hot gas generator - HGG

所要求的“Großgerät”即热气发生器（HGG）将为电厂工程和传热研究所（IKW）的三个测试模块提供热气。两个IKW工作组（WG）参与了这一建议，工作组朗肯循环余热回收应用和工作组传热。WG传热被分为研究领域填充床和复杂的管几何形状。这两个工作组的研究项目概述如下。工作组朗肯循环余热回收应用将开发一种新的方法，为朗肯循环的整体优化设计过程。目的是找到一个最佳的工作流体，电路，朗肯循环部件的设计和尺寸的组合。目前，在文献中没有指定这样的优化方法，这将允许得出关于组件尺寸的结论。重点是膨胀器的建模。这种工作发动机在优化设计时在动态系统中具有巨大的潜力。该研究所现有的有机朗肯循环测试模块应与HGG一起运行，为该项目提供数据基础。在填充床研究领域，将研究辐射对单分散填充床传热的精确影响并建立模型。在高达800 °C的温度下进行的测量将成为模型的基础。用于这些测量的热气将由HGG提供。借助专门开发的图像识别方法，将颗粒排列考虑在内，作为传热数值模型的基础。这将确保模拟和实验的几何相似性。数值模型的验证应通过使用测量数据进行。所获得的知识应扩展到多分散填料床。在复杂管几何形状的研究领域，被动和主动的措施，以改善传热和压力损失的影响进行了研究。 被动措施是纵向扭曲和表面加深管。主动措施是表面振动和声激励。传热和压力损失将在数值模型中进行研究，并与实验数据进行比较。测量的基础是所需设备提供的热气流。测量将在整个质量流量和温度范围内进行。这导致在20 - 800 °C范围内的雷诺数为550至140.000，因此也涵盖高温应用。

The requested „Großgerät“ namely the hot gas generator (HGG) will provide the hot gas for three testing modules of the Institute of Power Plant Engineering and Heat Transfer (IKW). Two IKW working groups (WG) are involved in this proposal, the WG Rankine Cycle for Waste Heat Recovery Applications and the WG Heat Transfer. The WG heat transfer is divided into the research areas Packed Beds and Complex Tube Geometries. The research projects of both WGs are outlined below.The WG Rankine Cycle for Waste Heat Recovery Applications will develop a novel approach for a holistic optimal design process of Rankine cycles. The aim is to locate a combined optimum for the working fluid, the circuitry, the design and the size of the Rankine cycle components. Currently no such optimization method is specified in the literature which would allow conclusions to be drawn about the size of the components. The focus is on the modeling of the expander. This working engine when optimally designed offers great potential in dynamic systems. The existing Organic Rankine Cycle testing module at the institute should be operated with the HGG to provide a basis of data for this project.In the research area of Packed Beds, the precise influence of radiation on heat transfer in monodisperse packed beds will be investigated and modeled. Measurements at temperatures up to 800 °C will form a base for the models. The hot gas for these measurements will be provided by the HGG. With the help of a specially developed method for image recognition, it is intended to take the particle arrangement into account to serve as a basis for numerical models of heat transfer. This will ensure geometric similarity of simulation and experiment. The validation of the numerical models shall be carried out by means of using measurement data. The gained knowledge shall be extended to polydisperse packed beds.In the research area of Complex Tube Geometries passive and active measures are to be investigated with regard to the improvement of the heat transfer and their influence on the pressure loss. Passive measures are longitudinal twisted and surface deepened tubes. Active measures are surface vibrations and acoustic excitations. Heat transfer and pressure loss will be investigated in numerical models and compared with experimental data. The basis for the measurements is the hot gas flow provided by the requested device. The measurements will be carried out over the entire mass flow and temperature range. This leads to Reynolds numbers of 550 to 140.000 in the range of 20 - 800 °C and thus also covers high-temperature applications.