| Industrial enterprises emit a large amount of high-temperature flue gas every year,which not only causes environmental damage,but also causes a huge waste of energy.In addition,some buildings outside the energy supply range of the central heating system mostly use self-built boiler rooms to solve their own heating needs.The primary energy utilization efficiency is generally low,which is not compatible with today’s ecological low-carbon energy-saving practices.The mobile heat storage technology has emerged to solve the problem of using industrial flue gas waste heat in different places.The mobile phase-change heat storage device is the core component of this technology.This article is based on the mobile phase-change heat storage device using industrial flue gas waste heat to conduct technical and application research.First,the paper discusses the selection principles of phase change heat storage materials,aiming at the requirements of industrial flue gas waste heat around 200℃左右and mobile heat storage heating technology,taking phase change temperature,phase change latent heat value,specific heat capacity,stability and economy as The main selection factor is erythritol(add 10%expanded graphite)as the heat storage medium in the mobile phase change heat storage device,which lays the foundation for the improvement of the heat storage capacity of the mobile phase change heat storage device.Secondly,the paper analyzes the heat transfer characteristics of the solid-liquid phase change material,summarizes the mathematical model and solution method of the solid-liquid phase change heat transfer problem,and discusses the type of mobile phase change heat storage device and the structure of each part.The development and application of mobile phase change thermal storage devices provide a theoretical basis.Next,aiming at the characteristics of industrial flue gas at around 200℃左右,the thesis takes the indirect waste heat utilization system as the application object,and carries out the specific design of each part of the mobile phase change heat storage device,and uses the FLUENT numerical simulation software to analyze the mobile phase under different working conditions.The heat storage and release process of the variable heat storage device is simulated,and the charge and release characteristics of the mobile phase change heat storage device are studied.The simulation results show that natural convection has little effect on the heat transfer between the heat storage medium and the heat-carrying medium,and the farther the heat storage medium is from the heat exchange tube,the longer it takes for the heat storage medium to undergo phase change from its initial state;In the length direction of the phase change heat storage device,the temperature distribution and the solid-liquid distribution of the heat storage medium at each time are uniform;the heat release process is more regular than the heat storage process,and the temperature distribution and the solid-liquid distribution of the heat storage medium at each time are more regular And evenly.For the mobile phase change heat storage device designed in the thesis,its single heat storage capacity is 1033.80MJ,the heat storage efficiency is 93.34%,the total heat storage process takes 8.5 hours,and the heat storage power is 31.43k W;the heat carrier working medium in the heat release process The heat gain is 894.09MJ,the heat release efficiency is 95.48%,the total heat release process takes 5 hours,and the heat release power is 47.01k W;the latent heat storage heat release power of the mobile phase change heat storage device is significantly higher than the sensible heat storage heat release power.The comprehensive heat storage and release efficiency is 80.73%.Finally,the paper analyzes the application benefits of the mobile heat storage heating method,and analyzes the maximum transportation distance of the mobile phase change heat storage device engineering application from different angles.From the perspectives of energy-saving benefits,economic benefits,and environmental benefits,the maximum transportation distances of this method are calculated to be 9.8km,18.3km,and 158 km,respectively. |
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