnification factor and exposure time are set appropriately,making N be larger than 3.5,and R between 5-7,where N and R are the number of pixels occupied by the average width and the ratio of length to width of particle trajectory on the image,respectively.The work indicates the feasibility and potential application of the present measurement method for online measurement of coal powder in pipes in industrial power plants.
基金supported by the National Natural Science Foundation of China(No.51366010)the Inner Mongolia Autonomous Region Open Major Basic Research Project(No.20120905),China
基金Project supported by the National Natural Science Foundation of China(No.52036008)。
文摘Molten salt is often used for heat transfer and thermal energy storage in concentrated solar power.Molten salt leakage and migration is a significant issue in its application.Molten salt migration and solidification in thermal porous foundation materials through cracks are experimentally investigated.The impact of factors,including crack length and width,operation temperature,and leakage mass of molten salt,are studied through an experimental device modeling the leakage of the actual molten salt storage tank.Experimental results show that the crack width and length slightly affect the migration depth,but directly affect the shape of the agglomeration of solidified salt and porous foundation material.The most important factor affecting the migration depth of molten salt leaking through cracks is the tank operating temperature.The molten salt migration depth when the operating temperature is 500℃ is 95.8% higher than that with an operating temperature of 300℃.As the leakage molten salt mass reached 400 g,the average migration width increased by 23.6%,but the migration depth only increased by 5.2%.It is found that the foundation material temperatures after leakage accidents increase with an increase in the mass of leaked molten salt.
