JP3615342B2 - Refrigeration equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigeration apparatus using a hermetic compressor body.
[0002]
[Prior art]
Conventionally, as shown in FIG. 2 , a closed refrigerant main flow path I including an oil-cooled compressor body 11, an oil separator / recoverer 12, a condenser 13, a first expansion valve 14 and an evaporator 15, and an oil A first bypass flow path II for guiding a part of the refrigerant gas that has left the separation / recovery unit 12 and reaches the condenser 13 to a portion of the main flow path I between the evaporator 15 and the compressor body 11; A continuous operation type refrigeration apparatus including an oil supply passage III that guides oil in an oil sump 16 at a lower portion of the recovery unit 12 to an oil injection point in the compressor body 11 is known.
The first bypass channel II is provided with an on-off valve 17 and a flow rate adjusting valve 18, and the oil supply channel III is provided with an oil cooler 19.
[0003]
In this refrigeration apparatus, if the refrigeration apparatus cannot be stopped even if the refrigeration load is reduced, the partial load operation of the compressor body 11 is first performed. If it is still insufficient and it is necessary to cope with a lower refrigeration load, the on-off valve 17 is opened, and the flow rate is adjusted by the flow rate adjusting valve 18 while a part of the refrigerant gas discharged from the compressor body 11 is discharged to the compressor. By returning to the suction side of the main body 11, a low load capacity is ensured and continuous operation is continued.
[0004]
[Problems to be solved by the invention]
In the above-described conventional refrigeration apparatus, even if the compressor main body 11 may be of the type in which the rotor for gas compression and the drive unit thereof are formed by completely separate casings, both of them are accommodated in a single casing. In the case of a sealed type, a problem arises. That is, the high-temperature refrigerant gas is bypassed from the compressor body 11 to the compressor body 11 during low-load continuous operation, and the refrigerant gas directly contacts the drive section of the compressor body 11, that is, the motor. There arises a problem that continuous operation becomes impossible due to overheating.
The present invention has been made with such conventional problems as an object, and an object of the present invention is to provide a refrigeration apparatus capable of continuous operation at a low load capacity.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an oil-cooled rotor that compresses gas and a motor that is a driving unit of the rotor that is housed in a single casing, a hermetic compressor body, an oil separator and a condenser. The main flow path of the closed refrigerant including the condenser, the first expansion valve, and the evaporator, the portion of the main flow path that exits the oil separation and recovery unit and reaches the condenser, and the evaporator 2 in the main flow path. Provided between the secondary side and the portion between the compressor body, the first on-off valve is interposed, and cannot be stopped even if the cooling load is reduced, the partial load operation of the compressor body Is still inadequate and it is necessary to cope with a lower cooling load, the first on-off valve is opened, and the refrigerant gas before the oil separation / recovery device and the condenser is reached. A first bypass that guides the portion to a portion of a main flow path between the evaporator and the compressor body And the flow path, the refrigeration system including an oil supply passage for guiding the lower portion of the oil reservoir oil of the oil separating and collecting device to lubricate portions in the compressor body, opened and closed in conjunction with the first on-off valve A second on-off valve is interposed, and when the second on-off valve is opened , the refrigerant in the portion of the main flow path between the condenser and the first expansion valve is gasified by the second expansion valve. Thus, a second bypass flow path that leads to any part of the main flow path from the evaporator to the compressor body is provided.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
Figure 1 shows a refrigeration apparatus according to the present invention, portions which are common to each other and the freezing apparatus shown in FIG. 2 will be omitted given the same numbers.
In this refrigeration apparatus, the hermetic compressor body 1 is used, and the refrigerant in the portion of the main flow path I between the condenser 13 and the first expansion valve 14 is made into a gas state by the second expansion valve 2, and the evaporator 15. Is provided with a second bypass passage IV that leads to any part of the main passage I extending from the main body I to the compressor body 1.
In addition, when the first bypass flow path II is opened in the second bypass flow path IV and the low load capacity operation is performed, the second bypass flow path IV is opened in conjunction with this, and when the low load operation is not performed, the second bypass flow path II is coupled. An on-off valve 3 is provided.
[0007]
With such a configuration, at the time of low load capacity operation, the refrigerant gas having a low temperature is led from the second bypass flow path IV into the compressor main body 1 to cool the motor, and continuation is possible.
Note that the above-described sealed type may be referred to as a semi-sealed type, and the expression “sealed type” in this specification includes this semi-sealed type, and a rotor that compresses gas and a motor that is a driving unit thereof are single. It means the type housed in the casing.
[0008]
【The invention's effect】
As is apparent from the above description, according to the present invention, an oil-cooled rotor that compresses gas and a motor that is a drive unit of the rotor are enclosed in a single casing, and an oil separation and recovery unit is provided. A closed refrigerant main flow path including a condenser, a condenser, a first expansion valve, and an evaporator; a portion of the main flow path that exits the oil separation and recovery unit before reaching the condenser; and the evaporation in the main flow path. Provided between the secondary side of the compressor and the portion between the compressor body, the first on-off valve is interposed, and cannot be stopped even if the cooling load is reduced. If the partial load operation is still insufficient and it is necessary to cope with a lower cooling load, the refrigerant before the first on-off valve is opened and leaves the oil separation and recovery device before reaching the condenser Part of the gas is led to a part of the main flow path between the evaporator and the compressor body In refrigeration system including 1 and the bypass passage, and an oil supply passage for guiding the lower portion of the oil reservoir oil of the oil separating and collecting device to lubricate portions in the compressor body, in conjunction with the first on-off valve A second on-off valve that opens and closes is provided, and when the second on-off valve is opened , the refrigerant in the portion of the main flow path between the condenser and the first expansion valve is gasified by the second expansion valve. A second bypass flow path that leads to any part of the main flow path from the evaporator to the compressor main body is provided.
For this reason, at the time of low load capacity operation, the refrigerant gas having a low temperature is led from the second bypass channel into the compressor body, the motor is cooled, and the continuous operation becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a refrigeration apparatus according to a first invention of the present application.
FIG. 2 is a diagram showing an overall configuration of a conventional refrigeration apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor main body 2 2nd expansion valve 12 Oil separation collection | recovery device 13 Condenser 14 1st expansion valve 15 Evaporator 16 Oil sump part I Main flow path II 1st bypass flow path
III Oil supply channel IV Second bypass channel

Claims (1)

An oil-cooled rotor for gas compression and a motor as a driving part thereof include a hermetic compressor body, an oil separator / collector, a condenser, a first expansion valve, and an evaporator housed in a single casing. A closed refrigerant main flow path;
Provided between the portion of the main flow path that exits the oil separation and recovery unit and reaches the condenser, and the portion of the main flow path between the secondary side of the evaporator and the compressor body, 1 On-off valve is interposed, and cannot be stopped even if the cooling load decreases, and even if the partial load operation of the compressor body is performed, it is still insufficient, and it is necessary to cope with a lower cooling load. In this case, the first on-off valve is opened, and a part of the refrigerant gas that has left the oil separation and recovery unit and reaches the condenser is transferred to a portion of the main flow path between the evaporator and the compressor body. A first bypass channel leading;
In a refrigeration apparatus comprising an oil supply passage for guiding oil in a lower oil reservoir of the oil separator / collector to an oil supply location in the compressor body,
A second on-off valve that opens and closes in conjunction with the first on-off valve is interposed, and when the second on-off valve is opened , the portion of the main flow path between the condenser and the first expansion valve is opened . A refrigeration apparatus comprising: a second bypass flow path that leads a refrigerant to a gas state by a second expansion valve and leads to any part of a main flow path from the evaporator to the compressor body.

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