US 12,264,858 B2
Cooling system with oil return to accumulator
Shitong Zha, Snellville, GA (US)
Assigned to Heatcraft Refrigeration Products LLC, Stone Mountain, GA (US)
Filed by Heatcraft Refrigeration Products LLC, Stone Mountain, GA (US)
Filed on Feb. 13, 2024, as Appl. No. 18/440,567.
Application 18/440,567 is a continuation of application No. 16/803,306, filed on Feb. 27, 2020, granted, now 11,933,527.
Prior Publication US 2024/0183595 A1, Jun. 6, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. F25B 43/02 (2006.01); F25B 41/20 (2021.01); F25B 43/00 (2006.01)
CPC F25B 43/02 (2013.01) [F25B 41/20 (2021.01); F25B 43/006 (2013.01); F25B 2500/04 (2013.01); F25B 2600/2519 (2013.01); F25B 2700/03 (2013.01); F25B 2700/2103 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a flash tank configured to store a primary refrigerant;
a first low side heat exchanger;
an accumulator that comprises a U-shaped pipe having an end configured to receive the primary refrigerant, and wherein the U-shaped pipe comprises a hole located towards a bottom of the accumulator;
a first compressor;
a second compressor;
a first valve;
a first cooling system fluidly coupled to the first low side heat exchanger; and
a second valve associated with the first low side heat exchanger;
wherein during a first mode of operation:
the first and second valves are closed;
the first low side heat exchanger is configured to use the primary refrigerant from the flash tank to cool a secondary refrigerant;
the accumulator is configured to receive the primary refrigerant from the first low side heat exchanger;
the first cooling system is configured to receive the cooled secondary refrigerant;
the first compressor is configured to compress the primary refrigerant from the accumulator; and
the second compressor is configured to compress the primary refrigerant from the first compressor,
wherein during a second mode of operation:
the first valve is open and configured to direct the primary refrigerant from the first low side heat exchanger and an oil from the first low side heat exchanger to a first vessel; and
the second valve is closed,
wherein during a third mode of operation:
the first valve is closed; and
the second valve is open and directs the primary refrigerant from the first compressor to the first vessel, wherein the primary refrigerant from the first compressor pushes the oil in the first vessel to the accumulator, and wherein the oil collected at the bottom of the accumulator is sucked through the hole in the U-shaped pipe and directed to the first compressor.