分层-掺混切换式蓄热水箱热特性实验及评价研究

稳定分层、充分掺混是蓄热水箱实现高效供暖和恒温出水2种功能的重要手段。该研究设计一种分层-掺混一体式蓄热水箱,可实现2种功能的有效切换,满足分层高效供暖和恒温生活热水在不同时段、不同季节的灵活需求。搭建一套蓄热水箱热力学特性测试实验系统,利用分层效率、效率等蓄热水箱热性能评价指标,研究不同尺寸、流量、温度下分层-掺混式蓄热水箱的热力学性能及动态响应特征。以125 L的实验蓄热水箱为例,结果表明：在分层模式下,热分层速率、稳定性显著优于常规水箱,效率和分层效率明显提高,效率可达90%以上;在掺混模式下,掺混速度明显提高,分层效率迅速降低到0.10,实现了蓄热水箱的完全混合,结果对分层-掺混双效水箱的开发与应用具有一定指导。

EXPERIMENTAL AND EVALUATION RESEARCH ON THERMAL PERFORMANCE OF STRATIFIED-MIXING SWITCHING HEAT STORAGE WATER TANK

Stable stratification and adequate mixing are important means for the heat storage tank to achieve the two functions of efficient heating and constant temperature water output. This work designed a stratified-mixing integrated heat storage tank, which can realize the effective switching of two functions, and meet the flexible needs of stratified high-efficiency heating and constant temperature domestic hot water in different periods or different seasons. In this study, a set of thermodynamic characteristics test experimental system of the heat storage tank was built, using stratification efficiency, exergy efficiency and other evaluation indicators to study the thermodynamic performance and dynamic response characteristics of the stratified-mixing heat storage tank under different sizes, flow rates and temperatures. Taking a 125 L experimental heat storage tank as an example, the results show that： in the stratification mode, the thermal stratification rate and stability are significantly better than that of the conventional heat storage tank, the exergy efficiency and stratification efficiency are obviously improved, and the exergy efficiency can reach more than 90%. In the mixing mode, the mixing speed is significantly increased, and the stratification efficiency is quickly reduced to 0.10, which realizes the complete mixing of the heat storage tank, which has certain guidance for the development and application of the stratification-mixing double-effect heat storage tank.