Air conditioning apparatus

Patent metadata

Field	Value
Publication number	US-9829230-B2
Application number	US-201313780037-A
Country	US
Kind code	B2
Filing date	Feb 28, 2013
Priority date	Feb 28, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An air-conditioning apparatus has different two modes including a response detection diagnosis in which a control unit diagnoses a trouble of a component device during the trouble diagnosis operation based on presence or absence of a response from the operational state sensor when the mode has forcibly changed the device operation, and a performance detection diagnosis in which a trouble is detected by a detection value of the operational state sensor at a time when the operational state of the trouble diagnosis operation is stable, and the performance detection diagnosis is executed after the response detection diagnosis is executed.

First claim

The invention claimed is:

1. An air-conditioning apparatus comprising:
a refrigerant circuit in which a compressor, a heat source side heat exchanger, a use side pressure reducing mechanism, a use side heat exchanger are connected by a pipe such that a refrigerant circulates therearound;
at least one of a temperature sensor that detects a refrigerant temperature and a pressure sensor that detects a refrigerant pressure;
a controller control device that includes a diagnostic operation instruction unit that instructs execution of a trouble diagnosis operation for specifying a trouble of the air-conditioning apparatus, and a determination unit that determines presence or absence of the trouble; and
a unit control device including a control unit that controls each of a plurality of component devices of the refrigerant circuit during the trouble diagnosis operation, wherein
the control unit is configured to perform both of a response detection diagnosis mode and a performance detection diagnosis mode during the trouble diagnosis operation, the diagnosis modes including:
in the response detection diagnosis mode, the control unit forcibly changes an operation of at least one of the plurality of component devices and detects a trouble in a case where a change in a detection value of the at least one of the temperature sensor and the pressure sensor is within a predetermined range of value, or a magnitude of the change in the detection value is equal to or smaller than a threshold value, and
in the performance detection diagnosis mode, the control unit detects a trouble based on a detection value of the at least one of the temperature sensor and the pressure sensor in a case where an operational state of the refrigerant circuit in the trouble diagnosis operation is stable, wherein

the performance detection diagnosis mode is executed after the response detection diagnosis mode is executed, and
the control unit sets an operation frequency of the compressor in the performance detection diagnosis mode to be greater than an operation frequency of the compressor in the response detection diagnosis mode.

2. The air-conditioning apparatus of claim 1 , further comprising:
a compressor invertor that changes an operation frequency of the compressor;
a heat source side fan that blows air to the heat source side heat exchanger;
a fan motor that changes a rotation speed by driving the heat source side fan;
a solenoid valve provided in at least a part of the pipe; and
a memory unit that stores information on to which of a plurality of branching ports each of a plurality of the use side heat exchangers and the use side pressure reducing mechanisms, the plurality of use side heat exchangers and use side pressure reducing mechanisms being connected by piping in parallel through the respective branching ports, is connected, wherein
a trouble diagnosed by the response detection diagnosis mode is at least any one of sensor drop-off, pressure reducing mechanism lock, solenoid valve lock, a compressor inverter defect, a fan motor defect, and a branching port setting error, and
a trouble diagnosed by the performance detection diagnosis mode is at least any one of pipe clogging, compressor efficiency deterioration, heat exchanger contamination and insufficient amount of refrigerant.

3. The air-conditioning apparatus of claim 1 , wherein
the control unit
fixes the operation frequency of the compressor during the trouble diagnosis operation,
fixes a rotation speed of the heat source side fan during the trouble diagnosis operation based on an outdoor air temperature and the operation frequency of the compressor; and
performs control of an opening degree of the use side pressure reducing mechanism such that an operational state detected by the at least one of the temperature sensor and the pressure sensor takes a predetermined value.

4. The air-conditioning apparatus of claim 1 , wherein
the determination unit, by using
a degree of supercooling at a position in a range from the compressor to the use side pressure reducing mechanism and
an opening degree of at least one pressure reducing mechanism installed in the refrigerant circuit,

as at least one stability determination index for determining an operational state to be stable, determines that the operational state is stable where fluctuation of the at least one stability determination index is within a predetermined range of value, and executes the performance detection diagnosis mode.

5. The air-conditioning apparatus of claim 1 , further comprising:
a unit communication unit that outputs an abnormality signal representing an abnormal condition to outside, the unit communication unit being provided in the unit control device, and
an external communication unit that receives an output signal from the unit communication unit, the external communication unit being provided in the controller control device, wherein
the diagnostic operation instruction unit specifies a portion on which the trouble is diagnosed based on the abnormality signal.

6. The air-conditioning apparatus of claim 1 , wherein
the operation instruction unit repeatedly executes trouble diagnosis until the determination unit determines that there is no trouble in the response detection diagnosis mode or the performance detection diagnosis mode.

7. The air-conditioning apparatus of claim 1 , further comprising:
a liquid receiver installed in a suction side of the compressor;
a liquid level detection sensor installed in the liquid receiver, and detecting a liquid level in the liquid receiver, wherein
the determination unit, by using a liquid level detected by the liquid level detection sensor as at least one stability determination index for determining an operational state as stable, determines that the operational state is stable where the fluctuation of the at least one stability determination index is within a predetermined range of value, and executes the performance detection diagnosis mode.

8. The air-conditioning apparatus of claim 1 , wherein
the controller control device further comprises a display unit that displays presence or absence of the trouble regarding a diagnostic mode diagnosed in the trouble diagnosis operation.

9. The air-conditioning apparatus of claim 1 , wherein
the performance detection diagnosis mode detects the trouble based on the detection value of the at least one of the temperature sensor and the pressure sensor, when the operational state of the trouble diagnosis operation is determined to be returned to stable after execution of the response detection diagnosis mode.

10. The air-conditioning apparatus of claim 1 , wherein
the control unit is further configured to
perform the control of each of the plurality of component devices during the trouble diagnosis operation, responsive to receipt of an instruction from the controller control device that instructs the execution of the trouble diagnosis operation, and
perform both of the response detection diagnosis mode and the performance detection diagnosis mode during the trouble diagnosis operation, wherein the performance detection diagnosis mode is executed, and then the air-conditioning apparatus stands by until an operational state of the air-conditioning apparatus is stabilized, and then the response detection diagnosis mode is executed.

Assignees

• Tamaki Shogo
• Shinozaki Kazuyoshi
• Kasai Tomohiko
• Mitsubishi Electric Corp

Inventors

• Tamaki Shogo
• Shinozaki Kazuyoshi
• Kasai Tomohiko

Classifications

• F25B2313/02741

  using one four-way valve · CPC title

• F25B2313/0315

  Temperature sensors near the outdoor heat exchanger · CPC title

• F25B2313/0314

  Temperature sensors near the indoor heat exchanger · CPC title

• F25B2700/1931

  Discharge pressures · CPC title

• F25B2400/23

  Separators · CPC title