【作者】 黄斌；

【导师】 韩吉田；

【作者基本信息】 山东大学 ， 动力工程（专业学位）， 2018， 硕士

【摘要】 太阳能因其具有可持续性、绿色环保等特点,被认为是解决能源问题的重要途径。但是太阳能在利用上具有时间分布不均匀的局限性,太阳能蓄热技术就是针对这一问题展开研究的。除了能源问题,现今人们对居住环境要求较高,在房价日益增长的大背景下,如何利用有限的居住空间也是一个十分重要的研究方向。本文结合这两个问题,设计出一种快速式壁挂自然循环相变太阳能蓄热装置,该装置可悬挂或镶嵌在室外墙壁或阳台上,不需要与集热器有高差,并能快速得到生活所需热水。对快速式壁挂自然循环相变太阳能蓄热装置的研究,本文先是通过查阅文献寻找一种适合本文要求的蓄热材料;然后提出了一种可行的蓄热装置结构;对蓄热结构的自然循环阻力进行计算;最后通过Flunet软件模拟计算了蓄、放热过程,验证了该装置的可行性。通过研究,得到了以下方法与结论:1.提出了一种新的蓄热装置结构,该结构箱体扁平,可悬挂或镶嵌于室外墙壁阳台;利用太阳能集热器与蓄热装置温差,可通过自然循环完成蓄热;直接连接市政管网,也可以达到快速热水的放热效果;并最终确定了一种可供四人淋浴用热水此结构的相变蓄热箱尺寸。2.结合板式太阳能热水系统与供热系统自然循环的工程计算方法,得到一种适合本文蓄热装置自然循环阻力的计算方法,能对该结构及类似结构自然循环蓄热箱的循环阻力计算起到参考作用,并对本设计工况进行了阻力计算。3.通过对设计流速及其附近的不同流速的蓄热过程进行模拟计算,发现在设计流速及附近流速下,蓄热过程均可以在设计时间(3.8h)内完成。根据不同流速的蓄热过程的出水温度,计算得到循环压力,均大于蓄热装置的阻力损失,蓄热装置可以进行自然循环。4.对本设计方案中不同管径的蛇形管放热结构进行模拟计算,发现对于同一直径管道,换热效果会随着流量升高而差。对于同一流量,并不是某一管径换热效果一直最好,当流量在100-200kg/h时,管径较大的换热效果较好,当流量高于200kg/h时,管径较小的换热效果更好。5.对横管放热结构进行模拟计算,发现该结构更适合本设计方案,并确定了该工况下管径、管长、管束数量等参数。更多还原

【Abstract】 Solar energy is considered as an important way to solve energy problems because of its characteristics of sustainability,and environmental protection.However,the use of solar energy has the limitation of non-uniform time distribution.Solar thermal storage technology is to study this issue.In addition to energy issues,people nowadays have a higher demand for living environment.Under the background of increasing house prices,how to use limited living space is also a very important research direction.This paper combines these two problems and designs a fast wall-mounted natural circulation phase-change solar thermal storage device.The device can be suspended or inlaid on an outdoor wall or balcony.It does not need to have a height difference with the collector to complete the natural circulation,and can quickly get the hot water needed for life.For the research of wall-mounted natural cycle phase-change instantaneous water solar thermal storage device,this paper seeks a suitable thermal storage material for the requirements of this paper by consulting the literature.Then it proposes a feasible thermal storage device structure.Then it calculates the natural circulation resistance of the heat storage structure.Finally,the heat storage and heat release process was simulated by Flunet software,and the feasibility of the device was verified.The following methods and conclusions have been obtained:1.A new structure of a heat storage device is proposed,which is flat and can be suspended or inlaid on an outdoor wall balcony.Besides,this device can achieve natural circulation by utilizing the temperature difference between the solar collector and the thermal storage device.Directly connecting to the municipal pipe network,it can also achieve rapid heat release.Finally,the size of a phase change thermal storage tank for a four-person shower with hot water is determined.2.Combining the engineering calculation method for the natural circulation of the plate solar hot water system and the heating system,a calculation method suitable for the natural circulation resistance of the thermal storage device is obtained,which can be used to calculate the circulation resistance of the natural circulation thermal storage tank of this structure and similar structures.Besides,resistance calculations for this design condition have been conducted.3.Through the simulation and calculation of the heat storage process at the designed flow rate and other different flow rate in the vicinity of which,it was found that the heat storage process can be completed within the design time under the design flow rate and the nearby flow velocity.The circulation pressure is calculated according to different water temperature of the heat storage process at different flow rates,which is greater than the resistance loss of the heat storage device.Thus,the heat storage device can perform natural circulation.4.Based on the simulation and calculations of the snake tube exothermic structure with different pipe diameters in this design scheme,it is found that the heat transfer will weaken as the flow rate increases for the same diameter pipe.For the same flow,it is not always the best heat transfer effect for a given diameter.When the flow rate is from 100 to 200kg/h,the heat exchange of the larger pipe diameter is better.When the flow rate is higher than 200kg/h,the heat transfer effect of the smaller pipe diameter is better.5.The exothermic structure of cross pipe was simulated and it was found that the structure is more suitable for the design.The parameters such as pipe diameter,pipe length,and tube bundle number under this working condition were determined.更多还原