JPH04283368A - Freezer - Google Patents

Abstract

PURPOSE:To provide a freezer device for preventing an overcharging of refrigerant and showing a superior cycle efficiency. CONSTITUTION:A refrigerant condensor 3 is constructed such that an entire lower stage of one tank 10 lower than a partition plate 12 is set as an overcooling region, and a refrigerant flow passage 17 within the other tank 11 before the overcooling region and a sight glass 7 disposed at a refrigerant pipe 6a at an outlet side of the refrigerant condensor 3 are connected by a capillary tube 18. Through the sight glass 7, the state of refrigerant flowing out of the refrigerant condensor 3 and the state of refrigerant bypassed through the overcooling region and guided to the downstream side of the refrigerant condensor 3 are observed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system in which a refrigerant condenser has a supercooling region.

0002

[Prior Art] Generally, when refrigerant is charged in a refrigeration cycle for a vehicle air conditioner, etc., the amount of refrigerant charged is checked while observing the state of the refrigerant flowing through a sight glass installed at the top of the receiver. It is being done. Normally,
The method used is to judge the presence or absence of air bubbles in the flow, and to fill in a certain amount after the air bubbles have disappeared.

0003

[Problem to be Solved by the Invention] However, since the decision to end refrigerant charging is based on the experience of the operator,
The amount of refrigerant charged may differ depending on the operator. In particular, in the case of vehicles, it is difficult to properly manage them in the market, and they are generally prone to overfilling. As a result, for example, in a refrigeration system in which the refrigerant condenser has a subcooling region, the high pressure rise due to overfilling of refrigerant (see Figure 6) requires an increase in the power of the refrigerant compressor, and the amount of heat dissipated decreases. This caused problems such as a decrease in cooling capacity.

The present invention was developed based on the above circumstances, and its object is to provide a refrigeration system with excellent cycle efficiency by preventing overfilling of refrigerant.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a refrigerant condenser that condenses and liquefies a supplied high-temperature, high-pressure gas phase refrigerant. In the refrigeration system, a part of the refrigerant condenser where subcooling starts is communicated with a refrigerant passage downstream of the refrigerant condenser, and a part of the refrigerant flowing through the refrigerant condenser is transferred to the supercooling section. The technical means includes providing a bypass passage that bypasses the cooling zone and guiding the refrigerant to the downstream side of the refrigerant condenser, and a sight glass for observing the state of the refrigerant at the connection between the bypass passage and the refrigerant passage. do.

[0006]

[Operation] The refrigeration system of the present invention having the above configuration can control the state of the refrigerant flowing out from the refrigerant condenser and flowing through the refrigerant passage, and the state of the refrigerant flowing into the refrigerant passage from the middle of the refrigerant condenser through the bypass passage. , can be observed through a sight glass installed downstream of the refrigerant condenser.

[0007] When the amount of refrigerant charged is small, gas-liquid two-phase refrigerant flows out from the refrigerant condenser, so the sight glass
It can be observed that the whole area is cloudy and it can be determined that there is a lack of refrigerant. After that, when the refrigerant is gradually filled, the refrigerant begins to be filled with liquid refrigerant from the outlet side of the refrigerant condenser, resulting in supercooling. At this time, since the refrigerant flowing through the bypass passage is a two-phase gas-liquid refrigerant, bubbles flowing out from the bypass passage are observed in the flow of the liquid refrigerant using the sight glass.

[0008] When the refrigerant is further filled and the liquid refrigerant is filled up to the point where supercooling starts, the liquid refrigerant also flows out from the bypass passage. The condition can be observed. At this point, it can be determined that the amount of refrigerant enclosed is appropriate.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a refrigeration system of the present invention will be explained based on an embodiment shown in the drawings. FIG. 1 is an overall configuration diagram of the refrigeration system.

The refrigeration system 1 of this embodiment includes a refrigerant compressor 2,
It is equipped with functional parts such as a refrigerant condenser 3, an expansion valve 4, and a refrigerant evaporator 5, which are connected in an annular manner through refrigerant piping 6 to form a refrigeration cycle.

[0011] Also, the outlet side refrigerant pipe 6a of the refrigerant condenser 3
(Refrigerant passage of the present invention) is provided with a sight glass 7 for observing the state of the refrigerant. The sight glass 7 consists of a body 7a interposed in a refrigerant pipe 6a, and a welded glass 7c fitted into a viewing window 7b formed in the body 7a, and a partition 7d is provided in the center of the viewing window 7b. ing.

The refrigerant condenser 3 is constructed by alternately stacking flat tubes 8 forming refrigerant passages and corrugated fins 9 for heat radiation, and the left and right ends of each flat tube 8 are connected to each other. Tanks 10 and 11 are arranged. Each tank 10, 11 includes a cylindrical tank tube 10a, 11a, and a tank tube 10a,
Caps 10b and 11 are placed over both upper and lower ends of 11a.
It consists of b.

One of the tanks 10 is partitioned into two upper and lower stages by a partition plate 12, with an inlet pipe 13 serving as an inlet for the refrigerant on the upper stage and an outlet for the refrigerant on the lower stage. An outlet pipe 14 is provided.

The other tank 11 is a tank tube 11
The inside of the tank tube 11a is partitioned by a long plate 15 having the same length as a (Fig. 2, tank tube 11a
), two refrigerant channels 16 and 1 extending vertically.
7 is formed inside the tank 11. These two refrigerant channels 16 and 17 are arranged in the passage direction of the flat tube 8 (see FIG.
The cap 1 is formed on the flat tube 8 side and the outside in the left-right direction of the tank tube 11a.
1b and the elongated plate 15 through a gap therebetween. Note that, as shown in FIG. 2, the cross-sectional area of the refrigerant flow paths 16 and 17 is larger in the refrigerant flow path 17 than in the refrigerant flow path 16.

In this refrigerant condenser 3, the entire area below the partition plate 12 of one tank 10 is set as a supercooling region, and the supercooling region is bypassed and the refrigerant flow path 17 in front of the supercooling region is set. and a sight glass 7 provided on the refrigerant pipe 6a.
Capillary tube 18 (bypass passage of the present invention)
connected by. In addition, capillary tube 1
8 is connected to the bottom of the body 7a of the sight glass 7,
The connection position is on the downstream side (
(left side of Figure 1).

Next, the operation of this embodiment associated with charging of refrigerant into the cycle will be explained based on FIGS. 3 to 5. When the amount of refrigerant sealed in the cycle is small, a gas-liquid two-phase refrigerant mixed with gas refrigerant flows out from the outlet of the refrigerant condenser 3. Therefore, in the sight glass 7, as shown in FIG. 3, it is possible to observe the flow of the refrigerant which is cloudy and contains bubbles. In this state, it can be determined that there is a refrigerant shortage.

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

[0018] After that, the supercooled region is filled with liquid refrigerant,
When the liquid refrigerant reaches the upper end of the refrigerant flow path 16, as shown in FIG. It starts to accumulate. At this time, the refrigerant guided downstream of the refrigerant condenser 3 via the capillary tube 18 is a two-phase gas-liquid mixed refrigerant. Therefore, in the sight glass 7, bubbles can be observed in the downstream half of the sight glass 7 in the flow of liquid refrigerant flowing out from the refrigerant condenser 3 (see FIG. 4).
. Note that since only a small amount of refrigerant flows out through the capillary tube 18, there is almost no change in the degree of subcooling of the refrigerant condenser 3.

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

[0020] If the refrigerant is charged more than this, overfilling will occur, and the high pressure will rise rapidly as shown in FIG. In addition, Figure 6 shows the relationship between the amount of refrigerant filled into the cycle and high pressure. In the figure, range (1) indicates insufficient refrigerant, range (2) indicates appropriate amount, and range (3) indicates that there is insufficient refrigerant. This will result in overfilling.

[0021]

Effects of the Invention In this embodiment, by stopping the refrigerant filling when the bubbles observed in the downstream half of the sight glass 7 disappear, an appropriate amount of refrigerant can be filled. Therefore, anyone can easily prevent overfilling of the refrigerant by visual inspection through the sight glass 7, without relying on the experience of the operator who performs the filling work as in the past. As a result, efficient cycles can always be obtained.

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

Although the state of the refrigerant flowing out from the refrigerant condenser 3 and the state of the refrigerant flowing out from the capillary tube 18 were observed using one sight glass 7, the state of the refrigerant flowing out from the capillary tube 18 was observed separately using two sight glasses. Also good.

[Brief explanation of the drawing]

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

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

FIG. 3 is an explanatory diagram of the operation of this embodiment.

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

FIG. 5 is an explanatory diagram of the operation of this embodiment.

FIG. 6 is a graph showing the relationship between the amount of refrigerant enclosed and high pressure.

[Explanation of symbols]

1 Refrigeration equipment 3 Refrigerant condenser 6a Refrigerant piping (refrigerant passage) 7 Sight glass

Claims (1)

[Claims] 1. A refrigeration system comprising a refrigerant condenser that condenses and liquefies a supplied high-temperature, high-pressure gas phase refrigerant, and having a supercooling region on the outlet side of the refrigerant condenser, wherein the refrigerant condenser is 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, bypassing the supercooling area. A refrigeration system comprising a passage and a sight glass for observing the state of the refrigerant at a connection between the bypass passage and the refrigerant passage.