This page has only limited features, please log in for full access.
As the leading thermal desalination method, multistage flash (MSF) desalination plays an important role in obtaining freshwater. Its dynamic modeling and dynamic performance prediction are quite important for the optimal control, real-time optimal operation, maintenance, and fault diagnosis of MSF plants. In this study, a detailed mathematical model of the MSF system, based on the first principle and its treatment strategy, was established to obtain transient performance change quickly. Firstly, the whole MSF system was divided into four parts, which are brine heat exchanger, flashing stage room, mixed and split modulate, and physical parameter modulate. Secondly, based on mass, energy, and momentum conservation laws, the dynamic correlation equations were formulated and then put together for a simultaneous solution. Next, with the established model, the performance of a brine-recirculation (BR)-MSF plant with 16-stage flash chambers was simulated and compared for validation. Finally, with the validated model and the simultaneous solution method, dynamic simulation and analysis were carried out to respond to the dynamic change of feed seawater temperature, feed seawater concentration, recycle stream mass flow rate, and steam temperature. The dynamic response curves of TBT (top brine temperature), BBT (bottom brine temperature), the temperature of flashing brine at previous stages, and distillate mass flow rate at previous stages were obtained, which specifically reflect the dynamic characteristics of the system. The presented dynamic model and its treatment can provide better analysis for the real-time optimal operation and control of the MSF system to achieve lower operational cost and more stable freshwater quality.
Qiu-Yun Huang; Ai-Peng Jiang; Han-Yu Zhang; Jian Wang; Yu-Dong Xia; Lu He. Dynamic Modelling and Simulation of a Multistage Flash Desalination System. Processes 2021, 9, 522 .
AMA StyleQiu-Yun Huang, Ai-Peng Jiang, Han-Yu Zhang, Jian Wang, Yu-Dong Xia, Lu He. Dynamic Modelling and Simulation of a Multistage Flash Desalination System. Processes. 2021; 9 (3):522.
Chicago/Turabian StyleQiu-Yun Huang; Ai-Peng Jiang; Han-Yu Zhang; Jian Wang; Yu-Dong Xia; Lu He. 2021. "Dynamic Modelling and Simulation of a Multistage Flash Desalination System." Processes 9, no. 3: 522.
Multi-stage flash (MSF) desalination plays an important role in achieving large-scale fresh water driven by thermal energy. In this paper, based on first-principle modeling of a typical multi-stage flash desalination system, the effects of different operational parameters on system performance and operational optimization for cost saving were extensively studied. Firstly, the modelled desalination system was divided into flash chamber modules, brine heater modules, mixed modules and split modules, and based on energy and mass conservation laws the equations were formulated and put together to describe the whole process model. Then, with physical parameter calculation the whole process was simulated and analyzed on the platform of MATLAB, and the water production performance effected by operational parameters such as the feed temperature of seawater, the recycle brine from the discharge section, steam temperature and flowrate of recycled brine were discussed and analyzed. Then, the optimal operation to achieve maximize GOR (gained output ratio) with fixed freshwater demand was considered and performed, and thus the optimal flowrate of recycled brine, steam temperature, and seawater output flowrate from rejection section were obtained based on the established model. Finally, considering that minimizing the daily operational cost is a more rational objective, the operational cost equations were formulated and the optimal problem to minimize the daily operational cost was solved and the optimal manipulated variables at different hours were obtained. The study results can be used for guideline of real time optimization of the MSF system.
Hanhan Gao; Aipeng Jiang; Qiuyun Huang; Yudong Xia; Farong Gao; Jian Wang. Mode-Based Analysis and Optimal Operation of MSF Desalination System. Processes 2020, 8, 794 .
AMA StyleHanhan Gao, Aipeng Jiang, Qiuyun Huang, Yudong Xia, Farong Gao, Jian Wang. Mode-Based Analysis and Optimal Operation of MSF Desalination System. Processes. 2020; 8 (7):794.
Chicago/Turabian StyleHanhan Gao; Aipeng Jiang; Qiuyun Huang; Yudong Xia; Farong Gao; Jian Wang. 2020. "Mode-Based Analysis and Optimal Operation of MSF Desalination System." Processes 8, no. 7: 794.
This paper proposes a stochastic optimization framework for scheduling of a large-scale parallel-unit seawater reverse osmosis (SWRO) desalination plant. Two kinds of uncertainties, water consumption fluctuation and RO units malfunction, are considered. A combination scheduling frame including two routes, a robust pre-scheduling and a reactive rescheduling, is built to handle these two uncertainties. Both optimal scheduling problems are built as change constrained models, and the Monte Carlo method is used to solve the uncertainty problems. An improved genetic algorithm is constructed to compute the efficient solutions. The simulation results show that prescheduling can greatly overcome the effect of water consumption fluctuations, and the reactive rescheduling can improve the behaviours of dynamic operation.
Jian Wang; Chao Zheng; Wentao Shen; Chunhua Zhang; Haokun Wang; Aipeng Jiang. Scheduling of Seawater Reverse Osmosis Desalination under Two Kinds of Uncertain Factors. 16th European Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering 2018, 44, 1537 -1542.
AMA StyleJian Wang, Chao Zheng, Wentao Shen, Chunhua Zhang, Haokun Wang, Aipeng Jiang. Scheduling of Seawater Reverse Osmosis Desalination under Two Kinds of Uncertain Factors. 16th European Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering. 2018; 44 ():1537-1542.
Chicago/Turabian StyleJian Wang; Chao Zheng; Wentao Shen; Chunhua Zhang; Haokun Wang; Aipeng Jiang. 2018. "Scheduling of Seawater Reverse Osmosis Desalination under Two Kinds of Uncertain Factors." 16th European Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering 44, no. : 1537-1542.
A test system for the air resistance of plate fin heat exchanger (PFHE) in an open environment was developed. A combination of three nozzles is used to measure the air volume flowrate through the PFHE. The combination of three nozzles keeps the pressure difference between their two ends less than 800Pa, therefore a high precision measurement is implemented. The influence of temperature & humidity on the density of wet air in the open environment is discussed, and the variety of Reynolds number with the change of humidity is analysed. A compensation formula is present to cope with the fluctuation of temperature and humidity. An expert fuzzy-PID controller is developed to control the air volume flowrate with a faster speed and higher precision. The results show that the performance of the proposed measurement system is satisfied.
Jian Wang; Tong Chen; Jingqing Wang; Mingming Che; Shu Jiangzhou. Study on the Measurement of Air Resistance of Plate Fin Heat Exchanger in an Open Environment. 16th European Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering 2018, 44, 265 -270.
AMA StyleJian Wang, Tong Chen, Jingqing Wang, Mingming Che, Shu Jiangzhou. Study on the Measurement of Air Resistance of Plate Fin Heat Exchanger in an Open Environment. 16th European Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering. 2018; 44 ():265-270.
Chicago/Turabian StyleJian Wang; Tong Chen; Jingqing Wang; Mingming Che; Shu Jiangzhou. 2018. "Study on the Measurement of Air Resistance of Plate Fin Heat Exchanger in an Open Environment." 16th European Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering 44, no. : 265-270.