Dynamic heat exchanger model for performance prediction and control system design of automotive waste heat recovery systems
Dynamic heat exchanger model for performance prediction and control system design of automotive waste heat recovery systems
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DOI：
10.1016/j.apenergy.2012.12.060
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发表时间：
2013-05-01
期刊：
影响因子：
11.2
通讯作者：
Ringler, Juergen
中科院分区：
文献类型：
--
作者：
Horst, Tilmann Abbe;Rottengruber, Hermann-Sebastian;Ringler, Juergen
通过朗肯循环回收废热是一种很有前途的方法，可以显著减少燃料消耗，从而减少乘用车发动机的废气排放。这种方法已经在工业应用中得到了很好的应用，例如天然气和蒸汽发电厂或船舶推进系统。虽然这些系统主要是为静态运行而设计的，但当原理转移到客车发动机上时，高动态运行条件下的行为变得更加重要。了解所用换热器的动态响应对于蒸汽循环的性能预测和控制系统设计具有重要作用。为此，本文采用动边界原理建立了废气换热器的动态模型。该模型描述了部件的设计操作和升温过程。为了在较宽的运行工况范围内获得较高的模型精度，开发了模拟壁面温度分布和区域切换的新方法。静态工作点的仿真以及系统输入变量对典型扰动的响应与试验台测量结果吻合良好。利用该模型开发了试验台动态运行控制系统。对运行特性的进一步研究揭示了不同的动态行为取决于从废气到工质的热流率以及蒸发压力和出口蒸汽温度的耦合。(C)2013爱思唯尔有限公司。保留所有权利。
Waste heat recovery by means of a Rankine Cycle is a promising approach for achieving significant reductions in fuel consumption and, as a result, exhaust emissions of passenger car engines. This approach is already well established in industrial applications such as gas and steam power plants or ship propulsion systems. While these systems are mainly designed for stationary operation, the behaviour in highly dynamic operating conditions becomes more important when the principle is transferred to a passenger car engine.Knowledge of the dynamic response of the employed heat exchangers plays an important role in performance prediction and control system design of the steam cycle. Hence, a dynamic model of the exhaust gas heat exchanger employing the moving-boundary principle was developed and is presented in this paper. The model describes both design operation and the heat-up procedure of the component. For achieving high model accuracy in the resulting broad range of operating conditions, new approaches for modelling wall temperature distribution and zone switching were developed.Simulations of stationary operating points as well as the response to typical disturbances of the system's input variables are in good agreement with test bench measurements. The model is used to develop a control system for dynamic operation on the test bench. Further studies of the operating characteristics reveal varying dynamic behaviour depending on the heat flow rate from exhaust gas to working fluid as well as coupling of evaporation pressure and outlet steam temperature. (C) 2013 Elsevier Ltd. All rights reserved.