It's vital to optimise the refrigerant charge for refrigeration and air-conditioning units. The attached are charging curves of a typical air cooler R290 unit with 5mm OD tube air coils based on modelling with RefrigLab cloud eTools (www.refriglab.com):
Fig(a): Both COP and cooling capacity are maximised with R290 charge of 140-148g. Refrigerant R290 entering into TEV is subcooled (SC>0, quality Xinlet=0, no bubbling) with charge >=130g.
Fig(b): Condensing and evaporating temperatures increase with the charging while suction vapour superheat decreases first during the undercharged period and increases slowly during the later overcharged process.
Fig(c): Compressor stores nearly half (42%-53%) of total R290 charge during the undercharged but condenser coil holds the largest during the last overcharged stage.
Any suggestions or comments on the modelling?
This post for discussion is a follow-up to my previous ones at LinkedIn:
https://lnkd.in/g68uaJW
https://lnkd.in/g4kRSq8
https://lnkd.in/gPbb8E7
https://lnkd.in/eBNvrYF