JP2588846Y2 - 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 condenser unit for an air conditioner for an automobile, in which a multi-pass type multi-flow condenser and a liquid tank are connected by a connecting pipe.

[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]

However, the condenser unit of the air conditioner for a vehicle is composed of a condenser and the condenser unit.
I and a liquid tank provided in the vicinity of the capacitor
Ri, the capacitor, the miniaturization and high performance of the entire shape
A so-called multi-pass type in order to achieve, the refrigerant within the condenser is allowed to flow while U-turn.

As shown in FIGS. 4 and 5, 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 are parallel to each other and the header pipes 11,
The heat transfer fins f are interposed between the flat tubes 13 to form a core portion. The header pipes 11 and 12 have lids 1 at both ends.
The one header pipe 11 is provided with an inlet pipe 16 through which the refrigerant flows, and the other header pipe 12 is provided with an outlet pipe 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 into the plurality of rows of flat tubes 13, and flows in a meandering manner in the core 14. , From 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. 5, the liquid tank 20 is, as shown in FIG. 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 protection of the global environment. Therefore, the amount of refrigerant used has been reduced for air conditioners for automobiles.

However, when a small amount of refrigerant flows using the above-described high-performance condenser, the state of the refrigerant in the condenser fluctuates even with a slight fluctuation in the heat load, and the cooling in which a predetermined subcool (supercooling) is obtained. Driving is not performed stably, and there is a possibility that the temperature of the air discharged from the vehicle interior may fluctuate. For example, when the amount of charged refrigerant is close to or slightly smaller than appropriate, the refrigerant only liquefies at the outlet of the condenser, and a sufficient subcooling cannot be obtained. Therefore, the refrigerant in the condenser
The gas-liquid mixture is in a saturated state, and is in an unstable state in which the refrigerant gasifies due to slight heat reception and pressure loss received by the outlet pipe and the like.

[0011] 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 as a liquid refrigerant up to a portion (hereinafter referred to as a final pass) which becomes a final circulation path after the refrigerant meanders in the condenser and circulates in the liquid tank. 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.

[0013] However, this state is a one-point condition, and if the refrigerant is reduced even a little, it 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.

When the performance of the condenser having different performances 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 over-filled 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 overfilled to some extent, and 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 is also taken into consideration to setting a predetermined subcooled in condenser, taken subcooling of (supercooled) to Rise Zhang valve The liquid refrigerant cannot be supplied stably, and it is difficult to ensure the stability of the cycle and the cooling power, and there is a possibility that the temperature of the air blown out of the vehicle 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 allows a condenser to always set a desired subcool regardless of fluctuations in the amount of charged refrigerant while using a high-performance and compact condenser. As described above, it is an object of the present invention to provide a condenser unit of an air conditioner for an automobile, which has a large management width of a refrigerant amount and can secure a stable cycle and a sufficient cooling power.

[0017]

The present invention for achieving the above object is achieved by providing header sections at both ends of a large number of flat tubes arranged side by side with heat transfer fins interposed therebetween. A multi-pass multi-flow type in which a core portion is formed, and a heat exchange fluid flowing from an inlet pipe flows down while meandering in the core section until reaching an outlet pipe by providing a partition plate in each of the header portions. and the capacitor leads to lower chamber through the by reserving the leaked refrigerant to the upper chamber desiccant <br/> from the condenser, a liquid tank for a liquid refrigerant to flow out to the outside from the conduit communicating with the the lower chamber And the cold water flowing out of a plurality of rows of the flat tubes as a final pass.
The final header portion where the medium is stored and the liquid tank
In the capacitor unit of an automotive air conditioning apparatus formed by connecting the said final header portion with the upper chamber having a predetermined inner volume of the liquid tank, it communicates the lower portion area of the final header portion by a first connecting pipe the upper portion area of the upper chamber of the liquid tank communicated with the second connecting pipe,
The bottom of the upper chamber of the liquid tank is the final pass
A condenser unit for an air conditioner for a vehicle, wherein the condenser unit is located at a position substantially equal to the position of the uppermost one of the flat tubes .

The flat tube communicated with the final header section is
The number of rows is preferably １ ／ to ５ of the number of rows of all flat tubes.

[0019]

In the condenser unit of the automotive air conditioner according to the present invention, the refrigerant liquefied by the condenser has a part connected to the first connection pipe which communicates with the upper part of the final header. Flowing out through the upper portion of the liquid tank to prevent the liquid level in the condenser from rising above the position where the first connection pipe is attached, to keep the liquid level in the condenser constant, A predetermined subcool is taken, and most of the remaining refrigerant in the final header portion has a predetermined subcool.
The liquid flows directly from the second connection pipe connected to the lower part of the final header part into the upper chamber of the liquid tank. In addition, the second connection pipe returns the refrigerant to the inside of the condenser when the liquid level in the condenser drops, and keeps the liquid level in the condenser constant. As a result, the liquid level on the condenser side, which is a necessary condition for maintaining a constant subcool, can be achieved for a relatively long time, and the condenser exhibits a constant condensation performance and has a desired condensation performance. The subcooled liquid refrigerant state can be provided for a long time, and the upper chamber of the liquid tank regulates the amount of refrigerant. The performance does not fluctuate. 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. In addition, 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. , The cycle is also stable.

[0020]

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. FIG. 2 is a diagram showing the temperature of an evaporator, the temperature of a liquid refrigerant on a desiccant,
It is a graph which shows the relationship with d value and subcool amount. Parts common to those shown in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof is partially omitted.

The capacitor 30 shown in FIG. 1 is a small 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.

[0022] In this embodiment, a lower area of a final header portion 12a refrigerant flowing out of the flat tubes 13a of the final pass is reservoir, and a lower portion of the upper chamber 32 having a predetermined inner volume in the liquid tank 31 a communicates over part regions of the final header portions 12a and the upper chamber 32 of the liquid tank 31 by the second connecting pipe 34 communicated with the first connecting pipe 33. Further, the mounting position of the liquid tank 31 is, specifically, a position where the bottom of the upper chamber 32 of the liquid tank 31 is substantially the same as the uppermost one in the flat tube 13a of the final pass. Here, the number of rows of the flat tubes 13a in the final pass is 5
The number of the flat tubes 13 is about 1/4 to 1/5, which is the number of rows of the flat tubes 13.

The lower chamber 3 of the liquid tank 31
Within 5, desiccant 22 is provided, so that liquid refrigerant reservoir in the lower chamber 35 by the outlet pipe 23, which is suspended to the lower end inserted through the desiccant 22 is guided to the Rise Zhang valve 24 ing.

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. The subcooled liquid refrigerant enters the final header section 12a, and a part of the liquid refrigerant is guided to the upper chamber 32 of the liquid tank 31 by the first connection pipe 33, and the rest is connected to the second connection pipe.
After being guided to the upper chamber 32 of the liquid tank 20 by the pipe 34 and passing through the desiccant 22, the liquid tank 31
Drawn by the lower chamber 35 from the outlet pipe 23, it is guided to the evaporator through the bulging Zhang valve 24.

The bottom of the upper chamber 32 of the liquid tank 31 is located at the same position as the top of the flat tube 13 in the final pass . In the present embodiment, since the upper chamber 32 of the liquid tank 31 is connected to the upper part of the final header 12a, a part of the liquid refrigerant in the final header 12a is:
Upper chamber 3 of the liquid tank 31 through the second connecting pipe 3 4
2 is stored. Therefore, the liquid level in the condenser 30 are not equal to above the position where the second connecting pipe 3 4 are connected, the liquid level is constant. As a result, during normal operation, the liquid refrigerant accumulated in the final header portion 12a and the condenser 30
The liquid level on the side is the same, and this state can be maintained for a relatively long time.

When the liquid level on the condenser side is stabilized, the liquid refrigerant present in the final path of the condenser 30 is further cooled, and can be converted into a liquid refrigerant having a certain subcool. Such a state can be continued for a long time by the liquid level adjusting function.

Also, the amount of refrigerant in the cooling cycle fluctuates,
When the amount becomes low, the liquid refrigerant flows from the upper chamber 32 of the liquid tank 31 to the condenser 30 due to the cycle balance.
And the liquid level on the condenser side is also stabilized.

As described above, since the upper chamber 32 of the liquid tank 31 adjusts the amount of the refrigerant, the width of the amount of the refrigerant to be managed is increased, and the performance of the condenser does not fluctuate depending on the amount of the 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 type 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 performed to confirm whether or not the upper chamber 32 of the liquid tank 31 exhibited the effectiveness against the change in the amount of the refrigerant, and the following results were obtained.

The conditions of this experiment were as follows. 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.

The temperature of the evaporator with respect to a change in the refrigerant charging amount, the temperature of the liquid refrigerant on the desiccant, Pd values, the relationship between the degree of supercooling is as shown in FIG. In a conventional condenser (indicated by a broken line), the amount of liquid refrigerant generated in the condenser 30 increases as the amount of circulating refrigerant 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 liquid refrigerant generated inside increases as the refrigerant amount increases, the condensing area decreases, and the discharge pressure of the compressor, that is, the refrigerant at the inlet of the condenser, The pressure (hereinafter, Pd value) increases.

On the other hand, this embodiment (shown by a solid line)
Even if the amount of circulating refrigerant increases, the liquid refrigerant remains in the liquid tank 31.
For accumulated in the upper chamber 32 or the capacitor 30, degree of supercooling is substantially constant, the Rukoto can stably supply the liquid refrigerant take a subcooling the Rise Zhang valve 24. Further, since the liquid refrigerant in the condenser does not increase and is constant, the condensing area does not decrease and the pressure of the refrigerant at the inlet of the condenser (hereinafter referred to as Pd value) does not increase.

As a result of examining the amount of the liquid refrigerant on the desiccant in the liquid tank, it has been found that from the empty state to the full state, the refrigerant is proportional to the increase of the refrigerant, and that the normal refrigerant management can be performed. In addition, it was found that the temperature of the evaporator was constant irrespective of the change of the refrigerant even when the temperature of the evaporator was examined.

Even if there is a slight heat reception or a slight pressure loss received by the outlet pipe 17 and the like, the refrigerant does not hunt, 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 miniaturized and has a high performance. , And stability is secured as a whole cycle.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the claims for utility model registration. For example, the above-described embodiment has the second
While you are connected directly to the final header portion 12a of the connecting pipe 34 from the outside, in some cases, as indicated by a broken line in FIG. 1,
The inside of the header pipe 12 may be inserted and connected to the liquid tank 31.

FIG. 3 shows another embodiment of the present invention, in which an upper chamber 32 and a lower chamber 35 of a liquid tank 31 are separated. This is also the same effect as the above embodiment. Note that reference numeral “36” in the figure denotes an evaporator and “3”.
7 "is a compressor.

[0040]

As described above, according to the invention] According to the present invention, the upper portion of the liquid tank in which the refrigerant flowing out of the flat tubes of the multi-flow type condenser has a lower portion region and a predetermined internal volume of the final header portion which is the reservoir since the chamber communicating with the upper chamber of the liquid tank and the upper part area of the header portion by a second connecting pipe communicated with the first connecting pipe, the liquid level in the condenser is constant, the desired subcooling The obtained liquid refrigerant state can be provided for a long time, and the upper chamber of the liquid tank regulates the management of the refrigerant amount. As a result, the management width of the refrigerant amount is increased, and the performance of the condenser does not fluctuate depending on the amount of the refrigerant amount.
Even if there is a small amount of heat reception or a 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 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 temperature of an evaporator, a temperature of a liquid refrigerant on a desiccant, a Pd value, and a subcool amount with respect to a change in a refrigerant charging amount;

FIG. 3 is a schematic view showing another embodiment of the present invention;

FIG. 4 is a perspective view showing a conventional capacitor unit;

FIG. 5 is a sectional view of FIG. 4;

[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 22 ... drying material, 23 ... guide pipe, 30 ... capacitor, 31 ... liquid tank, 32 ... upper chamber, 33 ... first connecting pipe , 34 ... second connection
Tube , 35: Lower chamber, f: Heat transfer fin.

Claims (2)

(57) [Scope of request for utility model registration] 1. A header section is provided at each end of a plurality of rows of flat tubes (13) arranged in parallel with heat transfer fins (f) interposed therebetween.
(11, 12) to form a core portion (14), and by providing a partition plate (18) in each of the header portions (11, 12), a heat exchange fluid flowing from an inlet pipe (16). And a multi-pass type multi-flow type condenser (30) that flows down while meandering in the core part (14) until reaching the outlet pipe (17), and the refrigerant flowing out of the condenser (30) is supplied to the upper chamber. (32), pass through the desiccant (22) and lead to the lower chamber (35).
A liquid tank (31) for allowing the liquid refrigerant to flow out of the conduit (23) communicating with the (35), and
To the final location where the refrigerant flowing out of the flat tube (13) is stored.
Head (12a) and the liquid tank (31).
That in the condenser unit of an automotive air conditioner, the upper chamber having a predetermined internal volume of the liquid tank (31)
(32), wherein said final header portion communicated with the final header portion first connecting pipe and a lower portion area of (12a) (33) of (12a)
Wherein an upper portion area upper chamber of the liquid tank (31) and (32) second
Communicated by a connecting tube (34), said bottom of the upper chamber of the liquid tank (31) (32), the last path
Position similar to the top of the flat tube (13)
Capacitor unit of an automotive air conditioning system is characterized in that as a. Wherein said final header portion (12a) Bian <br/> Tairakan (1 3a) communicating with the the number of columns of 1/4 to 1 of the number of columns all the flat tubes (13)
The condenser unit for an air conditioner for a vehicle according to claim 1, wherein the capacitor unit is set to / 5.