JP2017083080A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger that restrains a decrease in heat exchange performance.SOLUTION: An indoor heat exchanger 400 comprises a first path 450, a second path 460, and a first flow divider 440. The first path 450 consists of only one or more first heat transfer pipes. The second path 460 includes one or more second heat transfer pipes. The first flow divider 440 divides an inflow refrigerant into the first path 450 and the second path 460. The pipe diameter of the second heat transfer pipes is larger than the pipe diameter of the first heat transfer pipes. The flow passage cross-sectional area of the second path 460 changes in the middle of the second path 460.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger.

  A heat exchanger having a plurality of capillary tubes branched from a shunt body is known (see Patent Document 1 (Japanese Patent Laid-Open No. 2011-163741)).

  In this type of heat exchanger, the heat exchange performance deteriorates due to the pressure loss in the capillary tube.

  The subject of this invention is providing the heat exchanger which suppresses the fall of heat exchange performance.

  The heat exchanger according to the first aspect of the present invention includes a first path, a second path, and a first shunt. The first path consists of only one or more first heat transfer tubes. The second path includes one or more second heat transfer tubes. The first flow divider diverts the flowing refrigerant into the first path and the second path. The tube diameter of the second heat transfer tube is larger than the tube diameter of the first heat transfer tube. The flow path cross-sectional area of the second pass changes in the middle of the second pass.

  Here, if the tube diameter of the second heat transfer tube included in the second path is larger than the tube diameter of the first heat transfer tube, the second path consists of only one or more second heat transfer tubes, and the second If the cross-sectional area of the two-pass flow path is constant from the entrance to the exit of the second pass, most of the refrigerant flows into the second pass. Therefore, in this case, the heat exchange performance of the first pass cannot be used effectively. On the other hand, when the pressure loss is adjusted by the capillary tube, the heat exchange performance deteriorates due to the pressure loss at the capillary tube.

  In the heat exchanger according to the first aspect of the present invention, the pressure loss is adjusted by changing the flow path cross-sectional area of the second pass in the middle of the second pass. In adjusting the pressure loss, since it is not necessary to provide a capillary tube, it is possible to suppress a decrease in heat exchange performance. In addition, since the pressure loss is adjusted by the second pass having the heat exchange performance, the heat exchange performance can be improved not only in suppressing the decrease in the heat exchange performance.

  In the heat exchanger according to the second aspect of the present invention, the second path includes three or more second heat transfer tubes and a second shunt. The second flow divider diverts the refrigerant that has entered from at least one second heat transfer tube to at least two second heat transfer tubes.

  In the heat exchanger according to the second aspect of the present invention, the pressure loss of the entire second path can be adjusted by interposing at least one second heat transfer tube in front of at least two second heat transfer tubes.

  In the heat exchanger according to the third aspect of the present invention, the second path includes one or more third heat transfer tubes. The third heat transfer tube is arranged on the upstream side of the second heat transfer tube. The tube diameter of the third heat transfer tube is smaller than the tube diameter of the second heat transfer tube.

  In the heat exchanger according to the third aspect of the present invention, the one or more third heat transfer tubes included in the second path are arranged upstream of the one or more second heat transfer tubes. Since the tube diameter of the third heat transfer tube is smaller than the tube diameter of the second heat transfer tube, the pressure loss of the entire second path can be adjusted by the tube diameter of the third heat transfer tube.

  In the heat exchanger according to the fourth aspect of the present invention, the tube diameter of the third heat transfer tube is the same as the tube diameter of the first heat transfer tube. The length of the at least one third heat transfer tube in the second path is shorter than the length of the at least one first heat transfer tube in the first path.

  In the heat exchanger according to the fourth aspect of the present invention, the length of at least one third heat transfer tube in the second path is shorter than the length of at least one first heat transfer tube in the first path. Thereby, the balance between the pressure loss in the first pass and the pressure loss in the second pass can be adjusted.

  In the heat exchanger according to the first aspect of the present invention, it is not necessary to provide a capillary tube in adjusting the pressure loss, so that it is possible to suppress a decrease in heat exchange performance. In addition, since the pressure loss is adjusted by the second pass having the heat exchange performance, the heat exchange performance can be improved not only in suppressing the decrease in the heat exchange performance.

  In the heat exchanger according to the second aspect of the present invention, the pressure loss of the entire second path can be adjusted by interposing at least one second heat transfer tube in front of at least two second heat transfer tubes.

  In the heat exchanger according to the third aspect of the present invention, since the tube diameter of the third heat transfer tube is smaller than the tube diameter of the second heat transfer tube, the pressure loss of the entire second path is adjusted by the tube diameter of the third heat transfer tube. can do.

  In the heat exchanger according to the fourth aspect of the present invention, the length of at least one third heat transfer tube in the second path is shorter than the length of at least one first heat transfer tube in the first path. The balance between the pressure loss and the pressure loss in the second pass can be adjusted.

It is a figure explaining the structure of an air conditioner provided with an indoor heat exchanger. It is sectional drawing of an air-conditioning indoor unit. It is a schematic diagram explaining an example of schematic structure of an indoor heat exchanger. It is a schematic diagram explaining an example of a detailed structure of an indoor heat exchanger. It is a schematic diagram explaining the other example of schematic structure of an indoor heat exchanger.

  Embodiments of the present invention are shown below. The following embodiments are merely specific examples and do not limit the invention according to the claims.

<First Embodiment>
(1) Air conditioner (1-1) Schematic configuration of air conditioner FIG. 1 shows a configuration of an air conditioner 100 including an indoor heat exchanger 400 as an example of a heat exchanger according to an embodiment of the present invention. It is a figure explaining. The air conditioner 100 includes an air conditioning outdoor unit 200 as a heat source side unit and an air conditioning indoor unit 300 as a use side unit. The air-conditioning outdoor unit 200 and the air-conditioning indoor unit 300 are connected to each other via a liquid refrigerant refrigerant communication pipe 101 and a gas refrigerant refrigerant communication pipe 102.

  The refrigerant circuit of the air conditioner 100 includes an air conditioning outdoor unit 200, an air conditioning indoor unit 300, a refrigerant communication pipe 101, and a refrigerant communication pipe 102. More specifically, the refrigerant circuit includes an expansion valve 203, a compressor 204, a four-way switching valve 205, an accumulator 206, an outdoor heat exchanger 207, and an indoor heat exchanger 400.

(1-2) Detailed Configuration of Air Conditioner (1-2-1) Air Conditioning Outdoor Unit The air conditioning outdoor unit 200 includes a gas refrigerant pipe 201, a liquid refrigerant pipe 202, an expansion valve 203, a compressor 204, and four A path switching valve 205, an accumulator 206, an outdoor heat exchanger 207, and an outdoor fan 208 are included. One end of the gas refrigerant pipe 201 is connected to the gas side end of the outdoor heat exchanger 207, and the other end of the gas refrigerant pipe 201 is connected to the four-way switching valve 205. One end of the liquid refrigerant pipe 202 is connected to the liquid side end of the outdoor heat exchanger 207, and the other end of the liquid refrigerant pipe 202 is connected to the expansion valve 203.

  The expansion valve 203 is a mechanism that depressurizes the refrigerant. The expansion valve 203 is provided between the outdoor heat exchanger 207 and the refrigerant communication pipe 101. The compressor 204 is a hermetic compressor driven by a compressor motor.

  The four-way switching valve 205 is a mechanism that switches the direction in which the refrigerant flows. During cooling operation, as shown by the solid line of the four-way switching valve 205 in FIG. 1, the four-way switching valve 205 connects the refrigerant pipe 201 on the discharge side of the compressor 204 and the gas refrigerant pipe 201 and passes through the accumulator 206. Thus, the refrigerant pipe on the suction side of the compressor 204 and the refrigerant communication pipe 102 are connected. On the other hand, during heating operation, as shown by the broken line of the four-way switching valve 205 in FIG. 1, the four-way switching valve 205 connects the refrigerant pipe on the discharge side of the compressor 204 and the refrigerant communication pipe 102 and also accumulator 206. Then, the refrigerant pipe on the suction side of the compressor 204 and the gas refrigerant pipe 201 are connected.

  The accumulator 206 divides the refrigerant into a gas phase and a liquid phase. The accumulator 206 is provided between the compressor 204 and the four-way switching valve 205.

  The outdoor heat exchanger 207 functions as a refrigerant condenser during the cooling operation, and functions as a refrigerant evaporator during the heating operation. The outdoor fan 208 supplies air to the outdoor heat exchanger 207.

(1-2-2) Air Conditioning Indoor Unit The air conditioning indoor unit 300 includes an indoor heat exchanger 400 and an indoor fan 301. The indoor heat exchanger 400 is, for example, a cross fin type fin-and-tube heat exchanger configured by heat transfer tubes and a large number of fins. The indoor heat exchanger 400 functions as a refrigerant evaporator during cooling operation to cool indoor air, and functions as a refrigerant condenser during heating operation to heat indoor air. The indoor fan 301 supplies air to the indoor heat exchanger 400.

(1-3) Operation of the air conditioner (1-3-1) Cooling operation The degree of opening of the expansion valve 203 is that the refrigerant is overheated at the outlet of the indoor heat exchanger 400 (that is, the gas side of the indoor heat exchanger 400). The degree is adjusted to be constant. The connection state of the four-way switching valve 205 during the cooling operation is as already described.

  In the refrigerant circuit in the above-described state, the refrigerant discharged from the compressor 204 flows into the outdoor heat exchanger 207 through the four-way switching valve 205, dissipates heat to the outdoor air, and is condensed. The refrigerant that has flowed out of the outdoor heat exchanger 207 expands when it passes through the expansion valve 203. Then, it flows into the indoor heat exchanger 400, absorbs heat from the indoor air, and evaporates.

(1-3-2) Heating Operation The opening degree of the expansion valve 203 is adjusted so that the degree of supercooling of the refrigerant at the outlet of the indoor heat exchanger 400 becomes constant at the target value of the degree of supercooling. The connection state of the four-way switching valve 205 during the heating operation is as already described.

  In the refrigerant circuit in the above state, the refrigerant discharged from the compressor 204 flows into the indoor heat exchanger 400 through the four-way switching valve 205, dissipates heat to the indoor air, and condenses. The refrigerant that has flowed out of the indoor heat exchanger 400 expands when it passes through the expansion valve 203. Then, it flows into the outdoor heat exchanger 207, absorbs heat from the outdoor air, and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger 207 passes through the four-way switching valve 205 and is again sucked into the compressor 204 and compressed.

(2) Detailed Configuration of Air Conditioning Indoor Unit FIG. 2 is a cross-sectional view of the air conditioning indoor unit 300. The air conditioning indoor unit 300 includes a main body casing 310 in addition to the indoor heat exchanger 400 and the indoor fan 301. In this specification, four directions of “front”, “back”, “up”, and “down” are defined as shown in FIG. By attaching the back (rear) side of the main casing 310 to the side wall WL, the air conditioning indoor unit 300 is installed on the side wall WL of the room RS.

  The body casing 310 houses the indoor fan 301, the indoor heat exchanger 400, and the like. A suction port 311 for sucking room air is formed in the upper part of the main body casing 310. An air outlet 312 for blowing out conditioned air is formed near the center of the lower portion of the main casing 310.

  The indoor fan 301 is a cross flow fan. The indoor fan 301 is disposed at a substantially central portion of the main body casing 310 in the vertical direction. The indoor fan 301 is connected to a fan motor.

  Indoor heat exchanger 400 has first fin group 410 and second fin group 420. Each of the first fin group 410 and the second fin group 420 includes a large number of fins stacked in the longitudinal direction of the air conditioning indoor unit 300 (the depth direction in the drawing). A plurality of heat transfer tubes 430 arranged in the longitudinal direction are attached to each of the first fin group 410 and the second fin group 420.

  The indoor heat exchanger 400 is disposed so as to cover a part of the indoor fan 301. More specifically, the indoor heat exchanger 400 is located near the upper part of the indoor fan 301, that is, from near the front lower side of the indoor fan 301 to near the rear upper side of the indoor fan 301. The first fin group 410 is located near the upper part of the indoor fan 301 and in front of the lower part of the indoor fan 301. The second fin group 420 is located from the vicinity of the upper portion of the indoor fan 301 to the middle rear of the indoor fan 301.

  When the indoor fan 301 is rotated by driving the fan motor, indoor air is sucked into the main body casing 310 from the suction port 311. The sucked air passes through the indoor heat exchanger 400, is guided through the guide channel leading to the outlet 312, and is finally blown out from the outlet 312.

(3) Indoor Heat Exchanger (3-1) Schematic Configuration FIG. 3 is a schematic diagram illustrating an example of a schematic configuration of the indoor heat exchanger 400. The indoor heat exchanger 400 includes a first flow divider 440, a first path 450, a second path 460 including a second flow divider 461, and a third flow divider 470. Note that the length of the heat transfer tube shown in FIG. 3 does not indicate the actual length of the heat transfer tube.

  An inlet / outlet at one end of the first diverter 440 is connected to a pipe 441 leading to the refrigerant communication pipe 101, and an inlet / outlet at the other end of the first diverter 440 is connected to a plurality of heat transfer tubes. In this embodiment, it is connected to nine heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, and 430i. The first flow divider 440 divides the refrigerant flowing through the refrigerant communication pipe 101 into nine heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, and 430i and discharges them. Nine heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, 430i are eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h as first heat transfer tubes, One heat transfer tube 430i as the second heat transfer tube.

  The eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h have the same tube diameter. The tube diameters of the eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h are smaller than the tube diameter of the heat transfer tube 430i.

  The first path 450 includes eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h. That is, it is comprised only by the 1st heat exchanger tube. Although described later in detail, in the present embodiment, the first path 450 is formed on the front side of the indoor heat exchanger 400.

  The second path 460 includes two heat transfer tubes 430j and 430k as second heat transfer tubes in addition to the second flow divider 461 and the heat transfer tubes 430i. The inlet / outlet at one end of the second flow divider 461 is connected to the heat transfer tube 430i, and the inlet / outlet at the other end of the second flow divider 461 is connected to the two heat transfer tubes 430j, 430k. That is, the two heat transfer tubes 430j and 430k are not directly connected to the inlet / outlet at the other end of the first flow divider 440, but are connected through one heat transfer tube 430i. One heat transfer tube 430i plays a role of adjusting the pressure loss. The second flow divider 461 divides the refrigerant flowing through the heat transfer tube 430i into two heat transfer tubes 430j and 430k and discharges it.

  The tube diameters of the heat transfer tubes 430j and 430k are the same as the tube diameter of the heat transfer tube 430i. That is, the three heat transfer tubes 430i, 430j, and 430k have the same tube diameter. Although described in detail later, in the present embodiment, the second path 460 is formed on the back side of the indoor heat exchanger 400.

  As described above, the flow path cross-sectional area of the second pass 460 changes in the middle of the second pass 460. More specifically, the flow path cross-sectional area of the second path 460 downstream of the second flow divider 461 is twice the flow path cross-sectional area of the second path 460 upstream of the second flow divider 461.

  The inlet / outlet at one end of the third flow divider 470 is connected to the eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h and the two heat transfer tubes 430j, 430k. The inlet / outlet at the other end of the third flow divider 470 is connected to a pipe 442 leading to the refrigerant communication pipe 102.

(3-2) Detailed Configuration FIG. 4 is a schematic diagram illustrating an example of a detailed configuration of the indoor heat exchanger 400. In FIG. 4, the broken line indicates a U-shaped tube that makes a U-turn of the refrigerant flow.

  The first fin group 410 includes an upper fin group 411 on the upper side and a lower fin group 412 on the lower side. The second fin group 420 includes a front fin group 421 on the front side and a rear fin group 422 on the rear side.

  The heat transfer tube 430 a is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 through the lower fin group 412.

  The heat transfer tube 430 b is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 via the lower fin group 412.

  The heat transfer tube 430 c is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 through the lower fin group 412.

  The heat transfer tube 430 d is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 via the lower fin group 412.

  The heat transfer tube 430 e is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 through the upper fin group 411.

  The heat transfer tube 430f is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 via the upper fin group 411.

  The heat transfer tube 430g is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 via the upper fin group 411.

  The heat transfer tube 430 h is connected to the inlet / outlet of one end of the third flow divider 470 from the first flow divider 440 via the upper fin group 411.

  The heat transfer tube 430 i is connected to the inlet / outlet of one end of the second flow divider 461 from the first flow divider 440 via the front fin group 421 and the rear fin group 422.

  The heat transfer tube 430j is connected to the inlet / outlet of one end of the third flow divider 470 from the second flow divider 461 via the rear fin group 422 and the front fin group 421.

  The heat transfer tube 430k is connected to the inlet / outlet of one end of the third flow divider 470 from the second flow divider 461 via the rear fin group 422 and the front fin group 421.

  Each of the eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h reciprocates three times in the longitudinal direction. That is, each of the eight heat transfer tubes 430 a, 430 b, 430 c, 430 d, 430 e, 430 f, 430 g, and 430 h reciprocates three times with respect to the first fin group 410.

  The heat transfer tube 430i reciprocates twice in the longitudinal direction. That is, the heat transfer tube 430 i reciprocates twice with respect to the second fin group 420.

  The heat transfer tube 430j reciprocates four times in the longitudinal direction. That is, the heat transfer tube 430j reciprocates four times with respect to the second fin group 420.

  The heat transfer tube 430k reciprocates five times in the longitudinal direction. That is, the heat transfer tube 430k reciprocates five times with respect to the second fin group 420.

  As described above, one of the two heat transfer tubes 430j and 430k reciprocates four times in the longitudinal direction, and the other reciprocates five times in the longitudinal direction. In this embodiment, in order to improve heat exchange performance, the number of reciprocations of the lower heat transfer tube 430k is greater than the number of reciprocations of the upper heat transfer tube 430j.

(3-3) Flow of Refrigerant The refrigerant is supplied from the refrigerant communication pipe 101. The refrigerant at this time is a liquid refrigerant. The refrigerant passes through the liquid side inlet / outlet pipe 441 of the indoor heat exchanger 400 and is supplied to the inlet / outlet at one end of the first flow divider 440. The refrigerant is divided into nine heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, and 430i connected to the nine inlets and outlets at the other end of the first flow divider 440. As described above, the refrigerant divided into the nine heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, and 430i passes through the first fin group 410 or the second fin group 420, It is supplied to the entrance / exit of one end of the third flow divider 470. The refrigerant merged in the third flow divider 470 flows from the inlet / outlet at the other end of the third flow divider 470 to the pipe 442 and is finally supplied to the refrigerant communication pipe 102. The refrigerant at this time is a gas refrigerant.

(4) Features of Indoor Heat Exchanger In the indoor heat exchanger 400 of the present embodiment, the first path 450 includes only eight heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h. The second path 460 includes three heat transfer tubes 430 i, 430 j, and 430 k and a second shunt 461. The tube diameters of the heat transfer tubes 430i, 430j, and 430k are larger than the tube diameters of the heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h. The flow path cross-sectional area of the second pass 460 changes in the middle of the second pass 460.

  Here, if a capillary tube is provided downstream of the first flow divider 440, the pressure loss can be adjusted by the capillary tube. However, in this case, the heat exchange performance deteriorates due to pressure loss in the capillary tube.

  In the indoor heat exchanger 400 of the present embodiment, the second path 460 does not include a capillary tube. More specifically, in the second path 460, the pressure loss is adjusted by one heat transfer tube 430i provided in front of the two heat transfer tubes 430j and 430k. Since the second path 460 does not include a capillary tube, a decrease in heat exchange performance can be suppressed. Since the adjustment of the pressure loss is performed by the heat transfer tube 430i having a heat exchange function, the heat exchange performance can be improved not only in suppressing the decrease in the heat exchange performance.

  In the indoor heat exchanger 400 of the present embodiment, the second path 460 pressure loss is adjusted by one heat transfer tube 430i provided in front of the two heat transfer tubes 430j and 430k. By adjusting the pressure loss in the second pass 460, the difference between the pressure loss in the first pass 450 and the pressure loss in the second pass 460 is reduced. Thereby, since the difference between the circulation amount of the refrigerant flowing through the first path 450 and the circulation amount of the refrigerant flowing through the second path 460 is reduced, it is possible to suppress a decrease in heat exchange performance.

  In the indoor heat exchanger 400 of the present embodiment, the heat transfer tubes 430a, 430b, 430c, 430d, 430e, 430f, 430g, and 430h and the heat transfer tube 430i do not merge in the middle path of the indoor heat exchanger 400. The pressure loss due to can be avoided. Therefore, it is possible to suppress a decrease in heat exchange performance.

<Modification>
A modification applicable to the embodiment of the present invention will be described.

(1) Modification A
In the above description, the number of the heat transfer tubes 430 constituting the first path is eight, and the number of the heat transfer tubes 430 constituting the second path is three. However, the heat transfer tubes 430 constituting the first path are as follows. And the number of heat transfer tubes 430 constituting the second path are not limited to these. It is determined appropriately according to the size of the indoor heat exchanger 400 and the like.

(2) Modification B
In the above description, the heat transfer tube 430i for adjusting the pressure loss is provided on the back surface portion of the indoor heat exchanger 400, but may be provided on the front surface portion. In the above description, the number of heat transfer tubes for adjusting the pressure loss is one, but is not limited thereto. The number of heat transfer tubes for adjusting the pressure loss may be two or more. For example, the position of the heat transfer tube 430i in FIG. 3 and the positions of the heat transfer tubes 430j and 430k may be interchanged. More specifically, the heat transfer tube 430i may be connected via the two heat transfer tubes 430j and 430k, instead of being directly connected to the inlet / outlet at the other end of the first flow divider 440. In this case, the heat transfer tubes 430j and 430k can be regarded as heat transfer tubes for adjusting pressure loss. In the above description, the refrigerant is divided into the heat transfer tubes 430j and 430k by the second flow divider 461 after the heat transfer tube 430i reciprocates twice with respect to the second fin group 420. You may shunt to 430j and 430k.

(3) Modification C
In the above description, the flow passage cross-sectional area of the second path 460 is changed in the middle by using the second flow divider 461, that is, by changing the number of heat transfer tubes 430 before and after the second flow divider 461. The second shunt 461 may not be used. That is, the number of heat transfer tubes 430 need not be changed. For example, the tube diameter of the heat transfer tube 430 may be changed during the second pass 460.

  FIG. 5 is a schematic diagram for explaining another example of the schematic configuration of the indoor heat exchanger 400. The indoor heat exchanger 400 includes a first flow divider 540, a first path 550, a second path 560, and a third flow divider 570. The length of the heat transfer tube shown in FIG. 6 does not indicate the actual length of the heat transfer tube.

  An inlet / outlet at one end of the first flow divider 540 is connected to a pipe 541 leading to the refrigerant communication pipe 101, and an inlet / outlet at the other end of the first flow divider 540 is connected to a plurality of heat transfer tubes. Here, it is connected to nine heat transfer tubes 530a, 530b, 530c, 530d, 530e, 530f, 530g, 530h, and 530i. The first flow divider 540 divides the refrigerant flowing through the refrigerant communication pipe 101 into nine heat transfer tubes 530a, 530b, 530c, 530d, 530e, 530f, 530g, 530h, and 530i and discharges the refrigerant. The nine heat transfer tubes 530a, 530b, 530c, 530d, 530e, 530f, 530g, 530h, and 530i are the six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f as the first heat transfer tubes, and the third heat transfer tubes. As three heat transfer tubes 530g, 530h, and 530i.

  The tube diameters of the six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f are equal to each other. The tube diameters of the three heat transfer tubes 530g, 530h, and 530i are equal to each other.

  The first path 550 includes six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f. That is, it is comprised only by the 1st heat exchanger tube. The first path 550 is formed on the front side of the indoor heat exchanger 400. The six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f reciprocate three times with respect to the first fin group 410, for example.

  The second path 560 includes three heat transfer tubes 530j, 530k, and 530m as the second heat transfer tubes in addition to the three heat transfer tubes 530g, 530h, and 530i. The tube diameters of the three heat transfer tubes 530j, 530k, and 530m are equal to each other. The tube diameters of the heat transfer tubes 530g, 530h, and 530i are smaller than the tube diameters of the heat transfer tubes 530j, 530k, and 530m. In this modification, the tube diameters of the heat transfer tubes 530g, 530h, and 530i are the same as the tube diameters of the six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f.

  Of the second path 560, the three heat transfer tubes 530g, 530h, and 530i are formed on the front surface 561 side of the indoor heat exchanger 400, and the three heat transfer tubes 530j, 530k, and 530m are the back surface 562 side of the indoor heat exchanger 400. Is formed. That is, the three heat transfer tubes 530g, 530h, and 530i are disposed upstream of the three heat transfer tubes 530j, 530k, and 530m. The three heat transfer tubes 530g, 530h, and 530i reciprocate twice with respect to the first fin group 410, for example. Two of the three heat transfer tubes 530j, 530k, and 530m reciprocate four times with respect to the second fin group 420, and the remaining one reciprocates three times with respect to the second fin group 420.

  One end of the heat transfer tube 530g is connected to one end of the heat transfer tube 530j between the front surface 561 and the back surface 562. That is, the heat transfer tube 530g and the heat transfer tube 530j constitute one heat transfer tube that connects the first flow divider 540 and the third flow divider 570. Since the tube diameter of the heat transfer tube 530g is smaller than the tube diameter of the heat transfer tube 530j, the flow path cross-sectional area changes in the middle of the one heat transfer tube.

  One end of the heat transfer tube 530h is connected to one end of the heat transfer tube 530k between the front surface 561 and the back surface 562. That is, the heat transfer tubes 530h and the heat transfer tubes 530k constitute one heat transfer tube that connects the first flow divider 540 and the third flow divider 570. Since the tube diameter of the heat transfer tube 530h is smaller than the tube diameter of the heat transfer tube 530k, the flow path cross-sectional area changes in the middle of the one heat transfer tube.

  One end of the heat transfer tube 530i is connected to one end of the heat transfer tube 530m between the front surface 561 and the back surface 562. That is, the heat transfer tube 530i and the heat transfer tube 530m constitute one heat transfer tube that connects the first flow divider 540 and the third flow divider 570. Since the tube diameter of the heat transfer tube 530i is smaller than the tube diameter of the heat transfer tube 530m, the flow path cross-sectional area changes in the middle of the one heat transfer tube.

  As described above, the flow path cross-sectional area of the second pass 560 changes in the middle of the second pass 560. More specifically, the three heat transfer tubes 530j, 530k, and 530m are not directly connected to the inlet / outlet at the other end of the first flow divider 540, but are connected through the three heat transfer tubes 530g, 530h, and 530i. ing. Since the tube diameters of the three heat transfer tubes 530g, 530h, and 530i are smaller than the tube diameters of the three heat transfer tubes 530j, 530k, and 530m, the three heat transfer tubes 530g, 530h, and 530i play a role of adjusting the pressure loss. .

  The lengths of the three heat transfer tubes 530g, 530h, and 530i in the second path 560 are shorter than the lengths of the six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f in the first path 550. Thereby, the balance between the pressure loss in the first pass 550 and the pressure loss in the second pass 560 can be adjusted. Note that the adjustment of the balance between the pressure loss in the first pass 550 and the pressure loss in the second pass 560 is appropriately determined according to the size of the indoor heat exchanger 400 and the like. Therefore, the lengths of all the heat transfer tubes 530g, 530h, and 530i are not necessarily shorter than the lengths of all the heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f. It is sufficient that at least one length of the three heat transfer tubes 530g, 530h, and 530i is shorter than at least one length of the six heat transfer tubes 530a, 530b, 530c, 530d, 530e, and 530f.

  The inlet / outlet at one end of the third flow divider 570 is connected to the six heat transfer tubes 530a, 530b, 530c, 530d, 530e, 530f and the three heat transfer tubes 530g, 530h, 530i. The inlet / outlet at the other end of the third flow divider 570 is connected to a pipe 542 that leads to the refrigerant communication pipe 102.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

400 Indoor heat exchanger 440 First shunt 450 First pass 460 Second pass 461 Second shunt

JP 2011-163741 A

Claims (4)

A first path (450) comprising only one or more first heat transfer tubes;
A second path (460) including one or more second heat transfer tubes;
A first flow divider (440) for diverting inflowing refrigerant into the first path and the second path;
With
The tube diameter of the second heat transfer tube is larger than the tube diameter of the first heat transfer tube,
The flow path cross-sectional area of the second pass changes during the second pass,
Heat exchanger. The second path includes three or more second heat transfer tubes and a second shunt (461).
The second flow divider divides the refrigerant that has entered from at least one second heat transfer tube into at least two second heat transfer tubes.
The heat exchanger according to claim 1. The second path includes one or more third heat transfer tubes,
The third heat transfer tube is disposed upstream of the second heat transfer tube,
The tube diameter of the third heat transfer tube is smaller than the tube diameter of the second heat transfer tube,
The heat exchanger according to claim 1. The tube diameter of the third heat transfer tube is the same as the tube diameter of the first heat transfer tube,
The length of at least one third heat transfer tube in the second path is shorter than the length of at least one first heat transfer tube in the first path,
The heat exchanger according to claim 3.

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