EcoRenovator - View Single Post - Propane (R-290) for heat pumps?

buffalobillpatrick · 11-16-14, 10:28 AM

Jeff5May, your post quoting from that study:

"...the high solubility of mineral oils in propane could represent a problem, especially for applications such as heat pumps displaying high suction pressures... the experimental results reported in the present work can therefore be explained by means of the strong influence that the propane solubility could have on the sealing effect of the lubricant between piston and cylinder... the solubility is shown to strongly decrease by increasing the superheating; as a consequence, the viscosity of the oil strongly increases with superheating until reaching a maximum at around 30-40K superheating... the suction superheat would have a positive influence on the volumetric efficiency."

Also in that study MO ISO32 viscosity is only 58% (22/38) of POE ISO32 viscosity at same testing conditions.

So why use MO?

11-16-14, 10:28 AM	#263
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Jeff5May, your post quoting from that study: "...the high solubility of mineral oils in propane could represent a problem, especially for applications such as heat pumps displaying high suction pressures... the experimental results reported in the present work can therefore be explained by means of the strong influence that the propane solubility could have on the sealing effect of the lubricant between piston and cylinder... the solubility is shown to strongly decrease by increasing the superheating; as a consequence, the viscosity of the oil strongly increases with superheating until reaching a maximum at around 30-40K superheating... the suction superheat would have a positive influence on the volumetric efficiency." Also in that study MO ISO32 viscosity is only 58% (22/38) of POE ISO32 viscosity at same testing conditions. So why use MO?