JPH0210063A - Device for refrigerating cycle - Google Patents

Abstract

PURPOSE:To make it possible to operate a refrigerating cycle which has a plurality of evaporation temperatures with a high energy consumption efficiency by controlling the coolant flowing in a flow channel switching channel and providing a flow channel switch device which switches flow channel to the direction in which either one of a second evaporator or evaporator in refrigerating cycle and the suction side of a compressor on a low stage side are in communication. CONSTITUTION:When a refrigerating chamber and cold storage chamber are both cooled, two-way solenoid valves 13 and 5 are changed over to opening and an one-way solenoid valve 14 to closing by the instruction of a control section 16. Liquid coolant of low pressure which is reduced in its pressure by a pressure reducing device 7 for refrigeration is supplied to an evaporator 8 for refrigeration, and liquid coolant of intermediate pressure which is reduced in its pressure by a pressure reducing device 11 for cold storage is supplied to an evaporator 10. With this arrangement the evaporator 8 for refrigeration evaporates at evaporation temperature which responds to the low pressure coolant and the evaporator 10 for cold storage evaporates at evaporation temperature which responds to the intermediate pressure. By the way the coolant of intermediate pressure that evaporates in the evaporator 10 for cold storage is sucked into a second compressor section 4 and the coolant of low pressure that evaporates in the evaporator 8 for refrigeration is sucked into a first compressor section 3. Consequently an efficient operation is achieved because evaporation is made at most suitable temperature for refrigeration and cold storage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a refrigeration cycle device constituting a refrigerator-freezer, an air conditioner, etc.

(Prior art) Conventionally, in refrigerator-freezers (refrigeration cycle equipment), the eighth
As shown in the figure, a 1-case, 1-cylinder type compressor a is equipped with a condenser, a capillary tube (decompression device) C1
Using a refrigeration cycle in which evaporators d for refrigerating and freezing are successively connected, cold air generated in the evaporators d is sent to a freezing compartment and a refrigerator compartment by switching dampers (not shown) or the like. Incidentally, FIG. 9 shows a Mollier diagram of the refrigeration cycle.

(Problem to be solved by the invention) However, such a refrigeration cycle that achieves freezing and refrigeration with one evaporator a operates in accordance with the evaporation temperature of refrigeration, so the evaporation temperature suitable for refrigeration (higher temperature than refrigeration) is Regardless of the presence of the evaporator d, the evaporation temperature of the evaporator d is lowered. For this reason, there is a considerable amount of energy
energy consumption efficiency) was poor.

This invention was made with attention to these circumstances,
The objective is to provide a refrigeration cycle device capable of operating a refrigeration cycle with a plurality of evaporation temperatures at a high EER.

[Configuration of the Invention (Means for Solving Problems)] In order to achieve the above object, the refrigeration cycle device of the present invention has a lower stage compressor section and a lower stage compressor section connected in series. A compressor configured with a high-stage compressor section is provided, and refrigeration cycle equipment constituting a refrigeration cycle is connected to this compressor, and between the condenser and evaporator of this refrigeration cycle equipment, A second evaporator is provided between the suction side of the stage side compressor section, and a flow path switching path is connected in communication between the outlet side of the second evaporator and the outlet side of the evaporator of the refrigeration cycle. , further controlling the refrigerant flowing through this flow switching path,
A flow path switching valve is provided to switch the flow path in a direction in which either one of the second evaporator and the evaporator of the refrigeration cycle communicates with the suction side of the lower stage compressor section.

(Function) According to the refrigeration cycle device of the present invention, as a first function, by switching the flow path switching valve, in one refrigeration cycle circuit, the intermediate pressure refrigerant is circulated through the second evaporator, and the low pressure refrigerant is circulated through the second evaporator. constitutes a cycle that circulates through the evaporator of the refrigeration cycle. As a result, the evaporator of the refrigeration cycle evaporates independently at the optimum evaporation temperature corresponding to the low-pressure refrigerant, and the second evaporator evaporates at the optimum evaporation temperature corresponding to the intermediate-pressure refrigerant.

In addition, as a second effect, by switching the flow path switching valve, 1
In one refrigeration cycle circuit, the evaporator of the refrigeration cycle, a low-stage compressor section, a high-stage compressor section, a two-stage compression cycle that circulates through the evaporator, or a second evaporator, a low-stage compressor section, A two-stage compression cycle that circulates through the high-stage compressor section and the evaporator is configured, so that the evaporators each having a different operating temperature can be independently evaporated with a small compressor input.

(Example) The present invention will be described below based on a first example shown in FIGS. 1 to 5. FIG. 1 shows a refrigeration cycle circuit (refrigeration cycle device) of a refrigerator to which the present invention is applied, and 1 is, for example, a rotary compressor.

The rotary compressor 1 includes a rotary first compressor section 3 (corresponding to a low-stage compressor section) and a second compressor section 4 (corresponding to a high-stage compressor section) in a sealed case 2. It has a structure in which they are installed in series.

Specifically, the first compressor section 3 is provided with a main bearing and an intermediate partition plate so as to sandwich a cylinder (not shown), and rollers and blades are provided in the space surrounded by the cylinder, main bearing, and intermediate partition plate. The established structure is used. In addition, the second compressor section 4 is provided with a cylinder superimposed on this intermediate partition plate, and similarly to the first compressor section 3, a sub-bearing is provided to sandwich this cylinder, and this cylinder and the A structure is used in which a gap and a plate are provided in a space surrounded by a partition plate and a sub-bearing.

The discharge part of the first compressor part 3 and the second compressor part 4
The refrigerant and the suction section are connected in series through a communication channel 5 formed of through holes, so that the refrigerant can be compressed in two stages through the communication channel 5. Although not shown, each roller of the first and second compressor sections 3 and 4 is directly connected to an electric motor section (consisting of a stator and a rotor) via a shaft, and is controlled by an inverter circuit. The first and second compressor sections 3.
It has a structure that can drive 4 at the same time.

Between the suction pipe 3a of the first compressor section 3, the second compressor section 4, and the discharge pipe 4a, a condenser 6, a pressure reducing device 7 for refrigeration (low temperature) consisting of a capillary tube, and a refrigeration (low temperature) evaporators 8 (all of which are refrigeration cycle equipment) are connected in sequence to form a refrigeration cycle.

On the other hand, reference numeral 9 denotes a bypass path which is connected to a midway portion of the communication flow path 5 and a refrigerant pipe portion between the condenser 6 and the pressure reducing device 7. In this bypass passage 9, there is provided an evaporator 10 for refrigeration (high temperature) that has a different operating temperature from the previous evaporator 8.
(corresponding to a second evaporator) or a decompression device 11 for refrigeration (high temperature) consisting of a capillary tube. Further, on the outlet side of the evaporator 8 for freezing and the evaporator 10 for refrigeration, a flow path switching path is provided so as to bypass between them.
2 are connected in series. Then, this flow path switching path 12
, the bypass path section from the connection part of flow path switching path 12 to the connecting flow path 5, and the flow path switching path 12. Electromagnetic three-way valves 13 and 14.1 are installed in the refrigerant pipe section from the outlet of the evaporator 8 to the connection of the flow path switching path 12, respectively.
5 (corresponding to a flow path switching valve) is installed. and,
These electromagnetic two-way valves 13, 14, and 15 are connected to a control section 16 (consisting of a microcomputer and its peripheral circuits), and are configured to switch the flow paths according to commands from the control section 16.

Specifically, the control unit 16 is configured to switch the electromagnetic three-way valves 13 and 15 to "open" as the first one and to "close" the remaining two-way electromagnetic valve 14, depending on the cooling effect, and to switch the two-way electromagnetic valve 14 as the second one. valve 13
．． 14 to "close" and the remaining electromagnetic three-way valve 15 to "open," and thirdly, the electromagnetic two-way valve 13.15 to "close" and the remaining electromagnetic two-way valve 14 to "open." It is set. Then, by switching the first flow path, the refrigerant coming out of the evaporator 8 for freezing is sucked into the first compressor section 3, and the refrigerant coming out of the evaporator 10 for refrigeration is drawn into the first compressor part 3, which is in the middle of two-stage compression. Independent parallel evaporation circuits for each evaporation temperature are configured to cause the evaporation temperature to be sucked into the compressor section 4 of the evaporation system. Further, by switching the second flow path, a two-stage compression cycle for refrigeration is configured in which only the refrigerant coming out of the evaporator 8 for refrigeration is circulated through the first compressor section 3 and the second compressor section 4. I have to. Furthermore, by the third flow path switching, only the refrigerant coming out of the evaporator 10 for refrigeration is circulated through the flow path switching path 12, the first compressor section 3, and the second compressor section 4. A two-stage compression cycle is configured. Incidentally, when the refrigeration cycle operation is stopped, all the electromagnetic three-way valves 13 to 15 are "closed".

Next, the operation of the refrigeration cycle circuit of the refrigerator-freezer configured as described above will be explained.

When cooling both the freezer compartment and the refrigerator compartment, first, the two-way electromagnetic valves 13 and 15 are opened by a command from the control unit 16.
Then, the electromagnetic two-way valve 14 is switched to "closed". After that, the electric motor section of the rotary compressor is energized, and the first
Then, the second compressor section 3.4 is driven. As a result, as shown in FIG. 3, the suction pipe 3a of the first compressor section 3
The refrigerant sucked from the refrigerant is compressed by the first compressor section 3 and then compressed again by the second compressor section 4 (two-stage compression). At the same time, refrigerant is sucked in from the bypass path 9, and is compressed in the second compressor section 4 together with the compressed refrigerant discharged from the first compressor section 3. Then, the compressed refrigerant discharged from the discharge pipe 4a of the second compressor section 4 is 1
It is condensed in two condensers 6. Then, the low pressure liquid refrigerant whose pressure is reduced by the refrigeration pressure reduction device 7 is supplied to the refrigeration evaporator 8, and the intermediate pressure liquid refrigerant whose pressure is reduced by the refrigeration pressure reduction device 11 is supplied to the refrigeration evaporator. The water is supplied to the container 10.

As a result, as shown in the Mollier diagram shown in Figure 2,
The evaporator 8 for freezing evaporates at an evaporation temperature that corresponds to the low-pressure refrigerant, and the evaporator 10 for refrigeration evaporates at an evaporation temperature that corresponds to the intermediate pressure. Note that the intermediate pressure refrigerant evaporated in the refrigeration evaporator 10 is sucked into the second compressor section 4, and the low pressure refrigerant evaporated in the refrigeration evaporator 8 is sucked into the first compressor section 3. It will be done.

Therefore, it is possible to evaporate at the optimum evaporation temperature for freezing and refrigeration, resulting in efficient operation.・.

On the other hand, when cooling only the freezer compartment, the three-way electromagnetic valves 13 and 14 are switched to "closed" and the three-way electromagnetic valve 5 is switched to "open" according to a command from the control unit 16. From this state, the rotary compressor 1 begins to operate in the same manner as described above. Then, as shown in FIG.
stage compression). Then, the two-stage compressed refrigerant condensed in the condenser 6 is supplied only to the refrigeration evaporator 8 through the refrigeration pressure reducing device 7.

However, since the evaporator 8 evaporates at the optimum evaporation temperature for refrigeration in a two-stage compression cycle that uses the entire refrigeration cycle, the load on the low refrigerant compressor 1 is reduced accordingly, resulting in a high EER.

On the other hand, when cooling only the refrigerator compartment, the two-way electromagnetic valve 1315 is switched to "closed" and the three-way electromagnetic valve 14 is switched to "open" according to a command from the control unit 16. From this state, the rotary compressor 1 begins to operate in the same manner as described above. Then, as shown in FIG. 5, the refrigerant is sucked only from the suction pipe 3a of the first compressor section 3.
The first compressor section 3 and the second compressor section 4 perform compression (two-stage compression). The two-stage compressed refrigerant condensed in the condenser 6 is then introduced into the refrigeration pressure reducing device 11,
It is supplied only to the evaporator 10 for refrigeration. Next, the refrigerant is evaporated in the evaporator 10, and then sucked into the first compressor section 3 again through the flow path switching valve 12.

However, in a two-stage compression cycle that uses the entire refrigeration cycle circuit, the evaporator] 0 is evaporated at the optimum evaporation temperature for refrigeration, so the load on the refrigeration compressor 1 is reduced, just as in the case of freezing earlier. , shows a high EER.

In this way, the refrigeration cycle can be operated with high efficiency with excellent EER.

Note that the present invention is not limited to the first embodiment, and may be implemented as a second embodiment shown in FIG. 6 or a third embodiment shown in FIG. 7.

That is, in the second embodiment, instead of the two-way electromagnetic valves 13 to 15, three-way electromagnetic valves 20 and 21 are used to switch the flow paths. Specifically, electromagnetic three-way valves 20 and 21 are interposed at the connection portion of the flow path switching path 12. According to a command from the control unit 16, the electromagnetic three-way valve 2o 21 is set to "H" when cooling the freezer compartment and the refrigerator compartment.
The remaining electromagnetic three-way valve 21 is switched in the arrow direction indicated by "Ll", and when cooling only the freezer compartment, the electromagnetic three-way valve 20 is switched in the arrow direction indicated by "H3", and the remaining electromagnetic three-way valve 21 is switched in the arrow direction indicated by "H3". It is switched in the direction of the arrow indicated by "Ll". When further cooling only the refrigerator compartment, the electromagnetic three-way valve 20 moves in the direction of the arrow indicated by "H2", and the remaining electromagnetic three-way valve 2
1 is switched in the direction of the arrow shown by "L3", and in the first embodiment, the refrigerant flows shown in FIGS. 3 to 5 are formed. In addition, when the operation is stopped, the electromagnetic three-way valve 20 moves in the direction of the arrow indicated by "H3",
The remaining electromagnetic three-way valve 21 is switched in the direction of the arrow indicated by "L3".

Further, in the third embodiment, the high temperature and high pressure liquid refrigerant in the condenser 6 is prevented from flowing into the evaporator 8 for freezing and the evaporator 10 for refrigeration while the rotary compressor 1 is stopped. .

Specifically, a refrigerant relief passage 25 is connected in communication between the outlet side of the condenser 6 and the suction side of the rotary compressor 1, for example, an outlet portion of the bypass passage 9, and the artificial side of this refrigerant relief passage 25 is connected. An electromagnetic three-way valve 26 is provided in the section. Then, using the control unit 16, the electromagnetic three-way valve 26 is switched in the direction of the arrow indicated by "S" when the rotary compressor 1 is operating, and as indicated by "S2" when the rotary compressor 1 is stopped. I try to switch in the direction of the arrow. In addition, a pressure reducing device 27 composed of a capillary tube is interposed in the refrigerant relief passage 25, and when the rotary compressor 1 stops, the electromagnetic three-way valve 26 is set to "Sl".
The high-temperature, high-pressure refrigerant that is about to flow out from the condenser 6 is returned to the suction side of the second compressor section 4 through the refrigerant relief passage 25 (evaporator 8.10). temperature rise). Note that this refrigerant is used in the pressure reducing device 2.
The pressure is reduced at 7. Of course, it is not the electromagnetic three-way valve 26,
Other valves may be used to switch the flow paths.

In addition, in the third embodiment, an evaporation pressure reducing device 28 made of a capillary tube is connected in communication between the outlet side of the evaporator 8 for freezing and the outlet side of the evaporator 10 for refrigeration. In addition, when the cooling operation of one of the freezing and refrigerating compartments described in the previous embodiment is stopped, the high temperature refrigerant flowing from the high pressure side is depressurized by the pressure reducing device 28 and evaporated. (Preventing unnecessary temperature rises in the freezer and refrigerator compartments).

However, in the second and third embodiments, the same parts as in the first embodiment are given the same reference numerals, and their explanations are omitted.

In the embodiments described above, the present invention is applied to a refrigerator-freezer, but it may also be applied to a refrigeration cycle device other than a refrigerator-freezer that has a plurality of evaporators with different operating temperatures. Of course, a heat pump type refrigeration cycle device provided with a four-way valve may also be used.

[Effects of the Invention] As explained above, according to the present invention, the evaporator of the refrigeration cycle is set at the optimum evaporation temperature according to the low-pressure refrigerant, and the second evaporator is set at the optimum evaporation temperature according to the intermediate-pressure refrigerant. temperature, each can be evaporated. Moreover, in addition to that,
A two-stage compression cycle that circulates through the evaporator, low-stage compressor section, high-stage compressor section, and evaporator of the refrigeration cycle, or the second
It is also possible to configure a two-stage compression cycle that circulates through the evaporator, the low-stage compressor section, the high-stage compressor section, and the evaporator, and evaporate each evaporator with a small input of the compressor.

Therefore, a refrigeration cycle having multiple evaporation temperatures can be operated with high EER.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the invention,
Figure 1 is a configuration diagram showing the main part of the refrigeration cycle circuit, Figure 2 is its Mollier diagram, Figures 3 to 5 are diagrams showing the flow of different refrigerants, and Figure 6 is the second diagram of the present invention. FIG. 7 is a block diagram showing a main part of the refrigeration cycle circuit of the third embodiment of the present invention. FIG. 8 is a block diagram showing the main part of a refrigeration cycle circuit of a conventional refrigerator-freezer FIG. 9 is a Mollier diagram thereof. 1...Lower Recon Breather (compressor), 3.1st
compressor section (low stage compressor section), 4... second compressor section (high stage compressor section), 5... connecting flow path, 6.7.8
... Condenser, refrigeration pressure reducing device, refrigeration evaporator (refrigeration cycle equipment), 9...ノ (Inokusuji, ]0...
Evaporator for refrigeration (second evaporator), 11... Pressure reducing device for refrigeration, 12... Channel switching path, 13-15... Solenoid two-way valve (channel switching valve), 16 ...control section. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A compressor comprising a low-stage compressor section and a high-stage compressor section that communicates in series with the low-stage compressor section, and refrigeration cycle equipment that is connected to this compressor and configures a refrigeration cycle. and a second evaporator provided in communication between the condenser and the evaporator of the refrigeration cycle equipment and the suction side of the high-stage compressor section, and a second evaporator of the second evaporator. A flow switching path is connected in communication between the outlet side and the exit side of the evaporator of the refrigeration cycle, and the refrigerant flowing through the flow switching path is controlled to control the second evaporator and the refrigeration cycle. A refrigeration cycle device comprising a flow path switching valve that switches a flow path in a direction in which one of the evaporators and the suction side of the low-stage compressor section communicate with each other.