JP2008145030A - Multi-room air conditioner - Google Patents

Abstract

In a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit, the indoor unit that is stopped or thermo-off when the other indoor units are in a heating operation. In the heat exchanger, the refrigerant is condensed and liquefied to a certain extent, resulting in a two-phase flow of gas and liquid. To prevent the refrigerant from accumulating during heating, an electronic expansion valve, capillary tube, etc. When the refrigerant passes through the throttle portion, there is a problem that the refrigerant state after passing through the throttle portion is disturbed and refrigerant noise is generated.
By providing the receivers 11a and 11b on the heating outlet side of the electronic expansion valves 16a and 16b in the indoor units 2a and 2b, the refrigerant circuit is provided with a portion that rapidly increases the pipe diameter, so that a muffler effect is obtained. The pressure fluctuation can be reduced to prevent the generation of sound, and the noise level itself can be reduced.
[Selection] Figure 3

Description

  The present invention relates to a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit, in the refrigerant circuit of the indoor unit in which other indoor units are stopped during heating operation. It is related with suppression of the refrigerant | coolant sound generated from.

  A conventional multi-room air conditioner will be described with reference to FIG. FIG. 8 is a refrigeration cycle diagram of a multi-room air conditioner. The outdoor unit 1 and the indoor units 2a and 2b are connected by a refrigerant pipe. The outdoor unit 1 includes a compressor 103, a four-way switching valve 104, an outdoor heat exchanger 105, an outdoor fan 106, an outdoor motor 107, an accumulator 108, and the like. An expansion valve 110 and a check valve 111 are parallel to the liquid pipe 109. It is connected to the. The indoor units 2a and 2b include indoor heat exchangers 12a and 12b, indoor fans 13a and 13b, indoor motors 14a and 14b, and the like, and electronic expansion valves 16a and 16b are connected to the liquid pipes 15a and 15b. .

  During the cooling operation, the gas refrigerant discharged from the compressor 103 enters the outdoor heat exchanger 105 through the four-way switching valve 104 and is introduced by the outdoor fan 106 driven by the outdoor motor 107 as indicated by the solid line arrow. It is condensed and liquefied by releasing heat to the outdoor air. This liquid refrigerant enters the indoor units 2a and 2b through a check valve 111 connected in parallel with the expansion valve 110 which is fully opened in order to make the passage resistance as small as possible. And after adiabatic expansion by being throttled by the electronic expansion valves 16a and 16b, the indoor air enters the indoor heat exchangers 12a and 12b, and the indoor air introduced by the indoor fans 13a and 13b driven by the indoor motors 14a and 14b. Evaporates and vaporizes by absorbing heat. The gas refrigerant returns to the outdoor unit 10 and is sucked into the compressor 103 through the four-way switching valve 104 and the accumulator 108.

  At the time of heating operation, the four-way switching valve 4 is switched in reverse to the above, and the gas refrigerant discharged from the compressor 3 passes through the four-way switching valve 104, and the indoor heat in the indoor units 2a and 2b, as indicated by the broken line arrows. The heat exchanger enters the exchangers 12a and 12b and radiates heat to the indoor air introduced by the indoor fans 13a and 13b driven by the indoor motors 14a and 14b. After that, after passing through the electronic expansion valves 16a and 16b that are fully opened to reduce the passage resistance as much as possible, the heat is expanded by adiabatic by being throttled by the expansion valve 110 in the outdoor unit 10, and then enters the outdoor heat exchanger 105. Here, the outdoor fan 106 driven by the outdoor motor 107 absorbs heat from the outdoor air to evaporate. This gas refrigerant returns to the compressor 103 through the four-way switching valve 104 and the accumulator 108.

  The indoor units 2a and 2b can be switched for each indoor unit by operating an individually connected remote controller, and can be switched between operating modes such as cooling, heating, and air flow, and set at room temperature. Automated operation to maintain room temperature.

During heating operation, the room temperature sensor in the indoor unit is lower than the remote control set temperature, the fan is in operation and the room is heated with warm air, the thermo-ON state, the room temperature sensor in the indoor unit is the remote control set temperature Higher, the fan is stopped, and the state where heating is not performed is the thermo OFF state. For example, when the indoor unit 2a is in either the thermo OFF or the air blowing operation stop, and the indoor unit 2b is in the heating operation, The electronic expansion valve 16a in the indoor unit 2a is closed, and the inflow of the refrigerant to the indoor heat exchanger 12a is blocked. However, if the electronic expansion valve 16a is fully closed during the heating operation, the refrigerant accumulates in the indoor heat exchanger 12a. To prevent this, the electronic expansion valve 16a is set to a small opening and a small amount of refrigerant is allowed to flow. However, in order to suppress a small amount of refrigerant flow noise, throttle mechanisms 17a, 17b such as capillary tubes and check valves 18a, 18b are connected in series in parallel with the electronic expansion valves 16a, 16b, and only during heating. A predetermined minute amount of refrigerant is allowed to flow (see, for example, Patent Document 1).
JP-A-7-310962

  However, in the conventional configuration, the refrigerant is condensed and liquefied to some extent in the heat exchanger of the indoor unit that is stopped or thermo-off when other indoor units are in the heating operation, It is not a liquid-phase flow, but is actually a gas-liquid two-phase flow. In this state, if the refrigerant passes through a throttle part such as an electronic expansion valve or capillary tube set to a minute opening in order to flow a predetermined minute refrigerant amount, the refrigerant flow rate increases, so the refrigerant state after passing through the throttle part is The sound of the refrigerant was generated and the sound of the refrigerant was generated, and the sound of the refrigerant was heard even though the operation was stopped. Is not a problem because the noise of the refrigerant is wiped out by the fan blowing sound).

  In addition, since the throttle part through which the refrigerant passes when the operating conditions such as weather conditions and installation conditions change is set to a constant passage resistance in order to flow a predetermined small amount of refrigerant, the flow rate is high under high pressure conditions. There was a problem that the refrigerant sound further increased and the refrigerant noise increased.

  The present invention solves the above-described conventional problems by rectifying the refrigerant state after passing through the throttle portion in an indoor unit that is stopped or thermo-off when another indoor unit is in a heating operation. An object of the present invention is to provide a multi-room air conditioner that suppresses refrigerant noise.

  In order to solve the above conventional problems, the present invention has one outdoor unit and a plurality of indoor units connected to the outdoor unit, and the indoor unit includes an expansion valve provided in a refrigerant circuit. In the multi-chamber air conditioner, a receiver is provided on the heating outlet side of the expansion valve, and since the flow path is widened at the receiver portion, the kinetic energy of the refrigerant is consumed, pressure fluctuation is reduced, and sound is generated. In addition to being prevented from becoming a source, a portion of the refrigerant circuit in the indoor unit that rapidly increases the pipe diameter is provided, so that a muffler effect can be obtained and the noise level itself can be suppressed.

  Also, the receiver is molded into an inverted conical shape, and a pipe connected from the expansion valve to the receiver is formed so as to be connected tangentially to the upper part of the receiver. Therefore, the turbulent flow can be prevented and the generation of refrigerant noise can be suppressed.

  In addition, a spiral groove is formed inside the inverted conical receiver.

  In addition, a spiral coil is built in the inverted conical receiver.

  The refrigerant circuit from the receiver to the heating outlet side connecting pipe is branched into two pipes, a pipe connected to the upper part of the receiver and a pipe connected to the lower part.

The present invention provides a receiver on the outlet side of the expansion valve during heating operation, so that the flow path is widened, so that the kinetic energy of the refrigerant is consumed and the pressure fluctuation is reduced to prevent generation of sound. In addition, since the refrigerant circuit in the indoor unit is provided with a portion that rapidly increases the pipe diameter, a muffler effect can be obtained and the noise level itself can be suppressed.

  In addition, by connecting the pipe connected to the inverted conical receiver in the tangential direction to the upper part of the receiver so that the gas-liquid two-phase flow after passing through the expansion valve flows along the inside of the receiver to the lower part, It can prevent turbulent flow and suppress the generation of refrigerant noise.

  In addition, by forming a spiral groove inside the inverted conical receiver, the flow along the tube wall can be achieved even when the ratio of the gas phase to the liquid phase changes or the flow rate changes. It is possible to prevent turbulent flow and to prevent generation of refrigerant noise.

  In addition, by incorporating a helical coil inside the inverted conical receiver, the same effect as described above can be obtained, and there is no need to form a groove inside the wall surface, thus simplifying the manufacturing process and reducing the cost of the receiver. Can be manufactured.

  In addition, the refrigerant circuit reaching the heating outlet side connection pipe branches into two pipes, one connected to the upper part of the inverted conical receiver and the other connected to the lower part, thereby separating the liquid phase and the gas phase as much as possible. Therefore, it is possible to prevent the generation of the refrigerant sound by preventing the sound from being generated and joining the outside of the indoor unit that is less affected by the sound for the user.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
Claim 1 of the present invention will be described with reference to FIGS. The contents already described above will be omitted with reference to the above description. FIG. 1 is a refrigeration cycle diagram of an air conditioner according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the receiver of the multi-room air conditioner in the first embodiment.

  In FIG. 1, it is assumed that the indoor unit 2a is in the operation stop state or in the thermo OFF state while the indoor unit 2b is in the heating operation with the thermo ON state. Assuming that the indoor unit 2b is in operation, the electronic expansion valve 16a in the indoor unit 2a is fixed at a fine opening set in advance. Since the refrigerant passes through the heat exchanger 12a of the indoor unit 2a and dissipates heat to the indoor air, it is condensed to some extent, but not completely liquefied. At the outlet of the heat exchanger 12a, the gas-liquid two-phase It has become a flow. When passing through the electronic expansion valve 16a that is fixed at a very small opening in this two-phase state, the flow velocity increases, the refrigerant flows in from the inlet of the receiver 11a, and diffuses into the receiver 11a.

  At this time, the refrigerant flows into a place with a wide pipe diameter, and the flow velocity becomes slow, so the refrigerant noise does not increase. Moreover, it can suppress even if a sound generate | occur | produces according to the muffler effect. Then, the refrigerant that dissipates energy in the receiver 11a is converged to the lowermost outlet and flows to the connecting pipe. Here, the gas phase and the liquid phase flow at a constant rate than when the expansion valve passes. Thus, the generation of refrigerant noise is reduced.

(Embodiment 2)
3A and 3B are cross-sectional views of a receiver of a multi-chamber air conditioner according to a second embodiment of the present invention, where FIG. 3A shows a transverse cross section and FIG. 3B shows a vertical cross section. FIG. 4 is a connection configuration diagram of the receiver of the multi-room air conditioner according to the second embodiment of the present invention.

  As shown in FIG. 4, the inlet pipe 22 to the receiver 21 is connected to the upper part of the receiver 21 in the tangential direction. When connected in this way, the refrigerant flows along the inner wall surface of the receiver 21 due to centrifugal force, and flows out smoothly from the outlet 23 at the bottom.

  In the case of a two-phase flow with a large liquid phase, the refrigerant noise causes noise when bubbles that discontinuously collide with each other or collide with a wall surface. When it scatters from the surface, it causes noise, but by making it an inverted conical shape, the speed of flowing to the lower part of the receiver can be reduced and along the inner wall surface, effectively rectifying the two-phase flow And refrigerant noise can be reduced.

(Embodiment 3)
FIG. 5 is a cross-sectional view of a receiver of a multi-chamber air conditioner according to a third embodiment of the present invention, where (a) shows a transverse cross section and (b) shows a vertical cross section. In FIG. 5, a spiral groove 35 is formed on the inner wall surface of the receiver 31.

  By forming such a groove 35, the two-phase flow can be effectively rectified and the refrigerant noise can be reduced even if the refrigerant state changes due to a change in operating conditions.

(Embodiment 4)
FIG. 6 is a cross-sectional view of a receiver of a multi-chamber air conditioner according to a fourth embodiment of the present invention, where (a) shows a transverse cross section and (b) shows a vertical cross section. In FIG. 6, a coil 45 formed in a spiral shape along the inner wall surface is enclosed in the receiver 41, and is fixed inside the receiver. The material is preferably made of a material that is difficult to deform, such as stainless steel.

  The operation in the fourth embodiment is the same as that in the third embodiment described above, and the same effect can be obtained. However, since the width of the coil can be changed without changing the shape of the receiver 41, the indoor units having different capacities are used. In addition, a receiver can be used for general purposes, and the receiver can be manufactured at low cost.

(Embodiment 5)
FIG. 7: is sectional drawing of piping of the vicinity containing the receiver of the multi-chamber type air conditioner in the 4th Embodiment of this invention. In FIG. 7, the receiver 51 is obtained by adding an upper pipe 54 to the receiver in the second to fourth embodiments, and the upper pipe 54 is configured so that the passage resistance is smaller than that of the lower pipe 55.

  The refrigerant that has flowed into the receiver 51 configured as described above can flow the gas phase from the upper pipe 54 and the liquid phase from the lower pipe 55, and the gas-liquid two-phase state in the connection pipe from the receiver outlet 53 can be completely achieved. Therefore, the refrigerant noise can be further reduced.

  Further, in each of the above embodiments, the example of using the stop unit at the time of heating in the multi-room type air conditioner has been described, but the present invention can be similarly used for an outdoor unit having an expansion mechanism.

The block diagram of the refrigerating cycle of the multi-room type air conditioner in Embodiment 1 of this invention Sectional drawing of the receiver of the multi-room air conditioner in Embodiment 1 of this invention Sectional drawing of the receiver of the multi-room type air conditioner in Embodiment 2 of this invention, (a) The figure which shows a cross section, The figure which shows (b) longitudinal section Connection configuration diagram of the receiver of the multi-room air conditioner in Embodiment 2 of the present invention Sectional drawing of the receiver of the multi-chamber type air conditioner in Embodiment 3 of this invention, (a) The figure which shows a cross section, (b) The figure which shows a longitudinal section Sectional drawing of the receiver of the multi-room type air conditioner in Embodiment 4 of this invention, (a) The figure which shows a cross section, (b) The figure which shows a longitudinal section Sectional drawing of the principal part of the receiver vicinity of the multi-room type air conditioner in Embodiment 5 of this invention Refrigeration cycle diagram of a conventional multi-room air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outdoor unit 2a, 2b Indoor unit 103 Compressor 104 Four-way selector valve 105 Outdoor heat exchanger 106 Outdoor fan 107 Outdoor motor 108 Accumulator 109 Liquid pipe 110 Expansion valve 111 Check valve 12a, 12b Indoor heat exchanger 13a, 13b Indoor fan 14a, 14b Indoor motor 15a, 15b Liquid pipe 16a, 16b Electronic expansion valve 11a, 11b, 21, 31, 41, 51 Receiver 22, 32, 42, 52 Receiver inlet 23, 33, 43, 53 Receiver outlet 54 Upper piping 55 Lower piping

Claims (5)

In a multi-room air conditioner having one outdoor unit and a plurality of indoor units connected to the outdoor unit, wherein the indoor unit includes an expansion valve provided in a refrigerant circuit. A multi-room air conditioner comprising a receiver on the heating outlet side. The multi-chamber air conditioner according to claim 1, wherein the receiver is formed in an inverted conical shape, and a pipe connected from the expansion valve is connected in a tangential direction at an upper portion of the receiver. The multi-room air conditioner according to claim 2, wherein a spiral coil is built in the receiver. The multi-chamber air conditioner according to claim 2, wherein a spiral groove is formed inside the receiver. The refrigerant circuit from the receiver to the heating outlet side connection pipe is branched into two pipes, one connected to the upper part of the receiver and the other connected to the lower part. Room type air conditioner.