JPH0564675U - Liquid tank - Google Patents

Abstract

(57) [Summary] [Purpose] When the cooling cycle is started, the lubricating oil that has accumulated in the liquid tank is quickly returned to the compressor to prevent malfunction of the compressor and to prevent clogging of the desiccant filling section. To provide a "liquid tank" capable of suppressing depressurization boiling of the refrigerant and preventing the cooling capacity from decreasing even when the pressure loss is increased. [Configuration] The refrigerant inflow chamber 41 and the refrigerant storage chamber 42 are communicated with each other. A pressure equalizing tube 43 is provided in the desiccant filling section 30. Further, the refrigerant inflow port 44 of the pressure equalizing pipe 43 facing the refrigerant inflow chamber 41 is formed at a predetermined height above the desiccant filling section 30. [Effect] Even when the desiccant filling part is completely clogged,
Since the flow of the refrigerant can be secured to some extent via the pressure equalizing pipe, it is possible to prevent clogging of the liquid tank.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a liquid tank incorporated in an automobile air conditioner or the like.

[0002]

[Prior Art]

 Generally, an air conditioner for a vehicle has a liquid tank for storing excess refrigerant in the cooling cycle, separating gas and liquid, or removing water and dust.

For example, as shown in FIG. 4, a conventional liquid tank 1 disclosed in Japanese Utility Model Laid-Open No. 52566/1990 has a bottomed cylindrical tank main body 2 and an upper opening of the tank main body 2. 3 has a head portion 4 for closing the same.

A refrigerant inlet portion 5 and a refrigerant outlet portion 6 are formed in the head portion 4. The refrigerant inlet portion 5 has one end connected to an inlet conduit 16 communicating with a condenser and the other end connected to a tank. It is a passage that communicates with the internal space of the main body 2. Further, the refrigerant outlet portion 6 is an L-shaped passage to which an outlet conduit 17 connected to an expansion valve (not shown) is connected to one end and a refrigerant outlet pipe 7 is attached to the other end. The refrigerant outlet pipe 7 hangs down to near the bottom 2c of the tank main body 2 in order to take out only the liquid refrigerant stored in the bottom 2c of the tank main body 2. Further, a sight glass 8 for visually observing the flow state of the refrigerant in the refrigerant outlet portion 6 is provided above the refrigerant outlet pipe 7, and a drying medium in which the refrigerant flows is provided in an intermediate portion of the refrigerant outlet pipe 7. An agent filling section 9 is provided.

The desiccant filling section 9 has an upper support plate 11 and a lower support plate 12 each having a large number of small holes 10, and between the support plates 11 and 12, the desiccant 14 and A filter 15 made of glass wool or the like is housed so as to be wrapped by the lower support plate 12.

The refrigerant flowing from the refrigerant inlet portion 5 of the head portion 4 into the tank main body portion 2 and being in a gas-liquid mixed state adsorbs moisture in the refrigerant by the desiccant 14 while flowing through the desiccant filling portion 9. To be done. Further, the filter 15 removes dust and foreign matter contained in the refrigerant circulating in the cooling cycle. At the same time, the refrigerant in the gas-liquid mixed state that has flowed into the tank main body 2 is separated into gas and liquid before flowing into the desiccant filling section 9 or after flowing into the desiccant filling section 9, and the liquid refrigerant becomes the tank main body. It is stored in the bottom portion 2c of the portion 2. The liquid refrigerant stored in the lower portion of the tank main body 2 passes through the refrigerant outlet pipe 7 provided through the desiccant filling portion 9, and from the refrigerant outlet 6 of the head portion 4 through the outlet conduit 17. Guided to the expansion valve.

[0007]

[Problems to be solved by the device]

 By the way, when the operation of the cooling cycle is stopped and the pressure in the cycle reaches an equilibrium state, the refrigerant filled in the cycle is stored as a liquid refrigerant in a condenser, a liquid tank or the like. In addition, since the lubricating oil used in the compressor is also mixed with the refrigerant and circulates in the cycle, when the operation of the cooling cycle stops, this lubricating oil is also taken out from the compressor and the liquid refrigerant in the liquid tank. It will dissolve in and accumulate.

Therefore, when starting the cooling cycle, the compressor is started in a state where the lubricating oil is less than in the steady state. If the compressor is operated for a long time under such a condition that the amount of lubricating oil is small, the sliding member such as the piston may not operate smoothly, which may cause a malfunction of the compressor. In order to prevent such problems, it is necessary to quickly return the lubricating oil accumulated in the liquid tank to the compressor when the cooling cycle is started.

Further, when the operation of the cooling cycle is continued, the desiccant filling section 9 may be clogged, and at this time, the flow resistance of the refrigerant increases and the pressure loss in the desiccant filling section 9 increases. When the pressure loss in the desiccant filling section 9 increases and it becomes difficult for the liquid refrigerant to collect in the bottom portion 2c of the tank main body 2, the liquid refrigerant is constantly taken out by the refrigerant take-out pipe 7. The refrigerant stored in 2c may boil under reduced pressure. When such a reduced pressure boiling of the refrigerant occurs, the evaporation pressure of the refrigerant in the evaporator rises, so that there is a problem that the cooling capacity significantly decreases.

The present invention has been made in view of such a problem, and when the cooling cycle is started, the lubricating oil accumulated in the liquid tank is quickly returned to the compressor to prevent the malfunction of the compressor from occurring. Another object of the present invention is to provide a liquid tank capable of suppressing the reduced pressure boiling of the refrigerant and preventing the cooling capacity from decreasing even when the pressure loss is increased due to the clogging of the desiccant filling portion.

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is directed to a tank body, a head portion that closes an upper opening of the tank body, and a refrigerant that flows from a refrigerant inlet portion of the head portion through the inner portion. A desiccant filling section, and a refrigerant take-out pipe connected to the desiccant filling section so that the liquid refrigerant stored in the lower portion of the tank main body flows out through the refrigerant take-out port of the head section. In the liquid tank, the refrigerant inflow chamber into which the refrigerant from the refrigerant inlet section flows and the refrigerant storage chamber in which the liquid refrigerant is stored are partitioned and formed in the tank main body section by the desiccant filling section. A pressure equalizing pipe that communicates the inflow chamber and the cooling medium storage chamber is provided in the desiccant filling section, and a refrigerant inlet port of the pressure equalizing tube facing the refrigerant inflow chamber has a predetermined height above the desiccant filling section. Specially formed Is a rich-kid tank to be.

[0012]

[Action]

 When the cooling cycle is started, the lubricating oil that has been dissolved and accumulated in the liquid refrigerant in the refrigerant inflow chamber is taken into the pressure equalizing pipe from the refrigerant inflow port together with the liquid refrigerant, bypasses the desiccant filling section, and flows down. It is quickly taken out by the refrigerant take-out pipe. Therefore, the lubricating oil that has accumulated in the liquid tank when the cooling cycle is stopped is quickly returned to the compressor, which prevents the malfunction of the compressor from occurring. Even when the desiccant filling section is clogged and the pressure loss in the desiccant filling section increases, the pressure equalizing pipe communicates the refrigerant inflow chamber and the refrigerant storage chamber to equalize the pressure, and the refrigerant storage chamber is equalized. The reduced pressure boiling of the refrigerant is suppressed. For this reason, the evaporation pressure of the refrigerant does not rise and the cooling capacity is prevented from decreasing. Furthermore, even when the desiccant filling part is completely clogged, the flow of the refrigerant can be secured to some extent through the pressure equalizing pipe, so this pressure equalizing pipe also has the function of preventing clogging of the liquid tank. To do.

Further, since the refrigerant inlet port of the bypass passage is formed above the desiccant filling portion, when the desiccant filling portion is not clogged, the liquid refrigerant in the refrigerant inflow chamber is bypassed. It rarely flows out into the refrigerant storage chamber through the passage.

[0014]

【Example】

 An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged vertical sectional view showing an essential part of the embodiment.

As shown in FIG. 1, the liquid tank 20 according to the present embodiment has a bottomed cylindrical tank body portion 2 and a head portion 4 that closes an upper opening 3 of the tank body portion 2. The gas-liquid mixed refrigerant is made to flow down from the refrigerant inlet portion 5 provided in the head portion 4 into the tank body portion 2, and the liquid refrigerant stored in the bottom portion of the tank body portion 2 is passed through the refrigerant outlet pipe 7 to the head. It is configured to flow out from the refrigerant outlet portion 6 of the portion 4.

The tank main body 2 is formed of a material such as aluminum which is lightweight and relatively easy to mold, and presses the concave and convex portion 22 formed on the outer periphery of the head portion 4 by crimping means such as caulking. As a result, the head portion 4 is connected. The tank body 2 has an upper portion formed in a large diameter portion 2a and a lower portion formed in a small diameter portion 2b having a smaller diameter than the large diameter portion 2a. The small-diameter portion 2b is formed by tapering the lower half of the small-diameter portion 2b to reduce the volume around the refrigerant outlet pipe 7. By doing this, the amount of refrigerant used is suppressed, and even if the amount of refrigerant decreases due to the tapered shape of the small diameter portion 2b, the height of the stable liquid level in the tank main body 2 increases, and the bottom 2c It is possible to reliably suck up the liquid refrigerant from the refrigerant take-out pipe 7 that is hung down.

The head portion 4 attached to the large-diameter portion 2 a has a refrigerant inlet portion 5 whose one end is connected to an inlet conduit 16 which communicates with a condenser and whose other end communicates with the internal space of the tank body 2. Are formed. Adjacent to the refrigerant inlet portion 5, a refrigerant outlet portion 6 having an L-shaped cross section is formed, one end of which is connected to an outlet conduit 17 communicating with the expansion valve, and the other end of which is connected to the refrigerant outlet pipe 7. There is.

Incidentally, “8” is a sight glass for visually observing the state of the refrigerant flowing through the refrigerant outlet portion 6, “27” is a pressure switch for detecting the pressure of the refrigerant in the liquid tank 20, and “29”. Is an O-ring for enhancing the airtightness between the tank body 2 and the head 4.

As shown in an enlarged view in FIG. 2, the desiccant filling section 30 is fixed to the refrigerant take-out pipe 7 hanging from the head section 4 in the middle section of the tank main body section 2. By the desiccant filling section 30, a refrigerant inflow chamber 41 into which the refrigerant from the refrigerant inlet section 5 flows and a refrigerant storage chamber 42 in which the liquid refrigerant is stored are formed in the tank main body 2 so as to be partitioned. There is. The desiccant filling section 30 has, as its storage container, an upper support plate 31 fixed to the refrigerant discharge pipe 7 by pressure bonding, and a lower support plate 32 attached to the lower side thereof by caulking or the like. There is. A large number of small holes 33 are formed on the upper surface of the upper support plate 31 to guide the refrigerant into the desiccant filling section 30, and the bottom surface of the lower support plate 32 is filled with the refrigerant from the desiccant filling section 30. A large number of small holes 34 for guiding the inside of the main body 2 are formed.

As shown in FIG. 2, a net-like mesh strainer 37 is arranged above the desiccant filling section 30, and a desiccant 38 is enclosed below the mesh strainer 37. A cushion 39 is arranged below this. The mesh strainer 37 has a function of removing relatively fine dust and foreign matter in the refrigerant passing through the mesh strainer 37. For example, a net of 100 mesh is used. The desiccant 38 functions to adsorb moisture in the refrigerant, and silica gel, synthetic zeolite or the like is used, for example. The cushion 39 functions as a cushioning material for preventing the desiccant 38 from being crushed by vibration when mounted on a vehicle, and glass wool or the like is used, for example.

Particularly, in the liquid tank 20 of the present embodiment, a pressure equalizing pipe 43 that connects the refrigerant inflow chamber 41 and the refrigerant storage chamber 42 is provided to penetrate the desiccant filling section 30. The pressure equalizing pipe 43 is composed of, for example, a hollow pipe made of aluminum or the like, and is fixed to the upper and lower support plates 31 and 32. The pressure equalizing tube 43 extends upward in the refrigerant inflow chamber 41, and the refrigerant inflow port 44 of the pressure equalizing tube 43 facing the refrigerant inflow chamber 41 is formed above the desiccant filling section 30. The height from the upper surface of the upper support plate 31 to the refrigerant inlet 44 varies depending on the capacity of the liquid tank 20, but is set to about 20 mm, for example. Further, in the illustrated example, the inner diameter of the pressure equalizing tube 43 is almost the same as the inner diameter of the refrigerant outlet tube 7, but it has been confirmed by an experiment that the effect described later is sufficiently exerted even if the inner diameter is about 1 mm to 2 mm. There is. Furthermore, in order to prevent the liquid refrigerant from the refrigerant inlet portion 5 from directly flowing into the pressure equalizing tube 43, the refrigerant inlet port 44 of the pressure equalizing tube 43 is not provided directly below the refrigerant inlet portion 5 as shown in the figure. It is preferable to provide it at a position as far as possible from the refrigerant inlet portion 5.

Next, the operation of this embodiment will be described.

When the operation of the cooling cycle is stopped and the pressure in this cycle reaches the equilibrium state, as shown in FIG. Thus, not only the refrigerant storage chamber 42 of the liquid tank 20 but also the refrigerant inflow chamber 41 is accumulated. Further, a part of the lubricating oil L used in the compressor or the like is also stored in the liquid tank 20 in a state of being dissolved in the liquid refrigerant R.

When the compressor of the cooling cycle is started from this state, the liquid refrigerant stored in the bottom portion 2c is taken out by the refrigerant take-out pipe 7 and guided from the refrigerant outlet part 6 to the expansion valve via the outlet conduit 17. At this time, the lubricating oil L accumulated in the refrigerant inflow chamber 41 is taken into the pressure equalizing pipe 43 from the refrigerant inlet 44 together with the liquid refrigerant R, passes through the pressure equalizing pipe 43 and bypasses the desiccant filling section 30. It flows down into the refrigerant storage chamber 42. Therefore, as compared with the case where the lubricating oil L passes through the desiccant filling section 30 and is taken into the refrigerant take-out pipe 7, the lubricating oil L is taken out more quickly in the refrigerant take-out pipe 7. Therefore, since the lubricating oil L accumulated in the liquid tank 20 can be quickly returned to the compressor, that is, "oil return" can be performed quickly, the driving time of the compressor is shortened when the lubricating oil is less than the steady state, and the piston The smooth operation of the sliding members such as the above is not hindered, and the malfunction of the compressor can be prevented in advance.

At the start of the cooling cycle, some of the lubricating oil L and the refrigerant R flow by-passing the desiccant filling section 30, so that the foreign substances contained in these cannot be removed. The collection rate of foreign matter in 30 is not 100%, and foreign matter contained in the refrigerant is removed while the refrigerant is circulating multiple times in the cooling cycle. Will not occur.

When the operation of the cooling cycle reaches a steady state, the gas-liquid mixed refrigerant condensed in the condenser enters the tank main body 2 through the inlet conduit 16 and the refrigerant inlet 5 of the head 4. Inflow. This refrigerant flows down in the desiccant filling section 30, the dust and foreign matters in the refrigerant are removed by the mesh strainer 37, and the moisture in the refrigerant is adsorbed by the desiccant 38. The liquid refrigerant from which water and foreign substances have been removed and which is stored in the bottom portion 2c is taken out by the refrigerant take-out pipe 7 and guided from the refrigerant outlet part 6 to the expansion valve via the outlet conduit 17.

When the operation of the cooling cycle is continued, powder such as aluminum which is a forming material of the tank main body 2 and products caused by corrosion, and abrasion powder of equipment such as a compressor which constitutes the cooling cycle are dried. A large amount of the deposited S in the agent filling portion 30 may cause clogging of the small holes 33 and 34 of the upper and lower support plates 31 and 32, the desiccant 38, and the cushion 39. Therefore, the flow resistance of the refrigerant in the desiccant filling section 30 increases, the liquid refrigerant accumulates in the refrigerant inflow chamber 41, and the pressure loss in the desiccant filling section 30 increases. When the pressure loss in the desiccant filling section 30 increases and it becomes difficult for the liquid refrigerant to accumulate in the refrigerant storage chamber 42, since the liquid refrigerant is constantly taken out by the refrigerant take-out pipe 7, the refrigerant in the refrigerant storage chamber 42 is decompressed. There is a risk of boiling. When such refrigerant depressurization boiling occurs, the evaporation pressure of the refrigerant in the evaporator rises, which causes a problem that the cooling capacity remarkably decreases.

However, in the liquid tank 20 of this embodiment, since the refrigerant inflow chamber 41 and the refrigerant storage chamber 42 are communicated with each other by the pressure equalizing pipe 43, both chambers 41, 42 are pressure-equalized. Since the depressurized boiling of the refrigerant in the refrigerant storage chamber 42 can be suppressed, the evaporation pressure of the refrigerant in the evaporator does not rise and the cooling capacity can be reliably prevented from lowering.

Even when a large amount of liquid refrigerant is accumulated in the refrigerant inflow chamber 41 due to the progress of clogging, this liquid refrigerant flows into the pressure equalizing pipe 43 from the refrigerant inflow port 44, and passes through the pressure equalizing pipe 43 to store in the storage chamber 42. Will be stored in the bottom of the liquid body 2. Therefore, even if the desiccant filling portion 30 is completely clogged, the flow of the cooling medium can be secured to some extent via the pressure equalizing pipe 43. Therefore, the pressure equalizing pipe 43 exerts a function of quickly returning the oil at the time of starting the cooling cycle and a function of suppressing the depressurized boiling of the refrigerant during the operation and also a function of preventing the liquid tank 20 from being clogged. It will be.

Further, since the refrigerant inlet 44 of the pressure equalizing pipe 43 is formed above the desiccant filling section 30, the refrigerant inlet chamber 41 is provided when the desiccant filling section 30 is not clogged. The liquid refrigerant inside flows out to the refrigerant storage chamber 42 through the pressure equalizing pipe 43 very rarely.

FIG. 3 is a longitudinal sectional view showing another embodiment of the present invention. Although the desiccant filling section 30 in the above-described embodiment is provided in the substantially central portion of the tank main body section 2, the desiccant filling section 51 of the liquid tank 50 is attached to the end portion of the refrigerant discharge pipe 7. A holding plate 52 is provided, and the holding plate 52 is used to press and fix the strainer 37, the cushion 39, and the desiccant 38 to the bottom of the tank body 2. Further, in the liquid tank 50, the desiccant filling section 51 serves as the refrigerant storage chamber 42. Even in this type of liquid tank 50, by providing the pressure equalizing pipe 43 in the desiccant filling section 51, the same operation and effect as described above can be obtained.

Although the pressure equalizing pipe 43 is a straight pipe in the illustrated embodiment, the portion facing the refrigerant inflow chamber 41 is formed in an “inverted U” shape, and the refrigerant inlet 44 is formed downward. You can do it. This makes it difficult for dust floating in the gas refrigerant to be taken into the pressure equalizing pipe 43. Also, the pressure equalizing pipe 43 may be filled with a mesh strainer, a desiccant, or the like. In this case, the liquid refrigerant does not pass through the pressure equalizing pipe 43 during the normal operation even if a desiccant 38 or the like having the same roughness as the desiccant 38 filled between the upper and lower support plates 31 and 32 is used. The desiccant 38 or the like in the pressure equalizing pipe 43 is not clogged, and the liquid refrigerant overflowing from the refrigerant inflow chamber 41 flows down to the refrigerant storage chamber 42 without resistance.

[0033]

[Effect of the device]

 As described above, according to the present invention, a pressure equalizing pipe that connects the refrigerant inflow chamber and the refrigerant storage chamber is provided in the desiccant filling section, and the refrigerant inlet port of the pressure equalizing tube facing the refrigerant inflow chamber is placed in the desiccant filling section. Since it is a liquid tank that is formed at a predetermined higher position, when the cooling cycle is started, the lubricating oil that has accumulated and dissolved in the liquid refrigerant in the refrigerant inflow chamber is taken into the pressure equalizing pipe from the cooling medium inlet. Since it flows by bypassing the desiccant filling part, it is quickly taken out by the cooling medium take-out pipe. Therefore, when the cooling cycle is stopped, the lubricating oil accumulated in the liquid tank is quickly returned to the compressor, which can prevent the malfunction of the compressor from occurring. Even when the desiccant filling section becomes clogged and the pressure loss in the desiccant filling section increases, the refrigerant inflow chamber and the refrigerant storage chamber communicate with each other by the pressure equalizing pipe, so that the pressure is equalized. The reduced pressure boiling of the refrigerant in the chamber can be suppressed, the evaporation pressure of the refrigerant in the evaporator does not rise, and the cooling capacity can be reliably prevented from decreasing. Further, even when the desiccant filling section is completely clogged, the flow of the refrigerant can be ensured to some extent through the pressure equalizing pipe, so that the liquid tank can be prevented from being clogged.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view showing a main part of the embodiment.

FIG. 3 is a vertical sectional view showing another embodiment of the present invention.

FIG. 4 is a vertical sectional view showing a conventional liquid tank.

[Explanation of symbols]

2 ... Tank main body 3 ... Upper opening 4
… Head part 5… Refrigerant inlet part 6… Refrigerant outlet part 7
... Refrigerant take-out pipe 30 ... Desiccant filling part 31 ... Upper support plate 3
2 ... Lower support plate 33 ... Small hole (on upper support plate) 34 ... Small hole (on lower support plate) 41 ... Refrigerant inflow chamber 42 ... Refrigerant storage chamber 4
3 ... Pressure equalizing tube 44 ... Refrigerant inlet S ... Deposit

Claims (1)

[Scope of utility model registration request] 1. A tank body (2) and this tank body
The head part (4) that closes the upper opening (3) of (2) and the desiccant filling part (30) that allows the refrigerant flowing from the refrigerant inlet part (5) of the head part (4) to pass through the inside. ), And is connected to the desiccant filling section (30) so that the liquid refrigerant stored in the lower portion of the tank body section (2) flows out through the refrigerant outlet (6) of the head section (4). A refrigerant outlet pipe (7), and a refrigerant inlet chamber (41) into which the refrigerant from the refrigerant inlet portion (5) flows,
In a liquid tank in which a refrigerant storage chamber (42) for storing a liquid refrigerant is partitioned and formed in the tank body (2) by the desiccant filling section (30), the refrigerant inflow chamber (41) and the A pressure equalizing pipe (43) communicating with the refrigerant reservoir chamber (42) is provided in the desiccant filling section (30), and a refrigerant inlet port of the pressure equalizing pipe (43) facing the refrigerant inflow chamber (41).
A liquid tank characterized in that the (44) is formed at a predetermined height above the desiccant filling section (30).