当前位置: X-MOL 学术Energy Build. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Development of chiller-attached apparatus for accurate initial ground temperature measurement: Insights from global sensitivity analysis of thermal response tests
Energy and Buildings ( IF 6.7 ) Pub Date : 2021-02-19 , DOI: 10.1016/j.enbuild.2021.110841
Wonjun Choi , Ruchi Choudhary , Ryozo Ooka

Local sensitivity analysis (LSA) is widely used for evaluating the uncertainty in a model output or estimated parameters. However, it does not consider the effect of changing parameter values in the parameter space and the simultaneous change of the parameter set. Global sensitivity analysis (GSA) overcomes these limitations of LSA by adequately representing the propagated uncertainty in model usage or parameter estimation. In this study, by using Sobol’s method, GSA was conducted to analyze the temporal uncertainty transition of model inputs required in the thermal property estimation via a ground thermal response test (TRT). The obtained results provide important insights; specifically, among the various input parameters, the initial ground temperature and ground volumetric heat capacity account for more than ~27% and ~20% of the total uncertainty in borehole resistance estimation, respectively. Further, the estimated borehole thermal resistance is larger than intended owing to the uncertainty in the borehole diameter, which is likely to increase during the construction process. Thus, a deterministic estimation by fixing the borehole diameter leads to a lower estimate than the actual resistance. Then, the insights obtained are used to develop a chiller-attached TRT apparatus to overcome the limitations of conventional apparatuses that cannot measure the initial ground temperature accurately. By using the developed apparatus that can accurately control the fluid temperature, the temperature at which the circulating fluid and surrounding soil are in thermal equilibrium can be asymptotically found with an uncertainty range of 0.1 °C. This improvement in the initial ground temperature accuracy results in a 24% reduction in the estimation uncertainty of the borehole thermal resistance compared to conventional practice.



中文翻译:

开发用于精确初始地面温度测量的冷水机组:从热响应测试的全局灵敏度分析中获得的见解

局部灵敏度分析(LSA)被广泛用于评估模型输出或估计参数中的不确定性。但是,它没有考虑更改参数空间中的参数值以及同时更改参数集的影响。全局敏感性分析(GSA)通过充分表示模型使用或参数估计中传播的不确定性,克服了LSA的这些限制。在这项研究中,通过使用Sobol方法,通过地面热响应测试(TRT)进行了GSA,以分析热属性估计中所需的模型输入的时间不确定性过渡。获得的结果提供了重要的见识;具体来说,在各种输入参数中,初始地面温度和地面体积热容分别占钻孔阻力估算总不确定度的约27%和20%以上。此外,由于钻孔直径的不确定性,估计的钻孔热阻比预期的大,这在施工过程中可能会增加。因此,通过固定钻孔直径的确定性估计导致的估计值低于实际阻力。然后,将获得的见解用于开发带有冷水机组的TRT设备,以克服无法准确测量初始地面温度的常规设备的局限性。通过使用可以精确控制流体温度的发达设备,可以渐近地找到循环流体和周围土壤处于热平衡状态的温度,不确定度范围为0.1°C。与常规做法相比,初始地面温度精度的这种提高导致钻孔热阻的估计不确定性降低了24%。

更新日期:2021-03-04
down
wechat
bug