JPH04161761A - Freezer device - Google Patents

Abstract

PURPOSE:To prevent a reduction of freezing capacity or prevent a discharging temperature of gaseous refrigerant got from a compressor from being raised by a method wherein a control means controls a solenoid valve so as to open it during an operation of a refrigerant circuit only for a period in which oil is stored at a storing part or the oil is kept in an oil return pipe. CONSTITUTION:Gaseous refrigerant compressed by a compressor 1 and discharged from it is fed to an oil separator 3. The oil separator 3 is constructed such that a storing part 23 for storing separated oil is provided and the oil passes from an oil discharging hole 25 at a lower part of the storing part 23 through an oil return pipe 14 and a solenoid valve 15 placed in the midway of the oil return pipe and returned back to the compressor 1. This solenoid valve 15 is opened only for a period in which the oil is stored at the storing part 23 of the oil separator 3 under an operation of a control means 26 or in which the oil is present within the oil return pipe 14. Accordingly, it is possible to prevent the gaseous refrigerant discharged from the compressor 1 from being short-circuited at the oil separator 3, solenoid valve 15 and oil return pipe 14 to a suction line of the compressor and from flowing. Due to this arrangement, it is possible to prevent a freezing capacity from being reduced or a temperature of the gaseous refrigerant discharged from the compressor from being raised.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a refrigeration system, and more particularly to a method for returning oil separated by an oil separator provided in a compressor discharge line to a compressor suction line. The present invention relates to a refrigeration system configured as follows.

BACKGROUND OF THE INVENTION A refrigeration system equipped with such an oil separator is disclosed, for example, in Japanese Utility Model Application No. 62-85876.

When a so-called float type oil separator is used as this oil separator, the oil separated from the gas refrigerant from the compressor is stored in a storage section of a container, and when the amount of storage detected by the float exceeds a predetermined value. When this happens, the stored oil is returned to the suction line of the compressor via the oil return pipe until the stored amount reaches a predetermined value. In a configuration using such a float type oil separator, oil is always stored in the container, so there is a risk that the discharged gas refrigerant from the compressor will bypass the compressor via the oil return pipe and suction line. Therefore, the refrigeration capacity will not decrease,
Further, the temperature of the gas refrigerant discharged from the compressor is prevented from rising abnormally.

Instead of a float type oil separator with such a structure,
A gas refrigerant containing oil from a compressor collides with a wire mesh installed inside the container, and the separated oil drips onto the bottom of the container, forming an oil drainage hole at the bottom of the container. It is also possible to use an oil separator configured to return this oil from the oil drain hole to the suction line of the compressor via the oil return pipe, which is simpler in configuration than a float type oil separator. I can,
Maintenance can be made easier. At this time, if no oil is stored in the container, the gas refrigerant discharged from the compressor during operation passes through the oil separator's oil drain hole and oil return pipe, and then short-circuits to the suction line. As a result, the refrigerating capacity decreases, and the discharge temperature of the gas refrigerant from the compressor increases.

Problems to be Solved by the Invention The purpose of the present invention is to prevent the oil separator from reducing the refrigerating capacity or increasing the discharge temperature of the gas refrigerant from the compressor, thereby enabling stable operation. The object of the present invention is to provide a refrigeration device that provides

Means for Solving the Problems The present invention provides a compressor 1 for compressing a gas refrigerant, and a compressor 1 for compressing a gas refrigerant.
A condenser 6 that condenses the gas refrigerant compressed in II to turn it into a liquid refrigerant, an expansion means 8 that expands the liquid refrigerant condensed in the condenser 6, and an expansion means 8 that evaporates the expanded liquid refrigerant. It has a refrigerant circuit configured by sequentially connecting in series an evaporator 9 that converts it into a gas refrigerant, and an oil separator 3 that separates oil contained in the gas refrigerant discharged from the compressor 1.
The oil separated by this oil separator 3 is transferred to an oil return pipe 14
In the refrigeration system, the oil separator 3 has a storage section 23 for storing separated oil, and an oil drain hole 25 is formed in the lower part of this storage section 23, and the oil drain hole 25 is formed in the lower part of the storage section 23. The oil return pipe 14 is connected to the hole 25, and further includes a solenoid valve 15 interposed in the middle of the oil return pipe 14, and a control means 26 for controlling the solenoid valve 15. A refrigeration system characterized in that the solenoid valve 15 is controlled to be opened only during a period in which oil is stored in the storage section 23 or in the oil return pipe 14 during operation of the refrigerant circuit. It is.

According to the present invention, the gas refrigerant compressed and discharged from the compressor is guided to the oil separator, and the oil separator has a storage section for storing separated oil, and the lower part of the storage section The oil is returned to the compressor from the oil drain hole through the oil return pipe and the solenoid valve interposed in the middle of the oil return pipe. Only during the period when oil is stored or there is oil in the oil return pipe,
In other words, it is opened only during the period when the gas refrigerant from the compressor does not bypass through the oil separator and oil return pipe. Therefore, the gas refrigerant discharged from the compressor passes through the oil separator,
This can prevent the oil from flowing through the solenoid valve and oil return pipe into the suction line of the compressor. Therefore, a decrease in the refrigerating capacity is prevented. This also prevents the temperature of the gas refrigerant discharged from the compressor from rising. In this way, it is possible to expand the usage limit of the refrigeration system. In this way, stable refrigeration operation can be continued.

Embodiment FIG. 1 is an overall system diagram of an embodiment of the present invention. In the refrigeration system, a gas refrigerant compressed by a compressor 1 is led from a pipe 2 to an oil separator 3, where oil contained in the gas refrigerant is separated, and the gas refrigerant is passed from a pipe 4 to a four-way switching valve. 5, the liquid refrigerant is led to a condenser 6, where it is condensed, and the liquid refrigerant condensed here is expanded from a pipe line 7 by an expansion means 8. The gas refrigerant from the evaporator 9 is supplied to the accumulator 12 from the pipe line 10 via the four-way switching valve 5 and further from the pipe line 11. The gas refrigerant from the accumulator 12 is sucked into the compressor 1 through a pipe line 13 including a riser pipe 131 extending vertically.

The oil separated from the gas refrigerant in the oil separator 3 is guided from the oil return pipe 14 to the pipe line 13 and returned to the compressor 1. A solenoid valve 15, a filter 16 for removing dust, and a capillary pipe 17 are interposed in the middle of the oil return pipe 14.

FIG. 2 is a sectional view showing the structure of the oil separator 3. A partition plate 19 is provided in the casing 18 of this oil separator 3, and a passage 20 through which the oil-containing gas refrigerant from the pipe line 2 passes
is formed by bending. A collision plate 22 is attached to the partition plate 19. When the gas refrigerant collides with the collision plate 22, oil contained in the gas refrigerant collides with the collision plate 22, and the oil is stored in a storage section 23 in the lower part of the housing 18. is formed and stored. The gas refrigerant from which the oil has been separated is guided from the pipe 4 to the condenser 6 via the four-way selector valve 5 as described above. An oil drain hole 25 is formed at the bottom of the housing 18, which is the lower part of the storage section 23.

The oil return pipe 14 is connected to this oil drain hole 25 .

The opening and closing of the solenoid valve 15 is controlled by a control means 26 realized by, for example, a microcomputer.

The control means 26 opens the solenoid valve 15 only during a period in which the gas refrigerant from the compressor 1 does not bypass the oil separator 3 and the oil return pipe 14, and keeps it closed during the remaining period. The period during which the solenoid valve 15 is opened is, for example, (a) a predetermined time at the time of startup of the refrigeration system;
(b) for a predetermined period of time, e.g., 5 minutes, each time the refrigeration equipment continues to operate continuously for a predetermined period of time, e.g., 20 minutes, or (c) for defrost operation by reverse cycle. At the start, it is a predetermined period of time, for example 3 minutes. The reverse cycle defrost operation in (c) above means that the four-way switching valve 5 is switched, the gas refrigerant from the pipe 4 is guided to the evaporator 9 via the pipe 10, and condensed. This is an operation in which the liquid refrigerant is evaporated and the refrigerant is circulated from the pipe 11 to the compressor 1 via the accumulator 12 and the pipe 13. At the start of such a defrosting operation, a predetermined period of time is set, for example, as described above. During the three minute period, the liquid refrigerant remaining in the condenser 6 returns from the accumulator 12 to the compressor 1, so that the oil contained in the gas refrigerant discharged from the compressor 1 into the pipe line 2 increases. Each of the above periods (a), (b), (C
), oil is stored in the storage portion 23 in the housing 18 of the oil separator 3, and at this time, the oil drain hole 25 and the oil return pipe 14 are blocked by the stored oil, so that the passage 20 in the housing 18 is blocked. During each such period, the solenoid valve 15 is opened so that no gas refrigerant is bypassed from the line 13 to the compressor 1 via the oil return pipe 14. This prevents a decline in refrigeration capacity,
Further, it is possible to prevent the temperature of the gas refrigerant discharged from the pipe line 2 from rising, and the usage limit of the refrigeration apparatus can be expanded, and stable refrigeration operation can be continued.

The oil return pipe 14 is connected to a vertically extending riser pipe 131 that forms part of the pipe line 13 that is connected to the outlet of the accumulator 12 . As a result, the oil return pipe 14
When the refrigeration operation is stopped while the oil is being returned through the riser pipe 131, the oil returns to the accumulator 12 through the riser pipe 131. Therefore, when restarting operation, it is possible to prevent the oil from entering the compressor 1 as a separate liquid rather than as a gas refrigerant, and damage to the compressor 1 can be prevented. .

Although the oil separator 3 shown in FIG. 2 is configured so that the gas refrigerant containing oil collides with the collision plate 22 and the oil drips and is stored, other embodiments of the present invention The oil separator may be configured such that the oil-containing gas refrigerant collides with a collision plate such as a wire mesh, and the oil is collected and dripped, or may have other configurations.

Effects of the Invention As described above, according to the present invention, oil contained in a gas refrigerant from a compressor is separated by an oil separator, and this oil separator has a storage section for storing the separated oil. An oil drain hole is formed at the bottom of the storage part, and the oil from this oil drain hole is
The oil is returned to the suction line of the compressor via a solenoid valve interposed in the middle of the return pipe, and this solenoid valve is controlled by a control means.
Since the solenoid valve is configured to open only during the period when the gas refrigerant from the compressor is not bypassed through the oil separator and oil return pipe, it prevents a decrease in the refrigerating capacity and also prevents the gas refrigerant discharged from the compressor from decreasing. This will prevent temperature rises, expand the usage limits of the refrigeration equipment, and enable continued stable operation.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of an embodiment of the present invention, and FIG. 2 is a sectional view showing the configuration of an oil separator 3. DESCRIPTION OF SYMBOLS 1... Compressor, 3... Oil separator, 5... Four-way switching valve, 6... Condenser, 8... Expansion means, 9... Evaporator,
12...Accumulator, 14.Oil return pipe, 15...
Solenoid valve, 18...housing, 19...partition plate,
22... Collision plate, 23... Storage section, 25. Oil drain hole,
26...Controlling Agent Patent Attorney Kei Saikyo Figure 1 Figure 2

Claims (1)

[Claims] (1) A compressor 1 that compresses gas refrigerant, and a condenser 6 that condenses the gas refrigerant compressed by this compressor 1 into liquid refrigerant.
, an expansion means 8 that expands the liquid refrigerant condensed in the condenser 6, and an evaporator 9 that evaporates the liquid refrigerant expanded in the expansion means 8 to turn it into a gas refrigerant, which are successively connected in series. The oil separator 3 has a refrigerant circuit and separates oil contained in the gas refrigerant discharged from the compressor 1, and the oil separated by the oil separator 3 is passed through an oil return pipe 14. In the refrigeration system, the oil separator 3 has a storage section 23 for storing separated oil, and an oil drain hole 25 is formed in the lower part of the storage section 23.
The oil return pipe 14 is connected to the oil drain hole 25, and further includes a solenoid valve 15 interposed in the middle of the oil return pipe 14, and a control means 26 for controlling the solenoid valve 15. is characterized in that during operation of the refrigerant circuit, the solenoid valve 15 is controlled to be opened only during a period in which oil is stored in the storage section 23 or oil is in the oil return pipe 14. Refrigeration equipment.