Research On Energy Supply Model Of Reactive Energy And Energy Storage Coupling System In Passive Ultra Low Energy Buildings

At present,the research and development of passive ultra-low energy buildings are proceeding rapidly.In addition to the use of common energy,the application of renewable energy in passive ultra-low energy buildings is gradually being implemented.Heat pumps and solar energy are two of the most common renewable energy sources that can be applied in passive ultra-low energy buildings to build composite energy systems.In this paper,in light of these two types of renewable energy combined with phase change energy storage technology,the system energy supply mode of heat pump technology and solar energy combined with phase change energy storage technology was studied.Combining simulations with actual measurements,the advantages of hybrid energy systems over conventional energy systems are discussed.Taking the demonstration center of ultra-low energy consumption of Shenyang Jianzhu University as a platform,DEST energy simulation software was used to calculate the construction load.The model of phase-change energy storage tank was built by ANSYS,and the influence of different conditions,different inlet water flow speeds,and different arrangement modes on the tank heat release was applied to the phase change energy storage tank using CFD simulation software FLUENT.Explore the optimal solution and apply it to the TRNSYS platform.The solar energy system,heat pump system and composite energy system combined with phase change energy storage technology were simulated through the TRNSYS transient simulation platform.The advantages and disadvantages of the energy supply system were analyzed by comparing the COP values of the heat pump system.Ultrasonic flow meter and temperature and humidity self-recording instrument were used to monitor the winter and summer seasons of the ultra-low energy demonstration center of Shenyang Jianzhu University.The accuracy of the simulation was confirmed by the comparison of the measured and simulated values.The energy-saving simulation software eQUEST was used to analyze the energy-saving rate and energy-saving rate of the solar heat pump system combined with the phase-change energy storage technology,and economic parameters were obtained.Through the simulation calculation of the energy simulation software DeST,the maximum heat load of the Shenyang Low-energy Energy Consumption Demonstration Center building in the year is 11.6 KW,and the maximum cooling load in the year is 9.75 KW.Through simulation analysis of FLUENT simulation software,the optimal solution conditions of the phase change storage heat storage tank are as follows:The heat storage phase is performed at a speed of 0.9 m/s,and the water intake flow rate of the water tank during the heat release phase is 0.03 m/s.The diameter of the phase change package unit is 30mm,and the phase change package units are staggered.The phase change thermal storage unit has the best heat storage and heat release properties.Based on the transient simulation software TRNSYS platform,the cold accumulation phenomenon of the heat pump system is obtained.The solar energy system also has different problems with low energy density and large impact on weather conditions.Combined with the composite energy system of phase change energy storage technology,the COP value of the heat pump unit in the system is increased by about 16.67%compared with that of the ordinary heat pump system,reducing the hot and cold accumulation phenomenon,making the heat storage more lasting and the low temperature more stable.Enhance the efficiency of the system.After economic analysis and calculation,the heat pump system using the phase change storage heat storage tank can not only effectively relieve the grid pressure at the peak of power consumption,but also save 27 yuan per square meter of building area during the entire heating season.The actual monitoring data of the ultra-low energy demonstration center of Shenyang Jianzhu University in winter and summer will be compared with the simulation results.It can be concluded that the source and inlet side inlet and outlet temperature deviations are controlled within 15%,and the simulation results are accurate.Through the analysis of the energy simulation software eQUEST,it is estimated that the electricity savings of 57.785 yuan is expected throughout the year,saving 58.01%of the electricity cost.The research results of this paper can play an active role in the research of a hybrid energy system that combines renewable energy sources.