JP2004301476A - Indoor unit for air conditioning and air conditioner comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indoor unit for air conditioning, reducing the refrigerant flow noise in a restriction mechanism part. <P>SOLUTION: In this indoor unit for air conditioning wherein the indoor heat exchanger 31 for cooling or heating the indoor air and a refrigerant by heat exchanging, is divided into two indoor heat exchanging units 31a, 31b, and the restriction mechanism part 40 is mounted between the indoor heat exchanging units 31a, 31b, the restriction mechanism part 40 comprises a capillary tube 41 for reducing a cross-sectional area of a first refrigerant channel 11b, and a babble growth inhibiting member 42 mounted in a state of being kept into contact with a tip part as a refrigerant outlet of the capillary tube 41. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioning indoor unit configured to be capable of performing a reheat dry operation and an air conditioner including the same, and particularly to a technique suitable for reducing noise during a reheat dry operation.
[0002]
[Prior art]
Conventionally, in order to suppress a decrease in the indoor temperature during the dehumidifying operation, the indoor heat exchanger in the air conditioning indoor unit is divided into two indoor heat exchange units, and a refrigerant pipe connecting the both indoor heat exchange units is provided. There has been known an apparatus provided with an expansion mechanism to enable a reheat dry operation. In such an air conditioning indoor unit, the flow direction of the refrigerant is selectively switched by a four-way valve,
(1) cooling operation and dehumidification operation in which both indoor heat exchange units function as an evaporator,
(2) a heating operation in which both indoor heat exchange units function as condensers;
(3) a reheat dry operation in which one of the two indoor heat exchange units is used as a condenser and the other is used as an evaporator;
Can be implemented.
[0003]
FIG. 9 is a block diagram showing the structure around the indoor heat exchanger of the indoor unit for air conditioning configured to be able to perform the reheat dry operation. In the figure, reference numeral 1 denotes an indoor heat exchanger, and 1a denotes a first indoor heat exchange. The unit, 1b is a second indoor heat exchange unit, 2 is a throttle mechanism, and 3 is a refrigerant pipe.
When the reheat dry operation is performed in this configuration, the refrigerant delivered from the compressor is, as shown by the arrow in the figure, the second indoor heat exchange unit 1b, the throttle mechanism 2, and the first indoor heat exchange unit 1a. Flow in the order of
[0004]
In such a reheat dry operation, an electronic expansion valve (not shown) normally installed on the outdoor unit side is fully opened and no throttle is performed, and the first and second indoor heat exchange units 1a and 1b are divided into two. The throttle mechanism section 2 provided therebetween has the function of reducing the pressure of the liquid-phase refrigerant and converting the refrigerant into a gas-liquid two-phase flow. That is, the second indoor heat exchange unit 1b, which is located on the upstream side in the refrigerant flow direction with the throttle mechanism 2 interposed therebetween, serves as an indoor reheater, and functions as a condenser that radiates heat to the air together with an outdoor heat exchanger (not shown). The first indoor heat exchange unit 1a downstream of the mechanism section 2 serves as an indoor cooler, and functions as an evaporator for cooling air.
[0005]
Therefore, since the indoor air is cooled and dehumidified by the first indoor heat exchange unit 1a and the indoor air is heated by the second indoor heat exchange unit 1b, the conditioned air blown into the room from the air conditioning indoor unit is: The cooled and dehumidified air and the heated air are mixed to reduce the temperature drop. The throttle mechanism unit 2 functions as a throttle mechanism by opening a hole of an appropriate size in the valve body of the two-way solenoid valve, and by closing the hole at the time of the reheat dry operation, the cooling operation and the heating operation. Sometimes it is fully open.
[0006]
Among the conventional air conditioners capable of the reheat dry operation described above, there is a conventional air conditioner having a muffler in a throttle device provided in an indoor heat exchanger as a measure against sound insulation of an indoor unit for air conditioning. This throttle device uses an orifice as a throttle portion, and is provided with a porous permeable body separated from the orifice. (For example, see Patent Document 1)
[0007]
[Patent Document 1]
JP-A-2002-061879 (paragraph number 0013-0020, FIGS. 3 and 4)
[0008]
[Problems to be solved by the invention]
By the way, in the above-described expansion device, the flow path cross-sectional area greatly varies between the expansion pipe and the refrigerant pipe. For this reason, when the cross-sectional area of the flow path increases rapidly, such as at the outlet of the throttle mechanism, the gas-liquid two-phase refrigerant may expand rapidly and generate cavitation. That is, as shown in FIG. 10, while the flow velocity V of the refrigerant decreases at the outlet of the throttle mechanism, the bubble B rapidly grows and expands (expands) due to the rapid decrease in pressure. And generate vibration. Therefore, noise (refrigerant flow noise) due to this vibration is generated, which is not preferable for an air conditioning indoor unit which is installed indoors and provides a comfortable indoor environment, and a countermeasure is desired.
The present invention has been made in view of the above circumstances, and has as its object to provide an air-conditioning indoor unit that suppresses refrigerant flow noise in a throttle mechanism and an air conditioner including the same.
[0009]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
In the air conditioning indoor unit according to the first aspect, an indoor heat exchanger for cooling or heating by exchanging heat between indoor air and a refrigerant is divided into a plurality of indoor heat exchange units, and the plurality of indoor heat exchange units are used. In an air conditioning indoor unit in which a throttle mechanism is provided between units,
The throttle mechanism is characterized by comprising throttle means for reducing the cross-sectional area of the refrigerant channel, and a bubble growth suppressing member provided in contact with the refrigerant outlet of the throttle means. is there.
[0010]
According to the air conditioning indoor unit of the first aspect, the throttle mechanism unit includes the throttle means for reducing the cross-sectional area of the refrigerant flow path, and the bubble growth suppressing member provided in contact with the refrigerant outlet of the throttle means. Therefore, the gas-liquid two-phase flow refrigerant flowing out of the throttle means passes through the bubble growth suppressing member provided in contact with the refrigerant outlet to suppress bubble growth. In particular, since the bubble growth suppressing member is in contact with the outlet of the throttle means, it is possible to reliably prevent bubble growth near the outlet of the throttle means in which small bubbles flowing out of the throttle means expand rapidly due to a pressure drop. .
[0011]
In the air conditioning indoor unit according to claim 1, the throttle means is a capillary tube, and a bypass flow path having an on-off valve is provided in parallel with the capillary tube, and the bubble growth suppressing member removes bubbles at an outlet of the capillary tube. It is preferable to subdivide it, so that the reheating dry operation can be easily performed by using a capillary tube that has a high degree of freedom in setting the throttle and has a large damping effect by the damping material, and switches the on-off valve of the bypass flow path. And the rapid expansion and diffusion of bubbles formed by cavitation can be prevented.
[0012]
In the air conditioning indoor unit according to claim 1 or 2, it is preferable that a straight pipe portion is provided in a refrigerant pipe connected to a refrigerant outlet side of the capillary tube, whereby a refrigerant causing bubble growth is generated. A sudden change in the cross-sectional area of the flow path does not occur near the outlet of the throttle means.
[0013]
An air conditioner according to a fourth aspect is an air conditioner indoor unit according to any one of the first to third aspects, a compressor for compressing the refrigerant, and heat exchange between the refrigerant and outdoor air. An air conditioning outdoor unit having an outdoor heat exchanger, and connecting the air conditioning indoor unit and the air conditioning outdoor unit, and a refrigerant pipe for circulating a refrigerant between the air conditioning indoor unit and the air conditioning indoor unit. , Are provided.
[0014]
According to the air conditioner of the fourth aspect, the throttle mechanism of the indoor unit for air conditioning has a throttle means for reducing the cross-sectional area of the refrigerant flow path, and bubble growth suppression provided in contact with the refrigerant outlet of the throttle means. With the structure including the member, the gas-liquid two-phase flow refrigerant flowing out of the throttle means passes through the bubble growth suppressing member provided in contact with the refrigerant outlet to suppress the growth of bubbles. In particular, since the bubble growth suppressing member is in contact with the outlet of the throttle means, it is possible to reliably prevent bubble growth near the outlet of the throttle means in which small bubbles flowing out of the throttle means expand rapidly due to a pressure drop. .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an air conditioning indoor unit and an air conditioner including the same according to the present invention will be described with reference to the drawings.
FIG. 3 is a block diagram illustrating a configuration example of the air conditioner. The air conditioner 10 includes an outdoor unit 20 for air conditioning, an indoor unit 30 for air conditioning, and a refrigerant pipe 11 for connecting these and circulating a refrigerant.
[0016]
The outdoor unit for air conditioning 20 includes a compressor 21 for compressing the refrigerant, a four-way valve 22 for selectively switching the flow direction of the refrigerant, and an outdoor for causing heat exchange between the refrigerant and outdoor air. The heat exchanger 23 and the electronic expansion valve 24 provided as main throttle means of the refrigeration cycle are main components. Reference numeral 25 in the figure denotes a propeller fan for the outdoor heat exchanger 23 driven by the electric motor 25a.
[0017]
The indoor unit 30 for air conditioning includes an indoor heat exchanger 31 for exchanging heat between indoor air and a refrigerant, and an indoor air exchanger that draws indoor air from the suction grill and passes the indoor air to the indoor heat exchanger 31 to remove the heat-exchanged air. A tangential fan 32 is provided as blowing means for blowing air out of the air outlet and returning the room. The tangential fan 32 is driven by an electric motor 32a.
In this case, the indoor heat exchanger 31 is divided into a plurality of blocks. In the illustrated example, it is divided into two blocks, a first indoor heat exchange unit 31a and a second indoor heat exchange unit 31b, and the two units 31a, 31b are connected by the refrigerant pipe 11.
[0018]
The refrigerant pipe 11 connecting the first indoor heat exchange unit 31a and the second indoor heat exchange unit 31b is provided with a throttling mechanism 40 for flowing and using the refrigerant during the reheating dry operation.
Specifically, as shown in FIG. 1, the refrigerant circuit between the first indoor heat exchange unit 31a and the second indoor heat exchange unit 31b connects the refrigerant pipe 11 with the first refrigerant flow path 11a and the second refrigerant flow. It is formed so as to be branched in parallel to the path 11b, and the throttle mechanism 40 is provided in one of the refrigerant pipes connected in parallel, that is, the second refrigerant flow path 11b.
[0019]
The throttle mechanism 40 has one end connected to the second refrigerant flow path 11b, and is provided in contact with a capillary tube 41 functioning as a throttle means and a refrigerant outlet (other end) side opening of the capillary tube 41. And a bubble growth suppressing member 42 provided. Since the refrigerant during the reheat dry operation flows from the second indoor heat exchange unit 31b to the first indoor heat exchange unit 31a as indicated by the arrow in FIG. 1, the refrigerant outlet side in this case is the first indoor heat exchange unit. This is the unit 31a side.
The first refrigerant flow path 11a connected in parallel with the second refrigerant flow path 11b is provided with an electromagnetic valve 43 functioning as an on-off valve. The solenoid valve 43 is for selectively switching between flowing the refrigerant to the above-described throttle mechanism section 40 and flowing the refrigerant while bypassing the throttle mechanism section 40. That is, by opening the electromagnetic valve 43, the one refrigerant channel 11 a functions as a bypass channel of the throttle mechanism 40, and by closing the electromagnetic valve 43, the refrigerant circulates through the throttle mechanism 40.
[0020]
Here, the configuration of the above-described aperture mechanism unit 40 will be described in detail with reference to FIG.
In the configuration example shown in FIG. 2, the bubble growth suppressing member 42 is provided in a fitting between the capillary tube 41 and the refrigerant pipe serving as the second refrigerant flow path 11 b, and the tip 41 a of the capillary tube 41 is connected to the bubble growing member 42. To make sure it is in contact with the surface. The connection fitting shown in the drawing is, for example, fitted by fitting a female fitting 44 made of brass and a male fitting 45 and caulking. The bubble growing member 42 is installed in the female fitting 44 concave portion 44 a, and the upstream of the bubble growing member 42. The distal end portion 41a of the capillary tube 41 is brought into close contact with the surface on the side.
[0021]
As will be described in detail later, the bubble growth suppressing member 42 has a function of suppressing the growth of bubbles formed by the cavitation phenomenon at the outlet side opening of the capillary tube 41, and the bubbles formed and growing in the refrigerant flow. Is divided into fine bubbles to form fine bubbles, and also acts as a flow resistance at the opening on the outlet side of the capillary tube 41 to reduce the flow velocity of the refrigerant flow. As the bubble growth suppressing member 42, a member forming a large number of meshes, for example, a metal mesh (wire mesh), a foamed metal, or the like can be used. As the metal mesh, it is preferable to select a metal mesh that is hardly mixed with foreign matters due to corrosion or the like. Specifically, it is preferable that the mesh is made of stainless steel (SUS).
In addition, as for the size of the mesh, if it is too small, foreign substances are likely to be clogged, and if it is too large, the original function of suppressing bubble growth cannot be sufficiently performed. preferable.
[0022]
Hereinafter, the operation of the air conditioner 10 having the above-described configuration will be described with reference to FIG.
The arrows in FIG. 3 indicate the flow direction of the refrigerant during the cooling / dehumidifying operation and the reheating dry operation, but the following description will focus on the reheat dry operation.
[0023]
The compressor 21 compresses and sends out the gas-phase refrigerant. This refrigerant is a high-pressure gas phase, and is supplied to the outdoor heat exchanger 23 by setting the four-way valve 22. The high-pressure gas-phase refrigerant introduced into the outdoor heat exchanger 23 exchanges heat with outdoor air passing outside the heat exchanger and condenses. That is, the outdoor heat exchanger 23 in this case functions as a condenser, and radiates heat from the refrigerant to the air.
[0024]
The refrigerant that has passed through the outdoor heat exchanger 23 is guided to the electronic expansion valve 24 through the refrigerant pipe 11. The electronic expansion valve 24 functions as a throttling unit during the cooling / dehumidifying operation and the heating operation, and does not perform throttling at the maximum opening degree (fully open) during the reheating dry operation. As a result, since the indoor heat exchanger 23 and the second indoor heat exchange unit 31b function as a condenser integrally connected via the refrigerant pipe 11, the second indoor heat exchange unit 31b radiates heat to indoor air. Then, it becomes an indoor reheater for heating.
[0025]
In this way, the refrigerant that has radiated heat to the air in the outdoor heat exchanger 23 and the second indoor heat exchange unit 31b and condensed becomes a high-temperature and high-pressure liquid phase flow, and is guided to the throttle mechanism section 40 through the refrigerant pipe 11. The throttle mechanism section 40 during the reheat dry operation fully closes the electromagnetic valve 43 to guide the refrigerant to the capillary tube 41 of the throttle means. The refrigerant that has passed through the capillary tube 41 is decompressed, becomes a low-temperature low-pressure liquid refrigerant (gas-liquid two-phase flow), and is guided to the first indoor heat exchange unit 31a.
In the first indoor heat exchange unit 31a, low-temperature and low-pressure liquid refrigerant and indoor air exchange heat. In this case, the first indoor heat exchange unit 31a functions as an evaporator, and functions as an indoor cooler that cools the refrigerant by removing heat of vaporization from air. As a result, the refrigerant in the gas-liquid two-phase flow is vaporized into a low-pressure gaseous phase, guided to the refrigerant pipe 11 and the four-way valve 22, and returned to the compressor 21.
[0026]
In this way, the refrigerant pipe 11 passes through the compressor 21, the four-way valve 22, the outdoor heat exchanger 23, the second indoor heat exchanger 31b, the throttle mechanism 40, the first indoor heat exchanger 31a, and the four-way valve 22 in this order. Thus, a refrigeration cycle is formed in which the refrigerant circulates clockwise and returns to the compressor 21 again. Then, by the circulation of the refrigerant, in the air conditioning indoor unit 31, the first indoor heat exchange unit 31a functions as an indoor cooler to cool and dehumidify the introduced indoor air, and at the same time, to the second indoor heat exchange unit 31a. The exchange unit 31b functions as an indoor reheater to heat the introduced indoor air. For this reason, the air-conditioned air blown into the room from the air-conditioning indoor unit 31 is obtained by mixing the cooled / dehumidified air and the heated air, thereby reducing the temperature drop compared to the normal dehumidification operation. Become.
[0027]
Further, in the cooling operation and the normal dehumidifying operation, the refrigerant circulates along the same route as that in the above-described reheating dry operation, and the gas-liquid state changes are repeated. However, in the air conditioning indoor unit 31, the main flow of the refrigerant flows through the first refrigerant flow path 11a because the electromagnetic valve 43 of the throttle mechanism 40 is opened and the pressure loss is greatly different. That is, the first indoor heat exchange unit 31a and the second indoor heat exchange unit 31b both function as an integral evaporator, and cool and dehumidify the introduced indoor air and blow it out into the room. In this case, an electronic expansion valve 24 that is installed on the air conditioning outdoor unit 20 side and whose opening is adjusted is used as the throttle unit in this case.
[0028]
In the heating operation, the refrigerant is circulated counterclockwise in the opposite direction to the above-described cooling and dehumidifying operation. That is, by operating the four-way valve 22 to guide the refrigerant delivered from the compressor 21 to the indoor heat exchanger 31 side, the indoor heat exchanger 31 functions as a radiator for condensing the refrigerant and heating the indoor air. The outdoor heat exchanger 23 functions as an evaporator that evaporates the refrigerant and cools the outside air. Also in this case, the electromagnetic valve 43 is opened, and the electronic expansion valve 24 is used as the throttle means.
[0029]
Next, the operation of the bubble growth suppressing member 42 will be described. The bubble growth suppressing member 42 is configured such that minute bubbles contained in the liquid-phase refrigerant flowing in the capillary tube 41 flow out from the distal end portion 41a to the refrigerant flow channel 11b side, and the flow channel cross-sectional area increases rapidly. Thus, rapid growth (expansion) due to a decrease in pressure with a decrease in flow velocity is prevented or suppressed. That is, the air bubbles flowing out from the tip portion 41a immediately pass through the air bubble growth suppressing member 42 such as a metal mesh provided in reliable contact. For this reason, even if the air bubbles expand due to a decrease in pressure and become large, when passing through a small mesh of about 100 mesh, the air bubbles are cut into small pieces.
If there is a gap between the tip 41a and the surface of the bubble growth suppressing member 42, that is, if the tip 42a is not in contact, the growth of bubbles is promoted, which is not preferable.
[0030]
FIG. 4 is a graph showing experimental results confirming the effects of the present invention. More specifically, as one embodiment of the present invention, a capillary tube 41 having a bubble suppression member 42 is used as the squeezing means (capillary formation and mesh insertion), and as a comparative example, a capillary tube having no bubble growth suppression member is used. It is the result of a comparative experiment between the case of using (capillary only) and the case of using the above-described conventional two-way solenoid valve (see FIG. 9).
The line graph shown in FIG. 4 shows the relationship between the 1/3 octave band center frequency (Hz) and the sound pressure level (dB) for the three cases of the present invention, the comparative example, and the conventional example. The solid line is the result of the present invention, the broken line is the result of the comparative example, and the dashed line is the result of the conventional example.
[0031]
According to this experimental result, by adopting the configuration of the present embodiment, a decrease in sound pressure level is realized in a wide frequency band, and a decrease in sound pressure level is particularly observed as the frequency increases. Specifically, in the frequency band of about 200 Hz or more, the dashed line of the comparative example shows a similar sound pressure change tendency to the one-dot chain line of the conventional example, but the sound pressure indicated by the solid line of the present embodiment. It can be seen that the level is relatively low.
[0032]
This is because the bubble growth suppressing member 42 is inserted into the capillary tube 41 in contact with the distal end portion 41a (mesh contact insertion), so that the gas-liquid two-phase refrigerant flow passing through the capillary tube 41 is reduced. Even when bubbles are formed due to cavitation due to space expansion at the outlet of the nozzle, even when bubbles are formed by cavitation, the mesh in contact suppresses the growth of bubbles in this refrigerant flow by bubble fragmentation. This means that the shock propagation to the inner wall of the refrigerant pipe due to the pulsation phenomenon caused by the presence of the bubbles has been alleviated, which means that the refrigerant flow noise caused by the shock propagation has been reduced.
In the case where the diaphragm means shown by a broken line is made into a capillary, the frequency band in which the sound pressure level is lower than that of the conventional product shown by the one-dot chain line is slightly increased. It is considered that this is because, when the countermeasure using the same amount of damping material is taken, the damping effect of the capillary is large. Therefore, it can be said that the configuration employing the capillary structure 41 and using the bubble growth suppressing member 42 as in the present embodiment most preferably achieves the reduction of the refrigerant flow noise.
[0033]
Next, a description will be given of a configuration of a connection portion between the throttle mechanism 40 provided with the bubble growth suppressing member 42 and the refrigerant pipe 11.
FIG. 5 is a graph showing experimental results confirming the operation and effect of the straight pipe portion L provided in the refrigerant outlet side of the capillary tube 41, that is, the refrigerant flow path 11b formed by the refrigerant pipe 11 connected to the tip end portion 41a. . More specifically, the case of adopting the configuration of the connecting portion using the refrigerant pipe 11b having the straight pipe portion shown by the solid line in FIG. 2 (capillary formation and mesh insertion), and the two-dot chain line in FIG. 7 shows a result of comparing sound pressure levels when the configuration of the connecting portion using the refrigerant pipe 11b having the outlet flow path enlarged portion 12 shown in FIG.
The line graph shown in FIG. 5 shows the ケ ー ス octave band center frequency (Hz) and the sound pressure level (dB) for the two cases of the present invention having a straight pipe portion and the comparative example having an outlet flow path enlarged portion. The solid line shows the result when the configuration having the straight pipe portion L of the present invention is adopted, and the broken line shows the result when the configuration having the outlet flow path enlarged portion 12 as a comparative example is adopted. Is shown.
[0034]
According to the experimental results, it is understood that the sound pressure level of the comparative example indicated by the broken line is high particularly in a large frequency band. This is because the refrigerant that has flowed out from the distal end portion 41 a of the capillary tube 41 through the bubble growth suppressing member 42 encounters a sudden change in the flow path cross-sectional area when passing through the outlet flow path enlarged portion 12, and thus cavitation. It is presumed that this is likely to occur and the refrigerant flow noise increases. Therefore, it is preferable to provide a straight pipe portion in the refrigerant pipe 11 connected to the capillary tube 41, and a preferable length L of the straight pipe section is 2D or more, where D is the diameter of the refrigerant pipe 11.
[0035]
Next, modified examples of the above-described bubble growth suppressing member 42 will be described with reference to FIGS.
The first modification shown in FIG. 6 shows a bubble growth suppressing member 42A in which a metal mesh is formed in a cage shape. The bubble growth suppressing member 42A is formed by caulking a metal ring 46 and fixed to the inner peripheral surface of the second refrigerant flow path 11b, and the tip 41a is in contact with the bubble growth suppressing member 42A.
[0036]
As shown in FIG. 6, the metal ring 46 as the bubble growth suppressing member 42 </ b> A is provided in the direction in which the distal end portion 41 a of the capillary tube 41 is inserted into the refrigerant pipe forming the refrigerant channel 11 b. The central portion of the mesh portion has a bulging shape, and the tip portion 41a of the capillary tube 41 comes into contact with the bulging portion.
According to this configuration, since the direction in which the capillary tube 41 is inserted and the direction in which the capillary tube 41 bulges during the formation of the refrigerant circuit, the tip portion 41a of the capillary tube 41 and the bubble growth suppressing member 42A can be reliably brought into pressure contact with each other.
[0037]
Even in such a configuration, as in the above-described embodiment, the minute bubbles in the refrigerant flowing in the capillary tube 41 pass through the bubble growth suppressing member 42A even if they flow out of the distal end portion 41a and try to expand. When it is subdivided. Therefore, the generation of refrigerant flow noise due to the generation of cavitation is suppressed.
[0038]
The second modification shown in FIG. 7 shows a bubble growth suppressing member 42B in which a metal mesh is formed in a cage shape. The bubble growth suppressing member 42B is fixed to the outer peripheral surface of the capillary tube 41 by caulking a metal ring 47, and the tip 41a is in contact with the bubble growth suppressing member 42B.
[0039]
Even in such a configuration, as in the above-described embodiment, the minute bubbles in the refrigerant flowing in the capillary tube 41 pass through the bubble growth suppressing member 42B even if they flow out of the tip portion 41a and try to expand. When it is subdivided. Therefore, the generation of refrigerant flow noise due to the generation of cavitation is suppressed.
[0040]
In the third modified example shown in FIG. 8, a filling member 48 is disposed inside a bubble growth suppressing member 42A in which a metal mesh is formed in a cage shape. The filling member 48 is formed by, for example, forming a metal mesh, metal fiber, foamed metal, or the like in accordance with the internal space shape of the basket-shaped bubble growth suppressing member 42A. That is, the mesh-shaped filling member 48 fills the internal space of the bubble growth suppressing member 42A, and the distal end 41a of the capillary tube 41 is inserted into the filling member 48.
[0041]
With such a configuration, since the filler 48 itself has a function of subdividing the bubbles and suppressing the growth of the bubbles, a dimension (manufacturing) for surely bringing the tip portion 41a into contact with the bubble growth suppressing member 42A. ) No management is required, and the same function as contact can be obtained simply by inserting the tip into the filler 48. That is, since the object of the bubble growth suppressing member that does not promote the expansion of the bubble can be achieved, the manufacturing process can be simplified.
[0042]
In addition, such a filler 48 can be combined with the bubble growth suppressing member 42B shown in FIG. 7, and the filler is packed into the distal end portion 41a of the capillary tube 41 by appropriate means. It is good also as a structure which holds.
Further, in the above-described embodiment and its modified example, the capillary tube 41 is adopted as the throttle means. However, the present invention is not limited to this, and a combination with other throttle means such as an orifice is also possible.
[0043]
The configuration of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.
[0044]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the indoor unit for air conditioning of this invention, the throttle mechanism comprised with the throttle means which reduces the cross-sectional area of a refrigerant flow path, and the bubble growth suppression member provided in contact with the refrigerant outlet of this throttle means. Therefore, when the gas-liquid two-phase flow refrigerant flowing out of the throttle means passes through the bubble growth suppressing member provided in contact with the refrigerant outlet, the expanding bubbles are fragmented and the growth of the bubbles is suppressed. You. For this reason, the refrigerant flow noise generated by the occurrence of cavitation is reduced, and the operating noise generated from the indoor air conditioning unit during the reheating dry operation is reduced, so that a comfortable indoor environment can be provided. In addition, an air conditioner including such an air-conditioning indoor unit has reduced operating noise and is highly productive.
[0045]
Further, if the restricting mechanism portion is provided with a restricting means for the capillary tube, and a bypass flow path having an on-off valve in parallel with the capillary tube, and the bubble growth suppressing member is configured to subdivide bubbles at the capillary tube outlet, The diaphragm means is inexpensive and has a high degree of freedom in setting the diaphragm, and a large vibration damping effect can be obtained by effectively utilizing the vibration damping material. By switching the on-off valve provided in the bypass flow passage, it is possible to easily select and switch from the cooling / dehumidifying operation and the heating operation to the reheating dry operation.
In particular, if a straight pipe portion is provided in the refrigerant pipe connected to the refrigerant outlet side of the capillary tube, a sudden change in the cross-sectional area of the refrigerant flow path causing bubble growth does not occur near the outlet of the throttle means, Eliminates the cause of loud refrigerant flow noise and enables quiet operation.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a throttle mechanism section relating to an indoor unit for air conditioning of the present invention.
FIG. 2 is a sectional view of an essential part showing a configuration example of a diaphragm mechanism shown in FIG. 1;
FIG. 3 is a block diagram showing an embodiment of the air conditioner according to the present invention.
FIG. 4 is a graph of an experimental result confirming the operation and effect of the aperture mechanism according to the present invention, wherein the horizontal axis represents a 1/3 octave band center frequency (Hz) and the vertical axis represents a sound pressure level (dB).
FIG. 5 is a graph of an experimental result confirming an operation effect of a straight pipe portion of a throttle mechanism according to the present invention, wherein the horizontal axis is a 1/3 octave band center frequency (Hz), and the vertical axis is a sound pressure level (dB). It is.
FIG. 6 is a sectional view showing a first modification of the aperture mechanism shown in FIG. 2;
FIG. 7 is a sectional view showing a second modification of the aperture mechanism shown in FIG. 2;
FIG. 8 is a sectional view showing a third modification of the aperture mechanism shown in FIG. 2;
FIG. 9 is a configuration diagram showing a conventional example of a throttle mechanism in an indoor unit for air conditioning.
FIG. 10 is an explanatory diagram regarding generation of refrigerant flow noise in a throttle mechanism.
[Explanation of symbols]
10 air conditioner
11 Refrigerant piping
11a 1st refrigerant flow path
11b Second refrigerant flow path
12 Enlarged outlet channel
20 Outdoor unit for air conditioning
21 Compressor
22 Four-way valve
23 outdoor heat exchanger
24 Electronic expansion valve (main throttle means)
25 propeller fan
30 Indoor units for air conditioning
31 indoor heat exchanger
31a 1st indoor heat exchange unit
31b Second indoor heat exchange unit
32 Tangential fan (blowing means)
40 Aperture mechanism
41 Capillary tube (throttle means)
41a Tip
42 Bubble growth suppression member
43 Solenoid valve (open / close valve)

Claims (4)

An indoor heat exchanger for cooling or heating by exchanging heat between indoor air and a refrigerant is divided into a plurality of indoor heat exchange units, and a throttle mechanism is provided between the plurality of indoor heat exchange units for air conditioning. In the indoor unit,
The air-conditioning system for air-conditioning, wherein the throttle mechanism is provided with throttle means for reducing a cross-sectional area of the refrigerant flow path, and a bubble growth suppressing member provided in contact with a refrigerant outlet of the throttle means. Indoor unit. 2. A capillary tube as said restricting means, a bypass flow path having an on-off valve provided in parallel with said capillary tube, and said bubble growth suppressing member subdivides bubbles at an outlet of said capillary tube. Indoor unit for air conditioning. The indoor unit for air conditioning according to claim 1 or 2, wherein a straight pipe portion is provided in a refrigerant pipe connected to a refrigerant outlet side of the capillary tube. An outdoor unit for air conditioning comprising the indoor unit for air conditioning according to any one of claims 1 to 3, a compressor for compressing the refrigerant, and an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air. And a refrigerant pipe for connecting the unit to the air conditioning indoor unit and the air conditioning outdoor unit, and circulating a refrigerant between the air conditioning indoor unit and the air conditioning indoor unit. Air conditioner.

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