JPS6410675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection device for a scroll compressor.

A scroll compressor consists of a combination of fixed and rotating whirlpool blades formed by an involute tooth profile, and the scroll compressor precesses while the inner and outer wall surfaces of the rotating whirlpool blades are in contact with the fixed whirlpool blade wall surfaces. The refrigerant gas is sucked and compressed. These scroll compressors 1 have a condenser 2,
A conduit is connected in series with the first pressure reducing mechanism 3, the gas-liquid separator 4, the second pressure reducing mechanism 5, the evaporator 6, etc. to form a refrigeration cycle, and has a connection opening to the gas section of the gas-liquid separator 4. 7 is connected to the chamber of the scroll compressor 1 after suction and confinement of the refrigerant gas through an on-off valve such as a solenoid valve 8, and the refrigerant gas is sucked in to increase the capacity. Generally, a heating device such as a heater is used as a means for increasing heating capacity, but increasing heating capacity by injection is more advantageous in terms of other equipment, energy saving, etc.

However, conventionally, the size of the refrigerant injection hole for so-called injection injection, which injects intermediate pressure gas generated in a gas-liquid separator into a chamber after refrigerant gas suction and confinement, is limited by the thickness of the swirl vane. Therefore, a small diameter one was installed in one suction confinement chamber. As a result, a sufficient passage area for injection cannot be obtained, resulting in a decrease in the amount of injection, resulting in the disadvantage that the compressor cannot fully utilize its capacity.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a scroll compressor whose capacity can be sufficiently increased by injection extraction.

In order to achieve the above-mentioned object, the present invention provides a fixed scroll with a plurality of blade winding angles from a state in which the ends of the blade windings of the fixed scroll and the orbiting scroll are closed to a state in which the cylinder internal pressure becomes equal to the injection exit pressure. Opening a circular hole or a continuous groove-shaped injection extension hole to increase the passage area and reduce passage resistance,
The structure is such that the refrigerant is sufficiently injected.

The opening position of the injection hole is at least one turn from the end of the scroll on the inside of the blade of the fixed scroll.
On the outside, it must be located at least 1.5 turns closer to the center and at a position that is at least at an impeller winding angle that does not cause the internal pressure of the suction gas confinement chamber to become higher than the injection pressure. In other words, the range of the blade winding angle (λ) in which the injection exit hole can be made is determined by the winding end angle (λl) of the blade, the blade winding angle (λi) at which the internal pressure of the suction gas confinement chamber becomes equal to the injection exit pressure. Then, the inner position of the blade of the fixed scroll is λi≦λ≦λl−2π and the outer position is λi−π≦λ≦λl−3π The involute tooth profile is based on the base circle 9 as shown in Figure 2.
A curve drawn by the end 11 of the thread 10 wound around the base circle 9, which curve is determined by the radius (R) and the angle (λ) of the base circle 9. The impeller winding angle (λi) at which the internal pressure of the suction gas confinement chamber becomes equal to the injection pressure is determined by the suction pressure, the end winding angle, the radius of gyration, and the radius of the base circle.

On the other hand, the injection amount is determined by the amount of gas generated in the gas-liquid separator 4 or the pressure difference between the injection pressure and the internal pressure of the suction gas confinement chamber. The former increases as the injection pressure is lowered, and the latter increases as the injection pressure increases, so they have contradictory characteristics. Generally, it is desirable to carry out injection at an intermediate pressure between the two.
For this purpose, it is necessary to reduce the pressure loss from the gas-liquid separator 4 to the injection hole as much as possible.

The present invention greatly increases the passage area by providing a plurality of injection holes of appropriate diameters throughout a certain angular range suitable for injection, and by reducing pressure loss, increases the amount of refrigerant gas to be injected. In addition, the diameter of the plurality of injection holes is limited to prevent gas leakage and improve performance.

Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in FIGS. 3 to 9.

FIG. 3 is a sectional view of the scroll compressor. The compressor section 12 includes a fixed spiral portion 13 fixed to a closed container 18, a rotating spiral portion 14 that engages with the fixed spiral portion, and a frame 15 that rotatably locks the rotating spiral portion 14. It is provided. Reference numeral 16 denotes a crankshaft, which is connected to the turning spiral portion 14 and supported by a bearing 17 fitted into the frame 15. The electric motor part is in a closed container 18
It consists of a fixed coil section 19 fixed to the crankshaft 16 and a rotating rotor section 20, which is fixed to the crankshaft 16. Reference numeral 21 denotes an oil reservoir, and the crankshaft 1 is inserted into the oil reservoir 21.
The lower end of the crankshaft 16 is immersed.
The bearing is configured to be supplied with oil by an oil supply mechanism installed in the lower part of the bearing. Reference numeral 22 denotes a refrigerant gas suction passage which is opened and connected to a passage 23 that communicates with the inside of the spiral groove of the fixed spiral portion 13 . Further, the other end of the suction passage 22 is connected to the evaporator 6 (FIG. 1). Reference numeral 24 denotes a refrigerant gas discharge port, which is bored at the bottom of the groove at the center of the fixed spiral portion 13 and opens into the closed container 18 . 25 is a discharge gas passage;
It is connected to the condenser 2 (FIG. 1). Reference numeral 26 denotes an injection hole, which is guided to the outside of the closed container 18 by the conduit 7 through passages 27 and 28.

FIGS. 4 and 5 show an orbiting scroll. In the swirling spiral portion 14, swirling vanes 29 having an involute curve formed by the curve drawn by the tip of the thread when the thread wound around the base circle is unwound are formed with appropriate thickness and height. 29a is a terminal portion.

6 and 7 are fixed scrolls. The fixed spiral portion 13 is formed with an involute curved blade 30 that meshes with the swirling blade 29, and its terminal end reaches 30a. A discharge hole 31 is bored in the center of the blade 30. 32 is a fixed blade 30
A plurality of injection holes are provided along the inner wall of the groove bottom 34 of the fixed spiral portion 13 . The size of the injection hole 32 is smaller than the plate thickness of the swirl vane 29. Further, they are provided along the corners so as to be in contact with the wall surface of the fixed blade 30. 33 is an injection hole provided along the outer wall of the fixed blade 30. As long as these plurality of injection exit holes 32 and 33 are within the range of the blade winding angle from the state where the ends of the blades of the fixed scroll and the orbiting scroll are closed to the state where the internal pressure of the suction gas confinement chamber is equal to the injection pressure, The holes may be continuously drilled with very small intervals between the holes. Further, as shown in FIG. 8, the interval may be left a little. By appropriately changing the position of the injection hole, the range of injection can be adjusted. FIG. 8 shows a state in which the above-mentioned fixed vane and swirling vane are combined, and 35 and 36 are spaces in which the suction gas is confined by the swirling vane terminal end 29a and the fixed vane terminal end 30a. This is an example in which holes 37 and 38 are bored with a plurality of injection holes with a slight distance between the holes.

Figure 9 shows the injection holes as long holes 39 and 40.
This shows the case when In this case, the width of the elongated hole is the same as the diameter of a circular single hole (i.e.,
(smaller than the plate thickness dimension of the swirl vane 29), and grooves are formed in the longitudinal direction.

Next, its effect will be explained. (See FIG. 1) During the refrigeration cycle operation, low-pressure refrigerant gas from the evaporator 6 is sucked into the scroll compressor 1. The suction gas flows from the suction passage 22 (FIG. 2) through the passage 23 leading into the spiral groove, and flows into the crankshaft 16.
The blade end portion 29a of the rotating whirlpool 14 which is driven to precess, and the blade end portion 30 of the fixed whirlpool 13.
The suction gas trapped by a is gradually reduced toward the center. In this way, the gas is compressed and pressurized within the chamber. In this process, the gas separated by the gas-liquid separator (Fig. 1) is injected via the electromagnetic valve 8 into the chamber that confines the suction gas from the compression process, but the range in which this injection is possible is within the range where the pressure in the chamber is equal to the injection pressure. It is only a small amount until it becomes equal to . However, in the present invention, since a plurality of continuous injection holes are provided, sufficient injection can be performed immediately after the suction gas is trapped until the internal pressure in the chamber becomes equal to the injection pressure. The injected refrigerant gas is compressed and discharged together with the refrigerant gas taken in from the main circuit. The discharged compressed refrigerant gas exchanges heat with a heat exchange fluid such as air or water in a condenser 2 (FIG. 1), and is condensed and liquefied. on the other hand,
The heat exchange fluid is used as a heating heat source in the case of space heating, and is radiated into water in the case of air conditioning. The condensed liquefied refrigerant is reduced in pressure to an intermediate pressure by the first pressure reduction mechanism 3 and flows into the gas-liquid separator 4 . The interior of the gas-liquid separator 4 is saturated at an intermediate pressure, with the upper part filled with gas and the lower part filled with liquid. The gas is then injected via the solenoid valve 8 into the suction gas confinement space via the conduit 7 as described above. on the other hand,
The condensed liquid in the gas-liquid separator 4 is depressurized and expanded to pressure by the second decompression mechanism 5, flows into the evaporator 6, exchanges heat with a heat exchange fluid such as air or water, and is superheated. and is sucked into the scroll compressor 1 again. The amount of refrigerant gas to be injected varies depending on the total area of the injection holes and the position of the final hole, and the range of injection can be adjusted by appropriately changing the position of the final hole. The greater the amount of injection, the greater the amount of refrigerant gas discharged.
During heating operation, the heating state increases.

FIG. 9 shows an example in which elongated holes are used instead of a plurality of holes to further increase the passage area. This is more advantageous than providing a plurality of holes because the gaps between the holes are eliminated and the holes are continuous, which further reduces the pressure loss in the passage.

Therefore, by increasing the number of injection holes and increasing the passage area, the passage resistance is reduced and the amount of injection can be increased. And heating capacity can be increased without increasing the capacity of the compressor. In addition, compared to those that use a heater or the like, the cost and coefficient of performance are better, and power is saved. In addition, since a plurality of circular injection holes are connected or formed into elongated holes, the injection time can be extended, resulting in a significant improvement in performance.

FIGS. 10 and 11 are sectional views of essential parts of a scroll compressor (hereinafter referred to as a "prototype compressor") that was prototyped in parallel with research for the present invention.

The prototype compressor shown in FIG.
The diameter of the injection hole 41 communicating with 28 is made larger than the thickness of the swirling blade 29, and the fixed blade 30
The diameter of the hole is smaller than the total thickness dimension of both the rotary blade 29 and the rotating blade 29, and the hole is bored parallel to the blade direction, extending over both sides of the wall of the fixed blade 30 and the groove bottom surface 34 of the fixed scroll. According to this configuration, the area per hole is large, so it was expected that the passage resistance would be low. However, if the hole diameter is made larger than the blade thickness as in this proposal, the gas shutoff performance will be poor, and the gas It was confirmed that this method is not practical as it causes a lot of leakage and reduces efficiency.

Further, in the compressor of the trial design shown in FIG. 11, the injection extension holes 42 are bored at an angle with respect to the blades. Since there was no part like the collision wall 43 at the end, it was hoped that the flow resistance would be low, but as long as the hole diameter was larger than the blade thickness, it would be impractical due to gas leakage similar to the previous proposal (Figure 10). It was judged.

From these experimental results, in order to exhibit the functions of the present invention and obtain practical effects, it is essential that the pore diameter be smaller than the blade thickness.

Since the present invention is constructed as described above, the performance can be sufficiently increased by injection.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle system diagram, Fig. 2 is an involute curve diagram, Fig. 3 is a sectional view of the scroll compressor of the present invention, Fig. 4 is a plan view of the swirling whirlage, and Fig. 5 is the same as Fig. 4. 6 is a plan view of the fixed spiral, FIG. 7 is a sectional view of FIG. 6, FIG. 8 is a plan view of the fixed spiral and the rotating spiral, and FIG. FIGS. 10 and 11, which are plan views of other embodiments in which the swirling whirlpools are combined, are sectional views of the vicinity of the injection hole in the prototype scroll compressor, respectively. 1... point scroll compressor, 2... condenser, 3
...First pressure reducing mechanism, 4... Gas-liquid separator, 5... Second pressure reducing mechanism, 6... Evaporator, 7... Conduit, 8...
Solenoid valve, 9...base circle, 10...thread, 11...end,
12...Compressor part, 13...Fixed spiral part, 14...
... Rotating spiral portion, 15 ... Frame, 16 ... Crankshaft, 17 ... Bearing, 18 ... Sealed container, 19
...Fixed coil part, 20...Rotating rotor part, 21
...oil sump section, 22...refrigerant gas passage, 23...passage, 24...discharge port, 25...discharge gas passage, 2
6... Injection hole, 27, 28... Passage, 29... Swivel vane, 30... Vane, 31...
Fixed spiral portion, 32, 33... Injection hole, 34... Groove bottom surface, 35, 36... Space, 3
7, 38... Injection hole, 39, 40...
...Long hole, 41, 42...Injection hole, 4
3... Collision wall.

Claims (1)

[Claims] 1 scroll compressor, condenser, first pressure reduction mechanism,
A refrigeration cycle is formed by a gas-liquid separator, a second pressure reduction mechanism, and an evaporator, and an injection hole is bored along the involute tooth profile of the fixed scroll of the scroll compressor, so that the end portion of the blade winding of the fixed scroll and the orbiting scroll is formed. In a scroll compressor in which an injection hole communicates with a suction gas confinement chamber between a closed state and a state in which the internal pressure of the suction gas confinement chamber becomes equal to the injection pressure, intermediate pressure refrigerant gas is injected from a gas-liquid separator. Within the range of the winding angle from the state where the end of the blade of the fixed scroll and the orbiting scroll are closed to the state where the internal pressure of the suction gas confinement chamber is equal to the injection pressure, the boundary between the fixed scroll blade and the groove bottom surface. A plurality of circular holes or one long hole are opened on the inside and outside of the fixed blade, respectively, and the diameter of the circular hole or the width of the long hole is made smaller than the thickness of the swirling blade. A scroll compressor featuring: