# US 11,306,952 B2 · Refrigeration cycle apparatus

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- Number: US 11,306,952 B2
- Document ID: US11306952B2
- Status: Granted
- Kind: B2
- Application number: 16/767,648
- Filed: 2017-12-06
- Published: 2020-09-24
- Granted: 2022-04-19
- Earliest claimed: 2017-12-06
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Hiroki Ishiyama
- Web page: https://patentgrep.com/patent/US11306952B2

## CPC

- F25B 31/004: {oil recirculating arrangements}
- F25B 43/006: {Accumulators}
- F25B 49/02: for compression type machines, plants or systems
- F25B 2400/01: Heaters
- F25B 2400/23: Separators
- F25B 2500/31: Low ambient temperatures
- F25B 2700/2105: Oil temperatures
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS

## Abstract

A refrigeration cycle apparatus includes a refrigerant circuit in which refrigerant circulates in the order of a compressor, an oil separator, a first heat exchanger, a decompressing apparatus, and a second heat exchanger and returns to the compressor. The refrigeration cycle apparatus further includes: an oil reservoir that stores refrigeration oil; a first pipe that connects the oil separator and the oil reservoir, the first pipe sends the refrigeration oil separated by the oil separator to the oil reservoir; a second pipe that connects the oil reservoir and a suction side of the compressor; a third pipe that connects the oil reservoir and the suction side of the compressor at a position lower than a position at which the second pipe is connected to the oil reservoir; and a heater that heats the refrigeration oil separated by the oil separator.

## Claims

### Claim 1

A refrigeration cycle apparatus comprising:
a refrigerant circuit in which refrigerant circulates in the order of a compressor, an oil separator, a first heat exchanger, a decompressing apparatus, and a second heat exchanger and returns to the compressor;
an oil reservoir configured to store refrigeration oil;
a first pipe that connects the oil separator and the oil reservoir, the first pipe being configured to send the refrigeration oil separated by the oil separator to the oil reservoir;
a second pipe that connects the oil reservoir and a suction side of the compressor;
a third pipe that connects the oil reservoir and the suction side of the compressor at a position lower than a position at which the second pipe is connected to the oil reservoir;
a heater installed at the first pipe and configured to heat, in the first pipe, the refrigeration oil separated by the oil separator;
a temperature sensor configured to detect a temperature of the oil reservoir; and
a controller configured to control the heater to heat the refrigeration oil when the temperature detected by the temperature sensor is lower than a defined temperature.

### Claim 2 (depends on 1)

The refrigeration cycle apparatus according to claim 1, further comprising a flow rate regulating valve provided at the third pipe.