The face velocities of the high efficiency particulate air filters and the ultra low penetration airfilters in fan filter units (FFUs) have large relative standard deviation and turbulivity. It seriously affects the ...The face velocities of the high efficiency particulate air filters and the ultra low penetration airfilters in fan filter units (FFUs) have large relative standard deviation and turbulivity. It seriously affects the unidirectivity of the flow in the unidirectional flow clean zone and cleanroom. The cross contamination in this kind of unidirectional flow area is hardly controlled. It is significant to find optional method for keeping the face velocity uniformity of FFU and reducing the face velocity turbulivity of FFU, furthermore, to keep the cleanliness level under FFUs. The normal and easy method is to add flow rectifiers under filters. FFUs with various flow rectifiers have been tested. The uniformity and turbulivity of facevelocity under the FFU are presented in this paper. The influence of the facevelocity uniformity and turbulivity on the contamination boundary of the unidirectional flow is studiedas well.展开更多
Wind power has made rapid progress and should gain significance as an energy resource,given growing interest in renewable energy and clean energy.Offshore wind energy resources have attracted significant attention,as,...Wind power has made rapid progress and should gain significance as an energy resource,given growing interest in renewable energy and clean energy.Offshore wind energy resources have attracted significant attention,as,compared with land-based wind energy resources,offshore wind energy resources are more promising candidates for development.Sea winds are generally stronger and more reliable and with improvements in technology,the sea has become a hot spot for new designs and installation methods for wind turbines.In the present paper,based on experience building offshore wind farms,recommended foundation styles have been examined.Furthermore,wave effects have been investigated.The split installation and overall installation have been illustrated.Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed.This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.展开更多
The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor an...The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive, as for the upwind type, the inner and the outer rotational armatures, respectively, in keeping the rotational torque counter-balanced between both wind rotors/armatures. The unique rotational behaviors of the tandem wind rotors and the fundamental performances of the unit have been discussed at the previous paper. Continuously, this paper investigates experimentally and numerically the flow condition around the wind rotors to know the flow interactions between the front and the rear wind rotors, and optimizes the blade profile in the front wind rotor. The front blade should work fruitfully at the larger radius and had better not work at the smaller radius for giving plenty of wind energy to the rear wind rotor, taking account of the flow interaction between both wind rotors.展开更多
The authors have invented a superior wind power unit, which is composed of tandem wind rotors and double rotational armature type generator without the traditional stator. This unit is called ＂intelligent wind power ...The authors have invented a superior wind power unit, which is composed of tandem wind rotors and double rotational armature type generator without the traditional stator. This unit is called ＂intelligent wind power unit＂. At upwind type unit, the large-sized front wind rotor and the small-sized rear wind rotor drive the inner and the outer rotational armatures respectively, in keeping the rotational torque counter-balance between both wind rotors/armatures. This paper discusses the acoustic noise emitted from the tandem wind rotors. As for tandem wind rotors, the tip vortex shedding from the front wind rotor may make a loud acoustic noise if the vortex attacks the rear wind rotor. Intelligent wind power unit, however, has no chance to increase the acoustic noise level by the tip vortex because the diameter of the front wind rotor is reasonably larger than the diameter of the rear wind rotor. The vorticity generated in the boundary layer on the blade can be observed obviously at wake flow and can be evaluated quantitatively at flow conditions measured by a hot-wire anemometer at a wind tunnel. The flow conditions have shown that the radial and axial components of vorticities contribute to emit the acoustic noise.展开更多
文摘The face velocities of the high efficiency particulate air filters and the ultra low penetration airfilters in fan filter units (FFUs) have large relative standard deviation and turbulivity. It seriously affects the unidirectivity of the flow in the unidirectional flow clean zone and cleanroom. The cross contamination in this kind of unidirectional flow area is hardly controlled. It is significant to find optional method for keeping the face velocity uniformity of FFU and reducing the face velocity turbulivity of FFU, furthermore, to keep the cleanliness level under FFUs. The normal and easy method is to add flow rectifiers under filters. FFUs with various flow rectifiers have been tested. The uniformity and turbulivity of facevelocity under the FFU are presented in this paper. The influence of the facevelocity uniformity and turbulivity on the contamination boundary of the unidirectional flow is studiedas well.
基金Supported by 111 Project Foundation under Grant No.B07019the National Natural Science Foundation of China under Grand No.50979020
文摘Wind power has made rapid progress and should gain significance as an energy resource,given growing interest in renewable energy and clean energy.Offshore wind energy resources have attracted significant attention,as,compared with land-based wind energy resources,offshore wind energy resources are more promising candidates for development.Sea winds are generally stronger and more reliable and with improvements in technology,the sea has become a hot spot for new designs and installation methods for wind turbines.In the present paper,based on experience building offshore wind farms,recommended foundation styles have been examined.Furthermore,wave effects have been investigated.The split installation and overall installation have been illustrated.Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed.This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.
文摘The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive, as for the upwind type, the inner and the outer rotational armatures, respectively, in keeping the rotational torque counter-balanced between both wind rotors/armatures. The unique rotational behaviors of the tandem wind rotors and the fundamental performances of the unit have been discussed at the previous paper. Continuously, this paper investigates experimentally and numerically the flow condition around the wind rotors to know the flow interactions between the front and the rear wind rotors, and optimizes the blade profile in the front wind rotor. The front blade should work fruitfully at the larger radius and had better not work at the smaller radius for giving plenty of wind energy to the rear wind rotor, taking account of the flow interaction between both wind rotors.
文摘The authors have invented a superior wind power unit, which is composed of tandem wind rotors and double rotational armature type generator without the traditional stator. This unit is called ＂intelligent wind power unit＂. At upwind type unit, the large-sized front wind rotor and the small-sized rear wind rotor drive the inner and the outer rotational armatures respectively, in keeping the rotational torque counter-balance between both wind rotors/armatures. This paper discusses the acoustic noise emitted from the tandem wind rotors. As for tandem wind rotors, the tip vortex shedding from the front wind rotor may make a loud acoustic noise if the vortex attacks the rear wind rotor. Intelligent wind power unit, however, has no chance to increase the acoustic noise level by the tip vortex because the diameter of the front wind rotor is reasonably larger than the diameter of the rear wind rotor. The vorticity generated in the boundary layer on the blade can be observed obviously at wake flow and can be evaluated quantitatively at flow conditions measured by a hot-wire anemometer at a wind tunnel. The flow conditions have shown that the radial and axial components of vorticities contribute to emit the acoustic noise.
