JP2588847Y2 - Automotive air conditioner condenser unit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-pass type multi-flow type condenser incorporated in an air conditioner for automobiles, and more particularly to a condenser unit capable of easily controlling the amount of refrigerant and maintaining constant supercooling.

[0002]

In general, cooling operation in the automotive air conditioner, the vaporized high-temperature high-pressure refrigerant discharged from the compressor as is well known condensed by a condenser, supplying the liquid refrigerant to the evaporator via the Rise Zhang valve Heat is exchanged with air in the evaporator, and the air cooled by the refrigerant is blown into the vehicle interior.

[0003] If there is a variation in heat load evaporator is subjected, the amount of refrigerant supplied to the evaporator is adjusted by controlling the opening of Rise Zhang valve, the excess refrigerant is generated provided downstream region of the condenser The liquid refrigerant is temporarily stored in the liquid tank, and when the refrigerant is insufficient, the refrigerant stored in the liquid tank is discharged to the evaporator.

[0004] However, the refrigerant in the cooling cycle leaks out of the cooling cycle during long-term use, and in some cases, excess refrigerant is sealed in the cooling cycle, and the refrigerant in the cooling cycle always has a predetermined amount. Not always. However, even in such a case, the refrigerant storage function of the liquid tank or the refrigerant storage function of the condenser itself enables a somewhat normal cooling operation, that is, a cooling operation with a predetermined subcool (degree of supercooling). I have.

[0005]

[Problem to be Solved by the Invention] A condenser unit of an air conditioner for an automobile comprises a condenser and the condenser.
Consists of a liquid tank provided in the vicinity of support, the capacitor, FIG higher performance with miniaturization of the whole shape
A so-called multi-path expression in order, the refrigerant is allowed to flow while U-turn within the capacitor.

As shown in FIGS. 3 and 4, a recent capacitor 10 is a straight flat tube open at both ends between a pair of header pipes 11 and 12 spaced apart by a predetermined length and arranged in parallel. 13 is the header pipe 1 in parallel with many rows.
The heat transfer fins f are interposed between the flat tubes 13 to form a core portion 14. Both ends of the header pipes 11 and 12 are hermetically closed by lids 15.
The inlet pipe 16 into which the refrigerant flows is connected to the other header pipe 12.
Are provided with outlet pipes 17 through which the refrigerant flows out. A partition plate 18 is provided in each of the header pipes 11 and 12, and the refrigerant flowing from the inlet pipe 16 passes through the header pipe 11 and enters a plurality of rows of flat tubes 13.
It flows in a meandering manner in the core 14 and flows out of the outlet pipe 17. That is, a so-called multi-pass type multi-flow type in which a number of paths (hereinafter, referred to as paths) in which the refrigerant flow flowing through the group of flat tubes 13 flows from one header pipe 11 to the other header pipe 12 is formed. It has become.

The header pipe 12 includes a bracket 1
9 is attached, and a liquid tank 20 is supported by the bracket 19. As shown in FIG. 4, the liquid tank 20 is provided with a main body 21 communicating with the outlet pipe 17, a desiccant 22 provided in the main body 21, and penetrated through the desiccant 22, and is suspended near the bottom of the main body 21. and a refrigerant take-out tube 23, the refrigerant take-out tube 23 is communicated with the bulging Zhang valve 24.

As described above, the recent condenser 10 is of a multi-pass type in which a large amount of refrigerant is caused to flow at once by a plurality of flat tubes 13 and is caused to flow in a meandering manner in a core 14.
Even if it is small, it is a high-performance capacitor with high heat exchange performance. Recently, there has been a demand for reducing the amount of refrigerant used from the viewpoint of protecting the global environment.

For this reason, the amount of refrigerant to be used is reduced for an air conditioner for an automobile. However, when a small amount of refrigerant is flown by using the above-described high-performance condenser, a slight change in heat load is caused. On the other hand, the state of the refrigerant in the condenser fluctuates, so that the cooling operation with a predetermined subcool (supercooling) is not performed stably, and there is a possibility that the temperature in the vehicle compartment may also fluctuate. For example, if the refrigerant charge is near or slightly less than appropriate, the refrigerant will only liquefy at the outlet of the condenser,
I can't get enough subcool. Therefore, the refrigerant in the condenser is in a saturated state of gas-liquid mixture, and is in an unstable state in which the refrigerant is gasified due to slight heat reception or pressure loss received by the outlet pipe or the like.

[0010] Therefore, in practice, the refrigerant flowing into the Rise Zhang valve repeats a liquid state and a gas state alternately, a so-called hunting state, the cooling performance of the evaporator is also lowered, air discharged into the passenger compartment (Hereinafter, the T value) also fluctuates.

In the case where the amount of the charged refrigerant is slightly excessive, the liquid refrigerant is used up to the final distribution path (hereinafter referred to as the final pass) after the refrigerant has meandered and circulated in the condenser. The liquid refrigerant is full. In this state, the liquid refrigerant in the final pass of the condenser is supercooled by air, so that the refrigerant is subcooled and expanded even if there is slight heat reception or slight pressure loss received at the outlet pipe or the like.
Refrigerant flowing into Zhang valve without the hunting state occurs, the refrigerant discharge pressure of the compressor, i.e. the pressure (hereinafter Pd values) of the refrigerant inlet portion of the capacitor although slightly increased, the cooling performance of the evaporator is improved The cycle is stable and the cooling power is secured.

[0012] However, this state is a one-point condition, and if the amount of refrigerant decreases even slightly, the state becomes unstable and is not practical. In other words, if the liquid tank is full of liquid refrigerant, the liquid tank can no longer accept the surplus refrigerant, and the liquid tank does not have the ability to manage the refrigerant amount, and the management width of the refrigerant amount is narrow. , Unstable,
It becomes difficult to control.

If the performance of the condenser having a different performance depending on the amount of the charged refrigerant is reduced in size and higher in performance, this tendency becomes more remarkable, and the amount of the charged refrigerant is adjusted so as to obtain the above-mentioned mild refrigerant overfilled state. However, it is difficult to maintain this state, and it is more difficult to secure cycle stability against changes in the amount of charged refrigerant, and it is difficult to control the amount of refrigerant in designing a capacitor. It is rare.

In some cases, the refrigerant is filled to a certain degree and the excess liquid refrigerant generated during operation is stored in a portion other than the heat exchange region of the condenser so that the condenser function of the condenser is not diminished. For example, a refrigerant storage tank provided below the condenser in communication with the inlet and the outlet (see Japanese Utility Model Laid-Open Publication No. 2-38,055), and a part of the header pipe on the outlet side of the condenser has a large diameter. (See Japanese Unexamined Patent Application Publication No. 2-48,765). However, these are only absorbs fluctuation of the refrigerant amount, and not to control the amount of refrigerant in consideration even subcooling that can be set in the condenser, a balanced liquid refrigerant subcooling (supercooling) to Rise Zhang valve Stable supply is not possible, and it is difficult to secure the stability of the cycle and the cooling power, and there is a possibility that the temperature of the air discharged from the passenger compartment may fluctuate. Further, even in this case, the amount of the charged refrigerant cannot be reduced, and when the amount of the used refrigerant is reduced, the width of managing the amount of the refrigerant cannot be increased.

The present invention has been made in view of such a problem, and enables a condenser to always set a desired subcool regardless of fluctuations in the amount of charged refrigerant, thereby increasing the control range of the amount of refrigerant. It is an object of the present invention to provide a high-performance and compact condenser unit for an air conditioner for a vehicle, which can secure cycle stability and cooling power.

[0016]

In order to achieve the above object, the present invention provides a core having a plurality of flat tubes having heat transfer fins interposed therebetween and having header portions at both ends thereof. A multi-pass type multi-flow type in which a heat exchange fluid flowing from an inlet pipe flows down while meandering in the core section until it reaches an outlet pipe by forming a partition plate in each of the header sections. In an air conditioner for a vehicle having a condenser, a final header portion in which refrigerant flowing out of a plurality of rows of flat tubes serving as the final pass is stored, and a plurality of headers having a predetermined internal volume and serving as the final pass.
The bottom is located at the same position as the top of the flat tubes in the row
Connected to the tank installed so that the connection pipe,
A capacitor unit of an automotive air conditioning system, characterized in that the lower portion of the discharge pipe and before Symbol final header portion for releasing refrigerant in the tank was connected by a connecting pipe. The number of rows of the flat tubes in the final pass is 1/4 to the number of rows of all flat tubes.
Preferably, the discharge pipe is connected to the inlet pipe of the liquid tank.

[0017]

In the condenser unit for an air conditioner for a vehicle according to the present invention, a part of the refrigerant liquefied in the final pass of the condenser is disposed at a predetermined position in the header pipe.
Flows into the tank via the connecting pipe attached to the
Make sure that the liquid refrigerant does not increase more than the connecting pipe in the pipe.
First, the refrigerant flows out of the condenser, and the remaining refrigerant flows out of the connection pipe connected to the header portion, and reaches the liquid tank or the like. Therefore, even if the liquid level on the condenser side fluctuates, the level of the liquid refrigerant existing on the condenser side will be adjusted by the liquid refrigerant accumulated in the tank, and the liquid refrigerant accumulated in the tank and the liquid level on the condenser side will be adjusted. It will be the same as the liquid level. As a result, the constant liquid level on the condenser side, which is a necessary condition for maintaining a constant subcool, can be achieved for a relatively long time. Therefore, the condenser can maintain the liquid refrigerant state in which the desired subcool has been obtained for a long period of time, and exhibits a certain condensation performance. In addition, since the tank adjusts the amount of liquid refrigerant in the condenser, the amount of refrigerant to be managed is increased, and the performance of the condenser does not fluctuate depending on the amount of refrigerant. That is, even if there is slight heat reception or slight pressure loss, the cycle operates stably even with a change in the amount of charged refrigerant, and the cooling performance of the evaporator is also improved. Further, since this condenser is a multi-pass multi-flow type, it has a compact structure as a whole, and can reduce the amount of refrigerant charged in the cycle. , The cycle is also stable.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a capacitor unit according to an embodiment of the present invention, and FIG. 2 is a graph showing a relationship among a Pd value, a tank liquid level, and a subcool amount with respect to a change in a refrigerant charging amount. Parts common to those shown in FIGS. 3 and 4 are denoted by the same reference numerals, and description thereof is partially omitted.

The capacitor 30 shown in FIG. 1 is a compact and high-performance capacitor of a so-called multi-pass type multi-flow type. In the illustrated one, one partition plate 18 is provided on each of the header pipes 11 and 12. The refrigerant that has flowed into the header pipe 11 from the inlet pipe 16 has a plurality of flat tubes 1.
3 and into the header pipe 12, return to the header pipe 11 after making a U-turn, and make a U-turn again to enter the header pipe 12 (hereinafter referred to as the final header portion 12 a) , so-called three-pass. It is of the formula.

[0020] In this embodiment, in communication with the final header portion 12a in which the refrigerant flowing out of the flat tubes 13 a of the final pass is reservoir, and a tank 31 having a predetermined inner volume by a connecting pipe 32. Mounting position of the tank 31 is specifically a bottom position comparable to that of the top of the flat tubes 13 a of the final pass of the tank 31. Here, the number of columns of the flat tubes 13 a of the final pass is about five, all flat tubes 13
Is about 1/4 to 1/5 of the number of columns of 20 to 25. In this way, when the amount of refrigerant on the condenser side decreases, the liquid refrigerant can be positively returned from the tank side to the condenser 30 side by cycle balance.

The tank 31 is provided at its bottom with a discharge pipe 33 for discharging a liquid refrigerant. The other end of the discharge pipe 33 is connected to the inlet of the liquid tank 20.
This discharge pipe 33 is also connected further the other end of the final pass of the flat tubes 13 connecting pipe 34 one end to the header pipe 12 connected to the refrigerant flowing out of a is the reservoir.

[0022] Incidentally, in the interior of the liquid tank 20, the desiccant 22 is provided, the liquid refrigerant reserved in the bottom by an outlet pipe 23 which is suspended to the lower end inserted through the desiccant 22 in the bulging Zhang valve 24 To be led to.

Next, the operation of the above embodiment will be described. When a normal cooling operation is performed, the high-temperature and high-pressure vaporized refrigerant discharged from the compressor flows down while being condensed by the condenser 30, and becomes a liquid refrigerant in a lower region of the condenser 30. Here, the liquid refrigerant is further cooled and a sub-cool is taken. Usually, the subcool is about 5 to 8 degrees. Liquid refrigerant subcooling is taken enters the final header section 12 a, a part of the liquid refrigerant is introduced into the tank 31, the remainder, he Shirubebi the liquid tank 20 from the connecting pipe 34, Rise
It is led to the evaporator through the tension valve 24.

[0024] In this embodiment, since the final header portion 12 a and the tank 31 communicates with the connecting pipe 32, a portion of the liquid refrigerant is accumulated in the tank 31 via the final header section 12 a . Even if the liquid level on the condenser 30 side fluctuates, the liquid refrigerant accumulated in the tank 31 moves through the connection pipe 32 and adjusts the liquid level of the liquid refrigerant present on the condenser side. As a result, the liquid refrigerant accumulated in the tank 31 and the liquid level on the condenser 30 side become the same, and the constant liquid level on the condenser side, which is a necessary condition for maintaining a certain subcool, is achieved for a relatively long time. can do. If the liquid level on the condenser side is stabilized in this way, the condenser can be used as a liquid refrigerant having a desired subcool, and the above-described liquid level adjustment function can maintain such a subcool state for a long time. Can be.
Further, if the amount of refrigerant in the tank 31 fluctuates, the tank itself adjusts the amount of refrigerant, so that the width of management of the amount of refrigerant is increased, and the performance of the condenser does not fluctuate due to the amount of refrigerant. . That is, even if there is slight heat reception or slight pressure loss, the cycle operates stably even with a change in the amount of charged refrigerant, and the cooling performance of the evaporator is also improved.

Further, since the condenser 30 is a multi-pass multi-flow type, it has a compact structure as a whole, and can reduce the amount of refrigerant charged in the cycle. The width is large and the cycle will be stable.

Next, an experiment was conducted to confirm whether or not the tank 31 exhibited its effectiveness. The following results were obtained.

The conditions for this experiment were as follows: the rotation of the compressor was 1500 rpm. p. m The temperature of the wind supplied to the condenser is 40 degrees Celsius, the speed of the wind supplied to the 3 m / s evaporator is 32 degrees Celsius, the humidity is 50%, and the air volume is 8 m ³ / min.

[0028] Pd values with respect to the change of the refrigerant charging amount, the liquid level of the tank, the relationship between the degree of supercooling, shown in FIG. In the conventional condenser (shown by a broken line), the amount of circulating refrigerant increases with an increase in the rotation speed of the compressor, and the condenser 3
The amount of the liquid refrigerant generated within zero increases, and the subcool increases accordingly. As a result, depending on the heat load applied to the evaporator, the amount of superheat (the degree of superheat; heating the refrigerant evaporated by the evaporator to a saturation temperature or higher) decreases, and the refrigerant does not completely evaporate, and is in a state of liquid refrigerant. In some cases, the compressor may return to the compressor, and the compressor may cause liquid compression. Further, in the conventional condenser, the amount of the liquid refrigerant generated inside increases with the increase of the refrigerant amount, and the condensing area decreases, and the discharge pressure of the compressor, that is, the pressure of the refrigerant at the inlet of the condenser (hereinafter, referred to as the pressure) Pd value) increases.

On the other hand, the capacitor 30 of this embodiment
The liquid refrigerant is stored in the tank 31 or the condenser 30 even if the amount of circulating refrigerant increases with an increase in the rotational speed of the compressor (shown by a solid line). Therefore, the subcool amount becomes constant regardless of the rotational speed of the compressor. , the <br/> Rukoto can stably supply the liquid refrigerant take a subcooling the Rise Zhang valve 24. Further, in the condenser of the present embodiment, even if the amount of refrigerant increases, the liquid refrigerant generated inside does not increase because the part is stored in the tank, the condensing area does not decrease, and the inlet of the condenser does not decrease. Pressure of refrigerant in the part (hereinafter Pd value)
Does not grow.

Even if there is a slight heat reception or a slight pressure loss received by the outlet pipe 17 or the like, the refrigerant does not cause a hunting state, the cooling performance of the evaporator is improved, and the cycle stability and the cooling power are secured. Is also preferable.

As described above, in this embodiment, the subcool can maintain a predetermined value even if the condenser is downsized and the performance is high, and the cooling power of the evaporator is maintained at a predetermined value even when the amount of charged refrigerant changes. , And stability is secured as a whole cycle.

The present invention is not limited to only the above-described embodiment, but can be variously modified within the scope of the claims for utility model registration. For example, in the above-described embodiment, the discharge pipe 33 provided at the bottom of the tank 31 is communicated with the liquid tank 20, but the present invention is not limited to this. it may be in communication with the direct Rise Zhang valve 24.

[0033]

As described above, according to the invention] According to the present invention, in a multi-flow type condenser, attach the tank via a connecting pipe to the outlet portion a predetermined position of the header pipe, f
So that the liquid refrigerant does not increase more than the connecting pipe in the pipe.
Then, a part of the refrigerant liquefied in the final pass of the condenser is stored in the tank, and the remaining refrigerant is discharged from the connection pipe connected to the header portion, so that the liquid level of the liquid refrigerant on the condenser side is adjusted. In addition, the liquid level on the condenser side is made constant, a certain condensing performance is exhibited, and a liquid refrigerant state in which a desired subcool has been obtained can be maintained for a long time. Also, since the tank regulates the amount of refrigerant, the amount of refrigerant can be managed in a wider range, and the performance of the condenser does not fluctuate depending on the amount of refrigerant. Operates stably, and the cooling performance of the evaporator also improves. Further, since this condenser is a multi-pass type multi-flow type, the entire structure has a compact structure, and the amount of refrigerant charged in the cycle can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a capacitor unit according to an embodiment of the present invention;

FIG. 2 is a graph showing a relationship between a Pd value, a subcool amount, and a liquid level with respect to a change in a refrigerant charging amount;

FIG. 3 is a perspective view showing a conventional capacitor;

FIG. 4 is a sectional view of FIG.

[Explanation of symbols]

11, 12 ... header pipe, 12a ... last
Header part, 13 ... flat tubes, 13a ... the final path
Flat tube of the scan, 14 ... core part, 16 ... inlet pipe, 18 ... partition plate, 20 ... liquid tank, 31 ... tank, 32 ... connecting pipe, 33 ... discharge tube, 34 ... connecting tube, f ... heat transfer fins.

Claims (3)

(57) [Scope of request for utility model registration] A header section (1) is provided at both ends of a number of flat tubes (13) arranged in parallel with heat transfer fins (f) interposed therebetween.
1, 12) to form a core portion (14), and by providing a partition plate (18) in each of the header portions (11, 12), the heat exchange fluid flowing from the inlet pipe (16) can be removed. In an air conditioner for a vehicle having a multi-pass type multi-flow type condenser that flows down while meandering in the core portion (14) up to the outlet pipe (17), a plurality of rows of flat tubes serving as the final pass are provided. A final header portion (12a) in which the refrigerant flowing out of the pipe (13a) is stored, and a plurality of rows of flat tubes (13a) having a predetermined internal volume and serving as the final path.
Set the bottom so that it is at the same position as the top one.
Communicating location has been a tank (31) by a connecting tube (32), connecting tube and a lower portion of the tank (31) emitting tubes, which emit the refrigerant in (33) and before Symbol final header (12a) (34) A condenser unit for an air conditioner for an automobile, wherein the condenser unit is connected by (34). 2. The automobile according to claim 1, wherein the number of rows of the flat tubes (13a) in the final pass is 1/4 to 1/5 of the number of rows of all the flat tubes (13). Air conditioner condenser unit. 3. The discharge pipe (33) includes a liquid tank (20).
The condenser unit for an air conditioner for a vehicle according to claim 1, wherein the condenser unit communicates with an inlet of the vehicle.