부하 예측 모델을 활용한 외기 냉방 시스템의 제어 알고리즘 개발

Development of Control Algorithm for Economizer System using Load Prediction Model

An economizer system is one of the measures used to improve building energy efficiency by reducing the cooling load through the intake of outdoor air during the intermediate seasons. The economizer control method includes dry-bulb temperature and enthalpy controls. The dry-bulb temperature control considers only sensible heat and is limited in that humidity cannot be considered. Enthalpy control compensates for these limitations. The setpoint of the economizer system, namely the mixed air temperature and the high and low limits that determine the economizer control, are maintained at a constant. Therefore, under certain outdoor environment conditions, indoor comfort problems may occur and energy may be wasted. Therefore, it is necessary to develop an algorithm that controls the set value according to indoor and outdoor air conditions when controlling the economizer system. For this purpose, sensible and latent heat load prediction models were developed using MATLAB. In addition, an energy-prediction model was developed to derive the control set value in situations where energy consumption is minimal. And using the developed prediction model, a control algorithm that sets the set value variable when controlling the economizer system was developed. This algorithm was evaluated through a simulation and it was confirmed that the control of the economizer by the algorithm resulted in approximately 18% less energy expended compared to energy use under the existing control system.

An economizer system is one of the measures used to improve building energy efficiency by reducing the cooling load through the intake of outdoor air during the intermediate seasons. The economizer control method includes dry-bulb temperature and enthalpy controls. The dry-bulb temperature control considers only sensible heat and is limited in that humidity cannot be considered. Enthalpy control compensates for these limitations. The setpoint of the economizer system, namely the mixed air temperature and the high and low limits that determine the economizer control, are maintained at a constant. Therefore, under certain outdoor environment conditions, indoor comfort problems may occur and energy may be wasted. Therefore, it is necessary to develop an algorithm that controls the set value according to indoor and outdoor air conditions when controlling the economizer system. For this purpose, sensible and latent heat load prediction models were developed using MATLAB. In addition, an energy-prediction model was developed to derive the control set value in situations where energy consumption is minimal. And using the developed prediction model, a control algorithm that sets the set value variable when controlling the economizer system was developed. This algorithm was evaluated through a simulation and it was confirmed that the control of the economizer by the algorithm resulted in approximately 18% less energy expended compared to energy use under the existing control system.