Research And Indoor Thermal Performance Analysis Of Electrothermal Film Used In Heating

In consideration of the disadvantages of the traditional central heating, such as heat loss, environment pollution and so on. There has been a trend that professionals are researching and developing to look for a heating means which can reach the target of energy conservation and emission reduction. Electrothermal film heating has many advantages, such as high indoor thermal comfortable, high electro-thermal conversion rate, low cost, high control, clean energy and so on. So it is widely concerned by experts and scholars in this field.The process from products researches to actual application is continuous, which is a joint research result in multi-disciplinary field. The electrothermal film products mainly involve two major fields of materials and heating ventilation from research to application. By using the method of discipline-crossing research in those two fields, we can have a better understanding in indoor thermal performance of electrothermal film products, and develop the products which meet public demands.In this thesis, several formulations of conductive ink used in electrothermal film were designed, and electrothermal film specimens with different sizes according to those formulations were made. Then comparative experiments were made to test the electrothermal performance of electrothermal film specimens. The experimental results showed that the sizes of rectangular samples were300mm×15mm, and the ratios of matrix resin to conductive filler in the samples were6:4and5:5respectively. The samples surface heating temperature are maintained around43℃and50℃respectively at the AC220in ten minutes. The electrothermal film specimens of the two formulations can be applied in the floor heating and the wall heating respectively.The electrothermal films were selected; whose surface heating temperature and power density are the same as the trial samples. And the experiment test of indoor thermal performance for electrothermal film floor heating system and wall heating system were made. The test objects included temperature rise time, test point temperature, working frequency and energy consumption in24hours. The experimental results showed that using electrothermal film heating can make indoor temperature heat quickly in short time and distribute evenly. So the heating means has good feasibility and comfort.Basing on the theory of computational fluid dynamics (CFD), a physics model of test room was built and the heating process of electrothermal film dynamically was simulated with Fluent software. Test data were in agreement with simulated results which validated the effectiveness of the model. Analysis results showed that electrothermal film heating offers even temperature distribution in most indoor area. And its heating performance was much better than common convection heating. For electrothermal film floor heating can make the floor temperature higher, the comfort of floor heating was better than wall heating. Floor heating satisfied the the public requirement "cool head hot feet".By simulating the heating process of electrothermal film under different temperature control schemes, the work time of electrothermal film within24hours were calculated. The average costs of electrothermal film heating in Beijing were estimated by temperature control in different rooms and different time. The results showed that the cost of electrothermal film heating is lower than central heating. So electrothermal film heating can achieve the goal of energy conservation and emission reduction.