JPH0355474A - Air conditioning apparatus - Google Patents

Abstract

PURPOSE:To freely select air conditioning operation in each room by connecting one end of each indoor heat exchanger to a high pressure gas pipe and a low pressure gas pipe via a changeover valve, connecting the other end to a fluid pipe via a refrigerant pressure reducer, and further providing a refrigerant flow rate control on at least one among fluid branch pipes. CONSTITUTION:In the case where all rooms are simultaneously cooled, for example, once changeover valves (9a), (9b), (9c) of outdoor heat exchangers (3a), (3b), (3c) are opened, the other changeover valves (10a), (10b), (10c) are closed, and one changeover valves (15a), (15b), (15c) of indoor heat exchangers (16a), (16b), (16c) are opened. Hereby, the refrigerant discharged from a compressor (2) flows through the changeover valves (9a), (9b), (9c), and the outdoor heat exchanges (3a), (3b), (3c) parallely, where it is condensed and liqufied and thereafter it is distributed to refrigerant pressure reduces (17a), (17b), (17c) of each indoor unit (5a), (5b), (5c) after passing through the refrigerant flow rate control valves (18a), (18b), (18c) fully opened, and a fluid pipe (14), and reduced in pressure. Further, after the refrigerant is evaporated through each indoor heat exchangers (17a), (17b), (17c), sucked into the compressor 2. Thus, all rooms are simultaneously cooled by each indoor heat exchangers cooled by each indoor heat exchangers (6a), (6b), (6c) acting as an evaporator.

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 simultaneously cooling or heating all of a plurality of rooms, and cooling a certain room at the same time. The present invention relates to a multi-room air conditioning system that heats other rooms.

(Example) Conventional technology A multi-room air conditioning system 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. -24
This is disclosed in Japanese Patent Publication No. 711, Japanese Patent Publication No. 52-27459, and Publication Utility Model Publication No. 3020-1983.

(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, resulting in troublesome piping work. Moreover, during air-conditioning operation that simultaneously cools one room and heats another room, the outdoor heat exchanger that corresponds to each indoor unit acts as a condenser and an evaporator, respectively, and discards heat outdoors.
The problem was that heat could not be recovered.

In addition, the above-mentioned Japanese Patent Publication No. 52-27459 and Utility Model Publication No. 5
In the device presented in Publication No. 4-3020, 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 determined, and the air-conditioning operation can be performed in each room. It has the disadvantage that it cannot be freely selected and is not easy to use.

It is an object of the present invention to solve the above-mentioned problems and to provide a multi-room air conditioning system that can provide heating and cooling capacity commensurate with the heating and cooling load during simultaneous heating and cooling operations. (2) Means for Solving the Problems The present invention connects one end of each of a plurality of outdoor heat exchangers to a refrigerant discharge pipe and a refrigerant suction pipe of a compressor via a switching valve, while connecting the outdoor unit A unit 1 inter-unit piping provided between the plurality of indoor units, a high-pressure gas pipe branch-connected to the discharge pipe, a low-pressure gas pipe branch-connected to the suction pipe, and a plurality of outdoor heat exchangers. The other end of each indoor heat exchanger is connected to the high pressure gas pipe and the low pressure gas pipe via a switching valve, and one end of each indoor heat exchanger is connected to the high pressure gas pipe and the low pressure gas pipe via a switching valve. The other end of the heat exchanger is connected to the liquid pipe through a refrigerant pressure reducer, and at least one of the liquid branch pipes is provided with a refrigerant flow rate control valve. In the case of cooling 1, by setting the switching valve of each outdoor heat exchanger and the switching valve of each indoor heat exchanger to the cooling state, the refrigerant discharged from the compressor is transferred from the discharge pipe to each outdoor heat exchanger. After flowing and condensing and liquefied here, it is distributed to the refrigerant pressure reducer of each indoor unit via the refrigerant flow control valve and liquid pipe, and then evaporated in each indoor heat exchanger, and then transferred to the low-pressure gas pipe and the refrigerant suction. In this way, all the rooms are cooled by each indoor heat exchanger that acts as an evaporator.In addition, when heating all rooms at the same time, each outdoor heat exchanger By setting the switching valve of 1 and the switching valve of each indoor heat exchanger to the heating state, the refrigerant discharged from the compressor is distributed to each indoor heat exchanger through the discharge pipe and the high-pressure gas pipe in sequence. After each refrigerant is condensed and liquefied, it passes through each refrigerant pressure reducer and is combined in a liquid pipe.Then, it passes through a refrigerant flow control valve, is evaporated in each outdoor heat exchanger, and is then sucked into a compressor through a refrigerant suction pipe. .

In this way, all rooms are heated by each indoor heat exchanger acting as a condenser.

In addition, when simultaneously cooling two rooms and heating one room, for example, set the switching valve of one outdoor heat exchanger to the cooling state, close the switching valve of the other outdoor heat exchanger, and cool the room. When the switching valve of the indoor heat exchanger of the indoor unit is set to the cooling state and the switching valve of the indoor heat exchanger of the indoor unit that is heating is set to the heating state, a portion of the refrigerant discharged from the compressor is transferred to one of the outdoor units. The refrigerant flows only to the heat exchanger, and the remaining refrigerant flows through the high-pressure gas pipe to the indoor heat exchanger of the heating indoor unit, where it is condensed and liquefied in the indoor heat exchanger and the 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, then evaporated in each indoor heat exchanger, and then transferred to the low pressure gas pipe and refrigerant suction pipe. and is then sucked into the compressor.

In this way, one room is heated by the indoor heat exchanger acting as a condenser, and two rooms are cooled by the other indoor heat exchanger acting as an evaporator.

Also, when simultaneously cooling one room and heating two rooms, the switching valve of one outdoor heat exchanger is set to the heating state, the switching valve of the other outdoor heat exchanger is closed, and the air is cooled. When the switching valve of the indoor heat exchanger of the indoor unit is set to the cooling state and the switching valve of the indoor heat exchanger of the indoor unit that is heating is set to the heating state, the refrigerant discharged from the compressor passes through the high-pressure gas pipe and heats the room. It flows to each indoor heat exchanger of each indoor unit, and is condensed and liquefied in these indoor heat exchangers. The refrigerant condensed and liquefied in these heat exchangers is depressurized in each refrigerant pressure reducer, and then passed through liquid pipes to the indoor heat exchanger of the indoor unit that cools the room, and the remaining liquid refrigerant is evaporated in the outdoor heat exchanger. It is vaporized and then passed through a low-pressure gas pipe and a refrigerant suction pipe in sequence before being sucked into the compressor. In this way, two rooms are heated by the indoor heat exchanger acting as a condenser, and one room is cooled by the other indoor heat exchanger acting as an evaporator.

During such simultaneous cooling and heating operation, the switching valves of the plurality of outdoor heat exchangers are opened and closed according to the temperatures of the indoor heat exchangers of the indoor unit in the cooling operation and the indoor unit in the heating operation. If this capacity control alone is insufficient, the outdoor heat exchanger is finely adjusted to an appropriate heat exchange capacity commensurate with the indoor heating and cooling load by reducing the opening degree of the refrigerant flow control valve.

(f) Example An example of the present invention will be explained based on the drawings. The outdoor units (5a), (5b), and (5c) having gas-liquid separators (4) have the same heat exchange capacity or different indoor heat exchangers (6a) and (6).
b) In an indoor unit with (6c), an outdoor heat exchanger (
3a) Connect one end of each of (3b) and (3c) to a compressor (2)
The outdoor switching valves (9a) (10a), (9b) (10b),
(9c) (10c) while connecting the outdoor unit (1> and indoor unit (5a) (5b) (5c)
The inter-unit piping (11) that connects the refrigerant discharge pipe (7
A high-pressure gas pipe (12) branch-connected to the refrigerant suction pipe <8>, a low-pressure gas pipe (13) branch-connected to the refrigerant suction pipe <8>, and the other end of the outdoor heat exchanger (3a) (3b) (3c) Liquid branch pipe (
Each indoor heat exchanger (6a) (6
b) Connect (6c) to the high pressure gas pipe (12> and low pressure gas pipe (13)
〉 are indoor switching valves (15a) (16a), respectively.
(15b), (16b), (15c), and (16c), and connects to the liquid pipe (14) via refrigerant pressure reducers (17a), (17b), and (17c) such as electric expansion valves. Take it. (18a) (18b) (18c) are liquid branch pipes (14a)
(14b) (14c) are electrically operated refrigerant flow control valves, and (19) is a plurality of outdoor heat exchangers (3a) (3b) (3C) installed in the same air path for heat exchange with outside air. (20a) (20b) (20
c) is an indoor blower.

(21) is a controller, and indoor heat exchanger (6a) (6b)
(6c) temperature sensor (22a) (22b) (22c)
), and depending on this detected temperature, the outdoor switching valve (
9a) (10a) . (9b) (10b) , (9
c) Open and close (10c) to connect outdoor heat exchanger (3a) (3
b) Controls the capacity of (3c) and also controls the outdoor blower (19).
), and if this is still not possible, the opening degrees of the refrigerant flow control valves (18a), (18b), and (18c) are reduced. Next, the driving operation will be explained. When cooling all rooms at the same time, open one outdoor switching valve (9a), (9b), and (9c) of each of the outdoor heat exchangers (3a, 3b, and 3c), and open the other outdoor switching valve ( 10a) (10b) (10c
), and indoor heat exchangers (6a) (6b) (6c)
One of the indoor switching valves (15a) (15b) (15c)
and close the other indoor switching valve (16a) (16b).
) (16c), the refrigerant discharged from the compressor (2) is transferred from the discharge pipe (7) to the switching valve (9a) (9
b) (9c), outdoor heat exchanger (3a) (3b) (3c
) and is condensed and liquefied here, the refrigerant flow control valves (18a) (18b) (18c) in the fully open state, and the liquid pipe (14
) to the refrigerant pressure reducers (17a) (17b) (17C) of each indoor unit (5a) (5b) (5c), where the pressure is reduced. After that, each indoor heat exchanger (6a
) (6b) After evaporation in (6c), the indoor switching valves (16a>(16b) (16c), low pressure gas pipe (13), suction pipe (8>), and gas-liquid separator (4) are sequentially connected. After that, it is sucked into the compressor (2). In this way, all the rooms are cooled at the same time by each indoor heat exchanger (6a) (6b) (6c) that acts as an evaporator. Conversely, all the rooms are heated at the same time. If the outdoor heat exchanger (3a
) (3b) One outdoor switching valve (9a) of (3c)
(9b) (9C) and open the other outdoor switching valve (10a) (10b) (10c), and one indoor switching valve (6a) (6b) (6c) of the indoor heat exchanger (6a) (6b) (6c).
By opening 15a), 15b, and 15c and closing the other indoor switching valves, 16a, 16b, and 16c, the refrigerant discharged from the compressor (2) is transferred to the discharge pipe (7).
), the high pressure gas pipe (12) and the switching valve (15a) (
15b) (15c), indoor heat exchanger (6a>(6b>(
6C), and after being condensed and liquefied here, the pressure is reduced in each refrigerant pressure reducer (17a) (17b) (17c) and combined in the liquid pipe (14), after which the refrigerant flow rate in the fully open state is After passing through the control valves (18a) (18b>(18c) and evaporating in the outdoor heat exchangers (3a), (3b), and (3e), the switching valves (10a) (10b>(10c), the suction pipe (8>),
It passes through the gas-liquid separator (4) in sequence and is sucked into the compressor (2). In this way, each indoor heat exchanger (6
When a>(6b)(6c), all rooms are heated at the same time.

During such cooling and heating operations, for example, the indoor unit (
5b> turns off the thermostat, cooling or heating operation stops, and the cooling or heating load decreases, the outdoor switching valve (9b) (1) of the outdoor heat exchanger (3b) is activated by a signal from the controller (21>).
0b) and the refrigerant flow control valve (18b) are closed, this outdoor heat exchanger (3b) stops functioning as an evaporator or condenser, and is operated at an evaporator or condenser capacity commensurate with the cooling or heating load. ．Furthermore, the indoor unit (5C) stops cooling or heating operation, and the indoor unit with the lowest capacity {5
When the cooling operation or heating operation starts only in a), the controller (21
} The outdoor switching valve of the outdoor heat exchanger (3c) (
9c) (10c) and the refrigerant flow control valve (18c) close, this outdoor heat exchanger (3C) also stops functioning as an evaporator or condenser, and at the same time, the outdoor blower (19) becomes the lowest air speed. , If the evaporator capacity or condensing capacity of the indoor heat exchanger (6a) is still small and the heat exchange capacity of the outdoor heat exchanger (3c) is too large, a signal from the controller 21 will cause the outdoor heat exchanger ( The opening degree of the refrigerant flow control valve (18c) provided in the liquid branch pipe (14c) of 3c> becomes smaller, and the flow rate of refrigerant flowing through the outdoor heat exchanger (3c) decreases, and this outdoor heat exchanger (3c) Fine adjustment is made to a small heat exchange capacity commensurate with the low load of cooling or heating of the indoor unit (5 (!)).

In addition, if you want to simultaneously cool two rooms and heat one room at the same time, turn on one of the outdoor switching valves (9) of the outdoor heat exchanger (3c).
c) and open the other outdoor switching valve (10C) and both switching valves (9a) (3b) of the outdoor heat exchanger (3a) (3b).
10a), (9b) (10b), and closes one indoor switching valve (f5b) (15c) of the indoor unit (5b) (5c) for cooling, and closes the other indoor switching valve (16b) ( 16c) and open one indoor switching valve (15a) of the heating indoor unit (5a) and close the other indoor switching valve (L6a), the refrigerant discharged from the compressor (2> Part is the discharge pipe (7),
One outdoor heat exchanger (3c) after passing through the switching valve (9c)
The switching valve (15a) of the indoor unit (5a) that heats the indoor unit through the high pressure gas pipe (12) and the remaining refrigerant flows through the high pressure gas pipe (12).
), flows to the indoor heat exchanger (6a), and is condensed and liquefied in the indoor heat exchanger (6a) and the outdoor heat exchanger (3c).

The refrigerant condensed and liquefied in the heat exchangers (6b) (3b) passes through the liquid pipes (14) to the indoor unit (5a) (
After being depressurized by the refrigerant pressure reducers (17a) (17c) of 5c), it is evaporated and vaporized by the respective indoor heat exchangers (6a) (6c), and then the respective indoor switching valves (16a) (16c)
through the low pressure gas pipe (13), the suction pipe (8),
It passes through the gas-liquid separator (4>) and is sucked into the compressor (2).In this way, the indoor heat exchanger (6a) which acts as a condenser
>, one room is heated, and the other indoor heat exchangers (6b) (6c), which act as evaporators, cool the two rooms.

During such two-room cooling/one-room heating operation, the total capacity of the indoor heat exchanger (6b) (6c) acting as an evaporator is equal to the indoor heat exchanger (6a) acting as a condenser and the outdoor heat. The capacity of the outdoor heat exchanger (3C) is controlled by controlling the speed of the outdoor blower (19) and the opening degree of the refrigerant flow rate control valve (18c) so that the total capacity of the exchanger (3c) corresponds to the total capacity. The cooling load on both or one of the indoor units (5b) (5c) becomes smaller and the outdoor heat exchanger (
When the heat exchange capacity of 3c> is no longer balanced, a signal from the controller (20) closes the outdoor switching valve (9c) and the refrigerant flow control valve (t8c), and also closes the outdoor switching valve (9c).
b) and the refrigerant flow control valve (18b) are opened, and the outdoor heat exchanger (3b), which has a smaller capacity than the outdoor heat exchanger (3c), starts to act as a condenser.Then, the cooling load is further reduced, and the refrigerant If the balance cannot be maintained even if the valve opening degree of the flow rate control valve (1sb) is reduced, a signal from the controller (20) is sent to the outdoor switching valve (9b) and the refrigerant flow control valve (18).
b) closes, and the outdoor switching valve (9a) and refrigerant flow rate control valve (18a) open so that the outdoor heat exchanger (3a), which has a smaller capacity than the outdoor heat exchanger (3b), acts as a condenser. Fine adjustment of the capacity of the outdoor heat exchanger (3a) is performed by controlling the opening degree of the refrigerant flow rate control valve (18a).

Also, when simultaneously cooling one room with an indoor unit (5a) and heating two rooms with indoor units (5b) and (5c), one of the outdoor switching valves of the outdoor heat exchanger (3c) ( 10c) and open the other outdoor switching valve (9a) (
9b) (9c) (10a) (10b) and one indoor side switching valve (1) of the indoor unit (5a) that cools the air conditioner.
5a) and open the other indoor switching valve (16a), and open one of the indoor switching valves (15b) (15c) of the indoor units (5b) and (5c) for heating and open the other indoor switching valve. (16b) and (16c) are closed, the refrigerant discharged from the compression Ja (2) passes through the discharge pipe (7) and the high pressure gas pipe (12) in sequence, and then the indoor switching valve (15b) (1
5c) and the respective indoor heat exchangers (6b) (6c
) is condensed and liquefied. The liquefied refrigerant is depressurized by the refrigerant pressure reducers (17b) and (17c), respectively, and then flows into the liquid pipe (14), and a part of the liquid refrigerant in the liquid pipe is transferred to the indoor heat exchanger (6a). In addition, the remaining liquid refrigerant passes through the refrigerant flow control valve (18c) in a fully open state, is evaporated in the outdoor heat exchanger (3c), and passes through the suction pipe (8) and the gas-liquid separator 4) in order to the compressor ( 2) is inhaled.

Indoor heat exchanger (6b) that acts as a condenser in this way
Two rooms are heated by (6c), and one room is cooled by another indoor heat exchanger (6a), which acts as an evaporator. During such one-room cooling and two-room heating operation, it acts as a condenser. The outdoor heat exchanger (6a) acting as an evaporator and the outdoor heat exchanger (3c) correspond to the total capacity of the indoor heat exchanger (sb) (6c). The capacity of 3C> is controlled by the speed control of the outdoor blower (19>) and the valve opening control of the refrigerant flow rate control valve (18c), but the heating load of both or one of the indoor units {5b} (5c) becomes smaller. When the heat exchange capacity of the outdoor heat exchanger (3c) becomes unbalanced, the controller (20
The outdoor switching valve (9c) and refrigerant flow control valve (18c) are closed by the signal from The outdoor heat exchanger (3b), which has a small capacity, begins to act as an evaporator.Then, as the heating load becomes smaller and balance cannot be maintained even if the opening degree of the refrigerant flow control valve (18b) is reduced, the control The outdoor switching valve (9b) and the refrigerant flow control valve (18b) are closed by the signal from the outdoor switching valve (9a) and the refrigerant flow control valve (18).
a) is opened, and the outdoor heat exchanger (3a), which has a smaller capacity than the outdoor heat exchanger (3b), comes to act as an evaporator, and fine adjustment of the capacity of this outdoor heat exchanger (38) is made by adjusting the refrigerant flow rate. This is performed by controlling the opening degree of the control valve (18a).In the above embodiment, three refrigerant flow rate control valves (18a) (1
8b) (18c), but a refrigerant flow control valve (
18a> may be provided. In addition, 3 indoor units (5
a> (5b) (5c) were used, but there were 8 units with capacities such as 1 horsepower, 1.25 horsepower, 1.6 horsepower, 2 horsepower, 2.5 horsepower, 3 horsepower, 4 horsepower, and 5 horsepower. In this case, the outdoor heat exchanger (3a) with the minimum capacity of 1.5 to 2 horsepower is suitable. In addition, the switching valve (9a) (10a
), (9b) (10b), (9c) (10c). (
15a) (16a). (15b) (16b) , (1
5c) and (16c), but instead of these, the switching valves (9a) and (10a) were changed to three-way valves, and the switching valve (9b
) (10b) may be used as a three-way valve, for example, a total of six three-way valves.

(g) Effects of the invention In the present invention, the inter-unit piping that connects the outdoor unit and the plurality of indoor units/coolers is composed of three refrigerant pipes: a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe. Therefore, you can combine any number of indoor units by simply branching and connecting them to the inter-unit piping, and you can freely perform simultaneous cooling and heating operations with any indoor unit, as well as simultaneous cooling and heating operations of multiple indoor units. This can be done selectively, and since the indoor heat exchanger that acts as a condenser and the indoor heat exchanger that acts as an evaporator are connected in series during simultaneous heating and cooling operation, efficient operation is achieved through heat recovery. be able to.

Furthermore, by opening and closing the switching valves connected to multiple outdoor heat exchangers according to the size of the heating and cooling load, the capacity of the outdoor heat exchanger can be adjusted, and the capacity can be finely adjusted between the outdoor heat exchangers and the outdoor heat exchanger. Since this is carried out by the refrigerant flow rate control valve of the connected liquid branch pipe, the capacity of the outdoor heat exchanger is linearly controlled, making it possible to obtain heating and cooling capacity commensurate with the heating and cooling load.

[Brief explanation of drawings]

The drawing is a refrigerant circuit diagram of a heating and cooling system showing an embodiment of the present invention.

Claims (1)

[Claims] 1. In an air conditioning system in which an outdoor unit containing a compressor and a plurality of outdoor heat exchangers is connected to a plurality of indoor units containing indoor heat exchangers by inter-unit piping,
One end of each of the plurality of outdoor heat exchangers is branch-connected to a refrigerant discharge pipe and a refrigerant suction pipe of the compressor via a switching valve,
The inter-unit piping is connected to a high-pressure gas pipe branch-connected to the discharge pipe, a low-pressure gas pipe branch-connected to the suction pipe, and the other ends of the plurality of outdoor heat exchangers via liquid branch pipes. 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 other end of each indoor heat exchanger is connected to the liquid pipe for refrigerant depressurization. 1. An air-conditioning and heating apparatus, characterized in that the liquid branch pipes are connected to each other via a refrigerant flow control valve, and at least one of the liquid branch pipes is provided with a refrigerant flow rate control valve.