Using the potential of energy losses in gas pressure reduction stations for producing power and fresh water
Section snippets
Abbreviations
- A (m2)
area
- APC
absorption power cycle
- BW
brine water
- c ($/kW)
cost per exergy unit
- ($/s)
cost rate
- CC
combine cycle
- CGS
city gate station
- CHP
combine heat and power
- CRF
capital recovery factor
- DW
disalination water
- EL
electric line
- Ex
exergy rate
- Exh
exhaust
- f
exergoeconomic factor
- GOR
gain output ration
- i
intrest rate
- LHV (kJ/kg)
lower heating value
- MED
multi effect desalination
- MS
motive steam
- NG
natural gas
- NPV
payback period
- P
power
- PEM
proton exchange membrane
- r
relative cost differenc
- RC
rankin cycle
- St
steam
- T (°C)
temperature
- TVC
System description
In CGSs, the pressure of gas is reduced to 1/4 of its initial pressure by means of pressure reducing valve. The common problem in CGSs is severe decrease in gas temperature during pressure reduction process which leads to freezing of gas and interruption of the gas flow. Water bath heaters are used to solve this problem. However, they waste most of the inlet energy through exhaust flow. Additionally, a significant amount of energy is also wasted during natural gas pressure reduction process
Design method
In this study, MED-TVC system is coupled with three CGSs with gas flow rates of 2.5, 5 and 11.5 kg/s as conventional CGS capacities in Iran. The proposed combined system is modelled based on mass conservation, energy conservation, exergy balance and exergoeconomic balance by means of EES. Then, the effective parameters in MED-TVC system are optimized using multi-objective optimization and optimal CGS capacity for employing desalination system is selected. The following assumptions are used in
Thermodynamic modeling
The proposed system in this study is composed of MED-TVC and CGS equipped with turboexpander. As described, the exhaust heat of the heater is used to produce steam to operate the MED-TVC. In this section, at first, the modeling of the turboexpander is presented and the heater's inlet and outlet temperatures are calculated. Then, based on the energy required for pre-heating of the natural gas, the heater exhaust heat is computed and MED-TVC is modelled.
Results and discussion
In this section, the modeling results for employing the proposed system in CGS with different capacities of 2.5, 5 and 11.5 kg/s is presented. Then, the optimization procedure is performed on effective parameters of the system such as TVC inlet temperature and pressure and first effect outlet temperature. Finally, the optimal CGS capacity for integrating the desalination system is selected through the optimization.
Conclusions
In this study, due to the high water shortage, the feasibility of employing the exhaust heat of CGS with different capacities in MED-TVC system as an integrated system is investigated. The proposed system is modelled based on energy-exergy-exergoeconomic analysis. Furthermore, the optimization process is performed on effective parameters such as TVC inlet temperature and pressure and first effect outlet temperature are optimized by means of multi-objective Pareto solution and TOPSIS method. The
CRediT authorship contribution statement
Mahdi Deymi-Dashtebayaz: Conceptualization, Methodology, Formal analysis, Supervision.
Daryoush Dadpour: Software, Data curation, Formal analysis, Writing- Original draft preparation.
Javad Khadem: Investigation. Writing- Reviewing and Editing.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References (42)
- et al.
Technoeconomic study of a novel integrated thermal MSF-MED desalination technology
Desalination
(Sep. 2015) - et al.
Comprehensive comparison on the ecological performance and environmental sustainability of three energy storage systems employed for a wind farm by using an emergy analysis
Energy Convers. Manag.
(2019) - et al.
Recent developments in thermally-driven seawater desalination: energy efficiency improvement by hybridization of the MED and AD cycles
Desalination
(Jan. 2015) - et al.
Investigating the prospects of water desalination using a thermal water pump coupled with reverse osmosis membrane
Desalination
(Nov. 2018) - et al.
Energy-water-environment nexus underpinning future desalination sustainability
Desalination
(Jul 2017) - et al.
Pilot studies on synergetic impacts of energy utilization in hybrid desalination system: multi-effect distillation and adsorption cycle (MED-AD)
Desalination
(March 2020) - et al.
Energy consumption and water production cost of conventional and renewable-energy-powered desalination processes
Renew. Sust. Energ. Rev.
(Aug. 2013) - et al.
CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: high efficiency assessment for different design options under the current legislative EU framework
Energy
(Nov. 2016) - et al.
Economic evaluation of Qeshm island MED-desalination plant coupling with different energy sources including fossils and nuclear power plants
Desalination
(Nov. 2017) - et al.
A novel study of using oil refinery plants waste gases for thermal desalination and electric power generation: energy, exergy & cost evaluations
Appl. Energy
(Jun. 2017)
Cost optimization of a combined power and water desalination plant with exergetic, environment and reliability consideration
Desalination
Operational analysis of the coupling between a multi-effect distillation unit with thermal vapor compression and a Rankine cycle power block using variable nozzle thermocompressors
Appl. Energy
Dynamic modeling of multi-effect desalination with thermal vapor compressor plant
Desalination
An experimental investigation on MEDAD hybrid desalination cycle
Appl. Energy
A multi evaporator desalination system operated with thermocline energy for future sustainability
Desalination
Multi-effect desalination plant combined with thermal compressor driven by steam generated by solar energy
Desalination
Thermal analysis of ME-TVC + MEE desalination systems
Desalination
Multi objective optimization of using the surplus low pressure steam from natural gas refinery in the thermal desalination process
J. Clean. Prod.
Modeling and genetic algorithm-based multi-objective optimization of the MED-TVC desalination system
Desalination
Exergy and thermo-economic analyses of a combined solar organic cycle with multi effect distillation (MED) desalination process
Desalination
Effect of feed flow arrangement and number of evaporators on the performance of multi-effect mechanical vapor compression desalination systems
Desalination
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