Air conditioning apparatus

Patent metadata

Field	Value
Publication number	US-9958170-B2
Application number	US-200913499878-A
Country	US
Kind code	B2
Filing date	Oct 22, 2009
Priority date	Oct 22, 2009
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

An air-conditioning apparatus includes indoor units including a plurality of use side heat exchangers that exchange heat between air and a heat medium, and a heat medium relay unit having a plurality of heat exchangers related to heat medium. A plurality of pumps deliver the heat medium involved in heating or cooling performed by the plurality of heat exchangers related to heat medium to each passage and circulate the heat medium. A plurality of heat medium flow switching devices perform switching so that the heat medium from a selected passage flows into and flows out of each use side heat exchanger. An expansion tank is connected to a passage alleviates a pressure change caused by a volumetric change of the heat medium, and a pressure equalizing pipe connects each inlet passage or each outlet passage of the heat medium sending devices.

First claim

The invention claimed is:

1. An air-conditioning apparatus, comprising:
indoor units including a plurality of use side heat exchangers that exchange heat between air with which heat is to be exchanged and a heat medium;
a heat medium relay unit including a plurality of heating/cooling units that heat or cool the heat medium, a plurality of heat medium pumps that deliver the heat medium involved in heating or cooling performed by the heating/cooling units to circulation passages corresponding to the heating/cooling units respectively and circulate the heat medium in each of the circulation passages, and a plurality of heat medium flow switching devices that each perform switching so that at least one heat medium in the plurality of passages corresponding to the heating/cooling units flow into and flow out of the corresponding use side heat exchanger;
a pressure absorber that connects to one of the passages, the pressure absorber alleviating a pressure change caused by a volumetric change of the heat medium; and
a pressure equalizer consisting of a pipe branched between an inlet passage of one pump corresponding to one circulation passage and an inlet passage of another pump corresponding to another circulation passage or branched between an outlet passage of the one pump corresponding to one circulation passage and an outlet passage of the another pump corresponding to the another circulation passage, the pressure equalizer pipe configured to eliminate a pressure difference caused by a temperature difference of the heat medium in the circulation passages, wherein the pressure equalizer pipe is sized so that a flow rate of the heat medium in the pressure equalizer pipe is less than or equal to ⅓ of the flow rate of the heat medium in the circulation passages.

2. The air-conditioning apparatus of claim 1 , the heating/cooling units being heat exchangers related to heat medium which exchange heat between a refrigerant and the heat medium, the air-conditioning apparatus further comprising an outdoor unit constituting a refrigerant circuit by connecting a compressor that pressurizes the refrigerant, a refrigerant flow switching device that switches a circulating channel of the refrigerant, a heat source side heat exchanger for the refrigerant to exchange heat, and an expansion device that adjusts pressure of the refrigerant with the heat exchangers related to heat medium thereto by piping.

3. The air-conditioning apparatus of claim 1 , further comprising a controller to control switching of the heat medium flow switching device corresponding to the use side heat exchanger in an indoor unit, operation of which has been suspended, so that each circulation passage corresponding to each of the heating/cooling units communicates with each other.

4. The air-conditioning apparatus of claim 3 , further comprising a plurality of flow rate control devices that each adjust a flow rate of the heat medium that is made to flow into and flow out of the corresponding use side heat exchanger, wherein
the controller controls the flow rate control device corresponding to the use side heat exchanger in the suspended indoor unit such that the heat medium does not flow into the indoor unit.

5. The air-conditioning apparatus of claim 1 , further comprising a controller to control switching of the heat medium flow switching device corresponding to the use side heat exchanger in an indoor unit, operation of which is temporarily suspended based on a target temperature of air with which heat is to be exchanged, so that each passage corresponding to each of the heating/cooling units communicates with each other when the controller determines that a suspended state has continued even after a predetermined time from the beginning of the suspension.

6. The air-conditioning apparatus of claim 1 , wherein the indoor units, the heat medium relay unit, and the outdoor unit are structured so as to be separately housed and placed at separate locations to each other.

7. The air-conditioning apparatus of claim 1 , wherein the pressure equalizer pipe is dimensioned so that a flow resistance of the heat medium in the pressure equalizer pipe is larger than a flow resistance in any set of two pipes that interconnect the heat medium relay unit and each of the indoor units.

8. The air-conditioning apparatus of claim 1 , further comprising a controller that enables
operation in a heating only operation mode, in which all of the plurality of heating/cooling units heat the heat medium and
operation in a cooling only operation mode, in which all of the plurality of heating/cooling units cool the heat medium,
the controller controlling, in the heating only operation mode and the cooling only operation mode, a heat medium flow switching device corresponding to an indoor unit in operation to switch such that the heat medium from all circulation passages flows into and flows out of the corresponding use side heat exchanger.

9. The air-conditioning apparatus of claim 2 , the heat exchangers related to heat medium comprising:
a heat exchanger related to heat medium for heating that heats the heat medium;

and a heat exchanger related to heat medium for cooling that cools the heat medium, wherein
the heat medium is made to circulate among the heat exchanger related to heat medium for heating and one or some of the plurality of use side heat exchangers, the heat medium is made to circulate among the heat exchanger related to heat medium for cooling and one or some of the remaining use side heat exchangers, and a cooling and heating mixed operation is performed in the plurality of the indoor units.

10. The air-conditioning apparatus of claim 1 wherein a circumference of the pressure equalizer pipe is smaller than a circumference of a pipe that interconnects the heat medium relay unit and each of the indoor units.

Assignees

• Yamashita Koji
• Morimoto Hiroyuki
• Motomura Yuji
• Mitsubishi Electric Corp

Inventors

• Yamashita Koji
• Morimoto Hiroyuki
• Motomura Yuji

Classifications

• F25B2313/02741

  using one four-way valve · CPC title

• F25B2600/0271

  the discharge pressure · CPC title

• F25B45/00

  Arrangements for charging or discharging refrigerant · CPC title

• F25B7/00

  Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit (F25B9/00 takes precedence) · CPC title

• F25B13/00

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