JPH06101940A - Sealing of refrigerant - Google Patents

Abstract

PURPOSE:To obtain a method for sealing refrigerant in an amount suitable to provide the optimum supercooling without removing all the refrigerant from a refrigerating cycle. CONSTITUTION:In a supercooling cycle devoid of a proper supercooling zone on the inlet side of an expansion valve 6, a valve 14 provided on the inlet side of the expansion valve 6 and a refrigerant filler 1 are connected by a charging hose 11 and the refrigerant is poured into the refrigerant filler 1 from the high pressure side while the valve 3 is kept open. The foam in the refrigerant filler is visible through a sight glass 8 and, when the supercooling reaches 0 deg.C, the valve 3 is closed. The refrigerant filler 1 is first filled with the refrigerant in an amount to attain a proper supercooling and then transferred into a refrigerating cycle from the low pressure side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant charging method,
In particular, the present invention relates to a refrigerant encapsulation method capable of enclosing the amount of refrigerant in a refrigeration cycle so as to obtain an appropriate degree of supercooling.

[0002]

2. Description of the Related Art In a conventional refrigeration cycle including a refrigerant compressor, a refrigerant condenser, an expansion valve and a refrigerant evaporator, there is a subcool cycle in which the refrigerant on the inlet side of the expansion valve has a supercooling degree. In this subcool cycle, as shown in the relationship diagram between the refrigerant charge amount and the cycle efficiency in FIG. 3, the optimum refrigerant charge amount for operating the cycle at the highest efficiency is provided.

By the way, in a refrigeration cycle used for an air conditioner for an automobile, a rubber hose is used to withstand vibration of an engine, but the refrigerant in the refrigeration cycle leaks from the rubber hose by about several grams per year. Therefore, in order to maintain the proper degree of supercooling and operate the refrigeration cycle at the highest efficiency, it is necessary to additionally replenish the refrigeration cycle with refrigerant.

Conventionally, as a method of sealing the refrigerant in the refrigeration cycle, as disclosed in Japanese Utility Model Laid-Open No. 57-33975, it is appropriate to discharge all the refrigerant in the cycle, perform vacuuming work, and then perform proper operation. There is a type in which a refrigeration cycle is filled with an appropriate amount of refrigerant for providing a proper degree of supercooling.

[0005]

However, according to the above-mentioned conventional method of enclosing the refrigerant in the refrigeration cycle, all the refrigerant in the refrigeration cycle is exhausted, and after the vacuuming operation in the cycle, the proper amount is removed. There is a problem that the workability is not good because the work of enclosing the refrigerant is required.

[0006] Therefore, an object of the present invention is to provide a refrigerant enclosing method capable of enclosing an appropriate amount of refrigerant having an optimum degree of supercooling without removing all refrigerant in the refrigeration cycle.

[0007]

In order to achieve the above object, the present invention provides a compressor for compressing a gaseous refrigerant, and a gaseous refrigerant compressed by the compressor to be a liquid refrigerant. A condenser, an expansion valve that expands the refrigerant that is liquefied in the condenser into a mist-like refrigerant, and an evaporator that heat-exchanges the atomized refrigerant with the air. Then, in the refrigerant encapsulation method in which the refrigerant on the inlet side of the expansion valve has a subcooling cycle having a supercooling degree, the refrigerant on the inlet side of the expansion valve in the subcool cycle has a gas-liquid two-phase state and a liquid phase state. When the refrigerant on the inlet side of the expansion valve is in a gas-liquid two-phase state, the refrigerant is enclosed in the subcool cycle until the refrigerant on the inlet side of the expansion valve changes to a liquid phase state. However, when the refrigerant on the inlet side of the expansion valve is in the liquid phase, The refrigerant in the subcool cycle is discharged until the refrigerant on the inlet side of the expansion valve changes to a gas-liquid two-phase state, and then a predetermined amount of refrigerant corresponding to a predetermined degree of supercooling is sealed in the subcool cycle. The method of enclosing the refrigerant is adopted.

[0008]

According to the refrigerant charging method of the present invention having the above-described structure, first, in the subcool cycle, it is detected whether the refrigerant on the inlet side of the expansion valve is in the gas-liquid two-phase state or the liquid phase state. When the refrigerant on the inlet side of the expansion valve is in the gas-liquid two-phase state, the refrigerant is enclosed in the cycle until the moment it switches to the liquid phase state, and when it is in the liquid phase state, the refrigerant in the cycle until the moment it switches to the gas-liquid two-phase state. In any case, the state of the refrigerant on the inlet side of the expansion valve is brought to the state of the supercooling degree of 0 ° C. The state of the refrigerant is 0
After a state of ° C, by enclosing a predetermined amount of refrigerant corresponding to a predetermined degree of supercooling in the cycle, an appropriate amount of refrigerant capable of providing an appropriate degree of supercooling is enclosed. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerant encapsulation method using a refrigerant encapsulator according to the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of the refrigerant enclosure 1. In the pressure vessel 1 that can withstand high pressure,
A peep window glass 13 is provided so that the presence and amount of the refrigerant in the inside can be known. Further, a valve 2 for enclosing the refrigerant in the refrigeration cycle is provided on the upper side surface of the container 1, and a valve 3 for recovering the refrigerant in the refrigeration cycle into the container 1 is provided on the lower surface. The valve 3 also serves as a discharge port when the oil remaining in the container 1 is finally discharged. Since the refrigeration cycle is different for each vehicle type and the amount of the enclosed refrigerant is different, the amount of the refrigerant from the disappearance of bubbles in the sight glass 8 of the refrigeration cycle to the proper supercooling degree is provided next to the sight glass 13. ,
The scale is shown for each vehicle type.

In the refrigeration cycle for car air conditioners, several grams are leaked annually from a rubber hose or the like. In a subcool cycle with a supercooling degree, as shown in FIG. 3, there is an optimum amount of filling that maximizes the cycle efficiency and an optimum degree of subcooling already exists.
If the refrigerant leaks even if the optimal amount is filled in the initial stage, the degree of supercooling becomes small and the cycle efficiency also decreases.

Therefore, if the degree of supercooling is periodically checked and if it is insufficient, the refrigerant is filled until it becomes optimum, so that the car air conditioner can always be operated with the highest cycle efficiency. Less than,
A method of filling the refrigerant will be described.

As shown in FIGS. 4, 5 and 6, the expansion valve 6
Letting W be an appropriate degree of supercooling on the inlet side of, the refrigerant is enclosed in the refrigeration cycle in the following three cases.
As shown in FIG. 4, during operation of the refrigeration cycle, no bubbles are generated in the sight glass 8 on the refrigeration cycle side,
When the degree of subcooling is not optimal and the amount of refrigerant is small A
Then, as shown in FIG. 5, bubbles are confirmed from the sight glass 8 and in the case of clearly gas shortage B, and as shown in FIG. 6, the refrigerant is initially filled, or the refrigerant is emptied for repair or the like. The refrigerant encapsulation method can be classified into three types, C in the case of the above.

Under any of the conditions, the engine speed is set to the idling state and the air volume of the evaporator is set to Hi so that the supercooling degree check and the refrigerant injection can be performed under the same condition. Also, keep the glass and door open.

In each case, the method of enclosing A to C will be invented. At the inlet side of the expansion valve 6, since the refrigerant is in a liquid phase state, when no bubbles are seen from the sight glass 8 during the operation of the refrigeration cycle, as shown in the Mollier diagram of FIG. The case A in which the degree of supercooling is smaller than that in the state having the degree of cooling W and the amount of refrigerant is small, that is, when there is a refrigerant state on the inlet side of the expansion valve 6 between the states 1 to 4, will be described.

A charging hose 11 connects the insect valve 14 of the high-pressure liquid pipe 9 and the recovery valve 3 of the refrigerant enclosure 1. The recovery valve 3 is opened in a state where the refrigeration cycle is operated under constant conditions of idling and air volume Hi, and the refrigerant in the refrigeration cycle is gradually recovered into the refrigerant enclosure. At this time, the valve 2 is closed. Since the inside of the refrigerant enclosure 1 is at atmospheric pressure, the refrigerant flows into the refrigerant recovery device 1 due to the pressure difference from the high pressure side of the refrigeration cycle. Accordingly, the amount of refrigerant in the refrigeration cycle gradually decreases, and the degree of supercooling also decreases. Therefore, in FIG. 4, the state of the refrigerant on the inlet side of the expansion valve 6 gradually changes from the state to the state. Get closer. The moment when bubbles are seen from the sight glass 8 is when the state of the refrigerant coincides with the state on the saturated liquid line and the degree of supercooling is 0 ° C. At this time valve 3
Is closed and the charging hose 11 is removed.

The amount of the refrigerant collected in the refrigerant enclosure 1 is compared with a preset optimum amount of the applicable vehicle type (for example, the vehicle body A). As shown in FIG. 7, when the amount of the refrigerant is less than the optimum amount, the amount of the insufficient refrigerant is ΔW, and a new amount of the refrigerant is replenished to the refrigerant enclosure 1 by ΔW.

Next, FIG. 8 shows a method of replenishing the refrigerant to the enclosure. A new or filled refrigerant can 12 containing a refrigerant is placed with its head facing downward, and the charging hose 11
Through valve 3 to replenish the liquid refrigerant with ΔW. At that time, if the valve 2 is opened to purge the gas refrigerant to reduce the pressure in the refrigerant enclosure 1, the liquid refrigerant can easily enter from the refrigerant can 12.

After the refrigerant has been filled to the amount W of the refrigerant capable of providing an appropriate degree of cooling inside the refrigerant enclosure 1, the valve 2 and the insect valve 10 for enclosing the refrigerant on the low pressure side of the refrigeration cycle side.
The valve 2 is opened by communicating with the charging hose 11. The refrigerant in the vapor phase is sealed from the valve 2 provided at the top of the refrigerant enclosure 1 from the insect valve 10 provided in the refrigeration cycle. As the gas refrigerant in the refrigerant enclosure 1 gradually decreases, the pressure in the refrigerant enclosure 1 decreases and the liquid refrigerant gradually becomes a gas state. In this gas state, the refrigerant in the refrigerant enclosure 1 is filled into the low pressure side inside the refrigeration cycle until the refrigerant is emptied (only W). With this, an appropriate amount of refrigerant can be enclosed so as to achieve the optimum degree of supercooling.

Next, as shown in FIG. 5, it is confirmed that bubbles are generated from the sight glass 8 of the refrigeration cycle, and the refrigerant is in the gas-liquid two-phase state. At this time, in the same way as the conventional gas charging method, the refrigerant can is charged into the refrigeration cycle with the gas refrigerant and becomes a state on the saturated liquid line, and the gas charging is temporarily stopped at the moment when the bubbles disappear from the sight glass 8. To do.

Next, in the same manner as in the above embodiment, the refrigerant is replenished in advance to the proper value W into the refrigerant enclosure 1 in accordance with the applied vehicle type. Then, all the refrigerant W in the refrigerant enclosure 1 is enclosed inside the refrigeration cycle. The method of charging the refrigerant at this time is the same as in the above embodiment.

As shown in FIG. 6, in the case of initial refrigerant charging C
In this case, also, at this time, as in the embodiment shown in FIG. 5, the refrigerant gas is charged in the conventional manner, and the gas injection is temporarily stopped at the moment when the bubbles disappear from the cycle side cytosus 8. Then, the refrigerant is replenished to the appropriate value W in advance in the refrigerant enclosure 1 as in the above embodiment,
All the refrigerant W in the refrigerant enclosure 1 is enclosed in the refrigeration cycle.

By enclosing the refrigerant in the refrigeration cycle as in the present invention, there is no need to perform the work of re-inserting an appropriate amount of the refrigerant after removing all the refrigerant as in the conventional case, and it is possible to perform proper subcooling in a short time. It can be quantity.

In the first embodiment described above, the refrigerant in the refrigeration cycle is sealed in the refrigerant enclosure 1 until the refrigerant on the inlet side of the expansion valve 6 changes from the liquid phase state to the gas-liquid two phase state. A step of putting a shortage of refrigerant in the refrigerant enclosure 1 and then enclosing this refrigerant in the refrigerant cycle is taken. However, it is not limited to this, and may be sealed in another container from the liquid phase state to the gas-liquid two-phase state. In addition to the refrigerant extracted from the refrigerant cycle, the refrigerant corresponding to the degree of supercooling may be filled with an appropriate amount of new refrigerant.

In the above embodiment, when the state of the refrigerant having a supercooling degree of 0 ° C. is detected as in the first embodiment shown in FIG. 4, when the liquid state is switched to the gas-liquid two-phase state, 5
Although the state is slightly different from the state in which the gas-liquid two-phase state is switched to the liquid phase state as in the second embodiment shown in FIG. 2, the degree of supercooling is 0 ° C. in both cases, and the refrigerant charge amount is However, there is no problem as it is an error.

[0025]

As described above, according to the refrigerant enclosing method of the present invention, the supercooling degree of 0 ° C is first set, and the proper supercooling degree is dealt with from the supercooling degree of 0 ° C. Take the step of enclosing a quantity of refrigerant in the refrigeration cycle. Therefore,
Compared with the conventional work of removing the previous refrigerant and then refilling it with an appropriate amount of refrigerant, the amount of refrigerant having an appropriate degree of supercooling can be obtained in a short time, and workability is improved.

[Brief description of drawings]

FIG. 1 is a front view showing a refrigerant enclosing device used in a refrigerant enclosing method of the present invention.

FIG. 2 is an overall configuration diagram when the refrigerant enclosure of the present invention is connected to a refrigeration cycle.

FIG. 3 is a diagram showing a relationship between a refrigerant charging amount in a refrigeration cycle and cycle efficiency.

FIG. 4 is a Mollier diagram showing the state when the refrigerant is charged.

FIG. 5 is a Mollier diagram showing the state when the refrigerant is charged.

FIG. 6 is a Mollier diagram showing a state when the refrigerant is charged.

FIG. 7 is a diagram showing an appropriate amount of refrigerant when refrigerant is charged.

FIG. 8 is a diagram showing a method of replenishing the refrigerant in the refrigerant enclosure.

[Explanation of symbols]

 1 Refrigerant Encapsulator 2, 3 Valve 4 Refrigerant Compressor 5 Refrigerant Condenser 6 Expansion Valve 7 Refrigerator Evaporator 8 Sight Glass 10 Low Pressure Side Bug Valve 14 High Pressure Side Bug Valve

Claims (1)

[Claims] 1. A compressor for compressing a gaseous refrigerant, a condenser for cooling the gaseous refrigerant compressed by the compressor to a liquid refrigerant, and an expansion of the liquid refrigerant in the condenser. A subcooler having an expansion valve for turning the atomized refrigerant into an atomized refrigerant and an evaporator for exchanging the atomized refrigerant with the expansion heat with air, and the refrigerant on the inlet side of the expansion valve has a supercooling degree. In a refrigerant enclosing method of enclosing a refrigerant in a cycle, the refrigerant on the expansion valve inlet side in the subcool cycle detects which of a gas-liquid two-phase state and a liquid phase state, the expansion valve inlet When the refrigerant on the side is in a gas-liquid two-phase state, the refrigerant is sealed in the subcool cycle until the refrigerant on the side of the expansion valve inlet changes to the liquid phase state, and when the refrigerant on the side of the expansion valve inlet is in the liquid phase state, Until the refrigerant on the inlet side of this expansion valve changes to a gas-liquid two-phase state A refrigerant enclosing method of discharging a refrigerant in the subcool cycle and then enclosing a predetermined amount of refrigerant corresponding to a predetermined degree of supercooling in the subcool cycle.