Turbomachinery

When the refrigerant for refrigerator was switched from CFC12 to HFC134a for the preservation of the ozone layer, the refrigerant oil also had to be changed from mineral oil to ester oil for securing miscibility. Ensuring efficiency and lubricity has surely and steadily advanced but a trouble of capillary tube clogging has occurred. The blockage of a capillary tube is identified to have been caused by the mold lubricant of the plastic components adopted inside the compressor, which led the sludge accumulation mechanism to elucidation. On the basis of this outcome it came to be possible to prevent the blockage of capillary tube perfectly.

View full abstract

Show abstractHide abstract

In the previous paper, we indicated that characteristics of jet pumps could be expressed generally by using the same definition of pressure ratio and flow rate. We offered two non-dimensional parameters concerned with the volume of mixing zone and exhibited how those parameters influenced on pressure ratio and flow rate at maximum efficiency.
This paper studied the influences of non-dimensional parameters on pressure ratio and flow rate at maximum value by a similar method. In the case at maximum value, we obtained also the same results as those of the case at maximum efficiency.
Furthermore, we analyzed the relations between pressure ratio and flow rate at maximum efficiency by assuming an exponential relation between them and indicated that they were almost the half value of those at maximum value respectively.
Experimental and analytical results showed reasonable agreement. These results must be important for designing of jet pump.

View full abstract

Download PDF (404K)

Register with J-STAGE for free!