Investigation of Unsteady Thermal Performance of Multi-Effect Desalination with Thermal Vapor Compression

Document Type : Research Article

Authors

1 Shahroud University of Technology, Shahroud, Iran

2 Shahrood Univ.

3 SUT

Abstract

Due to the high use of thermal desalination plants, there is a great tendency to simulate their behavior. Most of the research is focused on modeling steady behavior, but to design control systems and evaluate their performance, we also need to study unsteady behavior. Also, few researchers have studied the system shutdown. In this paper, steady and unsteady modeling of an industrial multi-effect desalination plant with four effects, one condenser, and a Thermo compressor has been studied. The variable-step, variable-order method has been used to solve differential equations. Each evaporator is divided into three phases of vapor, tubes, and brine then the equations of mass and energy conservation are used. Results have been validated with real plant data. The variables of temperature, vapor flow rate, brine flow rate and brine level were studied in unsteady modeling in starting, shutting down, and steady-state conditions. It was found that the largest change in the brine flow rate after shutting down is in the last effect, which increases by 42%. Also, the biggest change in the level of the brine is in the first effect, which after 800 seconds will reach 11 times the steady state that will cause the flooding phenomenon.

Keywords

Main Subjects

References

[1] M.C. Georgiou, A.M. Bonanos, A transient model for forward and parallel feed MED, Desalination and Water Treatment, 57(48-49) (2016) 23119-23131.
[2] A. Cipollina, M. Agnello, A. Piacentino, A. Tamburini, B. Ortega, P. Palenzuela, D. Alarcon, G. Micale, A dynamic model for MED-TVC transient operation, Desalination, 413 (2017) 234-257.
[3] M.L. Elsayed, O. Mesalhy, R.H. Mohammed, L.C. Chow, Effect of disturbances on MED-TVC plant characteristics: Dynamic modeling and simulation, Desalination, 443 (2018) 99-109.
[4] M.L. Elsayed, O. Mesalhy, R.H. Mohammed, L.C. Chow, Transient performance of MED processes with different feed configurations, Desalination, 438 (2018) 37-53.
[5] L. Guimard, A. Cipollina, B. Ortega-Delgado, G. Micale, F. Couenne, P. Bandelier, C. Jallut, New considerations for modelling a MED-TVC plant under dynamic conditions, Desalination, 452 (2019) 94-113.
[6] Z. Dong, M. Liu, X. Huang, Y. Zhang, Z. Zhang, Y. Dong, Dynamical modeling and simulation analysis of a nuclear desalination plant based on the MED-TVC process, Desalination, 456 (2019) 121-135.
[7] A.E. Hakim, A. Abouelsoud, R. Abobeah, E.E. Ebrahiem, Enhancement of Feed Forward Multi Effect Evaporator Performance for Water Desalination Using PI Control, Journal of Advanced Engineering Trends,  (2020).
[8] J. Hua, L. Wua, Y. Wangb, W. Zhanga, Y. Hua, Dynamic modeling and simulation of the multi-effect distillation desalination process, DESALINATION AND WATER TREATMENT, 217 (2021) 31-41.
[9] H. El-Dessouky, H. Ettouney, I. Alatiqi, G. Al-Nuwaibit, Evaluation of steam jet ejectors, Chemical Engineering and Processing: Process Intensification, 41(6) (2002) 551-561.
[10] M.M. Ashour, Steady state analysis of the Tripoli West LT-HT-MED plant, Desalination, 152(1-3) (2003) 191-194.
[11] H.-J. Joo, H.-Y. Kwak, Performance evaluation of multi-effect distiller for optimized solar thermal desalination, Applied thermal engineering, 61(2) (2013) 491-499.
Amirkabir Journal of Mechanical Engineering
Volume 54, Issue 7
October 2022
Pages 1623-1646

Files

Share

How to cite

Statistics