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Comparative Exergy Analysis and Environmental Impact of a Dairy Plant Integrated with a Transcritical Heat Pump System: A Feasibility of Throttle Valve, Expander, and an Ejector as Expansion Devices

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Abstract

The present investigation aims to reuse the heat rejected in the condenser unit of an NH3-based dairy plant to preheat the groundwater used for pasteurization of milk. A detailed thermodynamic analysis (both energetic and exergetic) of the refrigeration unit of an existing dairy plant and the boiler unit used for pasteurization is carried out in the current work. The chemical exergy of the air–water vapour mixture and the standard Indian coal is considered while analysing the evaporative condenser and the boiler unit. Cascading of the existing system with a transcritical vapour compression cycle is proposed to effectively use the heat rejected by the combined system to preheat the boiler feed water. A comparative study for different modifications, such as the inclusion of an expander and an ejector in place of the throttle valve in the top cycle of the proposed cascade system, is carried out. Additionally, the cascade systems are being analysed for two different refrigerants, i.e., CO2 and N2O. The study demonstrates that the cascade system with an expander employing N2O as the refrigerant gives the maximum benefit in terms of saving of $16.5 to $21.5 per day, 1.5 to 2% reduction in total CO2 emission, and a 2.5% reduction in total exergy destruction, as compared to the existing NH3 system.

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Abbreviations

c p :

Specific heat at constant pressure, kJ/kg K

\(\dot{I}\) :

Exergy destruction rate/Irreversibility rate, kW

\(\dot{m}\) :

Mass flow rate, kg/s

\(\dot{Q}\) :

Heat transfer rate, kW

\(\dot{W}\) :

Power, kW

h :

Enthalpy, kJ/kg

h fg :

Latent heat of vaporization, kJ/ kg

s :

Entropy, kJ/kg K

u :

Velocity, m/s

v :

Specific volume, m3/kg

x :

Dryness fraction

\(\alpha_{{{\text{stoi}}}}\) :

Stoichiometric air requirement, kg/kg

\(\Phi\) :

Non flow exergy, kJ/kg

\(\varphi_{{{\text{dry}}}}\) :

Ratio of standard chemical exergy to NCV of fossil fuel

\(\eta\) :

Efficiency

\(\eta_{{{\text{II}}}}\) :

Second law efficiency

\(\phi\) :

Relative humidity

\(\omega\) :

Specific humidity, kgw/kga

\({\varepsilon }_{\mathrm{s}}^{0}\) :

Standard exergy of sulphur, kJ/kg

∆:

Difference

µ :

Entrainment ratio

ψ :

Flow exergy, kJ/kg

amb:

Ambient

CC:

Cascade condenser

com:

Compressor

cond:

Condenser

CT:

Compressor of top cycle

diff:

Diffuser

EV:

Expansion valve

evp:

Evaporator

EX:

Expander

GC:

Gas cooler

HP:

High pressure

in:

Inflow

LP:

Low pressure

mix:

Mixing zone

noz:

Nozzle

out:

Outflow

p:

Primary

s:

Secondary

sat:

Saturated

v:

Vapour

APH:

Air preheater

DBT:

Dry bulb temperature

EVC:

Evaporative condenser

GW:

Groundwater

NCV:

Net calorific value

WPH:

Water preheater

WBT:

Wet bulb temperature

References

  1. http://www.fao.org/india/fao-in-india/india-at-a-%20glance/en/

  2. Singh, S.; Dasgupta, M. S.: A trans-critical CO2 heat pump system for waste heat utilization in warm weather condition applied to a milk refrigeration plant. In: Proceedings of 16th International Refrigeration and Air Conditioning Conference at Purdue, July 11–14, 2016 (2016)

  3. Liu, Y.; Groll, E.A.; Yazawa, K.; Kurtulus, O.: Energy-saving performance and economics of CO2 and NH3 heat pumps with simultaneous cooling and heating applications in food processing: Case studies. Int. J. Refrig. 73, 111–124 (2017)

    Article  Google Scholar 

  4. Çomakli, Ö.; Yüksel, B.; Kara, Y.A.; Çaǧlar, A.; Tülek, Y.: Heat pump utilization in milk pasteurization. Energy Convers. Manage. 35(2), 91–96 (1994)

    Article  Google Scholar 

  5. Singh, S.; Dasgupta, M.S.: CO2 heat pump for waste heat recovery and utilization in dairy industry with ammonia based refrigeration. Int. J. Refrig. 78, 108–120 (2017)

    Article  Google Scholar 

  6. Ahammed, M.E.; Bhattacharyya, S.; Ramgopal, M.: Thermodynamic design and simulation of a CO2 based transcritical vapour compression refrigeration system with an ejector. Int. J. Refrig. 45, 177–188 (2014)

    Article  Google Scholar 

  7. Ahammed, M.E.; Bhattacharyya, S.; Ramgopal, M.: Analysis of CO2 based refrigeration systems with and without ejector for simultaneous pasteurization and chilling of milk. Int. J. Refrig. 95, 61–72 (2018)

    Article  Google Scholar 

  8. Liu, J.; Liu, Y.; Yu, J.: Performance analysis of a modified dual-ejector and dual-evaporator transcritical CO2 refrigeration cycle for supermarket application. Int. J. Refrig. 131, 109–118 (2021)

    Article  Google Scholar 

  9. Vutukuru, R.; Pegallapati, A.S.; Maddali, R.: Thermodynamic studies on a solar assisted transcritical CO2 based tri-generation system with an ejector for dairy applications. Int. J. Refrig. 108, 113–123 (2019)

    Article  Google Scholar 

  10. Deng, J.Q.; Jiang, P.X.; Lu, T.; Lu, W.: Particular characteristics of transcritical CO2 refrigeration cycle with an ejector. Appl. Therm. Eng. 27(2–3), 381–388 (2007)

    Article  Google Scholar 

  11. Hajidavalloo, E.; Eghtedari, H.: Performance improvement of air-cooled refrigeration system by using evaporatively cooled air condenser. Int. J. Refrig. 33(5), 982–988 (2010)

    Article  Google Scholar 

  12. Kruse, H.; Rüssmann, H.: The natural fluid nitrous oxide—an option as substitute for low temperature synthetic refrigerants. Int. J. Refrig. 29(5), 799–806 (2006)

    Article  Google Scholar 

  13. Kauf, F.: Determination of the optimum high pressure for transcritical CO2-refrigeration cycles. Int. J. Therm. Sci. 38(4), 325–330 (1999)

    Article  Google Scholar 

  14. Gautam; Kumar, G.; Sahoo, S.: Performance improvement and comparisons of CO2 based adsorption cooling system using modified cycles employing various adsorbents: a comprehensive study of subcritical and transcritical cycles. Int. J. Refrig. 112, 136–154 (2020)

  15. Gautam; Sahoo, S.: A Comprehensive thermodynamic analysis and performance evaluation of a transcritical ejector expansion CO2 adsorption refrigeration system integrated with thermoelectric sub-cooler. J. Supercrit. Fluids 182, 105517 (2022)

  16. Fernandez, N.; Hwang, Y.; Radermacher, R.: Comparison of CO2 heat pump water heater performance with baseline cycle and two high COP cycles. Int. J. Refrig. 33(3), 635–644 (2010)

    Article  Google Scholar 

  17. Sarkar, J.; Bhattacharyya, S.; Gopal, M.R.: Optimization of a transcritical CO2 heat pump cycle for simultaneous cooling and heating applications. Int. J. Refrig. 27(8), 830–838 (2004)

    Article  Google Scholar 

  18. Tamura, T.; Yakumaru, Y.; Nishiwaki, F.: Experimental study on automotive cooling and heating air conditioning system using CO2 as a refrigerant. Int. J. Refrig. 28(8), 1302–1307 (2005)

    Article  Google Scholar 

  19. Yu, B.; Yang, J.; Wang, D.; Shi, J.; Chen, J.: An updated review of recent advances on modified technologies in transcritical CO2 refrigeration cycle. Energy 189, 116147 (2019)

    Article  Google Scholar 

  20. Dasi, K.; Singh, S.; Guruchethan, A.M.; Maiya, M.P.; Hafner, A.; Banasiak, K.; Neksa, P.: Performance evaluation of ejector based CO2 system for simultaneous heating and cooling application in an Indian dairy industry. Therm. Sci. Eng. Progress 20, 100626 (2020)

    Article  Google Scholar 

  21. Lata, M.; Gupta, D.K.: Simulation and performance evaluation of trans-critical CO2 refrigeration system with modified evaporative cooled finned tube gas cooler in Indian context. Appl. Therm. Eng. 186, 116500 (2021)

    Article  Google Scholar 

  22. Liu, Y.; Groll, E.A.; Yazawa, K.; Kurtulus, O.: Theoretical analysis of energy-saving performance and economics of CO2 and NH3 heat pumps with simultaneous cooling and heating applications in food processing. Int. J. Refrig. 65, 129–141 (2016)

    Article  Google Scholar 

  23. Ozyurt, O.; Comakli, O.; Yilmaz, M.E.H.M.E.T.; Karslı, S.: Heat pump use in milk pasteurization: an energy analysis. Int. J. Energy Res. 28(9), 833–846 (2004)

    Article  Google Scholar 

  24. Vidal, M.; Martin, L.; Martin, M.: Can exergy be a useful tool for the dairy industry. In: 24th European Symposium Computer Aided Process Engineering—ESCAPE, at Budapest, Hungary, June 15–18, 2014, Vol. 24, pp. 1603–1608. (2014)

  25. Yildirim, N.; Genc, S.: Energy and exergy analysis of a milk powder production system. Energy Convers. Manage. 149, 698–705 (2017)

    Article  Google Scholar 

  26. Nemati, A.; Nami, H.; Yari, M.: A comparison of refrigerants in a two-stage ejector-expansion transcritical refrigeration cycle based on exergoeconomic and environmental analysis. Int. J. Refrig. 84, 139–150 (2017)

    Article  Google Scholar 

  27. Bejan, A.: Advanced Engineering Thermodynamics. John Wiley & Sons, Hoboken (2016)

    Book  Google Scholar 

  28. Shijaz, H.; Attada, Y.; Patnaikuni, V.S.; Vooradi, R.; Anne, S.B.: Analysis of integrated gasification combined cycle power plant incorporating chemical looping combustion for environment-friendly utilization of Indian coal. Energy Convers. Manage. 151, 414–425 (2017)

    Article  Google Scholar 

  29. Kotas, T.J.: The Exergy Method of Thermal Plant Analysis. Elsevier, Amsterdam (2013)

    Google Scholar 

  30. Li, D.; Groll, E.A.: Transcritical CO2 refrigeration cycle with ejector-expansion device. Int. J. Refrig. 28(5), 766–773 (2005)

    Article  Google Scholar 

  31. Keenan, J.H.; Neumann, E.P.; Lustwerk, F.: An investigation of ejector design by analysis and experiment. J. Appl. Mech. 17(3), 299–309 (1950)

    Article  Google Scholar 

  32. Robinson, D.M.; Groll, E.A.: Efficiencies of transcritical CO2 cycles with and without an expansion turbine: rendement de cycles transcritiques au CO2 avec et sans turbine d’expansion. Int. J. Refrig. 21(7), 577–589 (1998)

    Article  Google Scholar 

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Acknowledgements

The authors would like to acknowledge the Department of Science and Technology (Science and Engineering Research Board), Govt. of India [Grant No. ECR/2018/000141] for financial assistance provided to carry out the present research work.

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Authors and Affiliations

  1. Non-Conventional Refrigeration & Energy Storage Laboratory, Department of Mechanical Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004, India

    Biswajit Gorai, Satyabrata Sahoo &  Gautam

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  1. Biswajit Gorai
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Gorai, B., Sahoo, S. & Gautam Comparative Exergy Analysis and Environmental Impact of a Dairy Plant Integrated with a Transcritical Heat Pump System: A Feasibility of Throttle Valve, Expander, and an Ejector as Expansion Devices. Arab J Sci Eng 48, 3503–3521 (2023). https://doi.org/10.1007/s13369-022-07147-z

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