建筑内热源滞后冷负荷监测模型研究

Research on monitoring model of time-lag cooling load for internal heat sources in buildings

摘要:

准确获取内热源实时冷负荷对于制定供暖空调系统节能调控策略及降低建筑运行能耗具有重要意义,而辐射热传递过程产生的滞后冷负荷是内热源冷负荷计算的难点,为此,基于围护结构蓄放热规律、热传递特性及传递函数原理等建立内热源滞后冷负荷监测模型,该模型为10阶传递函数。为了简化计算过程、提高计算精度,利用辐射时间系数对该模型进行参数辨识及降阶分析,最终得到2阶传递函数。建立试验系统对模型进行验证,结果显示,模型的平均绝对百分比误差为8.19%。内热源滞后冷负荷监测模型可依托能耗监测平台实现负荷的在线监测,对描述滞后冷负荷的时间延迟规律及幅度衰减特性具有理论意义,为制定供暖空调系统节能调控策略提供理论依据。

Abstract:

Accurately acquiring real-time cooling load of internal heat sources is of great importance for developing energy-saving control strategies for heating and air conditioning systems and reducing the operating energy consumption of buildings. The delayed cooling load generated by the radiation heat transfer process poses a challenge in calculating the internal thermal load. In this paper, the radiant cooling load monitoring model of internal heat sources, represented by a 10th-order transfer function, is developed based on the analysis of heat storage-release process, heat transfer characteristics, and transfer function principle. In order to simplify the calculation process and improve the accuracy, radiant time factors are adopted to identify the parameters and reduce the order of developed models, and a transfer function of order 2 is acquired. An experimental system is built to validate the developed model and the results show an average absolute percentage error of 8.19% for the model. The developed model for thermal lag cooling load in buildings can be applied to building energy consumption monitoring platforms to achieve online load monitoring. It has theoretical significance in describing the time-delay patterns and amplitude attenuation characteristics of the delayed cooling loads. This model provides a theoretical basis for making energy-saving control strategy of the heating and air conditioning system.