JP2002022314A - Pefrigerant branch unit of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct recovery of ice machine oil and a refrigerant, a defrosting operation, etc., without passing through an indoor machine and to ensure comfortableness as a place where the indoor machine is installed. SOLUTION: A liquid pipe 333 connected to the liquid pipe in a refrigerant circuit at an outdoor machine side, a gas pipe 337 connected to the gas pipe side in the refrigerant circuit of the outdoor machine side, a plurality of liquid- pipe-side branch piping parts 334A-334C connected to the liquid pipe side in the refrigerant circuit at the indoor machine side, a plurality of gas-pipe-side branch piping parts 335A-335C connected to the gas pipe side in the refrigerant circuit at the indoor machine side, a liquid pipe branch part 331, a gas pipe branch part 336, a bypass line 308 bypassing the liquid pipe part 333 and the gas pipe part 337, and a motor operated valve 338 disposed on the bypass line 308, are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant branch unit of an air conditioner which is disposed between an outdoor unit and an indoor unit and distributes refrigerant to a plurality of indoor units, and air provided with such a refrigerant branch unit. Concerning the harmonic machine.

[0002]

2. Description of the Related Art In an air conditioner comprising an outdoor unit and an indoor unit, a pair-type air conditioner in which one indoor unit is connected to one outdoor unit, and a pair type air conditioner in which one outdoor unit is connected to one outdoor unit. There is a multi-type air conditioner to which a plurality of indoor units are connected.

[0003] In the pair-type air conditioner, the refrigerant pipe connection port corresponds to the outdoor unit and the indoor unit in a one-to-one correspondence, whereas in the multi-type air conditioner, the indoor unit that can be connected to the outdoor unit is connected. A number of refrigerant pipe connection ports are provided and can be connected to a plurality of indoor units.

[0004] Further, by using a refrigerant branching unit having an outdoor refrigerant pipe port and a plurality of indoor refrigerant pipe ports and capable of distributing refrigerant to a plurality of indoor units, a pair-type outdoor unit is provided. Thus, it is possible to connect a plurality of indoor units, and it is also possible to connect more than the number of indoor units to the multi-type outdoor unit.

[0005]

The outdoor refrigerant pipe port in the branch unit as described above comprises an outdoor liquid pipe connection port and an outdoor gas pipe connection port, and the indoor refrigerant pipe port is an indoor liquid pipe connection port. And an indoor gas pipe connection port. A liquid pipe-side pipe branching from the liquid pipe section to the liquid pipe-side branch pipe section via the liquid pipe branch section is provided between the outdoor-side liquid pipe connection port and the indoor-side liquid pipe connection port.
Similarly, between the outdoor side gas pipe connection port and the indoor side gas pipe connection port, a gas pipe side pipe branching from the gas pipe section to the gas pipe side branch pipe section via the gas pipe branch section is provided.

[0006] Since the refrigerant is distributed by the liquid pipe branch and the gas pipe branch in the branch unit, the refrigerant pipe diameter from the outdoor unit to the refrigerant branch unit has a refrigerant pipe diameter from the refrigerant branch unit to the indoor unit. Larger than the diameter.

Therefore, when some of the connected indoor units are not operating, particularly when the number of operating indoor units is small, the refrigerant pipe between the outdoor unit and the refrigerant branch unit must be connected. The flow rate of the refrigerant passing therethrough may be reduced, and the refrigerating machine oil circulating in the refrigerant may adhere to the pipe wall of the refrigerant pipe. When driving in such a state for a long time,
Insufficient amount of refrigerating machine oil collected in the compressor causes deterioration of the performance of the compressor and failures such as burn-in.

[0008] As a method of recovering the refrigerating machine oil, the decompression circuit of each connected indoor unit is controlled so that the refrigerant circulates even in the indoor heat exchanger that is not operating, and the refrigerating machine oil is regenerated by the liquid refrigerant. Can be recovered.

[0009] However, in each indoor unit, a refrigerant passing sound is generated by the refrigerant passing through the indoor heat exchanger, and there is a possibility that the comfort at the installation location of the indoor unit is impaired.

[0010] In addition, in the low outdoor air heating operation, if the temperature of the outdoor heat exchanger drops and frost adheres, the air conditioning capacity decreases, and thus defrosting (defrost) for melting ice attached to the outdoor heat exchanger. It is conceivable to drive. This defrosting operation is performed by controlling the pressure reduction circuit of each indoor unit so that the refrigerant circulates in each indoor heat exchanger.

[0011] Also in the case of this defrosting operation, the refrigerant passing through the indoor heat exchanger generates a refrigerant passing sound in each indoor unit, and there is a possibility that the comfort at the installation location of the indoor unit is impaired.

Further, when the low outside air heating is started, there is a possibility that the condensed liquid refrigerant may accumulate in the communication pipe on the gas pipe side. There is a case where the accumulation preventing operation for circulating the refrigerant in the exchanger is performed. Also in this case, there is a problem due to the refrigerant passing sound as described above.

In order to reduce the above-mentioned refrigerant passage noise, it is necessary to reduce the opening of the pressure reducing circuit, and the respective effects are reduced accordingly. Therefore, it is necessary to perform each control operation for a long time or to perform the control frequently, which results in further impairing comfort.

The present invention makes it possible to perform refrigerating machine oil recovery, refrigerant recovery, defrosting operation, and the like without using an indoor unit.
The purpose is to ensure comfort in the indoor unit installation location.

[0015]

A refrigerant branch unit of an air conditioner according to the present invention is a refrigerant branch unit of an air conditioner for connecting an outdoor unit refrigerant circuit and a plurality of indoor unit refrigerant circuits. There is a liquid pipe connected to the liquid pipe side of the outdoor unit refrigerant circuit, a gas pipe connected to the gas pipe side of the outdoor unit refrigerant circuit, and a liquid pipe connected to the indoor unit refrigerant circuit. A plurality of liquid pipe side branch pipe sections, a plurality of gas pipe side branch pipe sections connected to the gas pipe side of the indoor unit side refrigerant circuit, and a liquid pipe branching from the liquid pipe section to the liquid pipe side branch pipe section. A branch portion, a gas pipe branch portion that branches from the gas pipe portion to the gas pipe side branch pipe portion,
The apparatus includes a bypass pipe for bypassing the liquid pipe section and the gas pipe section, and a motor-operated valve disposed on the bypass pipe.

Here, it is possible to adopt a configuration in which a pressure reducing circuit is provided in each liquid pipe side branch pipe section. Further, each gas pipe side branch pipe section may be provided with a gas pipe temperature sensor for detecting the temperature of the refrigerant passing therethrough.

Further, each of the branch pipe sections on the liquid pipe side may be provided with a liquid pipe temperature sensor for detecting the temperature of the refrigerant passing therethrough. Further, the liquid pipe section and each liquid pipe side branch pipe section are connected to each other so that heat can be exchanged between the refrigerant passing through the liquid pipe section and the refrigerant passing through each liquid pipe side branch pipe section. It is also possible to configure a heavy pipe gas-liquid heat exchanger.

An air conditioner according to the present invention includes an outdoor unit, an indoor unit, and a refrigerant branch unit. The outdoor unit has an outdoor unit-side refrigerant circuit, and the indoor unit has an indoor unit-side refrigerant circuit. Further, the refrigerant branch unit includes a liquid pipe portion connected to the liquid pipe side of the outdoor unit-side refrigerant circuit, a gas pipe portion connected to the gas pipe side of the outdoor unit-side refrigerant circuit, and a liquid pipe portion connected to the indoor unit-side refrigerant circuit. A plurality of liquid pipe side branch pipe sections connected to the pipe side,
A plurality of gas pipe-side branch pipe sections connected to the gas pipe side of the indoor unit-side refrigerant circuit; a liquid pipe branch section that branches from the liquid pipe section to the liquid pipe-side branch pipe section; and a gas pipe section from the gas pipe side. It has a gas pipe branch part branched to a branch pipe part, a bypass pipe which bypasses the liquid pipe part and the gas pipe part, and a bypass motor operated valve arranged on the bypass pipe. Thus, the opening degree control of the bypass motor-operated valve is performed according to the current operating condition.

Here, when the refrigerating machine oil is collected between the outdoor unit side refrigerant circuit and the refrigerant branch unit, the bypass motor-operated valve can be configured to be opened for a predetermined period of time, so that the defrosting operation during the low outdoor air heating operation is performed. The opening degree control of the bypass electric valve can be performed, and further, the opening degree control of the bypass electric valve can be performed to prevent accumulation of condensed refrigerant in the gas pipe communication pipe at the time of low outside air heating startup. Can be configured.

[0020]

FIG. 1 shows an air conditioner to which an embodiment of the present invention is applied. FIG. 1 shows an example in which an outdoor unit for a paired device and a plurality of indoor units for a paired device are connected, but the indoor unit and the outdoor unit of the paired air conditioner and the multi-type air conditioner are arbitrarily combined. It can be used by connecting with.

The outdoor unit 100 includes a compressor 101, a four-way switching valve 102, an outdoor heat exchanger 103, an electric pressure reducing valve 104,
An accumulator 105 and the like are provided. Compressor 101
Is provided with a discharge side pressure protection switch 108 for detecting an abnormal rise in the discharge pressure.
Is provided with a suction-side pressure sensor 110 for detecting a suction pressure.

An oil separator 107 for separating lubricating oil contained in the refrigerant and returning it to the accumulator 105 is provided on the discharge side of the compressor 101. A discharge pipe thermistor 109 for detecting the temperature on the discharge side of the compressor 101 is attached to the oil separator 107.

A pressure adjusting valve 113 is provided in a path connecting the outlet side of the oil separator 107 and the inlet side of the accumulator 105. The outdoor unit 100 also includes an outdoor air thermistor 111 for detecting the outdoor air temperature, and an outdoor heat exchange thermistor 112 for detecting the temperature of the outdoor heat exchanger 103.

The refrigerant pipes led from the outdoor unit 100 to the indoor unit are connected to a liquid pipe connection port 114 led through the electric pressure reducing valve 104 and a gas pipe connection led via the four-way switching valve 102. And a liquid pipe closing valve 116 and a gas pipe closing valve 117 provided inside each connection port.

The indoor unit 200 for the paired machine is
The refrigerant pipe connected to the indoor heat exchanger 201 is led to the outdoor unit via a liquid pipe connection port 204 and a gas pipe connection port 205.

The indoor unit 200 has a room temperature thermistor 202 for detecting the indoor temperature and an indoor heat exchange thermistor 20 for detecting the temperature of the indoor heat exchanger 201.
3 is provided.

In FIG. 1, three indoor units 200 for a pair are connected to each other, and the same parts of each indoor unit 200 are denoted by the same reference numerals. The outdoor unit 100 for a paired device and the indoor units 200 for a paired device are connected via a branching unit 300.

The branch unit 300 has an outdoor liquid pipe connection port 301 connected to the liquid pipe connection port 114 of the outdoor unit 100 and an indoor liquid pipe connection port 302 connected to the liquid pipe connection port 204 of the indoor unit 200. An outdoor gas pipe connection port 303 connected to the gas pipe connection port 115 of the outdoor unit 100, and a gas pipe connection port 20 of the indoor unit 200.
5 connected to the indoor side gas pipe connection port 304. The indoor-side liquid pipe connection port 302 and the indoor-side gas pipe connection port 304 are prepared by the number of the indoor units 200 to be connected. Here, three each are provided. Further, a branch path is formed for branching from the outdoor-side liquid pipe connection port 301 to each indoor-side liquid pipe connection port 302, and similarly branches from the outdoor-side gas pipe connection port 303 to each indoor-side gas pipe connection port 304. A fork is formed.

A branch valve from the outdoor-side liquid pipe connection port 301 in the branch unit 300 to each indoor-side liquid pipe connection port 302 has a motor-operated valve 305 for reducing the pressure of the refrigerant passing therethrough, A liquid tube thermistor 306 for detecting the temperature of the refrigerant passing therethrough is provided.
A gas pipe thermistor 307 for detecting the temperature of the refrigerant passing through the inside of the branch path from the outdoor gas pipe connection port 303 to each indoor gas pipe connection port 304 in the branch unit 300 is provided. .

Further, a bypass pipe 308 for bypassing the outdoor liquid pipe connection port 301 and the outdoor gas pipe connection port 303 is provided.
Is provided with a bypass motorized valve 338 capable of adjusting the flow rate.

Here, a liquid pipe thermistor 306 for detecting the refrigerant temperature in the liquid pipe on the indoor unit side in the branch unit 300
Therefore, even when a plurality of indoor units for paired units 200 without liquid tube temperature sensors are connected to such a branch unit 300, it is possible to perform temperature control on each indoor unit 200. Become.

The decompression operation on the liquid pipe side is performed by setting the decompression motor-operated valve 104 provided in the outdoor unit 100 to a predetermined opening degree, and setting the motor-operated valve 30
5 can be controlled by adjusting the degree of opening, and the pressure reducing electric valve 104 and the electric valve 305 can be combined and controlled.

[Branch unit internal structure] Branch unit 3
FIGS. 5 and 6 show the structure of the branch portion incorporated in the 00. Inside the branch unit 300, refrigerant pipes are provided between the outdoor-side liquid pipe connection port 301, the outdoor-side gas pipe connection port 303, the indoor-side liquid pipe connection ports 302A to 302C, and the indoor-side gas pipe connection ports 304A to 304C. A branching portion for branching is configured.

The liquid pipe section 333 connected to the outdoor liquid pipe connection port 301 is introduced into the gas-liquid heat exchanger 330,
Branch pipes 332A, 332B via the liquid pipe branch part 331,
332C. Each branch pipe 332A-332
C has electric valves 305A to 305C, respectively, and is configured to be introduced into the gas-liquid heat exchanger 330 immediately after the electric valves 305A to 305C.

Connection pipe sections 334A to 334C derived from the gas-liquid heat exchanger 330 of each of the branch pipes 332A to 332C.
Are the indoor liquid pipe connection ports 302A to 302C, respectively.
It is connected to the.

Indoor gas pipe connection ports 304A-304
Connection pipes 335A to 335C are connected to C, respectively. Each of the connection pipes 335A to 335C is connected to a gas pipe 337 via a gas pipe branch 336.
The gas pipe 337 is connected to the outdoor gas pipe connection port 303. A bypass pipe 308 is provided between the liquid pipe section 333 and the gas pipe section 337, and a bypass electric valve 338 capable of adjusting a flow rate is provided in the bypass pipe 308.

Indoor-side liquid pipe connection ports 302A to 302C
And connection pipe sections 334A to 334C and 335A to 340A to 334C located near the indoor side gas pipe connection ports 304A to 304C.
335C is provided with liquid pipe thermistors 306A to 306C and gas pipe thermistors 307A to 307C for detecting the temperature of the refrigerant passing therethrough.

[Refrigerant Oil Recovery Control] Refrigerator oil recovery control during cooling operation will be described with reference to the flowchart of FIG.

In step S1, the counting of the collection interval timer is started. The refrigerating machine oil recovery process is configured to be automatically executed at predetermined time intervals when a state in which the number of operating indoor units is small continues. The continuation time during which the number of indoor units during operation is small is counted by the collection interval timer.

In step S2, it is determined whether the number of operating indoor units is small. Here, when the number of operating indoor units is smaller than the number of connected indoor units, it can be determined that the number of operating units is small. In addition, it is possible to appropriately set, for example, when it is considered that the number of operating units is small when only one indoor unit is in operation, or when the number of operating units is small when there are two or less indoor units. If it is determined in step S2 that the number of operating vehicles is small, the process proceeds to step S3.

In step S3, it is determined whether or not the count value of the collection interval timer has exceeded a predetermined time. The interval at which the refrigerating machine oil recovery processing is performed is set according to the performance of the connected outdoor unit 100 and indoor unit 200, the installation environment, and the like. If the count value of the collection interval timer has exceeded the predetermined time, the process proceeds to step S4.

In step S4, the bypass motor-operated valve 338
Is set, and the counting of the collection timer is started. The degree of opening of the bypass electric valve 338 is set according to the outdoor unit 100.
And the performance of the indoor unit 200, each refrigerant pipe diameter, collection interval,
It is set according to the number of indoor units currently operating. In addition, a collection timer for counting an elapsed time from the start of the refrigerating machine oil collection process is started.

In step S5, it is determined whether or not the count value of the collection timer has exceeded a predetermined value. A predetermined period of time, which is considered to be sufficient for collecting the refrigerating machine oil in the refrigerant circuit, is set in advance, and when the count value of the collection timer exceeds the predetermined period, the process proceeds to step S6.

In step S6, the bypass motor-operated valve 338
Is closed. In step S7, the collection interval timer and the count value of the collection timer are reset, and the collection interval timer is restarted.

With such a configuration, the refrigerating machine oil recovery process can be performed at predetermined time intervals. At this time, the liquid refrigerant flows through the bypass electric valve 338 in the branch unit 300, and the refrigerant does not flow into the indoor heat exchanger 201 of the indoor unit 200. Therefore,
Refrigerant passing noise is not generated at the installation location of the indoor unit 200, and the comfort is not impaired.

It is also possible to omit step S2 in the above-mentioned flowchart and execute the refrigerating machine oil recovery process at predetermined time intervals regardless of the number of operating units. [Defrosting operation control] When the conditions for starting the defrosting operation such as when frost adheres to the outdoor heat exchanger 103 during the low outdoor air heating operation are satisfied, the bypass electric valve 33 is activated.
The defrosting operation is performed by controlling the opening degree of No. 8.

Also in this case, the outdoor unit 100 and the indoor unit 2
00 bypass electric valve 33 according to the performance of
The defrosting operation is performed by performing the opening degree control of No. 8. This defrosting operation process can also be configured to be automatically executed at predetermined time intervals, and this process is executed when the defrosting operation is necessary based on the detection values of the sensors of each unit. May be configured.

[Liquid accumulation prevention control] At the start of the low outside air heating operation, in order to prevent accumulation of the condensed refrigerant in the gas communication pipe, the opening degree of the bypass electric valve 338 is controlled to perform the operation. Perform the operation to prevent accumulation.

Also in this case, the outdoor unit 100 and the indoor unit 2
The opening degree control of the bypass motor-operated valve 338 is performed based on the performance of the 00, the number of operating indoor units, and the external environment.

[0050]

According to the present invention, the opening degree of the bypass electric valve provided in the refrigerant branching unit is controlled in the indoor heat exchanger during the refrigerating machine oil recovery processing, the defrosting operation, the liquid accumulation prevention control, and the like. Since the processing can be performed without allowing the refrigerant to pass through, the refrigerant passing sound at the indoor unit installation location does not occur, and the comfort is not impaired.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an internal configuration of a refrigerant branch unit.

FIG. 3 is a perspective view of an internal configuration of a refrigerant branch unit.

FIG. 4 is a flowchart of refrigerating machine oil recovery control.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 outdoor unit 101 compressor 102 four-way switching valve 103 outdoor heat exchanger 105 accumulator 300 branch unit 308 bypass line 338 bypass electric valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Sakamoto 2F, Oya 1000 Oya, Okamotocho, Kusatsu-shi, Shiga F-term in Shiga Works (reference) 3L060 AA01 AA05 CC04 DD02 EE09 3L092 GA02 GA04 GA09 HA08 HA10 JA02 JA07 JA09 KA15 KA17 LA03

Claims (9)

[Claims] 1. A refrigerant branch unit (300) of an air conditioner for connecting an outdoor unit-side refrigerant circuit and a plurality of indoor unit-side refrigerant circuits, wherein the refrigerant branch unit (300) is provided on a liquid pipe side of the outdoor unit-side refrigerant circuit. Connected liquid tube (3
33), a gas pipe section (337) connected to the gas pipe side of the outdoor unit side refrigerant circuit, and a plurality of liquid pipe side branch pipe sections (334A) connected to the liquid pipe side of the indoor unit side refrigerant circuit. To 334C), a plurality of gas pipe side branch pipe sections (335A to 335C) connected to the gas pipe side of the indoor unit side refrigerant circuit, and the liquid pipe section (333) to the liquid pipe side branch pipe section ( 33
4A to 334C), and a gas pipe branch (33) branching from the gas pipe (337) to the gas pipe side branch pipe (335A to 335C).
6), a bypass pipe (308) for bypassing the liquid pipe section (333) and the gas pipe section (337), and an electric valve (3) disposed on the bypass pipe (308).
38), a refrigerant branch unit for an air conditioner comprising: 2. The liquid pipe side branch pipe section (334A-33).
4. The refrigerant branch unit for an air conditioner according to claim 1, further comprising a pressure reducing circuit (305A to 305C) in 4C). 3. The gas pipe-side branch pipe section (335A to 3A).
The refrigerant branch unit for an air conditioner according to claim 1 or 2, further comprising a gas pipe temperature sensor (307A to 307C) for detecting a temperature of a refrigerant passing through the inside at 35C). 4. The liquid pipe side branch pipe section (334A-33).
The refrigerant branch unit for an air conditioner according to any one of claims 1 to 3, further comprising a liquid pipe temperature sensor (306A to 306C) for detecting the temperature of the refrigerant passing through the inside of the air conditioner (4C). 5. The liquid so as to enable heat exchange between the refrigerant passing through the liquid pipe section (333) and the refrigerant passing through each liquid pipe side branch pipe section (334A to 334C). The pipe section (333) and the respective liquid pipe side branch pipe sections (334A to
The refrigerant branching unit for an air conditioner according to any one of claims 1 to 4, wherein the refrigerant pipe (334C) constitutes a double pipe gas-liquid heat exchanger (330). 6. An outdoor unit (10) having an outdoor unit-side refrigerant circuit.
0), a plurality of indoor units (200) including an indoor unit-side refrigerant circuit, and a liquid pipe unit (3) connected to the liquid pipe side of the outdoor unit-side refrigerant circuit.
33), a gas pipe section (337) connected to the gas pipe side of the outdoor unit side refrigerant circuit, and a plurality of liquid pipe side branch pipe sections (334A) connected to the liquid pipe side of the indoor unit side refrigerant circuit. ~ 3
34C) and a plurality of gas pipe side branch pipe sections (335A to 335C) connected to the gas pipe side of the indoor unit side refrigerant circuit.
And a liquid pipe branch section (33) that branches from the liquid pipe section (333) to the liquid pipe side branch pipe section (334A to 334C).
1), a gas pipe branch section (337) branching from the gas pipe section (337) to the gas pipe side branch pipe sections (335A to 335C), the liquid pipe section (333), and the gas pipe section (33).
7) a refrigerant branch unit (300) having a bypass pipe (308) for bypassing the above (7), and a bypass electric valve (338) disposed on the bypass pipe (308).
An air conditioner comprising: controlling the opening degree of the bypass motor-operated valve (338) according to the current operating condition. 7. The air according to claim 6, wherein when the refrigerating machine oil is recovered between the outdoor unit side refrigerant circuit and the refrigerant branch unit, the bypass electric valve (338) is opened for a predetermined time. Harmony machine. 8. The air conditioner according to claim 6, wherein, when performing a defrosting operation during the low outside air heating operation, the opening degree control of the bypass electric valve (338) is performed. 9. An opening control of the bypass motor-operated valve (338) is performed to prevent accumulation of condensed refrigerant in the gas pipe communication pipe at the time of starting the low outside air heating. The air conditioner according to item 1.