Experimental Study On The Thermal Energy Storage Performance Of Thermocline Single Tank

Peaking of combined heat and power generating(CHP)unit is important to the utilization of renewable energy.With the development of society,the heating demand and the capacity of CHP units are increasing,renewable energy such as wind power and solar power are developing continuously.However,the utilization rate of renewable energy is much lower than the generation capacity.So that CHP units' participating in peak shaving is of great significance.Heat storage technology is a buffer between the producing and using of energy,Low-temperature heat storage materials can be used in the CHP unit,when the heat production is sufficient,we can store it with the thermocline tank,and use it when the unit is short of heat.The heat storage equipment can make the electric heat decoupling to a certain extent and improve the peaking capacity of the CHP unit.In this paper,a thermocline single tank storage experiment is designed,including the design of main equipment,the design of thermal storage system and the selection of the major equipment.The experimental results show that keeping a certain temperature gap can form a stable thermocline in a single tank,which can achieve the purpose of heat storage.Internal heat conduction is larger than the external heat dissipation in the middle section of the tank,the thermocline has the tendency of gradually dissipating.Therefore,heat storage equipment should not be placed for a long time in the practical application.In a certain range of flow rate,the temperature curves are similar to each other,so we can choose the economical one.In a variety of experimental conditions,the storage tank always maintain a stable thermocline,showing a very good thermal storage performance.