JPS61246556A - Method of operating refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has an evaporator, a condenser, a compressor, and a main motor for driving the compressor, and cools the main motor with condensed refrigerant liquid. The present invention relates to a method of operating a refrigerator as described above.

[Conventional technology]

This main motor cooling system, as disclosed in Japanese Patent Application Laid-open No. 110963/1983, uses the heat recovered when cooling the internal heat of the main motor to be released directly into the cooling water in the condenser. This is a cooling method that does not use compression power and is effective in saving energy for refrigerators. In this type of system, a refrigerant pump is provided to supply a refrigerant liquid for cooling to the main motor.

[Problem that the invention seeks to solve]

However, in such a refrigerator, cavitation may occur in the refrigerant pump at the time of startup, resulting in vibration and damage to the refrigerant pump.

Normally, the refrigerant pump used for such applications is a closed type with bearings lubricated by refrigerant liquid in order to improve the airtightness of the refrigerator, but under the cavitation phenomenon described above, the refrigerant If the bearing is not sufficiently lubricated by the liquid and is exposed to such a phenomenon for a long period of time, there is a problem that the durability of the refrigerant pump is adversely affected.

The present invention solves the problems of the conventional methods as described above, prevents the occurrence of cavitation in the refrigerant pump, improves the durability of the refrigerant pump, and provides a method for operating a refrigerator with high reliability of the cooling effect. The purpose is to provide.

[Means for solving problems]

In order to achieve the above object, the inventors conducted repeated experiments and research, and based on the knowledge obtained at that time, the present invention was made.

In other words, the inventors' research revealed that for a certain period of time when the refrigerator is started, there is not enough refrigerant to be condensed in the condenser, and as a result, the amount of refrigerant required for suction by the pump is insufficient, causing cavitation. It was confirmed that

At startup, the amount of refrigerant liquid required for suction by the refrigerant pump cannot be obtained within 1-minutes, so cavities are likely to occur, but the main motor starts without the refrigerant pump being operated. For example, 10-15 hours
It was confirmed that the internal temperature of the main motor did not rise rapidly for about a minute, and no cooling problems occurred.

Once started, if the refrigeration load is sufficient, a large amount of refrigerant will condense in the condenser and refrigerant liquid will be obtained, and the refrigerant pump will be able to operate without cavitation. Therefore, the refrigerant pump and the main motor do not necessarily need to be operated in conjunction with each other even during startup; in practice, the main motor is operated first while the refrigerant pump is stopped, and the refrigerant pump is turned on when the refrigerant level is secured. It was confirmed that it is possible to operate the refrigerant pump in a desirable operating mode to extend the life of the refrigerant pump.

Based on these findings, the present invention aims to extend the life of the refrigerant pump and to maintain smooth cooling of the main motor by first starting the main motor at startup, and then starting the refrigerant pump when the load becomes sufficiently large. It is designed to start.

That is, the present invention provides an evaporator, a condenser, a compressor, and a main motor 1 for driving the compressor, as a means to solve the above-mentioned conventional method. and a capacity control device for the compressor, which communicates the internal space of the cough main motor with the condenser, and introduces the refrigerant liquid condensed in the condenser into the internal space of the main motor via a refrigerant pump. In the operating method of the refrigerator, the main motor is first started at startup, the refrigerant pump is not started, and the refrigerant pump is started when the opening degree of the capacity control device reaches a predetermined opening degree or more. It is an object of the present invention to provide a method of operating a refrigerator characterized by starting the refrigerator.

〔Example〕

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

In FIG. 1, 7 is a compressor, which is driven by the main motor 11 via a speed increaser 8110. Reference numeral 9 denotes a suction vane as a capacity control device, and the opening degree of the vane is controlled by an actuator 17 to control the capacity of the compressor 7, that is, the capacity of the refrigerator.

The condenser 3 and the evaporator 1 are formed within one can body. The condenser 3 has an inlet side connected to the discharge side of the compressor 7, and an outlet side equipped with a float chamber 12 in which condensate is stored, and communicates with the bottom of the evaporator 1 via a float valve 16. . The evaporator 1 is connected via a passage 5 to the suction side at a pressure of $1117.

4 is a cooling water passage, and 2 is a cold water passage.

The refrigerant liquid storage portion of the float chamber 12 is connected to the internal space of the main motor 11 via a passage 14, a refrigerant pump 20, a passage 14', and a spray nozzle 15.

Reference numeral 21 denotes a passage that communicates the internal space of the main motor 11 and the condenser 3.

45 is a temperature detector that detects the cold water outlet temperature.

Is 18 legal? This is an operation panel as an Illjm system, and is adapted to operate the refrigerant pump 20, actuator 17, etc. as described later in response to a chilled water outlet temperature signal as a load signal, a suction vane opening signal, etc.

In addition, the operation panel 18 receives a signal of the chilled water outlet temperature or the coolant outlet temperature as a load signal, and outputs a signal to the actuator 17 to set the chilled water outlet temperature to a predetermined temperature, thereby operating the suction vane 9. capacity control.

The refrigeration cycle will be explained with reference to FIG. The refrigerant evaporated in the evaporator 1 is sucked into the compressor 7 via the passage 5, is compressed, flows into the condenser 3, condenses, flows into the float chamber 12, is depressurized by the float valve 16, and then evaporates again. It flows into container 1 and forms a refrigeration cycle.

Next, the cooling cycle of the main motor 11 will be explained. The internal space of the main motor 11 is communicated with the condenser 3 through a passage 21, and the refrigerant for cooling the main motor 11 is sucked from the float chamber 12 of the condenser 3 through the passage 14 by the refrigerant pump 20, and is pressurized into the passage 14. ' is supplied to the spray nozzle 15 and sprayed inside the motor. The sprayed refrigerant takes away the internal heat generation of the main motor 11 and cools the inside of the main motor 11 while evaporating itself and passes through the passage 21 to the condenser 3.
The refrigerant flows into the float chamber 12, is cooled by the cooling water in the cooling water passage 4, condenses, becomes a refrigerant liquid, and returns to the float chamber 12 again. The interior of the main motor 11 is cooled by repeating the above cooling cycle.

Next, the control of this embodiment will be explained.

In FIG. 1, the actuator 17 is provided with a detection mechanism that detects the operation amount, that is, the opening degree of the suction vane 9, which serves as the operation part of the capacity control mechanism, that is, the capacity control valve, and sends a detection signal to the operation panel 18. It is configured to control the operation of the refrigerant pump 20 and the main motor 11. That is, at the time of starting, the main motor 11 is first started, and when it is detected that the suction bay 79 has reached a predetermined opening or more, the signal is sent to the operation panel to start the refrigerant pump 20.

Figure 2 is an electrical wiring diagram for the operation panel and the refrigerant pump 20.
The electromagnetic switch 25 is energized via the contact 23 which becomes non-contact when the suction vane 9 as a capacity control valve is in a fully closed state. Here, the fully open state refers to a centrifugal compressor as shown in Fig. 1 in a centrifugal compressor that uses suction vane 9 as a capacity control valve. When it is 0%, a range of about 2 to 5% from O is selected. For example, when a range of opening degree is selected from 0 to 2%, the contact 23 is set to be open when the opening degree is within the range of 0 to 2%, and closed when the opening degree exceeds 2%. Further, when the fully closed state range is selected to be an opening degree of 0 to 5%, the contact 23 is set to be open in the opening degree range of 0 to 5%, and closed when the opening degree exceeds 5%.

FIG. 3 shows a mechanism for detecting the fully closed state of the capacity control valve. The contact 23 is built into a microswitch 27, and the microswitch 27 is operated by a cam 24 connected to the shaft of the suction vane 9. When the suction vane 9 is fully open (for example, the degree of opening is within the range of 0 to 2%), the cam 24 does not press the microswitch 27, and the built-in contact 23 is in a non-contact state. Next, when the refrigerator is operated and the suction vane 9 opens, for example, the degree of opening exceeds 2% and escapes from the fully closed state, the microswitch 27 is pushed by the cam 24, the contact 23 is connected, and the signal is operated. The electromagnetic switch 25 is excited within the panel 18,
Refrigerant pump 20 is operated.

With this configuration, when the suction vane 9 is in a fully closed state, such as when starting the refrigerator, the operation of the refrigerant pump 20 is suspended and the refrigerator starts operating to ensure that sufficient load is applied. When the suction vane 9 opens to a predetermined opening degree and sufficient refrigerant liquid flows into the float chamber 12, the refrigerant pump 20 begins to operate.

〔Effect of the invention〕

According to the present invention, it is possible to prevent the cavity silane phenomenon of the refrigerant pump caused by insufficient refrigerant liquid amount, which tends to occur when the capacity control valve (for example, suction vane) of the capacity control device is fully open at the time of startup. This prevents the refrigerant pump from operating without sufficient lubrication of the bearings, thus improving the durability of the refrigerant pump for cooling the motor, and also improving the cooling of the refrigerator motor by the action of the refrigerant pump. It is possible to provide a method of operating a refrigerator that improves the reliability of the device, and has extremely great practical effects.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention; Fig. 1 is a cycle explanatory diagram of one embodiment, Fig. 2 is an electrical wiring diagram showing its sequence circuit, and Fig. 3 is an opening detector of the capacity control mechanism. FIG. l...evaporator, 2...cold water passage, 3...condenser,
4... Cooling water passage, 5... Passage, 7... Compressor,
9... Succinim vane, 10... Speed increaser, 11.
...Main motor, 12...Float chamber, 14.14'.
... Passage, 15... Spray nozzle, 16... Float valve, 17... Actuator, 18... Operation panel, 20... Refrigerant pump, 21... Passage, 23...
Contact, 24...Cam, 25...Electromagnetic switch, 27.
...Microsinch. Patent applicant: EBARA CORPORATION Representative Patent Attorney: Masayuki Takagi Representative Patent Attorney: Yakushi Minoru Representative Patent Attorney: Yori 1) Takaji
Department

Claims (1)

[Claims] 1. An evaporator, a condenser, a compressor, a main motor for driving the compressor, and a capacity control device for the compressor, the internal space of the main motor communicating with the condenser. In this method of operating a refrigerator, the refrigerant liquid condensed in the condenser is introduced into the internal space of the main motor via a refrigerant pump. A method for operating a refrigerator, characterized in that the refrigerant pump is not started, but the refrigerant pump is started when the opening degree of the capacity control device reaches a predetermined opening degree or more.