Air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-12264838-B2
Application number	US-202018003536-A
Country	US
Kind code	B2
Filing date	Sep 7, 2020
Priority date	Sep 7, 2020
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

An air-conditioning apparatus includes an outdoor unit, multiple indoor units, and an intermediate unit. The indoor units each include a flow control device and an indoor controller. The intermediate unit includes an intermediate heat exchanger, a circulation device, and an intermediate controller. When at least one indoor unit starts operating, the intermediate controller determines whether a flow rate of a heat medium flowing into the intermediate heat exchanger is greater than or equal to a minimum flow rate. In response to determining that the flow rate is less than the minimum flow rate, the intermediate controller transmits an open instruction signal, representing an instruction to increase the opening degree of the flow control device, to the indoor controller of the indoor unit that is in a non-operation state. The indoor controller increases the opening degree of the flow control device in response to the received open instruction signal.

First claim

The invention claimed is:

1. An air-conditioning apparatus comprising:
a refrigerant circuit through which refrigerant circulates;
a heat medium circuit through which a heat medium circulates;
an outdoor unit located in the refrigerant circuit and configured to exchange heat between the refrigerant and outdoor air;
a plurality of indoor units located in the heat medium circuit and configured to exchange heat between the heat medium and indoor air to condition the indoor air; and
an intermediate unit located in the refrigerant circuit and the heat medium circuit and configured to exchange heat between the refrigerant and the heat medium and send the heat medium subjected to heat exchange with the refrigerant to the plurality of indoor units,
each of the plurality of indoor units including
a flow control device configured to regulate a flow rate of the heat medium leaving a corresponding one of the plurality of indoor units, and
an indoor controller configured to adjust an opening degree of the flow control device,

the intermediate unit including
an intermediate heat exchanger configured to exchange heat between the refrigerant and the heat medium,
a circulation device configured to circulate the heat medium between the intermediate heat exchanger and each of the plurality of indoor units, and
an intermediate controller configured to control the circulation device,

wherein the intermediate controller is configured to, when at least one indoor unit of the plurality of indoor units starts operating, determine whether a flow rate of the heat medium flowing into the intermediate heat exchanger from the plurality of indoor units is greater than or equal to a predetermined minimum flow rate, and in response to determining that the flow rate is less than the minimum flow rate, transmit an open instruction signal to the indoor controller of the indoor unit that is in a non-operation state of the plurality of indoor units, the open instruction signal representing an instruction to increase the opening degree of the flow control device, and
wherein the indoor controller is configured to, when receiving the open instruction signal, increase the opening degree of the flow control device in response to the open instruction signal.

2. The air-conditioning apparatus of claim 1 , wherein the intermediate controller is configured to, after transmitting the open instruction signal to the indoor controller of the indoor unit in the non-operation state, determine whether the flow rate is greater than or equal to the minimum flow rate, and in response to determining that the flow rate is less than the minimum flow rate, again transmit the open instruction signal to the indoor controller of the indoor unit in the non-operation state.

3. The air-conditioning apparatus of claim 1 ,
wherein the intermediate controller is configured to, in response to determining that the flow rate is less than the minimum flow rate when at least one indoor unit of the plurality of indoor units starts operating, transmit a first open instruction signal to the indoor controller of the indoor unit that is in the non-operation state and that includes the flow control device in a closed state, the first open instruction signal being one type of the open instruction signal and representing an instruction to cause the flow control device to enter an open state, and
wherein the indoor controller is configured to, when receiving the first open instruction signal, cause the flow control device to enter the open state in response to the first open instruction signal.

4. The air-conditioning apparatus of claim 3 , wherein the intermediate controller is configured to, in a case where the plurality of indoor units include two or more indoor units being in the non-operation state and including the flow control device in the closed state, transmit the first open instruction signal to the indoor controller of each of the two or more indoor units in the non-operation state, the first open instruction signal representing an instruction to adjust the opening degree of the flow control device to cause a ratio of capacities of the two or more indoor units in the non-operation state to be equal to a ratio of Cv values of the flow control devices of the two or more indoor units in the non-operation state.

5. The air-conditioning apparatus of claim 3 , wherein the intermediate controller is configured to, after transmitting the first open instruction signal to the indoor controller of the indoor unit in the non-operation state, determine whether the flow rate is greater than or equal to the minimum flow rate, and in response to determining that the flow rate is less than the minimum flow rate, transmit a second open instruction signal to the indoor controller of the indoor unit in the non-operation state, the second open instruction signal being an other type of the open instruction signal and representing an instruction to increase the opening degree of the flow control device by a predetermined opening degree.

6. The air-conditioning apparatus of claim 5 , wherein the intermediate controller is configured to, after transmitting the second open instruction signal to the indoor controller of the indoor unit in the non-operation state, determine whether the flow rate is greater than or equal to the minimum flow rate, and in response to determining that the flow rate is less than the minimum flow rate, again transmit the second open instruction signal to the indoor controller of the indoor unit in the non-operation state.

7. The air-conditioning apparatus of claim 1 , wherein the minimum flow rate is determined using a reduced temperature of the refrigerant upon activation of the outdoor unit and information on performance or specifications of the intermediate heat exchanger.

8. The air-conditioning apparatus claim 1 ,
wherein the outdoor unit starts operating in response to receiving an operation signal from the intermediate controller, the operation signal representing an instruction to operate, and
wherein the intermediate controller is configured to transmit no operation signal to the outdoor unit in response to determining that the flow rate is less than the minimum flow rate.

9. The air-conditioning apparatus of claim 8 ,
wherein the outdoor unit includes
a compressor configured to compress the refrigerant, and
an outdoor controller configured to communicate with the intermediate controller and cause the compressor to operate in response to the operation signal from the intermediate controller, and

wherein the intermediate controller is configured to transmit no operation signal to the outdoor controller in response to determining that the flow rate is less than the minimum flow rate.

10. The air-conditioning apparatus of claim 8 ,
wherein the intermediate controller is configured to
transmit the operation signal to the outdoor unit in response to determining that the flow rate is greater than or equal to the minimum flow rate, and
after a lapse of a predetermined refrigerant stabilization period, which is a time required for a temperature of the refrigerant to stabilize, from transmission of the operation signal, transmit a close instruction signal to the indoor controller of the indoor unit in the non-operation state, the close instruction signal representing an instruction to cause the flow control device to enter a closed state.

11. The air-conditioning apparatus of claim 9 ,
wherein the intermediate controller is configured to
transmit the operation signal to the outdoor controller in response to determining that the flow rate is greater than or equal to the minimum flow rate, and
after a lapse of a predetermined refrigerant

Assignees

• Mitsubishi Electric Corp

Inventors

• Furuya Koji
• Takenaka Naofumi
• Motomura Yuji
• Washiyama Hiroki

Classifications

• F24F1/0068

  characterised by the arrangement of refrigerant piping outside the heat exchanger within the unit casing · CPC title

• F25B2600/23

  Time delays · CPC title

• F25B2600/025

  by controlling speed · CPC title

• F25B2700/21163

  of the refrigerant at the outlet of the condenser · CPC title

• F25B2700/21162

  of the refrigerant at the inlet of the condenser · CPC title