Thermodynamic Design Of Key Equipment Of Energy Storage Type Industrial Steam Boiler

Solid heat storage technology,as one of the energy storage technologies of energy storage industrial steam boiler,can convert the off-peak electric energy into heat energy storage,and generate electricity or heat for users through fluid heat transfer into steam during the peak period of electricity consumption.It is found that the low thermal conductivity of the heat storage material will cause the uneven distribution of the overall temperature of the heat storage body.In the process of heat storage,the heat accumulation will lead to the melting of the resistance wire,resulting in safety risks.In the process of heat release,the heat dissipation of the heat storage body will be uneven and the heat transfer efficiency will be reduced.Based on the method of numerical analysis,this thesis takes the solid electrical energy storage device as the main research object.Combined with the actual project data,based on the thermodynamic calculation,the design and calculation of the regenerator parameters are carried out.Taking cast iron as heat storage material,the heat storage and release process of the Regenerator model was simulated and analyzed by ANSYS.The effects of convective heat transfer coefficient and thermal conductivity of thermal insulation material on thermal storage temperature difference were studied.In this thesis,a new method is proposed to obtain the best packing parameter of single grain size by steady-state spherical method.The main research shows:(1)The effects of thermal conductivity,specific heat capacity and Coefficient of thermal expansion on the heat storage and discharge process were analyzed from the perspective of thermal properties.Based on the numerical simulation,it is concluded that the thermal conductivity is the key factor that affects the temperature distribution uniformity of the solid electrical energy storage device during the process of heat storage and discharge.(2)Based on the thermal calculation,the thermal parameters of the regenerator are designed,and the process of heat storage and discharge is simulated and analyzed by ANSYS.The results show that the overall temperature distribution is uniform and the maximum temperature difference is kept at 151 ℃during the heat storage process,while the temperature of the regenerator is consistent with the temperature of the outlet air during the heat release process,and the temperature of the regenerator decreases to 400 ℃,the outlet air temperature reaches 360 ℃,which is higher than the theoretical value of 350 ℃,and the convective heat transfer is greater than the heat released by the regenerator at the lowest temperature of the regenerator.(3)By using Fluent simulation,the effects of thermal conductivity and convective heat transfer coefficient on thermal storage temperature difference under four different operating conditions were analyzed.The results show that under the same thermal storage conditions,the increase of thermal conductivity of thermal insulation material will reduce the overall maximum temperature of the regenerator model,and the increase of convective heat transfer coefficient will lead to the inconsistent overall heating rate,increase the temperature difference of the regenerator model.(4)The steady-state sphere method was used to measure the variation of thermal conductivity of accumulated quartz sand particles with temperature under different particle sizes.It is concluded that in the range of 20-110℃,the diameter of quartz sand particles with the highest thermal conductivity is 60-80 mesh,which is the best single particle size accumulation parameter.