Abstract
A proposed midterm substitute of R410A, mixture with 1924 GWP100 (Global Warming Potential over 100 years), is R32 (GWP100 = 677), which, although mildly flammable, is pure, relatively cheap, already available on the market, with different suppliers due to the absence of patents. Moreover, its thermo-physical properties are already well known. Increasingly stringent energy saving regulations are boosting the residential heat pump market, which typically requires reversible brazed plate heat exchangers to be used both as evaporators and condensers. This work reports an experimental analysis of the two refrigerants during flow boiling in brazed plate heat exchangers, varying the channel volumes. The number of plates of the heat exchangers ranges from 4 (1 refrigerant channel) to 120 (59 refrigerant channels in parallel). The heat transfer coefficient and the pressure drop have been measured for R410A and R32 at saturation temperature between 1.5 °C and 5.5 °C, outlet vapour superheating of 5 K, heat flux from 4 to 31 kW m−2, mass velocity from 8 to 87 kg m−2 s−1 and inlet channels vapour quality from 0.2 to 0.3. The number of plates affects the distribution of the liquid-vapour mixture in the channels and its effect is discussed by comparing the heat transfer coefficients. It is shown that the differences in performance between the two fluids increase with the mass velocity, suggesting the influence of a convective component on the heat transfer coefficient. This is further confirmed by comparing the data with the results of two different models from literature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.