Design And Experimental Researches On Wind Turbine Heating Device With Vertical Axis Spiral Agitation

Under the background of global warming and increasingly severe environmental pollution,accelerating the development of new energy has become the general trend.Wind e nergy,as a clean,pollution-free and green energy with sufficient reserves,has been widely developed and utilized.Vertical axis spiral stirring wind heating is a clean energy and efficient utilization technology that directly converts wind energy into heat energy.This technology directly converts wind energy into heat energy without electric energy conversion,Compared with the conventional form of wind energy heat utilization,it has the advantages of high conversion efficiency,simple structure and unique design.The application of this technology can effectively solve the problem of heating in remote areas and the problem of supplementary temperature in Greenhouse in winter,and effectively alleviate the phenomenon of wind abandonment.Therefore,the research on the stirring heating caused by wind turbine has important application value.In this paper,the vertical axis spiral stirring heating is studied by the combination of stirring heating test and numerical simulation,in order to explore the performance of spiral stirring heating system and lay a theoretical and experimental foundation for the application of this technology in the field of wind turbine heating.This paper has carried out the following research:(1)A stirring heating device is proposed and designed,which includes main and auxiliary helical auger blades,choke blades,mixing tank,frequency modulator,electrical parameter measuring instrument,laser tachometer and so on.The design purpose of the spiral auger blade is to make the thermal medium flow along the radial and axial direction.The main and auxiliary spiral auger blades make the working medium flow in the up and down circulation vortex with the opposite rotation direction through the mixing system composed of gear transm ission.The flow blocking blade prevents the working medium from rotating in the process of high-speed rotation.The violently moving working medium will collide with the auger blade,the choke blade and the inner wall of the mixing tank.At the same time,a large number of irregular friction will occur between the molecules of the working medium,so as to realize the conversion from kinetic energy to internal energy and achieve the purpose of heating.(2)Using the method of stirring heating test,the heating effect of thermogenic substance at different speeds is explored.The test results show that the fastest temperature rise rate is that No.46 hydraulic oil reaches 12.35 ℃ / h at 500 r / min;The fastest increase in heat is saturated sodium chloride solution,reaching 1133.02kj/h;The highest heating efficiency is No.46 hydraulic oil,which reaches 44.29% at 500 r / min.Considering comprehensively,the effect of the stirring heating device is the best when No.46 hydraulic oil is used under the condition of 500 r / min.(3)Computational fluid dynamics(CFD)numerical simulation is used to study the effects of auger blade,working medium type and rotating speed on the flow field in the heating process of spiral stirring.The results show that the flow field around the auger blade is regularly distributed in the radial and axial directions.From the axial flow field distribution,it can be seen that the flow effect of up and down circulation is more obvious with the increase of stirring speed,and a velocity gradient will be formed from inside to outside in the process of circulating flow;From the radial flow field distribution,it can be seen that the S-shaped outer contour of the auger blade will form an obvious velocity gradient,and the thermal mass vel ocity caused by radiation outward along the radial direction of the auger blade shows a decreasing trend.The appearance of circulating vortex and S-shaped high-speed zone and the velocity gradient formed by them from inside to outside will enrich the flow state of working medium and make the velocity distribution more complex,thus increasing the friction opportunities between working medium and working medium and between working medium and device,making the speed of kinetic energy conversion to internal energy faster and achieving the goal of efficient stirring and heating.This study can provide a reference for the study of wind-induced heat of vertical axis spiral stirring.