The Performance Research Of The Photovoltaic Thermoelectric Fresh Air Ventilator

Energy shortage and environmental pollution facing society today has been becoming two major problems. New energy development and utilization mainly based on renewable energy have become the mainstream of diversified energy structure in the future. Under this kind of background, the photovoltaic power generation technology and the semiconductor cooling/heating technology have obtained the unceasing development because of its unique superiority respectively. This thesis combining solar photovoltaic technology and thermoelectric cooling/heating technology designs a new type of photovoltaic thermoelectric fresh air ventilator. The device is powered by photovoltaic module.Back of PV module is mounting air channel. In winter, outdoor fresh air flows through the air channel away, which not taking a part of heat of the photovoltaic panels but preheating fresh air. Then the preheated air is send to interior after the air is heat up at the heat side of thermoelectric module. At the same time, indoor exhaust air is discharged through the cold end of the thermoelectric module, not only to achieve the solar photovoltaic and photothermal active comprehensive utilization, but also recover the exhaust heat.Photovoltaic power model was firstly set up to calculate the power and power efficiency of the photovoltaic module with the actual solar radiation intensity and temperature. Then the improved zone model was adopted to establish the physical model of heat transfer in the ventilation type photovoltaic-thermal module, and the finite difference numerical simulation method was utilized to solve the model. Based on dynamic calculation method determining the internal parameters of thermoelectric chip, a thermoelectric model was built.The photovoltaic-thermal heat transfer model and the thermoelectric model were coupled. And two different systems were defined to evaluate the performance of the photovoltaic thermoelectric fresh air ventilator. Finally, outdoor environmental parameters one day were choosed to simulate, and the performance of the fresh air ventilator’s was analyzed when the operating voltage was 4V, 5V and 6V respectively. Compared with no fresh air preheating system, the effect on the fresh device whether the fresh flow preheated or not was investigated.The simulation results show that the temperature of the fresh air has gone up. During the time of strong solar radiation, the temperature difference between the air inlet and outlet can reach 1.81 in winter. When the solar radiation intensity is 784.76W/m~2, the power of the photovoltaic cell panel is 99.04W/m~2 and the power efficiency is 12.62%. The heat transfer coefficient of the fresh air device system with air preheated is 2.98 to 3.35. The heat transfer coefficient is 2.93 to 3.03 if there is no fresh air preheated. Thus the exhaust heat recovery and utilization are realized and the utilization rate of the solar radiation energy is improved by using the heat of the photovoltaic cell panel to preheat the fresh air. The system has a good performance advantage.The higher the operation voltage, the greater the heat flux at the end of the hot and cold side, which leads to decreasing the temperature difference between the hot and cold end of the thermoelectric chip and the coefficient of performance of the system. On the other hand, vice versa. At the premise of meeting the demand, the selection of small input voltage, the system performance will be better.