KR100664538B1 - Secondary heat exchanger for air conditioner - Google Patents

Abstract

The secondary heat exchanger for an air conditioner according to the present invention includes a connection connector having a coolant inlet flow path and a coolant discharge flow path respectively connected to a coolant inlet port and a coolant outlet port of a heat exchanger having a coolant inlet tank and a coolant discharge tank on one side thereof; A main body bonded to the connection connector and having a plurality of refrigerant inflow passages and refrigerant discharge passages connected to and connected to the refrigerant inflow passage and the refrigerant discharge passage, respectively; A block connector bonded to an upper end of the main body, and having a refrigerant inflow passage connecting the main body refrigerant inflow passage to the refrigerant discharge line of the condenser and a refrigerant discharge passage connecting the main body refrigerant discharge passage to the compressor refrigerant suction line; And an orifice tube for refrigerant throttling installed on the refrigerant inlet flow path of the connection connector. According to such a configuration, the liquid refrigerant of the high temperature and high pressure before being throttled is exchanged with the liquid refrigerant of the low temperature and low pressure downstream of the evaporator. In order to stabilize the refrigerant flow, the cooling performance of the air conditioner can be greatly improved. In addition, the configuration and the refrigerant piping structure are greatly simplified, so that the air conditioner can be miniaturized and highly efficient, and the increase in cost due to the addition of the secondary heat exchanger can be suppressed as much as possible.

Air Conditioner, Evaporator, Secondary Heat Exchanger, Supercooling

Description

Secondary heat exchanger for air conditioner {SECONDARY HEAT EXCHANGER FOR AIR CONDITIONER}

1 is a block diagram showing the configuration of a general air conditioner.

Figure 2 is a block diagram showing the configuration of an air conditioner having a secondary heat exchanger.

Figure 3 is a block diagram showing the configuration before and after the evaporator having a secondary heat exchanger for an air conditioner according to the present invention.

Figure 4 is a perspective view of the evaporator installed secondary heat exchanger for an air conditioner according to an embodiment of the present invention.

5 is an exploded perspective view of a secondary heat exchanger for an air conditioner according to an embodiment of the present invention.

6 is a cross-sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a sectional view taken along line VIII-VIII in FIG. 5; FIG.

<Description of Symbols for Main Parts of Drawings>

4: evaporator 7: secondary heat exchanger

71: connection connector 71a, 72a: refrigerant inlet flow path

71b, 72b: refrigerant discharge passage 71d: refrigerant discharge tank

72: main body 73: cap

74: Block Connector 712: Orifice Tube

713: flow control valve 716: diaphragm

721: fin fin 722: heat exchange tube

The present invention relates to a secondary heat exchanger of an air conditioner which improves cooling performance by stabilizing a refrigerant flow by exchanging heat with a liquid refrigerant of a low temperature low pressure on the downstream side of an evaporator before condensing the liquid refrigerant of a high temperature and high pressure in the air conditioner. In particular, the present invention relates to a secondary heat exchanger of an air conditioner, which is simple in construction and low in manufacturing cost and can contribute to miniaturization of the air conditioner.

The air conditioner of the vehicle is installed for cooling and heating the interior of the car during the summer or winter, or to remove the frost caused by the wind shield during the rain or winter, so that the driver can secure the front and rear view. As an interior of a vehicle, such an air conditioner is usually equipped with a heating system and a cooling system at the same time, and after the air or bet is selectively introduced, the air is heated or cooled to blow into the interior of the vehicle to cool the interior of the vehicle. Heat or vent.

The air conditioning system equipped with the air conditioner as described above cools the interior of a vehicle by dissipating heat inside the vehicle to the outside through the refrigerant while circulating the refrigerant that is a heat exchange medium by a conventional refrigeration cycle.                         

In general, as shown in FIG. 1, a cooling system of an air conditioner includes a compressor 1 for compressing a refrigerant, a condenser 2 for condensing the refrigerant compressed in the compressor 1, and a condenser ( 2) an expansion valve (3) which rapidly expands the condensed and liquefied refrigerant, and evaporates the refrigerant expanded by the expansion valve (3) to use air that is blown into the vehicle interior by using the latent heat of evaporation of the refrigerant. It includes a refrigeration cycle consisting of an evaporator (4) for cooling, thereby cooling the interior of the vehicle through the following circulation process.

First, while the compressor 1 is driven by the power of the engine, the low-temperature, low-pressure gaseous refrigerant is compressed and discharged to the condenser 2 in a gas state of high temperature and high pressure, and the condenser 2 is in a state of high temperature and high pressure by the compressor 1. Refrigerant is condensed by the blowing action of a cooling fan (not shown) to form a liquid of medium temperature and high pressure. The refrigerant, which has come out of the liquid state of medium temperature and high pressure in the condenser 2, is rapidly expanded by the throttling action of the expansion valve 3, and is sent to the evaporator 4 in a state of low temperature and low pressure wet saturated gas, and the evaporator 4 is expanded. The refrigerant is evaporated by heat exchange with external air and sent back to the compressor (1) as a low temperature low pressure gas. At this time, a blower fan (not shown) introduces indoor / outdoor air of the vehicle and blows it into the interior of the vehicle through the evaporator 4 so that the blowing air is cooled by the latent heat of evaporation of the liquid refrigerant in the evaporator 4 and then flows into the vehicle interior. The car's interior is cooled. For reference, reference numeral 5 in FIG. 1 represents a receiver drier (Receiver Drier) which serves to separate the gaseous refrigerant mixed in the liquid refrigerant from the condenser 2 and to send only the liquid refrigerant to the expansion valve 3. .

In the cooling operation of the air conditioner as described above, the refrigerant brought into a low-temperature low-pressure wet state by the throttling of the expansion valve 3 is heat-exchanged with the air blown into the vehicle interior while passing through the evaporator 4. . At this time, the subcooling of the refrigerant is a factor directly affecting the cooling efficiency of the air conditioner. When the subcooling of the refrigerant is increased, the refrigerant flow is stabilized and the amount of refrigerant pressure drop in the evaporator decreases. The cooling efficiency of the compressor is increased and the power consumption of the compressor is also reduced.

The secondary heat exchanger 6 of the air conditioner shown in FIG. 2 is for increasing the supercooling degree of the refrigerant flowing into the evaporator 4, and the high temperature and high pressure before being throttled by the throttling mechanism (expansion valve) 3. By cooling the liquid refrigerant with the low-temperature, low-pressure gaseous refrigerant on the downstream side of the evaporator, the refrigerant flow is stabilized, and the flow rate decreases due to the decrease of the specific volume of the refrigerant, contributing to the decrease in the pressure drop in the refrigerant pipe and the heat exchanger. Increasing the efficiency of the system reduces the compressor power consumption. In addition, by optimizing the superheat degree of the low-pressure refrigerant on the discharge side of the evaporator 4 to reduce the specific volume of the refrigerant flowing into the compressor 1, the volumetric efficiency of the compressor 1 is maximized, and consequently, the efficiency of the cooling system is increased.

As described above, the secondary heat exchanger exchanges heat between the high temperature and high pressure gaseous refrigerant before being throttled by the expansion valve and the gaseous refrigerant of the low temperature and low pressure downstream of the evaporator, thereby supercooling the refrigerant before being throttled and reducing the superheat degree of the refrigerant flowing into the compressor. By making it suitable, the compressor 1, the condenser 2, and the evaporator 4 will be highly efficient. Accordingly, it is possible to reduce the design of the condenser 2 and the evaporator 4 can contribute to the high efficiency and miniaturization of the air conditioner.

However, in spite of these advantages, the conventional secondary heat exchanger has a complicated configuration and increases the size of the air conditioner, and in addition, the pressure drop is excessively generated at various connections caused by the complicated entanglement of the pipes. There was a problem that there was a limit to increase.

A partial solution to this problem is the secondary heat exchanger disclosed in Japanese Patent Application Laid-Open No. 6-185831. The secondary heat exchanger was assembled integrally on the side of the evaporator, but the volume occupied by the secondary heat exchanger was reduced. Another problem is that the structure is complicated by the addition of a dual throttling function and a refrigerant bypass circuit.

In addition, the secondary heat exchanger disclosed as Japanese Patent Application Laid-open No. Hei 10-103812 reduces the number of components by incorporating a throttling mechanism into the heat exchanger, but has a disadvantage in that the piping structure between the components is complicated and there are many connections. there was.

In addition, the conventional secondary heat exchangers as described above use an expansion valve as a refrigerant throttling mechanism, which greatly increases the refrigerant flow rate when the cooling load is small, and often causes the air conditioner to be in an uncontrollable state. there was. That is, the opening amount of the expansion valve is controlled by a thermostat and a pressure equalizing tube sensing the two-phase refrigerant at the evaporator outlet near the saturation due to the presence of the liquid phase and the gaseous phase. Since the temperature and pressure change depending on the characteristics, the expansion valve is fully opened due to its low temperature, and the flow rate is greatly increased. At this time, the evaporator pressure in the evaporator is greatly increased, the cooling performance is drastically reduced, the power consumption of the compressor is also greatly increased, and the air conditioner is in an uncontrolled state.

To solve this problem, the first method is to install a pressure drop at the outlet of the secondary heat bridge, the second is to introduce a new external heat source to overheat the refrigerant, and the third is to bypass the secondary heat exchanger. Although a method of bypassing the refrigerant when the cooling load is small may be devised, the first method has a problem of lowering the cooling performance by increasing the evaporation pressure, and the second and third methods are electric heaters or bypass lines. And other problems, which complicates the configuration.

In addition, the above-mentioned methods have a small cooling load because the opening degree of the expansion valve is adjusted by the temperature and pressure of the two-phase refrigerant which does not accurately reflect the phenomenon of the air conditioner due to the temperature and pressure change dependently. When the air conditioner is out of control state is not fundamentally solved.

Accordingly, the present invention solves the problems of the conventional automotive air conditioner as described above, and the accumulator is not required while the orifice tube is incorporated as the throttling mechanism. In addition to miniaturization and high efficiency, it is possible to minimize the increase in cost due to the addition of a secondary heat exchanger, as well as the current refrigerant flow of the air conditioner by a two-phase refrigerant with a temperature and pressure dependent change. It is an object of the present invention to provide a secondary heat exchanger for an air conditioner that does not render the air conditioner out of control even when the cooling load is low by controlling the refrigerant flow rate accurately reflecting the situation.

The secondary heat exchanger for an air conditioner according to the present invention devised for the purpose as described above, the refrigerant inlet and the refrigerant outlet of the heat exchanger having a refrigerant inlet tank and a refrigerant discharge tank on one side ('inlet' used in the description below) And 'discharge' are all based on the refrigerant flow direction of the evaporator); a connection connector having a refrigerant inflow passage and a refrigerant discharge passage respectively connected thereto; A main body bonded to the connection connector, the main body including a plurality of refrigerant inflow passages and refrigerant discharge passages connected to and connected to the connection connector refrigerant inflow passages and the connection connector refrigerant discharge passages, respectively; A block connector bonded to an upper end of the main body, the block inlet connecting a main body refrigerant inlet passage to a refrigerant discharge line of the condenser, and a refrigerant outlet passage connecting the main body refrigerant discharge passage to the compressor refrigerant suction line; And an orifice tube for refrigerant throttling installed on the refrigerant inlet flow path of the connection connector.

On the other hand, in the secondary heat exchanger for an air conditioner according to the present invention as described above, the main body is a hollow body, a plurality of heat exchange tubes, the main body refrigerant inlet flow path is built in the hollow portion, the outside of the tubes The hollow space remaining portion is characterized in that forming the main refrigerant discharge passage.

In addition, as a preferred feature, the diaphragm is built into the connection connector, the two diaphragms which are respectively connected to the connection connector refrigerant inlet flow path and the connection connector refrigerant discharge flow path are displaced in proportion to the pressure difference between the two compartments. and; It further comprises a flow control valve connected to the diaphragm to adjust the opening amount of the orifice tube in proportion to the displacement of the diaphragm in the orifice tube.

In addition, the heat exchanger header tank according to the present invention is bonded to the connection connector refrigerant inlet flow path and inserted into the inflow tank of the heat exchanger, and each of the plurality of refrigerant distribution holes formed in the upper and lower portions thereof, respectively. It further includes a distribution pipe for discharging and discharging the refrigerant through a preferred feature.

In addition, an upper end portion of the plurality of heat exchange tubes is inserted into an upper header portion that is joined to an upper end of the main body and is joined to a lower open surface thereof to form a refrigerant inlet tank part sealed from the main refrigerant discharge flow path, and the upper end of the plurality of heat exchange tubes is inserted into the outer circumference. Preferably it further comprises a cap having an inlet to which the refrigerant discharge pipe is connected.

The connection connector is partitioned by a lower header into which the lower ends of the plurality of tubes are inserted to form a refrigerant inflow tank portion between the tubes and the connection connector refrigerant inflow passage, and the main body refrigerant discharge passage and the connection. The connector refrigerant discharge passage has a space portion that forms a refrigerant discharge tank portion.

According to the secondary heat exchanger for an air conditioner according to the present invention comprising all of the above-described configuration, the liquid refrigerant in the high temperature and high pressure state is discharged from the evaporator while flowing along the heat exchange tube and flows out of the heat exchange tube and flows to the compressor side. By heat-exchanging with the refrigerant, the high-temperature, high-pressure liquid refrigerant before being throttled is supercooled by exchanging heat with the low-temperature, low-pressure liquid refrigerant on the downstream side of the evaporator. Maximize the volumetric efficiency to increase the efficiency of the cooling system.

Hereinafter, the functions and operations of the above components will be described in more detail with reference to the accompanying drawings.

3 of the accompanying drawings is a block diagram showing the evaporator 4 side configuration of the air conditioner including the secondary heat exchanger 7 for the air conditioner according to an embodiment of the present invention. (In the following description, both 'inflow' and 'outlet' of the refrigerant flow are based on the refrigerant flow direction to the evaporator.)

As shown, the secondary heat exchanger for the air conditioner is a refrigerant line flowing from the condenser 2 to the expansion valve (or orifice tube) 3 through the refrigerant lines 11 and 12 and the refrigerant line in the evaporator 4. The refrigerant flowing in the compressor 1 through the 14 and 15 is heat exchanged with each other.

In particular, the secondary heat exchanger according to the present invention, as shown in Figures 3, 4 and 6, the refrigerant flow inlet header tank 41, 42 is configured at the bottom of the evaporator 4, the refrigerant inlet (41a) And an outlet 42a is mounted on one side of the evaporator 4 configured to be adjacent to each other on one side of the header tanks 41 and 42, which is shown in FIGS. 4 and 5, the outer shape evaporator 4. A connection connector 71 joined to and fixed to the refrigerant inlet 41a and the outlet 42a of the cooling medium, a main body 72 coupled to the upper end of the connection connector 71, and a cap joined to an upper end of the main body 72. 73 and a block connector 74 joined to the main body 72 and the cap 73 to which the refrigerant discharge line 11 and the compressor refrigerant suction line 15 of the condenser 2 are connected. Are distinguished.                     

As shown in FIG. 6, a refrigerant inlet passage 71a and a refrigerant discharge passage 71b are formed in the connection connector 71 and adjacent to one side of the evaporator 4, respectively. Refrigerant inlet tanks connected to the refrigerant discharge ports 41b, respectively, and these flow paths 71a and 71b are isolated by the lower header 711 bent in the form of tracers in the space portions 71c and 71d formed at the center of the connection connector. It is connected to the part 71c and the refrigerant | coolant discharge tank part 71d, respectively. In addition, an orifice tube 712 is provided in the refrigerant inflow passage 71a to throttle the refrigerant flowing into the evaporator 4.

As shown in FIG. 6, the orifice tube 712 has a flow control valve 713 for adjusting the opening amount of the orifice tube 712, which is a refrigerant inflow passage 71a and a refrigerant discharge passage ( A diamond which is displaced by elastic force in the pressure difference between the two pressure chambers P1 and P2 and the upper and lower compression springs 714 and 715 respectively formed by communicating two pressure chambers P1 and P2 respectively connected to 71b). The opening of the orifice tube 712 is adjusted in proportion to the displacement of the diaphragm 716. That is, when the refrigerant pressure of the refrigerant inlet flow path 71a of the inlet side of the evaporator 4 increases relative to the pressure of the refrigerant in the refrigerant discharge flow path 71b flowing to the compressor 1 side (P1> P2), the flow rate control valve ( 713 moves downward (in the direction on the drawing) to increase the refrigerant inflow amount, and on the contrary, when the refrigerant flow rate is large and the refrigerant discharge pressure becomes larger than the refrigerant inflow pressure (P1 <P2), the orifice tube 712 is moved upward. Reducing the opening amount of) decreases the refrigerant flow rate. Thus, the flow rate of the orifice tube 712 is automatically adjusted by the action of the diaphragm 716 and the compression spring 714, 715 in accordance with the pressure correlation between the refrigerant inlet passage (71a) and the refrigerant discharge passage (71b). It is configured to be.

The orifice tube 712 is connected to the refrigerant inlet flow path 71a at the distal end of the orifice tube 712 through a plurality of refrigerant distribution holes 75a formed in the upper and lower coolant inlet header tanks 41 of the evaporator. Distribution pipe 75 for separating and discharging the refrigerant is connected. The distribution tube 75 serves to evenly distribute the refrigerant to each cooling tube 43 of the evaporator 4, in particular, the cooling tube 43 of the evaporator 4 in which the distribution tube 75 is installed. They have a U-shaped refrigerant flow path to reduce the pressure drop in the refrigerant flow. Therefore, the refrigerant flowing into the evaporator 4 flows evenly in each cooling tube 43 of the evaporator due to the distribution action of the distribution tube 75 and the U-shaped flow path structure of the cooling tubes 43. As a result, the temperature variation between the cooling tubes 43 of the evaporator 4 is reduced and the pressure drop amount is reduced, thereby increasing the heat exchange rate of the evaporator 4.

In general, when the flow distribution of the refrigerant is inadequate, a temperature deviation occurs in the core of the evaporator 4 formed by the cooling tubes 43, and when the pressure drop is large, two-phase flow (flow in which the gaseous refrigerant and the liquid refrigerant coexist) As much as the temperature difference corresponding to the pressure difference occurs. For example, in the case of HFC134a refrigerant, if the pressure drop in the core is 0.5 kgf / cm ^{2, the} temperature difference is about 5 ° C. Accordingly, the distribution pipe 75 evenly distributes the refrigerant flowing into the evaporator 4 to each cooling tube 43 of the evaporator core, thereby reducing the temperature deviation of the evaporator core and the pressure drop in the evaporator core to reduce the temperature of the air conditioner. It contributes to improving the cooling efficiency.

The main body 72 is a hollow miniature heat exchanger that heat-exchanges the liquid refrigerant of the high temperature and high pressure and the liquid refrigerant of the low temperature and low pressure downstream of the evaporator 4 before being throttled, as shown in FIGS. 5 and 7. A plurality of heat exchange tubes 722 are disposed through the heat dissipation fins 721. The heat exchange tubes 722 are connected to the refrigerant inlet tank portion 71c inside the lower header 711 of the connection connector 71 to become a refrigerant inflow passage 72a of the high pressure refrigerant introduced into the evaporator 4, The remaining space 72b inside the outer body 72 of the tube 722 communicates with the coolant outlet tank portion 71d of the lower header 711 to discharge the low pressure refrigerant discharged from the evaporator 4 to the outlet 72c of the upper part of the main body. It becomes a refrigerant discharge flow path (72b) leading to the compressor (1) side through.

A cap 73 is attached to an upper end of the main body 72, and a lower part of the cap 73 is sealed by an upper header 731 to which heat exchange tubes 722 of the main body are connected, and a refrigerant inlet tank part therein ( 73a) is formed.

As shown in FIG. 5, the block connector 74 is attached to the upper outer circumference of the main body 72 and the outer circumference of the cap 73 at the same time, and has two refrigerant inflow paths 74a therein. ) And a refrigerant discharge passage 74b, and the upper refrigerant inflow passage 74a is a refrigerant discharge line 73a in the cap 73 and a refrigerant discharge line of the condenser 2 (reference numeral 11 in FIG. 3). ) And the lower refrigerant discharge passage 74b connects the refrigerant discharge passage 72b of the main body 72 to the refrigerant suction line (reference numeral 15 in FIG. 3) of the compressor 1.

By the action of the respective components as described above, the secondary heat exchanger according to the present invention after the refrigerant discharged from the condenser 2 together with the evaporator (4) through the refrigerant inlet flow path (74a) of the block connector 74 , The refrigerant inlet tank portion 73a of the cap 73 → the refrigerant inflow passage 72a in the body heat exchange tube 722 → the refrigerant inlet tank portion 71c of the connecting connector 71 → the orifice tube 712 → distribution pipe (75) → Each cooling tube 43 of the evaporator 4 → Refrigerant discharge passage 71b of the connection connector 71 → Refrigerant discharge tank portion 71d of the connection connector 71 → Refrigerant discharge of the main body 72 The high pressure and high pressure refrigerant in the heat exchange tube 722 of the main body 72 and the outside thereof, while flowing to the refrigerant line 15b on the compressor 1 side in the order of the flow path 72b to the refrigerant discharge passage 74b of the block connector 74. The low temperature low pressure refrigerant of the heat exchange. 2 and 3, the high pressure side refrigerant (refrigerant in the heat exchange tube) is supercooled by heat exchange with the low pressure side refrigerant, throttled in the orifice tube 712, and flows into the evaporator 4, and low pressure. The refrigerant on the side (the refrigerant inside the body heat exchange tube) is exchanged with the high-pressure refrigerant to flow to the compressor 1 in a state where the dryness is increased to increase the superheat.

Therefore, the flow of the refrigerant is stabilized until the flow into the evaporator 4 and the flow rate is reduced due to the specific volume reduction, so that the amount of pressure drop in the refrigerant line 12 to 15 or the evaporator 4 is reduced. In the evaporator 4, the superheated region having a high temperature is reduced and the superheated section is formed in the secondary heat exchanger 7, so that the temperature deviation of the evaporator 4 is reduced, thereby increasing the heat exchange rate of the evaporator 4. As a result, the cooling efficiency of the cooling system increases, and the power consumption of the compressor 1 is greatly reduced.

In this process, as shown in FIG. 6, the flow control valve 713 embedded in the connection connector 71 is disposed between the refrigerant inflow passage 71a and the refrigerant discharge passage 71b inside the connection connector 71. According to the pressure correlation (pressure of P1 and P2) by the action of the diaphragm 716 and the compression spring 714, 715 to control the flow of the high-pressure side refrigerant flowing into the evaporator 4 to circulate the entire cooling cycle Automatically adjust the amount of refrigerant. The flow control valve 713 controls the refrigerant flow rate by accurately reflecting the current state of the air conditioner even with a two-phase refrigerant whose temperature and pressure change in a dependent manner, so that the air conditioner is in an uncontrollable state when the cooling load is small. Do not fall into.

Meanwhile, in the secondary heat exchanger of the present invention, the connection connector 71 illustrated in FIGS. 5 and 6 includes a function of connecting the evaporator 4 and the secondary heat exchanger 7 and an orifice tube 712 built therein. It has a function of throttling the refrigerant, in particular the refrigerant inlet tank portion 71c and the refrigerant discharge tank portion 71d partitioned by the lower header 711 therein, the evaporator (4) inlet line and outlet line Are simultaneously connected, which can greatly contribute to miniaturization of the secondary heat exchanger. In addition, the orifice tube 712 is built as a throttling mechanism for throttling the refrigerant supercooled by the secondary heat exchange therein, the orifice tube 712 can adjust the refrigerant flow rate to an appropriate level according to the cooling system control state. As the refrigerant flow rate control function is inferior to that of the expansion valve, an accumulator for filtering the liquid refrigerant from the compressor inlet refrigerant is usually used in order to prevent the liquid refrigerant from entering the compressor (1) depending on the operating condition of the cooling system. In the present invention, since the lower refrigerant discharge tank portion 71d of the connection connector 71 replaces the accumulator for storing the liquid refrigerant, the accumulator is unnecessary even though the orifice tube 712 is used. The advantage is that the configuration can be simplified.

In addition, the main body 72 of FIG. 5 in which heat exchange takes place is formed so that the cap 73 and the upper header 731 which are joined to the upper part to form the high-pressure side refrigerant inlet tank portion 73a are close to the spherical shape and the main body The heat dissipation fins 721 interposed between the heat exchange tubes 722 in the 72 disperse the pressure received by the heat exchange tubes 722 to have sufficient pressure resistance to withstand the high pressure of the refrigerant. In addition, since the heat exchange capacity can be adjusted by adjusting the length of the main body 72 and the density of the heat dissipation fins 721, various cooling systems can be adapted to the specifications required.

According to the secondary heat exchanger for an air conditioner according to the present invention as described in detail above, in the air conditioner, the refrigerant flows by superheating the liquid refrigerant of the low temperature and low pressure on the downstream side of the evaporator before condensing the liquid refrigerant of the high temperature and high pressure. By stabilizing the cooling performance of the air conditioner can be significantly improved. In addition, it is possible to prevent the liquid refrigerant from flowing into the compressor that causes damage to the compressor.

In addition, by accumulating orifice tubes as the throttling mechanism, no accumulator is required, which greatly simplifies the configuration and refrigerant piping structure, thereby miniaturizing and increasing the efficiency of the air conditioner, and minimizing the cost increase due to the addition of the secondary heat exchanger. Can be.

Particularly, the secondary heat exchanger for the air conditioner of the present invention controls the refrigerant flow rate by accurately reflecting the current state of the refrigerant flow of the air conditioner even by the two-phase state refrigerant in which the temperature and the pressure depend on the conventional air conditioner. Unlike secondary heat exchangers, it has the advantage that it does not make the air conditioner out of control even when the cooling load is small.

In addition, since the secondary heat exchanger for the air conditioner according to the present invention can easily change the heat exchange capacity according to the length of the main body and the density of the heat radiation fin, there is an advantage that it can be easily applied to the air conditioner of various specifications.

On the other hand, while the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the above-described embodiment, the field to which the invention belongs without departing from the spirit of the invention claimed in the claims below. Of course, anyone skilled in the art can make various modifications, as well as such modifications are within the scope of the claims.

Claims (7)

A connection connector having a refrigerant inlet passage and a refrigerant outlet passage connected to the refrigerant inlet and the refrigerant outlet of the heat exchanger having a refrigerant inlet tank and a refrigerant outlet tank at one side thereof, respectively; A main body bonded to the connection connector, the main body including a plurality of refrigerant inflow passages and refrigerant discharge passages connected to and connected to the connection connector refrigerant inflow passages and the connection connector refrigerant discharge passages, respectively; A block connector bonded to an upper end of the main body, and having a refrigerant inflow passage connecting the main body refrigerant inflow passage to the refrigerant discharge line of the condenser and a refrigerant discharge passage connecting the main body refrigerant discharge passage to the compressor refrigerant suction line; And And a refrigerant orifice tube for refrigerant throttling installed on the refrigerant inlet flow path of the connection connector. The method of claim 1, The main body is a hollow body, and the hollow portion has a plurality of heat exchange tubes which are the main body refrigerant inlet flow path, and the remaining space outside the heat exchange tubes forming the body refrigerant discharge passage Secondary heat exchanger for conditioner. The method of claim 1, A diaphragm embedded in the connection connector, the diaphragm being displaced in proportion to the pressure difference between the two pressure chambers by forming two pressure chambers respectively connected to the connection connector refrigerant inflow passage and the connection connector refrigerant discharge passage; And a flow rate control valve connected to a rod by a rod to adjust an opening amount of the orifice tube in proportion to the displacement of the diaphragm in the orifice tube. The method of claim 2 or 3, And a distribution pipe joined to the connection connector refrigerant inflow passage and inserted into the inflow tank of the heat exchanger to distribute and discharge the refrigerant through a plurality of refrigerant distribution holes respectively formed at upper and lower portions thereof. Secondary heat exchanger for air conditioning system. The method of claim 2 or 3, Upper ends of the plurality of heat exchange tubes are inserted into an upper header part joined to an upper end of the main body and joined to a lower open surface thereof to form a refrigerant inlet tank part sealed from the main refrigerant discharge flow path, and an upper end of the plurality of heat exchange tubes is inserted into an outer circumference of the condenser. A secondary heat exchanger for an air conditioner, further comprising a cap having an inlet to which a refrigerant discharge pipe is connected. The method of claim 2 or 3, The connection connector may be partitioned therein by a lower header into which lower ends of the plurality of heat exchange tubes are inserted to form a refrigerant inflow tank between the heat exchange tubes and the connection connector refrigerant inflow passage, and the main body refrigerant discharge passage. And a space portion forming a refrigerant discharge tank between the connection connector refrigerant discharge passages. The method of claim 4, wherein Secondary heat exchanger for an air conditioner, characterized in that the diameter of the distribution holes of the distribution pipe is larger from the orifice tube.

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