Canadian Journal of Chemical Engineering, Vol.91, No.10, 1686-1694, 2013
The relative exergy-destroyed array: A new tool for control structure design
Due to increasing energy demands, energy crises and strict environmental regulations, the eco-efficiency of all industrial processes and plants has become vitally important. Control loop configuration or control system structure determination is a major and vitally important activity in the complex task of process control because a poorly structured control strategy can lose much energy from the process or plant when implemented. To save this loss of energy due to a poorly structured control strategy, engineers need to find a way to integrate control loop configuration and measurements of eco-efficiency. In this paper, we present the relative exergy-destroyed array (REDA), a new tool to measure the relative eco-efficiency of a process. The REDA is a means to compare the eco-efficiency of multi-input multi-output processes for different combinations of control structures. Based on steady state information, it is a simple tool for comparing eco-efficiency. The results obtained from the REDA are interpreted and explained with the help of case studies involving a whole monochlorobenzene (MCB) plant and a heat exchanger network (HEN). The REDA may help guide the process designer to quickly find a control design with low operating costs and high eco-efficiency.
Keywords:relative exergy-destroyed array (REDA);exergy eco-efficiency factor (EEF);relative gain array (RGA);control configuration;process design