JP3489631B2 - Turbo refrigerator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbo refrigerator,
In particular, the present invention relates to a pressure equalizing pipe that connects an oil tank chamber and a compressor suction pipe, and a turbo refrigerator in which an opening / closing control valve is provided in the pressure equalizing pipe.

[0002]

2. Description of the Related Art Conventionally, a machine of this type has been disclosed in Japanese Utility Model Publication Sho 63-13.
As disclosed in Japanese Patent No. 429, the opening / closing control valve is closed at the start of the operation of the turbo chiller in order to prevent the occurrence of a forming phenomenon due to a sudden pressure reduction in the oil tank chamber and the accompanying decrease in hydraulic pressure due to entrainment of bubbles in the oil pump. Control was performed in which the compressor was started and the control valve was gradually opened after the operation of the compressor was started.

However, the conventional machine configured as described above has the following problems when the machine is started for the first time after being stopped for a long time. That is, during long-term stop, the oil in the oil tank is usually heated by the oil heater, and measures are taken to prevent the mixing of the refrigerant into the oil, but due to the uneven temperature in the oil tank,
Oil containing a large amount of refrigerant, that is, oil with low viscosity, may stay in a part of the oil tank.In such a case, degas the refrigerant dissolved in the oil before starting the compressor. It is desirable to start.

On the other hand, when the refrigerator is started, the cold water pump is operated prior to the operation of the compressor in conjunction with the refrigerator, and relatively low temperature cold water is passed through the evaporator of the refrigerator.
Although the temperature of the refrigerant inside the machine temporarily drops and the internal pressure of the refrigerator decreases, the solubility of the refrigerant in the oil decreases as the refrigerant pressure decreases, so the refrigerant component in the oil vaporizes and separates ( It becomes easy to be deaerated.

However, in the conventional refrigerator of this type, since the opening / closing control valve of the pressure equalizing pipe that connects the oil tank chamber and the compressor suction pipe is closed, the pressure in the oil tank chamber cannot be reduced, and therefore the oil in Could not degas the refrigerant of
There is a risk that the function of the bearing is impaired by supplying the bearing with the oil containing a large amount of the refrigerant component, that is, the oil whose viscosity is abnormally lowered. Further, even in a turbo refrigerator in which a pressure equalizing pipe that connects the oil tank chamber and the compressor suction pipe, a pressure equalizing pipe and an opening / closing control valve and a path that bypasses the control valve in parallel with the control valve are provided, Since the flow path area of the path that bypasses the valve is small, the refrigerant in the oil in the oil tank chamber cannot be quickly degassed, and the oil contains a large amount of the refrigerant component, that is, the viscosity drops abnormally. There is a risk that the oil will be supplied to the bearing and the function of the bearing will be impaired.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, facilitates degassing of the refrigerant from the oil tank, and recovers the viscosity of the oil to a proper viscosity by a simple control. An object of the present invention is to provide a highly-reliable refrigerator that can supply the above oil to the bearing.

[0007]

In order to solve the above-mentioned problems, in the present invention, a pressure equalizing pipe that connects the oil tank chamber and the compressor suction pipe and an opening / closing control valve are provided in the pressure equalizing pipe to start the operation of the compressor. A turbo compressor having an oil tank chamber, which has a control mechanism that sometimes closes the opening / closing control valve of the pressure equalizing pipe and gradually opens the opening / closing control valve of the pressure equalizing pipe after starting the operation of the compressor,
In a turbo refrigerator having an evaporator, a condenser, and a refrigerant path connecting them, the control mechanism controls opening / closing of the pressure equalizing pipe during operation of a chilled water pump before operation of a compressor and during independent operation of an oil pump. It is configured to open the valve. In the turbo refrigerator, the pressure equalizing pipe may be provided with a path that bypasses the control valve in parallel with the opening / closing control valve.

[0008]

According to the present invention, when the refrigerator is started, the opening / closing control valve of the pressure equalizing pipe that connects the oil tank chamber and the compressor suction pipe is opened during the independent operation of the oil pump performed before the operation of the compressor. By making use of the fact that the temperature of the refrigerant inside the machine temporarily decreases and the internal pressure of the refrigerator decreases during isolated operation, the refrigerant component in the oil can be vaporized and separated, It is possible to recover the viscosity and supply the oil of appropriate viscosity to the bearing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings, but the present invention is not limited to these. First Embodiment FIG. 1 is a schematic configuration diagram of an embodiment of the present invention. FIG. 2 is a time chart showing a control process of the device of FIG. In FIG. 1, 1 is a compressor, 2 is an evaporator, 3 is a condenser, 4
Is a compressor suction pipe, 5 and 6 are refrigerant passages, 7 is an evaporator heat transfer pipe, 8 is a condenser heat transfer pipe, and 9 is a cold water temperature sensor, and there is no difference from the configuration of a known turbo refrigerator. In the compressor 1, 11 is a main motor, 12 is a speed increaser, 13 is an impeller, and 1
4 is a suction vane, and 15 is an oil tank chamber, which are not different from the configuration of a known turbo refrigerator.

The turbo chiller to which the present invention is applied has, in addition to these components, a pressure equalizing pipe 16 that connects the oil tank chamber 15 and the compressor suction pipe 4 and an opening / closing control valve 17 to the pressure equalizing pipe 16. The opening / closing control valve 17 is provided when the compressor starts operating.
And a control mechanism for gradually opening the on-off control valve 17 after the compressor starts operating. In the present invention, the control valve 17 is controlled by the controller 18 at the time of starting the refrigerator as shown in FIG. The opening / closing control valve 17 of the pressure equalizing pipe is opened during the independent operation of the oil pump 20 before the start of the compressor operation, which is performed to raise the normal hydraulic pressure.

With this configuration, the opening / closing control valve 17 of the pressure equalizing pipe is opened during the independent operation of the oil pump 20 before the start of the compressor operation, which is performed to raise the normal hydraulic pressure when starting the refrigerator. Therefore, the chilled water pump is operated prior to the operation of the compressor in conjunction with the refrigerator, and cold water is passed through the evaporator of the refrigerator to temporarily lower the temperature of the refrigerant in the machine and reduce the internal pressure of the refrigerator. When the refrigerant component in the oil is vaporized and becomes more likely to be separated due to the decrease, the pressure in the oil tank chamber can be quickly reduced, and thus the refrigerant in the oil can be degassed, and the refrigerant in the oil can be degassed. The oil can be separated and removed to supply the oil of appropriate viscosity to the bearing. After that, as described in Japanese Utility Model Publication No. 63-13429, the opening / closing control valve is closed at the time of starting the compressor, the communication between the oil tank chamber and the compressor suction pipe is shut off, and the opening / closing control valve is started after the start of the compressor. By gradually opening 17, the refrigerator can be started while preventing the forming of the oil tank chamber.

Embodiment 2 FIG. 3 is a schematic block diagram of another example of the present invention. Also in FIG. 3, the control is performed according to the time chart showing the control process of the equipment of FIG. In FIG. 3, 1 is a compressor,
2 is an evaporator, 3 is a condenser, 4 is a compressor suction pipe, 5 and 6
Is a refrigerant path, 7 is an evaporator heat transfer tube, 8 is a condenser heat transfer tube, 9
Is a cold water temperature sensor, which is not different from the configuration of a known turbo refrigerator. Further, in the compressor 1, 11 is a main motor and 12
Is a gearbox, 13 is an impeller, 14 is a suction vane, 1
Reference numeral 5 denotes an oil tank chamber, which does not differ from the configuration of a known turbo refrigerator.

The turbo chiller to which the present invention is applied has, in addition to these components, a pressure equalizing pipe 16 for communicating the oil tank chamber 15 with the compressor suction pipe 4, and an opening / closing control valve 17 for the pressure equalizing pipe 16. A path 22 bypassing the control valve 17 and a throttle mechanism 23 are provided in parallel with the control valve 17, and the opening / closing control valve 17 is closed at the start of operation of the compressor, and the opening / closing control valve is gradually increased after the start of operation of the compressor. In the present invention, the control valve 17 is connected to the controller 18
As a result, at the time of starting the refrigerator, as shown in FIG. 2, when the oil pump 20 is independently operated before the compressor operation is started in order to raise the normal hydraulic pressure, the opening / closing control valve 17 for the pressure equalizing pipe 17 is operated.
It is configured to open.

With this configuration, the opening / closing control valve 17 of the pressure equalizing pipe is opened during the independent operation of the oil pump 20 before the start of the compressor operation, which is performed to raise the normal hydraulic pressure at the time of starting the refrigerator. Therefore, prior to the operation of the compressor in conjunction with the refrigerator, the cold water pump is operated and cold water is passed through the evaporator of the refrigerator, and the temperature of the refrigerant inside the machine temporarily drops and the internal pressure of the refrigerator is reduced. When the refrigerant component in the oil is vaporized and is easily separated, the pressure in the oil tank chamber can be quickly reduced, and thus the refrigerant in the oil can be degassed. It is possible to separate and remove the refrigerant component and supply the oil of appropriate viscosity to the bearing.

After that, as described in Japanese Utility Model Publication No. 63-13429, at the time of starting the compressor, the opening / closing control valve is closed to limit the communication between the oil tank chamber and the compressor suction pipe, leaving only the orifice 23. Then, by gradually opening the opening / closing control valve 17 after the start of the start, it is possible to smoothly start the refrigerator while preventing the forming of the oil tank chamber. Further, although the embodiment of the present invention illustrates that the opening / closing control valve 17 is immediately closed at the time of starting the compressor, even if there is some delay in consideration of the operating time of the opening / closing mechanism, it is also possible to use the actual opening / closing valve 63-13429. In accordance with the example of the publication, before starting the suction vane after starting,
It may be configured to complete the closing operation of the valve.

[0016]

According to the present invention, in order to prevent a forming phenomenon at the time of starting, a pressure equalizing pipe that connects the oil tank chamber and the compressor suction pipe is provided with an opening / closing control valve at the pressure equalizing pipe, and when the compressor is started, In a turbo chiller having a control mechanism that closes the opening / closing control valve of the pressure equalizing pipe and gradually opens the opening / closing control valve of the pressure equalizing pipe after starting the operation of the compressor, this is usually performed to raise the hydraulic pressure. By configuring the open / close control valve of the pressure equalizing pipe to open when the oil pump operates independently before starting the compressor operation, even when the refrigerator is started after a long-term stop, oil with an appropriate viscosity is applied to the bearing. Since it can be supplied, a more reliable turbo refrigerator can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a turbo refrigerator according to the present invention.

FIG. 2 is a time chart showing a control operation of the turbo refrigerator according to the present invention.

FIG. 3 is a schematic configuration diagram showing another example of the turbo refrigerator of the present invention.

[Explanation of symbols]

1: Compressor, 2: Evaporator, 3: Condenser, 4: Compressor suction pipe, 5, 6: Refrigerant path, 7: Evaporator heat transfer pipe, 8: Condenser heat transfer pipe, 9: Cold water temperature sensor, 11 : Main motor, 1
2: gearbox, 13: impeller, 14: suction vane,
15: Oil tank chamber, 16: Pressure equalizing pipe, 17: Open / close control valve, 18: Controller, 20: Oil pump, 21:
Bypass path, 23: throttle mechanism.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F25B 1/053 F25B 1/00 351

Claims (2)

(57) [Claims] 1. A pressure equalizing pipe that connects an oil tank chamber and a compressor suction pipe, and an opening / closing control valve is provided in the pressure equalizing pipe, and the opening / closing control valve of the pressure equalizing pipe is closed when the compressor is started to start the compressor operation. In a turbo refrigerator having a control mechanism for gradually opening the opening / closing control valve of the pressure equalizing pipe afterward, a turbo compressor having an oil tank chamber, an evaporator, a condenser, and a refrigerant path connecting these. Further, the control mechanism is configured to open the opening / closing control valve of the pressure equalizing pipe when the oil pump is operating independently during operation of the cold water pump before the start of operation of the compressor. 2. The turbo chiller according to claim 1, wherein the pressure equalizing pipe is provided with a path that bypasses the control valve in parallel with the opening / closing control valve.