hot gas generator - HGG

所需的“Groçgerät”即热气发生器(HGG)将为发电厂工程与传热研究所(IKW)的三个测试模块提供热气。两个IKW工作组(WG)参与了这项提议，WG Rankine循环用于余热回收应用和WG热传输。WG换热分为填充床和复杂管型两个研究领域。WG朗肯循环的余热回收应用将为朗肯循环的整体优化设计提供一种新的途径。其目的是为朗肯循环部件的工作流体、电路、设计和尺寸找到最佳组合。目前，文献中没有指定这样的优化方法，该方法允许得出关于部件大小的结论。重点放在膨胀机的建模上。这种工作引擎经过优化设计后，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一起操作，为该项目提供数据基础。在填充床研究领域，将对单分散填充床中辐射对传热的精确影响进行研究和建模。温度高达800摄氏度的测量将构成模型的基础。这些测量所需的热气将由HGG提供。借助于一种专门开发的图像识别方法，它旨在将颗粒排列考虑在内，作为传热数值模型的基础。这将保证仿真和实验的几何相似性。应利用测量数据对数值模型进行验证。在复杂管型的研究领域，需要研究被动和主动的强化换热措施及其对压力损失的影响。被动措施是纵向扭转和表面加深的管子。主动测量是表面振动和声学激励。将在数值模型中对换热和压力损失进行研究，并与实验数据进行比较。测量的基础是由所请求的装置提供的热气流。测量将在整个质量流量和温度范围内进行。这导致雷诺数在20-800°C范围内为550-140.000，因此也适用于高温应用。

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.