JPH0240466A - Refrigerator lubricating oil adjustment device - Google Patents

Abstract

PURPOSE:To always properly maintain the viscosity of lubricating oil by calculating a cubage signal for showing the cubage of the lubricating oil of a tank, the specific gravity thereof and a mixing refrigerant quantity from a weight signal to transmit a signal to a heating means. CONSTITUTION:Liquid level of lubricating oil 2 of a tank 1 is input in an arithmetic circuit 14 as a cubage signal from a level detector 10 and a converter 13 and further the weight thereof is input therein as a weight signal from a weight detector 11 and a detecting circuit 12. The specific gravity thereof is calculated in the arithmetic circuit 14 by both the signals while a mixing a refrigerant quantity from the set signal of the setter 15 can be calculated, the signal thereof is transmitted to a control device 9 when it exceeds the prescribed value, electric heaters 8a, 8b are turned on to heat the lubricating oil 2 in which refrigerant is mixed and oil temperature is heightened to evaporate and separate the refrigerant. Therefore at the time of operation a refrigerant quantity mixed and penetrated in the lubricating oil used in a refrigerator is detected and properly eliminated to always normally maintain and control the viscosity thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an apparatus for adjusting the viscosity, etc. of lubricating oil for refrigerators used in internal air conditioning equipment of various buildings and the like.

(Prior Art) Many refrigerators are used in air conditioning equipment in various plants such as power plants and buildings such as buildings, and a typical example is a turbo refrigerator. This consists of a turbo compressor, a driving motor, a heat exchanger (evaporator, condenser), a transmission device, a bleed air recovery device, a lubrication device, etc. Regarding this internal lubrication device, it is necessary to optimally manage the viscosity of the lubricating oil in order to maintain good lubrication of the moving parts of the compressor and good sealing effect of the compression grooves. However, as the refrigerating machine operates, refrigerant is mixed into the lubricating oil, stirred, and dissolved, and as a result, the viscosity of the lubricating oil gradually decreases, which adversely affects the operation of the compressor and reduces the capacity of the refrigerating machine. When this condition progresses, the protection device stops the refrigerator, making air conditioning impossible. Conventionally, the temperature of the lubricating oil was controlled to evaporate and separate the refrigerant that had mixed into the lubricating oil and removed it. That is, as shown in the schematic configuration diagram in Figure 3,
Lubricating oil 2 stored in a tank 1 is pumped by a pump 3 through a supply line 4 to a turbo compressor (not shown). The lubricating oil 2 that has passed through the turbo compressor is mixed with the refrigerant and dissolved therein, reducing its viscosity and flowing back into the tank 1 through the return line 5. Since this lubricating oil 2 is circulated,
The viscosity of the lubricating oil 2 in the tank 1 gradually decreases, and both the lubrication and sealing functions decrease, resulting in a decrease in the compression capacity of the turbo compressor and, ultimately, the lubrication and refrigeration capacity of the refrigerator.

As a countermeasure for this, a temperature detector 6 and a heater 7 are installed inside the tank 1 to detect the temperature of the lubricating oil 2, and when the lubricating oil temperature falls below the lower limit of the set value, the heater 7 is activated.
heat up. The refrigerant mixed and dissolved into the lubricating oil 2 is eluted and evaporated as the temperature rises and is separated from the lubricating oil 2, so that the viscosity of the lubricating oil 2 returns to normal and the function of the refrigerator is restored.

When the lubricating oil temperature reaches the upper limit of the set value, heating by the heater 7 is stopped in response to a signal from the temperature detector 6. As described above, the viscosity of the lubricating oil 2 is maintained in a normal state by controlling the oil temperature in the tank 1. Note that the refrigerant gas separated from the lubricating oil 2 is removed and recovered by a recovery device (not shown).

(Problem to be Solved by the Invention) In the method for maintaining lubricating oil viscosity by controlling the temperature of lubricating oil 2 in tank 1, separation of the refrigerant from lubricating oil 2 is not directly related to m of the refrigerant mixed in lubricating oil 2. Since this is carried out, there is a drawback that not only the amount of refrigerant separated or the amount mixed into the lubricating oil 2 but also the viscosity is unclear. Therefore, even if the lubricating oil temperature matches the set value, it is unclear whether the viscosity of lubricating oil 2 and the amount of refrigerant mixed in at this point are appropriate, and the influence on the refrigerator cannot be directly determined. The problem was that it could not be detected and treated.

The present invention has been made in view of the above, and its purpose is to calculate the refrigerant m mixed and dissolved in the lubricating oil from the specific gravity of the lubricating oil in the tank, and to calculate the amount of refrigerant m in the tank according to the result. To provide an adjustment device for lubricating oil for freezing, which controls the temperature of the lubricating oil to increase and evaporate and remove the refrigerant, and maintains the viscosity of the lubricating oil at an appropriate level at all times to fully exhibit the functions of a refrigerator. It is in.

[Structure of the Invention] (Means for Solving the Problems) A lubricating oil heating means is provided at the lower part of the tank storing the lubricating oil, a lubricating oil liquid level detecting means is provided at the upper part of the tank, and a lubricating oil is provided at the outer lower part of the tank. A converter for calculating the volume of the lubricating oil in the tank from the liquid level signal of the liquid level detecting means, a volume signal from the converter and a signal from the weight measuring means; a calculation means that calculates the specific gravity of the lubricating oil in the tank and the amount of mixed refrigerant and issues a signal to the heating means; Equipped with a setting device that outputs to

(Function) The calculation means calculates the specific gravity of the lubricating oil in the tank from the weight of the lubricating oil in the tank by the weight measuring means and the volume of the lubricating oil in the tank by the liquid level detection means and the converter, and The amount of mixed refrigerant in the lubricating oil in the tank is calculated based on the signal from the setting device that has preset the specific gravity and amount of mixed refrigerant corresponding to the appropriate viscosity of the lubricating oil, and if this exceeds the specified value, the heating means The temperature of the lubricating oil is increased to evaporate and remove the refrigerant to maintain the appropriate viscosity of the lubricating oil to protect the refrigerator and prevent a drop in performance.

(Example) An embodiment of the present invention will be described with reference to the drawings.

Note that the same components as those in the prior art described above are given the same reference numerals and detailed explanations are omitted.

FIG. 1 is a schematic configuration diagram, and the present invention includes a pump 3 for pressurizing lubricating oil 2, which has a supply line 4 connected to the lower part of a tank 1 containing lubricating oil 2 for lubricating and sealing a turbo compressor (not shown); Two sets of electric heaters 8a serving as heating means for lubricating oil 2
, ab is installed, and its control device 9 is provided. tank 1
At the top of the is a return line 5 for lubricating oil 2 from the turbo compressor.
An ultrasonic level detector 10, which is a means for detecting the liquid level of the lubricating oil 2 inside the tank 1, is arranged. In addition, a weight detector 11, which is a means for measuring the weight of the lubricating oil 2 in the tank 1, is installed at the outer lower part of the tank 1. A detection circuit 12 is provided which calculates the weight of the lubricating oil 2 in the tank 1 from this output signal.

Furthermore, a converter 13 calculates the volume of the lubricating oil 2 in the tank 1 from the liquid level signal from the level detector 10, and a weight signal from the weight detection circuit 11 and the volume signal from the tank 1.
Calculate the amount of mixed refrigerant from the specific gravity of inner lubricating oil 2, and
It is comprised of a setting device 15 for presetting the specific gravity and allowable amount of mixed refrigerant corresponding to the range of appropriate viscosity, and an arithmetic circuit 14 which is a calculation means for issuing a signal to the heating means based on a signal from the setting device 15.

FIG. 2 is a detailed circuit diagram of the heating means. Two sets of electric heaters 8a and 8b installed in the tank 1 are divided into two systems as a safety measure in case of disconnection, and two electromagnetic contacts in the control device 9 are installed in the tank 1. Power is connected and disconnected by main contacts 16a and 117a of devices 16 and 17. The electromagnetic contactors 16 and 17 are connected in series with contacts between the control power supplies P and N, which are closed in response to the refrigerant amount large signal H from the arithmetic circuit 14, together with the timer 18. time-limited contact 18
In addition, an auxiliary contact 16b of the electromagnetic contactor 16 is inserted into the timer 18.

Next, the effect of the above configuration will be explained. The lubricating oil 2 in the tank 1 is pumped by a pump 3 through a supply line 4 to a turbo compressor (not shown), where it performs the work of lubrication and sealing, and the refrigerant is mixed in and drawn into the return line 5. The water is then refluxed to tank 1. As a result, the viscosity and specific gravity of the d''n lubricating oil 2 in the tank 1 are reduced due to the mixing of the refrigerant, and therefore the volume per unit of mass is increased.

This decrease in viscosity immediately leads to a decrease in the ability of frozen seashore. At this time, in the tank 1, for example, if there is no change in weight, the volume will increase and the liquid level will rise, and if there is no change in the liquid level, that is, no change in volume, the weight will necessarily decrease.

This condition is constantly detected, and the liquid level is detected by level detector 1.
0 and the converter 13 as a volume signal, and the weight is inputted to the arithmetic circuit 14 as an ff1ffi signal by the weight detector 11 and the detection circuit 12. Based on these two signals, the arithmetic circuit 14 calculates the specific gravity, and the mixed refrigerant ■ is calculated from the setting signal from the setting device 15, and when this is more than the specified value, a signal is sent to the control device 9 to control the electric heaters 8a and 8b. lIs' that is energized and mixed with refrigerant
Heat the J lubricating oil 2 to raise the oil temperature and evaporate and separate the refrigerant. This evaporated and separated refrigerant gas is recovered by a recovery device (not shown). In other words, as shown in Figure 2, the control device @9
When the contact of the large refrigerant amount signal H closes, the main contact 16a and the auxiliary contact 16b of the electromagnetic contactor 16 are closed, the electric heater 8a is energized, and the timer 18 also starts operating. tank 1
Initially, the lubricating oil 2 in the interior is heated by a set of electric heaters 8a to evaporate the refrigerant, but even after the time set by the timer 18 has elapsed, the amount of mixed refrigerant does not decrease below the predetermined value, and the refrigerant amount large signal day still remains. If it is emitted, timer 18
When the time-limited contact 18a is closed, the electromagnetic contactor 17 is operated to energize the other set of electric heaters 8b, and thereafter the refrigerant is evaporated and separated by the two sets of electric heaters 8a and 8b.

If one of the electric heaters 8a is disconnected at this time, heating will not start when the electromagnetic contactor 16 is closed, but heating and evaporation work will start by the electric heater 8b after the timer 18 is activated after a time delay. be done. Further, when the electric heater 8b is disconnected, heating is performed only by the electric heater 8a from the beginning. Although the heating capacity is reduced in both cases, the evaporation and removal work of the refrigerant does not stop, and if the amount of mixed refrigerant is small, the removal effect is sufficient. Furthermore, when the refrigerant in the lubricating oil 2 is removed, the lubricating oil 2 is calculated by the calculation circuit 14.
Since the specific gravity and amount of refrigerant mixed in are within the setting range from the setting device 15 and the output signal to the control device 9 is stopped, the 21 yen magnetic contactor 16, 17 and the timer 18 are released and sent to the electric heaters 8a and 8b. The heating of the lubricating oil 2, that is, the evaporation of the refrigerant, is stopped. However, since the refrigerant in the lubricating oil 2 continues to evaporate for a while due to residual heat, the recovery device is constantly operated. In addition, in the above operation, the level detector 10 and the weight detector 11 constantly monitor the liquid level and weight of the lubricating oil 2 in the tank 1, so if the mixed cold 1 fl falls outside the setting range from the setting device 15, , evaporation of the refrigerant,
Since the removal work is automatically started and stopped, the lubricating oil 2 always contains less cold Is, maintains appropriate viscosity and good characteristics, and allows the turbo compressor to operate under optimal conditions. In addition, the heating means is provided with lubrication (not shown) 11
By providing a separate temperature adjustment device such as a temperature sensor (2), the electric heaters 8a and 8b can be disconnected from and connected to the power source as appropriate to maintain an appropriate temperature range for refrigerant evaporation.

[Effects of the Invention] According to the present invention, the extent of the refrigerant mixed into and dissolved in the lubricating oil used in the refrigerator during operation is detected, and this is appropriately removed to maintain and manage the viscosity normally. Therefore, there will be no adverse effects on the compressor such as poor lubrication or sealing caused by refrigerant contamination or viscosity reduction, and there will be no reduction in chiller performance or emergency stoppages, improving the operating efficiency and reliability of chillers and air conditioning equipment. It has the effect of improving

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram not showing an embodiment of the present invention, Fig. 2 is a detailed circuit diagram of a heating means of an embodiment, and Fig. 3 is a conventional f
, 1 is a schematic configuration diagram of a lubricating oil adjusting device. DESCRIPTION OF SYMBOLS 1...Tank, 8a, 8b...Electric heater, 10...Level detector, 12...Detection circuit, 14...Arithmetic circuit, 16.17...Magnetic contactor,

Claims (1)

[Claims] A pump for lubricating oil pressure with a supply line connected to the lower part of the tank storing lubricating oil for the compressor, and a return line for the lubricating oil from the compressor to the upper part, installed at the lower part of the tank. A lubricating oil heating means, a lubricating oil level detecting means disposed at the top of the tank, a lubricating oil weight measuring means disposed at the outer lower part of the tank, and a lubricating oil in the tank based on the liquid level signal from the liquid level detecting means. a converter for calculating the volume of the tank; and calculating means for calculating the specific gravity of the lubricating oil in the tank and the amount of refrigerant mixed in the tank from the volume signal from the converter and the weight signal from the weight measuring means, and issuing a signal to the heating means. A lubricating oil adjusting device for a refrigerator, comprising a setting device that presets specific gravity and mixed refrigerant amount corresponding to a range of appropriate viscosity of the lubricating oil and outputs this signal to the calculation means.