JPH08226720A - Air conditioning equipment - Google Patents

Abstract

PURPOSE: To achieve a normal operation even when one room unit alone is connected to an outdoor unit of air conditioning equipment allowed to connect a plurality of room units. CONSTITUTION: A condensing means 7 for condensing a part of a surging refrigerant, a refrigerant tank 8 for storing the refrigerant condensed and a decompression means 9 are arranged successively between a discharging port 3a and a suction port 3b of a compressor 3 composing a refrigerating cycle of multiple air conditioning equipment to reduce the amount of a refrigerant flowing to a room unit 2A, thereby enabling normal operation of the room unit 2A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit.

[0002]

2. Description of the Related Art In a multi-type air conditioner in which a plurality of indoor units can be connected to one outdoor unit, a plurality of connected indoor units can be operated at the same time or one of them can be selectively operated. You can do it. FIG. 2 illustrates an example of a refrigeration cycle of a multi-type air conditioner. The refrigerant discharged from the compressor 22 provided on the outdoor unit 21 side passes through the four-way valve 23, and then is indicated by an arrow during heating operation. In the direction of the indoor unit 25 through the branch pipe 24.
The refrigerant that flows to A and 25B and returns returns through the expansion valves (refrigerant flow rate control valves) 26a and 26b provided in the outdoor unit 21, and then joins, and again from the outdoor heat exchanger 27 to the four-way valve 23.
And then returns to the compressor 22. Compressor 22
The refrigerant from the indoor units (indoor heat exchangers) 25A, 25B is in the form of high-temperature and high-pressure gas, but gradually changes to liquid in the process of flowing through the indoor heat exchanger, and most of the refrigerant in the refrigeration cycle has room heat. It will be present in the exchanger and the outdoor heat exchanger 27. Even if only one of the indoor units 25A and 25B is operated, a part of the refrigerant stays in the indoor heat exchanger of the stopped indoor unit, so that excess refrigerant may flow to the operating indoor unit. There is no such thing.

[0003]

However, even if the air conditioner as described above is used, the indoor unit 2 will be damaged for some reason.
If only one of 5A and 25B is connected, and the other is added later, and heating operation is performed,
The amount of refrigerant circulating in the indoor unit becomes excessive, and the pressure rises,
Since the temperature rises and falls into a so-called overload state, there is a problem that an overload protection device (not shown) operates and stable heating operation cannot be performed. Therefore,
An object of the present invention is to provide an air conditioner that does not cause such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, in which a refrigerant discharged from a compressor provided in an outdoor unit is circulated through a four-way valve, and then a plurality of branch pipes are provided. Of the indoor unit, and the refrigerant returned from each indoor unit to the outdoor unit is circulated through the corresponding expansion valve and then flowed into the outdoor heat exchanger, and returned to the compressor via the four-way valve again. In the air conditioner consisting of, between the discharge port and the suction port of the compressor, a condensing means for condensing a part of the discharged refrigerant, a refrigerant tank for accumulating the condensed refrigerant, and a pressure reducing means are connected in series. A bypass circuit provided with an electromagnetic opening / closing valve in parallel with the condensing means, and the electromagnetic opening / closing valve is closed when the number of indoor units connected to the outdoor unit does not reach a predetermined number. .

[0005]

With the above-mentioned structure, when only one indoor unit is connected to the outdoor unit capable of connecting a plurality of indoor units, the compressor is closed by closing the electromagnetic opening / closing valve of the bypass circuit. A part of the high-temperature, high-pressure gaseous refrigerant discharged from the condenser is condensed by the condensing means to become liquid and accumulated in the refrigerant tank. Therefore, an appropriate amount of refrigerant flows through the indoor unit, and normal heating operation can be performed. In addition, when two indoor units are connected to the outdoor unit, by opening the electromagnetic opening / closing valve of the bypass circuit, only the high temperature / high pressure gaseous refrigerant enters the refrigerant tank. A sufficient amount of refrigerant necessary for heating operation flows into the indoor unit, which enables normal operation.

[0006]

An embodiment of the present invention will be described below with reference to FIG. Fig. 1 shows the refrigeration cycle of a multi-type air conditioner in which only one indoor unit is connected.
Is an outdoor unit, 2A is an already connected indoor unit (indoor heat exchanger),
2B is an indoor unit that will be connected at a later date. Two indoor units 2A, 2
When B is connected, both 2A and 2B can be operated simultaneously or any one of them can be operated arbitrarily. The outdoor unit 1 has a compressor 3, a four-way valve 4 for switching the flow of refrigerant,
In addition to the expansion valves (refrigerant flow rate control valves) 5a and 5b corresponding to the indoor units 2A and 2B and the outdoor heat exchanger 6, it is possible to perform normal heating operation and the like even when there is only one indoor unit. Further, between the discharge port 3a and the suction port 3b of the compressor 3, a condensing means 7 for condensing a part of the discharged refrigerant, a refrigerant tank 8 for accumulating the refrigerant condensed by the condensing means 7 and a capillary tube are provided. The pressure reducing means 9 used is connected in series, and an electromagnetic opening / closing valve 10 is provided between the inlet side of the condensing means 7 and the refrigerant tank 8.
A bypass circuit 11 is provided.

The condensing means 7 is integrated with the outdoor heat exchanger 6 and the compressor 3 is closed by closing the electromagnetic opening / closing valve 10.
Although a part of the high-temperature and high-pressure gaseous refrigerant discharged from the unit can be condensed, in the present embodiment, only one of the indoor units 2A and 2B is connected to the outdoor unit 1 and the heating operation is performed. Only when it is performed, the electromagnetic on-off valve 10 is closed by a command from the outdoor unit control unit (not shown), and the refrigerant liquefied by the condensing means 7 is stored in the refrigerant tank 8 so that the indoor unit (2A ) To prevent excess refrigerant from flowing. In addition, the outdoor unit 1 has indoor units 2A and 2B.
Is connected, and when both are operated at the same time, there is no problem because an appropriate amount of refrigerant circulates in each, but when only one is operated for heating, there is a large amount of refrigerant that accumulates on the indoor unit side when the operation is stopped. Therefore, in the present embodiment, the electromagnetic on-off valve 10 is opened to prevent the refrigerant from staying in the refrigerant tank 8, and the expansion valve 5a or 5b corresponding to the indoor unit in the operation stop is set to a predetermined value. The valve is opened to the open angle to eliminate the lack of refrigerant in the indoor unit during operation.

[0008]

EFFECTS OF THE INVENTION With the multi-type air conditioner described above, normal operation can be performed even if a predetermined number of indoor units are not connected, and problems such as reduced heating capacity can be solved. It

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a multi-type air conditioner showing an embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram of a multi-type air conditioner showing a conventional example.

[Explanation of symbols]

 1 Outdoor unit 2A Indoor unit (indoor heat exchanger) 2B Indoor unit (indoor heat exchanger) 3 Compressor 4 Four-way valve 5a Expansion valve 5b Expansion valve 6 Outdoor heat exchanger 7 Condensing means 8 Refrigerant tank 9 Pressure reducing means (capillary tube) ) 10 solenoid on-off valve 11 bypass circuit

Claims (5)

[Claims] 1. A refrigerant discharged from a compressor provided in an outdoor unit is circulated through a four-way valve and then branched into a plurality of indoor units by a branch pipe to deal with the refrigerant returned from each indoor unit to the outdoor unit. In an air conditioner that is made to flow into an outdoor heat exchanger after being circulated through an expansion valve and returned to the compressor via the four-way valve again, between the discharge port and the suction port of the compressor, the discharge Condensing means for condensing a part of the refrigerant, a refrigerant tank for accumulating the condensed refrigerant, and a pressure reducing means are provided in series, and a bypass circuit provided with an electromagnetic opening / closing valve in parallel to the condensing means is provided, and An air conditioner characterized in that when the number of indoor units connected to the outdoor unit does not reach a predetermined number, the electromagnetic opening / closing valve is closed. 2. The air conditioner according to claim 1, wherein the condensing means is provided integrally with the outdoor heat exchanger. 3. The air conditioner according to claim 1, wherein the depressurizing means is a capillary tube. 4. The air conditioner according to claim 1, wherein the electromagnetic opening / closing valve is closed only during heating operation. 5. A plurality of indoor units are connected to the outdoor unit,
When only one of them is operated for heating, the solenoid on-off valve is opened and the expansion valve corresponding to the indoor unit that is not in operation is opened to a predetermined opening angle. The air conditioner according to claim 1.