hot gas generator - HGG

所要求的“Großgerät”即热燃气发生器（HGG）将为发电厂工程和传热研究所（IKW）的三个测试模块提供热燃气。两个IKW工作组（WG）参与了该提案，WG废热回收应用的朗肯循环和WG传热。研究方向分为填料床和复杂管形结构两大领域。两个工作组的研究项目概述如下。废热回收应用的WG朗肯循环将为朗肯循环的整体优化设计过程开发一种新的方法。其目的是为工作流体、电路、朗肯循环元件的设计和尺寸找到一个组合优化。目前在文献中没有这样的优化方法，这将允许得出关于组件大小的结论。重点是扩展器的建模。这种工作引擎经过优化设计后，在动态系统中具有很大的潜力。研究所现有的有机朗肯循环测试模块应与HGG一起操作，为本项目提供数据基础。在填充床的研究领域，将研究和模拟辐射对单分散填充床传热的精确影响。温度高达800°C的测量将成为模型的基础。用于这些测量的热气体将由HGG提供。借助一种专门开发的图像识别方法，将粒子排列考虑在内，作为传热数值模型的基础。这样可以保证仿真和实验的几何相似性。数值模型的验证应采用测量数据进行。所获得的知识应扩展到多分散填充床。在复杂管形结构的研究领域中，主要研究了改善管形结构传热的被动和主动措施及其对压力损失的影响。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。测量的基础是由所要求的设备提供的热气流。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550至140.000的雷诺数，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.