光纤光栅温度传感器在地源热泵中应用

FBG sensors for on-line temperature measurements of ground-source heat pump

地源热泵应用地下土壤的地热资源,为建筑冬季供暖和夏季制冷.为了实时监测地源热泵工作过程中垂直盘管换热器周围土壤温度的变化,应用3个自行研制的光纤光栅温度传感器,组成分布式光纤光栅温度监测系统对其进行监测.3个光纤光栅温度传感器分别安置在25 m垂直盘管的5、15和25 m处.垂直盘管安装完后,应用FBG波长解调系统采集数据.采用双层钢管封装的光纤光栅温度传感器,有效消除了应变对光纤光栅的影响,同时也提高了光纤光栅的温度灵敏度.该光纤光栅温度传感系统对地源热泵长期工作状态进行了监测,监测结果与理论计算结果符合很好.

Ground-source heat pump system utilizes the thermal energy of the underground soil to heat or cool a building. The monitoring of the on-line temperature distribution of the soil and the thermal difference of the circulating water system are discussed by （FBG） sensor system. Three Bragg grating sensors were placed at in an op terval tical fiber Bragg grating s of 10 m in a deep well with a length of 25 m. Data were collected immediately after the installation of the water pipes using a commercial FBG interrogation system. The sensors with double-steel tube were designed and packaged delicately to eliminate the influence of strain as well as to improve the thermal sensitivity. This FBG sensor system can monitor temperature fluctuation of ground-source heat pump for a long period, and the monitored results accord well with theoretical ones.