JP2002090007A - Receiver drier for refrigeration cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver drier for a refrigeration cycle capable of discharging a refrigerant containing almost no bubbles and having a wide stable range of the refrigerant to the charged-and-sealed quantity of the refrigerant by reducing the charged-and-sealed quantity of the refrigerant. SOLUTION: Inner tanks 2A-2C having drying agent layers 5 therein are installed within an outer tank 1 having an inlet 7a of a refrigerant discharging path 7 in an inside bottom. An outlet 3b of a refrigerant introduction path 3 is opened higher than the drying agent layer 6, and outflow parts 4b and 9b for the refrigerant passing through the drying agent layer 5 to the outside of the inner tanks 2A-2C are disposed at a position facing an interior of a liquid phase L separated from a gas phase in the outer tank 1. The refrigerant passing through the drying agent layer 5 is made to flow directly into and join the liquid phase separated from the gas phase through the outflow parts 4ba and 9b, and the liquid refrigerant in the liquid phase L is discharged outside through the refrigerant discharging path 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle applied to an air conditioning system such as an air conditioner for an automobile, which receives a refrigerant condensed in a condenser and separates the refrigerant into gas and liquid.
The present invention relates to a receiver dryer for supplying the liquid refrigerant to a next cycle part.

[0002]

2. Description of the Related Art In a receiver cycle, which is a typical type of a refrigeration cycle, as shown in FIG.
P) high-temperature and high-pressure gas refrigerant discharged from the condenser (C)
D), exchanges heat with outside air, cools and condenses and liquefies, flows into a receiver tank (RT) in a gas-liquid mixed state, separates into gas and liquid, and the liquid refrigerant is led out to the expansion valve (EV). Is rapidly decompressed and expanded and introduced into the evaporator (EP) as a low-pressure and low-temperature mist-like refrigerant. In the process of flowing through the evaporator (EP), it takes off latent heat from outside air and evaporates. It exits (EP) and is sucked into the compressor (CP). The satin portion in the figure indicates a liquid refrigerant. The control of the flow rate of the refrigerant is performed by adjusting the opening of the expansion valve (EV) based on a signal from the thermosensitive cylinder (SC) provided on the outlet side of the evaporator (EP).

[0003] The refrigerant condensed in the condenser (CD) has an insufficient degree of supercooling and is in an unstable state in which it is vaporized by a small amount of heat reception or pressure loss on the downstream side. Efficiency reduction and fluctuation are likely to occur. As a countermeasure, a subcooling unit has been provided for supercooling the refrigerant which has been condensed by the condenser (CD) to a temperature lower by about 2 to 5 ° C. than the condensing temperature. The system to send to is adopted. Normally, the subcool section is disposed downstream of the receiver tank (RT). However, the subcool section is often integrated with the condenser (CD) (subcool system condenser) in terms of space efficiency.

On the other hand, as the above-mentioned receiver tank (RT), a receiver dryer having a function of adsorbing and removing moisture mixed in a refrigerant by providing a desiccant-filled layer inside is often used.

[0005] As a typical receiver dryer commonly used in the past, one having a structure as shown in Fig. 9 is known. In the receiver dryer, a dryer unit (41) is loaded in a vertical tank (40), and spaces (42) and (43) are formed above and below the dryer unit (41). It has a structure that rises from the bottom (40a) of (40), passes through the center of the dryer unit (41), and projects into the upper space (42).
The refrigerant in a gas-liquid mixed state is discharged from the outlet (44a) at the top end of the refrigerant introduction pipe (44) into the upper space (42), and the upper perforated plate (45a) and the filter (46a) of the dryer unit (41). And enters the desiccant filling layer (47) through the desiccant filling layer (47), passes through the filter (46b) and the lower perforated plate (46b), enters the lower space (43), and passes through the lower space (43). ), The liquid refrigerant in the liquid pool (P) separated by gas and liquid is discharged from the refrigerant discharge hole (48) opened at the bottom.

[0006]

In air conditioning systems, there are always issues of improving space efficiency and improving performance. Particularly in automotive air conditioners, there is a demand for making the entire system smaller in order to use the limited space of the vehicle body as effectively as possible. Therefore, it is necessary to reduce the amount of refrigerant charged in the refrigeration cycle. On the other hand, it is required to improve the performance stability (overcharge toughness) with respect to load fluctuations and to suppress the performance degradation over time (reduction in leakage toughness) due to continuous running. It is desired to widen the stable region of the refrigerant in the supercooled state with respect to the charged amount.

However, when a charge test (cycle bench) of an automobile air conditioner is performed, in the correlation characteristic diagram between the degree of supercooling of the condensed refrigerant and the amount of charged refrigerant in FIG. Ideally, a sharp steady rise and a wide steady range are obtained as shown by a curve B shown by a virtual line in FIG. 2. However, in a conventional air conditioner for a vehicle using a subcooled system condenser, as shown by a curve A shown by a solid line in FIG. The rise of the curve until the steady range is reached is gradual, and the steady start point shifts toward the side where the amount of charged refrigerant is larger, which causes the refrigerant filling point to be slower and the width of the steady region to be narrower. It recognized. This means that it is difficult to reduce the size of conventional air conditioners for automobiles by reducing the amount of charged refrigerant, and the stability of performance against load fluctuations is poor, and the performance tends to decrease over time due to continuous driving. are doing.

The present inventors first studied from various angles the causes of the above-mentioned problems in the conventional automotive air conditioner in order to realize the miniaturization and high performance of the air conditioning system such as the automotive air conditioner. As a result, a large amount of gas bubbles (gas refrigerant) is mixed in the liquid refrigerant derived from the conventional general-purpose receiver dryer, and as a result, the steady-state region is narrowed, and the steady-state start point is determined by the amount of the charged refrigerant. It turned out that it shifted to the big side.

[0009] Further, when the cause of mixing a large amount of air bubbles into the liquid refrigerant led out of the receiver drier was examined, the flow rate of the refrigerant flowing into the receiver drier is generally large. The refrigerant is discharged from the outlet (44a) of (44) in the form of a fountain, and a large turbulent region of the liquid refrigerant is generated in the upper space (42), whereby a large amount of bubbles are generated and entrapped in the liquid refrigerant. In a state where the entrapped air bubbles are not sufficiently removed, the air bubbles pass through the dryer unit (41) and pass through the lower space (4).
3) In addition to being added to the liquid pool (P) inside, when the liquid refrigerant falls in the gas phase from the lower end of the dryer unit (41), the gas refrigerant is entrained and the potential energy of the falling liquid refrigerant is increased. As a result, the liquid surface of the liquid pool (P), that is, the gas-liquid interface is disturbed, and the disturbance of the gas-liquid interface also generates a large amount of new bubbles, and the liquid refrigerant containing these bubbles is led out from the refrigerant outlet hole (48). It turned out to be.

[0010]

The inventors of the present invention have conducted further detailed experimental studies based on the above findings, and as a result, as a receiver dryer, the refrigerant which has passed through the desiccant packed bed has been separated into a liquid phase and a gas phase. When adopting a specific structure that merges directly into the inside, the generation and entrainment of air bubbles are suppressed, the incorporation of air bubbles into the derived liquid refrigerant is significantly reduced, and thus the refrigerant charging amount of the refrigeration cycle is reduced, In addition, it is possible to widen the stable area of the refrigerant with respect to the amount of the filled refrigerant by maximizing the volume of the receiver dryer, and find that it is particularly applicable to a subcool system condenser such as an air conditioner for an automobile. This led to the invention.

That is, in the receiver dryer for a refrigeration cycle according to the first aspect of the present invention, an inner tank having a desiccant-filled layer inside is loaded into an outer tank having an inlet for a refrigerant outlet passage at an inner bottom portion. The outlet of the introduction path opens higher than the desiccant-filled layer, and has an outflow portion of the refrigerant that has passed through the desiccant-filled layer to the outside of the inner tank, and this outflow portion separates gas and liquid in the outer tank. The liquid-phase separated liquid phase is set at a position facing the liquid phase, and the refrigerant introduced from the outlet of the refrigerant introduction passage passes through the desiccant packed layer and flows out of the outflow portion to the outside of the inner tank. And the liquid refrigerant in the liquid phase is discharged to the outside through the refrigerant discharge passage.

In the receiver dryer having the above-described structure, the refrigerant that has passed through the desiccant-filled layer directly merges into the gas-liquid separated liquid phase. Since the gas refrigerant is not entrained on the way and the turbulence of the gas-liquid interface is suppressed, bubbles are not easily generated even at this interface, and the bubbles are smoothly cut off. Will be derived.

According to a second aspect of the present invention, in the receiver dryer of the first aspect, a desiccant-filled layer in the inner tank is provided between the upper and lower perforated plates, and the refrigerant is introduced into the inner tank space on the upper perforated plate. The outlet of the passage is open, and the lower perforated plate forms the outflow portion to the outside of the inner tank. In this case, the introduced refrigerant is discharged to the upper part in the inner tank, enters the desiccant filling layer from the upper perforated plate, passes through the desiccant filled layer, and is separated into liquid and gas phases from the holes of the lower perforated plate. Although the water flows out, the upper space in the inner tank has a shorter vertical space, so that the generation of bubbles due to the falling energy in this space can be suppressed. The inner tank can adopt a simple form opened downward.

According to a third aspect of the present invention, in the receiver drier of the first aspect, the inside of the outer tank is partitioned into an upper space and a lower space by the inner tank, and the outlet of the refrigerant introduction passage opens in the upper space. Having a porous inflow portion for allowing the refrigerant to flow from the upper space to the inside on the upper side peripheral wall of the inner tank, and the porous outflow portion for allowing the refrigerant to flow out of the inner tank to the lower side peripheral wall of the inner tank. It has a configuration having. In this case, the introduced refrigerant
Released into the upper space of the outer tank, enters the desiccant packed layer through the upper peripheral wall of the inner tank, passes through the desiccant packed layer, and flows out of the lower peripheral wall of the inner tank into the liquid phase separated by gas and liquid. I do. However, when the refrigerant flows into the inner tank, the refrigerant wraps around from above the inner tank to the outer periphery, so that the bubbles entrapped in the liquid refrigerant in the process are easily released, and from the inner tank. Flows out to the side, so that the air bubbles mixed in before reaching the inlet of the refrigerant outlet passage at the inner bottom of the outer tank can easily escape upward.

According to a fourth aspect of the present invention, in the receiver dryer according to any one of the first to third aspects, the refrigerant introduction path includes a refrigerant introduction pipe rising from the bottom of the outer tank and penetrating the desiccant filling layer. The upper end of the tube forms the outlet of the refrigerant introduction path. In this case, since the refrigerant introduction part and the discharge part are both located on the bottom side of the outer tank, connection of the refrigerant flow path with the outside is easy, the external appearance is neat, and the refrigerant introduction pipe supports the inner tank. Available as a department.

According to a fifth aspect of the present invention, in the receiver dryer according to any one of the first to fourth aspects, the inlet of the refrigerant introduction path is connected to the refrigerant outlet of the condenser, and the outlet of the refrigerant discharge path contains the liquid refrigerant. It is connected to the refrigerant inlet of the subcool part to be cooled. In this case, since only the liquid refrigerant can be stably supplied from the receiver dryer to the subcool portion, the subcooling function of the subcool portion is maximized, and a sufficient subcooling region can be secured.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 is a front view of a condensing device equipped with a receiver dryer of a first embodiment according to the present invention,
FIG. 2 is a vertical front view schematically showing the flow of the refrigerant in the condenser, FIG. 3 is a vertical front view of a receiver dryer portion of the condenser, and FIG. 4 is a vertical front view of the receiver dryer of the second embodiment. 5 is a vertical sectional front view showing a modified example of the refrigerant introduction path and the discharge path in the receiver dryer of the present invention, and FIG. 6 is a vertical sectional front view of the receiver dryer of the third embodiment.

In FIG. 1, reference numeral (10) denotes a subcooling system condenser in which a condensing part (C) and a subcooling part (S) are integrated, and is provided between a pair of right and left headers (11a) and (11b) along a vertical direction. A large number of flat heat exchange tubes (12) along the horizontal direction are arranged side by side at predetermined intervals in the up and down direction with their respective ends communicating with both headers (11a) and (11b). ing. Corrugated fins (13) are arranged between the heat exchange tubes (12) ... and outside the outermost heat exchange tubes (12).
Furthermore, outside the outermost heat exchange tube (12), a side plate (14) for protecting corrugated fins (13)
Is provided.

At the same height position on the lower side of both headers (11a) and (11b), a partition member (16) for partitioning the inside of the header is provided. C), and the lower side constitutes a subcool section (S). In the condensing section (C), a large number of heat exchange tubes (12)... Are formed by a plurality of partition members (15) provided at predetermined positions of both headers (11a) (11b). Flow paths (C1) to (C
It is divided into 3). Furthermore, right header (11b)
At the upper end, the condenser inlet (17a), at the lower end, the subcool outlet (18b), at the lower end corresponding to the condenser (C) of the left header (11a), the condenser outlet (17b). A subcool section entrance (18a) is provided at the lower end corresponding to the subcool section (S).

The receiver dryer (RD1) of the first embodiment of the present invention is attached to the subcool system condenser (10) along the left header (11a).

As shown in FIG. 3, the receiver dryer (RD1) of the first embodiment has a short cylindrical inner tank (2) which is opened downward in a vertical cylindrical outer tank (1).
A) is held at an eccentric position via a vertical refrigerant introduction pipe (31). Inside the inner tank (2A), there are spherical desiccant particles (5a) between the upper and lower perforated plates (4a) (4b).
... and a desiccant-filled layer (5) along the center of the inner tank (2A) in the upper space (20) on the upper perforated plate (4a). The upper end of the penetrated refrigerant introduction pipe (31) protrudes. In addition,
(6a) and (6b) are filter layers interposed between the upper and lower perforated plates (4a) and (4b) and the desiccant-filled layer (5), respectively.

In the inner tank (2A), the lower perforated plate (4b) faces the liquid phase (L) of the refrigerant gas-liquid separated in the outer tank (1) in the normal operation state of the refrigeration cycle. The position is set as follows.

The refrigerant introduction pipe (31) has a lower end closely fitted to the upper end opening (32a) of a refrigerant introduction hole (32) formed in the header (1a) at the bottom of the outer tank (1) and is vertically extended. Retained
A refrigerant introduction path (3) is formed together with the refrigerant introduction hole (32), and an upper end opening protruding into the upper space (20) of the inner tank (2A) forms an outlet (3b) of the refrigerant introduction path (3). ing. The inlet (3a) of the refrigerant introduction path (3) is connected to the left header (11) of the subcool system condenser (10).
connected to the condensing section outlet (17b) in a)
The header (1a) is provided with a vertical refrigerant outlet (71) having an inlet (7a) opened at a position away from the upper end opening (32a) of the refrigerant inlet (32). The refrigerant outlet hole (71) and the L-shaped pipe (72) connected to the lower end constitute a refrigerant outlet path (7), and the outlet (7b) of the refrigerant outlet path (7) is a subcooled outlet. It is connected to the subcool part entrance (18a) in the left header (11a) of the system condenser (10).

In the subcooled system condenser having the above configuration, the high-temperature and high-pressure gas refrigerant discharged from the compressor of the refrigeration cycle first flows into the condenser (C) from the condenser inlet (17a) as shown in FIG. Then, in the course of sequentially passing through the first to third flow paths (C1) to (C3), heat exchanges with the outside air to condense, forming a gas-liquid mixed state from the condensing section outlet (17b) to the refrigerant introduction path (3). Through the receiver dryer (R
D1) and the receiver dryer (RD1)
In the subcooling section (S), the liquid refrigerant enters the subcooling section (S) from the subcooling section inlet (18a) through the refrigerant outlet path (7), and further exchanges heat with the outside air in the subcooling section (S) to be in a supercooled state. Is sent to the next cycle part (evaporator side) from the subcool part outlet (18b).

The receiver dryer (RD)
In 1), the refrigerant in a gas-liquid mixed state sent through the refrigerant introduction path (3) flows from the outlet (3b) of the refrigerant introduction path (3) to the upper space (20) of the inner tank (2A). Into the desiccant-filled layer (5) through the upper perforated plate (4a) and the filter layer (6a), and out of the lower perforated plate (4b) through the filter layer (6a). However, since it faces the liquid phase (L) of the gas-liquid separated refrigerant in the lower perforated plate (4b) or the outer tank (1), it joins the liquid refrigerant separated as it is.

Therefore, unlike a conventional general-purpose receiver dryer, the gas refrigerant is not entrained on the way of falling when it falls in the gas phase and reaches the gas-liquid interface, and does not flow out of the lower porous plate (4b). Potential energy is small,
Since the turbulence at the gas-liquid interface is suppressed, bubbles are not easily generated even at this interface, and the bubbles are smoothly cut off. Therefore, the liquid refrigerant containing almost no air bubbles is led out from the refrigerant outlet path (7). Further, in the first embodiment, when the refrigerant in the gas-liquid mixed state is discharged from the outlet (3b) of the refrigerant introduction path (3) into the upper space (20) of the inner tank (2A), the upper space ( Since the vertical interval (a) of (20) is short, the generation of air bubbles due to the falling energy in the upper space (20) is also suppressed, and the mixing of the air bubbles of the liquid refrigerant led out from the refrigerant outlet path (7) is smaller. Become.

In the receiver dryer (RD1) of the first embodiment, since the inner tank (2A) is a short cylinder, a large space is formed on the inner tank (2A) in the outer tank (1). I have. However, the design of the outer shape of the inner tank can be changed in various ways. For example, a vertically elongated cylindrical inner tank (2B) such as a receiver dryer (RD2) of the second embodiment shown in FIG. (2B)
A wide space may be ensured beside the. In addition,
In the receiver dryer (RD2) of the second embodiment, the outlet of the refrigerant that has passed through the desiccant filling layer (5), that is, the lower perforated plate (4b) and the inlet (7a) of the refrigerant outlet path (7).
The desiccant filling layer (5)
By the time the refrigerant that has passed through the air-conditioner moves to the inlet (7a), the air bubbles that have been mixed are easily released upward.

In the receiver dryers (RD1) and (RD2) of the first and second embodiments, the inlet (7) of the refrigerant outlet passage (7) is provided at the flat inner bottom surface of the outer tank (1). It is open at the diameter of the hole (70). However, as for the inlet (7) of the refrigerant outlet passage (7), for example, as shown in FIG. 5 (a), the diameter of the inlet (7) is increased in a trumpet shape toward the inside of the outer tank (1). ), A configuration in which the periphery of the inlet (7) projects conically toward the inside of the outer tank (1) can also be adopted. In addition, refrigerant introduction path (3)
As for the side, in addition to the structure in which the header (1a) of the outer tank (1) and the header (11a) of the capacitor (10) are directly connected as shown in FIG. A) As shown in (b), a connection structure using the same piping as the refrigerant outlet path (7) side can also be adopted.

The receiver dryer (RD3) of the third embodiment shown in FIG. 6 is provided in a vertical cylindrical outer tank (1).
A substantially cylindrical inner tank (2
C) are concentrically loaded, and the inside of the outer tank (1) is divided into an upper space (8a) and a lower space (8b) by a flange portion (21) provided on the outer periphery of the inner tank (2C). A refrigerant inlet pipe (31) rising from the center of the inner bottom of the outer tank (1) penetrates the entire inner tank (2C) and projects into the upper space (8a). In addition, the header (1a) at the bottom of the outer tank (1) has the above-mentioned FIG.
The refrigerant introduction path (3) and the refrigerant discharge path (7) having a structure for connecting to the outside by piping in the same manner as those exemplified in (1).
The refrigerant introduction passage (3) is provided with a refrigerant introduction pipe (3).
While communicating with the lower end of (1), the inlet (7a) of the refrigerant outlet passage (7) has a trumpet-shaped opening toward the inside of the outer tank (1).

The inner tank (2C) has a large-diameter upper cup (22) and a small-diameter lower cup (23), both of which form a hat with a flange.
With the opening side facing each other and the periphery of the filter layer (6c) sandwiched between the two flanges, and a porous inflow portion at the lower side of the peripheral wall (22a) of the upper cup (22). (9a) and a porous outflow portion (9b) on the lower side of the peripheral wall portion (23a) of the lower cup (23). Thus, the outlet (9b) of the lower cup (23)
In the steady state of the refrigeration cycle, the outer tank (1)
Liquid phase (L) of gas-liquid separated refrigerant in lower space (8b)
It is set to face inside. The filter layer (6c) is disposed so as to be in contact with the entire inner surface of the lower cup (23).

In the receiver dryer (RD3) of the third embodiment, the refrigerant in a gas-liquid mixed state introduced from the refrigerant introduction passage (3) is supplied to the upper space (8a) of the outer tank (1).
Into the porous inlet (9) of the upper cup (22).
a) enters the inner tank (2C), passes through the desiccant-filled layer (5), and flows out of the outlet (9b) of the lower cup (23) into the lower space (8b) of the outer tank (1). However, since the outflow portion (9b) faces the liquid phase (L) of the refrigerant that has been gas-liquid separated in the lower space (8b), it merges with the liquid refrigerant that has been gas-liquid separated. Therefore, as in the case of the receiver dryers (RD1) and (RD2) of the first and second embodiments, the entrainment of gas refrigerant as in the case of falling in the gas phase and reaching the gas-liquid interface does not occur, and the potential energy does not increase. This suppresses the turbulence of the gas-liquid interface due to air bubbles, so that air bubbles are hardly generated even at this interface, and the bubbles are smoothly cut off. Thus, the refrigerant is led out of the refrigerant outlet path (7) as a liquid refrigerant containing almost no air bubbles.

Further, in the third embodiment, when the refrigerant discharged from the outlet (3b) of the refrigerant introduction path (3) into the upper space (8a) flows into the inner tank (2C), the refrigerant flows into the inflow portion (9).
Since a) is located on the lower side of the peripheral wall portion (22a) of the upper cup (22), it goes around from the upper portion of the inner tank (2C) to the lower portion of the outer periphery. Since the trapped bubbles are released, the amount of gas refrigerant accompanying the liquid refrigerant flowing into the inner tank (2C) is extremely reduced. Also, since the refrigerant flows out from the outflow portion (9b) of the inner tank (2C) to the side, it reaches the inlet (7a) of the refrigerant outlet passage (7) at the inner bottom of the outer tank (1). Also, the small air bubbles that have been mixed are easily evacuated upward, so that the liquid refrigerant drawn out from the refrigerant outlet path (7) has less air bubbles mixed therein.

Thus, the receiver dryer (RD)
1) to (RD3), in the subcooling section (S) to which the liquid refrigerant containing almost no air bubbles is supplied, the supercooling function can be maximized, so that a sufficient subcooling area can be secured. In addition, these receiver dryers (RD1) to (RD1)
In the refrigeration cycle using 3), the amount of charged refrigerant can be set to an appropriate amount at an early stage, and a surplus space in the outer tank (1) is used as a buffer space to allow excess refrigerant from an optimum refrigerant point. Since the stable range up to the point can be expanded, very stable operation can be performed, and the operating pressure of the refrigeration cycle can be suppressed low, so that the required power is also reduced and the coefficient of performance of the system can be expected to be improved.

The above operation can be described in terms of the correlation between the degree of supercooling of the condensed refrigerant and the amount of charged refrigerant in the charge test shown in FIG. 8 described above. Reaches a steady starting point on the smaller side of
This means that the width of the steady area becomes wider, which means that the curve approaches an ideal curve B indicated by a virtual line in the figure. Therefore, in the automotive air conditioner using this condensing device, it is easy to reduce the size of the air conditioner by reducing the amount of charged refrigerant, improve the stability of performance against load fluctuations, and reduce the performance over time due to continuous running. Can be suppressed.

The inner tank in the receiver drier of the present invention can have various shapes and structures other than those exemplified in the first to third embodiments, and has permeated the desiccant filling layer (5). The outflow part that allows the refrigerant to flow into the outer tank can be variously configured other than the example. In addition, instead of using the refrigerant introduction pipe (31) rising from the bottom of the outer tank (1) as in the above embodiment, the refrigerant introduction path (3) is connected from the outside to the upper part of the outer tank (1). Accordingly, a configuration in which the refrigerant is introduced into the upper space (20) of the inner tanks (2A) and (2B) in the first and second embodiments and the upper space (8a) of the outer tank (1) in the third embodiment can be adopted. It is. However, in the configuration using the refrigerant introduction pipe (31) as in the first to third embodiments, since the refrigerant introduction part and the discharge part in the outer tank (1) are both on the tank bottom side, the refrigerant flow path to the outside is provided. Is easy to connect, the overall appearance is clear and the appearance is good,
Also, the refrigerant introduction pipe (31) can be used as a support for the inner tank.

Further, the receiver dryer of the present invention is particularly suitable for a refrigeration cycle having a subcool section on the condensing side as illustrated, but can also be applied to various refrigeration cycles without a subcool section. The subcool unit is not limited to a structure integrated with a condenser like the exemplified subcool system condenser, but may be an independent heat exchanger incorporated in a refrigeration cycle. In addition to the so-called multi-flow type condenser illustrated in FIG. 1, there are various types of condensers such as a condenser using a serpentine tube as a heat exchange pipe.

[0037]

According to the first aspect of the present invention, a receiver dryer for a refrigeration cycle is provided with an inner tank provided with a desiccant-filled layer on the inside, and a refrigerant that has passed through the desiccant-filled layer flows out of the inner tank. Since it is made to merge into the liquid phase of the refrigerant gas-liquid separated in the outer tank, the generation and entrainment of air bubbles are suppressed, and the gas refrigerant at the gas-liquid interface is smoothed out of the gas bubbles and derived. It is possible to significantly reduce the amount of air bubbles mixed into the liquid refrigerant, thereby reducing the amount of refrigerant charged in the refrigeration cycle, and maximizing the capacity of the receiver drier to expand the stable region of the refrigerant with respect to the amount of refrigerant charged. In particular, there are provided those excellent in applicability to subcool system capacitors such as air conditioners for automobiles.

According to the second aspect of the present invention, in the above receiver dryer, a desiccant filling layer is provided between the upper and lower perforated plates, and the refrigerant discharged into the upper portion of the inner tank is filled with the desiccant from the upper perforated plate. The gas enters the layer and flows out into the liquid phase that has been gas-liquid separated using the lower perforated plate as the outflow portion.However, the generation of air bubbles due to the falling energy in the upper space in the inner tank is suppressed, and the air bubbles in the liquid refrigerant derived from There is an advantage that the mixing of the inner tank is reduced and the structure of the inner tank is simplified.

According to the third aspect of the present invention, in the receiver dryer, the inside of the outer tank is partitioned into an upper space and a lower space by the inner tank, and the introduced refrigerant is discharged into the upper space of the outer tank. Bubbles entrapped in the liquid refrigerant while entering the desiccant packed layer from the upper peripheral wall of the inner tank and flowing out of the liquid phase separated from the lower peripheral wall into the gas phase, but flowing into the inner tank Are easily released, and the air bubbles that have been mixed in the process of flowing out of the inner tank to the side and reaching the inlet of the refrigerant outlet path are easily released upward, so that the mixing of air bubbles in the derived liquid refrigerant is more likely. Less.

According to the fourth aspect of the present invention, in the above receiver dryer, the refrigerant introduction path is formed by a refrigerant introduction pipe rising from the bottom of the outer tank and penetrating the desiccant filling layer, and the upper end of the refrigerant introduction pipe is formed by the refrigerant introduction pipe. Since the outlet of the introduction path is formed, both the refrigerant introduction part and the refrigerant discharge part are located on the bottom side of the outer tank, so that the connection of the refrigerant flow path with the outside is easy, and the overall appearance is clean and the refrigerant introduction pipe is provided. Can be used as a support for the inner tank.

According to the fifth aspect of the present invention, in the receiver dryer described above, the inlet of the refrigerant introduction path is connected to the refrigerant outlet of the condenser, and the outlet of the refrigerant outlet path is the refrigerant inlet of the subcool section for supercooling the liquid refrigerant. Since the subcooler can be supplied with only the liquid refrigerant stably from the receiver dryer to the subcooler, the subcooler has the advantage that the supercooling function can be maximized to secure a sufficient subcooling region.

[Brief description of the drawings]

FIG. 1 is a front view of a condenser equipped with a receiver dryer according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional front view schematically showing a flow of a refrigerant in the condensing device.

FIG. 3 is a vertical sectional front view of a receiver dryer portion of the condensing device.

FIG. 4 is a longitudinal sectional front view of a receiver dryer according to a second embodiment of the present invention.

FIG. 5 shows a modified example of the refrigerant introduction path and the discharge path in the receiver dryer of the present invention. FIG. 5 (a) is a vertical sectional front view of a main part having a shape in which the inlet of the refrigerant discharge path is enlarged in a trumpet shape. (B) The figure is a longitudinal sectional front view of the main part of the configuration in which the periphery of the inlet of the refrigerant outlet passage protrudes in a conical shape.

FIG. 6 is a vertical sectional front view of a receiver dryer according to a third embodiment of the present invention.

FIG. 7 is a refrigerant circuit diagram of a receiver cycle.

FIG. 8 is a graph showing the correlation between the degree of supercooling of the condensed refrigerant and the amount of refrigerant charged.

FIG. 9 is a vertical sectional front view of a conventional general-purpose receiver dryer.

[Explanation of symbols]

 1 outer tank 2A to 2C inner tank 20 upper space of inner tank 21 flange 22a peripheral wall (upper peripheral wall) 22b ..Peripheral wall (lower side peripheral wall) 3... Refrigerant introduction path 3a... Inlet 3b... Outlet 31... Refrigerant introduction pipe 4a. Plate 4b Lower perforated plate (outflow portion) 5 Desiccant-filled layer 7 Refrigerant outlet 7a Inlet 7b Outlet 8a · · · · · · Upper space of outer tank 8a · · · · · Lower space of outer tank 9a · · · · · Inflow section 9b · · · · · Outflow section 10 · · · · · Subcool system condenser 17b · · · ·・ Condenser outlet 18a ・ ・ ・ Subcooler inlet RD1-RD3 ・ ・ ・ Receiver dryer C ・ ・ ・And condensation unit S ······ subcooler L ······ liquid phase

Claims (5)

[Claims] 1. An inner tank having a desiccant-filled layer inside is loaded into an outer tank having an inlet for a refrigerant discharge passage at an inner bottom portion, and an outlet of the refrigerant introduction passage is opened higher than the desiccant-filled layer. And an outlet for the refrigerant that has passed through the desiccant-filled layer to the outside of the inner tank. The outlet is set at a position facing the gas-liquid separated liquid phase in the outer tank. When the refrigerant introduced from the outlet passes through the desiccant packed layer and flows out of the outflow portion to the outside of the inner tank, the refrigerant directly merges into the gas-liquid separated liquid phase. A refrigeration cycle receiver dryer configured to be discharged to the outside through a refrigerant discharge passage. 2. A desiccant-filled layer in an inner tank is provided between upper and lower perforated plates, an outlet of a refrigerant introduction passage is opened in a space in the inner tank on the upper perforated plate, and a lower perforated plate is connected to the inner tank. The receiver dryer for a refrigeration cycle according to claim 1, wherein the outlet portion forms the outflow portion to the outside. 3. The inside of the outer tank is partitioned into an upper space and a lower space by the inner tank, and an outlet of the refrigerant introduction passage is opened in the upper space, while the upper side peripheral wall of the inner tank is formed from the upper space to the inside. 2. The refrigeration cycle receiver dryer according to claim 1, further comprising a porous inflow portion through which the refrigerant flows, and the porous outflow portion through which the refrigerant flows out of the inner tank on a lower peripheral wall of the inner tank. . 4. The refrigerant introduction path comprises a refrigerant introduction pipe rising from the bottom of the outer tank and penetrating the desiccant filling layer, and the upper end of the refrigerant introduction pipe forms an outlet of the refrigerant introduction path.
4. The receiver dryer for a refrigeration cycle according to any one of claims 1 to 3. 5. The refrigerant inlet path is connected to a refrigerant outlet of a condenser, and the refrigerant outlet path is connected to a refrigerant inlet of a subcooler for supercooling a liquid refrigerant.
4. The receiver dryer for a refrigeration cycle according to any one of 4.