JPS6160341B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system, and more particularly, to a refrigeration system that is equipped with a capacity control mechanism that controls the capacity of a compressor and that can perform refrigeration operation at a capacity that corresponds to the refrigeration load.

Conventionally, as described in, for example, Japanese Utility Model Publication No. 46-19867, and as schematically shown in FIG. A compressor 50 is connected between the intermediate port 54 and the low pressure gas path.
A bypass pipe 55 disposed outside the frame is connected, a solenoid valve 56 is interposed in the middle of the bypass pipe 55, and the solenoid valve 56 is closed or opened depending on the size of the refrigeration load. It is known that a full capacity operation is performed in which the effective volume of the cylinder 51 is maximized, and a partial capacity operation is performed in which the effective volume of the cylinder 51 is reduced.

By the way, as shown in FIG. 5, an evaporator 57 and a condenser 58 are connected to the compressor 50 to form a refrigerant circuit, and an expansion mechanism is used to set the evaporation pressure of one evaporator 57 in the refrigerant circuit. Conventionally, when an inexpensive capillary reach tube 59 is used, one capillary reach tube 59 is used.
Since the pressure was reduced during full-capacity/partial-capacity operation, the amount of gas discharged from the compressor 50 (=refrigerant circulation amount) was larger during full-capacity operation and larger during partial-capacity operation, corresponding to the effective volume of the cylinder 51. Due to this, there was a drawback that appropriate refrigerant connections could not be made during each operation.

That is, in the past, the resistance value of the capillary reach tube 59 was determined based on the full capacity operation, so the resistance value was too small during partial capacity operation, and the liquid was not sealed at the inlet of the capillary reach tube 59. There were problems in that flash gas flows through the capillary reach tube, causing flash noise and a decrease in effective energy ratio (hereinafter referred to as EER).

Therefore, the present invention was devised to solve the conventional problems as described above, and includes switching between full-capacity operation and partial-capacity operation, and adjusting an appropriate amount of pressure reduction according to each operating capacity at this time. By performing the operations simultaneously and in conjunction with each other, during each of the above operations,
It is an object of the present invention to provide a refrigeration system that can reliably perform proper refrigerant connection, prevent a decrease in EER during partial capacity operation, and prevent the generation of flashing noise.

Embodiments of the present invention will be described below based on the drawings.

As schematically shown in FIG. 1, the refrigeration system of the present invention comprises a compressor 1 incorporating a capacity control mechanism 4, a condenser 2, a solenoid valve SV and an auxiliary capillary reach tube 6.
The refrigerating circuit is equipped with a refrigeration circuit in which a capillary reach tube 5 and an evaporator 3 are connected in series, and the refrigerant is circulated as shown by the arrow by the operation of the compressor 1.

The compressor 1, as shown in FIGS. 2 and 3,
A motor 11 and a compression mechanism 12 are housed inside a closed casing 10, and both 11 and 12 are connected by a shaft 13. 15
It consists of a cylinder 16 interposed between the cylinders 16 and a rotor 17 having a vane 18 installed in the cylinder chamber 16a of the cylinder 16, and the rotor 17 is connected to the shaft 1.
It is connected to 3. The upper frame 14 is provided with a suction passage 20, one end of which communicates with the suction port 1a and the other end of which communicates with the suction passage 19, and the cylinder 16 has one end connected to the cylinder chamber 16a. The casing 10 is open and the other end is
A discharge path 21 having a discharge port 1b opening inward is provided.

Therefore, the present invention is characterized in that, firstly, the refrigerant circuit connected to the suction port 1a and the discharge port 1b of the compressor 1 is provided with a main capillary reach tube 5 having a resistance suitable for the capacity during partial capacity operation. , and the auxiliary capillary reach tube 6 are connected in parallel, and a solenoid valve SV is provided on the inlet side of the auxiliary capillary reach tube 6.

Second, the capacity control mechanism 4 incorporated into the compressor 1 is constructed as follows, and this capacity control mechanism 4 is linked to the electromagnetic valve SV.

That is, in the frame of the compressor 1, one end is connected to the suction port 1a of the cylinder chamber 16a, and the other end is connected to the cylinder chamber 1.
A bypass passage 7 that opens at an intermediate portion between the suction port 1a and the discharge port 1b of 6a is provided, and an opening/closing valve 8 for opening and closing the bypass passage 7 is provided in this bypass passage 7, and a back pressure chamber of this opening/closing valve 8 is provided. 9, the solenoid valve SV
and the auxiliary capillary reach tube 6, and by opening and closing the solenoid valve SV, the pressure in the back pressure chamber 9 is changed in height to open and close the on-off valve 8. The compressor 1,
It is possible to switch between full capacity and partial capacity operation.

Therefore, the resistance values of the auxiliary capillary reach tube 6 and the main capillary reach tube 5 are such that when the solenoid valve SV is opened during full capacity operation, the high pressure liquid refrigerant condensed in the condenser 2 is transferred to both tubes 6, 5, and by closing the solenoid valve SV during partial capacity operation, the high-pressure liquid refrigerant condensed in the condenser 2 flows only to the main capillary reach tube 5. The value is selected so that the pressure can be reduced appropriately.

Further, the on-off valve 8 has a valve chamber 22 provided below the intermediate opening of the bypass passage 7 to the cylinder chamber 16a, and a metal poppet valve 81 is movably housed within the valve chamber 22.

Further, the on-off valve 8 is a metal poppet valve 81.
A spring 23 is provided between the upper surface of the flange formed at the lower part of the valve chamber 22 and the upper step of the valve chamber 22, and the spring 23 urges the opening direction, and a sealing material 24 is provided on the lower surface of the flange, The back pressure chamber 9 is formed between this sealing material 24 and a plug 25 that is screwed into the lower end of the valve chamber 22. Therefore, the pressing force Fs of the spring 23
In the case where the back pressure chamber 9 is communicated with the high pressure part of the refrigerant circuit, the pressing force (force in the closing direction) on the opening/closing valve 8 due to the high pressure and the pressure in the valve chamber 22 on the opening/closing valve 8 are
It is selected so that it is smaller than the difference with the pressing force (in the opening direction).

Further, in order to connect the back pressure chamber 9 to a position 26 between the solenoid valve SV and the auxiliary capillary reach tube 6, an upper frame 1 of the compressor 1 is provided.
4. Connecting path 2 to cylinder 16 and lower frame 15
7, the lower end of this communication path 27 is communicated with the back pressure chamber 9, the upper end is opened to the outside from the upper frame 14, and this opening is provided with a connecting pipe 28. A communication pipe 29 is connected between the connecting position 26 and the connecting position 26 . In FIGS. 2 and 3, 30 is a discharge passage, 31 is a suction valve, and 32 is a discharge valve.

Therefore, in the above configuration, when the refrigeration load is small and the compressor 1 is operated at partial capacity, the solenoid valve SV is first closed. When the solenoid valve SV is closed, the back pressure chamber 9 is connected to the low pressure circuit on the outlet side of the main capillary reach tube 5,
The auxiliary capillary reach tube 6 and the communication pipe 29
The pressure is equalized through communication, creating a low pressure area. Thus, the force F ₁ that presses the on-off valve 8 in the closing direction is the combination of the force that presses the on-off valve 8 in the opening direction due to the pressure in the valve chamber 22 (the pressure in the middle part of the cylinder chamber), and the force that presses the on-off valve 8 in the opening direction. Since the pressure becomes smaller than the sum F ₂ with the pressure FS, the on-off valve 8 opens and the bypass passage 7 opens. Therefore, no compression is performed between the suction port 1a of the compressor 1 and the intermediate opening where the bypass passage 7 opens, and the compressor 1 operates at partial capacity, reducing the amount of discharged gas.

The refrigerant discharged from the compressor 1 in the partial capacity operating state as described above is condensed in the condenser 2 and flows into the main capillary reach tube 5 as high-pressure liquid refrigerant. By the way, since the resistance of the main capillary reach tube 5 is a value suitable for the refrigerant circulation amount _Q1 during partial capacity operation, the inflowing refrigerant is
The pressure is appropriately reduced to a predetermined low pressure. Then, it is evaporated in the evaporator 3 and sucked into the compressor 1 at an appropriate degree of superheat, so that partial capacity operation corresponding to a small refrigeration load is properly performed.

As described above, since the bypass passage 7 opened during partial capacity operation is formed using the inside of the bridge of the compressor 1, the cross-sectional area of the passage 7 is smaller than that when the bypass passage is provided outside the bridge. The pressure drop of the refrigerant bypassing from the bypass passage 7 can be almost eliminated,
Minimizes energy loss due to pressure drop,
This makes it possible to prevent a decline in EER.

Next, when the compressor 1 is operated at full capacity, the solenoid valve SV is opened. That is, when the solenoid valve SV is opened, the back pressure chamber 9 is connected to the high pressure circuit section on the outlet side of the condenser 2, the solenoid valve SV and the communication pipe 2.
9 to equalize the pressure and press the on-off valve 8 in the closing direction, the force F ₁ that presses the on-off valve 8 in the closing direction is combined with the force that presses the on-off valve 8 in the opening direction due to the pressure P ₂ of the valve chamber 22, and the pressing force of the spring 23 When the sum of Fs and Fs becomes larger than ₂ , the on-off valve 8
is closed, and the bypass passage 7 is closed. Therefore, the compressor 1 operates at full capacity, and the amount of discharged gas increases.

In this way, the refrigerant discharged from the compressor 1 which is in full capacity operation is condensed and liquefied in the condenser 2,
This liquefied refrigerant is divided into the main capillary reach tube 5 and the auxiliary capillary reach tube 6, each of which is appropriately reduced in pressure to the predetermined low pressure, evaporated in the evaporator 3, and transferred to the compressor 1 at an appropriate degree of superheat.
It is inhaled.

As described above, during full capacity operation, the high-pressure liquid refrigerant is divided into both capillary reach tubes 5 and 6 and is subjected to excessive resistance, so that when it flows out of the condenser 2, it can be in a supercooled state with just the right amount of overcooling and condensation. This allows Vessel 2 to effectively demonstrate its abilities. In addition, since the high-pressure liquid refrigerant is appropriately depressurized by both capillary reach tubes 5 and 6, it can be in a state of just the right degree of superheating when flowing out of the evaporator 3, and the compressor 1 can be operated at full capacity reliably and stably. It can be done.

Furthermore, when starting the partial capacity and full capacity operations as described above, if the solenoid valve SV is closed, the compressor 1 can be operated in the partial capacity operation state with the on-off valve 8 open. The applied load can be reduced, and the compressor 1 can be started easily.

As described above, according to the present invention, the solenoid valve
By opening the SV, high pressure is introduced into the back pressure chamber 9 of the on-off valve 8, and the on-off valve 8 closes the bypass passage 7 to perform full capacity operation. The condensed high-pressure liquid refrigerant can be divided into the main capillary reach tube 5 and the auxiliary capillary reach tube 6 to appropriately reduce the pressure.
By simply opening the SV, it is possible to control the switch to full capacity operation and adjust the appropriate amount of pressure reduction commensurate with this full capacity operation, simultaneously and in conjunction with each other.

Furthermore, by closing the solenoid valve SV,
Low pressure is introduced into the back pressure chamber 9 of the on-off valve 8, and the on-off valve 8 opens the bypass passage 7 to perform partial capacity operation, and the condenser 2
The high-pressure liquid refrigerant condensed in can be appropriately depressurized by flowing only through the main capillary reach tube 5, and switching control to partial capacity operation can be performed simply by closing the solenoid valve SV. The appropriate adjustment of the amount of pressure reduction commensurate with this partial capacity operation can be performed simultaneously and in conjunction with the adjustment.

As described above, switching between full capacity operation and partial capacity operation can be performed only by opening and closing the solenoid valve SV.
At this time, the amount of pressure reduction is adjusted simultaneously and in conjunction with the amount depending on the capacity, so whether it is in full capacity operation or partial capacity operation, it can be adjusted reliably depending on the operation. This allows an appropriate amount of pressure reduction to be achieved, the evaporator 3 can always be heated to an appropriate temperature with just the right amount, and the compressor 1 can be operated reliably and stably. EER became a problem
Problems such as a drop in performance and the occurrence of flashing noises have now been reliably resolved.

In addition, according to the present invention, when the solenoid valve SV is closed at the start of operation,
Since the compressor 1 can be operated in a partial capacity operating state with the on-off valve 8 open, the load applied to the compressor 1 can be reduced. Another advantage is that the compressor 1 can be started easily.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant piping system diagram showing one embodiment of the present invention, Fig. 2 is an enlarged vertical cross-sectional view of only the compressor, Fig. 3 is an enlarged cross-sectional view of the compressor, and Figs. 4 and 5 are conventional It is an explanatory diagram of an example. 1... Compressor, 1a... Suction port, 1b... Discharge port, 2... Condenser, 3... Evaporator, 5... Main capillary reach tube, 6... Auxiliary capillary reach tube, 7... Bypass Passage, 8...Opening/closing valve, 9...
...Back pressure chamber, 16a...Cylinder chamber, SV...Solenoid valve.

Claims (1)

[Claims] 1 The compressor 1, condenser 2, and evaporator 3 are connected in sequence, and one end is connected to the cylinder chamber 16a of the compressor 1.
A bypass passage 7 is provided at the suction port 1a of the cylinder chamber 16a, the other end of which opens at an intermediate portion between the suction port 1a and the discharge port 1b of the cylinder chamber 16a.
An on-off valve 8 that opens and closes the bypass passage 7 is provided, and the capacity of the compressor 1 is switched between full capacity and partial capacity by the opening and closing operation of this on-off valve 8, and the full capacity operation and partial capacity operation are selectively performed. The refrigeration system is constructed as shown in FIG.
In addition to interposing a parallel circuit with a series circuit with the auxiliary capillary reach tube 6 provided with the SV on the exit side,
A connection between the solenoid valve SV and the auxiliary capillary reach tube 6 is connected to the back pressure chamber 9 of the on-off valve 8, so that when the solenoid valve SV is opened, the compressor 1
The capacity of the compressor 1 is set as the full capacity, and when the auxiliary capillary reach tube 6 is activated and the solenoid valve SV is closed, the capacity of the compressor 1 is set as the partial capacity,
And, by stopping the action of the auxiliary capillary reach tube 6 and opening/closing the solenoid valve SV,
A refrigeration system characterized in that the capacity of the compressor 1 is changed and the amount of pressure reduction by the capillary reach tubes 5 and 6 is adjusted according to the capacity of the compressor 1 at this time.