Air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-11802701-B2
Application number	US-201817260307-A
Country	US
Kind code	B2
Filing date	Sep 21, 2018
Priority date	Sep 21, 2018
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

An air-conditioning apparatus includes: an outdoor unit including a compressor that compresses and discharges refrigerant to a refrigerant circuit; an indoor unit including a load-side heat exchanger that causes heat exchange to be performed between air in an air-conditioned space and a heat medium subjected to heat exchange with the refrigerant; a flow rate detection unit that detects a flow rate of the heat medium; and an alarm unit provided in the indoor unit. The alarm unit includes a determination unit and an abnormality alarm unit. The determination unit determines whether an abnormality occurs in the indoor unit or not based on the flow rate detected by the flow rate detection unit. The abnormality alarm unit outputs an alarm when the determination unit determines that the abnormality occurs in the indoor unit.

First claim

The invention claimed is:

1. An air-conditioning apparatus comprising:
an outdoor unit including a compressor configured to compress and discharge refrigerant to a refrigerant circuit;
an indoor unit including a load-side heat exchanger configured to cause heat exchange to be performed between air in an air-conditioned space and a heat medium subjected to heat exchange with the refrigerant;
a flow rate detection unit configured to detect a flow rate of the heat medium; and
an alarm unit provided in the indoor unit, wherein
the alarm unit includes a processing circuit configured to
determine whether an abnormality occurs in the indoor unit or not based on the flow rate detected by the flow rate detection unit,
output an alarm when determining that the abnormality occurs in the indoor unit, and
output a serious alarm when a state of the abnormality is a high-urgency abnormal state in which an operation of the air-conditioning apparatus needs to be immediately stopped, and output a mild alarm when the state of the abnormality is a low-urgency abnormal state, the low-urgency abnormal state ending when maintenance on the air-conditioning apparatus is performed.

2. The air-conditioning apparatus of claim 1 , wherein
the processing circuit compares the flow rate with a first flow rate threshold and a second flow rate threshold that is less than the first flow rate threshold, and determines that the abnormality occurs, when the flow rate is less than the first flow rate threshold, and
the processing circuit outputs the mild alarm, when the flow rate is higher than or equal to the second flow rate threshold and is less than the first flow rate threshold, and outputs the serious alarm, when the flow rate is less than the second flow rate threshold.

3. The air-conditioning apparatus of claim 2 , further comprising
a flow control device configured to control the flow rate of the heat medium, wherein
the processing circuit calculates the first flow rate threshold and the second flow rate threshold based on a theoretical value of the flow rate that is determined depending on an opening degree of the flow control device.

4. The air-conditioning apparatus of claim 1 , further comprising:
an inlet temperature sensor configured to detect a temperature of the heat medium at a position close to an inlet of the load-side heat exchanger;
an outlet temperature sensor configured to detect the temperature of the heat medium at a position close to an outlet of the load-side heat exchanger;
a room temperature sensor configured to detect a temperature of the air-conditioned space; and
a suction temperature sensor configured to detect a suction temperature of air that is sucked into the indoor unit, wherein
the processing circuit
calculates a heat-medium heat exchange amount based on the flow rate and a temperature difference between a detected value obtained by the inlet temperature sensor and a detected value obtained by the outlet temperature sensor,
calculates an air heat exchange amount based on a detected value obtained by the room temperature sensor and a detected value obtained by the suction temperature sensor, and
calculates a heat-exchange amount difference that is a difference between the heat-medium heat exchange amount and the air heat exchange amount,

the processing circuit
compares the heat-exchange amount difference with a first heat exchange threshold and a second heat exchange threshold that is greater than the first heat exchange threshold, and
determines that the abnormality occurs, when the heat-exchange amount difference is greater than the first heat exchange threshold, and

the processing circuit outputs the mild alarm, when the heat-exchange amount difference is less than or equal to the second heat exchange threshold and is greater than the first heat exchange threshold, and the abnormality alarm unit outputs the serious alarm, when the heat-exchange amount difference is greater than the second heat exchange threshold.

5. The air-conditioning apparatus of claim 4 , wherein
the processing circuit calculates the first heat exchange threshold and the second heat exchange threshold based on aged deterioration of the load-side heat exchanger.

6. The air-conditioning apparatus of claim 1 , wherein
a heat-medium heat exchanger and a pump are provided in the outdoor unit, the heat-medium heat exchanger being connected to the load-side heat exchanger by a heat medium pipe, and configured to cause heat exchange to be performed between the heat medium and the refrigerant, the pump being configured to cause the heat medium to circulate through the heat medium pipe,
the processing circuit outputs the alarm to the outdoor unit, and
the outdoor unit reduces a rotation speed of the pump upon reception of the alarm from the processing circuit.

7. The air-conditioning apparatus of claim 1 , further comprising
a relay unit including a heat-medium heat exchanger and a pump, the heat-medium heat exchanger being connected to the load-side heat exchanger by a heat medium pipe, and configured to cause heat exchange to be performed between the heat medium and the refrigerant, the pump being configured to cause the heat medium to circulate through the heat medium pipe, wherein
the processing circuit outputs the alarm to the relay unit, and
the relay unit reduces a rotation speed of the pump upon reception of the alarm from the processing circuit.

8. The air-conditioning apparatus of claim 1 , comprising
a plurality of the indoor units, wherein
the processing circuit in each of the plurality of the indoor units determines whether the abnormality occurs in the indoor unit or not, and
the processing circuit in each of the plurality of the indoor units outputs the alarm when determining that the abnormality occurs in the indoor unit.

9. The air-conditioning apparatus of claim 8 , further comprising
a centralized controller connected to the alarm units of the plurality of the indoor units, wherein
the processing circuit in each of the plurality of the indoor units outputs the alarm to the centralized controller when determining that the abnormality occurs in the indoor unit.

10. The air-conditioning apparatus of claim 1 , further comprising
a communication unit provided in the indoor unit and configured to communicate with a remote control unit, wherein
the processing circuit outputs the alarm to the remote control unit via the communication unit.

11. The air-conditioning apparatus of claim 1 , wherein
the alarm unit includes a communication unit connected to a network, and
the processing circuit outputs the alarm to a mobile terminal connected to the network, via the communication unit.

Assignees

• Mitsubishi Electric Corp

Inventors

• Kadowaki Kimitaka

Classifications

• F24F11/36 Primary

  to leakage of heat-exchange fluid · CPC title

• F24F1/0007

  Indoor units, e.g. fan coil units (self-contained units F24F1/02) · CPC title

• F24F1/32

  for connecting the separate outdoor units to indoor units · CPC title

• F24F11/58

  using Internet communication · CPC title

• F24F11/85

  using variable-flow pumps · CPC title