熔盐槽式集热回路夜间热损失特性研究

NIGHTTIME THERMAL LOSS CHARACTERISTICS OF MOLTEN SALT PARABOLIC TROUGH LOOPS

为研究以熔盐作为传热介质的槽式光热电站集热回路夜间低速循环工况的热损失特性,首先利用辐射热网络法和传热热阻原理建立集热管稳态传热模型,通过与典型实验数据对比,验证该模型的适用性和准确性。在此基础上,考察在夜间熔盐低速循环工况下,集热回路长度、环境温度、风速、熔盐流速、熔盐入口温度、集热管真空度等因素对集热回路热损失的影响。研究表明,回路长度、熔盐流速、熔盐入口温度和集热管真空度是集热回路夜间热损失性能的主要影响因素;相比之下,环境温度和风速对热损失的影响较小。

To investigate the thermal loss characteristics of the parabolic trough loops using molten salt as heat transfer fluid at night,the steady-state heat transfer model for the typical trough collector was established based on the energy balance and thermal resistance model.Good agreement was obtained between numerical results and experimental data,validating the applicability and accuracy of the model developed.On this basis,the effects of loop length,ambient temperature,wind velocity,molten salt velocity,molten salt inlet temperature and the vacuum level on thermal loss were systematically analyzed.Results indicated that,during the night condition,the loop length,molten salt velocity,molten salt inlet temperature and vacuum level are main influence factors for thermal loss performance.By contrast,the ambient temperature and wind speed have little influence.