JPH0350467A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent any chattering of a changeover valve by providing on a high pressure gas branch tube a check valve for preventing a refrigerant from flowing from a room heat exchanger to a high pressure gas tube, and connecting each room heat exchanger with a fluid tube via a refrigerant pressure reducer. CONSTITUTION:A title air conditioner comprises a high pressure gas tube 11 in which a unit to unit piping 10 for connecting an outdoor unit 1 and room units (5a)(5b)(5c) is connected in branching with a refrigerant discharge tube 7, a low pressure gas tube 12 connected in branching with a refrigerant suction tube 8, and a fluid tube 13 connected to the other end of an outdoor heat exchanger (3). On branched high pressure gas branch tubes (11a)(11b)(11c), there are provided check valves (16a)(16b)(16c) for preventing a refrigerant from flowing from room heat exchangers (6a)(6b)(6c) to the high pressure gas tube 11. Such provision of the check valve (16b) eliminated application of differential pressure oppositely to the changeover valve (14b), and hence any chattering any genertion of abnormal sound are prevented.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is composed of an outdoor unit and a plurality of indoor units, and is capable of cooling or heating all of the plurality of rooms at the same time, and cooling any room at the same time. This article relates to a multi-room heather air conditioner that heats other rooms. (Example) Conventional technology A multi-room air conditioner that can simultaneously cool or heat all of multiple rooms and simultaneously cool one room and heat the other rooms is disclosed in Japanese Patent Publication No. 52-24710. 52-2
This is disclosed in Publication No. 4711 and Japanese Utility Model Publication No. 54-3020.

(c) Problems to be solved by the invention
The device presented in Publication No. 24711 requires as many four-way switching valves and outdoor heat exchangers as there are indoor units, which complicates the piping circuit configuration, increases manufacturing costs, and requires two units for each indoor unit. Since the inter-unit piping must be drawn out from the outdoor unit, the number of inter-unit piping increases, making piping work cumbersome. Moreover, during air-conditioning operation that cools one room and heats another room at the same time, the outdoor heat exchanger that corresponds to each indoor unit acts as a condenser and an evaporator, respectively, and discards heat outdoors, making it difficult to recover heat. there were.

Furthermore, in the device disclosed in the above-mentioned Japanese Utility Model Publication No. 54-3020, during air-conditioning operation that simultaneously cools one room in a plurality of rooms and heats others, the combination of rooms that can be cooled and rooms that can be heated is However, the heating and cooling operation cannot be freely selected and performed in each room, and has the drawback of being inconvenient to use.

The present invention solves the above-mentioned problems and provides a getter chamber type air conditioner that prevents chattering of the switching valve.

(2) Means for Solving the Problems The present invention connects one end of an outdoor heat exchanger to a refrigerant discharge pipe and a refrigerant suction pipe of a compressor via a switching valve, while connecting an outdoor unit and a plurality of indoor units. The inter-unit piping is connected to the low-pressure gas pipe that is branch-connected to the refrigerant suction pipe of the compressor, the high-pressure gas pipe that is branch-connected to the refrigerant discharge pipe of the compressor, and the other end of the outdoor heat exchanger. It consists of a liquid pipe and
When one end of the indoor heat exchanger of each indoor unit is branch-connected to a high-pressure gas pipe and a low-pressure gas pipe via a switching valve, refrigerant flows from the indoor heat exchanger to the high-pressure gas pipe through this branched high-pressure gas branch pipe. A check valve is provided to prevent the liquid from flowing, and the other end of each indoor heat exchanger is connected to the liquid pipe via a refrigerant pressure reducer.

(*〉Operation When cooling all rooms at the same time, by setting the switching valve of the outdoor heat exchanger and the switching valve of each indoor heat exchanger to the cooling state, the refrigerant discharged from the compressor can be After flowing into the outdoor heat exchanger where it is condensed and liquefied, it is distributed to the refrigerant pressure reducer of each indoor unit via liquid pipes, and then evaporated and vaporized in each indoor heat exchanger, and then transferred to the low-pressure gas pipe and the refrigerant. The air is sucked into the compressor through the suction pipe.In this way, the entire room is cooled by each indoor heat exchanger that acts as an evaporator.

In addition, when heating all rooms at the same time, by setting the switching valve of the outdoor heat exchanger and the seppuku valve of each indoor heat exchanger to the heating state, the refrigerant discharged from the compressor is transferred to the discharge pipe and the high-pressure gas. The gas is distributed to each indoor heat exchanger through a pipe and a high-pressure gas branch pipe, where it is condensed and liquefied, and then passed through each refrigerant pressure reducer and combined in a liquid pipe, after which it is evaporated and vaporized in an outdoor heat exchanger. After that, the refrigerant is sucked into the compressor through the refrigerant suction pipe. In this way, all rooms are heated by each indoor heat exchanger acting as a condenser.

Also, if you want to simultaneously cool two rooms and heat one room, set the switching valve of the outdoor heat exchanger to the heating state and set the switching valve of the indoor heat exchanger of the indoor unit to be cooled to the cooling state. When the switching valve of the indoor heat exchanger of the indoor unit to be heated is set to the heating state, part of the refrigerant discharged from the compressor flows to the outdoor heat exchanger, and the remaining refrigerant flows between the high-pressure gas pipe and the high-pressure gas pipe. It flows through the branch pipe to the indoor heat exchanger of the heating indoor unit, and is condensed and liquefied in the indoor heat exchanger and outdoor heat exchanger. The refrigerant condensed and liquefied in these heat exchangers is distributed to the refrigerant pressure reducers of each indoor unit via liquid pipes, and then evaporated in each indoor heat exchanger.
Thereafter, the refrigerant is sucked into the compressor through a low-pressure gas pipe and a refrigerant suction pipe. In this way, one room is heated by the indoor heat exchanger that acts as a condenser, and two rooms are cooled by the other indoor heat exchanger that acts as an evaporator. In such operation, when switching from all-room heating operation to two-room cooling/single-room heating operation, part of the refrigerant discharged from the compressor begins to flow into the outdoor heat exchanger, causing a temporary drop in refrigerant pressure in the refrigerant discharge pipe. When the refrigerant pressure becomes lower than the refrigerant pressure of the indoor heat exchanger that continues heating operation, differential pressure will be applied in the opposite direction to the one-way switching valve connected to this indoor heat exchanger, but the check valve Because of this, there is no differential pressure applied, and this switching valve does not cause ticketing or abnormal noise. (f) Example To explain the example of the present invention based on the drawings, (1) is a compressor (2), an outdoor heat exchanger (3), and a gas-liquid separator (4).
(5a) (5b) (5c)
is an indoor unit that has indoor heat exchangers (6a), (6b), and (6c), and one end of the outdoor heat exchanger (3) is connected to the compressor (2).
A switching valve (9) is installed between the refrigerant discharge pipe (7) and the refrigerant suction pipe (8).
a) Connect the inter-unit piping (10) that connects the outdoor unit (1) and the indoor units (5a) (5b) (5c) via the refrigerant discharge pipe (7) to the refrigerant discharge pipe (7).
A high pressure gas pipe (11) branch-connected to the refrigerant suction pipe (
8> and a liquid pipe (13) connected to the other end of the outdoor heat exchanger (3). ) (6c) are connected to the high pressure gas pipe (l1) and the low pressure gas pipe (12) with switching valves (14a) (15a), (14b)<15b), respectively.
, (14c) and (15c), and these branched high pressure gas branch pipes (lla) (llb) (
check valves (16a) (16b) (16c) that prevent the refrigerant from flowing from the indoor heat exchangers (6a) (6b) (6c) to the high pressure gas pipe (11) are installed in the liC), and each indoor heat exchanger Connect the other ends of the containers (6a) (6b) (6c) to the liquid pipe (13) and refrigerant pressure reducers (17a) (17b) (such as electric expansion valves).
17c). Next, the driving operation will be explained. When cooling all rooms at the same time, open one switching valve (9a) of the outdoor heat exchanger (3) and close the other switching valve (9b), and close the indoor heat exchanger (3).
6a) (6b) (6c) One switching valve (14a) (
14b) (14c) and close the other switching valve <L
By opening 5a)<15b)<150), the refrigerant discharged from the compressor (2) is transferred to the discharge pipe (7>, the switching valve
9a), the outdoor heat exchanger (3>), where it is condensed and liquefied, and then passed through the liquid pipe (13>) to each indoor unit (5a).
(5b) (5c) Refrigerant pressure reducer <17a) (17b) (
17c), where it is depressurized.

After that, after being evaporated in each indoor heat exchanger (<6g) (6b) (6c), the switching valves (15a) (15b) (1
5c), the low-pressure gas pipe (12), the suction pipe (8), and the gas-liquid separator (4) and are sucked into the compressor m(2).In this way, each indoor heat exchanger (2) acts as an evaporator. 6g) (
6b) (6c) cools all rooms at the same time. Conversely, if you want to heat all rooms at the same time, use an outdoor heat exchanger (3)
Close one switching valve (9a) and close the other switching valve (9a).
9b), and indoor heat exchanger (6a) (6b)(
6C) One switching valve <14a) (14b) (14c)
Open the other switching valve (15a) (15b) (1
By closing 5c), the refrigerant discharged from the compressor (2> passes through the discharge pipe (7), high pressure gas pipe (11), high pressure gas branch pipes (lla), (llb) (11C) in sequence, and passes through the check valve. (16a) (16b) (16c), switching valve (14g
) (14b) (14c), indoor heat exchanger (6a) (6b
) and (6c), where they are respectively condensed and liquefied.
Each refrigerant pressure reduction'M (17a>( 17b)( 17c)
The pressure is reduced and the liquid is combined in the pipe (13), then evaporated in the outdoor heat exchanger (3), and then connected to the switching valve (9b), the suction pipe (8), and the gas-liquid separator (4). The air is then sucked into the compressor (2>). In this way, all the rooms are heated at the same time by the indoor heat exchangers (6a) (6b) (6c) which act as condensers.

In addition, when simultaneously cooling two rooms and heating one room at the same time, open one switching valve (9a) of the outdoor heat exchanger 3) and close the other switching valve (9b). One switching valve (14a) of the indoor unit (5a) (5c)
) (14c) and close the other switching valve (15a).
Indoor unit (5b) that opens and heats (15c)
One switching valve (14b) is opened, and the other switching valve (14b) is opened.
15b), a part of the refrigerant discharged from the compressor (2) sequentially passes through the discharge pipe (7> and the switching valve (9a)) and flows into the outdoor heat exchanger (3), and the remaining refrigerant is converted into high-pressure gas. Check valve (16b) of pipe (11) and high pressure gas branch pipe (llb)
) of the indoor unit (5b) that conducts -cBEJ through -cBEJ (
14b), flows to the indoor heat exchanger (6b>), and is condensed and liquefied in this indoor heat exchanger (6b) and the outdoor heat exchanger (3). ) The refrigerant is condensed and liquefied in the indoor unit (5 g
After being depressurized by the refrigerant pressure reducers (17a) (17c) of > (5c), the refrigerant is evaporated by the respective indoor heat exchangers (6a) (6c), and then each switching valve (15a) <15c) The gas is combined in the low-pressure gas pipe (12) through the suction pipe (8) and the gas-liquid separator (4), and is sucked into the compressor (2).In this way, the indoor heat exchanger acts as a condenser. (6b) heats one room, and the other indoor heat exchangers (6a) (6c), which act as evaporators, cool two rooms.In this way, each indoor unit (5a) (5b) (5c)
are the respective switching valves (14a) (15a). (14b)
By opening and closing (15b), (14c) and (15c), it is possible to perform heating and cooling operations as desired. In this operation, when switching from all-room heating operation to two-room cooling operation and one-room heating operation, a part of the refrigerant discharged from the compressor (2) begins to flow into the outdoor heat exchanger <3>, and the refrigerant discharge pipe (7>
The refrigerant pressure of the indoor heat exchanger (5b) decreases temporarily and becomes lower than the refrigerant pressure of the indoor heat exchanger (5b) that continues heating operation (i.e.,
In the refrigerant pressure PA at the location (A) of the refrigerant discharge pipe (7>), the refrigerant pressure P at the location (B) of the high-pressure gas branch pipe (llb), and the refrigerant pressure Pc at the location (C), P A < P m
< P c), and a one-way switching valve (14b) that is completely closed in the direction of the arrow shown in the figure, but opens in the opposite direction due to the differential pressure of the refrigerant, is subjected to differential pressure in the opposite direction. If this switching valve (14b) is energized in this state, there is a risk that this switching valve (14b) will cause chittering and abnormal noise, but since a check valve (16b) is provided. No differential pressure is applied to the switching valve (14b) in the opposite direction, and the above-mentioned chattering and abnormal noises do not occur.

In addition, when the compressor <<2>> stops during all-room heating operation or simultaneous cooling/heating operation, the liquid refrigerant condensed in the indoor heat exchanger (6b) of the indoor unit <5b> that was in heating operation leaks from the switching valve (14b) and reaches the check valve (16b), but since the liquid refrigerant is blocked by the check valve (16b), the liquid refrigerant does not return to the high-pressure gas pipe (11). .

In addition, in the above embodiment, the switching valves (9a) (9b), (
14a) (15a) , (14a) (15b) ,
Two-way valves were used for (14c) and (15c), but instead, switching valves (9a) and (10a) were used as three-way valves, and switching valves (14a and 15a) were used as three-way valves, for a total of four. A three-way valve may also be used. (G) Effects of the invention In the present invention, the inter-unit piping that connects the outdoor unit and multiple indoor units is composed of three refrigerant pipes: a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe. With a simple circuit configuration using an outdoor heat exchanger, you can freely select and perform simultaneous cooling and heating operations on any indoor unit, as well as simultaneous cooling and heating operations for multiple indoor units. In addition, during simultaneous heating and cooling operation, the indoor heat exchanger that functions as a condenser and the indoor heat exchanger that functions as an evaporator are connected in series, so that efficient operation can be performed by heat recovery.

Moreover, a check valve is installed in the high-pressure gas branch pipe that branches from the high-pressure gas pipe to prevent refrigerant from flowing from the indoor heat exchanger to the high-pressure gas pipe, so when the indoor unit switches from cooling operation to heating operation. , it is possible to prevent the switching valve of this indoor unit from chattering or generating abnormal noise, and it is also possible to prevent the liquid refrigerant in the indoor heat exchanger from returning to the high-pressure gas pipe when the heating operation is stopped. ．．

[Brief explanation of drawings]

The drawing is a refrigerant circuit diagram of an air conditioner showing an embodiment of the present invention.

Claims (1)

[Claims] (1) In an air conditioner in which an outdoor unit having a compressor and an outdoor heat exchanger and multiple indoor units having indoor heat exchangers are connected by inter-unit piping, one end of the outdoor heat exchanger is connected to the compressor. a low-pressure gas pipe branch-connected to the refrigerant discharge pipe and the refrigerant suction pipe via a switching valve, and a low-pressure gas pipe branch-connected to the suction pipe with the inter-unit piping; and a high-pressure gas pipe branch-connected to the discharge pipe; It consists of a liquid pipe connected to the other end of the outdoor heat exchanger, and one end of each indoor heat exchanger is branch-connected to the high-pressure gas pipe and the low-pressure gas pipe via a switching valve, and the branched high-pressure A check valve is installed in the gas branch pipe to prevent refrigerant from flowing from the indoor heat exchanger to the high-pressure gas pipe.
An air conditioner characterized in that the other end of each indoor heat exchanger is connected to the liquid pipe via a refrigerant pressure reducer.