시설원예용 복합열원 축열식 히트펌프시스템의 성능에 관한 시뮬레이션

Abstract

The introducing pollution and greenhouse effect issues should be taken enough consideration. The electricity consumption of refrigeration and air conditioning equipment is about 20% of the total electricity consumption. Therefore producing energy saving heat pump is very important to each country, manufacturer and consumers. Applying computer simulation in air conditioning system is favorable to save experiment expense, shorten the period of product development and reduce the cost. It has become the important means for studying the system characteristic and optimizing the components. To study the effects of solar energy, outdoor air temperature and wind speed on inside air temperature in the plastic greenhouse, a model for forecasting the greenhouse air temperature was established in this study on the basis of the energy and mass balance theory. Application of solar energy to the greenhouse is major area in the renewable energy research and development in order to save energy. Recently, considering the safety and efficiency of the heat pump, clean energy such as geothermal and solar energy has received much attention. The system is installed at a 50㎡ greenhouse which located in jocheon-ri of Jeju Province. Experiments were carried out to collect data to validate the model. The results showed that the simulated air temperature inside a plastic greenhouse agreed well with the measured data. In this study, the development of heat pump simulation study is researched. The simulation program is written by Engineering Equation Solver. It is very convenient and shortcut to call these thermal properties, which provides favorable base for simulation. The computation model for each component in the heat pump system is built. The compressor numerical model is built for full hermetic scroll types. The simulation results are satisfactory with the experimental comparison. The numerical model of refrigerant charge is built. The numerical models of condenser and evaporator are built and the effect of tube dimension, fin type on the heat transfer performance is analyzed, which provides some reference for enhancement heat exchanger. The development of heat pump energy efficiency standard is studied. The level of air cooled heat pump energy efficiency ratio is compared with each other for different capacity range. In conclusion, improving the energy efficiency standard and increasing the energy efficiency ratio of the heat pump equipment are important for developing the energy saving research of refrigeration equipment. According to the results of simulation, the error of the simulation results with the experimental results is less than 5%. So simulation results are correct. The temperature inside greenhouse increased with the rising of quantity of solar radiation or outdoor temperature. But the temperature inside greenhouse and reduced with the rising of wind speed. With the increase of the condensation temperature compressor power increased. When changing the outdoor temperature and air volume conditions. The largest heating capacity 21.76kW and largest COP 7.1 was computed when the outdoor temperature was 10℃ and air volume was 50㎥/min at heat storage tank source heating mode. And largest heating capacity 21.05kW and largest COP 8.1 was computed when the outdoor temperature was 10℃ and air volume was 40㎥ /min at outdoor air source heating mode.