JP2891269B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus in which a refrigerant condenser has a supercooling zone.

[0002]

2. Description of the Related Art In general, in a refrigeration cycle of an air conditioner for a vehicle or the like, when charging a refrigerant, a refrigerant charging amount is checked while observing a state of the refrigerant flowing from a sight glass provided on an upper portion of a receiver. Is being done. Normally,
A method is adopted in which the presence or absence of air bubbles contained in the flow is determined, and a certain amount of air is sealed after the air bubbles disappear.

[0003]

However, since the determination of the end of the refrigerant charging is determined based on the experience of the worker,
In some cases, the amount of charged refrigerant varies depending on the operator. Especially for vehicles, it is difficult to manage properly in the market,
Generally, it is easy to overfill. As a result, for example, in a refrigeration system having a supercooling region in a refrigerant condenser, the power of the refrigerant compressor needs to be increased due to a high pressure rise (see FIG. 6) due to the overfilling of the refrigerant, and the amount of heat radiation is reduced. Therefore, there were problems such as a decrease in cooling capacity.

[0004] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a refrigerating apparatus which prevents overfilling of a refrigerant and has excellent cycle efficiency.

[0005]

In order to achieve the above object, the present invention comprises a refrigerant condenser for condensing and liquefying a supplied high-temperature, high-pressure gas-phase refrigerant, and supercooling the outlet side of the refrigerant condenser. In the refrigeration apparatus having a region, a portion of the refrigerant condenser where supercooling is started and a refrigerant passage downstream of the refrigerant condenser communicate with each other to remove a part of the refrigerant flowing through the refrigerant condenser. Technical means that a bypass passage for bypassing the cooling area and leading to the downstream of the refrigerant condenser is provided, and a connecting portion between the bypass passage and the refrigerant passage is provided with a sight glass for observing the state of the refrigerant. I do.

[0006]

According to the refrigeration system of the present invention having the above-described structure, the state of the refrigerant flowing out of the refrigerant condenser and flowing through the refrigerant passage, and the state of the refrigerant flowing into the refrigerant passage through the bypass passage from the middle of the refrigerant condenser. Can be observed from a sight glass provided downstream of the refrigerant condenser.

When the amount of the charged refrigerant is small, a gas-liquid two-phase refrigerant flows out of the refrigerant condenser.
It can be observed that the whole is white and cloudy, and it can be determined that the refrigerant is insufficient. Thereafter, when the refrigerant is gradually filled, the liquid refrigerant starts to be filled with the liquid refrigerant from the outlet side of the refrigerant condenser and has supercooling. At this time, since the refrigerant flowing in the bypass passage is a gas-liquid mixed two-phase refrigerant, bubbles flowing out of the bypass passage are observed in the flow of the liquid refrigerant in the sight glass.

When the refrigerant is further charged and filled with the liquid refrigerant up to the start position of the supercooling, the liquid refrigerant flows out of the bypass passage as well. You can observe the condition. At this point, it can be determined that the amount of the filled refrigerant is appropriate.

[0009]

Next, a refrigeration apparatus according to the present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is an overall configuration diagram of the refrigeration apparatus.

The refrigeration system 1 of the present embodiment includes a refrigerant compressor 2,
Each component of the refrigerant condenser 3, the expansion valve 4, and the refrigerant evaporator 5 is provided, and is connected in a ring shape by a refrigerant pipe 6 to form a refrigeration cycle.

The outlet side refrigerant pipe 6a of the refrigerant condenser 3
In the (refrigerant passage of the present invention), a sight glass 7 for observing the state of the refrigerant is provided. Sight glass 7
Is composed of a body 7a interposed in the refrigerant pipe 6a and a welding glass 7c fitted into a viewing window 7b formed in the body 7a.
Is provided.

The refrigerant condenser 3 is constituted by alternately laminating flat tubes 8 forming a refrigerant passage and corrugated fins 9 for heat radiation, and the left and right ends of each flat tube 8 communicate with each flat tube 8. Tanks 10 and 11 are arranged. Each of the tanks 10 and 11 has a cylindrical tank tube 10a and 11a, respectively.
Caps 10b and 11 to be placed on both upper and lower ends of 11a
b.

The inside of the tank 10 is divided into two upper and lower sections by a partition plate 12, and an inlet pipe 13 serving as an inlet for the refrigerant is provided on the upper side, and an outlet for the coolant is provided on the lower side. An outlet pipe 14 is provided.

The other tank 11 has a tank tube 11
The inside of the tank tube 11a is defined by a long plate 15 having the same length as that of FIG.
), Two vertically extending refrigerant passages 16, 1
7 is formed inside the tank 11. These two refrigerant passages 16 and 17 are arranged in the passage direction of the flat tube 8 (FIG. 1).
Are formed on the flat tube 8 side and on the outside, and are communicated at both ends of the tank tube 11a via a gap between the cap 11b and the long plate 15. As shown in FIG. 2, the cross-sectional area of the refrigerant channels 16 and 17 is larger in the refrigerant channel 17 than in the refrigerant channel 16.

In the refrigerant condenser 3, the entire lower side of the partition plate 12 of one of the tanks 10 is set as a subcooling region, and the subcooling region is bypassed to form a refrigerant passage 17 in front of the subcooling region. And sight glass 7 provided in refrigerant pipe 6a
And the capillary tube 18 (bypass passage of the present invention)
Connected by In addition, the capillary tube 1
8 is connected to the bottom of the body 7a of the sight glass 7,
The connection position is set on the downstream side (left side in FIG. 1) of the partition 7d of the viewing window 7b.

Next, the operation of this embodiment accompanying the charging of the refrigerant into the cycle will be described with reference to FIGS. When the amount of the refrigerant sealed in the cycle is small, the gas-liquid two-phase refrigerant mixed with the gas refrigerant flows out from the outlet of the refrigerant condenser 3. Therefore, in the sight glass 7, as shown in FIG.
The flow of the white turbid refrigerant containing bubbles can be observed. In this state, it can be determined that the refrigerant is insufficient.

As the refrigerant is gradually filled, the refrigerant is gradually filled with the liquid refrigerant from the outlet side of the refrigerant condenser 3 to have supercooling. Here, when the refrigerant makes a U-turn from the upper side to the lower side of the refrigerant condenser 3, most of the gas-liquid two-phase refrigerant flows to the lower side through the refrigerant flow path 16 and some of the refrigerant flows. Flows into the coolant channel 17 through a gap between the long plate 15 and the cap 11b.

Thereafter, the subcooling area is filled with the liquid refrigerant,
When the liquid refrigerant reaches the upper end of the refrigerant flow path 16, as shown in FIG. 4, the liquid refrigerant that has overflowed into the refrigerant flow path 17 through the gap between the long plate 15 and the cap 11 b enters the refrigerant flow path 17. Start to accumulate. At this time, the refrigerant guided downstream of the refrigerant condenser 3 via the capillary tube 18 is a gas-liquid mixed two-phase refrigerant. Therefore, in the sight glass 7, air bubbles can be observed in the downstream half of the sight glass 7 in the flow of the liquid refrigerant flowing out of the refrigerant condenser 3 (see FIG. 4). Since the amount of the refrigerant flowing out through the capillary tube 18 is very small, the degree of supercooling of the refrigerant condenser 3 hardly changes.

When the liquid refrigerant that has been filled with the refrigerant and starts to accumulate in the refrigerant flow path 17 reaches the opening of the capillary tube 18, all the refrigerant guided to the sight glass 7 through the capillary tube 18 is mixed with the liquid refrigerant. Become. Therefore, in the sight glass 7, as shown in FIG. 5, it is possible to observe a transparent state in which air bubbles are not included in the flow.

If the refrigerant is charged any more, it will be overfilled, and the high pressure will rise sharply as shown in FIG. In addition,
FIG. 6 shows the relationship between the amount of refrigerant charged in the cycle and the high pressure. In FIG. 6, the range of (1) is insufficient refrigerant, the range of (2) is an appropriate amount, and the range of (3) is overfilled. Becomes

[0021]

According to the present embodiment, the filling of the refrigerant is stopped when the air bubbles observed in the downstream half of the sight glass 7 have disappeared, so that an appropriate amount of the refrigerant can be sealed. Therefore, it is possible to easily prevent overfilling of the refrigerant by visual observation with the sight glass 7 without relying on the experience of the worker who performs the filling operation as in the related art. As a result, an excellent cycle can always be obtained efficiently.

In the present embodiment, the refrigerant flow path 17 is formed in the other tank 11, but may be formed by another component such as a receiver or a pipe instead of the refrigerant flow path 17. Although the capillary tube 18 is connected to the bottom of the body 7a of the sight glass 7, it may be attached in the lateral direction of the body 7a. Further, an orifice may be used instead of the capillary tube 18.

The state of the refrigerant flowing out of the refrigerant condenser 3 and the state of the refrigerant flowing out of the capillary tube 18 are observed with one sight glass 7, but are separately observed with the two sight glasses. Is also good.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a refrigeration apparatus.

FIG. 2 is a sectional view of a tank tube.

FIG. 3 is an operation explanatory view of the present embodiment.

FIG. 4 is an operation explanatory diagram of the present embodiment.

FIG. 5 is an operation explanatory view of the present embodiment.

FIG. 6 is a graph showing a relationship between a refrigerant charging amount and a high pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus 3 Refrigerant condenser 6a Refrigerant piping (refrigerant passage) 7 Sight glass 18 Capillary tube (bypass passage)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 54-79563 (JP, U) JP-A 54-92466 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25B 39/04 F25B 45/00 F25B 49/02 530

Claims (1)

(57) [Claims] 1. A refrigerating apparatus comprising a refrigerant condenser for condensing and liquefying a supplied high-temperature, high-pressure gas-phase refrigerant, and having a subcooling region at an outlet side of the refrigerant condenser. A bypass that communicates a part where cooling is started with a refrigerant passage downstream of the refrigerant condenser and guides a part of the refrigerant flowing through the refrigerant condenser to the downstream of the refrigerant condenser by bypassing the supercooling region; A refrigerating apparatus comprising: a passage; and a sight glass for observing a state of the refrigerant provided at a connection between the bypass passage and the refrigerant passage.