JPH11107968A - Compressor injection device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the efficiency at the time of low-load operation by using a mechanism for shutting off and canceling the injection. SOLUTION: An injection path 5 to a compression chamber 13 is provided.
0, the injection path 50 is opened so that the injection is performed, and the upstream side 50a of the injection path 50 is closed to shut off the injection and the downstream side 50b.
A switching valve 56 is provided for switching between an injection cutoff state and a suction flow path through which the fluid flows into the suction path 60 to the compression chamber 13. In the injection cutoff state, a part of the compressed fluid in the compression chamber 13 is bypassed to the suction path 60, and the discharge flow Achieves the above object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device for a compressor in which a fluid to be compressed is injected into various compressors so as to supercharge the fluid to be compressed, and is mainly used for refrigeration and air conditioning for business and home use. The present invention relates to an injection device for a compressor to be used.

[0002]

2. Description of the Related Art Electric compressors for refrigeration and air conditioning include those having a reciprocating compressor, a rotary compressor and a scroll compressor. Currently, it is growing by making use of its features in terms of cost and performance. Among them, scroll type compressors have been put to practical use taking advantage of the features of high efficiency, low noise, and low vibration.

[0003] Japanese Patent Application Laid-Open No. 08-144971 discloses a non-return valve for supplying intermediate-pressure refrigerant gas separated by a gas-liquid separator to a compression chamber formed between a fixed scroll and an orbiting scroll in a scroll compressor. Injecting through, utilizing the gradual compression characteristic of scroll compressors,
A device that realizes stable and efficient gas injection is disclosed.

[0004]

By the way, the diversification of the operation modes is performed by operating the compressor at a variable speed by inverter control or the like so that an optimum operation state can be obtained at each time. Depending on the operation mode, it may be necessary to cut off or cancel the cutoff even if it is performed during high load operation such as heating, which is a high speed operation, but is shut off during low load operation such as cooling, which is a low speed operation. Is coming.

[0005] However, in order to appropriately perform such a variable speed operation and to shut off and release the gas injection, in the above-described conventional apparatus, regardless of the difference in the operating speed and the shutoff and release of the gas injection, the compression capacity is not changed. Is kept constant, there is a limit in securing the efficiency of the minimum or intermediate low-load operation, and the efficiency cannot be sufficiently increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an injection device for a compressor that can increase the efficiency during low-load operation by utilizing a mechanism for shutting off and canceling the injection.

[0007]

The displacement of the compression chamber from the suction position to the discharge position reduces the hermetic volume, and compresses the fluid sucked from the duty cycle at the suction position and discharges the fluid to the duty cycle at the discharge position. In order to achieve the above object, an injection device for a compressor that injects a gas fluid separated into gas and liquid during a load cycle into a compression chamber, in order to achieve the above object, the present invention provides an injection path in the middle of an injection path to the compression chamber. A switching valve is provided that switches between an injection state in which the injection is performed by opening the injection path, and an injection cutoff state in which the injection path is closed by closing the upstream side of the injection path and shutting off the injection side while the downstream side is connected to the suction path to the compression chamber. This is one of the features.

In such a configuration, the switching valve is set to the injection state during the high-load operation of the load cycle to supercharge the fluid to be compressed, and the discharge flow rate is increased to thereby increase the load cycle during the high-load operation. High-efficiency operation, and during low-load operation, the switching valve is shut off to eliminate injection supercharging, and a part of the compressed fluid in the compression chamber is compressed downstream of the injection path and through the switching valve. By bypassing to the suction path to the chamber, the actual volume of the compression chamber is kept as it is, but the discharge flow rate corresponding to the smaller volume is suppressed, so that the duty cycle operation at low load operation can be achieved with high efficiency. . Therefore, high efficiency is achieved from low load operation to high load operation, and annual power consumption is reduced. Especially effective when the ratio of low-load operation is high, such as switching to low-load operation after starting up to the set temperature early with high-load operation, or switching to low-load operation during sleeping or for a predetermined time during sleep. It is.

According to the present invention, a position on the injection path where the switching valve is provided is a path for restricting a bypass flow rate within a predetermined range for bypassing the compressed fluid in the compression chamber to the suction path to the compression chamber in the injection cutoff state. A further feature is that the resistance is set to be obtained.

In such a configuration, when the compressed fluid in the compression chamber is bypassed to the suction path to the compression chamber in the injection cutoff state, the compressed fluid in the compression chamber is compressed by setting the position of the switching valve in the injection path. By controlling the passage resistance when bypassing the suction path to the chamber, the bypass flow rate can be regulated within a predetermined range,
In any injection structure, a predetermined bypass amount without excess or shortage can be realized, and high efficiency during low load operation can be guaranteed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a typical embodiment of the present invention will be described in detail with reference to FIG.

This embodiment is an example of a case where a horizontally mounted scroll compressor for refrigeration and air conditioning is used, and FIG. 1 shows a configuration of a main part.

To explain this, a scroll-type compression mechanism 2 is provided at one end, an electric motor 3 for driving the compression mechanism 2 at an intermediate portion, and a closed container 1 is provided at the other end in the closed container 1.
And an oil pump 6 for sending out the oil 4 in the oil reservoir 5 at the lower part of the oil reservoir to the lubrication target part.

The compression mechanism 2 includes the end plate 1 of the fixed scroll 11.
The blade 11a rising from 1d and the orbiting scroll 1
The blades 12a rising from the second end plate 12d are meshed with each other in the same manner as in the related art, and the orbiting scroll 12 is driven to rotate in a circular orbit without rotating, thereby forming a pair of compression chambers 13 formed therebetween. Suction port 1 provided on end plate 11d of fixed scroll 11 shown in FIG.
4, the end plate 11 of the fixed scroll 11
While moving to the center side communicating with the discharge port 15 provided in d, the closed volume is reduced and compression is performed to discharge.

The support and drive and the structure for guiding the fluid to be sucked, compressed and discharged in the closed vessel 1 may be configured in any manner. Further, the oil pump 6 may be of any type. In the first embodiment, the compression mechanism 2 is integrated with the main bearing member 9 fixed to one end side by bolting the fixed scroll 11 to the main bearing member 9.
The orbiting scroll 12 meshed with the fixed scroll 11 is sandwiched between the fixed scroll 11 and the fixed scroll 11. The electric motor 3 includes an annular stator 3a fixed to the closed container 1 by welding or the like, and a rotor 3b disposed inside the stator 3a.
A crankshaft 16 for orbiting the orbiting scroll 12 of the compression mechanism 2 is fixed to the rotor 3b.

The crankshaft 16 is supported at the other end of the closed casing 1 by an auxiliary bearing member (not shown) fixed to the closed casing 1 by welding or the like, and the main shaft 18 on the opposite side is supported by the main bearing member 9. I have. The auxiliary bearing member and the main bearing member 9 have a slide bearing 21 and the like for the bearing. The main shaft 18 is fitted with a revolving shaft 12b protruding to an eccentric position on the back surface of the end plate 12d of the revolving scroll 12 via an eccentric bearing 23 held so as to be able to reciprocate on the diameter line of the main shaft 18, and when the main shaft 18 is rotated, The cooperation of the Oldham ring 28 provided between the bearing member 9 and the orbiting scroll 12 causes the orbiting scroll 12 to orbit so as to make a circular orbital motion without rotating with respect to the fixed scroll. However, the bearing structure as described above can be variously modified.

Since the first embodiment is a scroll compressor for refrigeration and air conditioning, suction by a compression mechanism 2 is performed.
The fluid to be compressed and discharged is a refrigerant, and especially when using a refrigerant containing no chlorine, for example, a hydrogen fluoride-carbon-based refrigerant, an oil 4 compatible with the refrigerant is used. Even if this is not the case, the oil 4 is compatible with the oil 4 and is carried by the refrigerant to the mechanically slidable parts of each part in the closed container 1, thereby improving lubricity.

A gas suction pipe 32 is connected to the suction port 14, and a gas discharge pipe (not shown) on the side opposite to the gas suction pipe 32 is connected to the discharge port 15.
It is connected through the upper refrigerant passage 33.

The oil pump 6 is driven by the crankshaft 16 together with the compression mechanism 2, sends out the oil 4 in the oil reservoir 5 to an oil passage 35 formed vertically through the crankshaft 16, and first supplies the oil 4 to the eccentric bearing 23. Eccentric bearing 2
A part of the oil 4 after being supplied to 3 is supplied to the sliding bearing 21 and the compression mechanism 2 through respective gaps and a predetermined passage, and the rest is returned to the lower oil reservoir 5.

Further, the discharge port 15 is provided with a check valve 42 for preventing the orbiting scroll 12 from rotating backward when the compression mechanism 2 is stopped, and a check valve stopper 43 for restricting the movement of the orbiting scroll 12. .

Between the gas discharge pipe and the suction pipe 32, as shown in FIG. 1, a condenser 44, an expansion valve 45, a gas-liquid separator 46, a capillary tube 47, and an evaporator 48 are used for refrigeration and air conditioning. Are connected in sequence, and a heat pump type refrigeration cycle including the compression mechanism 2 in the closed vessel 1 is connected in a ring as a whole, so that low-load cooling and high-load heating can be performed. Yes,
For this purpose, it is assumed that a switching structure (not shown) is provided.

The end plate 11d of the fixed scroll 11, which is a fixed member forming the compression chamber 13, is provided on the end plate 11d of FIGS.
As shown in FIG. 3, an injection pipe 52 for performing gas injection to one or both of the pair of compression chambers 13 is connected, and an injection port 51 extending from an inlet 85 from the injection pipe 52 to the compression chamber 13 in a substantially wall thickness direction. Is provided. A gas refrigerant supply pipe 53 from the gas-liquid separator 46 is connected to the injection pipe 52. As a result, the gas refrigerant in the gas phase separated by the gas-liquid separator 46 in the compression chamber 13 is supplied with the refrigerant supply pipe 53 and the injection pipe 5.
2. It is injected into the compression chamber 13 through the injection port 51. Since such gas injection increases the efficiency of the compressor in the compression mechanism 2,
The heating capacity is improved accordingly.

According to the diversification of the operation of the refrigeration cycle,
The gas injection may be performed in a timely manner according to the operation state of the refrigeration cycle. In order to control the shutoff and the release of the shutoff, a three-way solenoid valve 5 is provided in the middle of the refrigerant supply pipe 53.
6 is provided, and can be appropriately switched together with the switching between the cooling and heating operations of the refrigeration cycle. This switching control can be performed by a microcomputer together with the operation control of the refrigeration apparatus, for example, but is not particularly limited to this. Further, in order to diversify the operation, in this embodiment, in addition to the heat pump type which can be used for cooling and heating, the electric motor 3 is controlled by, for example, an inverter so that the orbiting scroll 12 can be orbitally driven at a variable speed. It is.

In particular, in the present embodiment, the three-way solenoid valve 56
FIG. 1A shows that the injection path 50 is opened in the middle of the injection path 50 formed by the refrigerant supply pipe 53, the injection pipe 52, and the injection port 51 to the compression chamber 13 so that the injection is performed. Injection state, the injection side is closed by closing the upstream side 50a of the injection path 50, and the downstream side 50b is connected to the compression chamber 1
A switching valve for switching to an injection cut-off state shown in FIG.

Thus, during high load operation such as heating operation of the refrigeration cycle, the three-way solenoid valve 56 is set to the injection state shown in FIG. 1A to supercharge the refrigerant which is the fluid to be compressed. By increasing the discharge flow rate, the refrigeration cycle can be operated with high efficiency. At the time of low load operation such as cooling operation, the three-way solenoid valve 56 is set to the injection cutoff state shown in FIG. Along with eliminating supercharging due to the injection of the refrigerant, a part of the compressed refrigerant that is the compressed fluid in the compression chamber 13 is bypassed to the suction path 60 to the compression chamber 13 through the downstream side 50 b of the injection path 50 and the three-way solenoid valve 56. In this case, the actual volume of the compression chamber 13 is kept as it is, and the discharge flow rate corresponding to the smaller volume is suppressed. The operation of the refrigeration cycle during low load operation including condition can be achieved with high efficiency. Therefore, high efficiency is achieved from low load operation to high load operation, and annual power consumption is reduced. Especially effective when the ratio of low-load operation is high, such as switching to low-load operation after starting up to the set temperature early with high-load operation, or switching to low-load operation during sleeping or for a predetermined time during sleep. It is.

Such effects do not change even if the type of compressor and the type of load cycle connected to the compressor are different, and these various types also belong to the scope of the present invention.
Also, the three-way solenoid valve 56 is also in the injection state,
Any switching type can be adopted as long as the injection cutoff state is obtained. The position on the injection path 50 where the three-way solenoid valve 56 is provided is the injection cutoff state shown in FIG. Is set so as to obtain a passage resistance that restricts a bypass flow rate for causing the compressed refrigerant of the above to bypass the suction path 60 to the compression chamber 13 within a predetermined range. This setting depends on the difference in length of the injection pipe 52 in the injection path 50, the connection structure of the injection pipe 52 to the fixed scroll 11, the connection structure of the inlet port 85 and the injection port 51, and the like. This is performed according to the difference in various factors that affect the passage resistance, such as the difference in the size and shape of the dead volume formed in the inside.

In this way, in the injection cutoff state shown in FIG. 1B, the compressed refrigerant in the compression chamber 13 bypasses the suction path 60 to the compression chamber 13 while the injection path of the three-way solenoid valve 56 By setting the position at 50, the passage resistance when the compressed refrigerant in the compression chamber 13 is bypassed to the suction path 60 to the compression chamber 13 can be controlled, and the bypass flow rate can be regulated within a predetermined range.
In any injection structure, a predetermined bypass amount without excess or shortage can be realized, and high efficiency during low load operation can be guaranteed.

As one example of the present embodiment, as shown in FIG. 1, by providing a capillary tube 80 extending from the inlet 85 in the injection pipe 52, the passage resistance in the dead volume is increased. Thus, the three-way solenoid valve 56 can be provided near the injection position. As a result, the bypass path is shortened, and the bypass path can be provided around the compressor.

Although not shown, one of the pair of compression chambers has a prescribed compression at a predetermined low speed operation of the blades forming a pair of compression chambers between the fixed scroll and the orbiting scroll with variable speed. From the spiral length position satisfying the ratio to the winding end, an offset surface is provided to open the one compression chamber to the suction port side with a predetermined gap so as not to be sealed, and the one compression chamber is not sealed. When the injection port is provided at a position that sequentially communicates with the area and the other compression chamber that is sealed without the offset surface, the capacity at the time of bypass can be further reduced, and the capacity variable width can be increased.

[0030]

According to one feature of the present invention, the switching valve is set to an injection state during high load operation to supercharge the fluid to be compressed, and the discharge flow rate is increased to increase the discharge flow during high load operation. The load valve can be operated with high efficiency, and during low-load operation, the switching valve is in the injection cutoff state to eliminate supercharging due to injection, and a part of the compressed fluid in the compression chamber is switched to the downstream side of the injection path and switched. By bypassing to the suction path to the compression chamber through the valve, the discharge flow rate corresponding to a smaller volume than the actual volume of the compression chamber can be suppressed, and the operation of the duty cycle at the time of low load operation can be achieved with high efficiency. Therefore, high efficiency is achieved from low load operation to high load operation, and annual power consumption is reduced. Especially effective when the ratio of low-load operation is high, such as switching to low-load operation after switching to low-load operation after the start-up at high-load operation to the set temperature, or switching to low-load operation during bedtime or while sleeping. It is.

According to a further feature of the present invention, by setting the position of the switching valve in the injection path, the path resistance when the compressed fluid in the compression chamber is bypassed to the suction path to the compression chamber is controlled, and the bypass flow rate is reduced. It can be regulated to a predetermined range, realizes a predetermined bypass amount without excess or shortage in any injection structure,
High efficiency during low load operation can be guaranteed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a scroll compressor according to a typical embodiment of the present invention, in which (a) shows an injection state and (b) shows an injection cutoff state.

[Explanation of symbols]

 2 Compression Mechanism 3 Electric Motor 11 Fixed Scroll 11d End Plate 12 Orbiting Scroll 13 Compression Chamber 14 Suction Port 15 Discharge Port 46 Gas-Liquid Separator 50 Injection Path 51 Injection Port 52 Injection Pipe 53 Refrigerant Supply Pipe 56 Three-Way Solenoid Valve 85 Introduction Port

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Tsubagawa 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] The closed space is reduced by the displacement of the compression chamber from the suction position to the discharge position, and the fluid sucked from the duty cycle is compressed at the suction position and discharged to the duty cycle at the discharge position. In the injection device of the compressor that injects the gas fluid separated into gas and liquid into the compression chamber, an injection state in which the injection path is opened and the injection is performed in the middle of the injection path to the compression chamber, and an injection state of the injection path. An injection device for a compressor, comprising: a switching valve that switches between an injection shut-off state in which an upstream side is closed to shut off injection and a downstream side is connected to a suction path to a compression chamber. 2. A position on the injection path where the switching valve is provided is a path resistance that restricts a bypass flow rate for bypassing the compressed fluid in the compression chamber to a suction path to the compression chamber in a predetermined range in the injection cutoff state. The injection device for a compressor according to claim 1, wherein the injection device is set as follows.