JP2529352B2 - Multi-room air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention has a refrigeration cycle control for simultaneously performing cooling operation and heating operation in each room in a multi-room air conditioner using air as a heat source. The present invention relates to a heat pump type air conditioner.

2. Description of the Related Art A conventional multi-room air conditioner having a plurality of indoor units includes a compressor 2, which is installed in an outdoor unit 1, as shown in FIG.
The four-way valve 3, the outdoor heat exchanger 4, the outdoor expansion valve 5, the indoor expansion valve 7 in the indoor unit 6 installed in parallel, and the indoor heat exchanger 8 are connected in parallel, A heat pump type refrigeration cycle is configured by sequentially connecting in a ring shape. Compressor 2
Has a variable capacity, and its capacity can be changed by changing the frequency of the supplied power. Further, the four-way valve 3 switches between cooling operation and heating operation, during the cooling operation, the refrigerant flows in the direction of the solid line arrow in the figure to form a cooling cycle, and during the heating operation, the refrigerant flows in the direction of the broken line in the figure. A heating cycle is formed. Also, the outdoor heat exchanger 4, and
An outdoor blower 9 and an indoor blower 10 are installed close to the indoor heat exchanger 8, respectively.

In such a multi-room air conditioner, a plurality of, for example, three indoor units 6a, 6b, 6c can be individually operated, and when only the indoor unit 6a is operated, another indoor unit 6b is operated. , 6c
Completely closes the indoor expansion valves 7b and 7c, and also stops the indoor blowers 10b and 10c. At this time, the compressor 2 can be operated with the capacity according to the number of operating indoor units by performing capacity control with an inverter or the like.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional example, the operation mode of the indoor unit 6 is set to the same mode for all three rooms, and for example, even in winter, two rooms perform heating operation,
One room had the drawback that it could not meet the needs for simultaneous heating and cooling operations, such as wanting to perform cooling operation.

Therefore, the present invention has two two-way valves and two expansion valves in each of the plurality of indoor units in the conventional refrigeration system, and a header is installed, and the two-way valve is provided between the outdoor expansion valve and the header. The purpose is to realize a simultaneous operation of heating and cooling by forming a bypass circuit via.

Means for Solving the Problems The technical means of the present invention for solving the above problems is an outdoor unit including a variable capacity compressor, a four-way valve, an outdoor heat exchanger, an outdoor blower, and an outdoor expansion valve, and an outdoor unit. A plurality of indoor units including an inner first two-way valve, an indoor heat exchanger, an indoor blower, an indoor second two-way valve, an indoor first expansion valve, and an indoor second expansion valve are connected in parallel. The outdoor unit and each indoor unit are connected by an indoor-side first two-way valve and an indoor-side second two-way valve, and the indoor-side first two-way valve and the room A circuit is formed that connects the interior heat exchanger and the interior second two-way valve and interior heat exchanger with the interior first expansion valve, the header, and the interior second expansion valve, and A bypass circuit is formed between the outdoor expansion valve and the header via a two-way valve.

Action The action of this technical means is as follows.

First, the capacities of the cooling and heating operations of each indoor unit are compared to determine the operation mode of the outdoor unit. That is,
When (total cooling capacity of indoor unit) ≥ (total heating capacity of indoor unit), the outdoor unit is in the cooling operation mode, and (total cooling capacity of indoor unit)
<(Total heating capacity of indoor unit) Set the outdoor unit to the heating operation mode. Then, the case of each operation mode of the outdoor unit will be described below.

<Outdoor unit: In cooling operation mode> Outdoor expansion valve: predetermined opening, indoor side first two-way valve of indoor unit in heating mode: open, indoor second second two-way valve: closed, indoor first Expansion valve: fully closed, indoor second expansion valve: fully open, indoor first two-way valve of indoor unit in cooling mode: closed, indoor second two-way valve: open, indoor first expansion valve: predetermined , Indoor second expansion valve:
Fully closed and two-way valve in bypass circuit: closed.
At this time, the high-temperature and high-pressure refrigerant sent from the outdoor heat exchanger passes through the indoor first second two-way valve of the indoor unit in the heating mode, flows into the indoor heat exchanger, and radiates heat indoors (heating operation). Then, after passing through the indoor second expansion valve and passing through the header, the refrigerant that has been decompressed by the indoor first expansion valve of the indoor unit in the cooling mode into the liquid or the two-phase state is indoors in the indoor heat exchanger. After the heat is absorbed from (cooling operation), it returns to the outdoor unit via the indoor second second two-way valve.

However, when the indoor unit is in all rooms: cooling mode, the two-way valve in the bypass circuit is opened, high-temperature high-pressure refrigerant is sent to the header, and the indoor first expansion valve of the indoor unit depressurizes the liquid or two-phase state. The absorbed refrigerant absorbs heat from the room in the indoor heat exchanger (cooling operation), and then returns to the outdoor unit via the indoor second two-way valve.

<Outdoor unit: In heating operation mode> Outdoor expansion valve: predetermined opening, indoor side first two-way valve of indoor unit in heating mode: closed, indoor second two-way valve: open, indoor first Expansion valve: predetermined, indoor second expansion valve: fully closed, indoor first two-way valve of indoor unit in cooling mode: open, indoor second two-way valve: closed, indoor first expansion valve: all Closed, indoor second expansion valve:
It is set to a predetermined value, and the two-way valve of the bypass circuit is closed.
At this time, the high-temperature high-pressure refrigerant sent from the outdoor heat exchanger passes through the indoor second second two-way valve of the indoor unit in the heating mode, flows into the indoor heat exchanger, and radiates heat indoors (heating operation). Then, after passing through the indoor-side first expansion valve, through the header, the refrigerant that has been decompressed by the indoor-side second expansion valve of the indoor unit in the cooling mode to become a liquid or a two-phase state is indoors in the indoor-side heat exchanger. After absorbing heat from the inside (cooling operation), it returns to the outdoor unit via the indoor-side first two-way valve.

As described above, headers are installed in a plurality of indoor units, and two two-way valves and two expansion valves are installed in each indoor unit, and
By controlling the two-way valve installed in the bypass circuit between the outdoor expansion valve and the header as described above, simultaneous heating and cooling operations can be realized.

Example Hereinafter, one example of the present invention will be described with reference to the accompanying drawings. The same components as those of the conventional example will be denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner according to an embodiment of the present invention. The heat pump type air conditioner of this embodiment includes an outdoor unit 1 including a variable capacity compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor blower 9, and an outdoor expansion valve 5, and an indoor first unit. Three indoor units 6 including two-way valve V1, indoor heat exchanger 8, indoor blower 10, indoor second two-way valve V2, indoor first expansion valve EV1, and indoor second expansion valve EV2 The outdoor unit 1 and each of the indoor units 6a, 6b, 6c are provided with an indoor-side first two-way valve V1a, V1b,
V1c is connected to the indoor second two-way valve V2a, V2b, V2c, and the indoor first two-way valve V1a to V1c and the indoor heat exchanger 8a to
8c, indoor second two-way valve V2a-V2c and indoor heat exchanger
Between 8a and 8c, indoor side first expansion valves EV1a to EV1c, header 20 common to each indoor unit, and indoor side second expansion valve EV2.
A circuit connecting a to EV2c is formed, and a bypass circuit is formed between the outdoor expansion valve 5 and the header 20 via the two-way valve BV.

 Next, the operation of the configuration of this embodiment will be described.

First, the operating modes of the outdoor unit are determined by comparing the capacities of the cooling and heating operations according to the operating modes set by the controllers of the indoor units. That is, if (total cooling capacity of indoor unit) ≥ (total heating capacity of indoor unit), the outdoor unit is in the cooling operation mode, and if (total cooling capacity of indoor unit) <(total heating capacity of indoor unit), outdoor unit Is set to the heating operation mode.
Then, depending on the operation mode of the outdoor unit, the outdoor expansion valve 5, the indoor first two-way valves V1a to V1c, the indoor second two-way valves V2a to V2c, the indoor first expansion valves EV1a to EV1c, and the indoor second second Expansion valves EV2a to EV2c,
Also, the following operation is performed by controlling the opening / closing or opening of the two-way valve BV.

<Outdoor Unit: Cooling Operation Mode> For example, the case of the indoor unit 6a: heating mode and the indoor units 6b, 6c: cooling mode will be described.

Outdoor expansion valve 5: predetermined opening, indoor first two-way valve V1a of indoor unit 6a in heating mode: open, indoor second two-way valve V2a: closed, indoor first expansion valve EV1a: fully closed , Indoor side second expansion valve EV2a: indoor side first two-way valve V1 of the indoor units 6b, 6c in the cooling mode when fully opened
b, V1c: closed, indoor second two-way valve V2b, V2c: open, indoor first expansion valve EV1b, EV1c: predetermined, indoor second expansion valve EV2b, EV2c: fully closed, and further bypass circuit Two-way valve BV: Closed. At this time, the high-temperature and high-pressure refrigerant sent from the outdoor heat exchanger 4 passes through the indoor-side first two-way valve V1a of the indoor unit 6a in the heating mode,
It flows into the indoor heat exchanger 8 and radiates heat to the room (heating operation). After that, it passes through the indoor second expansion valve V2a and passes through the header 2
Through 0, the refrigerant that has been decompressed by the indoor-side first expansion valves V1b, V1c of the indoor units 6b, 6c in the cooling mode to become a liquid or a two-phase state absorbs heat from the room by the indoor heat exchangers 8b, 8c. After cooling (cooling operation), the outdoor unit 1 is operated via the indoor second two-way valves V2b, V2c.
Return to the four-way valve 3 inside.

However, when the indoor units 6a to 6c are all in the room: cooling mode, the two-way valve BV of the bypass circuit is opened, the high-temperature high-pressure refrigerant is sent to the header 20, and the indoor-side first expansion valve V1a of the indoor units 6a to 6c. ~ V
The refrigerant that was decompressed in 1c and became a liquid or a two-phase state absorbed heat from the room inside the indoor heat exchangers 8a to 8c (cooling operation).
Then, it returns to the four-way valve 3 in the outdoor unit 1 via the indoor second two-way valves V2a to V2c.

<Outdoor unit: heating operation mode> For example, the case of the indoor unit 6a: cooling mode and the indoor units 6b, 6c: heating mode will be described.

Outdoor expansion valve 5: indoor unit 6b, 6 in a predetermined opening and heating mode
c indoor side two-way valve V1b, V1c: closed, indoor side two-way valve V2
b, V2c: open, indoor first expansion valve EV1b, EV1c: predetermined, indoor second expansion valve EV2b, EV2c: fully closed, indoor first first two-way valve V1a of indoor unit 6a in cooling mode: open, The indoor second two-way valve V2a: closed, the indoor first expansion valve EV1a: fully closed, the indoor second expansion valve EV2a: predetermined, and further, the bypass circuit two-way valve BV: closed. At this time, the high-temperature and high-pressure refrigerant sent from the outdoor heat exchanger 4 passes through the indoor second second two-way valves V2b, V2c of the indoor units 6b, 6c in the heating mode and flows into the indoor heat exchangers 8b, 8c. , Dissipate heat indoors (heating operation). Then, after passing through the indoor-side first expansion valves V1b and V1c and passing through the header 20, the refrigerant that has been decompressed by the indoor-side second expansion valve EV2a of the indoor unit 6a in the cooling mode to become the liquid or the two-phase refrigerant is stored in the room. After absorbing heat from the inside of the room by the inner heat exchanger 8a (cooling operation), it returns to the outdoor expansion valve 5 in the outdoor unit 1 via the indoor first two-way valve V1a.

As described above, headers are installed in a plurality of indoor units, and two two-way valves and two expansion valves are installed in each indoor unit, and
By controlling the two-way valve installed in the bypass circuit between the outdoor expansion valve and the header as described above, simultaneous heating and cooling operations can be realized.

Incidentally, in the above embodiment, the header 20 is each indoor unit 6a, 6b, 6c
However, the same effect can be obtained by installing a dedicated header in each indoor unit 6a, 6b, 6c and connecting the headers with pipes having different diameters.

As described above, headers are installed in a plurality of indoor units, and two two-way valves and two expansion valves are installed in each indoor unit, and
By controlling the two-way valve installed in the bypass circuit between the outdoor expansion valve and the header as described above, simultaneous heating and cooling operations can be realized.

EFFECTS OF THE INVENTION As described above, according to the present invention, the outdoor unit including the variable capacity compressor, the four-way valve, the outdoor heat exchanger, the outdoor blower, and the outdoor expansion valve, the indoor first two-way valve, and the indoor side. A refrigeration cycle in which a plurality of indoor units including a heat exchanger, an indoor blower, an indoor second two-way valve, an indoor first expansion valve, and an indoor second expansion valve are connected in parallel to form a main circuit. The outdoor unit and each indoor unit are connected by an indoor-side first two-way valve and an indoor-side second two-way valve, and between the indoor-side first two-way valve and the indoor-side heat exchanger and the room. A circuit connecting the inner second two-way valve and the indoor heat exchanger with the indoor first expansion valve, a header common to each indoor unit, and the indoor second expansion valve is formed, and By forming a bypass circuit via a two-way valve between the outdoor expansion valve and the header, each room in the multi-room air conditioner It is possible to realize simultaneous cooling and heating operations.

[Brief description of drawings]

FIG. 1 is a refrigeration system diagram of a heat pump type air conditioner according to an embodiment of the present invention, and FIG. 2 is a refrigeration system diagram of a heat pump type air conditioner showing a conventional example. 1 ... Outdoor unit, 2 ... Variable capacity compressor, 3 ... Four-way valve,
4 ... Outdoor heat exchanger, 5 ... Outdoor expansion valve, 6a-6c ...
… Indoor unit, 8a to 8c …… Indoor heat exchanger, 9 …… Outdoor blower, 10a to 10c …… Indoor blower, V1a to V1c …… Indoor 1st two-way valve, V2a to V2c …… Room Inner second two-way valve, EV1a-EV
1c: 1st indoor expansion valve, EV2a to EV2c: 2nd indoor expansion valve, 20: header, BV: 2-way valve.

Claims (1)

(57) [Claims] 1. An outdoor unit comprising a variable capacity compressor, a four-way valve, an outdoor heat exchanger, an outdoor blower, and an outdoor expansion valve,
Multiple indoor units consisting of indoor first two-way valve, indoor heat exchanger, indoor blower, indoor second two-way valve, indoor first expansion valve, and indoor second expansion valve are connected in parallel. The outdoor unit and each indoor unit are connected by the indoor first two-way valve and the indoor second two-way valve, and the indoor first first two-way valve is provided. And a room-side heat exchanger, and a room-side second two-way valve and a room-side heat exchanger are connected by a room-side first expansion valve, a header, and a room-side second expansion valve. A multi-chamber air conditioner characterized in that a bypass circuit having a two-way valve is formed between the outdoor expansion valve and the header.