Air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-9933193-B2
Application number	US-201515122252-A
Country	US
Kind code	B2
Filing date	Apr 2, 2015
Priority date	Apr 4, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

An air-conditioning apparatus includes a refrigeration cycle charged with non-azeotropic refrigerant mixture and refrigerating machine oil. A suction pipe which is a refrigerant pipe connecting between a suction port of a compressor and an accumulator has an end portion on the side of the accumulator extending into the accumulator. In addition, the suction pipe of the air-conditioning apparatus includes an oil return hole formed in a portion of the suction pipe located inside the accumulator at a position higher than a central portion of the accumulator. A controller of the air-conditioning apparatus controls an opening degree of a pressure reducing device so as to make quality of refrigerant flowing into the accumulator less than 1.

First claim

The invention claimed is:

1. An air-conditioning apparatus comprising:
a refrigeration cycle in which a compressor, a condenser, a pressure reducing device, an evaporator and an accumulator are connected via a refrigerant pipe, the refrigeration cycle being charged with a non-azeotropic refrigerant mixture and refrigerating machine oil;
a controller that controls an opening degree of the pressure reducing device;
a suction pipe, which is the refrigerant pipe connecting between a suction port of the compressor and the accumulator, having an end portion on a side of the accumulator extending into the accumulator;
a first refrigerant temperature sensor that detects a temperature of refrigerant flowing through the evaporator; and
a second refrigerant temperature sensor that detects a temperature of refrigerant flowing into the accumulator,
wherein the suction pipe includes an oil return hole formed in a portion of the suction pipe located inside the accumulator, at a position higher than a central portion of the accumulator, and
wherein the controller is configured to control the opening degree of the pressure reducing device so as to make a value obtained by subtracting a value detected by the first refrigerant temperature sensor from a value detected by the second refrigerant temperature sensor less than 0 degrees Celsius and to make quality of refrigerant flowing into the accumulator less than 1.

2. The air-conditioning apparatus of claim 1 ,
wherein the non-azeotropic refrigerant mixture is a mixture of HFO-1234yf or HFO-1234ze and HFC-R32.

Assignees

• Mitsubishi Electric Corp

Inventors

• Yamamoto Kazuhide

Classifications

• F25B2700/2117

  of an evaporator · CPC title

• F25B2400/121

  using R1234 · CPC title

• F25B49/02 Primary

  for compression type machines, plants or systems · CPC title

• F25B2700/21152

  at the discharge side of the compressor · CPC title

• F25B2313/02741

  using one four-way valve · CPC title