HEAT PUMP

• US 20180051704A1
• Filed: 03/11/2016
• Published: 02/22/2018
• Est. Priority Date: 03/17/2015
• Status: Active Grant

• Current Assignee: Yanmar Power Technology Co., Ltd.
• Original Assignee: Yanmar Company Limited (Yanmar Holdings Co., Ltd.)
• Inventors: KIHARA, Hirotoshi, OTA, Keisuke, AIKAWA, Terunori, NOBUHARA, Hirohiko, NAKAMURA, Hirotaka
• Granted Patent: US 10,641,530 B2
• Time in Patent Office: Days
• CPC Class Codes: F04D 27/009 by bleeding, by passing or recycling fluid
• CPC Class Codes: F25B 1/00 Compression machines, plants or systems with non-reversible cycle F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence
• CPC Class Codes: F25B 2500/27 characterised by the stop of the refrigeration cycle
• CPC Class Codes: F25B 2600/025 by controlling speed
• CPC Class Codes: F25B 2600/2519 On-off valves
• CPC Class Codes: F25B 2700/1932 Oil pressures
• CPC Class Codes: F25B 31/004 oil recirculating arrangements
• CPC Class Codes: F25B 41/37 Capillary tubes
• CPC Class Codes: F25B 43/02 for separating lubricants from the refrigerant
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems

Abstract

An exemplary heat pump (10) includes: a compressor (16A, 16B) that discharges refrigerant; an oil separator (30) that separates oil from the refrigerant discharged from the compressor; an oil return channel (80) that returns the oil separated by the oil separator to the compressor; a pressure sensor (86A, 86B) that detects a pressure in the oil return channel; a first pressure loss member (84A, 84B) and a second pressure loss member (88A, 88B) disposed in portions of the oil return channel at an oil separator side and a compressor side relative to the pressure sensor; and a control device that increases an output of the compressor in a case where a pressure detected by the pressure sensor exceeds a suction pressure of the compressor and less than a discharge pressure of the compressor.

Claims

1. A heat pump comprising:

a compressor configured to compress refrigerant and discharge the compressed refrigerant;

an oil separator configured to separate oil from the compressed refrigerant discharged from the compressor;

an oil return channel configured to return the oil separated by the oil separator to the compressor;

a pressure sensor configured to detect a pressure at a location in the oil return channel;

first and second pressure loss members disposed in or defining portions of the oil return channel, wherein;

the first pressure loss member is upstream of the location; and

the second pressure loss member is downstream of the location;

a shut-off valve configured to selectively block fluid communication between the oil separator and the first pressure loss member; and

a control device configured to control the compressor to increase an output of the compressor when a pressure detected by the pressure sensor exceeds a suction pressure of the compressor and is less than a discharge pressure of the compressor.