An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study inv...An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study investigated the feasibility and benefits of explosion-proof dual throttling cooling and dehumidification air-conditioning system applied to the explosion-proof frequency converter. The physical model of dual throttling air-conditioning system was established and its performance parameter was described by mathematical method. The design calculation of the system has also been done. The experimental result showed that the system reached the steady state at the refrigeration mode after running 45 min, and the maximum internal temperature of the flame-proof cavity was 31.0 ℃. The system reached the steady state at the dehumidification mode after running 37 min. The maximum internal relative humidity and temperature of the flame-proof cavity were 33.4% and 36.3 ℃, respectively. Therefore, the proposed system had excellent ability of heat dissipation and avoided internal dewing. Compared with water cooling system, it was more energy-saving and economical. The airflow field of dual throttling air-conditioning system was also studied by CFD simulation. It was found that the result of CFD numerical simulation was highly consistent with the experimental data.展开更多
该文通过宽量程低分辨率和窄量程高分辨率两个流量传感器组合使用实现双压差节流式呼气流量测量,低成本和精准获得用力肺活量(Forced Vital Capacity,FVC)、第一秒用力肺活量(Forced Expiratory Volume in One Second,FEV1)和1秒率(FEV1...该文通过宽量程低分辨率和窄量程高分辨率两个流量传感器组合使用实现双压差节流式呼气流量测量,低成本和精准获得用力肺活量(Forced Vital Capacity,FVC)、第一秒用力肺活量(Forced Expiratory Volume in One Second,FEV1)和1秒率(FEV1/FVC(%))等筛查慢性阻塞性肺疾病(Chronic Obstructive Pulmonary Disease,COPD)的量化指标。并与英国迈科ML3500肺功能仪进行了有效性验证,结果表明两款设备的FVC和FEV1相关性分别为0.998和0.999,配对t检验的P值均大于0.05,FVC、FEV1和FEV1/FVC(%)的Bland-Altman分析显示三个参数的测量结果均有90%以上落在一致性区间内。因此,该设备可提供准确的FVC和FEV1测量,对于提高中国COPD有效筛查和知晓率具有重要意义。展开更多
基金Supported by the National Basic Research Program of China("973"Program,No.2009CB219907)
文摘An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study investigated the feasibility and benefits of explosion-proof dual throttling cooling and dehumidification air-conditioning system applied to the explosion-proof frequency converter. The physical model of dual throttling air-conditioning system was established and its performance parameter was described by mathematical method. The design calculation of the system has also been done. The experimental result showed that the system reached the steady state at the refrigeration mode after running 45 min, and the maximum internal temperature of the flame-proof cavity was 31.0 ℃. The system reached the steady state at the dehumidification mode after running 37 min. The maximum internal relative humidity and temperature of the flame-proof cavity were 33.4% and 36.3 ℃, respectively. Therefore, the proposed system had excellent ability of heat dissipation and avoided internal dewing. Compared with water cooling system, it was more energy-saving and economical. The airflow field of dual throttling air-conditioning system was also studied by CFD simulation. It was found that the result of CFD numerical simulation was highly consistent with the experimental data.
