JP2007322006A - Multi-room type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine the direction of a refrigerant flowing into an indoor expansion valve in cooling, and to reduce refrigerant noise generated in passing through the indoor expansion valve regardless of an operating state of an indoor unit in heating. <P>SOLUTION: In the indoor unit of the multi-room type air conditioner, a front panel 3 provided with suction openings 3a, 3b its front face and top face, and a supply opening 3c at its lower part is mounted on a base 2. The base 2 is provided with heat exchangers 4, 4a vertically arranged in stages on its front face, and a cross flow fan 5 is rotatably journaled at its back face. The indoor expansion valve 6, and a first refrigerant pipe 7 and a second refrigerant pipe 8 disposed at the front and back of the indoor expansion valve are disposed in a back space formed by a constricted part 2a of the base 2, the first refrigerant pipe 7 is used as a trap in which the refrigerant of liquid phase easily accumulates, and is connected with the indoor expansion valve 6 in an opened state, disposed in the indoor unit of which an operation is stopped in heating, and the second refrigerant pipe 8 is positioned to determine the direction of the refrigerant flowing into the indoor expansion valve 6 laterally or downward in cooling. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multi-room air conditioner, and more particularly to a multi-room air conditioner that can reduce refrigerant noise that occurs when passing through an indoor expansion valve.

  In a multi-room air conditioner, an outdoor unit (not shown) and a plurality of indoor units are connected by a refrigerant pipe to constitute a refrigeration cycle. As shown in FIG. 8, for example, one indoor unit of a multi-room type air conditioner is provided with an indoor heat exchanger 4 and an indoor expansion valve 6 that arbitrarily adjusts the refrigerant flow rate of the refrigeration cycle. There is something to be. When the refrigerant passing through the indoor expansion valve 6 (throttle mechanism) is in a gas-liquid two-phase state composed of a gas phase and a liquid phase, refrigerant noise is generated and noise is generated when passing through the indoor expansion valve 6 (throttle mechanism). .

  Since the indoor expansion valve 6 is throttled during cooling, the refrigerant flowing into the indoor expansion valve 6 usually changes from a liquid phase state to a gas-liquid two phase state. At this time, when the inlet of the indoor expansion valve 6 is downward as shown in FIG. 8, the refrigerant flows upward, the gas-liquid two-phase refrigerant flows into the indoor expansion valve 6, and the gas-liquid two-phase refrigerant having a high gas ratio is obtained. A particularly loud refrigerant noise is generated when inflowing. On the other hand, in a multi-room air conditioner, for example, a building multi-air conditioner, the indoor expansion valve 6 cannot be throttled during heating. Therefore, the refrigeration cycle works even when the operation of the indoor unit is stopped. Into the gas-liquid two-phase refrigerant flows. At this time, a refrigerant sound is generated while the operation of the indoor unit is stopped.

  In order to reduce this noise, for example, as shown in FIG. 9, a constricted portion 2 a is provided on the upper back surface (base 2) of the housing 1 provided with the indoor heat exchangers 4, 4 a and the crossflow fan 5, etc. In the constricted portion 2a, a diaphragm mechanism 10 serving as a noise generation source is disposed (for example, see Patent Document 1).

  FIG. 10 shows another example of reducing refrigerant noise. This is a configuration in which a tee 16 is provided between the capillary tube 14 (throttle mechanism) and the evaporator 15 and a closing portion 17 is provided at one end of the tee 16. (For example, refer to Patent Document 2). With such a configuration, the refrigerant jetted from the capillary tube 14 (throttle mechanism) into the teeth 16 does not flow into the evaporator 15 in the gas-liquid two-phase state, but strikes the closed portion 17 and is agitated. Is subdivided and flows into the evaporator 15 in a gas-liquid mixed state, so that the generation of refrigerant noise at the inlet and inside of the evaporator 15 can be suppressed.

  FIG. 11 shows yet another example, in which the porous bodies 18 and 18a are inserted before and after the expansion valve 105 (throttle mechanism) to change the refrigerant flow state so as to reduce refrigerant noise and pipe vibration. (For example, refer to Patent Document 3). With such a configuration, the refrigerant 106 in the gas-liquid two-phase state changes to a gas-liquid mixed state when passing through the porous bodies 18 and 18a before and after the expansion valve 105 (throttle mechanism). And piping vibration can be reduced.

  However, in the example of FIG. 9, the refrigerant sound itself generated from the throttle mechanism 10 could not be reduced. In the example of FIGS. 10 and 11, the gas-liquid two-phase state can be changed to the gas-liquid mixed state, but the refrigerant direction in the gas-liquid two-phase state flowing into the throttle mechanism during cooling is not considered. Therefore, depending on the direction of the refrigerant, the generation of refrigerant noise passing through the throttle mechanism could not be sufficiently suppressed.

Furthermore, since it is not assumed that the indoor unit is stopped during heating of the multi-room air conditioner, the gas-liquid two-phase refrigerant having a high gas ratio passes through the throttle mechanism on the inlet side of the throttle mechanism. In this case, the generation of refrigerant noise could not be sufficiently suppressed. Therefore, depending on the direction of the refrigerant flowing into the throttle mechanism during cooling and the operating state of the indoor unit during heating, it is insufficient as a noise countermeasure.
JP-A-7-229636 (2nd page, FIG. 2) Japanese Utility Model Publication No. 5-8357 (first page, FIG. 2) Japanese Patent Laid-Open No. 7-146032 (first page, FIG. 1)

  In view of the above problems, the present invention determines the direction of the refrigerant flowing into the indoor expansion valve during cooling, and occurs when the refrigerant passes through the indoor expansion valve regardless of the operating state of the indoor unit during heating. An object of the present invention is to provide a multi-room air conditioner that further reduces refrigerant noise.

  The present invention has been made in order to solve the above-described problems. The refrigerant includes an outdoor unit including a compressor, a four-way valve, and an outdoor heat exchanger, and a plurality of indoor units including an indoor heat exchanger and an indoor expansion valve. A first refrigerant pipe connected between the indoor heat exchanger and the indoor expansion valve; and a second refrigerant pipe connecting the indoor expansion valve and the outdoor heat exchanger. In the multi-room air conditioner, the first refrigerant pipe is a trap, is connected to the indoor expansion valve in an open state provided in an indoor unit that is shut down during heating, and the second refrigerant pipe is The refrigerant flowing into the expansion valve has a lateral direction or a downward direction.

  In addition, the first refrigerant pipe is provided with a connection part in the middle, and a pipe thinner than the pipe connecting the indoor heat exchanger and the connection part is connected between the connection part and the indoor expansion valve. It becomes the composition which becomes.

  In addition, an expansion valve unit including the first refrigerant pipe and the indoor expansion valve is installed outside the indoor unit.

  If the multi-chamber air conditioner according to the present invention, the refrigerant in the gas-liquid two-phase state flowing into the indoor expansion valve at the time of heating, which is the source of refrigerant sound, is circulated through the first refrigerant pipe of the trap. Since the liquid refrigerant is easily collected in the first refrigerant pipe of the trap, the refrigerant in the liquid phase flows into the indoor expansion valve as it is and the generation of refrigerant noise in the indoor expansion valve is suppressed. Also, the refrigerant in the gas-liquid two-phase state that flows into the indoor expansion valve during cooling, which is the source of refrigerant noise, is circulated through the second refrigerant pipe, and the refrigerant flowing from the second refrigerant pipe into the indoor expansion valve is directed sideways. Or since it is made downward, generation | occurrence | production of the refrigerant | coolant sound in an indoor expansion valve is suppressed.

  Moreover, since the first refrigerant pipe is introduced into the indoor expansion valve through a pipe that is narrower than the pipe connecting the indoor heat exchanger and the connecting portion, the liquid-phase refrigerant is more likely to stay. The occurrence of refrigerant noise in the indoor expansion valve is suppressed. Furthermore, since the expansion valve unit including the first refrigerant pipe and the indoor expansion valve is installed outside the indoor unit, the refrigerant sound is not amplified by the casing of the indoor unit, and the quieter A driving environment can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same components as those in the background art will be described with the same reference numerals.

  FIG. 1 is a side view of the interior of an indoor unit of a multi-room air conditioner according to the present invention. A casing 1 of the indoor unit is composed of a base 2 forming a back surface and a front panel 3 forming a front surface. Composed. The base 2 supports an indoor heat exchanger 4 whose upper part is inclined rearward and an indoor heat exchanger 4a erected substantially vertically at the lower part of the indoor heat exchanger 4 in two upper and lower stages. A cylindrical crossflow fan 5 driven by a motor is rotatably supported on the back surface of the exchanger 4a, and a blower outlet 3c is formed at the lower portion of the crossflow fan 5.

  A constricted portion 2a is formed at the upper back of the base 2 so that a gap is created when the indoor unit is installed on the wall surface. The front panel 3 is formed with lattice-like suction ports 3a and 3b on the front and upper surfaces thereof. The constricted portion 2a formed on the upper back surface of the base 2 has an indoor expansion valve 6 according to the present invention, and a trap-shaped first end connected to the indoor heat exchanger 4a and the other end connected to the indoor expansion valve 6. One refrigerant pipe 7 and a second refrigerant pipe 8 having one end connected to the indoor expansion valve 6 and the other end connected to an outdoor unit (outdoor heat exchanger) (not shown) are arranged.

  FIG. 2 is an enlarged view of the form of the first refrigerant pipe 7 and the second refrigerant pipe 8 connected to the indoor expansion valve 6 and the indoor expansion valve 6. The first refrigerant pipe 7 is a trap in which liquid-phase refrigerant is likely to accumulate. It has become. Specifically, one side of piping 7a (for example, 6.35Φ piping) from the indoor heat exchanger 4a is bent into a hairpin shape (inverted U shape), and the tip portion is a T-shaped tube 7b (constitutes a connecting portion). Is connected to one end of the T-tube 7b, a closed tube 7c having one end closed is connected to the other end of the T-tube 7b, and a small-diameter portion 7d (for example, between the intermediate connection end of the T-tube 7b and the indoor expansion valve 6). , 4.76Φ thin piping).

  With such a piping configuration, when the operation of the indoor unit is stopped during heating, the refrigerant flow from the indoor heat exchanger 4a to the indoor expansion valve 6 is in a gas-liquid two-phase state with a high gas ratio. However, liquid phase refrigerant is applied to the lower part of the first refrigerant pipe 7 serving as a trap (the part extending from the tip of the pipe 7a to the T-shaped tube 7b, the closed tube 7c, and the small diameter portion 7d) due to the influence of gravity. Since it is easy to accumulate, the inlet side of the indoor expansion valve 6 is not in a gas-liquid two-phase refrigerant state with a high gas ratio, and generation of refrigerant noise in the indoor expansion valve can be suppressed.

  On the other hand, the second refrigerant pipe 8 heading from the indoor expansion valve 6 (refrigerant outlet at the time of heating) to the outdoor unit (outdoor heat exchanger) is formed in an L-shape in the vicinity of the indoor expansion valve 6. . The second refrigerant pipe 8 has a transverse refrigerant direction flowing into the indoor expansion valve 6 during cooling, and the thin pipe (first refrigerant pipe 7), which is the narrow diameter portion 7d, is a refrigerant flowing into the indoor expansion valve 6 during heating. They are connected so that the direction is upward. In the indoor expansion valve 6 shown in FIG. 3, the refrigerant during cooling enters the valve chamber 6a from the lateral direction and flows in the direction b through the throttle 6b, and the refrigerant during heating passes through the throttle 6b from below. 6a enters and flows in the direction a.

  With such a piping configuration, even when the refrigerant flow from the outdoor unit is in a gas-liquid two-phase state at the time of cooling, the liquid-phase refrigerant flows under the influence of gravity at the lower part of the L-shaped riser. Since the refrigerant flow toward the indoor expansion valve 6 is oriented sideways, the generation of refrigerant noise in the indoor expansion valve can be suppressed.

  If the first refrigerant pipe 7 connected to the indoor expansion valve 6 is a straight pipe so that the refrigerant during heating flows in the direction b from the throttle portion 6b in the direction opposite to that in FIG. Sound generated in the throttle portion 6b passes downward and is transmitted to the refrigerant pipe and the indoor heat exchanger 4 and is likely to be noise. However, in the present invention, as described above, the first refrigerant pipe 7 is used as a trap. The refrigerant flows in the direction a and the liquid-phase refrigerant is easily accumulated, so that it is difficult to transmit sound and noise. Occurrence is suppressed.

  In FIG. 4, the indoor expansion valve 6 of FIG. 2 described above is set in the horizontal direction, the first refrigerant pipe 7 is used as a trap in which liquid-phase refrigerant tends to accumulate, and the second refrigerant pipe 8 is formed in an L shape from the indoor expansion valve 6. This is an example of starting up. Specifically, one side of the pipe 7a from the indoor heat exchanger 4a is bent into a hairpin shape (inverted U shape), and its tip is connected to one end of a T-shaped tube 7b (which constitutes a connecting portion). A closed tube 7c whose one end is closed is connected to the other end of the character tube 7b, and a small diameter portion 7d raised in an L shape from the intermediate connection end of the T tube 7b is connected to the indoor expansion valve 6. Yes.

  In such a configuration, the indoor expansion valve 6 has a piping configuration disposed below the T-shaped tube 7b. Therefore, when the operation of the indoor unit is stopped during heating, the indoor expansion valve 6 is connected to the indoor expansion valve 6a. Even if the refrigerant flow to 6 is in a gas-liquid two-phase state, the portion of the first refrigerant pipe 7 that forms the trap shown in FIG. Since liquid-phase refrigerant is likely to accumulate, the inlet side of the indoor expansion valve 6 does not enter a gas-liquid two-phase refrigerant state with a high gas ratio, and refrigerant noise is generated in the indoor expansion valve, as in the example shown in FIG. Can be suppressed.

  In FIG. 4, one side of the pipe 7 a from the indoor heat exchanger 4 a is bent into a hairpin shape (inverted U shape) and its tip is connected to one end of a T-shaped tube 7 b (connecting portion is configured). However, the same effect as described above can be obtained by directly connecting the tip of the pipe 7a to one end of the T-shaped pipe 7b without bending one side of the pipe 7a.

  On the other hand, in the second refrigerant pipe 8 from the indoor expansion valve 6 to the outdoor unit (outdoor heat exchanger), the direction of the refrigerant flowing into the indoor expansion valve 6 during cooling is downward, and the thin pipe that is the small diameter portion 7d is used during heating. It connects so that the refrigerant | coolant direction which flows in into the indoor expansion valve 6 may turn sideways.

  If it is such a piping configuration, as in the example shown in FIG. 2, even when the refrigerant flow from the outdoor unit is in a gas-liquid two-phase state during cooling, at the lower part of the L-shaped rising portion, Liquid phase refrigerant tends to accumulate due to the influence of gravity, and the refrigerant flow toward the indoor expansion valve 6 is directed downward, so that generation of refrigerant noise in the indoor expansion valve can be suppressed.

  FIG. 5 shows the refrigeration cycle of the multi-room air conditioner described above, and has a configuration in which an outdoor unit A and a plurality of indoor units B, C, and D are connected by a circulating refrigerant pipe. The compressor 11 provided in the outdoor unit A, the four-way valve 12 for switching the refrigerant flow corresponding to the operation mode, the outdoor heat exchanger 13, the outdoor expansion valve 19, the indoor expansion valve 6 provided in the indoor unit B, and the indoor heat exchanger 4 4a are sequentially connected by piping, and an indoor unit C and an indoor unit D having the same configuration as the indoor unit B are connected in parallel. In addition, before and after the indoor expansion valve 6 in each indoor unit B, C, D, a first refrigerant pipe 7 and a second refrigerant pipe 8 which are traps provided with a narrow-diameter portion 7d in the middle described above. And are connected.

  Note that FIG. 5 illustrates the case where the indoor unit C and the indoor unit D having the same configuration are connected in parallel to the indoor unit B, but the indoor unit C and the indoor unit D having the same configuration are sequentially connected in series to the indoor unit B. Even if connected, the same effect as described above can be obtained. In this case, when the example shown in FIG. 2 or FIG. 4 is an indoor unit B, the second refrigerant pipe 8 is connected to one end of the indoor heat exchangers 4 and 4a of the next indoor unit C and is connected to the other end. The first refrigerant pipe 7, the indoor expansion valve 6, and the second refrigerant pipe 8 are sequentially connected. Thereafter, similarly, the second refrigerant pipe 8 is connected to one end of the indoor heat exchangers 4 and 4a of the next indoor unit D, and the first refrigerant pipe 7, the indoor expansion valve 6, the second refrigerant pipe 8, and the like from the other end. This can be realized by sequentially connecting to the outdoor heat exchanger 13.

  6 and 7 show a configuration in which the expansion valve unit U composed of the first refrigerant pipe 7 and the indoor expansion valve 6 serving as the trap described above is installed vertically or horizontally outside the indoor unit. It is a thing. 6 corresponds to unitization of the piping configuration of FIG. 2, and FIG. 7 corresponds to unitization of the piping configuration of FIG. 4. With such a configuration, the noise reduction effect can be further enhanced. it can.

It is side sectional drawing of the indoor unit of the multi-room type air conditioner which shows embodiment of this invention. It is an enlarged view which has arranged the principal part of this invention to the vertical direction. It is principal part sectional drawing of the indoor expansion valve concerning this invention. It is an enlarged view which has arranged the principal part of this invention in the horizontal direction. It is a refrigerating cycle figure of the multi-room type air conditioner concerning the present invention. It is a perspective view which shows the installation form of the expansion valve unit by this invention. It is a perspective view which shows another installation form of the expansion valve unit by this invention. It is a front view which shows the outline of the internal structure of the indoor unit of the conventional multi-room type air conditioner. It is a sectional side view of the indoor unit of the air conditioner which shows a prior art example. It is a principal part expanded sectional view of the air conditioner which shows a prior art example. It is a structure sectional view of the conventional expansion valve.

Explanation of symbols

A Outdoor unit B, C, D Indoor unit U Expansion valve unit 1 Housing 2 Base 3 Front panel 4, 4a Indoor heat exchanger 5 Cross flow fan 6 Indoor expansion valve 6a Valve chamber 6b Throttle part 7 First refrigerant piping 7a Piping 7b T-shaped tube 7c Blocking tube 7d Small diameter portion 8 Second refrigerant piping

Claims (3)

  An outdoor unit including a compressor, a four-way valve, and an outdoor heat exchanger, and a plurality of indoor units including an indoor heat exchanger and an indoor expansion valve are connected by a refrigerant pipe, and the indoor heat exchanger and the indoor expansion valve In a multi-chamber air conditioner comprising a first refrigerant pipe connecting between and a second refrigerant pipe connecting between the indoor expansion valve and the outdoor heat exchanger, the first refrigerant pipe is a trap, Connected to the indoor expansion valve in an open state provided in an indoor unit whose operation is stopped during heating, and the second refrigerant pipe is configured such that the direction of the refrigerant flowing into the indoor expansion valve during cooling is horizontal or downward. Multi-room air conditioner.   The first refrigerant pipe is provided with a connection part in the middle, and a pipe thinner than the pipe connecting the indoor heat exchanger and the connection part is connected between the connection part and the indoor expansion valve. The multi-room air conditioner according to claim 1.   The multi-room air conditioner according to claim 1 or 2, wherein an expansion valve unit including the first refrigerant pipe and the indoor expansion valve is installed outside the indoor unit.

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