US 9,851,132 B2 · Air conditioner

Abstract

This air conditioner performs a cooling operation and a heating operation in parallel with each other with an outdoor unit and indoor units connected together through two communication pipes. The air conditioner includes a switching mechanism changing the directions of refrigerants flowing through the communication pipes depending on whether a heating dominant operation is being performed in a first load region where a cooling load is relatively light or a second load region where the cooling load is heavier than in the first load region. In the second load region, the switching mechanism allows a low-pressure refrigerant to flow from the indoor units to the outdoor unit through the second communication pipe thicker than the first communication pipe to reduce a performance deterioration due to the pressure loss involved with the heating dominant operation.

Drawings

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Drawings

Claims20

Dependent claims

An air conditioner comprising:

a refrigerant circuit in which refrigerant flows through an outdoor unit, a gas-liquid separation unit, and a plurality of indoor units connected together through communication pipes and which is configured to be able to perform a refrigeration cycle in which cooling and heating operations are performed in parallel with each other, wherein
the communication pipes include a first communication pipe connecting the outdoor unit and the gas-liquid separation unit and a second communication pipe which has a larger inside diameter than the first communication pipe connecting the outdoor unit and the gas-liquid separation unit such that refrigerant flows from the outdoor from to the gas-liquid separation unit and from the gas-liquid separation unit to the outdoor unit,
the outdoor unit includes
a compressor that compresses the refrigerant,
an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air, and
a switching mechanism which changes the directions of the refrigerants flowing through the first and second communication pipes depending on whether a heating dominant operation to be conducted between a full-heating load operation and a balanced heating and cooling load operation is being performed in a first load region which ranges from a full-heating load to a partial-cooling load or a second load region which ranges from the partial-cooling load to balanced heating and cooling loads,
the switching mechanism includes
a switching valve that switches communication states of a discharge-side pipe of a compressor and a suction-side pipe of the compressor to allow one of the discharge-side pipe and the suction-side pipe to communicate with a gas-side end of the outdoor heat exchanger, and
a pipe switching section connected to the discharge-side pipe of the compressor, the first communication pipe, the second communication pipe, and a liquid-side end of the outdoor heat exchanger,
in the first load region, the switching mechanism allows a high-pressure refrigerant to flow from the outdoor unit to the indoor units through the second communication pipe, and allows a low-pressure refrigerant to flow from the indoor units to the outdoor unit through the first communication pipe, and
in the second load region, the switching mechanism allows the high-pressure refrigerant to flow from the outdoor unit to the indoor units through the first communication pipe, and allows the low-pressure refrigerant to flow from the indoor units to the outdoor unit through the second communication pipe.

8 more elements

A method for operating an air conditioner upgraded from an air conditioner, in which an outdoor unit and a plurality of indoor units are connected together through a first communication pipe and a second communication pipe, having a larger inside diameter than the first communication pipe, to allow a refrigerant circuit filled with a previous refrigerant to perform a cooling/heating switchable refrigeration cycle, into an air conditioner including a refrigerant circuit in which a new refrigerant, having a higher working pressure than the previous refrigerant, is used to perform a refrigeration cycle in which cooling and heating operations are performed in parallel with each other, wherein

at the time of upgrading the air conditioner, installed is a switching mechanism which changes the direction of a refrigerant flowing through the first and second communication pipes depending on whether a heating dominant operation conducted between a full-heating load operation and a balanced heating and cooling load operation is being performed in a first load region ranging from a full-heating load to a partial-cooling load or a second load region ranging from the partial-cooling load to balanced heating and cooling loads,
the air conditioner is operated such that the switching mechanism changes the directions of refrigerant flowing through the first and second communication pipes depending on whether the heating dominant operation to be conducted between the full-heating load operation and the balanced heating and cooling load operation is being performed in the first load region which ranges from the full-heating load to the partial-cooling load or the second load region which ranges from the partial-cooling load to balanced heating and cooling loads,
in the first load region, the switching mechanism allows a high-pressure refrigerant to flow from the outdoor unit to the indoor units through the second communication pipe, and allows a low-pressure refrigerant to flow from the indoor units to the outdoor unit through the first communication pipe, and
in the second load region, the switching mechanism allows a high-pressure refrigerant to flow from the outdoor unit to the indoor units through the first communication pipe, and allows a low-pressure refrigerant to flow from the indoor units to the outdoor unit through the second communication pipe.

1 more element

Dependencies are inferred from the claim text.

Description12,258 words

Summary3,824 words

#The present invention relates to an air conditioner including a plurality of indoor heat exchangers, and more particularly relates to an air conditioner configured to perform a cooling operation and a heating operation in parallel with each other.

#A so-called “cooling/heating free type air conditioner,” which is an indoor-multi-type air conditioner including a plurality of indoor units and which is configured to be able to perform a cooling operation and a heating operation in parallel with each other, has been known (see, e.g., Patent Document 1). The air conditioner of Patent Document 1 includes a cooling/heating switching unit between an outdoor unit having an outdoor heat exchanger and indoor units each having an indoor heat exchanger. The outdoor unit is connected with the cooling/heating switching unit through two communication pipes. The cooling/heating switching unit is also connected with each of the indoor units through two other communication pipes.

#In the air conditioner of Patent Document 1, the outdoor unit also includes a bridge circuit that defines the refrigerant flow directions to be constant in the communication pipes between the outdoor unit and the cooling/heating switching unit. On the other hand, changing the directions of the refrigerant flowing through the communication pipes between the cooling/heating switching unit and each indoor unit allows the indoor unit to selectively perform a cooling operation or a heating operation.

Brief description of the drawings11 figures

#FIG. 1 illustrates a refrigerant circuit of an air conditioner according to a first embodiment of the present invention.

#FIG. 2A is a graph showing four operation modes of the air conditioner by the ratio of a cooling load to a heating load. FIG. 2B is a table showing the flow directions of refrigerants on an operation mode basis.

#FIG. 3 illustrates a general configuration for an indoor-multi-type air conditioner in which multiple indoor units are connected in parallel with a single outdoor unit to make a switch from cooling to heating, and vice versa.

Detailed description8,153 words

#Embodiments of the present invention will now be described in detail below with reference to the drawings.

#First Embodiment of the Invention

#A first embodiment of the present invention will be described below.

Facts

Application

14/649,098Filed 29 Nov 2013

Priority

JP 2012-28828028 Dec 2012

Published

US 2015/0345842 A13 Dec 2015

Granted

26 Dec 2017

Term ends

13 Sep 2034

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 288 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification12 codes

F25B 41/20
Fluid-circulation arrangements: disposition of valves, e.g. of on-off valves or flow control valves
F24F 3/08
Characterised by the arrangements for the supply of heat-exchange fluid for the subsequent treatment of primary air in the room units: with…
F25B 13/00
Compression machines, plants or systems, with reversible cycle
F25B 2313/0231
Using multiple indoor units: with simultaneous cooling and heating

Timeline

28 Dec 2012Priority claimedJP 2012-288280
29 Nov 2013Application filedUS 14/649,098
3 Jun 2015Assigned to Daikin Industries, Ltd.assignment of assignor's interest
3 Dec 2015PublishedUS 2015/0345842 A1
26 Dec 2017GrantedUS 9,851,132 B2
12 Oct 2026TodayWithin its term
13 Sep 2034Term endsEstimated, includes 288 days of adjustment

Air conditioner

Life of this patent

Air conditioner

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims20

Description12,258 words

Drawings

Classification12 codes

Life of this patent

Description12,258 words