JP2008267689A - Refrigerant distributor - Google Patents

Abstract

The present invention relates to a refrigerant distributor of a heat exchanger for an air conditioner that is applied to, for example, a room air conditioner for home use, and in particular, to perform stable distribution over a wide operating range for a heat exchanger that operates efficiently. A refrigerant distributor is provided. Moreover, the air conditioner which reduces malfunctions, such as dew to an indoor unit by deterioration of a distribution ratio, and a refrigerant | coolant flow noise is provided.
A refrigerant distributor provided with an inlet pipe, a plurality of outlet pipes 43 branched from the inlet pipe, and a plurality of grooves 44 on the inner surface of the inlet pipe, This is achieved by a refrigerant distributor provided with a double circular pipe portion having an inner pipe 45 having an outer diameter smaller than the minimum inner diameter of the inlet pipe between the inlets of the plurality of outlet pipes 43.
[Selection] Figure 4

Description

  The present invention relates to a refrigerant distributor of a heat exchanger for an air conditioner that is applied to, for example, a home room air conditioner, and more particularly to an apparatus that efficiently operates the heat exchanger.

  FIG. 1 is a diagram showing a configuration of a refrigeration cycle of a general household air conditioner. In the figure, 1 is a compressor, 2 is a four-way valve, 3 is a throttle device such as an electric valve, 4 is an indoor heat exchanger, and 5 is an outdoor heat exchanger.

  In the home air conditioner, by switching the four-way valve 2, the cooling operation (solid arrow) using the indoor heat exchanger 4 as an evaporator and the outdoor heat exchanger 5 as a condenser, and the indoor heat exchanger 4 as a condenser, A heating operation (broken arrows) using the outdoor heat exchanger 5 as an evaporator can be performed.

  For example, in the cooling operation, the high-temperature and high-pressure refrigerant compressed by the compressor 1 passes through the four-way valve 2 and flows into the outdoor heat exchanger 5, and dissipates heat and condenses by heat exchange with air. And after carrying out an isoenthalpy expansion | swell by the expansion | swelling apparatus 3, such as a motor operated valve, it flows into the indoor heat exchanger 4 as a gas-liquid two-phase flow in which gas and liquid are mixed at low temperature and low pressure. In the indoor heat exchanger 4, the refrigerant evaporates while increasing the dryness χ from the inlet to the outlet by an endothermic action from the air. And the refrigerant | coolant which came out of the indoor heat exchanger 4 returns to the compressor 1, and comprises a cycle. Incidentally, the dryness χ is a value obtained by dividing the refrigerant gas mass flow rate by the refrigerant total mass flow rate, that is, dryness χ≡refrigerant gas mass flow rate / refrigerant total mass flow rate.

  Here, in the indoor heat exchanger 4 that acts as an evaporator, the loss due to the flow resistance in the piping constituting the heat exchanger greatly affects the performance degradation as the evaporator. In order to suppress this loss, the indoor heat exchanger 4 is generally configured to branch in parallel through a plurality of paths and to flow the refrigerant (two paths 11 and 12 in FIG. 1). A refrigerant distributor 31 that distributes the gas-liquid two-phase flow refrigerant to the plurality of paths is required. A refrigerant that is a gas-liquid two-phase flow has a density ratio of several tens of times between the liquid refrigerant and the gas refrigerant, so that the flow velocity is greatly different, the gas-liquid interface is disturbed, and the refrigerant flow becomes unstable.

  Also, for example, when the refrigerant flow rate varies widely from a small flow rate to a large flow rate, such as an inverter-driven room air conditioner with variable compressor rotation speed, or when the processing accuracy of the refrigerant distributor 31 varies. It can be said that the distribution of the liquid refrigerant flowing into the refrigerant distributor 31 in the pipe cross section is greatly different or greatly varied. Further, the centrifugal force due to the bending (curved portion) of the connecting pipe upstream of the distributor and the action of gravity due to the inclination of the inlet pipe also affect this variation.

  For this reason, a path in which the liquid refrigerant contributing to evaporation in the heat exchanger sufficiently flows and a path in which the liquid refrigerant flows only insufficiently and is depleted are generated. When the liquid refrigerant is depleted in the middle of the pass, the heat exchangers after that part can hardly perform heat exchange and cannot exhibit sufficient performance. In other words, the refrigerant cannot be fully utilized, and it is necessary to obtain the necessary capacity by increasing the refrigerant flow rate, that is, by increasing the refrigerant flow rate by rotating the compressor at a high speed. In this case, wasteful work to be input to the compressor increases, so that power saving cannot be achieved. Furthermore, when the air that has been sufficiently cooled in the path through which the liquid refrigerant sufficiently flows and the latent heat is removed, and the air that is hardly cooled and remains in the path in which the liquid refrigerant has been depleted merges downstream of the heat exchanger, Condensation occurs in the air passage, and water drops mix with the air that blows out. Such exposure of the indoor unit causes discomfort for the user, such as dust adhesion and eventually mold generation.

  Moreover, when the reheat dehumidification system etc. which did not lower the blowing temperature of an indoor unit are employ | adopted, the structure of a refrigerating cycle will become like FIG. That is, the expansion device 33 is provided between the refrigerant paths of the indoor heat exchanger 4, and the refrigerant is decompressed by the expansion device, whereby the refrigerant paths 21 and 22 are the condenser, and the refrigerant paths 11 and 12 are the evaporator. This method is realized by mixing each outlet temperature.

  In the configuration of FIG. 2, since the number of passes decreases before entering the expansion device 33, it is necessary to redistribute the refrigerant flowing out from the expansion device 33 to the refrigerant paths 11 and 12 by the refrigerant distributor 32. During the cooling operation, the refrigerant flowing into the refrigerant distributor 32 has a higher refrigerant inlet dryness than the refrigerant flowing into the refrigerant distributor 31. This is because heat is exchanged to some extent in the refrigerant paths 21 and 22. This can be understood by considering the bottom part of the trapezoidal part of the Mollier diagram. For this reason, the refrigerant distributor 32 must distribute a very small amount of liquid refrigerant. Distribution of liquid refrigerant at such a high dryness is a difficult problem because it is more susceptible to the shape of the inlet tube and gravity than the distribution at low dryness.

  Various countermeasures have been considered for such problems relating to refrigerant distribution.

  For example, when a refrigerant distributor is installed at the inlet of the indoor heat exchanger 4 that acts as an evaporator during cooling operation, the refrigerant inlet dryness χ is relatively small in a general household air conditioner, and is about 0.2. . In such a case, as disclosed in Patent Document 1, there is a technique in which the refrigerant flow is swirled and a centrifugal force larger than gravity is applied to reduce the influence of gravity and improve refrigerant distribution.

  However, even if the liquid refrigerant is swirled, if the refrigerant flow rate is small, the flow rate is slow, a large swirl cannot be given, and the necessary centrifugal force cannot be given. In addition, when a refrigerant distributor is installed in the middle of the heat exchanger piping, such as when the reheat dehumidification method is used, the refrigerant is very dry and the amount of liquid refrigerant used for swirling is very small. Cannot generate power.

  For this reason, there is a technique such as Patent Document 2 in which surface tension is applied by a fine groove to reduce the influence of gravity and improve refrigerant distribution.

JP 2000-105026 A JP 2003-014337 A

  It is possible to reduce the gravity effect due to the inclination of the inlet pipe to some extent by giving a swirl to the refrigerant flow and applying a centrifugal force, but the centrifugal force at the bending (curved part) of the connecting pipe upstream of the inlet pipe It is difficult to reduce the unevenness of the liquid refrigerant due to. In addition, since the liquid refrigerant is biased differently depending on the flow rate, the distribution ratio cannot be maintained over a wide flow range.

  Then, an object of this invention is to provide the refrigerant | coolant divider | distributor which can perform the stable distribution in a wide operating range. It is another object of the present invention to provide an air conditioner that reduces problems such as dew condensation on indoor units due to deterioration of the distribution ratio and refrigerant flow noise.

The purpose of the present invention is to
An inlet pipe,
A plurality of outlet pipes branched from the inlet pipe;
In the refrigerant distributor provided with a plurality of grooves on the inner surface of the inlet pipe,
This is achieved by a refrigerant distributor provided with a double circular pipe portion having an inner pipe having an outer diameter smaller than the minimum inner diameter of the inlet pipe between the middle of the inlet pipe and the inlet of the plurality of outlet pipes.

The object of the present invention is to
During the dehumidifying operation, the refrigerant flows in the order of the compressor, the outdoor heat exchanger, the first expansion device, the first indoor heat exchanger, the second expansion device, and the second indoor heat exchanger, and returns to the compressor. In
At the entrance of the second indoor heat exchanger,
An inlet pipe, a plurality of outlet pipes branched from the inlet pipe, and a refrigerant distributor provided with a plurality of grooves on the inner surface of the inlet pipe, from the middle of the inlet pipe to the inlets of the plurality of outlet pipes In the meantime, this is achieved by an air conditioner provided with a refrigerant distributor provided with a double circular pipe portion having an inner pipe having an outer diameter smaller than the minimum inner diameter of the inlet pipe.

  According to the present invention, stable distribution can be performed over a wide operating range. Moreover, malfunctions, such as dew condensation to the indoor unit of an air conditioner, can be suppressed. Moreover, the refrigerant | coolant flow noise in an air conditioner can be reduced.

  The best mode for carrying out the present invention will be described below.

The first embodiment will be described in detail. FIG. 3 shows a refrigerant distributor in the present embodiment. A connection pipe 41 into which a refrigerant flow 40 in a gas-liquid two-phase state flows, an inlet pipe 42 and a plurality of outlet pipes 43 are provided, and a plurality of fine spiral grooves 44 are provided on the inner surface of the inlet pipe 42. In addition, a double circular pipe portion X is configured by providing an inner tube 45 having an outer diameter smaller than the minimum inner diameter of the inlet tube 42 at the outlet portion of the inlet tube 42. As the name implies, the double circular pipe portion X refers to a portion where the pipes are doubled, and the space inside the inner pipe 45 constituting a part of the double circular pipe portion X is X1, the inner pipe. A space between the outer side of 45 and the inner side of the inlet pipe 42 is defined as X2. 46 is a flange for fixing the inner tube 45, and 47 is a view of the flange cut along the AA 'section. FIG. 4 is a perspective view of FIG. 3, and a hole 46 passes through the flange 46 according to the position and inner diameter of the outlet pipe, and the inner pipe 45 is fixed to the center of the flange 46.

  When the gas-liquid two-phase refrigerant flow 40 flowing in from the inlet pipe 42 flows in the pipe, the liquid refrigerant is introduced into the groove due to the surface tension action at the fine spiral groove 44 provided on the inner surface of the inlet pipe 42. Be drawn. Here, since the liquid refrigerant is affected by the surface tension as the gap between the grooves is finer, the liquid refrigerant is preferably a fine groove. Further, the total sectional area in the circumferential direction of the groove portion shown by the oblique line in the drawing cut along the section BB 'in FIG. 3 must be larger than the volume flow rate of the liquid refrigerant per unit sectional area. This is because if the cross-sectional area of the groove is smaller than the volume flow rate of the liquid refrigerant, the liquid refrigerant overflows from the groove and the effect of the groove is reduced. That is, it is preferable that the all-liquid refrigerant flows while fitting in the groove.

  In the refrigerant flow 40, the liquid refrigerant is drawn into the groove on the inner wall of the inlet pipe 42, so that the central portion of the inlet pipe 42 is an area where the gas refrigerant mainly flows. The liquid refrigerant flows in the groove 44 in the direction of the outlet of the inlet pipe 42 by the shearing force with the gas refrigerant as a driving force. That is, the liquid refrigerant adhering to the inner wall is pulled by the gas refrigerant and flows toward the outlet.

  The refrigerant flow 40 that reaches the outlet portion of the inlet pipe 42 flows through the double circular pipe portion X having the inner pipe 45. At this time, the gas refrigerant in the central portion of the refrigerant flow 40 flows into the inner side X1 of the inner tube 45, the liquid refrigerant flows into the space X2 sandwiched between the groove 44 and the outer periphery of the inner tube 45, and the gas refrigerant And liquid are almost separated. This is because the liquid refrigerant is held in the groove 44 by the surface tension even when the liquid refrigerant is biased due to the centrifugal force at the bending (curved portion) of the connecting pipe 41 as shown in FIG. Because. Therefore, this surface tension reduces the influence of the inclination of the inlet pipe 42 in the direction of gravity.

Considering before and after separation of the gas refrigerant and the liquid refrigerant, the gas refrigerant flows into the inside X1 of the inner tube 45, thereby reducing the cross-sectional area of the flow path and increasing the pressure loss. Further, the liquid refrigerant flows into the outer space X2 to reduce the driving force due to the shearing force with the gas refrigerant, and the external force applied to the liquid refrigerant mainly includes the frictional force of the groove wall surface and the outer periphery of the inner tube 45. Become.

  Even if there is a bias in the circumferential distribution of the liquid refrigerant on the upstream side of the double circular pipe portion X and the gas refrigerant is about to enter the space X2, the gas refrigerant in the space X2 Since the frictional force is received from the portion, the pressure loss is received rather than the flow in the space X1. For this reason, the gas refrigerant flows into the space X1 having a smaller pressure loss, and the space X2 is almost filled with the liquid refrigerant.

  However, when the pressure loss acting on the liquid refrigerant in the outer peripheral portion X2 of the inner tube 45 is larger than the pressure loss acting on the gas refrigerant inside the inner tube 45, the refrigerant is clogged in the space X2, and the liquid refrigerant is contained in the inner tube 45. There is a risk of overflowing from the gap X2 at the outer periphery. In this case, the overflowing liquid refrigerant flows into the inner pipe X1, and the liquid refrigerant and the gas refrigerant cannot be separated successfully.

  Conversely, when the pressure loss acting on the liquid refrigerant in the outer peripheral portion X2 of the inner tube 45 is smaller than the pressure loss acting on the gas refrigerant inside the inner tube 45, the gas refrigerant enters the space X2 portion, and the liquid refrigerant and the gas refrigerant Separation from and does not go well.

  Accordingly, the outer diameter of the inner pipe 45 is a diameter having a radius from the center of the inlet pipe to the apex of the groove in order to reliably guide the liquid refrigerant flowing in the spiral groove 44 to the gap X2 in the outer peripheral portion. Alternatively, the diameter may be smaller than that. However, if it is too small, the above-mentioned problem appears, so it may be up to about 10% smaller than the radius.

  Further, the length of the double circular pipe portion X is set such that the difference in pressure loss between the gas refrigerant flowing through the inside X1 and the liquid refrigerant flowing through the gap X2 between the outer peripheral portions becomes zero. That is, as shown in FIG. 11, the length of the double circular tube portion X is determined according to the hydraulic pressure loss of the outer tube.

  In this regard, in the conventional technique, the liquid refrigerant and the gas refrigerant rectified by the inlet pipe (42) flowing into the distributor are distributed as they are. After the refrigerant flow is rectified into an annular shape at the inlet pipe, the gas and liquid flowed directly into the enlarged flow path. It spreads uniformly to the outer peripheral side, and proper distribution of the refrigerant could be realized. However, when the flow rate is small, the swirl component does not occur in the groove portion, and it is unevenly distributed within the pipe cross section and reaches the outlet pipe (43) inlet, resulting in inappropriate distribution. In other words, the conventional one cannot appropriately cope with a wide flow range in which the refrigerant flow is operated from a small flow rate to a large flow rate.

  On the other hand, in the present embodiment, the liquid and the gas are separated and distributed, so that they can be distributed appropriately. The distribution ratio to each path is determined only by the distribution ratio of the liquid refrigerant, and the gas refrigerant is automatically distributed by the pressure loss of the flow path after the gas-liquid merge. When it is desired to change the distribution ratio, the size and number of holes, that is, the total area of each of the flow paths to be distributed may be changed as described later. Here, it is assumed that the holes 46a and 46b are the same. The refrigerant flow 40 that has passed through the double circular pipe portion X having the inner pipe 45 is equally distributed to the outlet pipe 43 from the holes 46 a and 46 b that penetrate the flange 46. Note that the equal distribution means that the liquid refrigerant having a high density, which is a dominant part in the weight ratio of all the refrigerants, is distributed almost equally. Further, the gas refrigerant hardly contributes to the distribution ratio.

  At the inlet of the outlet pipe 43, the gas refrigerant that has passed through X1 and the liquid refrigerant that has passed through X2 merge.

  Then, with reference to FIG. 6, the structure and operation | movement of the indoor heat exchanger of the domestic air conditioner in this embodiment are demonstrated. FIG. 6 is a configuration diagram of a refrigerant circuit of the indoor heat exchanger. The refrigerant distributor is provided in the middle of the refrigerant pipe.

In the indoor heat exchanger, in order to exchange heat between air and the refrigerant, the heat exchangers 200, 201, and 202 that are bent and disposed are disposed in the indoor unit casing 114. Heat exchanger 201,
Refrigerant distributors 31 and 32 are provided in 202, respectively. Reference numeral 112 denotes a dehumidifying valve for performing reheat dehumidification, and reference numeral 113 denotes a cross-flow fan that supplies an air volume for heat exchange.

  In each of the heat exchangers 200, 201, and 202, a plurality of fins are stacked in the direction perpendicular to the paper surface, and a plurality of heat transfer tubes pass through the fins. Further, the plurality of heat transfer tubes are connected by, for example, a U-shaped connection tube to form a refrigerant path.

  The refrigerant distributor 31 is a distributor that distributes one path to a plurality of paths, and the refrigerant path 310 is distributed to the plurality of refrigerant paths by the refrigerant distributor 31. In FIG. 6, the refrigerant paths 311 and 312 are distributed to two paths. The refrigerant paths 311 and 312 join after passing through the heat exchangers 200 and 201 to form one path, and are connected to the refrigerant path 320 provided with the dehumidifying valve 112 to form a continuous refrigerant circuit.

  Similarly to the refrigerant distributor 31, the refrigerant distributor 32 is a distributor that distributes one path to a plurality of paths, and distributes the refrigerant path 320 to the plurality of refrigerant paths. In FIG. 6, the refrigerant paths 321 and 322 are distributed to two paths. The refrigerant paths 321 and 322 merge after passing through the heat exchanger 202 to form one path, and are connected to the refrigerant path 323 to form a continuous refrigerant circuit. Then, the refrigerant path 323 is led to an outdoor unit (not shown), and is connected to a portion disclosed in FIG. 6 as a refrigerant path 310 through a compressor, an outdoor heat exchanger, and a decompression unit.

  Next, the operation of the indoor heat exchanger will be described. During the cooling operation, the refrigerant flows from an outdoor unit (not shown) into the refrigerant path 310 (in the direction of the solid arrow). The refrigerant that has flowed in is distributed to the two paths of the refrigerant paths 311 and 312 by the refrigerant distributor 31 and exchanges heat with air by the heat exchangers 200 and 201. Thereafter, the refrigerant passes through the refrigerant path 320 and passes through the dehumidifying valve 112 and flows into the refrigerant distributor 32. Then, the refrigerant is again distributed to the refrigerant paths 321 and 322, and exchanges heat with air by the heat exchanger 202.

When this embodiment is applied to the refrigerant distributor 32 shown in FIG. 2, the gas-liquid two-phase refrigerant having a high dryness (around χ = 0.7) passing through the refrigerant path 320 flows in the groove 44 of the inlet pipe 42 in an annular flow. Further, the gas is separated into gas and liquid by the double circular tube portion X (X1, X2) constituted by the inner tube 45. Then, it is equally distributed to the two paths 321 and 322, and heat is exchanged with air by the heat exchanger 202.

  At this time, since the liquid refrigerant and the gas refrigerant are separated mainly by using the surface tension in the space X2 on the groove 44 side and the inner side X1 of the inner pipe 45, the inclination of the inlet pipe 42 in the gravitational direction or the connection pipe It is possible to reduce the influence of the centrifugal force at the bend (curved portion).

  Although it repeats, in this embodiment, since a liquid and gas are isolate | separated and distributed, it can distribute appropriately. Therefore, it is possible to perform refrigerant distribution at an optimum distribution ratio not only when the refrigerant flow rate at the maximum capacity or the rated capacity is large but also when the refrigerant flow rate is low at the intermediate capacity or the minimum capacity. As a result, it is not necessary to operate the compressor more than necessary, and the electric input can be reduced. In addition, problems such as exposure to indoor units due to deterioration of the distribution ratio are eliminated. In addition, since the gas-liquid two-phase flow is separated and distributed into a single-phase flow for each of liquid and gas, the refrigerant flow noise is reduced. Therefore, it is preferable to provide the refrigerant distributor 32 at least at the inlet of the indoor heat exchanger downstream of the dehumidifying valve 112. Of course, it may be provided at the inlet of the indoor heat exchanger upstream of the dehumidifying valve 112.

  In the present embodiment, the operation of the distributor that divides one path into two paths has been described. However, the same effect can be obtained even when the outlet pipe has three paths and four paths. Incidentally, the flange 46 is an onigiri type in the case of 3 passes and a square type in the case of 4 passes. Of course, the flange 46 may be circular in these cases.

  Moreover, although the case where the refrigerant distributor was applied in the middle of the refrigerant pipe of the indoor heat exchanger was described in the present embodiment, the present invention can also be applied to a case where reheat dehumidification is not performed, for example. At this time, since the dehumidification valve becomes unnecessary, even when the dryness of the refrigerant at the inlet is low (when the wetness is high), as in the case of all two passes from the inlet to the outlet of the indoor heat exchanger, The same effect can be obtained by optimizing the shape and inner diameter of the groove 44 of the inlet pipe 42 and the outer diameter and thickness of the inner pipe 45 in accordance with the inlet refrigerant state.

The second embodiment will be described in detail. FIG. 7 shows a refrigerant distributor in the present embodiment. A connection pipe 41 into which a refrigerant flow 40 in a gas-liquid two-phase state flows, an inlet pipe 42 and a plurality of outlet pipes 43 are provided, and a plurality of fine spiral grooves 44 are provided on the inner surface of the inlet pipe 42. Further, by providing an inner tube 45 having an outer diameter smaller than the minimum inner diameter of the inlet tube 42 at the outlet portion of the inlet tube 42, a double circular tube portion X (X1, X2) is configured.

  The configuration so far is the same as that of the first embodiment.

51 is a liquid refrigerant storage part in which the liquid refrigerant separated by the double circular pipe part is stored. Also,
46 is a flange for fixing the inner tube 45, and 47 is a view of the flange cut along the AA 'section. A hole that matches the position and inner diameter of the outlet pipe passes through the flange 46, and the inner pipe 45 is fixed to the center of the flange 46.

  The effect of gas-liquid separation by the double circular tube portion having the groove 44 and the inner tube 45 and the effect when incorporated in the heat exchanger are the same as those in the first embodiment.

The refrigerant stream 40 flows through a double circular tube portion X having an inner tube 45. At this time, the gas refrigerant in the central portion of the refrigerant flow 40 is separated into the interior X1 of the inner tube 45, and the liquid refrigerant in the outer peripheral portion is separated into the space X2 sandwiched between the groove 44 and the outer periphery of the inner tube 45. After passing through the double circular pipe part, the liquid refrigerant is temporarily stored in the liquid refrigerant storage part 51. Liquid refrigerant reservoir 51

  Here, the volume of the liquid refrigerant storage unit 51 is the refrigerant between the double circular pipe portion X and the outlet pipe at the maximum refrigerant flow rate when operating with an overload, such as when the cooling dash operation or the outside air temperature is high. Is determined to be smaller than the inside X1 of the inner tube 45. This prevents the liquid refrigerant from overflowing into the inner pipe because the flow path pressure loss of the liquid refrigerant is smaller than the pressure loss of the inner pipe in a wide flow rate range.

  As a result, the liquid refrigerant can be stably supplied to the outlet pipe even when the flow rate varies. For example, even if a gas refrigerant is mixed into the liquid refrigerant in the outer peripheral portion due to fluctuations in the flow rate, the liquid refrigerant storage unit 51 performs gas-liquid separation. Distribution is made to the path. Therefore, in addition to the merit of the first embodiment, stable distribution can be performed in a wider operation range from a small flow rate to a large flow rate.

The third embodiment will be described in detail. FIG. 8 shows a refrigerant distributor in the present embodiment. A connection pipe 41 into which a refrigerant flow 40 in a gas-liquid two-phase state flows, an inlet pipe 42 and a plurality of outlet pipes 43 are provided, and a plurality of fine spiral grooves 44 are provided on the inner surface of the inlet pipe 42. Further, by providing an inner tube 45 having an outer diameter smaller than the minimum inner diameter of the inlet tube 42 at the outlet portion of the inlet tube 42, a double circular tube portion X (X1, X2) is configured. The configuration so far is the same as that of the first embodiment.

  66 is a flange with an orifice for fixing the inner pipe 45 and adjusting the flow rate of the liquid refrigerant, and 67 is a flange cross-sectional view of the flange cut along the AA ′ cross section. The orifice-equipped flange 66 has a hole penetrating at a position where the outlet pipe is connected and having a cross-sectional area corresponding to each required flow rate. The shape of the hole may be a plurality of round holes having the same diameter as 69 in addition to a sector shape such as 68. An inner tube 45 is fixed to the center of the flange 66 with the orifice.

  The effect of gas-liquid separation by the double circular tube portion X having the groove 44 and the inner tube 45 and the effect when incorporated in the heat exchanger are the same as those in the first embodiment.

On the other hand, it may not always be optimal to distribute evenly to the plurality of outlet pipes by the refrigerant distributor. This is due to the uneven distribution of liquid refrigerant due to the positional relationship between the refrigerant fan 113 and the heat exchanger 202 in the indoor unit shown in FIG. 6 and the deviation of the wind speed distribution of the casing surrounding the heat exchangers 200, 201, 202. This is because it may be advantageous to generate the above. For example, the wind flow rate passing through the heat exchanger 202 is larger in W1 passing through the upper part than the wind flow rate W2 passing through the lower part due to the shape of the housing. Therefore, by flowing more liquid refrigerant in the refrigerant path 321 than in the refrigerant path 322, the heat exchange in that part can be maximized, and the performance can be improved by optimally using all the heat exchangers. .

  In FIG. 8, the liquid refrigerant obtained by the gas-liquid separation of the refrigerant flow 40 passing through the double circular pipe portion can be distributed to the optimum liquid amount according to the cross-sectional area ratio of the orifices and supplied to the outlet pipe.

  Thus, the refrigerant can be fully utilized in each pass, and the user can comfortably use the room air conditioner without causing dew to the air passage and the cross-flow fan 113 that is the indoor fan in the indoor unit.

  9 and 10 show a refrigerant distributor showing another structure of the third embodiment. The difference from the refrigerant distributor is that the distribution ratio is adjusted by a bypass pipe. 76a and 76b in FIG. 9 and 86a and 86b in FIG. 10 are bypass pipes for sending the liquid refrigerant separated from the double circular pipe section to the outlet pipe.

  In the refrigerant distributor of FIG. 9, when adjusting the distribution ratio, a recess (necking) is provided in a part of the bypass pipe where it is desired to suppress the supply of liquid refrigerant. That is, it is a method of adjusting the pressure loss by the cross-sectional area. In the refrigerant distributor of FIG. 10, when adjusting the distribution ratio, there is also a method in which an annular path is provided as shown and the pressure loss is adjusted by the length of the bypass pipe to suppress the supply of liquid refrigerant. By doing so, it becomes possible to finely adjust the distribution ratio after installing the refrigerant distributor. However, if the resistance of the bypass pipe portion is large, the liquid refrigerant overflows without flowing and flows through the inner pipe 45, so it is necessary to adjust the thickness of the pipe.

  According to the above, the gas-liquid two-phase flow circulated by the inner surface groove of the inlet pipe causes the liquid refrigerant to flow in the outer peripheral side / groove part by the double circular pipe part, and the gas refrigerant flows in the inner peripheral side / center side. Therefore, not only in areas with high flow rate and low dryness where swirling by grooved pipes is dominant, but also in areas with low flow rate and high dryness where swirling does not occur due to grooved pipes, the connection pipe upstream of the inlet pipe It is possible to reduce the influence of liquid refrigerant bias and gravity due to the centrifugal force at the bend (curved portion).

The refrigeration cycle block diagram of a general household air conditioner. The block diagram of the refrigerating cycle at the time of employ | adopting a reheat dehumidification system. The refrigerant | coolant piping figure which applied this invention to the indoor heat exchanger of a domestic air conditioner. FIG. 4 is a perspective view of FIG. 3. The figure which shows the flow of a refrigerant | coolant. The block diagram (sectional drawing) of the refrigerant circuit of an indoor heat exchanger. The refrigerant distributor in another Example. The refrigerant distributor in another Example. The refrigerant distributor in another Example. The refrigerant distributor in another Example. Relationship between the double circular pipe part and outer pipe fluid pressure loss.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Throttling device 4 such as an electric valve Indoor heat exchanger 5 Outdoor heat exchangers 11, 12, 21, 22, 310 to 312, 320 to 323 Refrigerant paths 31 and 32 Refrigerant distributor 40 Refrigerant flow 41 Connection pipe 42 Inlet pipe 43 Outlet pipe 44 Groove 45 Inner pipe 46, 66... Flange 47 Flange sectional view 51 Liquid refrigerant reservoir 67. Flange sectional view 68, 69 Orifice hole 76a, 76b, 86a, 87b Liquid bypass pipe 112 Dehumidification valve 113 Cross-flow fan 114 Indoor unit housing 200 to 202 Heat exchanger

Claims (5)

An inlet pipe,
A plurality of outlet pipes branched from the inlet pipe;
In the refrigerant distributor provided with a plurality of grooves on the inner surface of the inlet pipe,
A refrigerant distributor provided with a double circular pipe portion having an inner pipe having an outer diameter smaller than the minimum inner diameter of the inlet pipe between the middle of the inlet pipe and the inlet of the plurality of outlet pipes. In claim 1,
A refrigerant distributor characterized in that a space is provided between the outlet of the double circular pipe portion and the plurality of outlet pipe inlets for storing the refrigerant flowing out from the path on the outer peripheral side of the double circular pipe portion. . In claim 1,
A plurality of tubes are disposed between the outlet of the double circular tube portion and the plurality of outlet tube inlets,
A refrigerant distributor, wherein a cross-sectional area of each pipe or a length of each pipe is changed so that a flow resistance of the refrigerant flowing in the pipe is adjusted. During the dehumidifying operation, the refrigerant flows in the order of the compressor, the outdoor heat exchanger, the first expansion device, the first indoor heat exchanger, the second expansion device, and the second indoor heat exchanger, and returns to the compressor. In
At the entrance of the second indoor heat exchanger,
An inlet pipe, a plurality of outlet pipes branched from the inlet pipe, and a refrigerant distributor provided with a plurality of grooves on the inner surface of the inlet pipe, from the middle of the inlet pipe to the inlets of the plurality of outlet pipes An air conditioner comprising a refrigerant distributor provided with a double circular pipe portion having an inner pipe having an outer diameter smaller than the minimum inner diameter of the inlet pipe. In claim 4,
An air conditioner characterized in that an inlet of the first indoor heat exchanger is provided with the same refrigerant distributor as the refrigerant distributor provided at the inlet of the second indoor heat exchanger.

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