In this work, a method of focal region flux characterization of Scheffler fixed focus concentrator is presented. Being a fixed focus concentrator, Scheffler dish serves as an ideal focusing unit for on-Sun testing of scaled down high pressure receiver designs under actual boundary conditions. Flux characterization is performed numerically by tracing the ray trajectories from their inception till the focal region and experimentally using point-based heat flux sensors. A circular plate is mounted at the focal region with five water cooled heat flux sensors attached. Four of these sensors are positioned around a diameter of size corresponding to an existing cavity receiver aperture diameter and one sensor is located at the plate centre. These sensors help to obtain the point based flux measurements in the region. Since the dish is not parabolic, a non-Gaussian flux profile is obtained, and spatial averaging of the flux data is performed analytically to obtain an averaged heat flux value. This averaged flux density is then matched with the spatially resolved flux map average value obtained from the numerical analysis. Average thermal power intercepted on the target surface is also measured, which serves as a useful procedure for estimating the radiative power incident on the receiver aperture. Further, as a demonstration exercise of the present fixed focus dish characterization method, a receiver testing methodology with an existing hybrid cavity and tubular design using compressed air is presented.

在这项工作中，提出了一种舍弗勒定焦聚光器焦区通量表征方法。作为一个定焦聚光器，Scheffler 碟作为理想的聚焦单元，可在实际边界条件下对按比例缩小的高压接收器设计进行日照测试。通量表征是通过跟踪从开始到焦点区域的射线轨迹并通过实验使用基于点的热通量传感器来以数值方式执行的。圆形板安装在焦点区域，并附有五个水冷热通量传感器。其中四个传感器位于与现有腔体接收器孔径相对应的尺寸直径周围，一个传感器位于板中心。这些传感器有助于获得该地区基于点的通量测量值。由于这道菜不是抛物线，获得非高斯通量分布，并对通量数据进行空间平均分析，以获得平均热通量值。然后将该平均通量密度与从数值分析获得的空间分辨通量图平均值相匹配。还测量了在目标表面截获的平均热功率，这是估算入射在接收器孔径上的辐射功率的有用程序。此外，作为本固定焦点碟形表征方法的演示练习，介绍了使用压缩空气的现有混合腔和管状设计的接收器测试方法。然后将该平均通量密度与从数值分析获得的空间分辨通量图平均值相匹配。还测量了在目标表面截获的平均热功率，这是估算入射在接收器孔径上的辐射功率的有用程序。此外，作为本固定焦点碟形表征方法的演示练习，介绍了使用压缩空气的现有混合腔和管状设计的接收器测试方法。然后将该平均通量密度与从数值分析获得的空间分辨通量图平均值相匹配。还测量了在目标表面截获的平均热功率，这是估算入射在接收器孔径上的辐射功率的有用程序。此外，作为本固定焦点碟形表征方法的演示练习，介绍了使用压缩空气的现有混合腔和管状设计的接收器测试方法。