JPH0765574B2 - Refrigeration system using scroll compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a refrigeration system using a scroll compressor.

(Prior Art) Conventionally, a scroll type compressor incorporated in a refrigerating apparatus is disclosed in, for example, Japanese Patent Laid-Open No. 63-167084 and, as shown in FIG. 4, the central portion of the end plates (M) (N). From the to the outer circumference, fixed and movable scrolls (F) and (O) are provided, in which spiral bodies (B) and (C) are projected, and a drive shaft (K) and a cowta weight (W) integrated at its end, The movable scroll (O) is fixed to a fixed scroll (F) through a swing link (S) fitted to a projecting drive pin (D).
The refrigerant gas sucked from the suction port (L) on the outer circumference side of the spiral is compressed in the compression chamber (A) partitioned between the spiral bodies (B) and (C), and the discharge port (H) on the center side of the spiral is rotated. ).

The movable scroll (O) is a thrust bearing (P).
Placed on the frame (X) via the
A predetermined gap is secured between the end faces of (C) and the end plates (X) and (Y) in order to absorb processing errors, deformation of members, and the like. In addition, the lower surface (Q) of the swing link (S) is brought to the top surface (U) of the counterweight (W) by the lower collar portion (E) of the bearing tube (G) fitted over the drive pin (D). The limit pin (R) protruding from the counterweight (W) is loosely fitted to the drive pin (D) by being pivotally mounted in a cantilevered manner so as to float with respect to it, and a restriction hole (Z) provided on the other side. ) Is allowed to swing over a certain range, and when an abnormally high pressure is generated in the compression chamber (A) due to liquid compression at startup, a gap is created between the wall surfaces of the spiral bodies (B) and (C). It is made empty so that the abnormally high pressure can escape to the suction port (L) side.

(Problems to be solved by the invention) By the way, in the above compressor, a gap formed between the end faces of the spiral body (B) (C) and the end plates (M) (N) or a fitting portion of each member. As a result, the orbiting scroll (O) can tilt on the thrust bearing (P), but during normal operation, it overcomes this and the centrifugal force (fm) acting on the orbiting scroll (O) and the compression chamber (A). The wall surfaces of the spiral bodies (B) and (C) are in close contact with each other by the horizontal component (fr) of the force based on the internal pressure at the end plate (N) and the axial component (fn) of the force based on the internal pressure. The back surface of () is pressed by the thrust bearing (P), and the parallelism of the movable scroll (O) is maintained.

However, for example, as a prominent example, in order to remove the frost adhering to the heat exchanger that was acting as an evaporator in the refrigeration system in which this compressor is incorporated, the refrigerant flow path is reversed to the heat exchanger with frost adhering. When performing a defrost operation in which high-pressure discharge gas is passed, the discharge port (H)
The high pressure on the side decreases, and the low pressure on the suction port (L) side also decreases due to the decrease in the high pressure. , The internal pressure of the compression chamber (A) decreases, the components (fr, fn) become small, and the radial contact force for closely contacting the spiral bodies (B) and (C) and the end plate (N) are The pressing force in the thrust direction pressing the thrust bearing (P) becomes weak.

Therefore, the orbiting scroll (O) becomes unstable, the spiral bodies (B) and (C) are separated from each other as shown in FIG. When the movable scroll (O) is tilted, the movable scroll (O) is tilted.
Since the spiral bodies (B) and (C) are moved in a mortar shape, the spiral bodies (B) and (C) are separated from each other or re-contact with each other by shock, and an abnormal interference sound is generated. However, problems such as a decrease in the reliability of the will occur.

The present invention has been made in view of the above problems, and an object of the present invention is to perform an operation under a low pressure condition, and when the movable scroll is likely to tilt, an impact generated between the spiral bodies. A refrigerating apparatus using a scroll type compressor that can alleviate the physical interference and prevent the generation of abnormal noise.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an end plate (3a).
A spiral body (3b) (4b) from the center to the outer periphery of (4a)
The scroll is provided with fixed and movable scrolls (3) and (4) protruding from the inside of the closed casing (1), and the low pressure gas sucked from the suction port (13) on the outer side of the spiral is supplied to the scroll (3b) (4b).
In a refrigeration system that uses a scroll compressor that compresses in a compression chamber that is partitioned between and discharges high-pressure gas from the discharge port (14) on the center of the spiral, the suction gas path (2
The injection passage (24) for the oil or liquid refrigerant in the gas discharged to the outside of the closed casing (1) is opened in 5), and the discharge side high pressure or the suction side low pressure of the scroll compressor is opened. And a pressure detecting means (26) for detecting, and the injection path (24) when the detected value of the detecting means (26) exceeds a set value.
And an opening / closing means (27) which is opened when the detected value falls below a set value.

(Operation) When the detection value of the detection means (26) is lower than the set value when the operation is performed under a low pressure condition, that is, when the tilting phenomenon occurs in the movable scroll (4). Is
The opening / closing means (27) is opened, and the oil or liquid refrigerant discharged from the injection passage (24) to the outside of the closed casing (1) is injected into the compression chamber, and the spiral bodies (3b) (4b). ), An oil film or liquid film is formed between them, and this oil film or the like acts as a cushioning material, and shocking interference of the scrolls (3b) (4b) due to tilting of the movable scroll (4) is mitigated The generation of sound is reduced. At this time, since the oil or liquid refrigerant injected into the compression chamber is once discharged to the outside of the closed casing, the oil or liquid refrigerant has a relatively low temperature, and the intake gas heating is small, so that the compressor There is no reduction in efficiency.

(Example) FIG. 2 shows a scroll type compressor (10
0) shows a fixed scroll (3) in which a spiral body (3b) is projectingly provided on a disk-shaped end plate (3a) through a frame (2) in the upper inner part of the closed casing (1). Similarly, a movable scroll (4) having a scroll (4b) projecting from the end plate (4a) is vertically paired in a meshed state, and a drive shaft (5) is provided on the inner lower side of the casing (1). ) Is provided.

Each of the spiral bodies (3b) (4b) is provided with each of the end plates (3a) (4a).
The spiral body (3b) (4b) is formed from the central part to the outer peripheral part of the spiral body (3b) (4b) in conformity with a predetermined involute shape.
At the protruding tip side of b), the end plates (3a) (4
Tip seal (3) that fills the gap formed with a)
c) (4c) is fitted.

The fixed scroll (3) is fixedly supported on the upper mounting surface of the frame (2) via a fixing bolt (B).
On the other hand, the movable scroll (4) is rotatably supported via a thrust bearing (2a) provided on the upper part of the frame (2).

Then, a counterweight (7) integrally provided on the upper end of the drive shaft (5), a swing link (8) driven by the counterweight (7), and an Oldham ring (9) constituting a rotation preventing mechanism. ) And the orbiting scroll (4) is revolvingly driven with respect to the fixed scroll (3), and two-system compression chambers (11) (12) formed between the respective scrolls (3b) (4b). The refrigerant is compressed by.

In the figure, (13) is an intake port provided on the outer peripheral side of each of the scrolls (3b) and (4b), and (14) is the fixed scroll (3).
A discharge port opened in the center of the discharge port (15) is a check valve arranged in the discharge port (14).

FIG. 1 shows a refrigerating apparatus using the compressor (100) described above, and between the discharge pipe (16) and the suction pipe (17) connected to the casing (1) of the compressor (100). A heat exchanger (20) on the use side used for indoor air-conditioning, etc. through a four-way switching valve (19), an expansion mechanism (21a) for cooling, and a liquid receiver (3
0), the expansion mechanism for heating (21b), and the heat source side heat exchanger (22) installed outdoors. Also, the discharge pipe (1
An oil separator (40) is interposed in the high-pressure gas path (18) between the 6) and the four-way switching valve (19). In the figure, (21c)
Is a check valve that bypasses the cooling expansion mechanism (21a) when heating,
(21d) is a check valve for bypassing the heating expansion mechanism (21b) during cooling.

Then, during heating, the discharge gas is circulated in the path indicated by the solid line arrow in the figure so that the utilization side heat exchanger (20) functions as a condenser and the heat source side heat exchanger (22) functions as an evaporator. Heat source side heat exchanger (22) during cooling or during the above-mentioned heating
When the frost forms and the defrost operation is performed, the four-way switching valve (19) is switched to circulate the discharge gas in the reverse path indicated by the dotted arrow in the figure, and the heat source side heat exchanger ( 22) acts as a condenser, and the utilization side heat exchanger (20) acts as an evaporator. In this case, during the defrosting operation, high-pressure discharge gas is supplied to the frosted heat source side heat exchanger (22), so the pressure of the discharge gas decreases, and the low-pressure suction gas pressure is dragged by this. Will also be lowered.

Thus, in the above structure, the inlet side of the injection channel (24) is connected to the bottom of the oil separator (40), and the outlet side of the injection channel (24) is clearly shown in FIG. , Casing (1) of the compressor (100) through a joint pipe (24a)
To the compression chambers (11) and (12) from the suction pipe (17) by an L-shaped internal pipe (24b), specifically, the suction port (13). )
Corresponding to the above, the suction passage (25a) formed in the frame (2) is directed upward and opened, and the gas discharged to the outside of the casing (1) is separated by the oil separator (40). Make sure that the separated oil is actively included in the inhaled gas.

Further, in order to discriminate between normal operation and operation under low pressure conditions such as defrosting operation, as shown in FIG. 1, pressure detecting means (26) for detecting a high pressure in the discharge gas path (18). ) Through. In most cases, if the high pressure decreases, the low pressure on the suction side also decreases due to the low pressure. Therefore, the low pressure may be detected instead of the high pressure detection.

Further, when a predetermined pressure is secured and tilting is not a problem as in normal operation, the detection value of the detection means (26) exceeds the set value in order to prevent an increase in the amount of oil rise due to oil injection. In some cases, an opening / closing means (27) is provided that closes the injection path (24) and opens the injection path (24) when the detected value falls below a set value. The opening / closing means (27) is composed of a solenoid valve or the like, and is opened / closed via a controller (28).

Thus, when the discharge gas pressure becomes equal to or lower than a predetermined set value, such as when performing a defrost operation, the injection path (2
4) is opened, oil is injected into the intake gas from the oil separator (40), an oil film is formed at the contact portion of each of the spiral bodies (3b), (4b), and this oil film functions as a buffer material. The shocking interference between the spiral bodies (3b) and (4b) can be alleviated.

In the above embodiments, oil injection was used, but in addition, as shown in FIG. 3, the liquid refrigerant in the gas discharged to the outside of the casing (1) is stored in the liquid receiver (30), and this storage is performed. The high-pressure liquid refrigerant thus generated may be injected into the intake gas path (25) via the injection path (24). In this case, the liquid refrigerant forms a liquid film between the spiral bodies (3b) (4b). It will be made and act as a cushioning material. Even in this case, when the predetermined pressure is secured and tilting does not pose a problem as in normal operation, the detection value of the detection means (26) is set in order to prevent liquid compression due to injection of liquid refrigerant. An opening / closing means (27) is provided which closes the injection path (24) when the value exceeds the value and opens the injection path (24) when the detected value falls below the set value. The opening / closing means (27) is composed of a solenoid valve or the like, and is opened / closed via a controller (28).

In the embodiment of FIG. 3, the inlet (24c) is provided near the suction port (13) on the end plate (3a) of the fixed scroll (3).
The inner pipe (24a ') between the inlet (24c) and the joint pipe (24a') attached to the top of the casing (1).
It is connected via b '). In addition, the injection channel (2
As in FIG. 2, 4) may be opened to the suction passage (25a) or the suction pipe (17). In this case, the suction gas is in a wet state, and the above-mentioned each indirectly. A liquid film will be formed between the spiral bodies (3b) and (4b).

(Effects of the Invention) As described above, in the present invention, the intake gas passage (25)
The opening of the injection passage (24) for the oil or liquid refrigerant in the gas discharged to the outside of the closed casing (1), and the pressure for detecting the high pressure on the discharge side or the low pressure on the suction side of the scroll compressor. Since the detection means (26) and the opening / closing means (27) which closes the injection passage (24) when the detection value of the detection means (26) exceeds the set value and opens when the detection value falls below the set value When the movable scroll (4) is operated under a low pressure condition in which a tilting phenomenon occurs, the gas in the gas once discharged to the outside of the closed casing from the injection passage (24) opened by the opening / closing means. A relatively low temperature oil or liquid refrigerant is injected into the intake gas passage, and the injected oil or liquid refrigerant can form an oil film or a liquid film between the spiral bodies (3b) and (4b). Each spiral body (3b) (4
The shock interference of b) can be mitigated, the occurrence of abnormal noise, etc. can be reduced, and because the injected oil or liquid refrigerant is at a relatively low temperature, the intake gas heating is small and the compressor efficiency is reduced. In normal operation where a predetermined pressure is secured and tilting is not a problem, the injection passage (24) is closed by the opening / closing means, and oil or liquid refrigerant is injected into the intake gas passage. As a result, there is no increase in the amount of oil rise or liquid compression.

[Brief description of drawings]

1 is a piping diagram showing a refrigerating apparatus using a scroll compressor according to the present invention, FIG. 2 is a partially omitted vertical sectional view showing the entire structure of a scroll compressor used in the refrigerating apparatus, FIG. FIG. 3 is a drawing of another embodiment, FIG. 4 is a sectional view of a conventional example, and FIGS. 5 (a) and 5 (b) are explanatory views of the problem. (3) …… Fixed scroll (4) …… Movable scroll (3a) (4a) …… End plate (3b) (4b) …… Swirl body (13) …… Suction port (14) …… Discharge port (24) … Injection path (25) …… Intake gas path (26) …… Pressure detection means (27) …… Opening / closing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Izumiya, 3-12, Chikko Shinmachi, Sakai City, Osaka Prefecture Daikin Industries, Ltd.

Claims (1)

[Claims] 1. A fixed and movable scroll (3) (4) having a scroll (3b) (4b) projecting from a central portion to an outer peripheral portion of an end plate (3a) (4a) is provided in a hermetic casing (1). , Low-pressure gas sucked from the suction port (13) on the outer side of the spiral is compressed in a compression chamber partitioned between the spiral bodies (3b) and (4b),
In a refrigerating apparatus using a scroll compressor configured to discharge high-pressure gas from a discharge port (14) on the center of a spiral, a closed casing (1) is provided in a suction gas path (25).
A pressure detection means (26) for opening an injection passage (24) for oil or liquid refrigerant in the gas discharged to the outside, and for detecting a high pressure on the discharge side or a low pressure on the suction side of the scroll compressor; A scroll provided with an opening / closing means (27) which closes the injection passage (24) when the detection value of the detection means (26) exceeds a set value and opens when the detection value falls below the set value. Refrigerator using a compact compressor.