JP2012052676A - Heat exchanger and air conditioner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger with high efficiency, in which condensation performance and evaporation performance of the heat exchanger are improved while suppressing an increase in draft resistance.SOLUTION: The heat exchanger includes a first heat exchanger and a second heat exchanger, each having a plurality of plate-like fins arranged in the direction of the plate thickness and heat conduction pipes in a plurality of stages penetrating the plate-like fins and disposed in a longitudinal direction of the plate-like fins. The heat exchanger exchanges heat between air and a refrigerant by circulating the refrigerant in the heat conduction pipes and supplying air in a perpendicular direction with respect to the plate thickness direction of the plate-like fins. The first heat exchanger is located in a windward side of the second heat exchanger. Each of the plate-like fins of the first heat exchanger and the second exchanger has a chevron shape in the longitudinal direction, formed such that the chevron shape formed in the plate-like fins of the first heat exchanger is lower than the chevron shape formed in the plate-like fins of the second heat exchanger. The pipe diameter of the heat conduction pipes in the first heat exchanger is smaller than the pipe diameter of the heat conduction pipes in the second heat exchanger.

Description

  The present invention relates to a heat exchanger and an air conditioner using the heat exchanger.

  In the conventional air conditioner, in order to improve the heat exchange efficiency in the heat exchanger, the windward diameter of the heat transfer tube constituting the heat exchanger is made smaller than the leeward pipe diameter (the pipe diameter is reduced). By reducing the size, the heat transfer coefficient inside the tube when used as a condenser is improved (for example, see Patent Document 1).

  Moreover, in order to improve the air-side heat transfer coefficient and increase the heat transfer area, some plate-like fins constituting the heat exchanger have a chevron shape or a cut-and-raised shape. However, when using a heat exchanger as an evaporator, the air flow path in a plate-shaped fin is obstruct | occluded by frost formation, and the performance of a heat exchanger falls remarkably. In this way, the chevron shape formed on the plate-like fins, the cut-and-raised portion, etc., increases the ventilation resistance compared to the case where the chevron-shaped shape and the raised portions are not formed, and the evaporation temperature decreases, leading to the heat exchanger. Will promote frosting.

  For this reason, while forming a peak part in each row | line | column of the plate-shaped fin which comprises a heat exchanger, and making the peak part of both ends lower than the height of a center peak part, the heat-transfer performance by a peak part is improved. While obtaining the improvement effect, an increase in ventilation resistance that is a factor of frost formation is suppressed (for example, see Patent Document 2).

  However, since the heat exchangers described in Patent Documents 1 and 2 are not configured in consideration of both the fins and the heat transfer tubes constituting the heat exchanger, the performance of the heat exchanger is not necessarily maximized.

JP-A-11-257800 Japanese Patent Laid-Open No. 2008-128569

  It is an object of the present invention to provide a highly efficient heat exchanger that improves the condensation performance and evaporation performance of a heat exchanger while suppressing an increase in ventilation resistance, and an air conditioner using this heat exchanger. And

  The heat exchanger of the present invention includes a first fin having a plurality of plate-like fins arranged in the plate thickness direction and a plurality of heat transfer tubes that penetrate the plate-like fin and are provided in a plurality of stages in the longitudinal direction of the plate-like fin. The heat exchanger includes a exchanger and a second heat exchanger, and causes the refrigerant to flow inside the heat transfer tubes and blows air in a direction perpendicular to the plate thickness direction of the plate fins to exchange heat between the air and the refrigerant. The first heat exchanger is located on the windward side of the second heat exchanger, and the plate-like fins of the first heat exchanger and the second heat exchanger each have a chevron shape in the longitudinal direction, and the second heat exchange The height of the chevron formed on the plate-shaped fin of the first heat exchanger is lower than the height of the chevron formed on the plate-shaped fin of the heat exchanger, and the tube diameter of the heat transfer tube of the second heat exchanger Rather, the tube diameter of the heat transfer tube of the first heat exchanger is formed smaller.

  According to the present invention, it is possible to provide a highly efficient heat exchanger that improves the condensation performance and evaporation performance of a heat exchanger while suppressing an increase in ventilation resistance, and an air conditioner using this heat exchanger. Can do.

The block diagram showing each component which comprises an air conditioning apparatus, and those connection relations. The perspective view which shows the basic composition of a heat exchanger. The side view which shows the shape of the plate-shaped fin of a heat exchanger. Sectional drawing which shows the shape of the plate-shaped fin of a heat exchanger. The figure which shows the refrigerant | coolant path | route of a heat exchanger. The figure which shows the relationship of the refrigerant | coolant dryness in the refrigerant | coolant path | route part of the outdoor heat exchanger at the time of heating operation, the local exchange heat amount, and the refrigerant | coolant side pressure in the route figure of the whole refrigerating cycle. The figure which shows the relationship of the refrigerant | coolant dryness in the refrigerant | coolant path | route part of the whole refrigerating cycle, the refrigerant | coolant path | route part of the outdoor heat exchanger at the time of air_conditionaing | cooling operation, and local exchange amount of heat. The side view which shows the shape of the plate-shaped fin of a heat exchanger. Sectional drawing which shows the shape of the plate-shaped fin of a heat exchanger. The side view which shows the shape of the plate-shaped fin of a heat exchanger. Sectional drawing which shows the shape of the plate-shaped fin of a heat exchanger.

  A first embodiment according to the present invention will be described below with reference to the drawings. First, the configuration, function, and operation of the heat exchanger of the present embodiment will be described with reference to FIGS. 1-7. FIG. 1 is a configuration diagram showing each component constituting the air-conditioning apparatus according to the present embodiment and their connection relationship. FIG. 2 is a perspective view showing a basic configuration of the heat exchanger shown in FIG. FIG. 3 is a side view showing the shape of the plate-like fins of the heat exchanger shown in FIG. FIG. 4 is a cross-sectional view showing the shape of the plate-like fins of the heat exchanger shown in FIG. FIG. 5 is a diagram illustrating an example of a refrigerant path of the heat exchanger illustrated in FIG. 2.

  As shown in FIG. 1, the air conditioner includes a compressor 1, a flow path switching means (four-way valve) 2, an outdoor heat exchanger 3, a cooling / heating expansion device (flow control valve) 4, and an indoor heat exchanger 5. Are connected in an annular shape through a refrigerant pipe to constitute a refrigeration cycle capable of cooling and heating. The outdoor heat exchanger 3 is provided with an outdoor air blowing means 6 such as a propeller fan, and heat is exchanged with the refrigerant by circulating air through the outdoor heat exchanger 3. The indoor heat exchanger 5 is provided with indoor air blowing means 7 such as a cross-flow fan, and heat is exchanged with the refrigerant by circulating air through the indoor heat exchanger 5.

  As shown in FIG. 2, the outdoor heat exchanger 3 and the indoor heat exchanger 5 include a plurality of plate-like fins 8 arranged in parallel at regular intervals in the plate thickness direction, and plate-like fins that penetrate the plate-like fins 8. 8 and heat transfer tubes 9 provided in a plurality of stages in the longitudinal direction, and these are provided in a plurality of rows in the air flow direction 100 (in FIG. 2, two stages are provided for the air flow direction 100. Although the heat exchanger 3 or the indoor heat exchanger 5 is comprised, in a present Example, let the windward side be the 1st heat exchanger A and the leeward side be the 2nd heat exchanger B for convenience. In the outdoor heat exchanger 3 and the indoor heat exchanger 5 configured as described above, air flows by flowing a refrigerant in the heat transfer tube 9 and blowing air in a direction perpendicular to the plate thickness direction of the plate fins 8. Heat exchange with the refrigerant. Here, in this embodiment, the vertical direction in FIG. 2 (vertical direction in FIG. 3) is the longitudinal direction of the plate-like fin 8, and the depth direction in FIG. 2 (horizontal direction in FIG. 3) is the width direction of the plate-like fin 8. 2 is defined as the plate thickness direction of the plate-like fin 8. The plate-like fins 8 are aluminum alloy thin plates (for example, a thickness of 0.1 mm), and the heat transfer tubes 9 are copper tubes.

  As shown in FIG. 3, the plate-like fins 8 of the outdoor heat exchanger 3 are provided with two rows of through holes of the heat transfer tubes 9 at a predetermined row pitch S2 (for example, S2 = 17 mm) in the width direction. The center of the through hole is located at an equal distance from the left and right end surfaces of the plate-like fin 8. In the longitudinal direction of the plate-like fin 8, a plurality of through holes of the heat transfer tube 9 are provided at a predetermined step pitch S1 or S1 ′ (for example, S1 = S1 ′ = 20 mm). The through holes in adjacent rows are arranged in a staggered arrangement with each other. The diameter D2 of the through hole of the heat transfer tube 9 of the first heat exchanger that is upstream of the air flow direction 100 is larger than the diameter D1 of the through hole of the heat transfer tube 9 of the second heat exchanger B that is downstream of the air flow direction 100. Is set to a small diameter (for example, D1 = 8 mm, D2 = 7 mm). The reason why the diameter D2 of the first heat exchanger is set smaller than the diameter D1 of the second heat exchanger B will be described later.

  FIG. 4 shows an XX cross section of FIG. The plate-like fin 8 is formed with a chevron shape (in this embodiment, four chevron shapes in each row of 10A to 10D and 11A to 11D) in the row direction (longitudinal direction) for each row.

The height h ₁₀ of the chevron shape 10A~10D of the first heat exchanger A is the upstream side in the air flow direction column, than the height h ₁₁ of the chevron shape 11A~11D of the second heat exchanger B is a downstream column It is formed low (for example, h10 = 0.5 mm, h11 = 0.8 mm). The reason why the chevron-shaped height h ₁₀ of the first heat exchanger A is formed lower than the chevron-shaped height h ₁₁ of the second heat exchanger B will be described later.

  FIG. 5 is a diagram showing the configuration of the refrigerant path of the heat exchanger. The refrigerant path is composed of four paths from the top to 12A to 12D and two paths of 13A and 13B. The upper four paths branch from one path to four in the windward line. The uppermost two paths 12A and 12B join in a leeward row and connect to the lower path 13A. The middle two paths 12C and 12D join in a leeward row and connect to the lower path 13B. Lower paths 13A and 13B merge into one path in a leeward row. As shown in FIG. 5, when the heat exchanger functions as an evaporator, the number of passes of the heat transfer tube increases toward the downstream side in the flow direction of the refrigerant, and when the heat exchanger functions as a condenser, The number of passes decreases toward the downstream in the refrigerant flow direction. Moreover, all the inlet parts of the refrigerant in the heat exchanger when the heat exchanger functions as a condenser (the outlet part of the refrigerant in the heat exchanger when the heat exchanger functions as an evaporator) Located in the heat exchanger (second heat exchanger B).

  Next, operation | movement of the refrigerating cycle of the air conditioning apparatus in a present Example is demonstrated. In FIG. 1, during heating operation, the flow path switching means (four-way valve) 2 is switched so that the refrigerant flows in the direction of the solid line. At this time, the refrigerant proceeds in the direction of the solid arrow in FIG. 1 (clockwise direction in FIG. 1), and compressor 1, flow path switching means (four-way valve) 2, indoor heat exchanger 5, flow control valve 4, outdoor heat. It flows in the order of the exchanger 3. The flow control valve 4 is adjusted to an appropriate opening according to the air conditioning load, and the refrigerant condensed and liquefied by the indoor heat exchanger 5 functioning as a condenser becomes a gas-liquid two-phase flow at the flow control valve 4, It flows into the outdoor heat exchanger 3. Thereafter, the refrigerant evaporates in the outdoor heat exchanger 3 that functions as an evaporator, and then returns to the compressor 1.

  In such a refrigeration cycle of an air conditioner, a phenomenon in the outdoor heat exchanger 3 will be described. Air is blown to the outdoor heat exchanger 3 by the outdoor blowing means 6 shown in FIG. Specifically, as shown in FIG. 3, air flows into the heat exchanger in the direction of the air flow direction 100, and the air is blown from the first heat exchanger A so as to pass through the second heat exchanger. The refrigerant and air flowing through the heat transfer tube exchange heat.

  Here, a plurality of chevron shapes are formed on each plate-like fin 8 of the first heat exchanger A and the second heat exchanger B, and the air flow is disturbed by these chevron shapes to promote heat transfer. However, the higher the chevron shape, the higher the local heat transfer coefficient and the better the heat transfer performance, but the ventilation resistance increases and the power of the outdoor air blowing means 6 increases. Further, at the same step pitch, the smaller the diameter of the heat transfer tube, the lower the ventilation resistance and the air side heat transfer area, but the heat transfer area in the heat transfer tube decreases. Thus, the height of the chevron formed in the plate-like fin 8 and the size of the diameter of the heat transfer tube passing through the plate-like fin generally have a trade-off relationship between heat transfer performance and ventilation resistance. Exists.

  Here, in the outdoor heat exchanger 3, the windward row (first heat exchanger A) is easy to ensure the temperature difference between the air and the refrigerant, so that the heat transfer rate is relatively high and the heat transfer rate on the air side is high. It is advantageous to give priority to the reduction of draft resistance over improvement. On the other hand, in the leeward row (second heat exchanger B), air exchanged in the windward row flows in compared to the windward row, so it is difficult to secure a temperature difference between the air and the refrigerant. It is advantageous to prioritize rates. Therefore, in this embodiment, in the leeward row (first heat exchanger A), priority is given to improving the air-side heat transfer coefficient, the height of the mountain shape is increased, the diameter of the heat transfer tube is increased, and the windward row is increased. In the (second heat exchanger B), the reduction in ventilation resistance is prioritized, and the height of the chevron is reduced with respect to the leeward row, and the heat transfer tube diameter is reduced.

  So far, the phenomenon on the air side in the heat exchanger has been described, but the phenomenon on the refrigerant side will be described below. FIG. 6 is a route diagram of the entire refrigeration cycle, refrigerant dryness χ distribution, local exchange heat quantity q distribution, and refrigerant side pressure distribution Pe in the refrigerant path portion of the outdoor heat exchanger 3 for the outdoor heat exchanger 3 of FIG. Show the relationship. The refrigerant path has the refrigerant path configuration shown in FIG. 5 as an example. The dryness χ is a value obtained by dividing the refrigerant gas mass flow rate by the refrigerant total mass flow rate, and is dryness χ≡refrigerant gas mass flow rate / refrigerant total mass flow rate (χ = 1: complete refrigerant gas, χ = 0: complete Refrigerant liquid). The local exchange heat quantity q is the exchange heat quantity when air and the refrigerant exchange heat in a certain part of the heat exchanger (for example, one stage of refrigerant piping).

  In FIG. 6, the solid line indicates that the height of the mountain shape of the leeward row (second heat exchanger B) is high and the heat transfer tube diameter is increased, and the leeward row (first heat exchanger) This is a case where the height of the mountain shape of A) is low and the diameter of the heat transfer tube is small. A broken line is a case where the fin height is uniform (uniformly low) and the heat transfer tube diameter is uniform. The refrigerant flows in the direction of the solid arrow. The dryness χ in the refrigerant path portion changes from the right side to the left side of the graph.

  In the refrigerant path as in this embodiment, when the outdoor heat exchanger 3 functions as an evaporator, the refrigerant flow in each refrigerant path is parallel to the air, and the temperature on the refrigerant side increases from the windward to the leeward. Therefore, the temperature difference between the air and the refrigerant can be ensured to the maximum.

  The refrigerant that has passed through the flow control valve 4 flows into the outdoor heat exchanger 3 in a gas-liquid two-phase state. At this time, the dryness is low at the heat exchanger inlet, and the dryness increases as heat is exchanged with air. At the outlets of the four-branched refrigerant paths 12A to 12D, the refrigerant is completely gas with a dryness χ = 1.

  On the other hand, the local exchange heat quantity q is the largest on the windward side of the inlet refrigerant paths 13A and 13B, both in the solid line and the broken line. This is because the temperature difference between the refrigerant and air is large on the air side, and on the refrigerant side, there are two paths on the upstream side of the refrigerant paths 13A and 13B on the inlet side with respect to the four paths on the downstream side. This is because the heat pipe diameter is small and the cross-sectional area is small, so that the refrigerant flow rate is twice or more that of the downstream side, and the heat transfer coefficient of the refrigerant is increased.

  At the outlets of the refrigerant paths 13A and 13B, since the temperature difference between the air and the refrigerant cannot be obtained in the leeward line in both the solid line and the broken line, the exchange heat amount is reduced. However, the decrease in the exchange heat amount of the solid line is small compared to the broken line. This is because, in the solid line, the air side heat transfer coefficient of the leeward row is high, so that heat is efficiently exchanged even with a small temperature difference between the air and the refrigerant. Similarly, in the four paths 12A to 12D, the amount of exchange heat decreases as the refrigerant gasifies. However, in the solid line, since the air side heat transfer coefficient of the leeward row is high and the efficiency of heat exchange is high, there is little decrease in the amount of exchange heat.

  In addition, the refrigerant pressure distribution is such that both the solid line and the broken line, the pressure drops more slowly in 12A to 12D of the four paths than in the two paths of 13A and 13B, and the pressure loss increases in the two-phase area than in the single-phase area. However, the flow loss per path decreases due to the increase of the path, and the pressure loss decreases. Further, in the solid line, the heat transfer tube diameter increases on the leeward side of the two paths and the leeward side of the four paths, and the pressure loss can be reduced by increasing the path cross-sectional area in the two-phase region where the pressure loss is large. The decline of the At this time, the decrease in the refrigerant-side heat transfer coefficient due to the decrease in the refrigerant flow velocity due to the increase in the path cross-sectional area is offset because the air-side heat transfer coefficient on the plate-like fin side 8 is high. In this way, by reducing the pressure drop due to the pressure loss of the refrigerant being evaporated, the evaporation pressure rises with the same amount of exchange heat, and the pressure ratio with the condensation side can be reduced, so the compression power decreases.

  Further, even under conditions where frost formation occurs on the air side, the ventilation resistance of the upwind row is less than that of the downwind row, and frosting starts from the downwind row. For this reason, compared with the case where frosting starts from the windward row, the time until the flow path blockage between the plate fins 8 becomes longer, the operation time can be extended even under frosting conditions, and highly efficient and comfortable air conditioning. realizable.

  Next, in the air conditioning apparatus of FIG. 1, during the cooling operation, the flow path switching means (four-way valve) 2 is switched so that the refrigerant flows in the direction of the broken line arrow in FIG. 1. At this time, the refrigerant is in the direction of the broken line arrow in FIG. 1 (counterclockwise direction in FIG. 1), compressor 1, flow path switching means (four-way valve) 2, outdoor heat exchanger 3 functioning as a condenser, and flow control. It flows in the order of the valve 4 and the indoor heat exchanger 5 that functions as an evaporator. The flow rate control valve 4 is adjusted to an appropriate opening degree corresponding to the air conditioning load, and the refrigerant condensed and liquefied by the outdoor heat exchanger 3 is decompressed and expanded by the flow rate control valve 4 and is then transferred to the indoor heat exchanger 5 of the evaporator. It evaporates and returns to the compressor 1.

  In such a refrigeration cycle of an air conditioner, a phenomenon in the outdoor heat exchanger 3 will be described. Air is blown to the outdoor heat exchanger 3 by the outdoor blowing means 6 shown in FIG. In FIG. 3, the air flows into the heat exchanger in the direction of the air flow direction 100. Specifically, as shown in FIG. 3, air flows into the heat exchanger in the direction of the air flow direction 100, and the air is blown from the first heat exchanger A so as to pass through the second heat exchanger. As a result, the refrigerant and air flowing inside the heat transfer tubes exchange heat. Here, since the phenomenon only on the air side in the plate-like fins 8 is the same as that in the heating operation, the description thereof will be omitted, and the phenomenon including the refrigerant side will be described below.

  FIG. 7 shows the relationship between the route diagram of the entire refrigeration cycle, the refrigerant dryness χ distribution in the refrigerant path portion of the outdoor heat exchanger 3, and the local exchange heat quantity q distribution for the outdoor heat exchanger 3 in FIG. The refrigerant path has the refrigerant path configuration shown in FIG. 5 as an example.

  In FIG. 7, the solid line indicates that the height of the mountain shape of the leeward row (second heat exchanger B) is high and the heat transfer tube diameter is increased, and the leeward row (first heat exchanger A) ) In the case where the height of the chevron shape is low and the diameter of the heat transfer tube is small. A broken line is a case where the fin height is uniform (uniformly low) and the heat transfer tube diameter is uniform. The refrigerant flows in the direction of the dashed arrow. The dryness χ in the refrigerant path portion changes from the left to the right of the graph.

  In the refrigerant path as in this embodiment, when the outdoor heat exchanger 3 functions as condensing, the refrigerant flow in each refrigerant path is opposite to air, and the temperature on the refrigerant side increases from the windward to the leeward. Therefore, the temperature difference between the air and the refrigerant can be ensured to the maximum.

  The refrigerant that has passed through the flow path switching means (four-way valve) 2 flows into the outdoor heat exchanger 3 as a high-temperature and high-pressure gas refrigerant. At this time, the gas at the inlet of the heat exchanger is a complete gas with a dryness χ = 1, and the dryness decreases as heat is exchanged with air. From the vicinity of the inlets of the two branched refrigerant paths 13A and 13B to the outlet, the refrigerant is completely liquid at a dryness χ = 0. Thus, the gas region to the two-phase region are reduced to four branches, and the liquid region is reduced to two branches. This is because the refrigerant-side heat transfer coefficient is lower in the liquid region than in the two-phase region, and the refrigerant-side heat transfer coefficient is improved by increasing the flow velocity by reducing the flow path cross-sectional area.

  On the other hand, regarding the local exchange heat quantity q distribution, at the inlet of the heat exchanger, there are four refrigerant paths, the refrigerant flow rate is slow, and the dryness is high, so the exchange heat quantity is low. However, the decrease in the exchange heat amount of the solid line is small compared to the broken line. This is because, in the solid line, the air-side heat transfer coefficient of the leeward row is high, and heat is efficiently exchanged even with a small temperature difference between the air and the refrigerant. At this time, the gas content (dryness χ = 1) at the refrigerant path inlet changes to two phases (dryness χ <1) earlier than the broken line, and the two-phase region having a high refrigerant side heat transfer coefficient is expanded. In the subsequent two paths 13A and 13B, the refrigerant liquefies and the amount of exchange heat decreases. However, in the solid line, the air side heat transfer coefficient of the leeward row is high, the heat exchange efficiency is high, and the flow rate of the refrigerant flowing in the liquid increases because the heat transfer tube diameter of the windward row is small, and the exchange heat quantity There is little decrease.

  In this example, the height of the fins was uniformly low and compared with the case where the heat transfer tube diameter was uniform, but the height of the fins was uniformly increased and the heat transfer coefficient on the air side was given the highest priority. In this case, the exchange heat amount increases, but since the same air amount is produced, the fan power increases and the overall efficiency decreases.

  As described above, the heat exchanger of the present embodiment includes a plurality of plate-like fins arranged in the plate thickness direction, a heat transfer tube provided in a plurality of stages in the longitudinal direction of the plate-like fins through the plate-like fins, and The first heat exchanger and the second heat exchanger each having a flow rate are provided, the refrigerant flows inside the heat transfer tube, and the air and the refrigerant are heat-exchanged by blowing in a direction perpendicular to the plate thickness direction of the plate-like fins. The first heat exchanger is located on the windward side of the second heat exchanger, and the plate-like fins of the first heat exchanger and the second heat exchanger each have a chevron shape in the longitudinal direction. And the height of the chevron formed in the plate fin of the first heat exchanger is lower than the height of the chevron formed in the plate fin of the second heat exchanger, and the second heat exchanger The tube diameter of the heat transfer tube of the first heat exchanger is formed smaller than the tube diameter of the heat transfer tube. Therefore, it is possible to provide a highly efficient heat exchanger that improves the condensation performance and evaporation performance of the heat exchanger while suppressing an increase in ventilation resistance.

  In particular, when the heat exchanger functions as an evaporator, the number of heat transfer tube paths increases toward the downstream side of the refrigerant flow direction, and the refrigerant flow direction and the air flow direction become parallel flows, thereby exchanging heat. When the condenser functions as a condenser, the number of paths of the heat transfer tubes decreases toward the downstream side in the refrigerant flow direction, and the refrigerant flow direction and the air flow direction are counterflows. In such a heat exchanger, as described above, regardless of whether the heat exchanger functions as a condenser or an evaporator, the heat exchange performance can be improved while suppressing an increase in ventilation resistance.

  In addition, since the heat exchanger of the present embodiment has high efficiency of heat exchange for both condensation and evaporation and can reduce pressure loss during evaporation, not only a high-density refrigerant (for example, HFC410a) having a high evaporation pressure, Efficient operation is possible even when a low-density refrigerant (for example, HFC134a, HFO1234yf, etc.) with a low evaporation pressure is used. In the present embodiment, the case of the combination of the four paths and the two paths has been described. In particular, when a low-density refrigerant having a low evaporation pressure (for example, HFC134a, HFO1234yf, etc.) is used, the pressure loss is further reduced. In order to maintain the condensation performance, for example, a combination of 8 paths and 4 paths may be used.

  In this embodiment, the outdoor heat exchanger is mainly the subject of the present invention, but the same effect can be obtained even if the present invention is applied to the indoor heat exchanger.

  In the present embodiment, the heights of the chevron shapes of the first heat exchanger and the second heat exchanger are the average heights of the chevron shapes of the first heat exchanger and the second heat exchanger, respectively. Therefore, for example, regarding the influence of the ventilation resistance due to the mountain shape, the ventilation resistance of the entire first heat exchanger is smaller than the ventilation resistance of the entire second heat exchanger.

  Next, a second embodiment according to the present invention will be described with reference to FIGS. In this example, (1) the basic components showing the components constituting the air conditioner and their connection relationship, (2) the basic configuration of the heat exchanger, (3) the refrigerant path of the heat exchanger, etc. Since it is the same as that of the first embodiment, its description is omitted.

  FIG. 8 is a side view showing the shape of the plate-like fins of the heat exchanger of this embodiment, and FIG. 9 is a cross-sectional view showing the shape of the plate-like fins of the heat exchanger of this embodiment. In this embodiment, the plate-like fins 8 'of the outdoor heat exchanger 3 are provided with two rows of through-holes of the heat transfer tubes 9 at a predetermined row pitch S2 (for example, S2 = 17 mm) in the fin width direction as shown in FIG. It is done. The center of the through hole is located at the center in the fin width direction of the plate-like fin 8 '. Further, a plurality of through holes of the heat transfer tube 9 are provided in the longitudinal direction of the plate-like fins 8 ′ at a predetermined step pitch S1 or S1 ′ (for example, S1 = S1 ′ = 20 mm) in the vertical direction. The through holes in adjacent rows are arranged in a staggered arrangement with each other. The diameter D2 of the through hole of the heat transfer tube 9 on the upstream side (first heat exchanger A) is set smaller than the diameter D1 of the through hole of the heat transfer tube 9 on the downstream side (second heat exchanger B) in the air flow direction 100. (For example, D1 = 8 mm, D2 = 7 mm).

  FIG. 9 shows a YY cross section of FIG. A plurality of chevron shapes (four rows 20A to 20D and four rows 21A to 21D in the present embodiment) are formed in the row direction on the plate-like fins 8 'in the row direction. The height of the chevron shape in the same row (the first heat exchanger A or the second heat exchanger B) is greater than the chevron shapes 20A, 20D and 21A, 21D provided at both ends in each row. The chevron shapes 20B, 20C and 21B, 21C close to the through-holes are formed high. Further, the height of any chevron in the upstream (first heat exchanger A) row in the air flow direction 100 is formed lower than the height of the lowest chevron shapes 21A and 21D in the downstream (second heat exchanger B) row. (For example, h20A = h20D = 0.3 mm, h20B = h20C = 0.5 mm, h21A = h21D = 0.6 mm, h21B = h21C = 0.8 mm). With such a configuration, the height of the chevron shape that is close to the heat transfer tube and high heat exchange efficiency is increased to improve the heat exchange efficiency, and the height of the chevron shape that is far from the heat transfer tube and has low heat exchange efficiency is lowered. By reducing the ventilation resistance, a highly efficient heat exchanger can be configured while reducing the ventilation resistance in each of the first heat exchanger and the second heat exchanger.

  As described above, in the heat exchanger in the present embodiment, the plate-like fins of the first heat exchanger and the second heat exchanger each have a plurality of chevron shapes in the longitudinal direction, and the fins of the plurality of chevron shapes The height of both end chevron shapes located at both ends in the width direction is formed lower than the height of the central chevron shape located on the heat transfer tube side than both end chevron shapes. In each of the two heat exchangers, a highly efficient heat exchanger can be configured while further reducing the ventilation resistance.

  Next, a third embodiment according to the present invention will be described with reference to FIGS. In this example, (1) the basic components showing the components constituting the air conditioner and their connection relationship, (2) the basic configuration of the heat exchanger, (3) the refrigerant path of the heat exchanger, etc. Since it is the same as that of the first embodiment, its description is omitted.

  FIG. 10 is a side view showing the shape of the plate fins of the heat exchanger of the present embodiment, and FIG. 11 is a cross-sectional view showing the shape of the plate fins of the heat exchanger of the present embodiment. In this embodiment, the plate-like fins 8 ″ of the outdoor heat exchanger 3 are provided with two rows of through holes of the heat transfer tubes 9 at a predetermined row pitch S2 (for example, S2 = 17 mm) in the fin width direction as shown in FIG. It is done.

  The through hole is located on the leeward side of the fin-width-direction center of the plate-like fin 8 ″ (that is, the length from the through hole to the leeward end is longer than the length from the through hole to the leeward end). The through-holes are positioned so that, for example, W1 = 10 mm> W2 = 7 mm) In the vertical direction, the through-holes of the heat transfer tube 9 are arranged at a predetermined step pitch S1 or S1 ′ (for example, S1 = S1 ′ = 20 mm). A plurality of stages are provided in the longitudinal direction of the plate-like fins 8 ″. In addition to the low wind resistance of the windward row relative to the leeward row, the distance from the heat transfer tube to the windward end of the plate-like fin 8 ″ in the same row is longer than the distance to the windward end. Since they are separated from each other, it is possible to lengthen the time until the flow path is blocked by the plate-like fins 8 ″ due to frost formation.

  Similar to the first embodiment, the through holes in adjacent rows are arranged in a staggered manner. The diameter D2 of the through hole of the heat transfer tube 9 on the upstream side (first heat exchanger A) is smaller than the diameter D1 of the through hole of the heat transfer tube 9 on the downstream side (second heat exchanger B) in the air flow direction 100 (for example, D1 = 8 mm, D2 = 7 mm).

  FIG. 11 shows a ZZ cross section of FIG. A plurality of chevron shapes (three rows 20A to 20C and three rows 21A to 21C in the present embodiment) are formed in the row direction for each row in the plate-like fin 8 ″. The same row (first heat exchange) The height of the chevron shape in the heat exchanger A or the second heat exchanger B) is greater in the through hole of the heat transfer tube 9 than the chevron shapes 20A and 21A provided at the upstream end of the air flow direction 100 in each row. The closest chevron shapes 20B, 20C and 21B, 21C are formed higher, and the chevron shape height of the upstream row in the air flow direction can be made lower than the height of the highest chevron shape 21A than on the downstream side. (For example, h20A = 0.3 mm, h20B = h20C = 0.5 mm, h21A = 0.6 mm, h21B = h21C = 0.8 mm) With this configuration, as in the second embodiment, the heat transfer tube Mountain shape with high heat exchange efficiency (20B, Increase the height of 0C and 21B, 21C) to improve the heat exchange efficiency, and reduce the height of the chevron shape (20A and 21A) that is far from the heat transfer tube and has a low heat exchange efficiency to reduce the ventilation resistance. Thereby, in each of a 1st heat exchanger and a 2nd heat exchanger, a highly efficient heat exchanger can be provided, reducing ventilation resistance more.

  As described above, in the heat exchanger according to the present embodiment, the heat transfer tubes that penetrate the plate-like fins of the first heat exchanger and the second heat exchanger are located on the leeward side of the fin-width direction center of the plate-like fins. Therefore, it is possible to lengthen the time until the flow path is blocked by the plate-like fins 8 ″ due to frost formation. Also, there are a plurality of plate-like fins in the longitudinal direction of the first heat exchanger and the second heat exchanger. The height of the upwind chevron shape located at the windward end of the fin among the plurality of chevron shapes is formed lower than the height of other chevron shapes other than this upwind chevron shape In each of the first heat exchanger and the second heat exchanger, it is possible to provide a highly efficient heat exchanger while further reducing the ventilation resistance.

  In the present embodiment, the positions of the through holes of the plate-like fins 8 ″ of the leeward row (second heat exchanger B) and the leeward row (first heat exchanger A) are moved to the leeward side. Only the through holes of the plate-like fins 8 ″ in the windward row may be moved to the leeward side.

1 Compressor 2 Channel switching means (four-way valve)
3 Outdoor heat exchanger 4 Air conditioner throttle device (flow control valve)
DESCRIPTION OF SYMBOLS 5 Indoor heat exchanger 6 Outdoor ventilation means 7 Indoor ventilation means 8, 8 ', 8 "Plate-shaped fin 9 Heat-transfer tube 10A-10D, 11A-11D, 20A-20D, 21A-21D, 30A-30C, 31A-31C Yamagata Shapes 12A to 12D, 13A, 13B Refrigerant path 100 Air flow direction A First heat exchanger B Second heat exchanger

Claims (6)

A first heat exchanger and a second heat each having a plurality of plate-like fins arranged in the plate thickness direction, and heat transfer tubes provided in a plurality of stages in the longitudinal direction of the plate-like fins through the plate-like fins. The heat exchanger is configured as an integrated exchanger, in which a refrigerant flows inside the heat transfer tubes and heat is exchanged between air and the refrigerant by blowing air in a direction perpendicular to the plate thickness direction of the plate fins. And
The first heat exchanger is located on the windward side of the second heat exchanger;
The plate-like fins of the first heat exchanger and the second heat exchanger each have a chevron shape in the longitudinal direction, and are higher than the height of the chevron shape formed on the plate-like fin of the second heat exchanger. The chevron-shaped height formed on the plate-like fin of the first heat exchanger is formed low,
A heat exchanger in which a tube diameter of the heat transfer tube of the first heat exchanger is smaller than a tube diameter of the heat transfer tube of the second heat exchanger.   2. The heat exchanger according to claim 1, wherein the heat transfer tube penetrating the plate-like fin is located on the leeward side with respect to the fin width direction center of the plate-like fin. In Claim 1 or 2, the plate-like fins of the first heat exchanger and the second heat exchanger each have a plurality of chevron shapes in the longitudinal direction,
Among the plurality of chevron shapes, a heat exchanger in which the height of the windward chevron shape located at the windward end of the fin is lower than the heights of the chevron shapes other than the windward chevron shape . 4. The heat exchanger tube according to claim 1, wherein when the heat exchanger functions as an evaporator, the number of passes of the heat transfer tube increases toward the downstream side in the flow direction of the refrigerant, and the flow direction of the refrigerant and air The flow direction is parallel flow,
When the heat exchanger functions as a condenser, the number of passes of the heat transfer tubes decreases toward the downstream side in the flow direction of the refrigerant, and the heat exchange in which the flow direction of the refrigerant and the flow direction of the air are opposite to each other vessel.   The heat exchanger according to claim 4, wherein all the inlet portions of the refrigerant in the heat exchanger when the heat exchanger functions as a condenser are positioned in the second heat exchanger. A compressor, a flow path switching means, an outdoor heat exchanger, an expansion device for air conditioning operation, and a refrigeration cycle device in which an indoor heat exchanger is connected by a refrigerant pipe,
The said outdoor heat exchanger is an air conditioner which is a heat exchanger in any one of Claims 1 thru | or 5.

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