Refrigeration cycle apparatus having foreign substance release control

Patent metadata

Field	Value
Publication number	US-11149999-B2
Application number	US-201716487699-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	May 15, 2017
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A refrigeration cycle apparatus includes a refrigerant circuit, a controller, a bypass pipe, a refrigerant cooler, a second expansion device, and a controller temperature sensor. In a case where a temperature measured by the controller temperature sensor is lower than or equal to a set temperature in a state where an opening degree of the second expansion device is controlled to an instruction opening degree that is lower than or equal to a set opening degree, the controller is configured to perform foreign substance release control where the controller is configured to increase the opening degree of the second expansion device and then is configured to return the opening degree of the second expansion device to the instruction opening degree.

First claim

The invention claimed is:

1. A refrigeration cycle apparatus, comprising:
a refrigerant circuit through which refrigerant circulates, the refrigerant circuit including a compressor, a heat-source-side heat exchanger, a first expansion device, and a load-side heat exchanger;
a bypass pipe branched from a pipe between the compressor and the first expansion device, and connected to a pipe connected to a suction port of the compressor;
a second expansion device provided in the bypass pipe, the second expansion device being configured to regulate a flow rate of the refrigerant flowing through the bypass pipe;
a refrigerant cooler through which the refrigerant flows, the refrigerant cooler being provided in the bypass pipe;
a controller including a processor and a memory, the controller being configured to control the compressor, the first expansion device, and the second expansion device, the controller being cooled by the refrigerant cooler; and
a controller temperature sensor configured to measure a temperature of the controller,
the controller being further configured to
in a case that both (i) the temperature measured by the controller temperature sensor is determined to be lower than or equal to a set temperature and (ii) an opening degree of the second expansion device is determined to be instructed to an instruction opening degree that is lower than or equal to a set opening degree,
determine that the second expansion device is clogged with a foreign substance, and perform a foreign substance release control to increase the opening degree of the second expansion device and then return the opening degree of the second expansion device to the instruction opening degree.

2. The refrigeration cycle apparatus of claim 1 , wherein, in a case where the temperature measured by the controller temperature sensor is lower than or equal to a set finishing temperature, the controller is configured to control the opening degree of the second expansion device to the instruction opening degree that is lower than or equal to the set opening degree.

3. The refrigeration cycle apparatus of claim 1 , wherein the instruction opening degree corresponds to a closed state.

4. The refrigeration cycle apparatus of claim 1 , wherein, in the foreign substance release control, the controller is configured to bring the opening degree of the second expansion device into a fully open state, and then is configured to return the opening degree of the second expansion device to the instruction opening degree.

5. The refrigeration cycle apparatus of claim 1 , wherein the set temperature is defined by a temperature at which dew condenses on the controller.

6. The refrigeration cycle apparatus of claim 1 , wherein the controller is configured to temporarily stop an operation of the compressor in a case where the temperature measured by the controller temperature sensor is lower than or equal to the set temperature after the controller performs the foreign substance release control.

7. The refrigeration cycle apparatus of claim 6 , wherein, in a case where the number of times that the operation of the compressor is temporarily stopped is less than a set number of times, the controller is configured restart the compressor after the controller temporarily stops the compressor.

8. The refrigeration cycle apparatus of claim 7 further comprising
a notification lamp or monitor configured to notify emergency stop, wherein
the controller is configured to perform emergency stop of the operation of the compressor in a case where the number of times of temporary stopping is greater than or equal to the set number of times, and then is configured to output, to the notification lamp or monitor, information that the controller performs the emergency stop.

Assignees

• Mitsubishi Electric Corp

Inventors

• Koike Takanori
• Morimoto Osamu
• Okano Hiroyuki

Classifications

• Y02B30/70

  Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating · CPC title

• F25B41/34 Primary

  with the valve member being actuated by electric means, e.g. by piezoelectric actuators · CPC title

• F25B41/385

  Dispositions with two or more expansion means arranged in parallel on a refrigerant line leading to the same evaporator · CPC title

• F25B49/022 Primary

  Compressor control arrangements · CPC title

• F25B13/00

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title