JP2006125716A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable suppressing vibration, noise, or the like even when changing, for example, from operation of mainly cooling to operation of mainly heating. <P>SOLUTION: A single passage selector valve 41 is provided for alternatively branching and connecting one end of an outdoor heat exchanger 21 to a refrigerant discharge pipe 7 and a refrigerant suction pipe 6 of a compressor 20. The passage selector valve 41 is composed such that a movable member is housed in a valve body, and a refrigerant passage can be changed by pressing movement of the movable member. A pilot valve is provided, and it is composed such that the movable member can be freely pressed by using a high pressure refrigerant in a high pressure gas pipe 7 by switching the pilot valve. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention has an outdoor unit and a plurality of indoor units, and allows the plurality of indoor units to perform cooling operation or heating operation at the same time, or to perform a mixture of these heating operation and cooling operation. Relates to the device.

In general, an air conditioner is known in which a plurality of indoor units can be simultaneously operated for cooling or heating, or these heating and cooling operations can be performed in combination (see Patent Document 1). In this type of air conditioner, an outdoor unit including a compressor and an outdoor heat exchanger and a plurality of indoor units including an indoor heat exchanger and an indoor expansion valve are connected to each other through an inter-unit pipe. And, one end of the outdoor heat exchanger is alternatively branched and connected to the refrigerant discharge pipe and the refrigerant suction pipe of the compressor, and the inter-unit pipe is a high-pressure gas pipe connected to the refrigerant discharge pipe, A low pressure gas pipe connected to the refrigerant suction pipe and a liquid pipe connected to the other end of the outdoor heat exchanger are configured. One end of the indoor heat exchanger is connected to the high-pressure gas pipe and the low-pressure gas pipe via the high-pressure gas branch pipe and the low-pressure gas branch pipe, respectively, and the other end is connected to the liquid pipe via the liquid branch pipe. A first on-off valve and a second on-off valve are provided in the gas branch pipe and the low-pressure gas branch pipe, respectively.
In this type, generally, two electromagnetic on-off valves (for example, a third on-off valve and a fourth on-off valve) are connected in parallel to one end of the outdoor heat exchanger, and the third on-off valve is connected to the refrigerant discharge pipe of the compressor. And the fourth on-off valve is connected to the refrigerant suction pipe.
Japanese Patent No. 2804527

  However, in the conventional configuration, when switching the flow path on the one end side of the outdoor heat exchanger, the third on-off valve is fully opened at the same time, the fourth on-off valve is fully closed, or the fourth on-off valve is fully opened. The control is such that the 3 on-off valve is fully closed. In particular, in the air conditioner having the above-described configuration, when the outdoor heat exchanger is switched from the condenser (high pressure state) to the evaporator (low pressure state), that is, from the cooling main operation to the heating main operation in the air conditioning system. In the case of switching, there is a problem that the flow of the refrigerant in the vicinity of the outdoor heat exchanger changes in a pulsed manner due to switching control of the third on-off valve and the fourth on-off valve, and vibrations, noises, etc. are generated.

  Therefore, an object of the present invention is to solve the problems of the above-described conventional technology, and for example, even when switching from cooling-based operation to heating-based operation, generation of vibration, noise, and the like can be suppressed. An object is to provide an air conditioner.

In the present invention, an outdoor unit including a compressor, an outdoor heat exchanger, and an outdoor expansion valve is connected to a plurality of indoor units including an indoor heat exchanger and an indoor expansion valve by inter-unit piping, and the outdoor heat One end of the exchanger is alternatively branched and connected to the refrigerant discharge pipe and the refrigerant suction pipe of the compressor, the inter-unit pipe is connected to the refrigerant discharge pipe, and the refrigerant suction A low-pressure gas pipe connected to a pipe and a liquid pipe connected to the other end of the outdoor heat exchanger, and one end of the indoor heat exchanger is connected to the high-pressure gas pipe and the low-pressure gas pipe, Each is connected via a high-pressure gas branch pipe and a low-pressure gas branch pipe, the other end is connected to the liquid pipe via a liquid branch pipe, and an open / close valve is provided in each of the high-pressure gas branch pipe and the low-pressure gas branch pipe. Simultaneous cooling of multiple indoor units Alternatively, in the air conditioner configured to be capable of heating operation, or to be able to perform both of the cooling operation and the heating operation, one end of the outdoor heat exchanger is connected to the refrigerant discharge pipe and the refrigerant of the compressor. A single flow path switching valve that is alternatively branched and connected to the suction pipe is provided. The flow path switching valve accommodates a movable member in the valve body, and the refrigerant flow path is moved by pushing of the movable member. In addition to being configured to be switchable, a pilot valve is provided, and by switching the pilot valve, the movable member is configured to be able to be pushed using the high-pressure refrigerant in the high-pressure gas pipe.
In this configuration, since the movable member can be pushed by using the high-pressure refrigerant in the high-pressure gas pipe by switching the pilot valve, the switching operation of the movable member is performed slowly. Even when the operation is switched from the operation to the heating-based operation, the pressure balance is smoothly performed, and the generation of vibration, noise, and the like is suppressed.

  In this case, the flow path switching valve is constituted by a four-way valve, and among the four ports of the four-way valve, the first port is connected to one end of the outdoor heat exchanger, and the second port is the high-pressure gas. A third port may be connected to the low-pressure gas pipe, and a fourth port may be closed. Further, the first and third ports of the four-way valve may be connected by a connection pipe provided with an on-off valve.

  In the present invention, even when switching from cooling-based operation to heating-based operation, generation of vibration, noise, and the like is suppressed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG.1 and FIG.2 is a circuit diagram which shows one Embodiment of the air conditioning apparatus which concerns on this invention. The air conditioner 1 includes a plurality of (for example, two) outdoor units 2A and 2B and a plurality of (for example, two) indoor units 3A and 3B.
The inter-unit piping 5 that connects the outdoor units 2A, 2B and the indoor units 3A, 3B includes a low-pressure gas pipe 6, a high-pressure gas pipe 7, and a liquid pipe 8. The air conditioner 1 includes the indoor unit 3A. 3B can be simultaneously operated for cooling or heating, or can be implemented by mixing these cooling and heating operations.

  The indoor unit 3A includes an indoor heat exchanger 10 and an indoor expansion valve 11. One end of the indoor heat exchanger 10 is connected to the liquid pipe 8 via a liquid branch pipe 18 provided with the indoor expansion valve 11. Connected. A branch pipe 12 is connected to the other end of the indoor heat exchanger 10, and the branch pipe 12 branches into a high-pressure gas branch pipe 12A and a low-pressure gas branch pipe 12B. The high-pressure gas branch pipe 12 </ b> A is connected to the high-pressure gas pipe 7 via the first on-off valve 13, and the low-pressure gas branch pipe 12 </ b> B is connected to the low-pressure gas pipe 6 via the second on-off valve 14.

  The indoor unit 3A is provided with a temperature sensor that detects the inlet / outlet temperature and room temperature of the outdoor heat exchanger 21, a pressure sensor that detects the refrigerant pressure in the indoor heat exchanger 21, and the like. An indoor control device (not shown) for inputting the result and controlling the indoor unit 3A is provided. In addition, since the indoor unit 3B has substantially the same configuration as the indoor unit 3A, the same portions are denoted by the same reference numerals, and description thereof is omitted.

  The outdoor unit 2A includes a variable capacity compressor (DC inverter compressor) 20A, constant capacity compressors (AC compressors) 20B1 and 20B2, an outdoor heat exchanger 21, an outdoor expansion valve 22, and a receiver. It is generally composed of a tank 23 and the like. Hereinafter, the compressors 20 </ b> A, 20 </ b> B <b> 1, 20 </ b> B <b> 2 are referred to as the compressors 20 when it is not necessary to distinguish between them.

  In the outdoor unit 2A, the compressors 20A, 20B1, and 20B2 are connected in parallel, and the refrigerant suction pipe 30 that is commonly connected to the suction ports of the compressors 20A, 20B1, and 20B2 is connected to the low-pressure gas pipe 6 via the accumulator 24. Connected to. The refrigerant discharge pipe 31 connected to the discharge ports of the compressors 20A, 20B1, and 20B2 branches into two via the oil separator 25, and one refrigerant discharge branch pipe 31A is connected to the high-pressure gas pipe 7. The other refrigerant discharge branch pipe 31B is connected to the outdoor heat exchanger 21.

  Here, the refrigerant discharge branch pipe 31 </ b> B is provided with a switching valve 40, and when the switching valve 40 is opened, the refrigerant discharged from the compressor 20 is supplied to the outdoor heat exchanger 21. Further, the refrigerant discharge branch pipe 31B is provided with a four-way valve (flow path switching valve) 41 between the switching valve 40 and the outdoor heat exchanger 21, and the four-way valve 41 is connected to the outdoor heat exchanger 21. As seen, one end of the outdoor heat exchanger 21 is connected to one of the refrigerant discharge branch pipe 31B and the refrigerant discharge branch pipe 31A connected to the switching valve 40 or the heating path pipe 32 connected to the suction pipe 30 of the compressor 20. It functions as a switching valve for selectively switching.

As shown in FIGS. 3 and 4, the four-way valve 41 includes a four-way valve main body 143 having a movable member 141 and a pilot valve 145, which are respectively connected via three supply pipes 147, 148, and 149. It is connected. The high pressure pipe P of the pilot valve 145 is connected to the high pressure gas pipe 7 upstream of the switching valve 40 as shown in FIG.
The four-way valve main body 143 has four first to fourth ports A to D, and the first port A is connected to one end of the outdoor heat exchanger 21 as shown in FIG. The port B is connected to the high-pressure gas pipe 7, the third port C is connected to the low-pressure gas pipe 6, and the fourth port D is closed by a sealing plug 150 (FIG. 3).
As shown in FIG. 2, the first and third ports A and C of the four-way valve 41 are connected by a connecting pipe 163 provided with an on-off valve 161 having a relatively small diameter.

As shown in FIG. 2, the other end of the outdoor heat exchanger 21 includes an outdoor expansion valve 26, a receiver tank 23, a trap pipe 27, and an auxiliary cooling circuit 28 for adjusting the flow rate of the refrigerant supplied to the outdoor heat exchanger 21. And is connected to the liquid pipe 8 through a pipe.
The auxiliary cooling circuit 28 auxiliary cools the liquid refrigerant flowing through the refrigerant pipe 33 that connects the receiver tank 23 and the liquid pipe 8, and more specifically, the liquid between the receiver tank 23 and the liquid pipe 8. There is a so-called double pipe heat exchanger in which a part of the pipe 33 through which the refrigerant passes and a part of the branch pipe 34 through which the refrigerant branches from the pipe 33 and passes through the expansion valve 29 are constituted by double pipes. Applied. The branch pipe 34 is connected to the refrigerant suction pipe 30 of the compressor 20 via a refrigerant pipe 35 connected to the auxiliary cooling circuit 28, and the refrigerant that has passed through the branch pipes 34 and 35 is returned to the suction port of the compressor 20. It is.

  The oil separator 25 has a refrigerant return pipe 45 for returning oil to the refrigerant suction pipe of the compressor 20 and an oil balance pipe for connecting the oil separator 25 and the oil separator 25 of the other outdoor unit 2B. 46 is connected. The oil balance pipe 46 is connected to the oil separator 25 of another outdoor unit 2B via an oil pipe 47, and between the oil separators 25 of the outdoor units 2A and 2B via the oil balance pipe 46 and the oil pipe 47. The oil flows back and forth, and the balance of the amount of oil stored in each oil separator 25 is ensured.

The outdoor unit 2A includes an outdoor control device 100 that controls the entire outdoor unit 2A. Since the outdoor unit 2B has the same configuration as that of the outdoor unit 2A, the same portions are denoted by the same reference numerals, and redundant description is omitted.
Here, any one of the outdoor units 2A and 2B functions as a master unit, and the outdoor control device 100 of the master unit performs other outdoor controls based on a user instruction input via a remote controller (not shown). It communicates with the apparatus 100 and the indoor control apparatus mentioned above, and performs operation control of this air conditioning apparatus 1 whole.

Next, the operation of the air conditioner 1 will be described.
When all the indoor units 3A and 3B are cooled at the same time, as shown in FIG. 1, in each of the outdoor units 2A and 2B, the switching valve 40 is opened and the four-way valve 41 is controlled to be switched to the solid line position. In the units 3A and 3B, the first on-off valve 13 is closed, and the second on-off valve 14 and the third on-off valve 17 are opened. In this case, as indicated by solid arrows, the refrigerant discharged from the compressor 20 is supplied to the outdoor heat exchanger 21 via the oil separator 25, where it dissipates and condenses to become liquid refrigerant, and the receiver tank 23 and auxiliary cooling The liquid 28 is supplied through the circuit 28. In the indoor units 3A and 3B, the liquid refrigerant is supplied to the indoor heat exchanger 10 via the liquid pipe 8 via the expansion valve 11, where it absorbs and evaporates to become a low-temperature and low-pressure gas refrigerant. The gas is supplied to the low-pressure gas pipe 6 through the on-off valve 14 and the third on-off valve 17.
The gas refrigerant supplied to the low-pressure gas pipe 6 is compressed again by the compressor 20 through the suction pipes 30 of the outdoor units 2A and 2B. As a result, all the indoor units 3A and 3B can simultaneously perform the cooling operation.

  When all the indoor units 3A and 3B are operated simultaneously, the switching valve 40 is closed and the four-way valve 41 is controlled to be switched to the broken line position in each outdoor unit 2A and 2B. 13 is opened, and the second on-off valve 14 and the third on-off valve 15 are closed. In this case, the high-temperature and high-pressure gas refrigerant discharged from the compressor 20 is supplied to the high-pressure gas pipe 7 via the oil separator 25 as indicated by broken line arrows in FIG. In the indoor units 3A and 3B, the gas refrigerant is supplied to the indoor heat exchanger 10 through the high-pressure gas pipe 7, where after the heat is radiated and condensed to become liquid refrigerant, the refrigerant is passed through the expansion valve 11. It is supplied to the liquid pipe 8. The liquid refrigerant supplied to the liquid pipe 8 is supplied to the outdoor heat exchanger 21 through the refrigerant pipes 33 and the receiver tank 23 of the outdoor units 2A and 2B, where it absorbs heat and evaporates, where It becomes a gas refrigerant and is compressed again by the compressor 20 through the suction pipe 30. Thereby, the heating operation can be simultaneously performed in all the indoor units 3A and 3B.

Further, when performing a mixed operation of heating operation and cooling operation, for example, when the indoor unit 3A is operated for heating and the indoor unit 3B is operated for cooling, the outdoor units 2A and 2B are controlled in the same manner as in the above-mentioned simultaneous heating operation. On the other hand, in the indoor unit 3A, the first on-off valve 13 is closed, the second on-off valve 14 and the third on-off valve 17 are opened, and in the indoor unit 3B, the first on-off valve 13 is opened, and the second on-off valve 14 is opened. And the 3rd on-off valve 17 closes. In this case, high-temperature and high-pressure gas refrigerant is supplied from the outdoor units 2A and 2B to the high-pressure gas pipe 7, and in the indoor unit 3A, gas refrigerant is supplied to the indoor heat exchanger 10 via the high-pressure gas pipe 7. After being radiated / condensed to form a liquid refrigerant, it is supplied to the liquid pipe 8 via the expansion valve 11.
A part of the liquid refrigerant supplied to the liquid pipe 8 returns to the outdoor units 2A and 2B, absorbs heat and evaporates in the outdoor heat exchanger 21, and becomes a low-temperature and low-pressure gas refrigerant.

  On the other hand, the remainder of the liquid refrigerant supplied to the liquid pipe 8 is supplied to the indoor heat exchanger 10 of the indoor unit 3B, where it absorbs heat and evaporates to become a low-temperature low-pressure gas refrigerant, and then the second on-off valve 14 And is supplied to the low-pressure gas pipe 6 via the third on-off valve 17. The refrigerant supplied to the low-pressure gas pipe 6 is compressed again by the compressor 20 through the suction pipe 30 together with the gas refrigerant passed through the outdoor heat exchanger 21. Thereby, mixed operation of heating operation and cooling operation can be performed for each of the indoor units 3A and 3B.

In FIG. 1, two indoor units 3 are connected. In practice, however, three or more indoor units 3 are generally connected.
In this case, in the above mixed operation, there may be a case where the total cooling request on the indoor unit 3 side exceeds or falls below the total heating request. When the total cooling requirement exceeds the heating total requirement, so-called cooling is mainly performed. In this case, one end of the outdoor heat exchanger 21 of any of the outdoor units 2 is switched to the above-described four-way valve 41. May be connected to the high pressure gas pipe 7 to function as a condenser (high pressure state).
On the other hand, when the total request for cooling is lower than the total request for heating, a so-called heating operation is performed. In this case, one end of the outdoor heat exchanger 21 of any one of the outdoor units 2 is connected to the four-way valve 41 described above. May be connected to the low pressure gas pipe 6 to function as an evaporator (low pressure state).

Here, switching of the four-way valve 41 will be described with reference to FIGS. 3 and 4.
When the pilot valve 145 is excited and the valve body 145a is moved to the position of FIG. 3, a part P of the high-pressure refrigerant flowing from the high-pressure gas pipe 7 upstream of the switching valve 40 passes through the supply pipe 149 and the four-way valve body. 143 flows into the inside of the right side of the figure, and the movable member 141 is moved to the position shown. In this state, referring to FIG. 2, among the four ports A to D of the four-way valve body 143, the first port A and the second port B communicate with each other, and at the same time, the third port C and the fourth port D. And communicate. However, the fourth port D is closed with the sealing plug 150. When the first port A and the second port B communicate with each other, one end of the outdoor heat exchanger 21 of the outdoor unit 2 is connected to the high-pressure gas pipe 7, and the outdoor heat exchanger 21 functions as a condenser.

  When the pilot valve 145 is excited and the valve body 145a is moved to the position shown in FIG. 4, a part P of the high-pressure refrigerant flowing from the high-pressure gas pipe 7 upstream of the switching valve 40 passes through the supply pipe 148 and the four-way valve body. 143 flows into the left side in the figure, and the movable member 141 is moved to the position shown. In this state, referring to FIG. 2, among the four ports A to D of the four-way valve body 143, the first port A and the third port C communicate with each other, and at the same time, the second port B and the fourth port D. And communicate. However, the fourth port D is closed with the sealing plug 150. When the first port A and the third port C communicate with each other, one end of the outdoor heat exchanger 21 of the outdoor unit 2 is connected to the low-pressure gas pipe 6, and the outdoor heat exchanger 21 functions as an evaporator.

  By the way, in this kind of thing, when switching the outdoor heat exchanger 21 from a condenser (high pressure state) to an evaporator (low pressure state), that is, from the cooling main operation to the heating main operation. In the case of changing, vibration, noise, and the like due to switching of the refrigerant flow are likely to occur particularly in the vicinity of the outdoor heat exchanger 21.

In the present embodiment, in the above switching, that is, when the outdoor heat exchanger 21 is shifted from the condenser (high pressure state) to the evaporator (low pressure state), first, the small-diameter on-off valve 161 (FIG. 2) is turned on. Open and communicate with the port A of the four-way valve 41 in the high pressure state and the port C in the low pressure state to achieve a slight pressure balance, and then switch the four-way valve 41 from the solid line position switching state to the broken line position. Switch to state.
Since the switching of the four-way valve 41 is performed by the four-way valve 41 having the pilot valve 145 as described above, the movable member 141 that operates using the refrigerant pressure is pushed slowly. Compared with a simple on / off valve having a conventional configuration, a very smooth switching operation is realized. FIG. 5 shows the refrigerant pressure change at the time of switching. Conventionally, the pressure change occurred at a stroke as shown by the broken line, but in this embodiment, the pressure change becomes gentle as shown by the solid line.
Therefore, the occurrence of vibration, noise, and the like due to switching of the refrigerant flow in the vicinity of the outdoor heat exchanger 21 is sufficiently suppressed.

  Moreover, in this embodiment, since the outdoor heat exchanger 21 is switched from the condenser (high pressure state) to the evaporator (low pressure state) by the single four-way valve 41, the outdoor heat exchanger 21 is conventionally used. It is not necessary to provide two open / close valves in parallel at one end of the switch, and the number of valves can be reduced and the control thereof can be simplified.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this. In the above-described embodiment, the general four-way valve 41 is used as the flow path switching valve. However, the present invention is not limited to this, and for example, a pilot valve is provided. It is obvious that any switching valve may be used as long as it can push the movable member of the valve body.

It is a refrigerant circuit figure showing one embodiment of the air harmony device concerning the present invention. It is a refrigerant circuit figure of an outdoor unit. It is sectional drawing which shows a four-way valve. It is sectional drawing which similarly shows a four-way valve. It is a figure which shows the refrigerant | coolant pressure change of the outdoor heat exchanger vicinity at the time of four-way valve switching.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2A, 2B Outdoor unit 3A, 3B Indoor unit 5 Inter-unit piping 6 Low pressure gas pipe 7 High pressure gas pipe 8 Liquid pipe 10 Indoor heat exchanger 11 Indoor expansion valve 12A High pressure gas branch pipe 12B Low pressure gas branch pipe 18 Liquid Branch pipe 20 Compressor 21 Outdoor heat exchanger 41 Four-way valve 141 Movable member 143 Four-way valve body 145 Pilot valve

Claims (3)

An outdoor unit having a compressor, an outdoor heat exchanger and an outdoor expansion valve, and a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve are connected by inter-unit piping, and one end of the outdoor heat exchanger However, the refrigerant discharge pipe and the refrigerant suction pipe of the compressor are alternatively branched and connected, and the inter-unit pipe is connected to the high-pressure gas pipe connected to the refrigerant discharge pipe and the refrigerant suction pipe. A low-pressure gas pipe and a liquid pipe connected to the other end of the outdoor heat exchanger, and one end of the indoor heat exchanger is branched into the high-pressure gas pipe and the low-pressure gas pipe, respectively. A pipe and a low-pressure gas branch pipe, the other end is connected to the liquid pipe via a liquid branch pipe, and an open / close valve is provided in each of the high-pressure gas branch pipe and the low-pressure gas branch pipe. Cooling operation of the indoor unit at the same time or And tufts can be operated, or, in the air conditioner configured to be implemented by mixed heating operation and these cooling operation,
A single flow path switching valve for branching and connecting one end of the outdoor heat exchanger to the refrigerant discharge pipe and the refrigerant suction pipe of the compressor;
The flow path switching valve houses a movable member in the valve body, and is configured to be able to switch the refrigerant flow path by pushing the movable member, and includes a pilot valve, and the high pressure gas is switched by switching the pilot valve. An air conditioner configured to be able to push the movable member using a high-pressure refrigerant in a pipe.   The flow path switching valve is constituted by a four-way valve. Of the four ports of the four-way valve, a first port is connected to one end of the outdoor heat exchanger, and a second port is connected to the high-pressure gas pipe. The air conditioning apparatus according to claim 1, wherein the third port is connected to the low-pressure gas pipe, and the fourth port is closed.   The air conditioner according to claim 2, wherein the first and third ports of the four-way valve are connected by a connecting pipe having an on-off valve.

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