| Electric heating solid energy storage heating technology has been widely used in the implementation of clean heating,with the following advantages: first,balancing the load on the power grid and relieving the pressure on the power system;second,taking advantage of the difference in electricity prices at different times to reduce the cost of heating;third,it is a concrete practice to achieve the goal of "carbon neutrality" in the heating industry.It is a concrete practice to achieve the goal of "carbon neutrality" in the heating industry.However,there are some problems in the engineering application,mainly that the heat accumulator and electric heating wire are damaged after the system has been running for a period of time,which affects the normal heat supply.Analyzing the reasons,it is believed that the uneven distribution of the flow rate of the heat dissipation orifice of the accumulator makes the heat in some positions cannot be fully released,and after several heat storage and discharge cycles,the phenomenon of local "heat accumulation" exists in the accumulator,and the actual temperature exceeds the tolerance temperature causing damage to the equipment.At present,there are four common forms of air supply for electrically heated solid energy storage devices,namely,downward air supply and return,opposite side downward air supply and return,same side downward air supply and return,and bottom air supply and top air return.This study is aimed at the problem of air distribution uniformity in the electric heating solid energy storage heating system.Secondly,the heating project is combined with the design calculation of the thermal storage device,and the energy storage heating test bench is built to conduct cold and hot state tests respectively,and the experimental data are recorded by multiple temperature sensors and wind speed sensors,and the experimental results are compared and analyzed with the simulated data to verify the feasibility of the model.Finally,the model is used to simulate the factors influencing the uniformity of flow rate distribution of the energy storage device and structural optimization simulation.The results of the study show that there is the problem of uneven heat release from different locations in the same section of the heat accumulator,and the uneven airflow distribution is one of the important reasons for the temperature difference and heat accumulation inside the heat accumulator.The modularization of the heat accumulator,independent air bin and independent air supply is beneficial to the operation of the unit.The flow velocity distribution of each heat sink in the windward section of the accumulator is mainly influenced by the air supply structure of the energy storage device and the characteristics of the air inlet,and the change of the air inlet flow velocity has limited effect on the uniform distribution of the flow in each heat sink of the accumulator.On this basis,the flow velocity distribution on the windward side of the heat accumulator was analyzed from three aspects,namely,the width of the air bin,the angle of the air inlet and the addition of a static pressure box at the air outlet.After several simulations,it is found that the uniformity of windward section is basically stable when the width of wind bin is greater than 2.2m,and the uniformity is relatively good when the angle of wind opening is 15°/20°,but it is greatly influenced by the wind opening.After the addition of the static pressure box,the energy storage device not only eliminates the influence of the air outlet,but also increases the average flow velocity distribution uniformity index by 13.6%,the heat storage body cooling hole flow velocity distribution is more uniform,and the device air distribution capacity is optimized. |
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