Experimental Study on Flow Maldistribution and Performance of Carbon Dioxide Microchannel Evaporator

  • Jing LvEmail author
  • Guo Li
  • Tang fuyi Xu
  • Chenxi Hu
Conference paper
Part of the Environmental Science and Engineering book series (ESE)


The effects of three inlet parameters on flow distribution and performance of a microchannel evaporator are investigated experimentally. The three research factors are evaporation pressure, inlet mass flow rate and dryness. The configuration is made of brazed aluminum microchannel flat tubes with multi-louver fin structure using CO2 as the refrigerant. Those 19 parallel flat tubes are divided into 9 intervals, and 72 temperature measurement points are set. The unevenness standard deviation is adapted to evaluate the unevenness of each interval. It is found that mass flow rate has the greatest influence on the flow maldistribution for a CO2 microchannel evaporator, followed by inlet dryness and evaporation temperature. The position of the inlet header has a great influence on the flow maldistribution of the heat exchanger and its performance. For a CO2 microchannel evaporator, the unevenness of flow maldistribution is reduced when increasing the inlet dryness or decreasing the mass flow rate. Moreover, the inlet dryness has much greater impact on performance than the mass flow rate and evaporation temperature. The CO2 microchannel evaporator is more apt to uneven flow maldistribution when the load is large, which will seriously affect its performance under extreme conditions.


Microchannel evaporator Flow maldistribution Heat transfer distribution CO2 


  1. 1.
    Khan, M.G., Fartaj, A.: A review on micro-channel heat exchangers and potential applications. Int. J. Energy Res. 35(5), 553–582 (2011)CrossRefGoogle Scholar
  2. 2.
    Brix, W., et al.: Modelling distribution of evaporating CO2 in parallel minichannels. Int. J. Refrig 33(6), 1086–1094 (2010)CrossRefGoogle Scholar
  3. 3.
    Kandlikar, S.G.:A roadmap for implementing minichannels in refrigeration and air-conditioning systems current status and future directions. Heat Transf. Eng. 28, 953–985 (2005)CrossRefGoogle Scholar
  4. 4.
    Choi, J.M., et al. Effects of nonuniform refrigerant and air flow distribution on finned tube evaporator performance. In: International Congress of Refrigeration, pp. 1–8, Washington, D.C., USA (2003)Google Scholar
  5. 5.
    Agostinni, B., et al.: Friction factor and heat transfer coefficient of R134a liquid flow in mini-channels. Appl. Therm. Eng. 22(16), 1821–1834 (2002)CrossRefGoogle Scholar
  6. 6.
    Yoon, S.H., et al.: Characteristics of evaporative heat transfer and pressure drop of carbon dioxide and correlation development. Int. J. Refrig 25(2), 111–119 (2004)CrossRefGoogle Scholar
  7. 7.
    Pettersen, J.: TWo-phase flow pattern, heat transfer, and pressure drop in microchannel vaporization of CO2. ASHRAE Trans. (Symp.) 109 (1), 523–532 (2003)Google Scholar
  8. 8.
    Cheng, L., et al.: New flow boiling heat transfer model and flow pattern map for carbon dioxide evaporating inside horizontal tubes. Int. J. Heat Mass Transf. 49(21–22), 4082–4094 (2006)CrossRefGoogle Scholar
  9. 9.
    Oh, H.K., Son, C.H.: Flow boiling heat transfer and pressure drop characteristics of CO2 in horizontal tube of 4.55 mm inner diameter. Appl. Therm. Eng. 31(2), 163–152 (2011)CrossRefGoogle Scholar
  10. 10.
    Habib, M.A., et al.: Evaluation of flow maldistribution in air-cooled heat exchangers. Comput. Fluids 8(3), 655–690 (2009)Google Scholar
  11. 11.
    Ducoulombie, M., Colasson, S.: Carbon dioxide flow boiling in a single microchannel-partII:heat transfer. Exp. Thermal Fluid Sci. 35, 595–611 (2011)Google Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.School of Environment and ArchitectureUniversity of Shanghai for Science and TechnologyShanghaiChina

Personalised recommendations