JP5957538B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner including a multi-pass heat exchanger.

  Since the flow loss on the refrigerant side increases as the diameter of the refrigerant flow path of the heat exchanger increases, reducing the loss by increasing the number of passes in the refrigerant flow path has been performed. Further, in the heat exchanger functioning as an evaporator, even when the number of passes is increased, if the distribution of the refrigerant in the gas-liquid two-phase state is not appropriate, there is a problem that the performance of the air conditioner decreases. As a technique for solving such a problem, in Japanese Patent Application Laid-Open No. H11-260260, a flow dividing pipe that once again divides the refrigerant flowing through each refrigerant pipe in the middle of the refrigerant pipes (refrigerant flow paths) divided into a plurality of paths, and then immediately divides the refrigerant pipe. A technique for providing the above has been proposed.

JP-A-8-313115

  However, in the technique described in Patent Document 1, the path is divided into the front and rear (upstream side and downstream side) with respect to the air flow direction, so the path located on the front side (upstream side in the air flow direction) Warm air flows, and air cooled on the front side flows through a path located on the rear side (downstream side in the air flow direction), and heat exchange cannot be performed efficiently.

  Therefore, if the refrigerant flow path of the heat exchanger is divided up and down rather than back and forth with respect to the direction of air flow, the distribution pipe is not horizontal when the distribution pipe (distribution pipe) is provided in the refrigerant pipe separated vertically. There is a problem that the refrigerant cannot be evenly distributed due to the influence of gravity and the heat exchange performance as an evaporator cannot be improved.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a high-performance air conditioner by exhibiting the heat exchange capability inherent to the evaporator.

  According to a first aspect of the present invention, there is provided a compressor for compressing a refrigerant, a condenser for condensing the refrigerant compressed by the compressor, a decompression device for decompressing the refrigerant condensed by the condenser, and a decompression by the decompression device. An evaporator for evaporating the refrigerant, wherein the evaporator is provided at one of a plurality of refrigerant flow paths divided at least partially in the vertical direction and at both ends of the plurality of refrigerant flow paths. A distributor for diverting the refrigerant to the plurality of refrigerant channels; a merger for merging the refrigerant flowing through the plurality of refrigerant channels to the other of the ends of the plurality of refrigerant channels; and the plurality of refrigerant channels A refrigerant passage that extends in a horizontal direction to exchange heat, and a bent passage that exits from the heat transfer passage and returns to the other heat transfer passage. And the communication path is located outside the bent flow path in the middle of the refrigerant flow path. It characterized in that it communicates with the side surface.

  According to a second aspect of the present invention, there is provided a compressor for compressing a refrigerant, a condenser for condensing the refrigerant compressed by the compressor, a decompression device for decompressing the refrigerant condensed by the condenser, and a decompression by the decompression device. An evaporator for evaporating the refrigerant, wherein the evaporator is provided at one of a plurality of refrigerant flow paths divided at least partially in the vertical direction and at both ends of the plurality of refrigerant flow paths. A distributor for diverting the refrigerant to the plurality of refrigerant channels; a merger for merging the refrigerant flowing through the plurality of refrigerant channels to the other of the ends of the plurality of refrigerant channels; and the plurality of refrigerant channels A refrigerant passage that extends in a horizontal direction to exchange heat, and a bent passage that exits from the heat transfer passage and returns to the other heat transfer passage. And the communication path is provided in the middle of the refrigerant flow path to cool the bent flow path. Characterized in that it communicates with the outer peripheral side surface of the immediately downstream.

  According to the present invention, a high-performance air conditioner can be provided by exhibiting the heat exchange capability inherent to the evaporator.

It is a whole block diagram which shows an air conditioner. It is a disassembled perspective view which shows the outline of the heat exchanger of an air conditioner. It is a perspective view which shows the heat exchanger which concerns on 1st Embodiment. The temperature change of the refrigerant | coolant in an evaporator is shown, (a) is a graph which shows the temperature change at the time of equal distribution, (b) is a graph which shows the temperature change at the time of non-uniform distribution. The pressure change of the refrigerant | coolant in an evaporator is shown, (a) is a pressure change at the time of equal distribution, (b) is a graph which shows the pressure change at the time of non-uniform distribution. The 1st installation system of a communicating path is shown, (a) is a top view, (b) is an AA sectional view. The 2nd installation system of a communicating path is shown, (a) is a top view, (b) is a BB sectional drawing. The 3rd installation system of a communicating path is shown, (a) is a top view, (b) is CC sectional view taken on the line. It is sectional drawing which shows the 4th installation system of a communicating path. A gas-liquid two-phase flow is shown, (a) is a separated flow, and (b) is an annular flow. It is a side view which shows the heat exchanger which concerns on 2nd Embodiment. It is a side view which shows the heat exchanger which concerns on 3rd Embodiment. It is a side view which shows the heat exchanger which concerns on 4th Embodiment.

  Embodiments of the present invention will be specifically described below with reference to the drawings. First, the whole structure of the air conditioner 1 is demonstrated with reference to FIG. In the first embodiment shown in FIG. 3, a simplified heat exchanger, in the second embodiment shown in FIG. 11, an outdoor heat exchanger of a domestic air conditioner, the third embodiment shown in FIG. In the fourth embodiment shown in FIG. 13, an indoor heat exchanger of a domestic air conditioner will be described as an example. Note that the present invention is not limited to home use and can be applied to a commercial air conditioner.

  As shown in FIG. 1, the air conditioner 1 mainly includes a compressor 2, an indoor heat exchanger 3, a pressure reducing device 4 (such as an expansion valve), an outdoor heat exchanger 5, a four-way valve 6, and the like. These element devices are sequentially connected by refrigerant pipes 120, 121, 122, 123, 124, and 125. Although not shown, for example, the indoor heat exchanger 3 is provided with a once-through fan, and the outdoor heat exchanger 5 is provided with a propeller fan.

  During the cooling operation, the outdoor heat exchanger 5 functions as a condenser, and the indoor heat exchanger 3 functions as an evaporator. At this time, as indicated by solid arrows, the refrigerant is the compressor 2, the refrigerant pipe 120, the four-way valve 6, the refrigerant pipe 121, the outdoor heat exchanger 5, the refrigerant pipe 122, the decompression device 4, the refrigerant pipe 123, and the indoor heat exchanger. 3, the refrigerant pipe 124, the four-way valve 6, the refrigerant pipe 125, and the compressor 2 are circulated in the air conditioner 1 while changing the state in this order.

  Specifically, the refrigerant compressed by the compressor 2 and discharged in a high-pressure and high-temperature vapor state flows into the outdoor heat exchanger 5, releases heat therein, and changes to a high-pressure and medium-temperature liquid refrigerant. The liquid refrigerant passes through the decompression device 4 and enters a low-pressure and low-temperature gas-liquid two-phase state (gas-liquid two-phase flow), and then takes heat from the surroundings (indoor air) in the indoor heat exchanger 3 to reduce the pressure. The cycle of a low-temperature steam state (gas state) and suction into the compressor 2 is repeated.

  On the other hand, when the flow direction of the refrigerant is switched by the four-way valve 6, the heating operation is performed. In that case, the outdoor heat exchanger 5 functions as an evaporator, and the indoor heat exchanger 3 functions as a condenser. At this time, as indicated by broken line arrows, the refrigerant is the compressor 2, the refrigerant pipe 120, the four-way valve 6, the refrigerant pipe 124, the indoor heat exchanger 3, the refrigerant pipe 123, the decompression device 4, the refrigerant pipe 122, and the outdoor heat exchanger. 5, the refrigerant pipe 121, the four-way valve 6, the refrigerant pipe 125, and the compressor 2 are circulated through the air conditioner 1 in this order.

FIG. 2 is an exploded perspective view schematically showing a heat exchanger of the air conditioner.
As shown in FIG. 2, the heat exchanger used as the indoor heat exchanger 3 or the outdoor heat exchanger 5 is, for example, a cross fin tube type heat exchanger, and a plurality of aluminum fins 100 are A copper U-shaped heat transfer tube 110 bent in a U-shape (a heat transfer channel, hereinafter abbreviated as the heat transfer tube 110) penetrates. The fin 100 and the heat transfer tube 110 are brought into close contact with each other by expanding the heat transfer tube 110 inserted into the fin 100 either hydraulically or mechanically. The heat transfer tube 110 has a structure that extends in a substantially horizontal direction (a direction perpendicular to the vertical direction) and penetrates the fins 100.

  In addition, a return bend (joint part) 111 for connecting to the end of another heat transfer tube 110 is joined to the end of the heat transfer tube 110 by welding or the like to form a refrigerant flow path. As described above, the heat exchanger has flow paths that meander while being folded at both ends in the stacking direction of the fins 100. The return bend 111 is not limited to a U-shape as will be described later.

  In addition, the part which the fin 100 and the heat exchanger tube 110 contact | connect and the air flows between the fin 100 and the fin 100 respond | corresponds to the heat exchange area | region of a heat exchanger. The U-shaped tube portion of the heat transfer tube 110 on one end side in the stacking direction of the fins 100 and the return bend 111 portion on the other end side are regions that do not contribute to heat exchange.

(First embodiment)
FIG. 3 is a perspective view showing the heat exchanger according to the first embodiment. In addition, the arrow (solid line) in a figure has shown the direction through which a refrigerant | coolant flows when a heat exchanger functions as an evaporator. For example, the heat exchanger shown in FIG. 3 is the outdoor heat exchanger 5 in the case of heating operation.

  As shown in FIG. 3, the heat exchanger according to the first embodiment includes a plurality of refrigerant flow paths 30 and 40 divided into two paths, a distributor 11, a merger 12, and a communication pipe 990 (communication path). It consists of

  The refrigerant flow path 30 is disposed in a region above the central portion in the vertical direction (vertical direction) of the heat exchanger (see an arrow pointing upward with respect to the alternate long and short dash line), and the refrigerant flow path 40 is vertical to the heat exchanger. It arrange | positions in the area | region below the center part of a direction (up-down direction) (refer the downward arrow with respect to a dashed-dotted line). As described above, the refrigerant flow path 30 and the refrigerant flow path 40 are not arranged forward and backward with respect to the air flow direction, but are arranged vertically in the vertical direction orthogonal to the air flow direction. is there.

  The distributor 11 has a bifurcated shape connected to one of the both ends of the refrigerant flow paths 30 and 40 (inlet 110a and 110b). The distributor 11 is decompressed by the decompression device 4 (see FIG. 1), and the gas-liquid The refrigerant in the two-phase state is divided (distributed) into the refrigerant flow path 30 and the refrigerant flow path 40.

  The merger 12 has a bifurcated shape that is connected to the other end (the outlets 110c and 110d) of both ends of the refrigerant flow paths 30 and 40, and merges the refrigerant in a vapor state.

  The communication pipe 990 connects the return bend 111A (111) in the middle of the refrigerant flow path 30 and the return bend 111B (111) in the middle of the refrigerant flow path 40 so that the refrigerant flow path 30 and the refrigerant flow path 40 are connected. A communication channel is formed. In addition, the arrow shown in the communication pipe 990 indicates the direction in which the refrigerant flows when the pressure of the refrigerant flow path 40 is higher than the pressure of the refrigerant flow path 30 during the uneven distribution described later. The detailed configuration of the communication pipe 990 will be described later.

  In the refrigerant flow path 30 shown in FIG. 3, for example, the refrigerant flows upward in the vertical direction while meandering the flow path located on the front side (upstream side) with respect to the air flow direction (see the arrow in the figure) from the inlet 110a. It flows downward in the vertical direction while meandering the flow path located on the rear side (downstream side) with respect to the air flow direction at the uppermost part of the heat exchanger, and exits from the outlet 110c to the merger 12.

  Further, in the refrigerant flow path 40 shown in FIG. 3, for example, the refrigerant flows downward in the vertical direction while meandering the flow path located on the front side (upstream side) with respect to the air flow direction from the inlet 110 b, and the heat exchanger The lowermost part flows in the vertical direction while meandering the flow path located on the rear side (downstream side) with respect to the air flow direction, exits the outlet 110d, reaches the merger 12, and merges with the refrigerant flow path 30.

  In the heat exchanger according to the first embodiment configured as described above, the refrigerant to the refrigerant channel 30 passes through the upper part of the heat exchanger (evaporator), and the refrigerant to the refrigerant channel 40 is the heat exchanger (evaporation). The refrigerant evaporates through heat exchange with air sent by a fan (not shown) through the lower part of the vessel. Then, the refrigerant merges at the merger 12 and flows to the compressor 2.

  FIG. 4 shows the temperature change of the refrigerant in the evaporator, (a) is a graph showing the temperature change at the time of even distribution, and (b) is a graph showing the temperature change at the time of non-uniform distribution. In addition, the broken line of FIG.4 (b) shows the temperature change of the refrigerant | coolant which passes the refrigerant flow path 30, and a continuous line shows the temperature change of the refrigerant | coolant which passes the refrigerant flow path 40. FIG. FIG. 4A shows a case where the temperature change of the refrigerant flow path 30 and the temperature change of the refrigerant flow path 40 coincide with each other.

  Further, the “distance from the inlet” shown on the horizontal axis in FIG. 4 is a distance (length) when the inlets 110a and 110b are used as a reference. The “full length per pass” means the total length of the pipes of the refrigerant flow paths 30 and 40, and the heat transfer pipe 110 (see FIG. 3) and the return bend from the inlets 110a and 110b to the outlets 110c and 110d. 111 (see FIG. 3). Accordingly, when the numerical value (percentage) of the horizontal axis (distance from the entrance / total length per path) is low, the distance is closer to the entrances 110a and 110b, and the distance (exit) becomes farther from the entrances 110a and 110b as the numerical value (percentage) increases. 110c and 110d).

  The “inlet” is not limited to the inlets 110a and 110b shown in FIG. 3, and may be a branch point P (see FIG. 3) of the distributor 11. In addition, for the “total length per pass”, the U-shaped portion of the heat transfer tube 110 and the portion of the return bend 111 that protrude outward from the end of the fin 100 in the stacking direction are portions that do not contribute to heat exchange. The portion excluding these portions may be set as “the total length per pass”.

  By the way, as shown to Fig.4 (a), when a refrigerant | coolant equally divides | distributes in the divider | distributor 11 (The flow volume of the liquid refrigerant to each refrigerant flow path 30 and 40 and the flow volume of a gas refrigerant are the same), The refrigerant temperature in the refrigerant flow path 30 and the refrigerant temperature in the refrigerant flow path 40 show substantially the same change, and the original heat exchange capability of the evaporator can be exhibited.

  However, depending on the shape of the pipe attached to the upstream side of the distributor 11, there may be a bias between the gas-liquid two-phase flow gas refrigerant and the liquid refrigerant. The shape of the pipe attached to the upstream side of the distributor 11 is generally that the space on the upstream side of the distributor 11 is narrow, and the pipe straight to the inlets 110a and 110b (see FIG. 3) is used. It is rarely attached, meaning that a bent pipe such as an L-shape may be attached, that is, centrifugal force may be generated with respect to the refrigerant.

  For example, when an uneven refrigerant distribution occurs in which the amount of liquid refrigerant flowing to the refrigerant flow path 40 is larger than that of the refrigerant flow path 30, the refrigerant temperature in the refrigerant flow path 40 is as shown in FIG. Decreases toward the outlet 110d (see FIG. 3). On the other hand, in the refrigerant flow path 30, the refrigerant temperature rises to the vicinity of the air temperature (not shown) with the end of evaporation from the liquid refrigerant to the gas refrigerant in the middle of the refrigerant flow path 30, and the flow paths thereafter Effective heat exchange is not performed in the flow path in the vicinity of the outlet 110c of the refrigerant flow path 30. As a result, the performance as an air conditioner decreases.

  Therefore, in order to prevent the deterioration of the heat exchange performance of the evaporator due to the uneven refrigerant distribution as shown in FIG. 4B, in the first embodiment, for example, a return bend in the middle of the refrigerant flow path 30 is used. A communication pipe 990 (communication path) that connects 111A (111) and a return bend 111B (111) in the middle of the refrigerant flow path 40 is provided, and the refrigerant flow path 30 and the refrigerant flow path 40 are communicated with each other. It is a thing.

  FIG. 5 is a graph showing the pressure change of the refrigerant in the evaporator, (a) is a pressure change at the time of even distribution, and (b) is a graph showing the pressure change at the time of non-uniform distribution. The broken line in FIG. 5B indicates the pressure change of the refrigerant passing through the refrigerant flow path 30, and the solid line indicates the pressure change of the refrigerant passing through the refrigerant flow path 40. FIG. 5A shows a case where the pressure change in the refrigerant flow path 30 matches the pressure change in the refrigerant flow path 40.

  As shown in FIG. 5A, when the gas-liquid two-phase flow refrigerant is evenly distributed, the refrigerant pressure changes in the refrigerant flow path 30 and the refrigerant flow path 40 are the same. On the other hand, when uneven refrigerant distribution occurs, the flow rate of the liquid refrigerant flowing through the refrigerant flow path 30 is smaller than that of the refrigerant flow path 40 into which more liquid refrigerant has flowed, and therefore, It progresses quickly and the dryness increases rapidly. Accordingly, in the refrigerant flow path 30, as shown in FIG. 5 (b), the refrigerant pressure initially drops at a faster pace, but if it exceeds a certain position (distance from the inlet / total length per pass), the refrigerant pressure Of the refrigerant flow path 40 becomes slower than the pressure drop speed of the refrigerant flow path 40, and the refrigerant pressures of the refrigerant flow paths 30 and 40 become the same at the outlets 110c and 110d. That is, the refrigerant pressure changes in the refrigerant flow paths 30 and 40 are different, and a pressure difference exists between the refrigerant flow path 30 and the refrigerant flow path 40 in the middle of the refrigerant flow paths 30 and 40.

  In the present embodiment, the heat exchange performance of the evaporator is improved by using the pressure difference existing between the refrigerant flow path 30 and the refrigerant flow path 40 and moving the liquid refrigerant. It is.

  As shown in FIG. 5B, when the flow rates of the liquid refrigerant and the gas refrigerant flowing through the refrigerant flow paths 30 and 40 are different, the refrigerant flow path 30 and the refrigerant flow are arranged in the middle of the refrigerant flow paths 30 and 40. There is a pressure difference with the passage 40. Therefore, by providing the communication pipe 990 (see FIG. 3), the refrigerant moves from the high-pressure refrigerant flow path 40 to the low-pressure refrigerant flow path 30 through the communication pipe 990 according to the pressure difference ( (See arrow in FIG. 3).

  When the refrigerant passing through the communication pipe 990 is a liquid refrigerant, the evaporation progresses quickly, and the refrigerant dryness is higher than the refrigerant flow path 40 (that is, the ratio of the liquid refrigerant is small). Supplied. Therefore, the end of evaporation is delayed as compared with the case where the communication pipe 990 is not provided (see FIG. 4B), so that the heat transfer area of the heat exchanger can be used effectively. In addition, since the liquid refrigerant decreases in the refrigerant flow path 40, the problem that evaporation does not end and the liquid refrigerant returns to the compressor can be solved.

  However, when the refrigerant passing through the communication pipe 990 is a gas, the gas refrigerant is supplied to the refrigerant flow path 30 having a higher dryness than the refrigerant flow path 40, and as the dryness becomes higher, the communication pipe 990 is connected. Evaporation is completed earlier than if it is not provided, increasing the heat transfer area that cannot be used effectively. On the other hand, in the refrigerant flow path 40, the heat transfer performance is impaired as the gas refrigerant decreases, and the progress of evaporation is slower than when the communication pipe 990 is not provided. As a result, the performance of the heat exchanger is degraded.

  Therefore, a means for moving only the liquid refrigerant, not the gas refrigerant, to the communication pipe 990 is required. The means will be described with reference to FIGS. 6 is a cross-sectional view showing a first installation method of the communication passage, FIG. 7 is a cross-sectional view showing a second installation method of the communication passage, FIG. 8 is a cross-sectional view showing a third installation method of the communication passage, and FIG. FIG. 10 is a cross-sectional view showing a fourth installation method of the communication path, FIG. 10 shows a gas-liquid two-phase flow, (a) is a separated flow, and (b) is an annular flow.

  In the first installation method shown in FIG. 6, a bent pipe 111a (a range surrounded by a bent flow path and a one-dot chain line) is bent at one end of the communication pipe 990 in a semicircular shape of the return bends 111A (111) and 111B (111). ) Outer peripheral surface 111b (the outer peripheral surface, the outer surface of the bend).

  Thus, when the gas-liquid two-phase flow passes through the bent pipe 111a, the liquid refrigerant having a high density moves on the inner wall surface on the outer peripheral surface 111b side of the bent pipe 111a by the action of the centrifugal force. On the other hand, the gas refrigerant moves on the inner wall surface on the inner peripheral surface 111c side of the bent pipe 111a. Therefore, when the refrigerant pressure in the refrigerant channel 30 is lower than the refrigerant pressure in the refrigerant channel 40 (see FIG. 5B), the communication pipe 990 connected to the outer peripheral surface 111b of the bent pipe 111a of the return bend 111B. The liquid refrigerant flows into the refrigerant flow path 40 on the return bend 111A side.

  As described above, the communication pipe 990 is not simply connected to the return bends 111A and 111B but is connected to the outer peripheral surface 111b of the bent pipe 111a of the return bends 111A and 111B. It is possible to prevent the refrigerant moving through the gas phase from being a gas phase and to allow the liquid refrigerant to flow.

  As a result, the liquid refrigerant flows from the refrigerant flow path 40 having a low dryness to the refrigerant flow path 30 having a high dryness. Accordingly, the liquid refrigerant is supplied in the refrigerant flow path 30 with a high dryness, and at the same time, the liquid refrigerant decreases in the refrigerant flow path 40 with a low dryness. That is, in the refrigerant flow path after the communication pipe 990, the difference in the refrigerant state is reduced, and the difference in the degree of evaporation of the refrigerant existing between the refrigerant flow path 30 and the refrigerant flow path 40 is also reduced.

  Note that when the gas-liquid two-phase flow refrigerant is evenly distributed, there is no pressure difference between the refrigerant flow path 30 and the refrigerant flow path 40 as shown in FIG. Even if the pipe 990 is provided, the refrigerant does not move. That is, the performance of the heat exchanger is not impaired by the installation of the communication pipe 990.

  Although FIG. 6 illustrates a case where the communication pipe 990 is connected to an intermediate position between one end and the other end of the bent pipe 111a, the liquid refrigerant can move to the inner wall surface on the outer peripheral face 111b side of the bent pipe 111a. The position is not limited to the intermediate position. In the case of the first installation method, as shown by the broken line in FIG. 6, even if the refrigerant is introduced from one of the return bends 111A and 111B, as shown by the solid line in FIG. Even if it is a case where a refrigerant | coolant is introduce | transduced from the other of 111A and 111B, it is applicable.

  As described above, in the first embodiment, the communication pipe 990 is connected in the middle of the refrigerant flow paths 30 and 40 even if the plurality of refrigerant flow paths 30 and 40 are heat exchangers that are vertically separated from each other. In addition, by connecting the communication pipe 990 to the outer peripheral surface 111b of the bent pipe 111a, in the refrigerant flow path after the communication pipe 990, the evaporation of the refrigerant existing between the refrigerant flow paths progresses as the liquid refrigerant moves. The difference in degree can be reduced, and the heat exchange performance as an evaporator and the equipment performance of the air conditioner 1 can be improved. Moreover, since the structure of the communication pipe 990 is extremely simple, it can be manufactured at a very low cost.

  Further, in the first embodiment, the communication pipe 990 is made substantially the same distance from the distributor 11 of the refrigerant flow paths 30 and 40 (for example, the refrigerant flow paths 30 and 40 both have the refrigerant on the outlet side of the second heat transfer pipe 110). It is preferable.

  When the refrigerant distribution is uneven (see FIG. 5B), for example, the outlet of the second heat transfer tube 110 of the refrigerant flow path 30 and the outlet of the third heat transfer pipe 110 of the refrigerant flow path 40 are communicated. When the pipe 990 is connected, the lengths of the refrigerant flow path 30 and the refrigerant flow path 40 upstream of the communication pipe are different. In that case, since there is almost no pressure difference between the refrigerant flow path 30 and the refrigerant flow path 40, no movement of the refrigerant occurs and there is no effect of providing the communication pipe 990. Alternatively, since the pressure in the refrigerant channel 40 is lower than that in the refrigerant channel 30, the liquid refrigerant moves from the refrigerant channel 30 to the refrigerant channel 40. As a result, in the refrigerant flow path 30 after the communication pipe 990, the liquid refrigerant becomes less than in the case where the communication pipe 990 is not provided, and the liquid refrigerant 30 is overheated earlier. On the other hand, in the refrigerant flow path 40 after the communication pipe 990, the liquid refrigerant becomes larger than in the case where the communication pipe 990 is not provided, so that the evaporation of the refrigerant cannot be completed.

  For example, when the outlet of the third heat transfer tube 110 of the refrigerant flow path 30 and the outlet of the second heat transfer pipe 110 of the refrigerant flow path 40 are connected by the communication pipe 990, the refrigerant flow path 30 and the refrigerant flow upstream of the communication pipe The length with the path 40 is different. In that case, a large pressure difference exists between the refrigerant flow path 30 and the refrigerant flow path 40, so that a large amount of liquid refrigerant flows from the refrigerant flow path 40 to the refrigerant flow path 30. However, in the refrigerant flow path 30, since there are only two heat transfer pipes downstream of the communication pipe 990, it is impossible to complete the evaporation of the refrigerant. On the other hand, in the refrigerant flow path 40, the refrigerant passes through the three downstream pipes of the communication pipe 990. There is a possibility that a problem of overheating occurs early through the heat transfer tube. As a result, the performance of the heat exchanger cannot be improved.

  In addition, when the refrigerant distribution is uniform (see FIG. 5A), if the liquid refrigerant moves between the refrigerant flow paths, the refrigerant flow in which the liquid refrigerant increases cannot evaporate the refrigerant, In the refrigerant flow path in which the liquid refrigerant decreases, the evaporation of the refrigerant ends quickly. Therefore, the performance of the heat exchanger is impaired.

  As described above, in any of the cases described above, the performance of the heat exchanger cannot be improved if the communication pipe is provided at a place where the distance from the inlet of the heat exchanger is different. Therefore, as in the first embodiment, by setting the communication pipe 990 to substantially the same distance from the distributor 11 of the refrigerant flow paths 30 and 40, the heat transfer area of the heat exchanger can be used effectively, The performance of the exchanger can be improved.

  In the first embodiment, it is preferable to provide the communication pipe 990 in a place where the pressure difference between the refrigerant flow path 30 and the refrigerant flow path 40 becomes large, for example, in the range Q shown in FIG. Incidentally, even if the communication pipe is provided in a place where the pressure difference is very small, the pressure of each refrigerant flow path 30, 40 hardly changes, and the effect of providing the communication pipe may be lost at all.

  The installation method of the communication pipe 990 is not limited to that shown in FIG. For example, as shown in FIG. 7, as a second installation method, the communication pipe 991 is connected to the outer peripheral surface 111d immediately after the refrigerant downstream side of the bent pipe 111a (bent flow path) of the return bends 111A and 111B. Good. Even in such an installation method, the liquid refrigerant can move to the outer peripheral surface 111d immediately after the bent tube 111a while maintaining the state where the liquid refrigerant has moved to the outer peripheral surface 111b side of the bent tube 111a by the action of centrifugal force. In 991, only the liquid refrigerant flows.

  As shown in FIG. 8, as the third installation method, in the refrigerant pipes 142 and 143 having an L-shaped cross section, the bent pipes 142 a and 143 a (bends) of the refrigerant pipes 142 and 143 are the same as the second installation method. You may make it connect the communicating pipe | tube 991 to the outer peripheral surfaces 142b and 143b immediately after the refrigerant | coolant downstream of a flow path and the dashed-dotted line (refer the communicating pipe | tube 991 of FIG. 11 mentioned later). Even in such an installation method, the liquid refrigerant flows into the communication pipe 990 by the action of centrifugal force.

  Further, as shown in FIG. 9, a communication tube 991 may be connected to the bottom surface 110 e of the heat transfer tube 110 that penetrates the fins 100 of the heat exchanger and protrudes from the heat exchange region. In such a heat exchanger, since the heat transfer tube 110 is arranged almost horizontally, the flow state in the heat transfer tube 110 due to the influence of gravity is such that the liquid refrigerant is in the heat transfer tube 110 as shown in FIG. The bottom part is a so-called separated flow in which the gas refrigerant flows above the heat transfer tube 110, or the liquid refrigerant is on the inner wall surface of the heat transfer tube 110 and the gas refrigerant is in the center of the ring section of the heat transfer tube 110, as shown in FIG. In any case of a so-called annular flow flowing through the section, only the liquid refrigerant flows into the communication pipe 991 connected to the bottom surface 110e (tube wall surface) of the heat transfer tube 110.

  In the first embodiment, the case where the communication pipe 990 is connected to the return bends 111A and 111B has been described as an example. However, on the opposite side of the return bends 111A and 111B across the heat exchange region of the heat exchanger. The communication tube 990 may be connected to the U-shaped tube portion 110s (see FIG. 2) of the heat transfer tube 110.

  Further, the communication pipe 990 is not limited to the one that is joined to the return bends 111A and 111B, the refrigerant pipes 142 and 143, and the heat transfer pipe 110 by welding, and may be integrally formed.

  In the first embodiment, the case where the communication pipe 990 is provided at only one place has been described as an example. However, the present invention is not limited to one place, and may be provided at two or more places as described later. . Thereby, the difference in the refrigerant state between the refrigerant flow paths 30 and 40 can be further reduced.

(Second Embodiment)
FIG. 11 is a side view showing a heat exchanger according to the second embodiment. In addition, FIG. 11 shows an example of a household outdoor heat exchanger, the broken line in FIG. 11 shows the U-shaped tube portion of the heat transfer tube (corresponding to the heat transfer tube 110 in FIG. 2), Direction of refrigerant flow when the heat exchanger functions as an evaporator (direction of refrigerant flow during heating operation, that is, when the outdoor heat exchanger 5 functions as an evaporator and the indoor heat exchanger 3 functions as a condenser) ). Moreover, the piping shown with a thick continuous line has shown the communicating pipe | tube 991,992,993 corresponding to the communicating path of a claim.

  As shown in FIG. 11, in the heat exchanger (evaporator) according to the second embodiment, the decompression device 4 (see FIG. 1) and the distributor 933 are connected via the refrigerant pipe 122. It is divided into two refrigerant channels 31 and a refrigerant channel 41.

  One refrigerant flow path 31 passes through the refrigerant pipe 140 connecting the distributor 933 and the heat transfer pipe open end 301 (one end) of the heat transfer pipe 351, passes through the heat transfer pipes 351 and 352 at the lower part of the heat exchanger, and passes through the refrigerant pipe. The refrigerant reaches the distributor 953 via the refrigerant pipe 142 connected to the heat transfer pipe opening end 304 of the heat pipe 352, and is divided into two refrigerant flow paths 51 and 61 by the distributor 953. The refrigerant channel 51 and the refrigerant channel 61 are divided into upper and lower parts in the vertical direction.

  The refrigerant flow path 51 passes through the refrigerant pipe 144 that connects the distributor 953 and the heat transfer pipe opening end 501 of the heat transfer pipe 551, and the heat transfer pipes 551, 552, 553, 554, 555 556 at the uppermost part of the heat exchanger. Through to the merger 954 (the other end).

  The refrigerant flow path 61 passes through the heat transfer pipes 651, 652, 653, 654, 655 and 656 in the upper part of the heat exchanger via the refrigerant pipe 145 connecting the distributor 953 and the heat transfer pipe open end 601 of the heat transfer pipe 651. The merger 954 merges with the refrigerant flow path 51.

  The other refrigerant channel 41 passes through the refrigerant pipe 141 connecting the distributor 933 and the heat transfer pipe opening end 401 (one end) of the heat transfer pipe 451, passes through the heat transfer pipes 451 and 452 at the lowermost part of the heat exchanger, The refrigerant reaches the distributor 973 via the refrigerant pipe 143 connected to the heat transfer pipe opening end 404 of the heat transfer pipe 452, and is divided into two refrigerant flow paths 71 and a refrigerant flow path 81 by the distributor 973. The refrigerant channel 71 and the refrigerant channel 81 are divided into upper and lower parts in the vertical direction. Further, the refrigerant flow path 71 and the refrigerant flow path 81 are located below the refrigerant flow path 51 and the refrigerant flow path 61 in the vertical direction.

  The refrigerant flow path 71 passes through the refrigerant pipe 146 connecting the distributor 973 and the heat transfer pipe open end 701 of the heat transfer pipe 751, and connects the heat transfer pipes 751, 752, 753, 754, 755 756 in the middle part of the heat exchanger. To the merger 974 (the other end).

  The refrigerant flow path 81 passes through the refrigerant pipe 147 connecting the distributor 973 and the heat transfer pipe open end 801 of the heat transfer pipe 851, and passes through the heat transfer pipes 851, 852, 853, 854, 855, and 856 at the lower part of the heat exchanger. The merger 974 merges with the refrigerant flow path 71.

  In the merger 954, the refrigerant flow path 51 and the refrigerant flow path 61 merge. In the merger 974, the refrigerant flow path 71 and the refrigerant flow path 81 merge, and further merge via the refrigerant pipe 148 and the refrigerant pipe 149. After becoming a single refrigerant flow path in the vessel 934, it is connected to the compressor 2 (see FIG. 1) via the refrigerant pipe 121.

  Thus, in the second embodiment, the refrigerant pipe 142 and the refrigerant pipe 143 are connected by the communication pipe 991 in the middle of the refrigerant flow path 31 and the refrigerant flow path 41, and the refrigerant flow path 31 and the refrigerant flow path 41 are connected. Is communicated. Further, in the middle of the refrigerant flow path 51 and the refrigerant flow path 61, a return bend 111C (111) that connects the heat transfer pipe 552 and the heat transfer pipe 553, and a return bend 111D (111) that connects the heat transfer pipe 652 and the heat transfer pipe 653, respectively. ) Are connected by a communication pipe 992, and the refrigerant flow path 51 and the refrigerant flow path 61 are communicated with each other. Further, in the middle of the refrigerant flow path 71 and the refrigerant flow path 81, a return bend 111E (111) that connects the heat transfer pipe 752 and the heat transfer pipe 753, and a return bend 111F (111) that connects the heat transfer pipe 852 and the heat transfer pipe 853. ) Are connected by a communication pipe 993 to communicate the refrigerant flow path 71 and the refrigerant flow path 81.

  In addition, the communication pipe 991 has outer peripheral surfaces (outer peripheral surfaces, outer surfaces of the curves) 142b, 143b immediately after the refrigerant downstream side of the bent pipes 142a, 143a (see FIG. 8B) of the refrigerant pipes 142, 143. (See FIG. 8B) are connected to each other (see FIG. 8). The communication pipe 992 includes an outer peripheral surface (an outer peripheral surface, an outer surface of the bend) 111b (see FIG. 6) of the bent tube 111a of the return bend 111C, and an outer peripheral surface (an outer peripheral surface of the return bend 111D). It is connected to the outer surface 111b (see FIG. 6) of the bend. The communication pipe 993 includes an outer peripheral surface (an outer peripheral surface, an outer surface of the bend) 111b (see FIG. 6) of the bent tube 111a of the return bend 111E, and an outer peripheral surface (an outer peripheral surface of the bent tube 111a of the return bend 111F. It is connected to the outer surface 111b (see FIG. 6) of the bend.

  According to the heat exchanger (evaporator) according to the second embodiment, as in the first embodiment, the plurality of refrigerant flow paths 31, 41 (51, 61/71, 81) are separated from each other in the vertical direction. Even in the heat exchanger, the communication pipe 991 (992/993) is connected in the middle of the refrigerant flow paths 31, 41 (51, 61/71, 81), and the communication pipe 991 is connected to the refrigerant pipes 142, 143. The heat exchange performance is achieved by connecting the outer peripheral surfaces 142b and 143b (the communication pipes 992 and 993 to the outer peripheral surface 111b of the return bends 111E and 111F) of the bent pipes 142a and 143a immediately downstream of the refrigerant flow direction. Can be improved.

  Further, the state of the refrigerant in front of the distributor 953 (upstream) and the state of the refrigerant in front of the distributor 973 (upstream) are made substantially the same by the communication pipe 991. The refrigerant flowing through the refrigerant flow path 51, the refrigerant flow path 61, the refrigerant flow path 71, and the refrigerant flow path 81 by the communication pipe 992 and the communication pipe 993 show substantially the same state change, and the original heat exchange capability of the evaporator And the performance of the air conditioner 1 is improved.

  In this way, the difference in the degree of evaporation of the refrigerant between the refrigerant channels can be reduced, and the heat exchange performance as an evaporator and the equipment performance of the air conditioner 1 can be improved. In addition, the structure of the communication pipes 991, 992, and 993 is extremely simple and can be manufactured at a very low cost.

  In the second embodiment, the communication pipe 990 is disposed at substantially the same distance from the distributor 11 of the refrigerant flow paths 30 and 40 (the refrigerant flow paths 31, 41, 51, 61, 71, and 81 have two refrigerants. 110), the heat transfer area of the heat exchanger can be used effectively.

  In the second embodiment, the communication pipe 991 (992/993) is provided in a place where the pressure difference between the refrigerant flow path 31 (51/71) and the refrigerant flow path 41 (61/81) becomes large. The liquid refrigerant moves between the refrigerant flow paths, and the difference in the refrigerant state between the refrigerant flow paths can be reduced.

  In the second embodiment, the communication pipe 992 (993) is connected to the outer peripheral surface (the outer surface of the bend) of the return bend 111C (111E) and the return bend 111D (111F) (see FIG. 6). However, the present invention is not limited to this, and the communication pipes 992 and 993 may be connected to positions corresponding to FIG.

(Third embodiment)
FIG. 12 is a side view showing a heat exchanger according to the third embodiment. In addition, FIG. 12 shows an example of a household indoor heat exchanger, the broken line in FIG. 12 shows the U-shaped tube portion of the heat transfer tube (corresponding to the heat transfer tube 110 in FIG. 2), Direction of refrigerant flow when the heat exchanger functions as an evaporator (cooling operation, ie, the direction of refrigerant flow when the indoor heat exchanger 3 functions as an evaporator and the outdoor heat exchanger 5 functions as a condenser) ). A pipe indicated by a thick solid line indicates a communication pipe 996 corresponding to the communication path in the claims.

  As shown in FIG. 12, the heat exchanger (evaporator) according to the third embodiment includes a main heat exchanger M, a subcooler A, a subcooler B, a two-way valve 7, distributors 931 and 951, and mergers 932 and 952. , 962, 972 are provided in a housing (not shown). In addition, the heat exchanger is arrange | positioned in the middle of the air path from the air inlet (not shown) provided in the housing | casing to a once-through type fan (not shown).

  In the heat exchanger according to the third embodiment, the refrigerant pipe 123 connected to the decompression device 4 (see FIG. 1) is connected to the heat transfer pipe opening end 201 of the subcooler A. The single flow path 23 from the heat transfer tube opening end 201 passes through the subcooler A, the refrigerant pipe 130 connecting the subcooler A and the subcooler B, and the subcooler B to reach the heat transfer tube opening end 206 at the outlet of the single flow path 23. . The heat transfer tube opening end 206 is connected to the distributor 931 through the refrigerant pipe 131.

  In the distributor 931, the refrigerant flow path is divided into two. One refrigerant flow path 33 reaches the merger 932 through the refrigerant pipe 132 connecting the distributor 931 and the heat transfer tube opening end 301 (one end), through the back side of the main heat exchanger M. The other refrigerant flow path 43 passes through the refrigerant pipe 133 connecting the distributor 931 and the heat transfer tube opening end 401 (one end), passes through the front side upper part and the back side of the main heat exchanger M, and enters the merger 932. It reaches the refrigerant flow path 33.

  After that, the refrigerant flow path where the refrigerant flow path 33 and the refrigerant flow path 43 merge is the refrigerant pipe 134, the two-way valve 7, the two-way valve 7, and the distributor 951 that connect the merger 932 and the two-way valve 7. After the refrigerant pipe 135 is connected, the distributor 951 divides it into four refrigerant flow paths 53, 63, 73 and 83.

  The two-way valve 7 is operated when the air conditioner 1 (see FIG. 1) is dehumidified, and has a throttling function (decompression function). During the dehumidifying operation, the refrigerant is not squeezed by the decompression device 4 (see FIG. 1), but is squeezed (depressurized) by the two-way valve 7 provided in the middle of the indoor heat exchanger 3 (see FIG. 1). Water in the air is removed by cooling the refrigerant with a heat exchanger downstream of the direction valve 7. At this time, in the indoor heat exchanger 3 (see FIG. 1), the air heated by the hot refrigerant passing through the heat exchanger upstream of the two-way valve 7 and the cold passing through the heat exchanger downstream of the two-way valve 7 The air cooled by the refrigerant is mixed and discharged outside the indoor heat exchanger 3 (see FIG. 1).

  The refrigerant flow path 53 passes through the refrigerant pipe 136 connecting the distributor 951 and the heat transfer pipe opening end 504, passes through the heat transfer pipes 581, 582, and 583 in the front side intermediate portion of the main heat exchanger M, and enters the merger 962. (The other end).

  The refrigerant flow path 63 passes through the refrigerant pipe 137 connecting the distributor 951 and the heat transfer pipe opening end 604, passes through the heat transfer pipes 681, 682, and 683 in the middle portion on the front side of the main heat exchanger M, and enters the merger 962. To join the refrigerant flow path 53.

  The refrigerant flow path 73 passes through the refrigerant pipe 138 connecting the distributor 951 and the heat transfer pipe opening end 703, passes through the heat transfer pipes 781, 782, 783 on the lower front side of the main heat exchanger M, and enters the merger 972 ( The other end).

  The refrigerant flow path 83 passes through the refrigerant pipe 139 connecting the distributor 951 and the heat transfer pipe opening end 804, passes through the heat transfer pipes 881, 882, 883 on the lowermost side of the front side of the main heat exchanger M, and enters the merger 972. And merges with the refrigerant flow path 73.

  After the refrigerant flow path 53 and the refrigerant flow path 63 merge in the merger 962 and the refrigerant flow path 73 and the refrigerant flow path 83 merge in the merger 972, the merger is further connected via the refrigerant pipe 151 and the refrigerant pipe 152. After a single refrigerant flow path 952, the refrigerant pipe 124 is reached and the compressor 2 (see FIG. 1) is reached. The refrigerant channel 53 and the refrigerant channel 63 are divided vertically in the vertical direction, and the refrigerant channel 73 and the refrigerant channel 83 are divided vertically in the vertical direction.

  In the third embodiment, in the middle of the refrigerant flow path 53, the refrigerant flow path 63, the refrigerant flow path 73, and the refrigerant flow path 83, the return bend 111M that connects the heat transfer pipe 581 and the heat transfer pipe 582, the heat transfer pipe 681, and the heat transfer pipe 681. A return bend 111N that connects the heat pipe 682, a return bend 111O that connects the heat transfer pipe 781 and the heat transfer pipe 782, and a return bend 111P that connects the heat transfer pipe 881 and the heat transfer pipe 882 are connected by a communication pipe 996. Yes. The communication pipe 996 is connected to the outer peripheral surface 111b of the bent pipe 111a of the return bends 111M, 111N, 111O, and 111P (see FIG. 6).

  Thereby, in the refrigerant flow path after the communication pipe 996, the difference in the degree of evaporation of the refrigerant existing between the refrigerant flow path 53, the refrigerant flow path 63, the refrigerant flow path 73, and the refrigerant flow path 83 is reduced. The original heat exchange capability of the evaporator can be exhibited, and the performance of the air conditioner 1 can be improved.

(Fourth embodiment)
FIG. 13 is a side view showing a heat exchanger according to the fourth embodiment. In the fourth embodiment, communication pipes 997, 998, and 999 are used instead of the communication pipe 996 of the third embodiment, and the same components as those in the third embodiment are denoted by the same reference numerals and duplicated. Description is omitted. The communication pipes 997, 998, and 999 correspond to the communication paths in the claims.

  As shown in FIG. 13, the heat exchanger (evaporator) according to the fourth embodiment includes a return bend 111 </ b> M that connects the heat transfer pipe 581 and the heat transfer pipe 582 in the middle of the refrigerant flow path 53 and the refrigerant flow path 63. , A communication pipe 997 connecting the return bend 111N connecting the heat transfer pipe 681 and the heat transfer pipe 682, and a return bend connecting the heat transfer pipe 781 and the heat transfer pipe 782 in the middle of the refrigerant flow path 73 and the refrigerant flow path 83. The heat transfer tube 682 and the heat transfer tube 683 are connected in the middle of the communication pipe 998 that connects the return bend 111P that connects 111O and the heat transfer tube 881 and the heat transfer tube 882, and the refrigerant flow channel 63 and the refrigerant flow channel 73. A communication pipe 999 is provided for connecting the return bend 111Q and the return bend 111R that connects the heat transfer pipe 782 and the heat transfer pipe 783.

  The communication pipes 997, 998, and 999 all have an outer peripheral surface (an outer peripheral surface, an outer surface of the bend) 111b (FIG. 6) of the bent pipe 111a of the return bends 111M, 111N, 111O, 111P, 111Q, and 111R. See).

  Thereby, the change in the refrigerant state is almost the same in the refrigerant flow path 53, the refrigerant flow path 63, the refrigerant flow path 73, and the refrigerant flow path 83 by the communication pipe 997, the communication pipe 998, and the communication pipe 999. The heat exchange performance as an evaporator can be improved, and the performance improvement as the air conditioner 1 can be aimed at.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in each embodiment, a plurality of first to fourth installation methods may be selected and applied as a method for connecting the communication pipes.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Compressor 3 Indoor heat exchanger 4 Pressure reducing device 5 Outdoor heat exchanger 6 Four way valve 30, 31, 40, 41, 51, 53, 61, 63, 71, 73, 81, 83 Refrigerant flow path 100 Fin 110 U-shaped heat transfer tube (heat transfer flow path)
111a, 142a, 143a bent pipe (bent flow path)
111b, 111d, 142b, 143b Outer peripheral surface (surface on the outer peripheral side)
110e Bottom 111, 111A, 111B, 111C, 111D, 111E, 111F, 111M, 111N, 111O, 111P, 111Q, 111R, 142, 143 Return bend 11, 933, 951, 953, 973 Distributor 12, 934, 952, 954,974 Combiner 990,991,992,993,996,997,998,999 Communication pipe (communication path)

Claims (5)

A compressor for compressing the refrigerant;
A condenser for condensing the refrigerant compressed by the compressor;
A decompression device for decompressing the refrigerant condensed in the condenser;
An evaporator for evaporating the refrigerant decompressed by the decompression device;
Comprising at least
The evaporator is
A plurality of refrigerant flow paths at least partially divided vertically in the vertical direction;
A distributor for diverting a refrigerant to the plurality of refrigerant channels at one of both ends of the plurality of refrigerant channels;
A merger for merging the refrigerant flowing through the plurality of refrigerant channels to the other of the two ends of the plurality of refrigerant channels;
A communication path for communicating the plurality of refrigerant flow paths,
The refrigerant flow path has a heat transfer flow path that extends in the horizontal direction and performs heat exchange, and a bent flow path that returns from the heat transfer flow path to the other heat transfer flow path,
The air conditioner characterized in that the communication path communicates with a surface on an outer peripheral side of the bent flow path in the middle of the refrigerant flow path. A compressor for compressing the refrigerant;
A condenser for condensing the refrigerant compressed by the compressor;
A decompression device for decompressing the refrigerant condensed in the condenser;
An evaporator for evaporating the refrigerant decompressed by the decompression device;
Comprising at least
The evaporator is
A plurality of refrigerant flow paths at least partially divided vertically in the vertical direction;
A distributor for diverting a refrigerant to the plurality of refrigerant channels at one of both ends of the plurality of refrigerant channels;
A merger for merging the refrigerant flowing through the plurality of refrigerant channels to the other of the two ends of the plurality of refrigerant channels;
A communication path for communicating the plurality of refrigerant flow paths,
The refrigerant flow path has a heat transfer flow path that extends in the horizontal direction and performs heat exchange, and a bent flow path that returns from the heat transfer flow path to the other heat transfer flow path,
The air conditioner characterized in that the communication path communicates with a surface on the outer peripheral side immediately after the refrigerant downstream side of the bent flow path in the middle of the refrigerant flow path. The air conditioner according to claim 1 or 2 , wherein the communication path is located at substantially the same distance from the distributor of the refrigerant flow path. The air conditioner according to claim 1 or 2 , wherein the communication path is provided between refrigerant channels having different heights. The air conditioner according to claim 1 or 2 , wherein the communication path is provided at a position where a pressure difference between the refrigerant flow paths becomes large.

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