IDEAS home Printed from https://ideas.repec.org/a/gam/jeners/v17y2024i10p2432-d1397749.html
   My bibliography  Save this article

Viability of an Open-Loop Heat Pump Drying System in South African Climatic Conditions

Author

Listed:
  • Solomzi Marco Ngalonkulu

    (Department of Mechanical and Mechatronics Engineering, Tshwane University of Technology, Staatsartillerie Road, Pretoria West, Pretoria 0183, South Africa)

  • Zhongjie Huan

    (Department of Mechanical and Mechatronics Engineering, Tshwane University of Technology, Staatsartillerie Road, Pretoria West, Pretoria 0183, South Africa)

Abstract

Drying agricultural produce consumes a considerable amount of energy. As an energy-efficient system, a heat pump can improve the energy efficiency of the drying process and hence reduce the energy consumption, especially in South Africa, where both sub-tropical and temperate weather conditions dominate. The objective of this research is to experimentally investigate the impacts of weather conditions on the operational conditions and thermal performance of an open-loop air-source heat pump drying system. The experimental investigation was conducted in a climate chamber where the climate conditions were simulated from −10 °C to 20 °C with an interval of 10 °C for the typical temperature range of the harvesting season in South Africa. The findings indicate that ambient temperatures have a significant impact on both the operating conditions and thermal performance of an open-loop heat pump system; the change in ambient temperatures from −10 °C to 20 °C leads to a 141.6% improvement in the suction pressure, a 214.2% increase in the discharge pressure, and 30.1% increase in the compression ratio, as well as a consequent increase of 130.6% in the refrigerant mass flow rate (from 0.0067 to 0.0155 kg/s), resulting in a corresponding increase in the coefficient of performance (COP) of the heat pump drying system by about 42.1%. Therefore, this study suggests that, while using an open-loop air-source heat pump drying system utilising R134a refrigerant is feasible in South Africa, it may be practically limited to regions with warm climates or during warmer seasons.

Suggested Citation

  • Solomzi Marco Ngalonkulu & Zhongjie Huan, 2024. "Viability of an Open-Loop Heat Pump Drying System in South African Climatic Conditions," Energies, MDPI, vol. 17(10), pages 1-14, May.
  • Handle: RePEc:gam:jeners:v:17:y:2024:i:10:p:2432-:d:1397749
    as

    Download full text from publisher

    File URL: https://www.mdpi.com/1996-1073/17/10/2432/pdf
    Download Restriction: no

    File URL: https://www.mdpi.com/1996-1073/17/10/2432/
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Hamid, Khalid & Sajjad, Uzair & Yang, Kai Shing & Wu, Shih-Kuo & Wang, Chi-Chuan, 2022. "Assessment of an energy efficient closed loop heat pump dryer for high moisture contents materials: An experimental investigation and AI based modelling," Energy, Elsevier, vol. 238(PB).
    2. Fan, Hongming & Shao, Shuangquan & Tian, Changqing, 2014. "Performance investigation on a multi-unit heat pump for simultaneous temperature and humidity control," Applied Energy, Elsevier, vol. 113(C), pages 883-890.
    3. Carroll, P. & Chesser, M. & Lyons, P., 2020. "Air Source Heat Pumps field studies: A systematic literature review," Renewable and Sustainable Energy Reviews, Elsevier, vol. 134(C).
    4. Tunckal, Cüneyt & Doymaz, İbrahim, 2020. "Performance analysis and mathematical modelling of banana slices in a heat pump drying system," Renewable Energy, Elsevier, vol. 150(C), pages 918-923.
    5. Chua, K.J. & Chou, S.K. & Yang, W.M., 2010. "Advances in heat pump systems: A review," Applied Energy, Elsevier, vol. 87(12), pages 3611-3624, December.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Giovanni Murano & Francesca Caffari & Nicolandrea Calabrese, 2024. "Energy Potential of Existing Reversible Air-to-Air Heat Pumps for Residential Heating," Sustainability, MDPI, vol. 16(14), pages 1-23, July.
    2. Nizetic, S. & Coko, D. & Marasovic, I., 2014. "Experimental study on a hybrid energy system with small- and medium-scale applications for mild climates," Energy, Elsevier, vol. 75(C), pages 379-389.
    3. Yu, Xinyi & Wu, Weidong & Wang, Jing & Jin, Yunfei & Li, Zhenbo, 2022. "Experimental study on effect of drying air supply temperature on performance of a quasi-two-stage closed loop heat pump drying system for lentinus edodes," Renewable Energy, Elsevier, vol. 201(P1), pages 1038-1049.
    4. Kofi Owura Amoabeng & Jong Min Choi, 2018. "Performance Analysis on the Optimum Control of a Calorimeter with a Heat Recovery Unit for a Heat Pump," Energies, MDPI, vol. 11(9), pages 1-20, August.
    5. Konrad, Mary Elizabeth & MacDonald, Brendan D., 2023. "Cold climate air source heat pumps: Industry progress and thermodynamic analysis of market-available residential units," Renewable and Sustainable Energy Reviews, Elsevier, vol. 188(C).
    6. Sun, Fangtian & Fu, Lin & Sun, Jian & Zhang, Shigang, 2014. "A new waste heat district heating system with combined heat and power (CHP) based on ejector heat exchangers and absorption heat pumps," Energy, Elsevier, vol. 69(C), pages 516-524.
    7. Peacock, Malcolm & Fragaki, Aikaterini & Matuszewski, Bogdan J, 2023. "The impact of heat electrification on the seasonal and interannual electricity demand of Great Britain," Applied Energy, Elsevier, vol. 337(C).
    8. Deymi-Dashtebayaz, Mahdi & Kheir Abadi, Majid & Asadi, Mostafa & Khutornaya, Julia & Sergienko, Olga, 2024. "Investigation of a new solar-wind energy-based heat pump dryer for food waste drying based on different weather conditions," Energy, Elsevier, vol. 290(C).
    9. Fredrik Skaug Fadnes & Reyhaneh Banihabib & Mohsen Assadi, 2023. "Using Artificial Neural Networks to Gather Intelligence on a Fully Operational Heat Pump System in an Existing Building Cluster," Energies, MDPI, vol. 16(9), pages 1-33, May.
    10. Blarke, Morten B., 2012. "Towards an intermittency-friendly energy system: Comparing electric boilers and heat pumps in distributed cogeneration," Applied Energy, Elsevier, vol. 91(1), pages 349-365.
    11. Jie, Ji & Jingyong, Cai & Wenzhu, Huang & Yan, Feng, 2015. "Experimental study on the performance of solar-assisted multi-functional heat pump based on enthalpy difference lab with solar simulator," Renewable Energy, Elsevier, vol. 75(C), pages 381-388.
    12. O'Hegarty, R. & Kinnane, O. & Lennon, D. & Colclough, S., 2022. "Air-to-water heat pumps: Review and analysis of the performance gap between in-use and product rated performance," Renewable and Sustainable Energy Reviews, Elsevier, vol. 155(C).
    13. Waheed, M.A. & Oni, A.O. & Adejuyigbe, S.B. & Adewumi, B.A. & Fadare, D.A., 2014. "Performance enhancement of vapor recompression heat pump," Applied Energy, Elsevier, vol. 114(C), pages 69-79.
    14. Luo, Yimo & Chen, Yi & Yang, Hongxing & Wang, Yuanhao, 2017. "Study on an internally-cooled liquid desiccant dehumidifier with CFD model," Applied Energy, Elsevier, vol. 194(C), pages 399-409.
    15. Wang, Wenyi & Zhao, Zhongfan & Zhou, Qun & Qiao, Yiyuan & Cao, Feng, 2021. "Model predictive control for the operation of a transcritical CO2 air source heat pump water heater," Applied Energy, Elsevier, vol. 300(C).
    16. Roberto Bruno & Francesco Nicoletti & Giorgio Cuconati & Stefania Perrella & Daniela Cirone, 2020. "Performance Indexes of an Air-Water Heat Pump Versus the Capacity Ratio: Analysis by Means of Experimental Data," Energies, MDPI, vol. 13(13), pages 1-19, July.
    17. Joshua Adeniyi Depiver & Sabuj Mallik, 2023. "An Empirical Study on Convective Drying of Ginger Rhizomes Leveraging Environmental Stress Chambers and Linear Heat Conduction Methodology," Agriculture, MDPI, vol. 13(7), pages 1-28, June.
    18. Sun, Fangtian & Fu, Lin & Sun, Jian & Zhang, Shigang, 2014. "A new ejector heat exchanger based on an ejector heat pump and a water-to-water heat exchanger," Applied Energy, Elsevier, vol. 121(C), pages 245-251.
    19. Nguyen, Hiep V. & Law, Ying Lam E. & Alavy, Masih & Walsh, Philip R. & Leong, Wey H. & Dworkin, Seth B., 2014. "An analysis of the factors affecting hybrid ground-source heat pump installation potential in North America," Applied Energy, Elsevier, vol. 125(C), pages 28-38.
    20. Ángel M. Costa & Rebeca Bouzón & Diego Vergara & José A. Orosa, 2019. "Eco-friendly Pressure Drop Dehumidifier: An Experimental and Numerical Analysis," Sustainability, MDPI, vol. 11(7), pages 1-17, April.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:gam:jeners:v:17:y:2024:i:10:p:2432-:d:1397749. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: MDPI Indexing Manager (email available below). General contact details of provider: https://www.mdpi.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.