熔盐罐温降计算模型的研究OA

The molten salt tank is an important component of the molten salt energy storage system,and its insulation performance directly affects the operating efficiency and energy consumption of the system.This paper takes the molten salt tank in a CSP project as an example,establishes a temperature drop calculation model for the molten salt tank,studies the main factors affecting the heat loss and 24 h temperature drop of the molten salt tank,and proposes optimization measures for the insulation effect of the molten salt tank.The research results show that:1)Molten salt temperature,molten salt tank diameter,molten salt liquid level,and insulation layer thickness have a significant impact on 24 h temperature drop of molten solt tank,while environmental temperature and environmental convective heat transfer coefficient have a relatively small impact on 24 h temperature drop.The temperature of the molten salt increased from 290℃to 565℃,and the 24 h temperature drop of the molten salt tank increased by 0.52℃,an increase of about 113%.The diameter of the molten salt tank increased from 30 m to 45 m,and the 24 h temperature drop decreased by about 17%.When the molten salt liquid level increased from 7 m to 13 m,the 24 h temperature drop decreased by about 46%.The thickness of the insulation layer increased from 0.4 m to 0.7 m,24 h temperature drop of the molten salt tank decreased by about 35%.The 24 h temperature drop of the molten salt tank is not significantly different under the two operating conditions of annual maximum environmental temperature and annual environmental minimum temperature,with differences of 0.1℃,respectively.When the environmental convective heat transfer coefficient increases from 5 W/(m2·K)to 20 W/(m2·K),the 24 h temperature drop of the molten salt tank only increases by 0.02℃,indicating that its impact on the 24 h temperature drop of the molten salt tank is relatively small.2)Due to the analysis of different influencing factors,the unit time heat loss of the side wall and top of the molten salt tank accounts for a relatively large proportion of the total heat loss,about 73.6%～82.8%.For specific projects,the diameter,molten salt level,molten salt temperature,and ambient temperature of the molten salt tank are all given values.Therefore,when designing the insulation of the molten salt tank,increasing the insulation layer thickness is an effective measure to reduce heat loss and 24 h temperature drop of malten salt tank.