The Influence Of Different Direct Electrical Heating Devices On Indoor Thermal Environment And Design Calculation

In recent years,with the promotion of a series of clean energy heating policies in China and the rapid development of wind power,there is a huge development space for the direct electrical heating.Although this heating method is convenient to use,environmental protection and flexible control,there are many kinds of electric heating devices on the market at present and users lack the basis for selection in practical application,which leads to the problems of uncomfortable heating rooms and higher heating costs and seriously restricts its further promotion and application.In this paper,three kinds of direct electrical heating devices,which are common electric heater,electric heating plate and solid thermal storage electric heater on the market,are selected as the research object,and the influence of three kinds of electrical heating devices on indoor thermal environment and their design calculation are made a comparative study.First of all,an experimental platform was built to test the indoor temperature field of the ordinary electric heater and the electric heating plate during heating.Through the experiment,it was found that in the case of the same power,the vertical temperature difference of electric heater is about 2.0℃ higher than that of electric heating plate in the experimental room,The horizontal temperature difference of electric heater is about 1.0℃ higher than that of electric heating plate;In the case of the same power,when heating with electric heating plate,the average temperature rise rate in the whole temperature period of the experimental room is higher than that of ordinary electric heater.Next,based on the experimental test and computational fluid dynamics theory,three kinds of three-dimensional mathematical physical models of direct electrical heating room were established,and the temperature field and velocity field of the room were simulated by using Anasys software.The reliability of the model and the correctness of the simulation results were verified by comparing the simulation results with the experimental data.the indoor temperature distribution and the airflow movement characteristics of three direct electrical heating devices are obtained.Evaluate the indoor thermal environment of three kinds of electric heating devices when heating,and the influence on indoor thermal environment was further studied when the electric heating plate was laid in different ways and the solid thermal storage electric heater changed the air supply velocity or the air supply Angle.the results show that the room temperature distribution is the most even when the electric heating plate is used for heating,and the room temperature distribution is the most uneven when the solid thermal storage electric heater is used for heating.When the solid thermal storage electric heater is used for heating,the vertical temperature difference of the room can be as high as 8.0℃ due to the higher air outlet temperature;When the electric heating plate is used for heating under the same power and the same area,the vertical temperature difference in the heating room is the largest when electric heating plates are laid on the ceiling,The next is the electric heating plate is laid on the side wall and the vertical temperature difference in the room is the smallest when electric heating plate is laid on the ground.The larger air supply velocity at the outlet of the solid heat storage electric heater,the larger the vertical temperature difference and horizontal temperature difference in the room.The larger the air supply angle of the solid heat storage electric heater is,the faster the temperature and speed of hot air flow decays after entering the room.At the same heating time the larger the air supply Angle is,the more uniform the indoor temperature distribution is.Finally,using Visual Studio software to develop direct electrical heating design calculation software,the user can enter the heating room parameters in the software for the design and selection calculation of the electric heating device.By comparing the economy of three kinds of direct electrical heating,the following conclusions are drawn: For areas where there is no peak-to-valley price or the single heating time is short,ordinary electric heaters are the most economical,followed by electric heating panels,and solid thermal storage electric heaters are not recommended.For areas with peak-valley electricity price and all-day heating,solid thermal storage electric heaters are the most economical.According to the above comparative study,the author gives some instructional suggestions for choosing three kinds of direct electrical heating devices reasonably.This paper provides theoretical basis for rational selection and application of three kinds of direct electrical heating devices of ordinary electric heater,electric heating plate and solid thermal storage electric heater.