JP3177302U - Air conditioning unit - Google Patents

Abstract

An air-conditioning / air-conditioning apparatus in which piping is simplified, operation control is easy, and operation efficiency is improved.
An upwind heat exchanger (11) and a leeward wind turbine (11) having a compressor (5) and a heat exchanger (6) for an indoor unit and arranged side by side in series on the windward side and the leeward side of the outdoor air passage by serial connection. The side heat exchanger 12 is used as an outdoor unit heat exchanger. During heating, the high-temperature refrigerant flows to the windward heat exchanger 11, and then the refrigerant having a low temperature due to adiabatic expansion flows to the leeward heat exchanger 12. A cooling / heating air conditioner having a configuration in which a high-temperature refrigerant flows in the order of the leeward heat exchanger 12 and the windward heat exchanger 11 during cooling, in the windward heat exchanger 11 in both the cooling operation and the heating operation. A cooling and heating air conditioner having a configuration in which the refrigerant flows from the top to the bottom in the weight direction, and the distance between the windward side heat exchanger 11 and the leeward side heat exchanger 12 is 5 to 50 mm.
[Selection] Figure 1

Description

  The present invention relates to a heating / cooling air conditioner (system) characterized by a heat exchange device for an outdoor unit.

  In general, in an outdoor unit heat exchanger of an air conditioning / air conditioning system, when the temperature of the outside air decreases during heating operation, frost adheres to the outdoor unit heat exchanger, reducing the ventilation rate and the heat exchange rate. It was necessary to defrost to make it come. Therefore, the windward side heat exchanger and the leeward side heat exchanger arranged in parallel on the windward side and the leeward side with respect to the outdoor air passage are used as outdoor unit heat exchangers, and during heating, the high-temperature refrigerant is used as the windward side heat exchanger. A cooling and heating air conditioning system is known in which the refrigerant having a low temperature due to adiabatic expansion flows to the leeward heat exchanger and the high temperature refrigerant flows in the order of the leeward heat exchanger and then the windward heat exchanger during cooling. (See, for example, the claims of Patent Document 1 and FIGS. 1 and 2).

  As shown in FIG. 10, the air conditioning and air conditioning system described in Patent Document 1 includes a compressor 5, an indoor unit heat exchanger 6, an outdoor unit heat exchanger 10, and first and second electronic expansions. And valves EV1 and EV2. The outdoor unit heat exchanger 10 includes a windward heat exchanger 11 disposed on the windward side of the outdoor air passage 7 and a leeward heat exchanger 12 disposed on the leeward side. . A blower fan 13 for taking in outside air A is disposed on the windward side of the windward heat exchanger 11.

  Moreover, the 1st piping 21 which connects the compressor 5 and the indoor unit heat exchanger 6, and the 2nd piping which connects the compressor 5 and the leeward side heat exchanger 12 of the heat exchanger 10 for outdoor units. 22 is provided with a four-way valve DV which is a switching valve. By switching the four-way valve DV, the high-temperature and high-pressure refrigerant discharged from the compressor 5 flows to the indoor unit heat exchanger 6 or the leeward heat exchanger 12. The third pipe 23 that connects the indoor unit heat exchanger 6 and the windward heat exchanger 11 includes a first check valve CVa and a first electronic expansion valve EV1 that functions only during cooling. It is installed. The fourth pipe 24 connecting the windward side heat exchanger 11 and the leeward side heat exchanger 12 is provided with a second check valve CVb and a second electronic expansion valve EV2 that functions only during heating. Has been.

JP 2008-25897 A

  However, in the air conditioning air conditioning system described in Patent Document 1, since it is necessary to provide two electronic expansion valves in one air conditioning air conditioning system, the piping becomes complicated and the control of the electronic expansion valve becomes complicated, In addition, there are concerns such as increased costs.

  Further, in the air conditioning and air conditioning system described in Patent Document 1, with respect to the windward side heat exchanger in which the refrigerant (internal fluid) flowing inside is always in a liquid phase state having a large flow path resistance, the cooling and heating operations are performed. Since the refrigerant inflow direction is changed, there is a problem that the operation efficiency is lowered.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cooling / heating air conditioner that can simplify piping, facilitate operation control, and improve operation efficiency.

In order to solve the above problems, the present invention
A windward side heat exchanger and a leeward side heat exchanger that have a compressor and a heat exchanger for indoor units, and are arranged side by side in series on the windward side and the leeward side of the outdoor air passage by serial connection. Used as a heat exchanger for heating, high-temperature refrigerant flows to the leeward heat exchanger during heating, then low-temperature refrigerant due to adiabatic expansion flows to the leeward heat exchanger, and during cooling, the high-temperature refrigerant flows to the leeward side A heating and cooling air conditioner having a configuration in which the heat exchanger and the windward heat exchanger flow in this order,
A refrigerant inlet pipe connected to a refrigerant inlet provided at the upper end of the upwind heat exchanger;
A refrigerant outlet pipe connected to a refrigerant outlet provided at the lower end of the upwind heat exchanger;
An expansion mechanism interposed in the refrigerant outflow pipe;
A first branch pipe and a second branch pipe which are parallel to each other and connect the refrigerant inlet pipe and the refrigerant outlet pipe;
Each of the first and second branch pipes is connected in series to block the flow from the refrigerant inlet side to the refrigerant outlet side, and when the secondary side is at a high pressure relative to the primary side of the refrigerant flowing in the pipe. Two check valves to block the flow;
An outdoor pipe connecting the two check valves in the first branch pipe and a refrigerant outlet at the lower end of the leeward heat exchanger;
An indoor pipe connecting between the two check valves in the second branch pipe and the indoor heat exchanger;
At least the upwind heat exchanger includes a pair of header pipes provided with the refrigerant inlet and the refrigerant outlet, and a plurality of parallel flat heat exchange tubes communicating with the pair of header pipes, adjacent to each other. A parallel flow type heat exchanger composed of corrugated fins interposed between flat heat exchange tubes,
In both the cooling operation and the heating operation, the windward heat exchanger has a configuration in which the refrigerant flows from the top to the bottom in the weight direction,
The distance between the windward side heat exchanger and the leeward side heat exchanger is 5 to 50 mm,
It is related with the air-conditioning air conditioning apparatus characterized by these.

  Here, the expansion mechanism can be formed using, for example, an expansion valve or a capillary tube utilizing capillary action.

  In the air-conditioning / air-conditioning apparatus of the present invention having such a configuration, the control of one expansion mechanism and the check valve mechanism including a plurality of (four) check valves can be used during cooling operation and heating operation. In any case, the flow direction of the refrigerant into the upwind heat exchanger can be made constant.

  In addition, as a result of producing a number of prototypes and repeating intensive experiments, the inventors have determined that if the distance between the windward side heat exchanger and the leeward side heat exchanger is 5 mm or more, the windward side heat exchanger When the air flowing into the leeward side heat exchanger is agitated and sufficient frost formation effect can be ensured, and the distance between the leeward side heat exchanger and the leeward side heat exchanger is 50 mm or less, the dimensions of the air conditioner / air conditioner It has been found that sufficient heat exchange performance can be secured without increasing the size. In particular, when the distance between the windward side heat exchanger and the leeward side heat exchanger exceeds 50 mm, no further improvement in the heat exchange performance can be expected, and only the size of the air-conditioning / air-conditioning apparatus is increased.

  In the air-conditioning / air-conditioning apparatus according to the present invention, both the upwind heat exchanger and the downwind heat exchanger communicate with a pair of aluminum header pipes facing each other and the pair of header pipes. It is preferable that the parallel flow type heat exchanger is composed of aluminum flat heat exchange tubes parallel to each other and aluminum fins interposed between adjacent flat heat exchange tubes.

  According to the air-conditioning / air-conditioning apparatus of the present invention having such a configuration, both the windward side heat exchanger and the leeward side heat exchanger can have the same structure, and the thicknesses of both the heat exchangers can be set to fin and・ It can be made thinner than tube heat exchangers. In addition, by arranging the flat heat exchange tubes in the vertical direction, it is possible to make it difficult to collect the condensed water or water generated by defrosting attached to the flat heat exchange tubes. In addition, the heat exchanger can be thinned while maintaining high heat exchange performance.

  In the air conditioning / heating air conditioner of the present invention, the distance between the windward side heat exchanger and the leeward side heat exchanger is preferably 10 to 50 mm, and more preferably 30 to 50 mm.

  If the distance between the windward side heat exchanger and the leeward side heat exchanger is within the above range, the agitation of the air flowing from the windward side heat exchanger to the leeward side heat exchanger is more reliably suppressed while suppressing the size of the air conditioning air conditioner And sufficient frost effect and heat exchange performance can be secured.

In the cooling / heating air conditioner of the present invention, it is preferable that the ventilation resistance R ₁ of the windward heat exchanger is smaller than the ventilation resistance R ₂ of the leeward heat exchanger.

  According to the cooling / heating air conditioner according to the present invention having such a configuration, even if the entire area of the windward side heat exchanger and the entire area of the leeward side heat exchanger are substantially the same, the leeward side of the leeward side heat exchanger The pressure loss of the air flowing through the side heat exchanger can be reliably reduced, and the heat exchange performance can be improved.

  In the cooling / heating air conditioner of the present invention, it is preferable that the fin in the upwind heat exchanger is a louverless corrugated fin, and the fin in the leeward heat exchanger is a louvered corrugated fin. .

According to the air conditioning air conditioning apparatus of the present invention having such a configuration, even if the entire area of the windward heat exchanger and the entire area of the leeward heat exchanger are substantially the same, the windward heat exchanger and While the leeward side heat exchanger has substantially the same size, the ventilation resistance R ₁ of the leeward side heat exchanger can be surely made smaller than the ventilation resistance R ₂ of the leeward side heat exchanger. The pressure loss of the air flowing through the heat exchanger can be more reliably reduced, and the heat exchange performance can be improved.

  In the cooling / heating air conditioner of the present invention, it is preferable to provide a refrigerant inlet at the upper end of the upwind heat exchanger and provide the refrigerant outlet at the lower end of the upwind heat exchanger.

  With this configuration, the refrigerant flow to the windward heat exchanger can be flowed more reliably in the direction of gravity (from top to bottom), and the passage resistance value of the windward heat exchanger can be minimized. can do.

  According to this invention, since it is comprised as mentioned above, the following outstanding effects are acquired. In other words, according to the present invention, the control of one expansion mechanism and the check valve mechanism allow the high-temperature refrigerant after condensation to flow to the windward heat exchanger in both the cooling operation and the heating operation. The expansion mechanism is simplified, operation control is facilitated, and operation efficiency is improved.

  Further, the flow of the refrigerant to the windward heat exchanger can be made to flow in the direction of gravity (from top to bottom), and the passage resistance value of the windward heat exchanger can be suppressed to a minimum, so that the operation efficiency is further improved. It has improved.

It is a schematic block diagram which shows the state at the time of air_conditionaing | cooling operation | movement of the heat exchanger for outdoor units of the air conditioning air conditioning system which concerns on this invention. It is a schematic block diagram which shows the state at the time of the heating operation of the heat exchanger for outdoor units. It is sectional drawing which shows the state at the time of the cooling operation of the non-return valve in this invention. It is sectional drawing which shows the state at the time of heating operation of the non-return valve in this invention. It is a schematic block diagram which expand | deploys and shows the leeward side heat exchanger and leeward side heat exchanger in this invention. It is a perspective view which shows an example of the windward side heat exchanger 11 and the leeward side heat exchanger 12. FIG. The partial enlarged view (a) which shows the structure of the fin (louverless) 17 of the windward side heat exchanger 11 and the structure of the fin (with louver) 17 of the leeward side heat exchanger 12 in the heating / cooling air conditioner 1 of FIGS. (B) (The figure seen from the direction substantially parallel to the length direction of the flat heat exchange pipe | tube 16), respectively. It is a partial photograph which shows an example of the structure of the fin (with louver) 17 and the flat heat exchange pipe | tube 18 of the leeward side heat exchanger 12 in the air conditioning air conditioner 1 of FIG.1 and FIG.2. It is a perspective view which shows the example of the other heat exchanger which can be used for the heat exchanger 10 for outdoor units. It is a schematic block diagram which shows the heat exchanger for outdoor units of the conventional air-conditioning / air-conditioning system.

  Hereinafter, an embodiment of a heat exchange device for an outdoor unit of an air conditioning and air conditioning system according to the present invention will be described in detail with reference to the accompanying drawings. Here, the same parts as those of the conventional outdoor unit heat exchange device will be described with the same reference numerals.

  The air conditioning and air conditioning system according to the present invention includes an outdoor unit heat exchanger 10 including an upwind heat exchanger 11 and a leeward heat exchanger 12 that are arranged in parallel on the upwind side and downwind side with respect to the outdoor air passage, and the upwind side. A refrigerant inlet pipe 31 connected to the refrigerant inlet 18a provided at the upper end of the heat exchanger 11, a refrigerant outlet pipe 32 connected to the refrigerant outlet 18b provided at the lower end of the windward heat exchanger 11, and the refrigerant An expansion mechanism provided in the outflow pipe 32, for example, an expansion valve EV, a first branch pipe 33 and a second branch pipe 34 connected in parallel to each other, connecting the refrigerant inflow pipe 31 and the refrigerant outflow pipe 32, and A check valve mechanism 40, which will be described later, consisting of a total of four check valves CV1, CV2, CV3, and CV4 interposed in the second branch pipes 33 and 34, and two check valves in the first branch pipe 33 Refrigerant flow between CV1 and CV2 and at the lower end of the leeward heat exchanger 12 The outdoor side pipe 35 connecting the inlet 18d, the space between the two check valves CV3 and CV4 in the second branch pipe 34, and the indoor unit heat exchanger 6 (hereinafter referred to as the indoor side heat exchanger 6) And a first indoor side pipe 36 to be connected.

  The second indoor pipe 37 connecting the leeward heat exchanger 12 and the indoor heat exchanger 6 is provided with a four-way valve DV and a compressor 5 in order from the leeward heat exchanger 12 side. The high-temperature and high-pressure refrigerant discharged from the compressor 5 flows through the indoor unit heat exchanger 6 or the leeward heat exchanger 12 of the outdoor unit heat exchanger 10 by switching the four-way valve DV. It has become.

  As shown in FIGS. 1 to 4, the check valve mechanism 40 includes a first branch pipe 33 and a second branch pipe 34 that connect the refrigerant inflow pipe 31 and the refrigerant outflow pipe 32 in parallel with each other. In other words, the first check valve CV1 and the second check valve CV2 that are interposed in series with the first branch pipe 33 and the other branch pipe, that is, the second branch pipe 34, are connected in series. The third check valve CV3 and the fourth check valve CV4 are four check valves. In this case, the check valves CV1 to CV4 block the flow from the refrigerant inlet 18a side to the refrigerant outlet 18b side and to the primary side of the refrigerant flowing in the first and second branch pipes 33 and 34. On the other hand, the secondary side has a function of blocking the flow when the pressure is high.

  In the check valve mechanism 40 formed as described above, refrigerant flows out of the first branch pipe 33 between the first check valve CV1 and the second check valve CV2 and at the lower end of the leeward heat exchanger 12. The inlet 18d is connected to the outdoor pipe 35. Further, the third check valve CV3 and the fourth check valve CV4 in the second branch pipe 34 and the indoor heat exchanger 6 are connected by the first indoor pipe 36.

  Both the windward side heat exchanger 11 and the leeward side heat exchanger 12 constituting the outdoor unit heat exchanger 10 are formed of aluminum alloy parallel flow type heat exchangers. Immediately, as shown in FIGS. 5 and 6, the windward side heat exchanger 11 and the leeward side heat exchanger 12 include a pair of header pipes 14 and 15 made of aluminum alloy facing each other, and the header pipes 14 and 14. 15, a plurality of flat heat exchange pipes 16 made of, for example, extruded shapes made of parallel aluminum alloys, and corrugated fins 17 made of aluminum alloy interposed between adjacent flat heat exchange pipes 16. It is configured.

  In this case, the upper header pipe 14 of the windward side heat exchanger 11 is provided with a refrigerant inlet 18a to which the refrigerant inflow pipe 31 is connected, and the lower header pipe 15 of the windward side heat exchanger 11 is provided with a refrigerant outlet pipe. The refrigerant | coolant outflow port 18b to which 32 is connected is provided. On the other hand, the upper header pipe 14 of the leeward heat exchanger 12 is provided with a refrigerant inflow / outlet port 18c to which the first indoor pipe 36 is connected, and the lower header pipe 15 of the leeward heat exchanger 12 has a first header pipe 15c. A refrigerant inlet / outlet port 18d to which the two indoor pipes 37 are connected is provided. The flat heat exchange pipe 16 has a plurality of refrigerant passages (not shown) defined therein. Further, the upper and lower header pipes 14 and 15, the flat heat exchange pipe 16 and the corrugated fins 17 are integrally formed by brazing, for example.

  As described above, by forming the windward side heat exchanger 11 and the leeward side heat exchanger 12 with a parallel flow type heat exchanger, a plurality of meandering heat transfer tubes are penetrated through the heat transfer fins. Since the thickness can be reduced as compared with the And-tube type heat exchanger, the installation space of the outdoor unit heat exchanger 10 can be saved, that is, the outdoor unit heat exchanger 10, the expansion valve EV and the reverse. Space saving of the outdoor unit 50 that accommodates the valve stop mechanism 40 and the like can be achieved. In FIG. 5, reference numeral 60 is an indoor unit that houses the indoor heat exchanger 6. In addition, when comparing parallel flow heat exchangers and fin-and-tube heat exchangers with the same ventilation area, ventilation resistance, and heat exchange performance, parallel flow heat exchangers have fin-and-tube heat exchangers. For the exchanger, the heat exchanger thickness dimension can be halved.

  In addition, although the said embodiment demonstrated the case where an expansion mechanism was formed with the expansion valve EV, it may replace with the expansion valve EV and may form an expansion mechanism with the capillary tube using a capillary phenomenon.

  Here, the inventors of the present invention produced many prototypes and repeated diligent experiments. As a result, the distance W (see FIGS. 1 and 2) between the windward side heat exchanger 11 and the leeward side heat exchanger 12 is If it is 5 mm or more, agitation of the air flowing from the windward side heat exchanger 11 to the leeward side heat exchanger 12 can be promoted to ensure sufficient heat exchange performance, and the windward side heat exchanger 11 and the leeward side heat exchanger 12 It has been found that if the distance is 50 mm or less, sufficient heat exchange performance can be ensured without increasing the size of the air-conditioning and air-conditioning apparatus. In particular, when the distance between the windward side heat exchanger 11 and the leeward side heat exchanger 12 exceeds 50 mm, further improvement in the heat exchange performance cannot be expected, and only the size of the air-conditioning and air-conditioning apparatus is increased.

  If the distance W between the windward side heat exchanger 11 and the leeward side heat exchanger 12 is 5 mm or more, the distance between the windward side heat exchanger 11 and the leeward side heat exchanger 12 is within the above range. For example, the airflow between the windward side heat exchanger 11 and the leeward side heat exchanger 12 is not easily disturbed, and the space in the air conditioning / air conditioning apparatus 1 is not excessively taken. In particular, the present inventors have confirmed through experiments that the heat exchange performance is substantially constant and does not change when the distance W exceeds 50 mm. The distance W between the windward side heat exchanger 11 and the leeward side heat exchanger 12 is preferably 10 to 50 mm, and more preferably 30 to 50 mm.

  Next, in the air conditioning air conditioner of this embodiment, in the windward side heat exchanger 11, the corrugated fins 17a disposed between the flat heat exchange tubes 16 are flat as shown in FIG. In the leeward side heat exchanger 12, as shown in FIG. 7B and FIG. 8, the corrugated fins 17b disposed between the flat heat exchange tubes 16 are In addition, it may have a shape (with a louver) that is flat and has a large number of slit-shaped openings 17c provided in parallel (of course, either the windward side heat exchanger 11 or the leeward side heat exchanger 12). 7 may have the structure shown in FIG. 7 (a) or the structure shown in FIG. 7 (b) and FIG.

With such a structure, it is preferable that the ventilation resistance R ₁ of the windward side heat exchanger 11 is set smaller than the ventilation resistance R _{2 of the} leeward side heat exchanger 12. The ventilation resistance has substantially the same meaning as the pressure loss in general, and when the ventilation resistance R ₁ of the windward side heat exchanger 11 is equal to or larger than the ventilation resistance R _{2 of the} leeward side heat exchanger 12, the leeward side The air volume supplied to the heat exchanger 12 tends to decrease, and the heat exchange performance tends to be impaired. Therefore, in the present embodiment, as described above, the ventilation resistance R ₁ of the windward side heat exchanger 11 is set to be smaller than the ventilation resistance R _{2 of the} leeward side heat exchanger 12, and the outside air A flowing through the outside air ventilation path 7. The pressure loss received by the windward side heat exchanger 11 is reduced, and the deterioration of the heat exchange performance is effectively suppressed.

  Regarding the unit of ventilation resistance, “Pa (AF−0.5 m / sec)” means the ventilation resistance when the passing wind speed is 0.5 m / sec, and “Pa (AF-1. “5 m / sec)” means a ventilation resistance when the passing wind speed is 1.5 m / sec. The passing wind speed in the present embodiment is determined in the range of 0.5 to 3.0 m / sec, preferably in the range of 0.5 to 1.5 m / sec in consideration of the balance between heat exchange performance and quietness. do it.

More specifically, the pressure loss of the air flowing from the windward side heat exchanger 11 to the leeward side heat exchanger 12 can be reliably reduced, the heat exchange performance can be improved, and the function of the air conditioner / air conditioner 1 can be improved. From the viewpoint that it can be more reliably exhibited, for example, the ventilation resistance R ₁ of the windward side heat exchanger 11 is set to 2 Pa (AF-0.5 m / sec) to 14 Pa (AF-3.0 m / sec), it is preferable to set the ventilation resistance R ₂ of the leeward side heat exchanger 12 to 3Pa (AF-0.5m / sec) ~28Pa (AF-3.0m / sec). Furthermore, the ventilation resistance R ₁ of the leeward heat exchanger 11 is set to 2 Pa (AF−0.5 m / sec) to 14 Pa (AF−1.5 m / sec), and the ventilation resistance R of the leeward heat exchanger 12 is set. ₂ is preferably set to 3 Pa (AF-0.5 m / sec) to 28 Pa (AF-1.5 m / sec).

The airflow resistance is the pitch of the corrugated fins 17 (fp: distance between peaks and valleys), and the core thicknesses of the windward side heat exchanger 11 and the leeward side heat exchanger 12 (thickness of the portion serving as the core, in the present embodiment). It can also vary depending on the width of the flat heat exchange tube 16. For example, the core thickness is 14, 16, 19 or 21 mm, and fp is appropriately selected in the range of 1.0 to 2.5, but depending on these selected specific values, the windward side heat exchanger 11 the ventilation resistance R ₁ and the ventilation resistance R ₂ of the leeward side heat exchanger 12, may be set to the above range of airflow resistance.

  Moreover, in the said embodiment, although the windward side heat exchanger 11 and the leeward side heat exchanger 12 were made into the parallel flow type heat exchanger made from the aluminum alloy which has the header pipes 14 and 15 facing up and down, For example, as shown in FIG. 9, the windward side heat exchanger 11 may be a parallel flow type heat exchanger made of aluminum alloy having header pipes facing left and right. FIG. 9 is an example of a fin-and-tube heat exchanger 102 in which a plurality of rows of meandering heat transfer tubes 104 are passed through the heat transfer fins 103 (however, in FIG. 9, header pipes facing left and right are omitted). Has been).

Moreover, although the said embodiment demonstrated the case where the magnitude | size of the leeward side heat exchanger 11 and the leeward side heat exchanger 12 was made the same, the height and area of the leeward side heat exchanger 11 are made into leeward side heat exchange. The pressure loss can be further reduced to 1/4 to 2/3 of the vessel 12.
In addition, it is preferable that the windward side heat exchanger 11 and the leeward side heat exchanger 12 are attached to the frame of the outdoor unit and have a vibration isolation effect as in the conventional case.

  Next, operation | movement of the air-conditioning / air-conditioning system using the heat exchanger 10 for outdoor units which concerns on this invention is demonstrated with reference to FIGS.

<During cooling operation>
During the cooling operation, as indicated by arrows in FIGS. 1 and 3, the refrigerant that has passed through the expansion valve EV (expansion mechanism) and has been reduced in pressure by adiabatic expansion is supplied to the fourth check valve CV4 of the check valve mechanism 40. It passes through and flows into the indoor heat exchanger 6 and is evaporated. At this time, the second check valve CV2 and the third check valve CV3 do not function as flow paths because the valve back is filled with high-pressure refrigerant (see FIG. 3).

  The refrigerant that has passed through the indoor heat exchanger 6 passes through the four-way valve DV → the compressor 5 → the leeward heat exchanger 12, and the first check valve in the first branch pipe 33 via the outdoor pipe 35. It flows between CV1 and the second check valve CV2. The refrigerant that has returned to the check valve mechanism 40 passes through the first check valve CV1. At this time, the second check valve CV2 and the third check valve CV3 do not function as flow paths because of the valve check function (see FIG. 3).

  The refrigerant that has passed through the first check valve CV1, that is, the high-temperature condensate, flows in the direction of gravity (from top to bottom) from the refrigerant inlet 18a at the upper end of the windward heat exchanger 11. Thereby, while the windward side heat exchanger 11 functions as a subcooler and the passage resistance value of the windward side heat exchanger 11 can be suppressed to the minimum, the operating efficiency can be improved.

<During heating operation>
During the heating operation, as indicated by an arrow in FIG. 2, the refrigerant that has passed through the expansion valve EV (expansion mechanism) and has been reduced in pressure by adiabatic expansion passes through the second check valve CV <b> 2 of the check valve mechanism 40, It flows to the leeward heat exchanger 12 and is evaporated. At this time, the first check valve CV1 and the fourth check valve CV4 do not function as flow paths because the valve back is filled with high-pressure refrigerant (see FIG. 4).

  The refrigerant that has passed through the leeward heat exchanger 12 passes through the four-way valve DV → the compressor 5 → the indoor heat exchanger 6 and passes through the first indoor pipe 36 and the third branch pipe 34 through the third branch pipe 34. It flows between the check valve CV3 and the fourth check valve CV4. The refrigerant that has returned to the check valve mechanism 40 passes through the third check valve CV3. At this time, the first check valve CV1 and the fourth check valve CV4 do not function as flow paths because of the valve check function (see FIG. 4).

  The refrigerant that has passed through the third check valve CV3, that is, the high-temperature condensate, flows in the direction of gravity (from top to bottom) from the refrigerant inlet 18a at the upper end of the windward heat exchanger 11. Thereby, since the passage resistance value of the windward side heat exchanger 11 can be suppressed to the minimum, the operation efficiency is improved.

  As described above, according to the heat exchange device for an outdoor unit according to the present invention, the air flow is controlled in both the cooling operation and the heating operation by controlling one expansion valve EV (expansion mechanism) and the check valve mechanism 40. Since the inflow direction of the refrigerant to the upper heat exchanger 11 can be made constant, the piping is simplified, operation control is facilitated, and operation efficiency is improved.

5 ... Compressor,
6 ... Indoor heat exchanger,
10 ... heat exchanger for outdoor unit,
11 ... windward heat exchanger,
12 ... leeward heat exchanger,
18a ... refrigerant inlet,
18b ... refrigerant outlet,
31 ... Refrigerant inlet pipe,
32 ... refrigerant outlet pipe,
33 ... 1st branch pipe,
34 ... second branch pipe,
35 ... outdoor pipe,
36: first indoor side pipe,
37 ... second indoor side pipe,
40: Check valve mechanism,
EV: expansion valve (expansion mechanism),
CV1 to CV4... First to fourth check valves.

Claims (4)

A windward side heat exchanger and a leeward side heat exchanger that have a compressor and a heat exchanger for indoor units, and are arranged side by side in series on the windward side and the leeward side of the outdoor air passage by serial connection. Used as a heat exchanger for heating, high-temperature refrigerant flows to the leeward heat exchanger during heating, then low-temperature refrigerant due to adiabatic expansion flows to the leeward heat exchanger, and during cooling, the high-temperature refrigerant flows to the leeward side A heating and cooling air conditioner having a configuration in which the heat exchanger and the windward heat exchanger flow in this order,
A refrigerant inlet pipe connected to a refrigerant inlet provided at the upper end of the upwind heat exchanger;
A refrigerant outlet pipe connected to a refrigerant outlet provided at the lower end of the upwind heat exchanger;
An expansion mechanism interposed in the refrigerant outflow pipe;
A first branch pipe and a second branch pipe which are parallel to each other and connect the refrigerant inlet pipe and the refrigerant outlet pipe;
Each of the first and second branch pipes is connected in series to block the flow from the refrigerant inlet side to the refrigerant outlet side, and when the secondary side is at a high pressure relative to the primary side of the refrigerant flowing in the pipe. Two check valves to block the flow;
An outdoor pipe connecting the two check valves in the first branch pipe and a refrigerant outlet at the lower end of the leeward heat exchanger;
An indoor pipe connecting between the two check valves in the second branch pipe and the indoor heat exchanger;
At least the upwind heat exchanger includes a pair of header pipes provided with the refrigerant inlet and the refrigerant outlet, and a plurality of parallel flat heat exchange tubes communicating with the pair of header pipes, adjacent to each other. A parallel flow type heat exchanger composed of corrugated fins interposed between flat heat exchange tubes,
In both the cooling operation and the heating operation, the windward heat exchanger has a configuration in which the refrigerant flows from the top to the bottom in the weight direction,
The distance between the windward side heat exchanger and the leeward side heat exchanger is 5 to 50 mm,
Air-conditioning air conditioner characterized by. Each of the windward side heat exchanger and the leeward side heat exchanger includes a pair of header pipes provided with the refrigerant inlet and the refrigerant outlet, and a plurality of parallel pipes communicating with the pair of header pipes. A parallel flow type heat exchanger composed of flat heat exchange tubes and corrugated fins interposed between the adjacent flat heat exchange tubes,
The air-conditioning air conditioning apparatus of Claim 1 characterized by these. The ventilation resistance R ₁ of the leeward heat exchanger is smaller than the ventilation resistance R ₂ of the leeward heat exchanger;
The air conditioning air conditioning apparatus according to claim 1 or 2. The fins in the windward heat exchanger are louverless corrugated fins, and the fins in the leeward heat exchanger are corrugated fins with louvers,
The air conditioning air conditioning apparatus according to claim 2 or 3.