基于斜温层等效容积的大型蓄热罐动态特性分析

斜温层蓄热罐可以提高热电联产(Combined heat and power, CHP)机组在供热期间的调峰能力，因此逐渐向大型化发展，但设计参数对蓄热罐的性能影响较大，且采用目前的性能评估方法效率较低。本文建立了大型蓄热罐的物理模型及数学模型，研究了蓄热过程中斜温层的形成及变化过程，提出了斜温层等效容积的概念，同时分析了结构参数及运行参数对斜温层等效容积的影响。结果表明：形成稳定斜温层后，随着蓄热量的增加，斜温层厚度变化不大，采用斜温层等效容积可以更高效的评估蓄热罐的性能。比较不同工况下蓄热罐等效容积的相对变化量可知，不同影响因素对斜温层等效容积的影响从高到低排序依次为布水器布置、蓄热流量、高径比和冷热水温差。研究为大型蓄热罐的性能评估提供了一种新参考。

Dynamic characteristics analysis of large-scale heat storage tank based on equivalent volume of thermocline

The thermocline heat storage tank can improve the peak shaving capacity of the CHP (Combined heat and power) units during the heating period, so it is gradually toward large-scale direction. However, the design parameters have a great impact on the performance of the heat storage tank, and the current performance evaluation methods are inefficient. In this paper, the physical model and mathematical model of a large-scale heat storage tank are established, the formation and change process of the thermocline in the process of heat storage are studied. Then, the concept of the equivalent volume of the thermocline is proposed, and the influence of structural parameters and operating parameters on the equivalent volume of the thermocline is analyzed. The results show that after the formation of a stable thermocline, the thickness of the inclined temperature layer changes little with the increase of the heat storage capacity. Thus, the equivalent volume of the thermocline can be used to evaluate the performance of the heat storage tank more efficiently. Comparing the relative variation of the equivalent volume of the heat storage tank under different working conditions, it can be seen that the influence of different influencing factors on the equivalent volume of the thermocline is ranked from high to low as follows: water distributor arrangement, heat storage flow, height-diameter ratio and temperature difference between cold and hot water. The research provides a new reference for the performance evaluation of large-scale heat storage tanks.