JPH0285656A - Airconditioner - Google Patents

Abstract

PURPOSE:To make it possible to select freely cooling or heating operation in each room by designing an airconditioner which allows a capacity variation of a capacity variable type compressor and effects switch over of an outdoor side change over valve, conforming to the temperature of each indoor heat exchanger or the pressure of refrigerant or the temperature of air blowoff for a indoor unit where cooling or heating operation is being carried out. CONSTITUTION:For example, when an indoor side change over valve for indoor units 5a and 5c to be cooled are set to cooling state, while an indoor side change over valve for an indoor unit 5b to be heated are set to heating state at the same time, a part of refrigerant discharged from a capacity variable type compressor flows only to a paired outdoor heat exchanger 3a while the rest of the refrigerant flows to an indoor heat exchanger 6b for the indoor unit 5b to be heated by way of a high pressure pipe 12, and get condensed and liquefied by this heat indoor heat exchanger and an outdoor heat exchanger 3b. The refrigerant is distributed to a pressure reducing device for each indoor unit 5a, and 5c to be cooled by way of a liquid pipe 14. Then, it is vaporized in each indoor heat exchanger 6a, and 6c, and absorbed into the compressor 2 by way of a low pressure gas pipe 13.

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, cooling one room at the same time, etc. The present invention relates to a multi-room air conditioner that heats a room.

(B) Prior art A multi-room air conditioner that can cool or heat all of multiple rooms at the same time, and that can simultaneously cool one room and heat the other rooms, is disclosed in Japanese Patent Publication No. 52-24710 and Japanese Patent Publication No. 52-24710. 52-2
This method is disclosed in Japanese Patent Publication No. 4711, Japanese Patent Publication No. 52-27459, and Japanese Utility Model Publication No. 3020-1983.

(c) Problem to be solved by the invention The above-mentioned Japanese Patent Publication No. 52-24710 and Japanese Patent Publication No. 52-
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. Furthermore, 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 impossible to recover heat. There was a problem.

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 cools multiple rooms and heats other rooms at the same time, the combination of rooms that can be cooled and rooms that can be heated is determined, and air conditioning operation can be performed freely in each room. This method has the disadvantage that it is not easy to use and cannot be used selectively.

An object of the present invention is to provide a multi-room air conditioner that solves the above-mentioned problems.

(D) Means for Solving the Problems The present invention connects a plurality of outdoor heat exchangers to a refrigerant discharge pipe and a refrigerant suction pipe of a variable capacity compressor through outdoor switching valves, respectively. The inter-unit piping that connects the unit and multiple indoor units includes a high-pressure gas pipe that is branch-connected to the refrigerant discharge pipe of the compressor, a low-pressure gas pipe that is branch-connected to the refrigerant suction pipe of the compressor, and multiple It consists of an outdoor heat exchanger and a connected liquid pipe, and the indoor heat exchanger of each indoor unit is branch-connected to a high-pressure gas pipe and a low-pressure gas pipe via an indoor switching valve, and the refrigerant is depressurized to the liquid pipe. connect through the device,
Variable capacity of the variable capacity compressor and switching of the outdoor switching valve according to the indoor heat exchanger temperature, refrigerant pressure, or air blowing temperature of the indoor unit in cooling operation and the indoor unit in heating operation. The apparatus is equipped with a capacity control means for performing the following.

(*) Effect When cooling all rooms at the same time, the outdoor switching valve of each outdoor heat exchanger and the indoor switching valve of each indoor heat exchanger are set to the cooling state. The refrigerant discharged from the discharge pipe flows in parallel to each outdoor heat exchanger, where it is condensed and liquefied, and then distributed to the refrigerant pressure reducer of each indoor unit via liquid pipes. After being evaporated, it passes through a low-pressure gas pipe and a refrigerant suction pipe in sequence and is sucked into a variable capacity compressor. In this way, all rooms are cooled by each indoor heat exchanger acting as an evaporator.

During such cooling operation, when the temperature of each indoor heat exchanger is 2°C or higher, the variable capacity compressor is operated at a capacity that matches the compression function required by each indoor unit. When the temperature drops below 2°C, the compressor capacity is prohibited from increasing, and when the temperature still falls below O''C, the compressor capacity is reduced to prevent each indoor heat exchanger from freezing.

In addition, when heating all rooms at the same time, the outdoor switching valve of each outdoor heat exchanger and the indoor switching valve of each indoor heat exchanger are set to the heating state, thereby reducing the discharge from the variable capacity compressor. The refrigerant is distributed to each indoor heat exchanger through a discharge pipe and a high-pressure gas pipe, where it is condensed and liquefied, passed through each refrigerant pressure reducer, and combined in a liquid pipe, and then transferred to each outdoor heat exchanger. The refrigerant is passed through the refrigerant in parallel to the refrigerant, where it evaporates and vaporizes, and then is sucked into the compressor through the refrigerant suction pipe. In this way, all rooms can be heated with each indoor heat exchanger acting as a condenser.

During such heating operation, when the temperature of each indoor heat exchanger is 58°C or less, the variable capacity compressor is operated at a capacity that matches the compression function required by each indoor unit. When the temperature rises above 58°C, the capacity of the compressor is prohibited from increasing, and when the temperature rises further above 60°C, the capacity of the compressor is reduced to prevent the high pressure from rising abnormally.

Also, when simultaneously cooling two units and heating one room, the outdoor switching valve of one outdoor heat exchanger is set to the cooling state, and the outdoor switching valve of the other outdoor heat exchanger is set to the cooling state. When the indoor switching valve of the indoor unit that closes and cools is set to the cooling state, and the indoor switching valve of the indoor unit that heats the air is set to the heating state, part of the refrigerant discharged from the variable capacity compressor is closed. Part of the refrigerant flows only to the outdoor heat exchanger of -Fj, and the remaining refrigerant flows through the high-pressure gas pipe to the indoor heat exchanger of the indoor unit to be warmed, and is condensed and liquefied in this indoor heat exchanger and the outdoor heat exchanger. Ru. The refrigerant condensed and liquefied in these heat exchangers is distributed through liquid pipes to the refrigerant pressure reducers of each indoor unit that cools the room, and then evaporated in each indoor heat exchanger. The air is drawn into the variable capacity compressor through the suction pipe. 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.

During such simultaneous cooling and heating operation, when the temperature of the indoor heat exchanger of the cooling operation unit is 2°C or higher and the temperature of the indoor heat exchanger of the heating operation unit is 588C or lower, the compression function required by the cooling operation unit is The variable capacity compressor is operated at a capacity commensurate with this large capacity by comparing the compression function power required by the heating operation unit, but when this temperature condition is not met, the cooling operation unit and heating operation unit are Either the capacity of the outdoor heat exchanger is controlled according to the temperature of each indoor heat exchanger, the capacity of the compressor is prohibited from increasing, or the capacity of the compressor is lowered. Freezing of the heat exchanger and abnormal rise in high pressure are prevented.

(f) Example A first example of the present invention will be explained based on FIG.
1) is an outdoor unit (5a) (5) having a variable capacity compressor (2) whose operating frequency can be changed by an inverter, an outdoor heat exchanger (3a) (3b), and a gas-liquid separator (4).
b) (5c) is an indoor heat exchanger (6a) (6b) (6c)
In an indoor unit having an outdoor heat exchanger (3a) (3b
) to the refrigerant discharge pipe (7) and refrigerant suction pipe (8) of the variable capacity compressor (2), and the outdoor switching valves (9a) (10a),
(9b) (10b), while outdoor unit 1-(1) and indoor unit (5a) (5b) (5
c), and a high pressure gas pipe (12) branch-connected to the refrigerant discharge pipe (7), and a low-pressure gas pipe (13) branch-connected to the refrigerant suction pipe (8). , liquid pipes (14) connected to outdoor heat exchangers (3a) (3b)
and each indoor heat exchanger (6a) (6b) (6c
), the high pressure gas pipe (12) and the low pressure gas pipe (13) are equipped with indoor switching valves (15a), (16a), (15b), respectively.
(16b), (15c bar 16C), and is connected to the liquid pipe (14) via refrigerant pressure reducers (17a), (17b), and (17c) such as electric expansion valves.

(18) is a bypass pipe that connects the high-pressure gas pipe (12) and the liquid pipe (14), and provides refrigerant flow resistance with a capillary duplex (19).

(207 is a vapor pressure regulating valve installed in the low pressure gas pipe (13), (21a) (21b) is an auxiliary refrigerant pressure reducer such as an electric expansion valve installed in the liquid pipe (14), (22M) (22b) is an outdoor blower, and (23a), (23b), and (23c) are indoor blowers.

(24a), (24b), and (24c) are air conditioning/heating switching means;
Room temperature sensor (25a) (25b) (25c) measures the temperature in the room where each indoor unit (5a) < 5b) (5c) is installed.
), and if the detected temperature exceeds the set temperature, a cooling command is issued, and conversely, if it falls below the set temperature, a heating command is issued, and the respective indoor switching valves (15a), (16a), (15b)
)(16b), (15c), and (16c), and also controls the rotational speed of the indoor blowers (23a), (23b), and (23c). In addition, (26) is a capacity control means that detects the temperature of the indoor heat exchangers (6a) (6b) (6c) with sensors (27a) (27b) (27c) and controls the temperature as shown in the road map in Fig. 2. When the temperature of the indoor heat exchanger of the cooling operation unit is 2°C or higher and the temperature of the indoor heat exchanger of the heating operation unit is 58°C or lower, the compression function required by the cooling operation unit and the heating operation are The compression function required by the unit and the heating/cooling switching means (24a
) (24b) and (24c) to compare the two capacities and operate the capacity i7 modified compressor (2) at the capacity corresponding to this large capacity.If this temperature condition is not satisfied, the cooling operation unit 1 is operated. - and the outdoor switching valve (9a) (10a) depending on the temperature of each indoor heat exchanger of the heating operation unit.
, (9b) (10b) to open and close the outdoor heat exchanger (3
a) Control the presence of (3b) or use a variable capacity compressor (
2) either prohibits the capacity from increasing or reduces the capacity of the variable capacity compressor (2), and controls the rotational speed of the outdoor blowers (22a) (22b). be.

Next, the driving operation will be explained based on the road map shown in FIG. 2 and the flowchart shown in FIG. 3. All indoor units (5a
) (5b) (5c) Air conditioning/heating switching means (24a) (24
b) When a cooling command is issued from (24c), one of the indoor switching valves (15a) (15b) (15c) closes, and the other indoor switching valve (L6a) (16b) (16c) closes.
) open and the respective indoor fans (20a)<20b)
(20c) is started, and the heating/cooling switching means (24
a) The capacity control means (26) inputs the cooling signals from (24b) and (24c) to provide the compression function power (for example, operating frequency of 25 Hz) required by the indoor unit (5a) and the required power by the indoor unit (5b). Variable capacity compression (operating frequency 95Hz) that matches the sum of compression functional power (eg λ, operating frequency 3011 z) and compressing functional power required by the indoor unit (5c) (eg operating frequency 40 Hz)! At the same time as (2) is operated, the outdoor blowers (22a) (22b) are operated, and one outdoor switching valve (9a) (9b) opens and the other outdoor switching valve (10a) (10b) closes. As a result, the refrigerant discharged from the variable capacity compressor (2) sequentially flows through the discharge pipe (7), the outdoor switching valve (9g) (9b), and the outdoor heat exchanger (3a) (3b). After condensing and liquefying, it passes through the liquid pipe (14) to each room neat (5a).
) (5b) (5c) refrigerant pressure reducer (17a) (17b)
(17C), where it is depressurized. After that, after being evaporated in each indoor heat exchanger (6a) (6b) (6c), the indoor switching valve (16a) (16b) (16c) is
), low pressure gas pipe (13), suction pipe (8), gas-liquid separator (
4) and is sucked into the variable capacity compressor (2).

Each indoor heat exchanger (6a
) (6b) All rooms are cooled at the same time in (6c). still,
The refrigerant may be depressurized using auxiliary refrigerant pressure reducers (21a) (21b) instead of the refrigerant pressure reducers (17a), (17b), and (17c).

During such simultaneous cooling operation, the refrigerant discharged from the variable capacity compressor (2) is transferred from the high pressure gas pipe (12) to the bypass pipe (1).
8) to the liquid pipe (14), so the high pressure gas pipe (
11) Refrigerant and lubricating oil will not accumulate in the tank. still,
One end of the bypass pipe (18) may be connected to the high pressure gas pipe (12), and the other end may be connected to the low pressure gas pipe (13).

Also, during such simultaneous cooling operation, for example, indoor: I-knit (
When the indoor temperature in 5b) or (5c) reaches the set temperature and the cooling operation is stopped by a stop signal from the heating/cooling switching means (24b) or (24c) and the cooling load becomes small, the operating frequency of the variable capacity compressor (2) changes. is lowered to 65Hz or 55Hz and operated at low capacity.

In this way, during cooling operation, when the temperature of each indoor heat exchanger is in the A zone of 2°C or higher as shown in Figure 2, the capacity variable compressor is operated with a capacity that matches the compression function required by each indoor unit. (2) is operated, but the temperature of each indoor heat exchanger is 2.
When the temperature drops below 0°C and enters the B zone, the capacity of the IE compressor 2) is stopped from increasing, but when the temperature drops further below 0°C and enters the C zone, the capacity of the compressor (2) is reduced -C Prevents each indoor heat exchanger from collapsing.

Conversely, when a heating command is issued from the air conditioning/heating switching means (24a) (24b) (24c) of all the indoor units (5a) (5b) (5c), one of the indoor switching valves (15a) (15
b) (15c) opens and the other indoor switching valve (16
a) (16b) (16c) are closed, and the heating signal from the air conditioning/heating switching means (24a) (24b) (24c) is input to the capacity control means (26), and the indoor unit l-(5g)
The compression function power required by the indoor unit (for example, 30 Hz operating frequency), the compression function power required by the indoor unit (5b) (for example, the operation frequency 3.511 z), and the compression function power required by the indoor unit (5c)
The variable capacity compressor (2) is operated at a capacity (operating frequency 110 Hz) corresponding to the sum of the compression functional power (for example, operating frequency 45 Hz) required by Other outdoor switching valve <10a)
(lffb> opens, variable capacity compressor (2
) The refrigerant discharged from the discharge pipe (7) and the high pressure gas pipe (1
2) and then the indoor switching valve (15a>(15b)(1
5c), indoor heat exchangers (6a>(6b) (6c), where each refrigerant is condensed and liquefied, and then transferred to each refrigerant pressure reducer (1
7a) (L7b) (17c) or auxiliary refrigerant pressure reducer (
21a) (21b) and are combined in the liquid pipe 14), then evaporated in the outdoor heat exchanger (3a) (3b), and then transferred to the outdoor switching valve (LOa) (10b) and the suction It passes through a pipe 8) and a gas-liquid separator (4) in order and is sucked into a variable capacity compressor (2). In this way, all the rooms are heated simultaneously by each indoor heat exchanger (6a>(6b)(6c)) acting as a condenser.

During such heating operation, for example, the indoor unit (5b) or (
5c) When the indoor temperature reaches the set temperature, the heating/cooling switching means (
When the heating operation is stopped by the stop signal of 24b) or (24c), the operating frequency of the variable capacity compressor 2) is lowered to 75Hz or 65Hz by a signal issued from the capacity control means (2G), and the operation can be performed at a low capacity. .

In this way, during heating operation, when the temperature of each indoor heat exchanger is in the A zone of 58°C or less as shown in Figure 2, the capacity variable compressor is operated at a capacity that matches the compression function required by each indoor unit. (2) is operated, but when the temperature of each indoor heat exchanger rises above 58°C and enters the D zone, the capacity of compressor (2) is prohibited from increasing, and even then the temperature rises above 60°C. When entering the E zone, the capacity of the compressor (2) is reduced to prevent the high pressure from rising abnormally.

In addition, when cooling two units and heating one room at the same time, for example, when a cooling command is issued from the air conditioning/heating switching means (24a) (24c) of any two indoor units (5a) (5c), the respective indoor units When the switching valves (15a) (15c) are closed and the other indoor switching valve (16a) (15c) is opened, and a heating command is issued from the air conditioning/heating switching means (24b) of one indoor unit (5b), one indoor switching valve (15b
) opens and the other indoor switching valve (16b) closes,
Moreover, the compression l! required by the indoor unit (5a) operated for cooling! (operating frequency 65)12)
and the compression function power (for example, operating frequency 50 Hz) required by the indoor unit (5b) to be operated for heating, and determine the capacity (operating frequency 65) that corresponds to this large capacity on the cooling side.
A control signal is issued from the capacity control means (26) so that the variable capacity compressor (2) is operated at 1z), and
The signal from this capacity control means (26)
II switching valve (9a) opens and the other outdoor switching valve (9b)
(10a) and (10b) are closed, a portion of the refrigerant discharged from the variable capacity compressor (2) is discharged from the discharge pipe (7).
), the indoor switching valve of the indoor unit (5b) that sequentially switches the outdoor switching valve (9a) to flow only to one outdoor heat exchanger (3a), and the remaining refrigerant passes through the high-pressure gas pipe (12) for heating. (15b), flows to the indoor heat exchanger (6b), and is condensed and liquefied in the indoor heat exchanger (6b) and the outdoor heat exchanger (3a). And these heat exchangers (6b) (3
The refrigerant condensed and liquefied in a) passes through the liquid pipe (14) to the refrigerant pressure reducer (17a) (17) of the indoor unit (5a) (5c).
After the pressure is reduced in c), the respective indoor heat exchangers (6a) (6
c), and then each indoor switching valve (16a
) (16c), the gas flows through the low-pressure gas pipe (13), passes through the suction pipe (8) and the gas-liquid separator (4) in sequence, and is then sucked into the variable capacity compression type Ja (2). In this way, the indoor heat exchanger (6b) acting as a condenser heats the room, and the other indoor heat exchangers (6a) and (6c) acting as evaporators cool the two rooms.

In addition, if such simultaneous heating and cooling operation is performed in the summer when the outside air temperature is high, even if the outdoor heat exchanger (22a) is rotated at high speed, the outdoor heat exchanger (3a) alone will not be able to sufficiently dissipate heat to the outside air, and the indoor heat will increase. When the temperature of the exchanger (6a) (6c) exceeds 2°C and enters the F zone where the cooling capacity decreases, the outdoor switching valve (9b) opens in response to a signal from the capacity switching means (26) and the discharge pipe After a part of the refrigerant discharged from (7) flows to the other outdoor heat exchanger (3b) and is condensed and liquefied,
The refrigerant passes through the auxiliary refrigerant pressure reducer (21b) and merges into the liquid pipe (14), and the outdoor heat exchanger (3b), which acts as a condenser, further dissipates heat to the outside air to prevent a decrease in cooling capacity. do. Additionally, during this summer operation, when the indoor temperature of the indoor unit (5c) reaches the set temperature and the cooling operation is stopped by a signal from the air conditioning/heating switching means (24c), and the cooling load decreases, the room temperature that is being cooled is The compression function required by unit h (5a) (for example, the operating frequency 2
5Hz) and the compression function power (for example, operating frequency 501 (z)) required by the indoor unit (5b) in heating operation to determine whether the heating capacity (operating frequency 50) 1z corresponds to the large capacity of heating (11). A control signal is issued from the capacity control means (26) so that the capacity variable compression type m(2) is operated.

In addition, when such simultaneous heating and cooling operation is performed in winter, the indoor heat exchanger (6a) (
The refrigerant pressure in 6c) tends to drop below 4kg/cm'', but this pressure drop is prevented by the action of the evaporation pressure regulating valve (20), and the indoor heat exchangers (6a) and (6c) are prevented from freezing. No. In addition, the evaporation pressure regulating valve (20) is installed in each switching valve (16a) (16) instead of being installed in the low pressure gas pipe (13).
b) Pipe (28) between (16c) and low pressure gas pipe (13)
They may be provided in a) (28b) and (28c), respectively. Also, instead of providing the evaporation pressure regulating valve (20), an indoor heat exchanger (
Refrigerant pressure in 6a) (8c) is 4 kg/am'
When the temperature drops to below, the refrigerant is matured by reducing the opening of the refrigerant pressure reducer (17a) (17c) and this heat is used to prevent freezing, and when the freeze is lifted, the refrigerant pressure reducer (17a) (
The opening degree of 17c) may be returned to its original value.

Next, when cooling one room and heating two units, it is possible to operate the auxiliary refrigerant pressure reducer (21a). For example, the heating/cooling switching means (24a) of any two indoor units (5a) (5c) ) (24c), the indoor switching valves (15a) (15c) open, the other indoor switching valve (tea) (16c) closes, and
Heating/cooling switching means (24b) for the indoor unit (5b)
When a cooling command is issued from
b) closes, and the other indoor switching valve (16b) opens, and one indoor unit (5c) that is in heating operation has the compression function required (for example, an operating frequency of 451 pupil) and one indoor unit (5c) that is in heating operation. ) required compression function power (for example, operating frequency 40 Hz) (operating frequency 85 Hz)
and the compression function power (for example, operating frequency 35H2) required by the indoor unit (5b) to be operated for cooling.
A control signal is issued from the capacity control means (26) so that the capacity variable compressor (2) is operated at ) opens and the other outdoor switching valve (9a) (9b
)(10b) closes.

Therefore, the refrigerant discharged from the variable capacity compressor (2) passes through the discharge pipe (7) and the high-pressure gas pipe (12) in order and is distributed to the indoor switching valves (15a) and (15c) for indoor heat exchange. It is condensed and liquefied in vessels (6a) and (6c). Then, this liquefied refrigerant is transferred to a fully opened refrigerant pressure reducer (17a).
A part of the liquid refrigerant in this liquid pipe is depressurized by the refrigerant pressure reducer (17b), and then the remaining liquid refrigerant is auxiliary by the indoor heat exchanger (6b). After being depressurized by the refrigerant pressure reducer (21a), the refrigerant is evaporated and vaporized by the outdoor heat exchanger (3a), and is sucked into the variable capacity compressor (2) through the suction pipe (8) and the gas-liquid separator (4). be done.

Indoor heat exchanger (6a) that acts as a condenser in this way
(6c) heats the two rooms, and another indoor heat exchanger (6b), which acts as an evaporator, cools the room.

If such simultaneous heating and cooling operation is performed in winter when the outside air temperature is low, even if the outdoor fan (22a) is rotated at high speed, the outdoor heat exchanger (3a) alone cannot draw enough heat from the outside air, and the indoor heat exchanger (6a) is turned off. (6c) temperature is 58°C
When entering the G zone where the heating capacity decreases, the outdoor switching valve (10b) is activated by a signal from the capacity control means (26).
When the auxiliary refrigerant pressure reducer (21b) opens, the other outdoor heat exchanger (3b) also acts as an evaporator.
A decrease in heating capacity is prevented.

In addition, during this winter operation, for example, if the indoor unit (5
c) When the indoor temperature reaches the set temperature, the heating/cooling switching means (2)
When the heating operation is stopped by the signal 4c), the compression function power required by the indoor unit (5a) in heating operation (for example, operating frequency 45 Hz) and the compression function power required by the indoor unit (5b) in cooling operation are changed. (e.g. 35Hz)
A control signal is issued from the capacity control means (26) so that the variable capacity compressor (2) is operated at a capacity (operating frequency of 45 Hz) corresponding to the large capacity of the heating side.

Moreover, when such simultaneous heating and cooling operation is performed in the middle of spring and autumn, the indoor heat exchanger (6b) functioning as an evaporator
When the temperature of the outdoor fan (
22a) switches from high-speed operation to low-speed operation and then stops operation to reduce the amount of heat pumped from the outside air and prevent the cooling capacity from decreasing, but if the cooling capacity decreases further, the outdoor switching valves (9a) (10a) ) to connect the outdoor heat exchanger (3a
) acts as a condenser.

Further, when the temperature of the indoor heat exchanger operating for cooling and the temperature of the indoor heat exchanger operating for heating enter the H zone, the capacity of the variable capacity compressor (2) is prohibited from increasing; Even so, when entering the I zone, the capacity of the compressor (2) is reduced to prevent each indoor heat exchanger that is cooling the room from freezing, and the temperature of the indoor heat exchanger that is heating the room is detected to reduce the high pressure. Abnormal rise is prevented.

In this way, each indoor unit (5a) (5b) (5c
), the automatic heating and cooling operation is optionally activated by the room heating command, and the outdoor heat exchanger (3g) (3b) is operated as a condenser or an evaporator by the capacity switching means (26) depending on the size of the heating and cooling load. Each indoor heat exchanger (6a) (6b) functions as an evaporator and a condenser during simultaneous cooling and heating operation.
) (6c) heat recovery is performed to further improve operational efficiency.

In addition, when the outdoor heat exchangers (3a) (3b), which act as evaporators during all-room heating operation, become frosted, the capacity switching means (
26), one outdoor switching valve (9a) is opened and the other outdoor switching valve (10a) is closed, and one of the high-temperature discharge refrigerant is discharged from the discharge pipe (7) to one outdoor heat exchanger (3a). The outdoor heat exchanger (3a) is defrosted by introducing the outside heat exchanger (3a), and then one of the outdoor side switching valves (9a) is closed and the other outdoor side switching valve (10a) is opened to defrost the outdoor heat exchanger (3a). The outdoor heat exchanger (3a) is made to function as an evaporator again, and the outdoor switching valve (9b) is opened and the outdoor switching valve (10b) is closed to connect the discharge pipe (7) to the other outdoor heat exchanger (3b). ), the outdoor heat exchanger (3b) is defrosted by introducing a part of the high-temperature discharge refrigerant from ), and the outdoor heat exchanger (3a) and (3b) are alternately defrosted while heating operation is performed in all rooms. It is carried out continuously.

In addition, for simultaneous heating and cooling operation in which one of the outdoor heat exchangers (3a) (3b) acts as an evaporator and the other stops working,
One outdoor heat exchanger (3a) acting as an evaporator
When frost forms on the outdoor heat exchanger (3a), one of the outdoor switching valves (9a) (10a) is switched by a signal from the capacity switching means (26) to defrost the outdoor heat exchanger (3a), and at the same time, the other outdoor switching valve ( 9b) (10b) to connect the outdoor heat exchanger (3b)
) acts as an evaporator to continue simultaneous heating and cooling operations.

Also, during the above-mentioned all-room cooling operation, for example, the indoor unit (5b
) to heating operation, use the indoor switching valve (15
b) (16b) and close both refrigerant pressure reducers (17
b) Open the indoor heat exchanger (6b) in advance.
After increasing the internal refrigerant pressure, opening the indoor switching valve (15b) suppresses refrigerant noise caused by the refrigerant pressure difference.

Similarly, during all-room heating operation, for example, the indoor unit (5b)
When switching only the indoor side switching valve (
15b) and the refrigerant pressure reducer (17b) and slightly open the other indoor switching valve (16b) to forcibly lower the refrigerant pressure in the indoor heat exchanger (6b), or after this indoor switching valve is closed. By closing the valve (16b) and opening the indoor switching valve (16b) after the refrigerant pressure in the indoor heat exchanger (6b) has naturally decreased, the generation of refrigerant noise due to the refrigerant 1:E force difference can be prevented. .

In addition, in order to slightly open the indoor switching valve (16b), an expensive electric valve with adjustable opening is used as the switching valve (16b), so the indoor switching valve (16b) and other indoor switching valves are If a bypass capillary tube for pressure relief is provided in parallel with the valves (16a) (16c), the indoor switching valve (16a)
(16b) A simple on-off valve can be used as (16c).

Further, in the above embodiment, indoor heat exchangers (6a) (6b) (6
The temperature of c) is detected by the sensor (27a) < 27b) (27c), but instead, the temperature is cooled or heated by the refrigerant pressure of the indoor heat exchanger or the indoor heat exchanger, which has a correlation with this temperature. It is also possible to detect the air blowing temperature.

Fig. 4 shows a second embodiment of the present invention, in which indoor switching valves (15c) (16c) are used when the indoor unit (5c) is installed in a year-round cooling room such as a computer room. Zuni,
The indoor heat exchanger (6c) is directly connected to the low pressure gas pipe (13), and the same reference numerals as in the first embodiment are used to omit detailed explanation.

FIG. 5 shows a third embodiment of the present invention, in which when the indoor heat exchanger (6c) is used for year-round heating or hot water supply, it is possible to directly , an indoor heat exchanger (6c) is connected to a high-pressure gas pipe (12), and the same reference numerals as in the first embodiment are used (=J), and detailed explanation will be omitted.

FIG. 6 shows a fourth embodiment of the present invention, in which an indoor unit (5a) is installed in an unspecified room, and other indoor units <5b) (5c) are installed in a specific large room. The indoor switching valve (15b) of the unit (5b) (5c)
) (16b) to control the heating and cooling operation of the indoor unit (5a).
This is done by switching the indoor units (5b) and (5).
The heating and cooling operation of c) is performed simultaneously using the indoor switching valves (15b and 16b), and the same reference numerals as in the first embodiment will be used and detailed explanation will be omitted.

FIG. 7 shows a fifth embodiment of the present invention, in which the pipes in each indoor unit (5a), (5b), and (5c) are connected as shown, and the indoor switching valves (15g), (16a), ( 1
5b) (16b).

(15c) (16c), and refrigerant pressure reducer (17a) (1
7b) (17c), and check valves (28a) (28b)
(28c), and when cooling, the liquid pipe (14)
The liquid refrigerant from the refrigerant pressure reducer (17a) (17b) (17
After IE reduction in c), indoor heat exchanger (6g) (6b)
(6c) - Indoor side switching valve (16″a) (16b) (16
c) -The gas refrigerant flows through the low-pressure gas pipe (13), and during heating, the gas refrigerant from the high-pressure gas pipe (12) passes through the indoor switching valve (15a) (
15b) (15c) - Indoor heat exchanger (6a>(6b)(
6c) - Check valve <29a) (29b) (29c) - Liquid pipe (14) is the same as in the first embodiment except that it flows,
The same reference numerals are used to omit detailed explanation.

FIG. 8 shows a sixth embodiment of the present invention, in which each indoor heat exchanger (6a) (6b) (6c) is connected to the first heat exchanger (6c).
1a) (6th) (6tc) and second heat exchange '1k (6
2a), (62b), and (62c), and a dehumidifying refrigerant pressure reducer (30g) such as an electric expansion valve is installed between this internal heat exchanger.
, ) (30b) and (30c), and during cooling, the liquid refrigerant from the liquid pipe (14) flows through the refrigerant pressure reducer (17a)
17b) After being depressurized in (17c), the first heat exchanger (
61a) (61b) (61c) - Fully open dehumidifying refrigerant pressure reducer (30a) (30b) (30c) - Second heat exchanger (62a) (a2b) (62c) - Indoor switching valve (16
a) (16b) (16c) and the first. Second heat exchanger (61a) (62a), (
61b) (62b), (61c) and (62c), respectively. On the other hand, during heating, the gas refrigerant from the high-pressure gas pipe (12) flows through the indoor switching valve (15a) < 15b) (15
c) -Second heat exchanger (62a) (62b) (62c)-
Dehumidifying refrigerant pressure reducer (30a) (30b) (3
0c) - First heat exchanger (61a) (61b) (61c)
- Refrigerant pressure reducer (17a) (17b) (17c) - Liquid pipe (
13) and acts as a condenser. Second heat exchanger (61a) (132a), (61b) (62b)
, (61c) and (62c) respectively.

Also, during dehumidification, the liquid refrigerant from the liquid pipe (14) passes through the refrigerant pressure reducers (17a) (17b) (17c) in a fully open state - the first heat exchanger (61a) (61b) (61c), and then becomes the dehumidifying refrigerant. After the pressure is reduced by the pressure reducer (30a) (30b) (30c),
The second heat exchanger (62a) (82b) (62c) flows through the indoor switching valve (16a) (16b) (16c) and acts as an evaporator.
The indoor air cooled in step 2C) is reheated and dehumidified in the first heat exchangers (61a, 61b, and 61c) that function as condensers. In addition, the heating and cooling switching means (24a) (24
b) The control operations by (24c) and the capacity switching means (26) are the same as in the first embodiment, so the same reference numerals are given and the explanation will be omitted.

FIG. 9 shows a seventh embodiment of the present invention, in which the negative indoor unit (5a) has indoor switching valves (15a) and (16a).
), cooling operation and heating operation are arbitrarily performed by switching the indoor switching valve (1
5b) (16b), (15c) (16c), indoor heat exchanger (6b) (6c) acts as an evaporator, cooling operation is switched to indoor heat exchanger (6b) (6c).
) acts as a condenser for heating operation, and the indoor heat exchanger (6b) acts as an evaporator for indoor heat exchange! ! ! (6c)
When it acts as a condenser, a dehumidifying operation is performed, and a humidifier (31) is also provided for humidity adjustment.

Note that the control operations by the air-conditioning/heating switching means (24g) (24b) and the capacity switching means (26) are the same as those in the first embodiment, so the same reference numerals are given and the explanation will be omitted.

FIG. 10 shows an eighth embodiment of the present invention, which differs from the first embodiment in that two outdoor units I/(la)(lb) are used, and one outdoor unit 71 to (18) is Variable capacity compressor (2a) with variable compression capacity and outdoor heat exchanger (3a)
and gas-liquid separator (4a) and outdoor I11 switching valve (9a) (
10a) and an auxiliary refrigerant pressure reducer (21a), and the other outdoor unit (lb) is equipped with a constant capacity compressor (2b) whose compression capacity does not change, an outdoor heat exchanger (3b), and a gas-liquid separator ( 4b), outdoor switching valves (9b) (10b), and an auxiliary refrigerant pressure reducer (21b), and each refrigerant discharge pipe (7a buff b) is connected to the high pressure gas pipe (12), and the refrigerant suction pipe (8a ) (8b) is connected to the low pressure gas pipe (13), and as in the first embodiment, the heating/cooling switching means (24G
) (24b) (24c) and capacity switching means (26a) (2
Variable capacity compressor (2a) by control operation by 6b)
Capacity switching, constant capacity compressor (2b) starting/stopping, and switching valves (9a) (IQa), (9b) (10b),
By opening and closing (15a), (16a), (15c)<16c), all-room cooling operation, all-room heating operation, and simultaneous cooling/heating operation can be performed.

In each of the above embodiments, two or three indoor units (5a), (5b), and (5c) were used, but even in the case of four or more indoor units with different capacities, the inter-unit piping (11) The number of outdoor heat exchangers or the number of outdoor units can be easily increased by connecting the outdoor heat exchangers or outdoor units in a branched manner according to the number of indoor units. In addition, the variable capacity compressor (2) (2a) is connected to the outdoor heat exchanger (3).
It may be provided in an outdoor unit separate from the bar 3b). In addition, as the variable capacity compressor (2) (2a), in addition to the frequency conversion type, a maximum conversion type compressor, an unloader type compressor, etc. may be used.

In addition, in each of the above embodiments, the switching valves (9g) (10a),
(9b) (10b), (15a) (16a),
Two-way valves were used for (15b), (16b), (15c), and (16c), respectively, but instead of these, switching valves (9a) (
A total of five three-way valves may be used, such as 10a) being a three-way valve and switching valves (9b) and (10b) being three-way valves.

Further, in the above embodiment, a plurality of outdoor heat exchangers (3a) (3
b) was formed separately, but these outdoor heat exchangers (3a)
(3b) may be formed integrally.

(G) Effects of the Invention In the present invention, the inter-unit piping connecting the outdoor unit and the plurality of indoor units 71 is composed of three refrigerant pipes: a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe. You can combine any number of indoor units by simply branching them to the inter-unit piping, and you can freely select simultaneous cooling and heating operations for any indoor unit, as well as simultaneous cooling and heating operations for multiple indoor units. In addition, the temperature of the indoor heat exchanger of the indoor unit in the cooling operation and the indoor unit in the heating operation or the cold tofu pressure gap number 1 can be adjusted according to the air blowing temperature of the variable capacity compressor. By changing the capacity of the indoor heat exchanger and switching the capacity of the outdoor heat exchanger using the capacity switching means, each indoor unit can be operated for cooling or heating at will while preventing the freeze protection IF of the indoor heat exchanger and high pressure from rising abnormally. can do.

Furthermore, during simultaneous heating and cooling operations, 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 achieved through heat recovery.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant circuit diagram of an air conditioner showing a first embodiment of the present invention, Fig. 2 is a road map for the first embodiment of the present invention, and Fig. 3 is a road map of the first embodiment of the present invention. 4 is a refrigerant circuit diagram of an air conditioner showing a second embodiment of the present invention, FIG. 5 is a refrigerant circuit diagram of an air conditioner/wafer unit showing a third embodiment of the present invention, and FIG. 7 is a refrigerant circuit diagram of an air conditioner showing a fourth embodiment of the present invention, FIG. 7 is a refrigerant circuit diagram of an air conditioner showing a fifth embodiment of the present invention, and FIG. 8 is a sixth embodiment of the present invention. A refrigerant circuit diagram of an air conditioner showing
FIG. 9 is a refrigerant circuit diagram of an air conditioner showing a seventh embodiment of the present invention, and FIG. 10 is a refrigerant circuit diagram of an air conditioner showing an eighth embodiment of the present invention.6(1)(1a) (lb)・”
Outdoor unit, (2) (2a) = variable capacity compressor,
(3a) (3b)...Outdoor heat exchanger, (5a>(
5b) (5c) ...indoor: r, = tsu1. ,
(6a) (6b) (6c) --- Indoor heat exchanger, (
7) (7a) (7b) - Refrigerant discharge pipe, (8) (8a)
(8b)... Refrigerant suction pipe, (9a) (10a),
(9b) (10b)...Outdoor side switching valve, (11)
... Uni-site piping, (12) ... High pressure gas pipe, (13) ... Low pressure gas pipe, (14) ... Liquid pipe, <15a) (16a), (15b) <16b )
, (15c) (16c) = indoor switching valve, (17
a) (17b) (17c) - Refrigerant pressure reducer, (26)
...Ability control means.

Claims (1)

[Claims] 1. In an air conditioner in which an outdoor unit with a variable capacity compressor and an outdoor heat exchanger is connected to multiple indoor units with built-in indoor heat exchangers through inter-unit piping, multiple outdoor heat exchangers are connected. Each unit is connected to a refrigerant discharge pipe and a refrigerant suction pipe of the compressor via an outdoor switching valve, while the inter-unit piping is connected to a high-pressure gas pipe connected to the discharge pipe and a refrigerant suction pipe. The indoor heat exchanger is composed of branch-connected low-pressure gas pipes and liquid pipes connected to a plurality of outdoor heat exchangers, and each indoor heat exchanger is connected to the high-pressure gas pipe and the low-pressure gas pipe with an indoor switching valve. The temperature or refrigerant pressure or air blowout of the indoor heat exchanger of the indoor unit in cooling operation and the indoor unit in heating operation is branched and connected to the liquid pipe through a refrigerant pressure reducer. An air conditioner comprising: capacity control means for varying the capacity of a variable capacity compressor and switching an outdoor switching valve according to temperature.