JPH0350466A - Air conditioner - Google Patents

Abstract

PURPOSE:To stabilize simultaneous operation of cooling and heating by connecting a refrigerant-adjusting container with a discharge tube through an on-off valve or providing a heater on the refrigerant adjusting container or providing a refrigerant pressure adjusting valve on a fluid tube between the refrigerant adjusting container on a unit to unit piping. CONSTITUTION:A title air conditioner comprises a high pressure gas pipe (11) in which a unit to unit piping (10) for connecting an outdoor unit (1) and room units (5a), (5b), (5c) is branched and connected to a refrigerant discharge tube (7), a low pressure gas tube (12) connected with a refrigerant suction tube (8) in branching, and a fluid tube (16) connected with the other ends of outdoor heat exchangers (3a), (3b) via auxiliary refrigerant pressure reducers (14a), (14b) of an electric motor driven expansion valve and the like and via a refriger ant adjusting container 15. The respective room units (5a), (5b), (5c) can arbitrar ily operates in cooling and heating by opening and closing respective changeover valves (17a)(18a), (17b)(18b), (17c)(18c) and respective changeover valves (9a)(10a), (9b)(10b) of the outdoor heat exchangers (3a)(3b).

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. This 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 Japanese Utility Model Publication No. 54-3020.

(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 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.

SUMMARY OF THE INVENTION 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 stable heating and cooling capacity during simultaneous heating and cooling operation.

(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. 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 end of the outdoor heat exchanger via a refrigerant adjustment container. 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. A heating and cooling system connected to a refrigerant regulator via a refrigerant pressure reducer, the refrigerant adjustment container is connected to the discharge pipe via an on-off valve, a heater is provided in the refrigerant adjustment container, or the refrigerant adjustment container and the inter-unit piping are connected to each other. A refrigerant pressure regulating valve is provided in the liquid pipe between the two.

(*〉Operation When cooling all rooms at the same time, set the switching valve of the outdoor heat exchanger and the switching valve of each indoor heat exchanger to the cooling state, so that the refrigerant discharged from the compressor is routed through the discharge pipe. After flowing into the outdoor heat exchanger and condensing and liquefied there, it is distributed to the refrigerant pressure reducer of each indoor unit via the refrigerant adjustment container and liquid pipe, and then evaporated and vaporized in each indoor heat exchanger, and then becomes a low-pressure gas. The refrigerant passes through the refrigerant pipe and the refrigerant suction pipe in sequence and is sucked into the compressor. In this way, all the rooms are cooled by each indoor heat exchanger that acts as an evaporator. Also, when heating all rooms at the same time, the outdoor heat is By setting the switching valve of the exchanger and the switching valve of each indoor heat exchanger to the heating state, nL of 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 being condensed and liquefied here, the refrigerants pass through each refrigerant pressure reducer and are combined in a liquid pipe.Then, they pass through a refrigerant adjustment container, are evaporated in an outdoor heat exchanger, and are then sucked into a compressor through a refrigerant suction pipe. In this way, all the rooms are heated with each indoor heat exchanger acting as a condenser.

During such cooling and heating operations, the refrigerant circulation amount is adjusted by the refrigerant adjustment container according to the number of indoor units being operated, so that stable heating and cooling capacity can be obtained even if the heating and cooling load changes.

Also, when simultaneously cooling one room and heating two rooms, set the switching valve of the outdoor heat exchanger to the cooling 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, the refrigerant discharged from the compressor flows through the high-pressure gas pipe to the indoor heat exchanger of each indoor unit to be heated. It is condensed and liquefied in a heat exchanger. The refrigerant condensed and liquefied in these heat exchangers is depressurized in each refrigerant pressure reducer, and then passes through liquid pipes to the indoor heat exchanger of the indoor unit that cools the air, and the remaining liquid refrigerant passes through the refrigerant adjustment container to the outside. It is evaporated in a heat exchanger, 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 one-room cooling and two-room heating operations, in winter when the outside air temperature is low, refrigerant tends to accumulate in the refrigerant adjustment container, and this accumulation of refrigerant causes refrigerant to flow into the indoor heat exchanger of the indoor unit that is being operated for cooling. When the cooling capacity decreases due to insufficient flow, the on-off valve is opened to guide the high-pressure gas refrigerant discharged from the compressor into the refrigerant adjustment container.
By heating the refrigerant in the refrigerant adjustment container with a heater or by reducing the valve opening of the refrigerant pressure adjustment valve and performing bomb-down operation, the refrigerant that has accumulated in the refrigerant adjustment container is expelled, resulting in a decrease in cooling capacity. is prevented. (f) Example The first example of the present invention will be explained based on FIG.
1) is a variable capacity compressor (2) and an outdoor heat exchanger (3a).
) (3b) and an outdoor unit having a gas-liquid separator <4>, (5a) (5b) (5c) is an indoor heat exchanger (6a)
<6b) In an indoor unit having (6C), one end of the outdoor heat exchanger (3a) (3b) is connected to the refrigerant discharge pipe (7) and refrigerant suction pipe (8) of the compressor (2) with a switching valve (9a). )(10
a), (9b) and (10b), while the outdoor unit (1) and indoor unit (5a) (5
b) High pressure gas pipe <12> where the inter-unit pipe (11> connecting with (5c) is branched and connected to the refrigerant discharge pipe (7))
and a low-pressure gas pipe (1) branch-connected to the refrigerant suction pipe (8).
3>, and a liquid pipe connected to the other end of the outdoor heat exchanger (3a) (3b) via an auxiliary refrigerant pressure reducer (14a) (14b) such as an electric expansion valve and a refrigerant adjustment container (15). 16), each indoor heat exchanger (6a) (6b) (6c)
One end is connected to the high pressure gas pipe 12) and the low pressure gas pipe (13) with switching valves (17a) (18a), (17b) (1), respectively.
8b), (17c) and (18c) and connected to the liquid pipe (16) via refrigerant pressure reducers (19a), (19b), and (19c) such as electric expansion valves.

(20a), (20b), and (20c) are sensors (2la), (22a), and . (2lb
) (22b) . (21c) (22c) is the indoor controller that detects the pressure and adjusts the valve opening of the refrigerant pressure reducer (19a) (19b) (19c), (23> is the indoor heat exchanger (6a) (6b) during cooling operation. ) (6c) with sensors (21a) (22a) . (2lb) (22b) ,
(21c) (22c), and the degree of superheat of the refrigerant exceeds the set value, and the refrigerant pressure reducer (19a) (19b
) (19c) is fully opened, the indoor controller (2Qa)
An outdoor controller that receives signals from (20b) and (20c) and opens the on-off valve (24) provided across the upper part of the refrigerant adjustment container (15) and the discharge pipe (7). <25> is a heat insulating material that prevents as much as possible the refrigerant from accumulating in the refrigerant adjustment container (15) when it is cooled when the outside temperature drops.

Next, the driving operation will be explained. When cooling all rooms at the same time, open one switching valve (9a) (9b) of each of the outdoor heat exchangers (3a) (3b), and open the other switching valve (10a).
) (10b) and indoor heat exchangers (6a) (6b).
) (6c) <17a) (17b) (1
7c) and close the externally operated switching valve (18a) (18
b) By opening (18c), the refrigerant discharged from the compressor (2) is transferred to the discharge pipe (7) and the switching valves (9a) (9b).
), the outdoor heat exchanger (3a) (3b) and after being condensed and liquefied there, the auxiliary refrigerant pressure reducer (14a) is fully opened.
(14b), the refrigerant adjustment container (15), and the liquid pipe (16) are distributed to the refrigerant pressure reducers (19a) (19b) (19c) of each indoor unit (5a) (5b) (5c), where the pressure is reduced. be done. After that, each indoor heat exchanger (6a) (6b
) After evaporation in (6c), the respective switching valves (18a)
(18b) (18c), the low-pressure gas pipe (13), the suction pipe (8>, and the gas-liquid separator (4>) and are sucked into the compressor (2>). In this way, each room that acts as an evaporator All the rooms are cooled at the same time by the heat exchangers (6a), (6b), and (6c).During this cooling operation, almost no liquid refrigerant (26) accumulates in the refrigerant adjustment container (15), and all rooms are cooled. A commensurate amount of refrigerant is circulated, but for example, if the indoor unit (5
b) When the cooling operation stops and the cooling load decreases due to turning off the operation switch or turning off the sensor, the switching valve (9b> (10b) of one of the outdoor heat exchangers (3b), for example, closes and the outdoor heat exchanger (3b) stops functioning as a condenser and is operated at a condenser capacity commensurate with the cooling load, and surplus refrigerant is stored in the refrigerant adjustment container (15), and an amount of refrigerant commensurate with the two-room cooling operation is circulated. Conversely, if you want to heat all rooms at the same time, use an outdoor heat exchanger (3a
) Close one switching valve (9a) (9b) of (3b) and open the other switching valve (10a) (10b), and switch one of the indoor heat exchangers (6a) (6b) (6c). By opening the valves (17a) (17b) (17C) and closing the other switching valves (18a) (18b) (18c), the refrigerant discharged from the compressor (2>) is transferred to the discharge pipe (7).
), the high pressure gas pipe <12> and then the switching valve (17a) (
17b) (17c), indoor heat exchanger (6a) (6b
) (6c), where after condensation and liquefaction,
The refrigerant is depressurized by each refrigerant pressure reducer (19a) (19b) (19c) and combined in the liquid pipe (16), then evaporated in the outdoor heat exchanger (3a) (3b), and then transferred to the switching valve (TOA). )
(fob), the suction pipe (8>, and the gas-liquid separator (4)) before being sucked into the compressor (2).In this way, each indoor heat exchanger (6a) (6b) (which acts as a condenser) 6c) all rooms are heated at the same time.

During such heating operation, almost no liquid refrigerant (26) accumulates in the refrigerant adjustment container (15), and a large amount of refrigerant suitable for heating operation in all rooms is circulated.
In case b), when the heating operation is stopped and the heating load becomes small due to the failure or failure of the operation switch, the switching valves (9b) and (10b) of one of the outdoor heat exchangers (3b), for example, are closed and this outdoor heat is removed. The exchanger (3b) stops functioning as an evaporator and is operated at a condenser capacity commensurate with the heating load, and excess refrigerant is stored in the refrigerant adjustment container <15>, and an amount of refrigerant commensurate with the two-room cooling operation is generated. is circulated.

Also, at the same time, any indoor unit (5a) (5c
) to heat two rooms and use the indoor unit (5b> to cool one room), use one switching valve (1) of the outdoor heat exchanger (3a>
0a) and open the other switching valve (9a) (9b) (1
0b), and closes one switching valve (17b) of the indoor unit (5b) for cooling, and closes the other switching valve (17b).
8b) and an indoor unit (5a) (
When one switching valve (17a) (17c) in 5c) is opened and the other switching valve (18a) (18c) is closed, the refrigerant discharged from the compressor (2>) flows into the discharge pipe (7).
, high pressure gas pipe (12>) and then the switching valve (17a) (1
7c) into respective indoor heat exchangers (6a) (6c).
) is condensed and liquefied. The liquefied refrigerant then flows into the liquid pipe (16) through the fully opened refrigerant pressure reducers (19a) and (19c), and a part of the liquid refrigerant in this liquid pipe is depressurized by the refrigerant pressure reducer (19b). After that, the remaining liquid refrigerant is depressurized in the indoor heat exchanger (6b), and the remaining liquid refrigerant is depressurized in the auxiliary refrigerant pressure reducer (14a>), and then evaporated in the outdoor heat exchanger (3a), respectively.
The compressor (2) passes through the suction pipe (8>, the gas-liquid separator (4))
〉 is inhaled. In this way, two rooms are heated by the indoor heat exchangers (6a) and (6c) which act as condensers, and one room is cooled by the other indoor heat exchanger (6b) which acts as an evaporator. In addition, during such simultaneous heating and cooling operation, the refrigerant pressure reducer (19a) (
19c) and fully open the auxiliary refrigerant pressure reducer (14a). In addition, during such simultaneous heating and cooling operation, in winter when the outside air temperature is low, refrigerant tends to accumulate in the refrigerant adjustment container (15), and this accumulation of refrigerant causes the indoor heat exchanger of the indoor unit (5b) that is being operated to cool. (6b) When the refrigerant no longer flows sufficiently and the refrigerant superheat degree of this indoor heat exchanger (6b) exceeds the set value, and the refrigerant pressure reducer (19b) is fully opened, the indoor controller (20b) Upon receiving the signal, the on-off valve (24) is opened by the signal from the outdoor controller (23), and the high-pressure gas refrigerant discharged from the compressor (2) flows into the refrigerant adjustment container (1).
5>, the liquid refrigerant accumulated in this refrigerant adjustment container (17) is heated, the internal pressure of this container increases, and the accumulated liquid refrigerant flows into the refrigerant circulation path. Since the refrigerant is expelled from the air, a sufficient amount of liquid refrigerant also flows into the indoor heat exchanger (6b), thereby preventing a decrease in cooling capacity. Moreover, if such simultaneous heating and cooling operation is performed in winter when the outside air temperature is low, the outdoor heat exchanger <3a> alone cannot draw sufficient heat from the outside air, resulting in a decrease in heating capacity. In such an operating state, the switching valve (tab) opens and the auxiliary refrigerant pressure reducer (14b) operates, and the other outdoor heat exchanger (3b) also acts as an evaporator, thereby preventing a decrease in heating capacity. .In this winter operation, for example, if the indoor unit (5c) turns off the thermostat and the heating operation stops and the heating load becomes small, the amount of heat source drawn from the outside air may be small. )(1
0b) is closed and only the other outdoor heat exchanger (3b) acts as an evaporator. In this way, each indoor unit (5a) (5b) (5c)
are the switching valves (17a), (18a), (17b), respectively.
(18b), (17c) (18C> and outdoor heat exchanger (3a) (3b>) switching valves (9a), (10a), (9
b) By opening and closing (10b), it is possible to perform heating and cooling operations as desired, and each indoor heat exchanger (6) acts as an evaporator and a condenser during simultaneous heating and cooling operation.
Heat recovery is performed in steps a), (6b), and (6c), and operational efficiency can be improved.

Fig. 2 shows a second embodiment of the present invention, which differs from the first embodiment in that instead of using an on-off valve (24), an electric heater (27) is wrapped around the refrigerant adjustment container (15). Similar to the first embodiment, for example, when the outdoor controller (23) receives a signal from the indoor controller (20b), the signal from the controller (23) turns on the electric heating. When the container (27) is energized, the refrigerant adjustment container (15)
The liquid refrigerant that has accumulated inside the container is heated and the internal pressure of this container increases, and the accumulated liquid refrigerant is expelled into the refrigerant circulation path, preventing a drop in cooling capacity. FIG. 3 shows a third embodiment of the present invention, which differs from the first embodiment in that instead of using an on-off valve (24), a refrigerant adjustment container (15) and an inter-unit pipe (1l) are used. Liquid pipe (
16a> is provided with a refrigerant pressure regulating valve (28>),
Similarly to the first embodiment, for example, the indoor controller (20b)
When the outdoor controller (23) receives a signal from the controller (23), the valve opening of the refrigerant pressure regulating valve (28) becomes smaller and pump-down operation is performed, which causes the refrigerant regulating vessel to open. (Since the liquid refrigerant accumulated in 15> is led out to the outdoor heat exchanger (3a) which acts as an evaporator, the amount of refrigerant circulation increases and a decrease in cooling capacity is prevented. In each of the above embodiments, three indoor units (5a, 5b, and 5c) were used, but even in the case of four or more indoor units with different capacities, they are simply branched and connected to the inter-unit piping (11). You can also use the switching valve (
9a〉(10a) , (9b)(10b) , (1
7a) (18a) , (17b) (18b) . (
Two-way valves were used for 17C) and 18c, but instead of these, the switching valves (9a) and (10a) were changed to three-way valves, and the switching valve (9a) was changed to a three-way valve.
b) A total of five three-way valves may be used, such as (10b) as a three-way valve. (G) Effects of the invention In the present invention, the inter-unit piping that connects the outdoor unit and the plurality of indoor units 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 units by simply branching them to the inter-unit piping, and you can freely select simultaneous cooling and heating operations for multiple indoor units as well as simultaneous cooling and heating operations for any indoor unit. In addition, 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 can be achieved through heat recovery. .

Furthermore, since a refrigerant adjustment container is installed in the liquid pipe between the outdoor heat exchanger and the inter-unit piping, the refrigerant circulation amount is adjusted according to the number of indoor units being operated, ensuring stable heating and cooling even when the heating and cooling load changes. capacity is obtained, and the refrigerant adjustment container is connected to the discharge pipe via an on-off valve, a heater is provided in the refrigerant adjustment container, or the refrigerant pressure is adjusted in the liquid pipe between the refrigerant adjustment container and the inter-unit piping. By providing the valve, it is possible to prevent the cooling capacity from decreasing due to excessive accumulation of refrigerant in the refrigerant adjustment container during one-room cooling and two-room heating operation.

[Brief explanation of drawings]

Fig. 1 is a refrigerant circuit diagram of a heating and cooling system showing a first embodiment of the present invention, Fig. 2 is a refrigerant circuit diagram of a heating and cooling system showing a second embodiment of the invention, and Fig. 3 is a refrigerant circuit diagram of a heating and cooling system showing a second embodiment of the invention. It is a refrigerant circuit diagram of a heating and cooling device showing an example. 《1)...Outdoor unit,
(2)...Compressor, (3a)<3b)...Outdoor heat exchanger, (5a)(5b)(5c)...Indoor unit, (6a)(6b>(6c)-Indoor heat exchanger,
(7) --- Refrigerant discharge pipe, (8) --- Refrigerant suction pipe,
(9a) (10a) , (9b)<10b)...
Switching valve, (11)... Inter-unit piping, (12)...
...High pressure gas pipe, (l3) ...Low pressure gas pipe, (1
5)...refrigerant adjustment container, (16')--liquid pipe,
(17a) (18a) , (17b) (18b) ,
(17c) (18c)...Switching valve, (19a)(
19b) (19c)...Refrigerant pressure reducer, (2>...
Opening/closing valve, (27)... Heater, (28)... Refrigerant pressure regulating valve.

Claims (1)

[Claims] 1. Outdoor heat exchange in an air-conditioning system in which an outdoor unit containing a compressor and an outdoor heat exchanger and a plurality of indoor units containing indoor heat exchangers are connected by inter-unit piping. One end of the unit is branch-connected to a refrigerant discharge pipe and a refrigerant suction pipe of the compressor via a switching valve, while the inter-unit piping is branch-connected to a high-pressure gas pipe branch-connected to the discharge pipe and a branch-connection to the suction pipe. A liquid pipe connected to the other end of the outdoor heat exchanger via a refrigerant adjustment container, and one end of each indoor heat exchanger is switched to the high pressure gas pipe and the low pressure gas pipe. The refrigerant adjustment container is connected to the discharge pipe via an on-off valve, and the other end of each indoor heat exchanger is connected to the liquid pipe via a refrigerant pressure reducer. heating and cooling equipment. 2. In a heating and cooling system in which an outdoor unit with a built-in compressor and an outdoor heat exchanger and multiple indoor units with built-in indoor heat exchangers are connected by inter-unit piping, one end of the outdoor heat exchanger is connected to the compressor. A high-pressure gas pipe is branch-connected to the refrigerant discharge pipe and the refrigerant suction pipe via a switching valve, while the inter-unit piping is branch-connected to the discharge pipe, and a low-pressure gas pipe is branch-connected to the suction pipe. It consists of a liquid pipe connected to the other end of the outdoor heat exchanger via a refrigerant adjustment container, 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. At the same time, the other end of each indoor heat exchanger is connected to the liquid pipe via a refrigerant pressure reducer, and the refrigerant adjustment container is provided with a heater. 3. In a heating and cooling system in which an outdoor unit with a built-in compressor and an outdoor heat exchanger and multiple indoor units with built-in indoor heat exchangers are connected by inter-unit piping, one end of the outdoor heat exchanger is connected to the compressor. A high-pressure gas pipe is branch-connected to the refrigerant discharge pipe and the refrigerant suction pipe via a switching valve, while the inter-unit piping is branch-connected to the discharge pipe, and a low-pressure gas pipe is branch-connected to the suction pipe. It consists of a liquid pipe connected to the other end of the outdoor heat exchanger via a refrigerant adjustment container, 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. At the same time, the other end of each indoor heat exchanger is connected to the liquid pipe via a refrigerant pressure reducer, and a refrigerant pressure adjustment valve is provided in the liquid pipe between the refrigerant adjustment container and the inter-unit piping. heating and cooling equipment.