Operation of Dividing-Wall Columns. 1. A Simplified Temperature Difference Control Scheme

2013 ◽  
Vol 52 (7) ◽  
pp. 2642-2660 ◽  
Author(s):  
Shujun Luan ◽  
Kejin Huang ◽  
Ning Wu
Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 116 ◽  
Author(s):  
Xing Qian ◽  
Rui Liu ◽  
Kejin Huang ◽  
Haisheng Chen ◽  
Yang Yuan ◽  
...  

An effective process intensification strategy based on dividing walls shows promising energy-saving results for distillation processes. The three-product Petlyuk dividing wall distillation columns (DWDCs) are able to save approximately 30% energy in comparison with the traditional distillation columns. Furthermore, the four-product extended Petlyuk DWDC reduces about 50% of operation costs than conventional distillation sequences. Although researchers have extensively studied control schemes for the three-product Petlyuk DWDC, relatively little work has been done on the four-product extended Petlyuk DWDC. This paper studies feasible temperature control schemes containing temperature control scheme (TC), simplified temperature difference control scheme (STDC), and simplified double temperature difference control scheme (SDTDC) for the four-product extended Petlyuk DWDC. STDC and SDTDC are introduced so as to improve the dynamic performances with simple control schemes. All three control schemes are tested against a series of feed compositions and feed rate disturbances. Dynamic performances prove that the proposed STDC and SDTDC schemes are better at handling the inserted feed disturbances. These are very encouraging results for industrialization of the four-product extended Petlyuk DWDC in the future.


Author(s):  
Vinodhini M.

The objective of this paper is to develop a Direct Model Reference Adaptive Control (DMRAC) algorithm for a MIMO process by extending the MIT rule adopted for a SISO system. The controller thus developed is implemented on Laboratory interacting coupled tank process through simulation. This can be regarded as the relevant process control in petrol and chemical industries. These industries involve controlling the liquid level and the flow rate in the presence of nonlinearity and disturbance which justifies the use of adaptive techniques such as DMRAC control scheme. For this purpose, mathematical models are obtained for each of the input-output combinations using white box approach and the respective controllers are developed. A detailed analysis on the performance of the chosen process with these controllers is carried out. Simulation studies reveal the effectiveness of proposed controller for multivariable process that exhibits nonlinear behaviour.


WCET Journal ◽  
2019 ◽  
pp. 18-22
Author(s):  
Hiske Smart ◽  
Eman Al Al Jahmi ◽  
Ebrahim Buhiji ◽  
Sally-Anne Smart

Industrial infrared thermometry devices are large and, despite being less expensive than the current gold standard Exergen Dermatemp medical infrared thermometer, are still not affordable enough to ensure unrestricted and consistent use of this assessment modality in regular wound-related day-to-day practice. An increased skin surface temperature differentiation of 3°F associated with a wound has a positive predictive ability to detect deep or surrounding wound infection. This study hypothesised that inexpensive, pen- or pocket-sized, no-touch surface infrared thermometry devices will be equal in ability to detect a 3oF increased skin temperature compared to the Exergen Dermatemp infrared device and be reliable in the hands of any wound assessor. The odds of the control and other thermometers to detect a 3oF temperature difference, irrespective of the raters, were achieved in all five of the mini thermometers tested, with a correct temperature difference prediction that occurred in 90.933% of the times (odds determined 9/10). As a result of this study mini, no-touch infrared thermometry, to detect a 3oF temperature difference in wound assessment to determine tendency, could be implemented into primary health care clinics, rural clinics, day-to-day hospital practice and standard outpatients departments at a small financial cost, regardless of which thermometer is put to use.


2020 ◽  
Vol 20 (3) ◽  
pp. 71-78
Author(s):  
Yong-Hyeog Kang ◽  
◽  
Wonhyung Park

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