JPH06241588A - Oil separator for refrigerator - Google Patents

Abstract

PURPOSE:To provide an oil separator for a refrigerator of which the operability and reliability are improved. CONSTITUTION:An oil separator for a refrigerator has a refrigerating/air- conditioning refrigerant circuit, and comprises a subcooling control valve 31 having operations for sensing temperature and pressure of lubricant flowing out from the separator 12, holding a valve open state only when the combination of the temperature and the pressure correspond to values corresponding to those in a subcooling range of refrigerant used for the circuit and feeding out the lubricant to a suction side of a compressor 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating machine oil separator provided in a refrigerant circuit for a refrigerating machine such as a refrigerating machine, an air conditioner, and a car air conditioner.

[0002]

2. Description of the Related Art FIG. 5 shows a refrigerant circuit of a conventional oil separator for a refrigerator, and FIGS. 6 and 7 schematically show an oil return mechanism of the refrigerant circuit.

As shown in FIG. 5, in a refrigerant circuit of a car air conditioner having a conventional oil separator, 11 is a compressor, an oil separator 12 is connected to the compressor 11, a condenser 13, a receiver 14, and an expansion. A valve 15 and an evaporator 16 are connected to each other and circulatory connected to the compressor 11. An oil return circuit 17 is formed between the compressor 11 and the oil separator 12.

The refrigerant gas during operation of the compressor 11 is separated from the lubricating oil by the oil separator 12 as shown by the arrow in FIG. 5, and only the refrigerant gas is sent to the condenser 13 and condensed there. , Then the receiver 14
The uncondensed gas is separated with. Then, after being adiabatically expanded by the expansion valve 15, it is evaporated by the evaporator 16 and returned to the compressor 11. On the other hand, the lubricating oil separated by the oil separator 12 returns to the compressor 11 by the oil return circuit 17.

[0005]

In a refrigerant circuit for a car air conditioner having the above-mentioned conventional oil separator,
The refrigerant gas flowing into the oil separator 12 is in a high pressure state because it is the discharge gas from the compressor 11, while the oil return circuit 17 connected to the oil separator 12 is connected to the suction portion of the compressor 11 and therefore has a low pressure. It is in a state. It is necessary to reduce the pressure of the lubricating oil sent from the oil separator 12. Conventionally, for example, a capillary tube 18 is provided in the oil return circuit 17 as shown in FIG. 6, and a ball valve 19 is provided in the oil separator 12 as shown in FIG.

However, in the oil return circuit 17 shown in FIG. 6 in which the capillary tube 18 is provided, since the capillary tube 18 is a fixed throttle, the discharge and suction pressure differences due to the difference in the operating state of the compressor 11 are caused. However, there is a problem that the amount of oil returned is not stable. Therefore, the inflow of oil into the oil separator 12 is reduced, and under the condition that the differential pressure is large, the discharged refrigerant gas is discharged into the oil separator 1.
In some cases, the air would blow through from No. 2 to the compressor 11.

In the case where the ball valve 19 is provided in the oil separator 12 shown in FIG. 7, it is necessary to store oil at the bottom of the oil separator 12 in order to float the ball. In addition, there was a drop in the oil separation function, and more oil had to be injected into the system. In addition, the valve mechanism must be housed inside the oil separator 12, which causes a problem that the oil separator 12 becomes large. Furthermore, for example, when it is mounted on a car air conditioner, the blocking function of the ball valve 19 is hindered by vibration, and the durability deteriorates.

The present invention solves such problems, and an object of the present invention is to provide an oil separator for a refrigerating machine which is improved in operability and reliability.

[0009]

A refrigerating machine oil separator of the present invention that achieves the above-mentioned object is a refrigerating machine oil separator provided in a refrigerating and air-conditioning refrigerant circuit. Detects temperature and pressure, and keeps the fluid open to the suction side of the compressor only when the combination of temperature and pressure has a value corresponding to the supercooled region of the refrigerant used in the refrigerant circuit. It is characterized in that it has a valve mechanism for causing it to flow out.

[0010]

[Function] The supercooling control valve detects the temperature and pressure of the fluid discharged from the oil separator, and the combination of the temperature and the pressure distinguishes the fluid from the heating area or the supercooling area of the refrigerant. That is, only when the fluid is liquid, the valve mechanism is opened and the flow rate is proportionally controlled to flow down. In a normal operating state, oil is continuously discharged from the oil separator, and the supercooling fluid flowing into the supercooling control valve is oil.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a refrigerant circuit having an oil separator for a refrigerator according to an embodiment of the present invention, FIG. 2 shows a cross section of a supercooling control valve of an oil return circuit, and FIG. 3 shows a bottom view of the supercooling control valve. Indicates. It should be noted that the members having the same functions as those of the related art are designated by the same reference numerals, and the duplicate description will be omitted.

As shown in FIG. 1, in the refrigerant circuit of the present embodiment, 11 is a compressor, and an oil separator 12, a condenser 13, a receiver 14, an expansion valve 15 and an evaporator 16 are connected to the compressor 11 to form a compressor. It is circularly connected to 11. Further, an oil return circuit 17 is formed between the compressor 11 and the oil separator 12, and a supercooling control valve 31 is in contact with the suction pipe of the compressor 11 in the oil return circuit 17 so that heat can be transferred. It is provided.

In this supercooling control valve 31, as shown in FIGS. 2 and 3, a valve mechanism 33 is airtightly mounted on the upper part of the case 32 by screw engagement and is connected to the valve mechanism 33. The outlet joint 34 and the inlet joint 35 are mounted by engagement so as to be substantially orthogonal to each other. The outlet joint 34 is connected to the compressor 11, while the inlet joint 35 is connected to the oil separator 12.

In the valve mechanism 33, the valve case main body 37 screwed into the case 32 with the airtight seal 36 has a cylindrical shape with an open upper end, and the lower end portion has an outlet hole 38 communicating with the outlet joint 34 and the inlet joint 35. An inlet hole 39 is formed. A fixed valve 40 is provided in the upper portion of the valve case body 37.
Is screwed with a sealing O-ring 41, and a moving valve 42 is slidably fitted to the lower part of the fixed valve 40.
The movable valve 42 and the movable valve 42 are airtightly connected by a stretchable bellows 43. Further, a capillary tube 44 is attached to the upper portion of the fixed valve 40, and the space 45 formed by the capillary tube 44 and the bellows 43 has the same amount of refrigerant circuit as the amount of saturated gas over the entire temperature range used. Is filled with the refrigerant. Case 3
A contact portion 46 for holding the suction pipe of the compressor 11 as a contact guide is formed on the side portion 2 of the compressor 11, and heat can be transferred between the fluid of the valve mechanism 33 and the compressor 11.

The refrigerant gas from the compressor 11 is separated from the lubricating oil by the oil separator 12 as shown by the arrow in FIG.
3, the receiver 14, the expansion valve 15, and the evaporator 16 circulate and return to the compressor 11. On the other hand, the fluid (lubricating oil) separated by the oil separator 12 is used in the oil return circuit 17
It returns to the compressor 11 by (supercooling control valve 31).

At this time, in the supercooling control valve 31, as shown in FIGS. 2 and 3, the fluid discharged from the oil separator 12 is passed through the inlet joint 35 from the inlet hole 39 of the valve mechanism 33 to the valve case body 37. It flows into the interior and fills the space between the valve case body 37 and the bellows 43. Then, the temperature and pressure of the fluid are transmitted to the refrigerant in the space 45 constituted by the capillary tube 44, the bellows 43 and the like. The pressure of this fluid is almost equal to the pressure of the refrigerant discharged from the compressor 11, and the refrigerant is generally heated. Therefore, the pressure of the refrigerant in the space 45 inside the bellows 43 becomes a saturated vapor pressure corresponding to the fluid temperature.

On the other hand, the suction pipe of the compressor 11 is held in contact with the contact portion 46 of the case 37, the fluid is subjected to a cooling action, and when this fluid is a fluid such as oil, the temperature is raised by this cooling action. descend. Then, when the temperature reaches a temperature corresponding to a weak cooling region with respect to the discharge pressure saturation temperature, the bellows 43 itself due to a pressure difference between the inside and outside of the bellows 43 (pressure in the space 45 = saturated vapor pressure in a weak cooling state <discharge pressure). The moving valve 42 slides by overcoming the elastic force of the above, and the outlet hole 38 is opened. Therefore, this outlet hole 38
Since the discharge and suction pressure difference of the compressor 11 acts on the compressor 1, the lubricating oil flows through the outlet joint 34 to the compressor 1
1 is supplied.

When the fluid discharged from the oil separator 12 and flowing into the inside of the valve case body 37 from the inlet hole 39 of the valve mechanism 33 through the inlet joint 35 is the discharged refrigerant gas (heating gas), the bellows. The temperature of 43 is governed by the gas temperature, the pressure in the space 45> the discharge pressure, the outlet hole 38 is closed, and the fluid does not flow. Thus, the supercooling control valve 31 supplies only the lubricating oil to the compressor 11.

In the above embodiment, the temperature and pressure of the fluid discharged from the oil separator 12 is detected, and the combination of the temperature and pressure is used in the supercooling region of the refrigerant used in the refrigerant circuit. The oil return circuit 17 is provided with the subcooling control valve 31 having the valve mechanism 33 that opens only when the value is equivalent.
However, the present invention is not limited to this,
For example, the supercooling control valve 31 may be arranged in the suction part of the compressor 11.

FIG. 4 shows a cross section of the main part of the compressor in which the supercooling control valve is arranged in the suction part. As shown in FIG. 4, in this embodiment, the supercooling control valve 31 is arranged in the suction portion 51 of the compressor 11. In the figure, 52 is a crankcase and 53 is an oil return hole. The operation is the same as that described above except that the supercooling control valve 31 is cooled by the suction portion 51 of the compressor 11, and thus the description thereof is omitted.

[0022]

As described above in detail with reference to the embodiments, according to the oil separator for a refrigerator of the present invention, the temperature and pressure of the fluid flowing out from the bottom portion of the oil separation mechanism are detected to detect the temperature and the pressure. Since the valve mechanism of the action of causing the fluid to flow to the suction side of the compressor by keeping the valve open state is provided only when the combination of the pressures has a value corresponding to the supercooling region of the refrigerant used in the refrigerant circuit, With the supercooling control valve, only the lubricating oil is continuously returned to the compressor during normal operation from the oil separator to prevent the separated lubricating oil from staying in the oil separator, and the operability and reliability can be improved. Therefore, it is possible to solve the problem of durability such as blow-through of the discharge cooling gas and increase of the amount of oil in the system.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram having an oil separator for a refrigerator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a supercooling control valve of an oil return circuit.

FIG. 3 is a bottom view of a supercooling control valve.

FIG. 4 is an attachment state diagram of a supercooling control valve in a refrigerant circuit having a refrigerator oil separator according to another embodiment of the present invention.

FIG. 5 is a refrigerant circuit diagram of a conventional oil separator for a refrigerator.

FIG. 6 is a schematic view of an oil return mechanism of a refrigerant circuit of a conventional oil separator for a refrigerator.

FIG. 7 is a schematic view of an oil return mechanism of a refrigerant circuit of a conventional oil separator for a refrigerator.

[Explanation of symbols]

 11 Compressor 12 Oil Separator 13 Condenser 14 Receiver 15 Expansion Valve 16 Evaporator 17 Oil Return Circuit 31 Supercooling Control Valve 32 Case 33 Valve Mechanism 37 Valve Case Main Body 38 Outlet Hole 39 Inlet Hole 40 Fixed Valve 42 Moving Valve 43 Bellows 44 Capillary Tube 45 Space 46 Contact part

Claims (3)

[Claims] 1. A refrigerating machine oil separator provided in a refrigerating and air-conditioning refrigerant circuit detects the temperature and pressure of a fluid flowing out from the bottom of an oil separation mechanism, and uses the combination of the temperature and pressure in the refrigerant circuit. An oil separator for a refrigerator, which has a valve mechanism for causing the fluid to flow to the suction side of the compressor by keeping the valve open only when the value is equivalent to the supercooling region of the refrigerant. 2. The oil separator for a refrigerating machine according to claim 1, wherein the valve mechanism for detecting the temperature and pressure of the fluid flowing out from the bottom of the oil separation mechanism is a supercooling control valve by heat conduction with the suction part of the compressor. An oil separator for refrigerators, which is installed so that it can be cooled. 3. The refrigerating machine oil separator according to claim 1, wherein a valve mechanism for detecting the temperature and pressure of the fluid flowing out from the bottom of the oil separation mechanism is formed as a part of the suction section of the compressor, and is supercooled. An oil separator for a refrigerator, which is capable of cooling a control valve.