JPH0445360A - Refrigerator - Google Patents

Abstract

PURPOSE:To permit the refrigerating oil separated from an oil separator to be returned properly to a compressor in order to reduce a lowering in refrigerating performance by a method wherein the opening degree of a flow amount adjusting valve provided in an oil passage for returning the refrigerating oil separated from the separator to a compressor is controlled according to the time of the continued operation of the compressor after the start of its operation. CONSTITUTION:Voltage E1 is delivered from a device 18 for controlling a flow amount adjusting valve after the lapse of time (t) during which the discharged amount of refrigerating oil from a compressor 1 is small. By this voltage E1, the coil part 17a of a flow amount adjusting valve 17 is energized to make small the opening degree of the flow amount adjusting valve 17. Since the amount of the refrigerating oil being sent back into the compressor 1 through an oil passage 8 is reduced as the opening degree of the flow amount adjusting valve 17 is decreased and since the amount of the refrigerating oil discharged from the compressor 1 together with a gas refrigerant is also small, a predetermined amount of the refrigerating oil is retained in the compressor 1. Therefore, a full lubrication is effected, the amount of the gas refrigerant being sent back into the compressor 1 through the oil passage 8 becomes small and a lowering in the refrigerating performance of a refrigeration device is reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention separates refrigerant gas and refrigeration oil discharged from a compressor using an oil separator, and sends the separated refrigeration oil to the compressor via an oil path. This invention relates to an improvement in a refrigeration system that allows the refrigerating system to return to its normal state.

[Conventional technology]

FIG. 4 is a refrigerant circuit diagram showing a conventional refrigeration system disclosed in, for example, Japanese Utility Model Publication No. 56-5030, and FIG. 5 is a control circuit diagram of the refrigeration system shown in No. 4UA. In these figures, (1) is a compressor, (21 is an oil separator, (3) is a condenser, (4) is a liquid receiver, (5) is a liquid solenoid valve, (6) is an expansion valve, ( 7) is an evaporator, and a refrigeration cycle circuit is constructed by sequentially connecting these needle refrigerant pipes. 8 is an oil line that returns the refrigeration oil separated by the oil separator (2) to the compressor +11. , one end is connected to the oil separator (21) and the other end is connected to the refrigerant suction side of the compressor (1) (9).
is a high-pressure pressure switch, which is connected between the oil separator (2) and the condenser β) via a pressure take-off pipe. (
II) is a low-pressure pressure switch, and pressure extraction piping (II)
(lal is the electric motor of the compressor (1), (3a) is the blower that blows air to the condenser G), and (7a) is the evaporator. These blowers (3a) (7a)
, the electric motor (1a) is connected to a power source (14) via an a contact (13b) of an electromagnetic contactor. (+51 is the compressor (1) and the overcurrent relay that detects the flow of overcurrent, (13a) is the coil part of the electromagnetic contactor, <5a) is the coil part of the liquid solenoid valve (5) and the electromagnetic contactor Coil part (13a
) are both connected in parallel to the internal thermoswitch (
16), B contact (lla) of low pressure switch <11),
It is connected to the power source (14) through a series connection circuit of the B contact (9a) of the high pressure switch (9) and the B contact (1'5a) of the overcurrent relay (5).

Next, the operation will be explained. When the low pressure and internal temperature are high, the B contact (lla) of the low pressure switch (11) and the internal thermoswitch (16) are closed, and the coil part (13a) of the electromagnetic contactor and the liquid solenoid valve ( The coil part (5a) of 5) is energized, the liquid electromagnetic valve (5) opens, and the a contact (+3b) of the electromagnetic contactor closes. As a result, the electric motor (1a) of the compressor (1), the blower (3a) of the condenser 0), and the blower (7a) of the evaporator (2) are driven, and the compressor (1) also has an oil separator (2). The refrigerating machine oil separated in is returned through the oil passage 8, and the returned refrigerating machine oil provides lubrication and performs cooling operation.

When the internal thermoswitch (16) is turned OFF, the coil part (5a) of the liquid solenoid valve (9) is de-energized and the liquid solenoid valve (9) is de-energized.
(5) is closed and the excitation of the coil portion (13a) of the electromagnetic contactor is also eliminated, so the a contact (+3b) of the electromagnetic contactor is opened and the refrigeration system is stopped.

[Problem to be solved by the invention]

Conventional refrigeration equipment is configured to return the refrigeration oil separated by the oil separator (2) to the compressor (1) via the oil line (8), so when the compressor (1) is started, the evaporator oil is returned to the compressor (1). (The liquid refrigerant that has returned to the compressor (1) from the blade and the liquid refrigerant that has returned when the compressor (1) is stopped causes forcing when the compressor (1) is started and is discharged from the compressor (1). A large amount of refrigerating machine oil is discharged together with the gas refrigerant, and if the pipe diameter of the oil passage (&) is small, the relationship between the amount of refrigerating machine oil in the compressor (1) and the time after starting the compressor is shown in Figure 6. As shown by the solid line, the refrigerating machine oil in the compressor ( ) runs out within a predetermined time after the compressor is started. Therefore, in order to secure the refrigerating machine oil in the compressor (1), the above oil M@ [8] If the diameter of the piping is increased, the decrease in refrigerating machine oil in the compressor (1) will be alleviated, as shown by the broken line in Figure 6, but after a predetermined time after the compressor (1) has started, ] The discharged gas refrigerant is connected to the oil passage (8).
There was a problem that the refrigeration function was greatly deteriorated because the refrigeration function was returned to the suction side of the compressor (1) through the compressor (1).

This invention was made to solve the above-mentioned problems, and provides a refrigeration system in which the refrigeration oil separated by the oil separator can be properly returned to the compressor, and the refrigeration function is less degraded. The purpose is to obtain.

[Means to solve the problem]

The refrigeration system according to the present invention is provided with a flow rate adjustment valve in the oil path that returns the refrigeration oil separated by the separator to the compressor, and the opening degree of the flow rate adjustment valve is adjusted according to the continuous operation time of the compressor after startup. It was designed to be controlled.

[Effect]

In the refrigeration system according to the present invention, an appropriate amount of refrigeration oil is returned to the compressor through the oil passage, and the compressor is properly lubricated without significantly impairing the refrigeration function.

〔Example〕

FIG. 1 is a refrigerant circuit diagram of a refrigeration system showing an embodiment of the present invention, and FIG. 2 is a control circuit diagram of the refrigeration system shown in FIG. In these figures, the difference from Figures 4 and 5 is that a flow rate JAI regulating valve (17) is provided in the oil passage (8), the valve opening degree of which is adjusted by the voltage value applied to the coil part (17a). At the same time, the voltage E2 shown in FIG. 3 is output at time t from the start of the compressor when multiple refrigerating machine oils are discharged from the compressor (1) together with the waste refrigerant, and after the above time, the voltage E1 is output. A flow rate adjustment valve control device (18) is provided in parallel to the coil section (13a) of the electromagnetic contactor, and the voltages E1 and E2 are applied to the coil section (17a) of the flow rate adjustment valve (17).
), the opening degree of the flow adjustment valve (17) is controlled.

Next, the operation will be explained. When the coil part (13a) of the electromagnetic contactor is excited in the same way as the conventional one described above, the a contact (+3b) of the electromagnetic contactor is closed, the compressor (1) is started, and the compressor (1) A large amount of refrigerating machine oil is discharged together with the waste refrigerant. Then, the refrigerating machine oil is separated in the oil separator (21).On the other hand, at time t from the start of the compressor, multiple refrigerating machine oils are discharged from the compressor (1).
The flow rate regulating valve (17) is controlled by the voltage E1 output from the
) is excited, the valve opening of the flow rate adjustment valve (17) becomes A2 as shown in Fig. 3, the flow rate adjustment valve (17) opens wide, and the oil separator (2) A large amount of separated refrigerating machine oil is returned to the compressor fl) via an oil passage. As a result, a predetermined amount of refrigerating machine oil is secured within the compressor (1), and the interior of the compressor (1) is sufficiently lubricated.

Further, after the time when the amount of refrigerating machine oil discharged from the compressor (1) is small, the voltage E is output from the flow rate adjustment valve control device (18). The coil portion (17a> of the flow rate adjustment valve (17) is energized by this output voltage E1, and the valve opening of the flow rate adjustment valve (17) becomes A1 as shown in FIG. 3, and the valve opening becomes smaller. As the opening degree of the flow rate adjustment valve (17) becomes smaller, the compressor (
The amount of refrigerating machine oil returned to 1) will also decrease, but the amount of refrigerating machine oil returned to the compressor (
Since the amount of refrigerating machine oil discharged together with the gas refrigerant from the compressor (1) is small, the specified refrigerating machine oil is secured in the compressor (1), sufficient lubrication is performed, and the compressor (
1) The amount of discharged gas refrigerant returned is reduced, and the deterioration of the refrigeration function of the refrigeration system is reduced.

In addition, in the above embodiment, the flow rate adjustment valve control device (
18), the voltage E2 is output at time t from the start of the compressor, and the voltage E is output after that time. Thereafter, the voltage E may be output periodically, and the valve opening degree of the flow rate regulating valve (17) may be set to 0 for a predetermined period during which the voltage E1 is not output. In this case, the reduction in the refrigeration function of the refrigeration system is further reduced. Become.

〔Effect of the invention〕

As described above, according to the present invention, a flow rate regulating valve is provided in the oil path that returns the refrigerating machine oil separated by the oil separator to the compressor, and the miscarriage regulating valve is adjusted according to the continuous operation time from the start of the compressor. Since the valve opening degree is controlled, the refrigerating machine oil according to the discharge value of the refrigerating machine oil discharged from the compressor together with the gas refrigerant is returned to the compressor via the oil path, and the specified refrigerating machine oil is always ensured in the compressor. In addition, the return of the gas refrigerant through the oil path is reduced, the reduction in the refrigerating capacity of the refrigeration system is reduced, and the compressor is sufficiently lubricated.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a refrigerant circuit diagram of a refrigeration system showing an embodiment of the present invention, FIG. 2 is a control circuit diagram of the refrigeration system shown in FIG.
Figure 3 is a diagram showing the relationship between the valve opening and voltage of the flow rate regulating valve shown in Figure 1, Figure 4 is a refrigerant circuit diagram of a conventional refrigeration system, and Figure 5 is the refrigeration system shown in Figure 4. The control circuit diagram of the apparatus, FIG. 6, is a diagram showing the relationship between the refrigerating machine oil smear in the compressor and the time after the compressor is started. In the figure, (1) is a compressor, (2) is an oil separator, and (8)
(17) is a flow rate adjustment valve, (17a) is a coil portion of the flow rate adjustment valve, and (18) is a flow rate adjustment valve control device. In addition, in the figure, the same reference numerals indicate corresponding parts.

Claims (1)

[Claims] The refrigeration cycle circuit includes a compressor, an oil separator, a condenser, a throttling device, and an evaporator connected sequentially through refrigerant piping, and the refrigeration oil separated by the oil separator is compressed through the oil line. The compressor is returned to the machine, characterized in that a flow rate adjustment valve is provided in the oil path, and the valve opening degree of the flow rate adjustment valve is controlled in accordance with the continuous operation time of the compressor from the time of startup. refrigeration equipment.