JP3306958B2 - Lubricating oil adjusting device for refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for adjusting lubricating oil for a refrigerator used in an air conditioner or the like.

[0002]

2. Description of the Related Art A centrifugal chiller is used as a chiller used in an air conditioner in a building. It is composed of a turbo compressor, a drive motor, a heat exchanger (evaporator, condenser), a transmission device, a bleed air recovery device, a lubrication device, and the like.
Among these, the lubrication device aims to improve the lubrication of the moving parts of the compressor and the sealing effect of the compressor section. For this purpose, it is necessary to optimally control the viscosity of the lubricating oil. is there.

[0003] However, the refrigerant is mixed with the lubricating oil during the operation of the refrigerator, and is stirred and melted into the lubricating oil. As a result, the temperature of the lubricating oil gradually decreases, adversely affecting the operation of the compressor, and the capacity of the refrigerator. Had been lowered. Then, when this state progresses, the protection device operates to stop the operation of the refrigerator, which causes a situation in which air conditioning is disabled. Therefore, in order to maintain the viscosity of the lubricating oil properly, the amount of refrigerant mixed is calculated based on the weight of the lubricating oil in the tank and the volume calculated from the liquid level of the lubricating oil in the tank, and this is defined as A lubricating oil adjusting device has been provided in which a lubricating oil is heated by a heating means to evaporate and remove a required amount of refrigerant when the value exceeds the value (see JP-A-2-40466).

[0004]

However, in the above-described adjusting device, the lubricating oil in the tank is affected by dynamic disturbance such as inflow of the lubricating oil into the tank and outflow of the lubricating oil from the tank. Since the surface was disturbed, the liquid level could not be detected with high accuracy, and the amount of refrigerant mixed in could not be accurately grasped. As a result, the viscosity of the lubricating oil could not be maintained at an optimum level.

Accordingly, an object of the present invention is to provide a lubricating oil for a refrigerator capable of solving the above-mentioned technical problems, accurately ascertaining the amount of refrigerant mixed in, and maintaining an optimum viscosity of the lubricating oil. An adjusting device can be realized.

[0006]

According to a first aspect of the present invention, there is provided a refrigerating machine lubricating oil adjusting device for detecting a temperature of a compressor lubricating oil stored in a tank. Detecting means, pressure detecting means for detecting the pressure of the lubricating oil, a temperature and pressure of the lubricating oil, a data storage unit that stores in advance the relationship data between the amount of refrigerant mixed into the lubricating oil,
Based on the detected temperature and pressure of the lubricating oil and the related data stored in the data storage unit, a mixed refrigerant amount calculating unit that calculates the mixed refrigerant amount, a heating unit that heats the lubricating oil in the tank, Comparing the mixed refrigerant amount calculated by the refrigerant amount calculation unit with a preset threshold value, and when the threshold value is exceeded, outputting a signal to the heating means to heat the lubricating oil in the tank; And a mixed refrigerant amount adjusting unit for setting the mixed refrigerant amount to a threshold value or less.

[0007] The heating means may comprise an electric heater. The heating means may use the gas discharged from the compressor as a heat source. In order to achieve the above object, a refrigerator lubricating oil adjusting device according to claim 4 includes a temperature detecting unit that detects a temperature of a compressor lubricating oil stored in a tank;
A pressure detecting means for detecting the pressure of the lubricating oil, a data storage unit for preliminarily storing data relating to the temperature and pressure of the lubricating oil and the amount of refrigerant mixed into the lubricating oil, A mixed refrigerant amount calculation unit for calculating the mixed refrigerant amount based on the temperature and the pressure and the related data stored in the data storage unit; a pressure reducing unit for reducing the pressure of the lubricating oil (J) in the tank; The amount of mixed refrigerant calculated by the section is compared with a preset threshold value, and if the threshold value is exceeded, a signal is output to the pressure reducing means to reduce the pressure of the lubricating oil in the tank, thereby reducing the amount of mixed oil. A mixed refrigerant amount adjusting section for setting the refrigerant amount to a threshold value or less.

[0008]

According to the configuration of the first aspect of the present invention, the temperature and pressure of the lubricating oil in the tank are detected, and based on the detected temperature and pressure and the related data stored in the data storage unit,
The mixed refrigerant amount calculation unit calculates the mixed refrigerant amount. The mixed refrigerant amount adjustment unit evaporates the refrigerant by heating the lubricating oil in the tank by the heating means when the calculated mixed refrigerant amount exceeds the preset threshold value, and reduces the mixed refrigerant amount. Set it below the threshold.

When the heating means comprises an electric heater, the responsiveness is good, and the lubricating oil can be quickly adjusted to an appropriate viscosity. Furthermore, when the heating means uses the discharge gas of the compressor as a heat source, energy saving can be achieved.
According to the configuration of the invention according to claim 4, the mixed refrigerant amount adjusting unit reduces the pressure in the tank by the pressure reducing unit,
The refrigerant is evaporated, and the amount of the mixed refrigerant is set to a threshold value or less.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a schematic configuration diagram of a lubricating oil adjusting device for a refrigerator according to one embodiment of the present invention. Referring to FIG. 1, a tank containing a lubricating oil J for lubricating and sealing a turbo compressor (not shown) is shown. A pump 3 for pumping lubricating oil to a turbo compressor via a supply line 2 and an electric heater 4 as a heating means for heating the lubricating oil J are provided at a lower portion of the tank 1. The lubricating oil J from the turbo compressor
Return line 5 is connected. The lubricating oil adjusting device for a refrigerator includes a pressure sensor 6 disposed in the tank 1 for detecting a pressure in the tank 1 and a lubricating oil J in the tank 1. A temperature sensor 7 for detecting the temperature of the oil, the electric heater 4, and the electric heater 4 which is disposed outside the tank 1 and turns on and off the electric heater 4 based on the detected temperature, pressure and the like of the lubricating oil J. And a control unit C for causing the AL to display an alarm.

The control unit C stores data (see FIG. 2) showing the relationship between the temperature T and pressure P of the lubricating oil J and the amount R (%) of refrigerant mixed in the lubricating oil J. In FIG. Data, a broken line indicates the data of R11), a temperature T and a pressure P of the lubricating oil J detected by the pressure sensor 6 and the temperature sensor 7, and data. A mixed refrigerant amount calculation unit 9 that calculates the mixed refrigerant amount based on the relation data stored in the storage unit 8
A mixed refrigerant amount adjusting unit 10 that adjusts the mixed refrigerant amount R based on the mixed refrigerant amount R calculated by the mixed refrigerant amount calculating unit 9 so as to be equal to or less than a threshold value R1; A timer 11 for operating the mixed refrigerant amount calculating unit 9 and the mixed refrigerant amount adjusting unit 10 every 3 minutes).

The mixed refrigerant amount adjusting unit 10 compares the mixed refrigerant amount R calculated by the mixed refrigerant amount calculating unit 9 with a predetermined threshold value R1 or R2 (R1> R2).
a, determining whether or not the mixed refrigerant amount R exceeds the threshold value R1 or R2, and if it exceeds, determining unit 10b that issues a predetermined signal, and receiving a signal from the determining unit 10b, An output unit 10c that outputs a signal for causing the electric heater 4 to heat the lubricating oil J in the tank 1 or a signal for stopping the compressor by displaying "excessive penetration" on the alarm display unit AL.
And

Next, the operation of the control section C will be described with reference to the flowchart of FIG. With the start of the turbo compressor, the timer 1 is started (step s1), and the elapse of a predetermined time t1 is waited (step s2). This is to wait for each state quantity to stabilize. After a lapse of a predetermined time t1, the temperature T and the pressure P of the lubricating oil J in the tank 1 are detected by the temperature sensor 7 and the pressure sensor 6.
Is input (step s3), and the mixed refrigerant amount calculation unit 9 calculates the mixed refrigerant amount R based on the temperature T, the pressure P, and the related data stored in the data storage unit 8 (step s4). Then, the mixed refrigerant amount R is compared with a preset threshold value R1 (step s5). If the mixed refrigerant amount R is equal to or more than the threshold value R1, "excessive penetration" is performed.
(Step s6), the turbo compressor is stopped (step s7). When the mixed refrigerant amount R does not exceed the threshold value R1, the mixed refrigerant amount R is compared with a preset threshold value R2 (step s).
8). If the mixed refrigerant amount R does not exceed the threshold value R2, the electric heater 4 is turned off (step s9).
Returning to step s1, if it has exceeded, the electric heater 4 is turned on to heat the lubricating oil (step s10), and waited until the elapsed time from the start reaches t2 (step s1).
1) Then, the process returns to step s1.

According to this embodiment, based on the temperature T, pressure P, etc. of the lubricating oil J, which can be accurately detected,
Since the mixed refrigerant amount R is obtained, an accurate mixed refrigerant amount R can be obtained. Then, while accurately grasping the mixed refrigerant amount R and adjusting the mixed refrigerant amount R to be equal to or less than the threshold value R2, the viscosity of the lubricating oil J can be maintained at an optimum. Therefore, the compressor does not suffer from poor lubrication, poor sealing, and the like, and there is no reduction in the performance of the refrigerator, so that the reliability of the refrigerator can be improved.

Further, since the electric heater 4 is used as the heating means, the refrigerant in the lubricating oil J can be heated and evaporated with good responsiveness, and the viscosity of the lubricating oil J can be quickly adjusted. FIG. 4 is a schematic view showing another embodiment of the present invention. Referring to FIG. 4, this embodiment differs from the embodiment of FIG. A discharge gas pipe 12 is provided as a heating means, which is connected to the condenser 13 in a state of passing through, and the lubricating oil J in the tank 1 is heated and evaporated using the heat of the discharge gas EG. The discharge gas line 12 is provided in the tank 1
It has a heat exchange portion 12a. An electromagnetic valve 14 that opens and closes the discharge gas pipe 12 is provided in the middle of the discharge gas pipe 12 outside the tank 1. If the mixed refrigerant amount R exceeds the threshold value R2, the solenoid valve 14 is opened to heat the lubricating oil J by the discharge gas EG, and if not, the solenoid valve 14 is closed to perform no heating. Generally, while the temperature of the lubricating oil J in the tank 1 is 40 to 60 ° C., the temperature of the discharge gas EG is about 100 ° C.,
It can be sufficiently heated by the discharge gas EG.

According to this embodiment, in addition to having the same operation and effect as the embodiment of FIG. 1, there is no external heat input, so that the efficiency of the refrigerator does not decrease, and therefore energy saving can be achieved. Can be. Further, since the heating is performed by the discharge gas EG, the load on the condenser 13 can be reduced. Note that the present invention is not limited to the above embodiments, and a pressure reducing pipe 15 as a pressure reducing means for reducing the pressure in the tank 1 can be used instead of the heating means (see FIG. 5). The pressure reducing pipe 15 communicates the inside of the tank 1 with the suction side IS of the impeller I. An electromagnetic valve 16 that opens and closes the pressure reducing pipe 15 is provided in the middle of the pressure reducing pipe 15. In this case, the mixed refrigerant amount adjustment unit 10 compares the mixed refrigerant amount R calculated by the mixed refrigerant amount calculation unit 9 with a preset threshold value R2. By opening the valve 16 to reduce the pressure of the lubricating oil J in the tank 1, the refrigerant is evaporated, and the amount R of mixed refrigerant is set to the threshold value R1 or less. This embodiment also has the same operation and effect as the embodiment of FIG.

The present invention is not limited to the above embodiments, and various changes can be made without changing the gist of the present invention.

[0018]

As described above, according to the first aspect of the present invention, the amount of mixed refrigerant is obtained based on the temperature, pressure, etc. of the lubricating oil with high detection accuracy. Can be Then, while the amount of the mixed refrigerant is accurately grasped and adjusted so as to be equal to or less than the threshold value, the viscosity of the lubricating oil can be maintained at the optimum. Therefore, the compressor does not suffer from poor lubrication, poor sealing, and the like, and there is no reduction in the performance of the refrigerator, so that the reliability of the refrigerator can be improved.

When the heating means comprises an electric heater, the responsiveness is good, so that the lubricating oil can be quickly adjusted to the optimum viscosity. Furthermore, when the heating means uses the discharge gas of the compressor as a heat source, energy saving can be achieved. According to the fourth aspect of the present invention, the pressure in the tank is reduced by the pressure reducing means, thereby evaporating the refrigerant to make the amount of the mixed refrigerant equal to or less than the threshold value, and has the same effect as the first aspect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an apparatus for adjusting lubricating oil for a refrigerator as one embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the temperature and pressure of lubricating oil and the amount of refrigerant mixed into lubricating oil.

FIG. 3 is a flowchart showing a control flow.

FIG. 4 is a schematic view of a lubricating oil adjusting device for a refrigerator as another embodiment of the present invention.

FIG. 5 is a schematic view of an apparatus for adjusting lubricating oil for a refrigerator as still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank J Lubricating oil 4 Electric heater (heating means) 6 Pressure sensor (pressure detecting means) 7 Temperature sensor (temperature detecting means) 8 Data storage part 9 Mixed refrigerant amount calculation part 10 Mixed refrigerant amount adjustment part 12 Discharge gas line ( Heating means) 15 Decompression line (Decompression means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04C 29/02

Claims (4)

(57) [Claims] A temperature detecting means for detecting a temperature of a lubricating oil for a compressor stored in a tank; a pressure detecting means for detecting a pressure of the lubricating oil; (6)
A data storage unit (8) for storing in advance data relating to the temperature and pressure of the lubricating oil (J) and the amount (R) of refrigerant mixed in the lubricating oil (J); A mixed refrigerant amount calculation unit (9) for calculating the mixed refrigerant amount (R) based on the temperature and pressure of (J) and the related data stored in the data storage means; J), the amount of mixed refrigerant (R) calculated by the mixed refrigerant amount calculator (9) is compared with a preset threshold value (R1), and the threshold value (R1 ), A signal is output to the heating means (4) to heat the lubricating oil (J) in the tank (1) so that the mixed refrigerant amount (R) is equal to or less than the threshold value (R1). A lubricating oil adjusting device for a refrigerator, comprising a mixed refrigerant amount adjusting section (10). 2. An apparatus for adjusting lubricating oil for a refrigerator according to claim 1, wherein said heating means comprises an electric heater. 3. The compressor according to claim 1, wherein said heating means is provided with a discharge gas (E
The lubricating oil adjusting device for a refrigerator according to claim 1, wherein G) is used as a heat source. 4. A temperature detecting means (7) for detecting a temperature of a lubricating oil (J) for a compressor stored in a tank (1), and a pressure detecting means for detecting a pressure of the lubricating oil (J). (6)
A data storage unit (8) for storing in advance data relating to the temperature and pressure of the lubricating oil (J) and the amount (R) of refrigerant mixed in the lubricating oil (J); A mixed refrigerant amount calculation unit (9) for calculating the mixed refrigerant amount (R) based on the temperature and pressure of (J) and the related data stored in the data storage means; Decompression means (1) for decompressing J)
5) and comparing the mixed refrigerant amount (R) calculated by the mixed refrigerant amount calculation unit (9) with a preset threshold value (R1). Decompression means (15)
And the pressure of the lubricating oil (J) in the tank (1) is reduced to reduce the mixed refrigerant amount (R) to a threshold value (R1).
An apparatus for adjusting lubricating oil for a refrigerator, comprising: a mixed refrigerant amount adjusting section (10) to be described below.