JP2567686B2 - Air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-room type air conditioner in which a plurality of indoor units are branched and connected to an indoor unit.

(B) Conventional technology Since refrigerant gas leaking from the refrigerant pipe of an air conditioner may endanger human life, refrigerant leakage is detected, compressor operation is stopped, and refrigerant gas is automatically released. A device for shutting off with a valve is disclosed in Japanese Utility Model Publication No. 60-38858.

(C) Problems to be Solved by the Invention When the political device is applied to a multi-room air conditioner in the above publication, if refrigerant gas leaks from one of a plurality of indoor units, the remaining normal indoor units However, there was a problem that all heating and cooling operations were stopped.

An object of the present invention is to provide an air conditioner that solves such problems.

(D) Means for Solving the Problem The present invention relates to an air conditioner in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units having an indoor heat exchanger are connected by unit pipes. While the outdoor heat exchanger is branched and connected to the refrigerant discharge pipe and the refrigerant suction pipe of the compressor through the outdoor switching valve, the inter-unit pipe is connected to the suction pipe and the low-pressure gas pipe is branched, and the discharge pipe. And a liquid pipe connected to an outdoor heat exchanger, and each indoor heat exchanger is connected to the high pressure gas pipe and the low pressure gas pipe via an indoor side switching valve. It is branched and connected to the liquid pipe via a refrigerant pressure reducing valve to detect refrigerant leakage from the refrigerant pipe of each indoor unit and close the indoor side switching valve and the refrigerant pressure reducing valve of the indoor unit where the refrigerant leaks. The control means is also provided.

(E) Action When cooling all rooms at the same time, by setting the outdoor switching valve and each indoor switching valve to the cooling state, the refrigerant discharged from the compressor flows from the discharge pipe to the outdoor heat exchanger. After being condensed and liquefied here, it is distributed to the refrigerant pressure reducing valve of each indoor unit through the liquid pipe, and after that, it is evaporated and vaporized in each indoor heat exchanger, and then compressed through the low pressure gas pipe and the refrigerant suction pipe in sequence. Inhaled into the machine. In this way, all the rooms are cooled by the indoor heat exchangers that act as evaporators.

Further, when heating all the rooms at the same time, by setting the outdoor switching valve and each indoor switching valve to the heating state, the refrigerant discharged from the compressor passes through the discharge pipe and the high-pressure gas pipe in sequence, and After being distributed to the indoor heat exchanger and condensed and liquefied there, they are merged with the liquid pipes through the refrigerant pressure reducing valves, and then evaporated and vaporized in the outdoor heat exchanger and then sucked into the compressor via the refrigerant suction pipe. To be done. In this way, all the rooms are heated by the indoor heat exchangers that act as condensers.

Further, in the case of simultaneously cooling any two chambers and heating one, for example, set the outdoor switching valve to the heating state and set the indoor switching valve of the indoor unit to be cooled to the cooling state,
In addition, when the indoor side switching valve of the indoor unit to be heated is set to the heating state, a part of the refrigerant discharged from the compressor flows to the outdoor heat exchanger and the remaining refrigerant is heated through the high-pressure gas pipe to the room of the indoor unit. It flows to the heat exchanger and is condensed and liquefied by the indoor heat exchanger and the outdoor heat exchanger. And the example condensed and liquefied in these heat exchangers is distributed to the refrigerant pressure reducing valve of each indoor unit through the liquid pipe, then evaporated and vaporized in each indoor heat exchanger, and then the low pressure gas pipe is changed to the refrigerant suction pipe. And is sequentially sucked into the compressor. In this way, one room is heated by the indoor heat exchanger that acts as a condenser, and two rooms are cooled by the other indoor heat exchanger that acts as an evaporator.

When the refrigerant gas leaks from the refrigerant pipe of any indoor unit during the cooling or heating operation and the simultaneous heating and cooling operation, the leakage is detected and the indoor side switching valve and the refrigerant pressure reducing valve of the indoor unit that leaks are blocked by the control means. Therefore, only the refrigerant gas in the refrigerant pipe of this indoor unit is released into the room, and a large amount of refrigerant gas existing in other indoor units and outdoor units etc. is not released, which may endanger human life. There is no.

Moreover, in other normal indoor units, the cooling and heating operation is continued by continuing the operation of the compressor, and the harmful effect is minimized.

(F) Example An example of the present invention will be described with reference to the drawings.
Is an outdoor unit having a compressor (2), an outdoor heat exchanger (3) and a gas-liquid separator (4), and (5a) (5b) (5c) are indoor heat exchangers (6a) (6b) (6c). ), The outdoor heat exchanger (3) is connected to the refrigerant discharge pipe (7) and the refrigerant suction pipe (8) of the compressor (2) by the outdoor switching valves (9a) (9).
High pressure, in which the inter-unit pipe (10) connecting the outdoor unit (1) and the indoor units (5a) (5b) (5c) is branched and connected to the refrigerant discharge pipe (7) while being branched and connected via b). Each room is composed of a gas pipe (11), a low-pressure gas pipe (12) branched and connected to the refrigerant suction pipe (8), and a liquid pipe (13) connected to the outdoor heat exchanger (3). Heat exchanger (6a) (6b)
The (6c) is connected to the high pressure gas pipe (11) and the low pressure gas pipe (12) by the indoor side switching valves (14a) (15a), (14b) (15b), (14).
c) Branch connection via (15c) and liquid pipe (13) via refrigerant pressure reducing valves (16a) (16b) (16c) such as an electric expansion valve. (17) is an auxiliary refrigerant pressure reducing valve such as an electric expansion valve interposed in the liquid pipe (13).

(18a) (18b) (18c) are each indoor unit (5a) (5
b) A refrigerant leak detector for detecting halogen elements constituting the refrigerant gas or detecting oxygen deficiency when the refrigerant gas leaks from the refrigerant pipe of each indoor unit to each indoor space by the control means provided in (5c). (19a) (19b) (19c) and alarm (2
0a), (20b) and (20c) are provided, and signals from the refrigerant leak detectors (19a) (19b) (19c) are supplied to respective control means (1).
8a) (18b) (18c) individually input and open / close valves (14a) (1
5a), (14b) (1ba), (14c) (15c) and the refrigerant pressure reducing valves (16a) (16b) (16c) are closed at the same time as the alarm (2
0a), (20b) and (20c) are activated to notify the refrigerant leak.

Next, the driving operation will be described. When cooling all the rooms at the same time, one outdoor switching valve (9a) is opened, the other outdoor switching valve (9b) is closed, and one indoor switching valve (14
By closing a) (15b) (14c) and opening the other indoor side switching valve (15a) (15b) (15c), the refrigerant discharged from the compressor (2) is discharged to the discharge pipe (7) and the outdoor side. After sequentially flowing through the switching valve (9a) and the outdoor heat exchanger (3) to condense and liquefy here, each indoor unit (5a) passes through the liquid pipe (13).
(5b) (5c) The refrigerant pressure reducing valves (16a) (16b) (16c) are distributed and the pressure is reduced there. After that, after evaporating and vaporizing in each indoor heat exchanger (6a) (6b) (6c), the indoor side switching valves (15a) (15b) (15c), low pressure gas pipe (12), suction pipe (8), respectively. ), And is sequentially sucked into the compressor (2) through the gas-liquid separator (4). In this way, all the rooms are simultaneously cooled by the indoor heat exchangers (6a) (6b) (6c) acting as evaporators.

On the contrary, when heating all the rooms at the same time, one outdoor side switching valve (9a) is closed, the other outdoor side switching valve (9b) is opened, and one indoor side switching valve (14a) (14b) (14c). ) And the other indoor side switching valve (15a) (15b) (15c)
By closing the, the refrigerant discharged from the compressor (2) passes through the discharge pipe (7) and the high-pressure gas pipe (11) in order, and the indoor side switching valves (14a) (14b) (14c) and the indoor heat exchanger ( 6a) (6
b) It is distributed to (6c), where after condensing and liquefying,
The refrigerant decompression valves (16a) (16b) (16c) are decompressed and merged in the liquid pipe (13), after which they are evaporated and vaporized by the outdoor heat exchanger (3), and then the outdoor switching valve (9b). , The suction pipe (8), and the gas-liquid separator (4) in this order, and then is sucked into the compressor (2). Each indoor heat exchanger (6a) thus acting as a condenser
In (6b) and (6c), all rooms are heated at the same time.

When, for example, cooling two arbitrary chambers and heating one chamber at the same time, one of the outdoor switching valves (9a) is opened and the other outdoor switching valve (9b) is closed, and the indoor chamber is cooled. One indoor switch valve (14a) (1) of unit (5a) (5c)
4c) is closed and the other indoor switching valve (15a) (15c)
To open and heat one indoor side switching valve (14b) of the indoor unit (5b) and the other indoor side switching valve (15).
When b) is closed, a part of the refrigerant discharged from the compressor (2) flows through the discharge pipe (7) and the outdoor switching valve (9a) to the outdoor heat exchanger (3), and the remaining refrigerant remains. It flows to the indoor side switching valve (14b) of the indoor unit (5b) for heating via the high pressure gas pipe (11) and the indoor heat exchanger (6b), and the indoor heat exchanger (6b) and the outdoor heat exchanger (3 ) And are condensed and liquefied. Then, the refrigerant condensed and liquefied in these heat exchangers (6b) (3) passes through the liquid pipe (13) and becomes the indoor units (5a) (5c).
After being decompressed by the refrigerant pressure reducing valves (16a) (16c) of the above, it is evaporated and vaporized by the respective indoor heat exchangers (6a) (6c), and then through the indoor side switching valves (15a) (15c). The low pressure gas pipe (12) joins, and the suction pipe (8) and the gas-liquid separator (4) are sequentially passed to the compressor (2). In this way, one room is heated by the indoor heat exchanger (6b) that acts as a condenser, and two rooms are cooled by the other indoor heat exchangers (6a) (6c) that act as an evaporator.

In this way, each indoor unit (5a) (5b) (5c) has its own indoor switching valve (14a) (15a), (14b) (15b), (14).
c) By opening and closing (15c), it is possible to perform heating / cooling operation arbitrarily.

In addition, when cooling one chamber and heating two chambers, it is possible to operate the auxiliary refrigerant pressure reducing valve (17).

For example, when the indoor unit (5b) is used for cooling and the indoor units (5a), (5c) are used for heating, one of the outdoor side switching valves (9
Close a) and open the other outdoor switching valve (9b),
Also, one indoor side switching valve (14b) of the indoor unit (5b) to be cooled and the other indoor side switching valve (15b) are opened, and one indoor side switching of the indoor units (5a) (5c) for heating is performed. When the valves (14a) (14c) are opened and the other indoor side switching valves (15a) (15c) are closed, the refrigerant discharged from the compressor (2) is discharged through the discharge pipe (7) and the high pressure gas pipe (11) in sequence. After that, it is distributed to the indoor side switching valves (14a) (14c) and condensed and liquefied in the respective indoor heat exchangers (6a) (6c). Then, the liquefied refrigerant is fully opened and the refrigerant pressure reducing valves (16a) (16c) are opened.
Flow through the liquid pipe (13), and a part of the liquid refrigerant in the liquid pipe is decompressed by the refrigerant pressure reducing valve (16b), and then the indoor heat exchanger (6
In b), the remaining liquid refrigerant is decompressed by the auxiliary refrigerant pressure reducing valve (17) and then evaporated and vaporized in the outdoor heat exchanger (3), respectively.
It is sucked into the compressor (2) through the suction pipe (8) and the gas-liquid separator (4) in this order. In this way, the indoor heat exchangers (6a) (6c) acting as condensers heat the two chambers, and the other indoor heat exchangers (6b) acting as evaporators cool the one chamber.

As described above, when the number of rooms to be cooled (cooling capacity) is larger than the number of rooms to be heated (heating capacity), the outdoor heat exchanger (3)
When the number of chambers to be heated (heating capacity) is smaller than the number of chambers to be cooled (cooling capacity), the outdoor heat exchanger (3) acts as an evaporator to turn any chamber into a condenser. It is possible to freely heat and cool, and at the same time, the indoor heat exchangers acting as the evaporator and the condenser perform heat recovery during the simultaneous heating and cooling operation, thereby improving the operation efficiency.

In this way, cooling or heating all of the multiple rooms at the same time,
At the same time, the room heat exchanger (6a) in the indoor unit (5a) is being operated, for example, while cooling any room and heating the other room.
The refrigerant leak detector (19a) detects the refrigerant gas leaking from the refrigerant pipe connection point of the above and is discharged into the indoor space where this indoor unit (5a) is installed, and the control means (18a)
A control signal is output from the indoor switching valve (14a) (15a)
The refrigerant pressure reducing valve (16a) and the alarm (2
0a) is activated to notify the refrigerant leakage.

Therefore, only the refrigerant gas in the refrigerant pipe of the indoor unit (5a) is released to the indoor space, and the refrigerant gas existing in the other indoor units (5b) and (5c), the outdoor unit (1), the inter-unit pipe (10), etc. Since a large amount of the refrigerant gas is not released into a small room, there is no risk of human life.

Moreover, the other normal indoor units (5b) and (5c) continue the cooling and heating operation by continuously operating the compressor (2), and other normal indoor units (5b) due to refrigerant gas leakage of the indoor unit (5a). Also in (5c), there is no harmful effect of stopping the operation.

In the above embodiment, three indoor units (5a) (5b)
(5c) was used, but even in the case of four or more indoor units with different capacities, it is sufficient to simply branch and connect to the inter-unit piping (10), and the compressor (2) is a frequency conversion type and has a number of poles With a variable capacity compressor such as a conversion type or unloader type, it is possible to suspend the operation of any indoor unit.

(G) Effect 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, which are a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe. With a simple circuit configuration using the outdoor heat exchanger, it is possible to freely select simultaneous cooling and heating operation for multiple indoor units as well as simultaneous heating and cooling operation 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 the simultaneous heating / cooling operation, efficient operation can be performed by heat recovery.

Moreover, during such simultaneous cooling operation, simultaneous heating operation and simultaneous heating and cooling operation, if refrigerant gas leaks from the refrigerant pipe of any indoor unit, the leak is detected and the indoor side switching valve and refrigerant pressure reducing valve of the leaked indoor unit are detected. Since the control means is blocked by the control means, only the refrigerant gas in the refrigerant pipe of this indoor unit is released indoors, and a large amount of the refrigerant gas existing in other indoor units and outdoor units is not released. Therefore, it is possible to prevent a risk of human life.

At the same time, there is no harmful effect of stopping the normal operation of the indoor unit due to the refrigerant gas leakage of the indoor unit, and the cooling or heating operation can be continued as it is.

In addition, the indoor switching valve that switches between simultaneous cooling operation, simultaneous heating operation, and simultaneous cooling and heating operation and the pressure reducing valve for refrigerant decompression are also used as a shutoff valve that blocks the discharge of the refrigerant gas. There is no need to add.

[Brief description of drawings]

Drawing is a refrigerant circuit diagram of an air harmony device showing an example of the present invention. (1) ... outdoor unit, (2) ... compressor, (3) ...
… Outdoor heat exchanger, (5a) (5b) (5c) …… Indoor unit, (6a) (6b) (6c) …… Indoor heat exchanger, (7) ……
Refrigerant discharge pipe, (8) …… Refrigerant suction pipe, (9a) (9b) ……
Outdoor switching valve, (10) …… Unit piping, (11) ……
High pressure gas pipe, (12) …… Low pressure gas pipe, (13) …… Liquid pipe,
(14a) (14b) (14c), (15a) (15b) (15c) ... indoor switching valve, (16a) (16b) (16c) ... refrigerant pressure reducing valve,
(18a) (18b) (18c) ... Control means.

Claims (1)

(57) [Claims] 1. An air conditioner in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, the outdoor heat exchanger being the compressor. While branch-connecting to the refrigerant discharge pipe and the refrigerant suction pipe via an outdoor switching valve, a low-pressure gas pipe branch-connected to the suction pipe and an inter-unit pipe, and a high-pressure gas pipe branch-connected to the discharge pipe And a liquid pipe connected to an outdoor heat exchanger, each indoor heat exchanger is branched and connected to the high-pressure gas pipe and the low-pressure gas pipe through an indoor-side switching valve, and to the liquid pipe. Is connected via a refrigerant pressure reducing valve, and is provided with control means for detecting a refrigerant leak from a refrigerant pipe of each indoor unit and closing the indoor side switching valve and the refrigerant pressure reducing valve of the indoor unit where the refrigerant has leaked. Air conditioner.