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Optimization of heat source side technical scheme of combined heat and water system based on a coal-fired power plant

Abstract

Recovering the waste heat (WH) of a power plant can conserve energy and reduce emissions. Scholars have proposed utilizing the WH of power plants in a combined heat and water (CHW) system, which is considered an economical, energy-saving, and environment-friendly way to integrate water and heat supply into long-distance transportation in urban areas of northern China. However, to date, a detailed design of the case on the heat source side of the CHW has not been developed. Therefore, in this study, the heat source side of a CHW system was divided into two cases: a single-generator set and a double-generator set, and both cases were optimized. The parameters of a multi-effect desalination (MED) process were examined; the optimal number of evaporation stages during the MED process was 12, and the optimal heat source temperature during the first stage was 70 °C. Then, by matching the extraction and exhaust steam flows, the WH of the exhaust steam in the heating season was finally utilized. Further, under each case optimal conditions, energy, exergy, and cost were analyzed. The results showed that the exergy efficiency in the heating season for each case was approximately 50%, whereas that in the non-heating season was approximately 3.5%. The economy and water quality of the single-generator case were better than those of the double-generator case. However, the absorption heat pump required in the single-generator case is difficult to realize because it operates under two working conditions.

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Abbreviations

A:

absorber in AHP

AHP:

absorption heat pump

C:

condenser in AHP

CHW:

combined heat and water

CHP:

combined heat and power

CSW:

concentrated seawater

DW:

desalinated water

E:

evaporator in AHP

E-i :

i-th effect evaporator of MED device

FSW:

feed seawater

G:

generator in AHP

HE:

heat exchanger

IPC:

intermediate-pressure cylinder

LPC:

low-pressure cylinder

MED:

multi-effect desalination

RO:

reverse osmosis

SW:

seawater

WH:

waste heat

YR-i :

i-th preheater of MED device

AM:

annual total cost (100 million yuan)

COP:

coefficient of performance

EM:

annual operation cost of total electricity consumed (100 million yuan)

E DW :

exergy of freshwater (kW)

E in :

sum of the exergy input to the system (kW)

E out :

sum of the exergy output from the system to the external environment (kW)

ΔE :

sum of all exergy losses of the system (kW)

GOR:

gained output ratio

G z :

total annual freshwater output (10000 t)

h[i]:

enthalpy of fluid entering or leaving the i-th effect of MED (kJ/kg)

IM:

initial investment

MRM:

annual operation cost of RO membrane replacement (100 million yuan)

PTM:

annual operating cost of pretreatment drugs (100 million yuan)

q[i]:

flow of fluid entering or leaving the i-th effect of MED (t/h)

Q z :

the total heat supply in the heating season (10000 GJ)

RE:

annual reduced generation (kWh)

S z :

total heat transfer area of the system (10000 m2)

s :

heat transfer area/unit DW (m2/t)

WPE:

annual electricity consumption of the water pumps and other equipment (kWh)

x[i]:

mass concentration of fluid entering or leaving the i-th effect of MED (%)

σ :

exergy efficiency (%)

References

  • Abd Elrahman MA, Abdo S, Hussein E, et al. (2020). Exergy and parametric analysis of freeze desalination with reversed vapor compression cycle. Thermal Science and Engineering Progress, 19: 100583.

    Google Scholar 

  • Abid A, Jamil MA, us Sabah N, et al. (2021). Exergoeconomic optimization of a forward feed multi-effect desalination system with and without energy recovery. Desalination, 499: 114808.

    Google Scholar 

  • Ahmad NA, Goh PS, Yogarathinam LT, et al. (2020). Current advances in membrane technologies for produced water desalination. Desalination, 493: 114643.

    Google Scholar 

  • Al-Hotmani OMA, Al-Obaidi MA, Patel R, et al. (2019). Performance analysis of a hybrid system of multi effect distillation and permeate reprocessing reverse osmosis processes for seawater desalination. Desalination, 470: 114066.

    Google Scholar 

  • Anand B, Shankar R, Murugavelh S, et al. (2021). A review on solar photovoltaic thermal integrated desalination technologies. Renewable and Sustainable Energy Reviews, 141: 110787.

    Google Scholar 

  • Caldera U, Breyer C (2020). Strengthening the global water supply through a decarbonised global desalination sector and improved irrigation systems. Energy, 200: 117507.

    Google Scholar 

  • Chen C, Luo X, Wang T, et al. (2021a). Minimum motive steam consumption on full cycle optimization with cumulative fouling consideration for MED-TVC desalination system. Desalination, 507: 115017.

    Google Scholar 

  • Chen J, Zheng W, Kong Y, et al. (2021b). Case study on combined heat and water system for nuclear district heating in Jiaodong Peninsula. Energy, 218: 119546.

    Google Scholar 

  • Delcroix B, Ny JL, Bernier M, et al. (2021). Autoregressive neural networks with exogenous variables for indoor temperature prediction in buildings. Building Simulation, 14: 165–178.

    Google Scholar 

  • DeLovato N, Sundarnath K, Cvijovic L, et al. (2019). A review of heat recovery applications for solar and geothermal power plants. Renewable and Sustainable Energy Reviews, 114: 109329.

    Google Scholar 

  • Eke J, Yusuf A, Giwa A, et al. (2020). The global status of desalination: An assessment of current desalination technologies, plants and capacity. Desalination, 495: 114633.

    Google Scholar 

  • Elsaid K, Kamil M, Sayed ET, et al. (2020a). Environmental impact of desalination technologies: A review. Science of the Total Environment, 748: 141528.

    Google Scholar 

  • Elsaid K, Sayed ET, Abdelkareem MA, et al. (2020b). Environmental impact of emerging desalination technologies: A preliminary evaluation. Journal of Environmental Chemical Engineering, 8: 104099.

    Google Scholar 

  • Fellaou S, Ruiz-Garcia A, Gourich B (2021). Enhanced exergy analysis of a full-scale brackish water reverse osmosis desalination plant. Desalination, 506: 114999.

    Google Scholar 

  • Fitó J, Hodencq S, Ramousse J, et al. (2020). Energy- and exergy-based optimal designs of a low-temperature industrial waste heat recovery system in district heating. Energy Conversion and Management, 211: 112753.

    Google Scholar 

  • Fu L, Li Y (2020). Long-distance heat-supply mode with large temperature difference using waste heat of power plants. Huadian Technology, 42(11): 56–61. (in Chinese)

    Google Scholar 

  • Fu L, Li Y, Wu Y, et al. (2021). Low carbon district heating in China in 2025- a district heating mode with low grade waste heat as heat source. Energy, 230: 120765.

    Google Scholar 

  • Generous MM, Qasem NAA, Zubair SM (2020). Exergy-based entropy-generation analysis of electrodialysis desalination systems. Energy Conversion and Management, 220: 113119.

    Google Scholar 

  • Goh PS, Kang HS, Ismail AF, et al. (2021). The hybridization of thermally-driven desalination processes: The state-of-the-art and opportunities. Desalination, 506: 115002.

    Google Scholar 

  • Goodarzi S, Jahanshahi Javaran E, Rahnama M, et al. (2019). Technoeconomic evaluation of a multi effect distillation system driven by low-temperature waste heat from exhaust flue gases. Desalination, 460: 64–80.

    Google Scholar 

  • Goričanec D, Pozeb V, Tomšič L, et al. (2014). Exploitation of the waste-heat from hydro power plants. Energy, 77: 220–225.

    Google Scholar 

  • Han B, Tang D, Wu Q (2017). The characters and influence on marine organism of thermal discharge from coastal power plant. Advances in Environmental Protection, 7(2): 110–114. (in Chinese)

    Google Scholar 

  • Harandi HB, Asadi A, Rahnama M, et al. (2021). Modeling and multi-objective optimization of integrated MED-TVC desalination system and gas power plant for waste heat harvesting. Computers & Chemical Engineering, 149: 107294.

    Google Scholar 

  • He C, Harden CP, Liu Y (2020). Comparison of water resources management between China and the United States. Geography and Sustainability, 1: 98–108.

    Google Scholar 

  • Hesari F, Salimnezhad F, Khoshgoftar Manesh MH, et al. (2021). A novel configuration for low-grade heat-driven desalination based on cascade MED. Energy, 229: 120657.

    Google Scholar 

  • Jamil MA, Zubair SM (2018). Effect of feed flow arrangement and number of evaporators on the performance of multi-effect mechanical vapor compression desalination systems. Desalination, 429: 76–87.

    Google Scholar 

  • Jebakumar JPP, Nandhagopal G, Babu BR, et al. (2018). Impact of coastal power plant cooling system on planktonic diversity of a polluted creek system. Marine Pollution Bulletin, 133: 378–391.

    Google Scholar 

  • Lee S, Park TS, Park YG, et al. (2020). Toward scale-up of seawater reverse osmosis (SWRO)-pressure retarded osmosis (PRO) hybrid system: A case study of a 240 m3/day pilot plant. Desalination, 491: 114429.

    Google Scholar 

  • Li Y, Fu L, Zhang S, et al. (2011). A new type of district heating system based on distributed absorption heat pumps. Energy, 36: 4570–4576.

    Google Scholar 

  • Li Y, Wang W, Ma Y, et al. (2018). Study of new cascade heating system with multi-heat sources based on exhausted steam waste heat utilization in power plant. Applied Thermal Engineering, 136: 475–483.

    Google Scholar 

  • Li Y, Pan W, Xia J, et al. (2019). Combined heat and water system for long-distance heat transportation. Energy, 172: 401–408.

    Google Scholar 

  • Lin J, Zou X, Huang F, et al. (2021a). Quantitative estimation of sea surface temperature increases resulting from the thermal discharge of coastal power plants in China. Marine Pollution Bulletin, 164: 112020.

    Google Scholar 

  • Lin S, Zhao H, Zhu L, et al. (2021b). Seawater desalination technology and engineering in China: A review. Desalination, 498: 114728.

    Google Scholar 

  • Ma S, Guo S, Zheng D, et al. (2021). Roadmap towards clean and low carbon heating to 2035: A provincial analysis in Northern China. Energy, 225: 120164.

    Google Scholar 

  • Manassaldi JI, Mussati MC, Scenna NJ, et al. (2021). Process optimization and revamping of combined-cycle heat and power plants integrated with thermal desalination processes. Energy, 233: 121131.

    Google Scholar 

  • Mendis T, Huang Z, Xu S (2020). Determination of economically optimised building integrated photovoltaic systems for utilisation on facades in the tropical climate: A case study of Colombo, Sri Lanka. Building Simulation, 13: 171–183.

    Google Scholar 

  • Narasimhan A, Kamal R, Almatrafi E (2022). Novel synergetic integration of supercritical carbon dioxide Brayton cycle and adsorption desalination. Energy, 238: 121844.

    Google Scholar 

  • Nassrullah H, Anis SF, Hashaikeh R, et al. (2020). Energy for desalination: A state-of-the-art review. Desalination, 491: 114569.

    Google Scholar 

  • Olkis C, Al-Hasni S, Brandani S, et al. (2021). Solar powered adsorption desalination for Northern and Southern Europe. Energy, 232: 120942.

    Google Scholar 

  • Pan W (2019). Seawater Desalination and combining heat and water systems for long-distance heat transportation. Master Thesis, Tsinghua University, China. (in Chinese)

    Google Scholar 

  • Panowski M, Zarzycki R, Kobyłecki R (2021). Conversion of steam power plant into cogeneration unit - Case study. Energy, 231: 120872.

    Google Scholar 

  • Park K, Kim DY, Jang YH, et al. (2020). Comprehensive analysis of a hybrid FO/crystallization/RO process for improving its economic feasibility to seawater desalination. Water Research, 171: 115426.

    Google Scholar 

  • Pietrasanta AM, Mussati SF, Aguirre PA, et al. (2022). Optimization of a multi-generation power, desalination, refrigeration and heating system. Energy, 238: 121737.

    Google Scholar 

  • Rahimi BJ, Chua HT (2017). Plate heat exchanger overall heat transfer coefficient. In: Low Grade Heat Driven Multi-Effect Distillation and Desalination. Amsterdam: Elsevier.

    Google Scholar 

  • Rahman S, Jafary T, Al-Mamun A, et al. (2021). Towards upscaling microbial desalination cell technology: A comprehensive review on current challenges and future prospects. Journal of Cleaner Production, 288: 125597.

    Google Scholar 

  • Rostamzadeh H (2021). A new pre-concentration scheme for brine treatment of MED-MVC desalination plants towards low-liquid discharge (LLD) with multiple self-superheating. Energy, 225: 120224.

    Google Scholar 

  • Shahabi MP, McHugh A, Ho G (2015). Environmental and economic assessment of beach well intake versus open intake for seawater reverse osmosis desalination. Desalination, 357: 259–266.

    Google Scholar 

  • Shahzad MW, Burhan M, Ang L, et al. (2017). Energy-water-environment nexus underpinning future desalination sustainability. Desalination, 413: 52–64.

    Google Scholar 

  • Shakib SE, Amidpour M, Boghrati M, et al. (2021). New approaches to low production cost and low emissions through hybrid MED-TVC+RO desalination system coupled to a gas turbine cycle. Journal of Cleaner Production, 295: 126402.

    Google Scholar 

  • Sharqawy MH, Lienhard V JH, Zubair SM (2011). On exergy calculations of seawater with applications in desalination systems. International Journal of Thermal Sciences, 50: 187–196.

    Google Scholar 

  • Shen S, Zhou S, Mou X, et al. (2014). Analysis of thermal loss in heat transfer process of large scale low temperature multi effect evaporation desalination unit. CIESC Journal, 65(09): 3366–3374. (in Chinese)

    Google Scholar 

  • Su Z, Zhang M, Xu P, et al. (2021). Opportunities and strategies for multigrade waste heat utilization in various industries: A recent review. Energy Conversion and Management, 229: 113769.

    Google Scholar 

  • Sun F, Fu L, Sun J, et al. (2014). A new waste heat district heating system with combined heat and power (CHP) based on ejector heat exchangers and absorption heat pumps. Energy, 69: 516–524.

    Google Scholar 

  • Tol Hİ (2020). Improved space-heating radiator model: Focus on setback operation, radiator over-dimensioning, and add-on fans. Building Simulation, 13: 317–334.

    Google Scholar 

  • Voutchkov N (2018). Energy use for membrane seawater desalination-current status and trends. Desalination, 431: 2–14.

    Google Scholar 

  • Wang J, Xia K, Chen W, et al. (2015). Research on heat recovery system of turbine exhaust steam using absorption heat pump for heating supply based on heating load characteristics. Energy Procedia, 75: 1502–1507.

    Google Scholar 

  • Wang Y, Zhang F, Zhang Y, et al. (2019). Chinese power-grid financial capacity based on transmission and distribution tariff policy: A system dynamics approach. Utilities Policy, 60: 100941.

    Google Scholar 

  • Wang X, Xu Z, Gou X (2020). Allocation of fresh water recourses in China with nested probabilistic-numerical linguistic information in multi-objective optimization. Knowledge-Based Systems, 188: 105014.

    Google Scholar 

  • Wang J, Sun C, Qi C, et al. (2021a). Promoting the performance of district heating from waste heat recovery in China: a general solving framework based on the two-stage branch evaluation method. Energy, 220: 119757.

    Google Scholar 

  • Wang R, Lu S, Zhai X, et al. (2021b). The energy performance and passive survivability of high thermal insulation buildings in future climate scenarios. Building Simulation, https://doi.org/10.1007/s12273-021-0818-3.

  • Wunder F, Enders S, Semiat R (2017). Numerical simulation of heat transfer in a horizontal falling film evaporator of multiple-effect distillation. Desalination, 401: 206–229.

    Google Scholar 

  • Xie X, Jiang Y (2015). The ideal process model for absorption heat pumps with real solution. Journal of Refrigeration, 36(1): 13–23. (in Chinese)

    Google Scholar 

  • Xia J, Zhu K, Jiang Y (2016). Method for integrating low-grade industrial waste heat into district heating network. Building Simulation, 9: 153–163.

    Google Scholar 

  • Xu ZY, Mao HC, Liu DS, et al. (2018). Waste heat recovery of power plant with large scale serial absorption heat pumps. Energy, 165: 1097–1105.

    Google Scholar 

  • Xu ZY, Gao JT, Mao HC, et al. (2020). Double-section absorption heat pump for the deep recovery of low-grade waste heat. Energy Conversion and Management, 220: 113072.

    Google Scholar 

  • Zhai C, Wu W (2021). Heat and mass transfer performance comparison of various absorbers/desorbers towards compact and efficient absorption heat pumps. International Journal of Refrigeration, 127: 203–220.

    Google Scholar 

  • Zhang Y, Xia J, Fang H, et al. (2019). Roadmap towards clean heating in 2035: Case study of Inner Mongolia, China. Energy, 189: 116152.

    Google Scholar 

  • Zhang H, Liu X, Liu Y, et al. (2021a). Energy and exergy analyses of a novel cogeneration system coupled with absorption heat pump and organic Rankine cycle based on a direct air cooling coal-fired power plant. Energy, 229: 120641.

    Google Scholar 

  • Zhang Y, Hao J, Ge Z, et al. (2021b). Optimal clean heating mode of the integrated electricity and heat energy system considering the comprehensive energy-carbon price. Energy, 231: 120919.

    Google Scholar 

  • Zhao S, Ge Z, He J, et al. (2017). A novel mechanism for exhaust steam waste heat recovery in combined heat and power unit. Applied Energy, 204: 596–606.

    Google Scholar 

  • Zheng W, Zhang Y, Xia J, et al. (2020). Cleaner heating in Northern China: potentials and regional balances. Resources, Conservation and Recycling, 160: 104897.

    Google Scholar 

  • Zhou S, Liu X, Bian Y, et al. (2020). Energy, exergy and exergoeconomic analysis of a combined cooling, desalination and power system. Energy Conversion and Management, 218: 113006.

    Google Scholar 

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Acknowledgements

This work was supported by the 13th Five-Year National Key Technology R&D Program of China (No. 2019YFE0193200) and the Natural Science Foundation of China (No. 51521005).

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Correspondence to Jianjun Xia.

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Yang, X., Liu, Z., Chen, J. et al. Optimization of heat source side technical scheme of combined heat and water system based on a coal-fired power plant. Build. Simul. 15, 1455–1473 (2022). https://doi.org/10.1007/s12273-021-0874-8

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  • DOI: https://doi.org/10.1007/s12273-021-0874-8

Keywords

  • waste heat of power plant
  • combined heat and water
  • seawater desalination
  • optimal case
  • thermal economic analysis