Abstract: For the large scale heat exchanger networks(HEN),there are a mass of coupled temperatures. If these states cannot be controlled and observed,it will go against saving energy and safety in production.To implement control system,placing the temperature measuring points in the HEN properly is the basis.Generally,too many thermocouples are set by experience to ensure all states of the HEN are observable.But it is not cost-efficient and lack of verification by the control theory.Therefore,it is necessary to develop a method to design temperature measuring points of HEN based on the control theory. An optimal design method of temperature measuring points with all states observable was proposed by using structural observability and analysis of the impact of bypasses.The design could maintain all of states observable and minimize the number of temperature measuring points with the trade-off between observability and capital investment.With measuring points determined,the regulatory control system was proposed based on the relative gain array analysis.Consequently,a case study with HEN in a crude distillation unit demonstrated the effectiveness of the method proposed.

Key words: heat exchanger networks, structural observability;temperature measuring point, control system, optimal design

摘要： 复杂换热网络中间温度状态变量众多且变量间耦合严重，若不加以控制与观测，往往不利于物流间的热量传递与安全监测。换热网络的温度测点设置是实施控制的基础，为保证全部状态的可观性，凭经验设置的温度测点往往过多，经济性差，也缺乏理论论证与分析。因此从控制理论的角度，基于结构可观性理论分析换热网络的结构特性。分析旁路设置对换热网络结构可观性的影响，权衡可观性与经济性两方面因素，为实现设置最少的温度测点以满足全部状态的可观性要求，提出了换热网络全部状态可观的温度测点优化设计法。然后，基于相对增益分析，将已有旁路与优化得出的温度测点进行配对，构成换热网络的常规控制系统。最后，以某常减压蒸馏装置脱盐前换热网络为例验证了方法的可行性。

关键词: 换热网络, 结构可观性, 温度测点, 控制系统, 优化设计