KR20060043489A - Refrigerator - Google Patents

Abstract

Means (5) comprising a compressor (1), a radiator (2), a pressure reducing device (3), and a gas-liquid separator (4), and capable of introducing the gas refrigerant separated by the gas-liquid separator (4) to the intermediate pressure portion of the compressor (5). And a low pressure side circuit (9) for circulating the liquid refrigerant separated by the gas-liquid separator, and the low pressure side circuit (9) is provided with endothermic means (10) which selectively functions at different temperature zones. When the heat absorbing means 10 functions at a high temperature range, the gas refrigerant separated by the gas-liquid separator 4 is blocked from being introduced into the intermediate pressure portion of the compressor 1, or the second pressure is lower than the intermediate pressure portion. Gas refrigerant is introduced into the middle.

Compressor, radiator, pressure reducing device, gas-liquid separator, low pressure side circuit

Description

Refrigeration unit {REFRIGERATOR}

1 is a refrigerant circuit diagram showing a first embodiment of a refrigerating device according to the present invention.

2 is an enthalpy pressure diagram of a refrigeration cycle.

3 is a diagram showing an application example to a refrigerator of the first embodiment;

4 shows an application example to a refrigerator.

Fig. 5 is a refrigerant circuit diagram showing a modification of the first embodiment.

Fig. 6 shows an example of application to a refrigerator.

7 shows an application example to a refrigerator.

8 is a refrigerant circuit diagram showing a second embodiment of a refrigerating device according to the present invention.

9 is an enthalpy pressure diagram of a refrigeration cycle.

FIG. 10 is a diagram showing an application example to the refrigerator of the second embodiment, and FIG.

FIG. 11 is a view showing an example of application to a refrigerator; FIG.

FIG. 12 is a refrigerant circuit diagram showing a modification of the second embodiment; FIG.

FIG. 13 is a view showing an example of application to a refrigerator; FIG.

FIG. 14 is a view showing an example of application to a refrigerator; FIG.

<Explanation of symbols for the main parts of the drawings>

1: compressor

2: radiator

4: gas-liquid separator

6: gas pipe

9: low voltage side circuit

10: endothermic means

21: refrigerator

22: freezer

26: controller

91: on-off valve

The present invention relates to a refrigerating device having means capable of introducing a gas refrigerant separated in a gas-liquid separator into the intermediate pressure portion of the compressor.

In general, a refrigerating device is known which includes a compressor, a radiator, a decompression device, and a gas-liquid separator, and a means capable of introducing the gas refrigerant separated in the gas-liquid separator into the intermediate pressure portion of the compressor (Japanese Patent Laid-Open No. 2003-106693). Publication). In this type of refrigerating device, since the gas refrigerant separated by the gas-liquid separator is introduced into the intermediate pressure portion of the compressor as it is in the gas state, the efficiency of the compressor can be improved.

By the way, in the conventional refrigeration apparatus of this kind, there exists a case where the heat absorption means containing the heat absorber which functions selectively in another temperature range during a refrigeration cycle.

For example, when this is applied to a refrigerator having a refrigerating compartment or a freezing compartment, an endotherm functioning as a refrigerating or freezing unit is arranged during a refrigerating cycle, and refrigeration or freezing operation is performed using the function of any one endotherm. In this case, it is important to operate at high efficiency without any loss of efficiency in any operation.

Accordingly, an object of the present invention is to provide a refrigerating device that enables high-efficiency operation without degrading its efficiency in any temperature range when endothermic means selectively serving at different temperature ranges is provided in the refrigeration cycle. .

In order to achieve the above object, the present invention includes a compressor, a radiator, a pressure reducing device, a gas-liquid separator, and a means capable of introducing the gas refrigerant separated in the gas-liquid separator into the intermediate pressure portion of the compressor. A low pressure side circuit for circulating the separated liquid refrigerant is provided, and the low pressure side circuit is provided with endothermic means, which selectively functions at different temperature zones, and is separated from the gas-liquid separator when the endothermic means functions at a high temperature zone. And a gas refrigerant blocking and introduction switching means for interrupting the introduction of the gas refrigerant into the intermediate pressure portion of the compressor or for introducing the gas refrigerant into another intermediate pressure portion on the lower pressure side than the intermediate pressure portion of the compressor.

A part of the gas refrigerant blocking and introducing switching means may be constituted by an on / off valve. The other part of the gas refrigerant blocking and introducing switching means may be constituted by a three-way valve and a branch gas pipe.

The heat absorbing means may be provided with a plurality of heat absorbers functioning at different temperature zones, and each heat absorber may selectively include means for guiding the cold air passing through the heat absorber into a chamber controlled at a corresponding temperature. Each of the heat absorbers may be provided in a chamber controlled according to a corresponding temperature. The heat absorbing means may be provided with one heat absorber selectively functioning at different temperature zones, and may be provided with means for selectively guiding the cold air passing through the heat absorber through a switching damper into a plurality of chambers controlled at different temperatures. The heat absorber may be installed in a chamber controlled at a low temperature. In all cases, the refrigerant at which the high pressure side becomes a supercritical pressure during operation may be sealed.

The gas refrigerant separated from the gas-liquid separator by the three-way valve and the branch gas pipe may be introduced into either the first intermediate pressure portion of the compressor or the second intermediate pressure portion closer to the lower pressure suction side than the first intermediate pressure portion. When the heat absorbing means is configured to be introduced at a low temperature range, the gas refrigerant separated by the gas-liquid separator is introduced into the first intermediate pressure portion of the compressor. When the heat absorbing means is operated at a high temperature range, the gas refrigerant is supplied to the compressor. Is introduced into the second intermediate pressure section.

In this case, the heat absorbing means includes a plurality of heat absorbers functioning at different temperature zones, and each heat absorber selectively functions to guide the cold air passing through the heat absorber into a chamber controlled at a corresponding temperature. You may be provided. Moreover, the said heat absorber may be provided in the chamber respectively controlled by the corresponding temperature.

Moreover, even if the said heat absorbing means is equipped with one heat absorber selectively functioning in a different temperature range, and is equipped with the means which selectively guides the cold air via this heat absorber through the switching damper into several chambers controlled by different temperature, respectively. good. In this case, the heat absorber may be provided in a chamber controlled at a low temperature. In all of the above cases, a coolant such as a carbon dioxide refrigerant whose high pressure side becomes a supercritical pressure during operation may be sealed.

In the present invention, the endothermic means, which selectively functions at different temperature zones, is provided in the low pressure side circuit for circulating the liquid refrigerant, and when the endothermic means functions at the high temperature zone, the intermediate of the compressor of the gas refrigerant separated from the gas-liquid separator is provided. Since the gas refrigerant blocking means for blocking the introduction to the pressure portion is provided, high efficiency operation is possible in each temperature range.

In the present invention, the endothermic means, which selectively functions at different temperature zones, is provided in the low-pressure side circuit for circulating the liquid refrigerant, and when the endothermic means functions at the low temperature zone, the gas refrigerant separated from the gas-liquid separator is provided. When introduced into the first intermediate pressure portion and functioning at a high temperature range, the gas refrigerant introduction means for introducing the gas refrigerant into the second intermediate pressure portion of the compressor is provided, so that high efficiency operation is possible in each temperature range.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

1 is a refrigerant circuit diagram showing an embodiment of the present invention. This refrigeration apparatus 30 is comprised by providing the compressor 1, the radiator 2, the 1st expansion valve (pressure reducing apparatus) 3, and the gas-liquid separator 4 in order. The refrigerant circuit from the compressor 1 to the inlet of the first expansion valve 3 via the radiator 2 constitutes the high pressure side circuit. The compressor 1 is a two-stage compressor, which includes a first stage compression unit 1A and a second stage compression unit 1B, and is intermediate between the first stage compression unit 1A and the second stage compression unit 1B. It has a cooler 1C. Reference numeral 8 is a check valve. The refrigeration apparatus 30 further includes a means 5 capable of introducing the gas refrigerant separated by the gas-liquid separator 4 into the intermediate pressure portion of the compressor 1. In this configuration, the intermediate pressure portion is between the intermediate cooler 1C and the two stage compression portion 1B. The compressor 1 here is not limited to a two-stage compressor. If the compressor 1 is a one-stage compressor, for example, the introduction means 5 may be returned to the intermediate pressure portion of the one-stage compressor. This introduction means 5 is comprised from the gas pipe 6 and the opening-closing valve 91 provided in this gas pipe 6. Therefore, introduction of the gas refrigerant into the intermediate pressure portion is started or stopped by opening and closing the on-off valve 91.

In addition, the refrigeration apparatus 30 is provided with a low pressure side circuit 9 for circulating the liquid refrigerant separated from the gas-liquid separator 4, and the low pressure side circuit 9 selectively absorbs heat at different temperature ranges. Means 10 are provided. This heat absorbing means 10 is comprised with the 2nd expansion valve 11 and one heat absorber 14, and is comprised. By controlling the valve opening degree of this 2nd expansion valve 11, the evaporation pressure in one heat absorber 14 is controlled. When the evaporation pressure rises here, the evaporation temperature in the heat absorber 14 becomes high and it is refrigerated operation. Moreover, when the evaporation pressure here falls, the evaporation temperature in the heat absorber 14 will become low, and it will become a refrigeration operation. The refrigerant passing through the heat absorber 14 is returned to the suction part of the compressor 1 via the check valve 8.

In this embodiment, it is comprised by the means 23 which selectively guides the cold air which passed through the heat absorber 14 to several chambers (refrigerating chamber 21 and freezing chamber 22) controlled by different temperature, respectively. This means 23 includes a blower duct 24 and a switching damper 25. The switching damper 25 is connected to a controller 26 for switching refrigeration and freezing operations.

The controller 26 is also connected to the expansion valves 3 and 11 and the opening / closing valve 91. For example, when the load of the freezing chamber 22 is increased, the switching damper 25 is brought down to the position shown. The cold air is guided to the freezing chamber 22 (freezing operation). During this refrigeration operation, the open / close valve 91 is opened to introduce the gas refrigerant separated from the gas-liquid separator 4 into the intermediate pressure portion of the compressor 1 as indicated by the broken arrow. In addition, when the load of the refrigerating chamber 21 is increased, the switching damper 25 is dropped to a position opposite to the illustrated position to guide the cold air into the refrigerating chamber 21 (refrigeration operation). During this refrigeration operation, the on-off valve 91 is closed to block the introduction of the gas refrigerant into the intermediate pressure portion of the compressor 1. The on-off valve 91 constitutes a gas refrigerant blocking means.

In the coolant circuit described above, a coolant, for example a carbon dioxide coolant, in which the high pressure side becomes a supercritical pressure during operation under conditions such as when the outside air temperature is 30 ° C. or higher in summer or when the load is large is enclosed. In addition, as a refrigerant | coolant in which a high pressure side circuit operates in supercritical pressure, ethylene, diborane, an ethane, nitrogen oxide, etc. are mentioned, for example.

In the above configuration, the gas refrigerant separated from the gas-liquid separator 4 cannot be used for cooling even if it is circulated through the low pressure side circuit 9, and returning it to the suction of the first stage compression section 1A is a Decreases the efficiency.

Thus, although the gas refrigerant is introduced into the intermediate pressure portion of the compressor 1, in the present embodiment, the gas refrigerant is supplied to the compressor 1 during the refrigeration operation having a low temperature range based on the control by the controller 26 described above. While introducing into the intermediate pressure portion, the introduction of gas refrigerant into the intermediate pressure portion is blocked during refrigeration operation with a high temperature range.

FIG. 2 is a ph diagram showing a two-stage compressed two-stage expansion cycle in the case where gas refrigerant is introduced into the first intermediate pressure section X of the compressor 1 regardless of refrigeration or freezing operations.

In Fig. 2, a cycle indicated by a solid line is formed during the freezing operation (near freezing at -26 ° C). (1) is the suction of the 1st stage compression unit 1A, (2) the discharge of the 1st stage compression unit 1A, (3) is the suction of the 2 stage compression unit 1B, (4) is the 2 stage compression unit Discharge of 1A. The refrigerant discharged from the compressor 1 is circulated through the radiator 2 and cooled. (5) is the inlet of the first expansion valve (3), (6) is the outlet of the first expansion valve (3), and in this state becomes a two-phase mixture of gas / liquid.

The ratio of gas and liquid here corresponds to the ratio between the length of the line segment of L1 (gas) and the length of the line segment of L2 (liquid). This refrigerant enters the gas-liquid separator 4 in the state of a two-phase mixture. Then, the separated gas refrigerant is introduced between the intermediate pressure portion of the compressor 1, that is, between the intermediate cooler 1C and the two-stage compression portion 1B. Denoted at 21 is an outlet of the gas-liquid separator 4, and the refrigerant passing therethrough reaches the suction of the two-stage compression section 1B of (3) and is compressed by the two-stage compression section 1B. On the other hand, the liquid refrigerant separated by the gas-liquid separator 4 circulates through the low pressure side circuit 9. 7 is an outlet of the gas-liquid separator 4, an inlet of the second expansion valve 11, 8 an outlet of the second expansion valve 11, and 22 an outlet of the heat absorber 14. The liquid refrigerant entering the heat absorber 14 evaporates to absorb heat. (1) is suction of the 1st stage compression part 1A.

On the other hand, in the refrigeration operation (near refrigeration-5 degreeC), the cycle shown by a broken line is formed. That is, (9) suction of one-stage compression unit 1A, (10) discharge of one-stage compression unit 1A, (11) suction of two-stage compression unit 1B, (12) two-stage compression unit 1B ), (5) the inlet of the first expansion valve (3), (13) the outlet of the first expansion valve (3), (14) the outlet of the gas-liquid separator (4), and the The state changes in the order of the inlet, (15) the outlet of the second expansion valve 11, and (9) the suction of the first stage compression section 1A.

By the way, referring to Fig. 2, the pressure 13 at the outlet of the first expansion valve 3 in the broken cycle (during refrigeration operation) is the value of the first expansion valve 3 in the solid cycle (during refrigeration operation). It is very high compared to the pressure 6 at the outlet. When the pressure at the outlet of the first expansion valve 3 is increased, the amount of gas in the refrigerant before entering the gas-liquid separator 4 is reduced. As described above, the ratio of gas and liquid at the inlet of the gas-liquid separator 4 corresponds to the ratio of L1 (gas) and L2 (liquid) or the ratio of L3 (gas) and L4 (liquid). According to this, a considerable amount of gas refrigerant is introduced into the intermediate pressure portion of the compressor 1 during the cycle of solid line (in freezing operation), but the amount of gas refrigerant introduced during the cycle of broken line (in refrigeration operation) becomes slightly.

That is, during the refrigeration operation, the amount of refrigerant of the gas introduced into the intermediate pressure portion of the compressor 1 increases, so that the efficiency of the refrigeration cycle can be improved as long as the gas component not contributing to the cooling is circulated to the low pressure circuit 9. In particular, in this configuration, since the carbon dioxide refrigerant is enclosed in the refrigerant circuit, in the ratio of the gas and the liquid separated by the gas-liquid separator 4, the gas content is larger than that of the pron-based refrigerant, and the gas content is increased in the compressor 1. By introducing into the intermediate pressure section, higher efficiency can be achieved. On the other hand, since the generation amount L3 of the gas refrigerant introduced into the intermediate pressure portion of the compressor 1 is small at the time of refrigerating operation having a high temperature range, even if the gas refrigerant is introduced therein, for example, the piping configuration, etc. Compared with the complexity of the refrigeration cycle extrusion efficiency can not be improved as much.

In the present embodiment, the gas refrigerant is introduced into the intermediate pressure portion of the compressor 1 only in a refrigeration operation having a higher effect, while the gas refrigerant is prevented from being introduced into the intermediate pressure portion in the refrigeration operation having a high temperature range. In addition, the piping configuration is simple, and the variable cycle is realized by simple control, and the efficiency of the refrigeration cycle can be improved.

In addition, in this embodiment, since all the heat absorbing means 10 which selectively function in a different temperature range, ie, the 2nd expansion valve 11 and the heat absorber 14, are provided in the low pressure side circuit 9, the example For example, even when refrigeration operation is performed or when refrigeration operation is performed, it is possible to perform a very high efficiency operation without degrading its efficiency.

3 shows an application example to a refrigerator.

This refrigerator 40 is provided with the refrigerator compartment 41 in the upper end, and the freezer compartment 42 in the lower end. The inner compartment of the freezer compartment 42 is provided with an internal compartment wall 43, and the heat absorber 14 described above is provided in the air passage 44 partitioned by the internal compartment wall 43. A first switching damper 45 is disposed at the inlet A of the air passage 44, and the first switching damper 45 has a position (dashed position) for closing the inlet A of the air passage 44, It is switched between the opening position (solid line position). In addition, when the back side air path 46 is formed in the back wall 47 of the refrigerator 40, and the 1st switching damper 45 is switched to a broken line position, the air path 44 through this back side air path 46 is carried out. The inlet A of) and the refrigerator compartment 41 communicate. In addition, a fan 48 and a second switching damper 49 are disposed at the outlet B of the air passage 44, and the second switching damper 49 closes the outlet B of the air passage 44. The switch is switched between the position (broken position) and the opening position (solid line position), in which the second switching damper 49 blocks the opening 51 of the intermediate partition wall 50.

In the above configuration, the compressor 1 is turned ON during the freezing operation, the fan 48 is turned on, the opening / closing valve 91 is opened, and the respective dampers 45 and 49 are switched to the solid line position. As a result, air in the freezing chamber 42 circulates through the heat absorber 14 and is supplied to the freezing chamber 42. The on-off valve 91 is closed during the refrigerating operation, and the respective dampers 45 and 49 are switched to the broken line position. As a result, the air in the refrigerating chamber 41 enters the air passage 44 via the rear side air passage 46, circulates through the heat absorber 14, and is supplied to the refrigerating chamber 41.

4 shows another configuration. When compared with FIG. 3, the damper structure in the entrance and exit of the air path 44 is different. The damper at the inlet A is composed of two dampers 145A, 145B, and the damper at the outlet B is composed of two dampers 149A, 149B. Even in this configuration, the same effects can be obtained.

5 shows a configuration of a refrigerant circuit of the first embodiment.

In this structure, when compared with FIG. 1, the structure of the heat absorbing means 10 is different. The heat absorbing means (10) includes a three-way valve (11), a first capillary tube (12), a cold heat absorber (57) provided in series with the first capillary tube (12), and The second capillary tube 13 provided in parallel and the refrigeration heat absorber 58 provided in series with the 2nd capillary tube 13 are comprised. Reference numeral 59 is a check valve. When the refrigerant flows through the first capillary tube 12 by switching of the three-way valve 11, the flow rate flowing through one heat absorber 14 is increased to perform the refrigerating operation. In addition, when the refrigerant flows through the second capillary tube 13, the flow rate flowing through one endotherm 14 is reduced, and the freezing operation is performed.

6 shows an application example to a refrigerator.

This refrigerator 40 is provided with the refrigerator compartment 41 in the upper end, and the freezer compartment 42 in the lower end. Inner compartment partitions 61 and 62 are provided at the inner side portions of the chambers 41 and 42, respectively, and in the air passage 44 partitioned by the compartment partition walls 61 and 62, the heat absorber 57 described above. And 58) and fans 63 and 64 are provided. In this configuration, the three-way valve 11 is switched in accordance with the thermo-on and the thermo-off of the refrigeration operation and the freezing operation, and the refrigerant flows to either of the heat absorbers 57 and 58, and the fan corresponding thereto. (62, 63) are driven.

7 shows another configuration. When compared with FIG. 6, the structure of the heat absorbing means 10 is different. In the endothermic means 10, the three-way valve is omitted, while the electric valves 65 and 66 are connected in series to the capillary tubes 12 and 13. In this configuration, the electric valves 65 and 66 are turned on or off in accordance with the thermo-on and thermo-off of the refrigerating operation and the freezing operation, and the refrigerant is selectively flowed through either of the heat absorbers 57 and 58. And the fans 62 and 63 corresponding thereto are driven. In these embodiments, substantially the same effects can be obtained.

Although this invention was demonstrated based on the said embodiment, this invention is not limited to this, A various change practice is possible. In the above embodiment, the gas refrigerant blocking means is constituted by the on-off valve 91, but the present invention is not limited thereto. For example, the gaseous component is introduced into the intermediate pressure portion of the compressor 1 during the refrigeration operation. As long as the introduction can be interrupted, a circuit structure formed by combining a check valve or the like may be used. In addition, although the carbon dioxide refrigerant is encapsulated in the refrigerant circuit in the above embodiment, it is a matter of course that the present invention can also be applied to an encapsulated proton refrigerant or the like. Moreover, the introduction means 5 should just be able to introduce | transduce a gas powder into the intermediate | middle pressure part of the compressor 1 according to the operation situation, The concrete structure and the introduction position are arbitrary.

In the above embodiment, the gas coolant to the intermediate pressure section is cut off on the premise that the amount L3 of gas refrigerant introduced into the intermediate pressure section of the compressor 1 is small during the refrigeration operation having a high temperature range. . However, when the generation amount L3 of the gas coolant is not small, the refrigeration efficiency can be further improved by setting the gas coolant not contributing to cooling to the low pressure circuit side.

Hereinafter, the embodiment which can aim at the efficiency of a refrigeration cycle by introducing a gas refrigerant into the compressor 1 at the time of refrigeration operation is demonstrated.

8 is a refrigerant circuit diagram showing a second embodiment of the present invention. This refrigeration apparatus 130 has the same configuration except the refrigerant circuit of the first embodiment and a part of the configuration. Hereinafter, the explanation will be given based on other configurations, and the same or corresponding components will be denoted by the same reference numerals and detailed description thereof will be omitted.

The refrigerating device 130 is replaced with an on-off valve 91 which is a gas refrigerant blocking means provided in the first embodiment, and the gas refrigerant separated by the gas-liquid separator 4 is replaced with the first intermediate pressure portion X of the compressor 1. ) Or means 105 which can be introduced into any one of the second intermediate pressure portions Y closer to the lower pressure suction side than the first intermediate pressure portion X. In this structure, the 1st intermediate | middle pressure part X is between 1 C of intermediate | middle coolers and the 2nd stage compression part 1B, and the 2nd intermediate | middle pressure part Y is in the middle of 1A compression part 1A. The compressor 1 here is not limited to a two stage compressor.

The introduction means 105 is composed of a gas pipe 6, a three-way valve 81 provided in the gas pipe 6, and two branch gas pipes 82 and 83 branched from the three-way valve 81. One branch gas pipe 82 is connected to the first intermediate pressure section X, and the other branch gas pipe 83 is connected to the second intermediate pressure section Y. FIG. The three-way valve 81 and the branch gas pipe 83 constitute gas refrigerant introduction means here. Therefore, when the gas pipe 6 and the branch gas pipe 82 communicate with each other by the switching of the three-way valve 81, the gas refrigerant is introduced into the first intermediate pressure section X as indicated by the broken arrow, and the gas pipe 6 and When the branch gas pipe 83 communicates, the gas refrigerant is introduced into the second intermediate pressure portion Y. Here, the three-way valve 81 is not limited to an electronic type, and a differential pressure drive type or the like is also considered.

The controller 26 is connected to the compressor 1, the expansion valves 3 and 11, and the three-way valve 81. For example, when the load of the freezing chamber 22 is increased, the second expansion valve 11 ), The valve opening degree is widened, the flow rate flowing through one endotherm 14 is increased, and the switching damper 25 is knocked down to the position shown to guide the cold air into the freezing chamber 22 (freezing operation). During this refrigeration operation, the gas pipe 6 and the branch gas pipe 82 communicate with each other by the switching of the three-way valve 81, and the gas refrigerant separated from the gas-liquid separator 4 is transferred to the first intermediate pressure section as indicated by the broken arrow. Introduced by (X). In addition, when the load of the refrigerating chamber 21 is increased, the switching damper 25 is dropped to a position opposite to the illustrated position to guide the cold air into the refrigerating chamber 21 (refrigeration operation). During this refrigeration operation, the gas pipe 6 and the branch gas pipe 83 communicate with each other by switching the three-way valve 81, and the gas refrigerant is introduced into the second intermediate pressure portion Y.

As in the first embodiment, in the above-described refrigerant circuit, the high pressure side becomes a supercritical pressure during operation, for example, when the outside air temperature is 30 ° C or higher in summer, or when the load is large, for example, Carbon dioxide refrigerant is sealed. Examples of the coolant operated at the supercritical pressure in the high-pressure side circuit include ethylene, diborane, ethane and nitrogen oxide.

In the above configuration, the gas refrigerant separated from the gas-liquid separator 4 cannot be used for cooling even if it is circulated through the low pressure side circuit 9, and returning it to the suction port of the first stage compression section 1A is a It lowers the efficiency. Thus, the gas refrigerant is introduced into the intermediate pressure portion of the compressor 1. However, as described in the first embodiment, if the amount of generated gas refrigerant L3 is small, even if it is circulated to the low pressure side circuit 9, the efficiency of the refrigerating cycle is not significantly affected. In other words, simply introducing such a small amount of gas refrigerant into the middle of the compressor cannot improve the efficiency of the refrigeration cycle. Therefore, in the present embodiment, the gas refrigerant is introduced into the first intermediate pressure section X of the compressor 1 during the refrigeration operation having a low temperature range based on the control by the controller 26 described above, while the temperature range is increased. At the time of high refrigeration operation | movement, the efficiency is further improved by introducing into the 2nd intermediate | middle pressure part Y which is closer to the low pressure suction side of the compressor 1 than this 1st intermediate | middle pressure part X.

9 shows a gas refrigerant introduced into the first intermediate pressure section X of the compressor 1 during a refrigeration operation having a low temperature zone, and a compressor 1 of the compressor 1 more than this first intermediate pressure section X during a refrigeration operation with a high temperature range. It is a ph diagram showing the two stage compression two stage expansion cycle in the case where it is introduced into the second intermediate pressure portion Y near the low pressure suction side. Here, FIG. 2 and FIG. 9 which show a ph diagram in the case where gas refrigerant is introduced into the first intermediate pressure part X of the compressor 1 regardless of refrigeration or freezing operation are compared.

In Fig. 2 and Fig. 9, cycles indicated by solid lines are formed during freezing operation (near freezing at −26 ° C.). (1) is the suction of the 1st stage compression unit 1A, (2) the discharge of the 1st stage compression unit 1A, (3) is the suction of the 2 stage compression unit 1B, and (4) is the 2 stage compression unit Discharge of 1B. The refrigerant discharged from the compressor 1 is circulated through the radiator 2 and cooled. (5) is the inlet of the first expansion valve (3), (6) is the outlet of the first expansion valve (3), and in this state becomes a two-phase mixture of gas / liquid.

The ratio of gas and liquid here corresponds to the ratio of the length of the line segment of L1 (gas) and the length of the line segment of L2 (liquid). This refrigerant enters the gas-liquid separator 4 in the state of a two-phase mixture. Then, the separated gas refrigerant is introduced between the intermediate pressure portion of the compressor 1, that is, between the intermediate cooler 1C and the two-stage compression portion 1B. 21 is an outlet of the gas-liquid separator 4, and the refrigerant passing therethrough reaches the suction of the first intermediate pressure section X, that is, the two-stage compression section 1B of (3), and the two-stage compression section 1B. Is compressed). On the other hand, the liquid refrigerant separated by the gas-liquid separator 4 circulates through the low pressure side circuit 9. 7 is an outlet of the gas-liquid separator 4, an inlet of the second expansion valve 11, 8 an outlet of the second expansion valve 11, and 22 an outlet of the heat absorber 14. The liquid refrigerant entering the heat absorber 14 evaporates to absorb heat. (1) is suction of the 1st stage compression part 1A.

On the other hand, in the refrigeration operation (near refrigeration-5 degreeC), the cycle shown by a broken line is formed, respectively. That is, in Fig. 9, (9) the suction of the first stage compression unit 1A, (11) the second intermediate pressure unit Y, that is, the intermediate portion of the first stage compression unit 1A, (12) the one stage compression unit ( Discharge of 1A, the inlet of the intermediate | middle cooler 1C, (13) the outlet of the intermediate | middle cooler 1C, the suction of the two stage compression part 1B, (14) the discharge of the two stage compression part 1B, ( 5) the inlet of the first expansion valve 3, (15) the outlet of the first expansion valve 3, (16) the outlet of the gas-liquid separator 4, the inlet of the second expansion valve 11, (17) The state changes in order of the outlet of the 2nd expansion valve 11, and the suction of the 1st stage compression part 1A of (9).

In Fig. 2, since the gas refrigerant is introduced into the first intermediate pressure section X of the compressor 1, it is as follows. That is, (9) the suction of the first stage compression unit 1A, (10) the discharge of the first stage compression unit 1A, (11) the first intermediate pressure unit X, that is, the outlet of the intermediate cooler 1C, 2 Intake of the stage compression section 1B, (12) Discharge of the two stage compression section 1B, (5) Inlet of the first expansion valve 3, (13) Outlet of the first expansion valve 3, (14 ) Is the outlet of the gas-liquid separator 4, the inlet of the second expansion valve 11, (15) the outlet of the second expansion valve 11, and (9) the suction of the first stage compression section 1A. Is changed.

2 and 9, gas refrigerant is introduced into the first intermediate pressure section X of the compressor 1 during the refrigeration operation having a low temperature range as described above. Therefore, during this refrigeration operation, a cycle of substantially the same solid line is formed in each drawing.

On the other hand, in the refrigerating operation with a high temperature zone, the gas refrigerant is introduced into the first intermediate pressure portion X of the compressor 1 in FIG. 2, whereas in FIG. 9, the gas refrigerant is lower than the first intermediate pressure portion X. It is introduced into the adjacent second intermediate pressure portion Y. The pressure of the second intermediate pressure portion Y is lower than the pressure of the first intermediate pressure portion X, and therefore, when the gas refrigerant is introduced into the second intermediate pressure portion Y having a low pressure, the first intermediate pressure portion X The pressure at the outlet of the first expansion valve 3 can be lowered as compared with the case of introducing the furnace gas refrigerant.

That is, in this refrigeration operation, in the cycle shown by the broken line, the pressure of the line segments (Fig. 9) of L5 and L6 is lower than the pressure of the line segments (Fig. 2) of L3 and L4. When the pressure at the outlet of the first expansion valve 3 decreases, the amount of gas in the refrigerant before entering the gas-liquid separator 4 increases. This can be seen from the fact that the line segment L5 is longer than the line segment L3. As described above, the ratio of gas and liquid at the inlet of the gas-liquid separator 4 corresponds to the ratio of L5 (gas) and L6 (liquid) in FIG. 9, and L3 (gas) and L4 in FIG. 2. This is because it corresponds to the ratio of (liquid). Therefore, in FIG. 9, the amount of refrigerant of the gas introduced into the intermediate pressure portion of the compressor 1 becomes larger than that of FIG. 2, and cannot be ignored. The efficiency of the cycle can be improved. In particular, since the carbon dioxide refrigerant is enclosed in the refrigerant circuit in this configuration, in the ratio of gas and liquid separated by the gas-liquid separator 4, the amount of gas is increased as compared to that of the pron-based refrigerant, By introducing into the intermediate pressure section, higher efficiency can be achieved.

In addition, in this embodiment, since all the heat absorbing means 10 which selectively function in a different temperature range, ie, the 2nd expansion valve 11 and the heat absorber 14, are provided in the low pressure side circuit 9, for example, Even when the refrigeration operation is performed or when the refrigeration operation is performed, it is possible to perform a very high efficiency operation without degrading its efficiency.

In addition, by attaching the gas refrigerant blocking means 105 of the first embodiment and the gas refrigerant introducing means 105 of the second embodiment so as to be connected in series, for example, a refrigeration cycle attributable to the gas refrigerant generation amount during the refrigeration operation. Both means may be switched in accordance with the reduction in efficiency. Specifically, the gas refrigerant blocking means 5 may be attached to the gas refrigerant discharge side of the gas-liquid separator 4, and the gas refrigerant introduction means 105 may be attached to the output side of the gas refrigerant blocking means 5.

The gas coolant introducing means 105 may be introduced into the first intermediate pressure portion of the compressor 1 or the second intermediate pressure portion closer to the suction side of the compressor 1 than the first intermediate pressure portion, depending on the operation situation. It is good and the specific structure and the introduction position are arbitrary.

10 to 14 show an example in which the present embodiment is adapted to a refrigerator, and corresponding to FIGS. 3 to 7 when the gas refrigerant blocking means 5 is switched to the gas refrigerant introducing means 105. FIG. to be. Since each operation in the refrigerator is the same as the operation described with reference to FIGS. 3 to 7, the following description will be omitted.

As described above, the present invention introduces a gas refrigerant into the intermediate pressure portion of the compressor 1 during a more effective refrigeration operation, while introducing a gas refrigerant into the intermediate pressure portion during a refrigeration operation with a high temperature range. Since it is set as the structure which cuts off or introduces into the intermediate part of the lower pressure side more than the said intermediate | middle pressure part, it is a simple piping structure and a variable cycle is realized by simple control, and the refrigeration cycle efficiency can be improved.

The gas refrigerant blocking means disclosed in the above-described first embodiment and the gas refrigerant introducing means disclosed in the second embodiment may be used alone, respectively. For example, the gas-liquid separator (for example, as a gas refrigerant switching means having both functions) You may arrange | position it to the gas pipe 6 between 4) and the compressor 1. In this case, gas refrigerant blocking means is provided on the gas-liquid separator 4 side, and gas refrigerant introducing means is disposed between the gas refrigerant blocking means and the compressor 1. In the freezing operation, the gas refrigerant blocking means and the gas are introduced such that the gas refrigerant from the gas-liquid separator 4 passes through the gas refrigerant blocking means, and also passes through the gas refrigerant introducing means to be introduced into the first intermediate pressure section X of the compressor. The refrigerant introduction means is operated. In the refrigerating operation, for example, the gas refrigerant from the gas-liquid separator 4 is blocked by the gas refrigerant blocking means in accordance with a situation such as the amount of gas refrigerant at the outlet of the first expansion valve 3, or the like. The switching medium may be configured to be introduced into the gas refrigerant introduction unit through the gas refrigerant blocking unit and introduced to the second intermediate pressure unit Y of the compressor.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to this, A various change practice is possible. For example, although the carbon dioxide refrigerant is encapsulated in the refrigerant circuit in the above configuration, the present invention is not limited thereto, and of course, the present invention can also be applied to an encapsulated proton refrigerant or the like.

Claims (13)

A low pressure side circuit having a compressor, a radiator, a pressure reducing device, and a gas-liquid separator, having means for introducing gas refrigerant separated in the gas-liquid separator into the intermediate pressure portion of the compressor, and circulating the liquid refrigerant separated from the gas-liquid separator. The low pressure side circuit is provided with endotherm means which selectively function in another temperature range, and when this endotherm means functions in a high temperature range, the intermediate pressure part of the compressor of the gas refrigerant separated by the gas-liquid separator A refrigeration apparatus comprising a gas refrigerant blocking means for blocking the introduction to the gas. The refrigeration apparatus according to claim 1, wherein the gas refrigerant blocking means is constituted by an on / off valve. The heat sink according to claim 1, wherein the heat absorbing means has a plurality of heat absorbers functioning at different temperature zones, and each of the heat absorbers selectively functions to guide the cold air passing through the heat absorber into a chamber controlled to a corresponding temperature, respectively. Refrigeration apparatus comprising a. The refrigeration apparatus according to claim 3, wherein the heat absorbers are provided in chambers which are controlled at corresponding temperatures, respectively. The heat absorbing means according to claim 1, wherein the heat absorbing means is provided with one heat absorber selectively functioning at different temperature zones, and selectively directs the cold air passing through the heat absorber through a switching damper to a plurality of chambers controlled at different temperatures. A refrigeration apparatus comprising a means. The refrigeration apparatus according to claim 5, wherein the heat absorber is provided in a chamber controlled at a low temperature. The refrigeration apparatus according to claim 1, wherein a high pressure side encloses a refrigerant at which the high pressure side becomes a supercritical pressure during operation. A compressor, a radiator, a pressure reducing device, and a gas-liquid separator are provided, and the gas refrigerant separated by the gas-liquid separator is introduced into either the first intermediate pressure portion of the compressor or the second intermediate pressure portion closer to the lower pressure suction side than the first intermediate pressure portion. And a low pressure side circuit for circulating the liquid refrigerant separated from the gas-liquid separator, the low pressure side circuit being provided with endothermic means which selectively functions at different temperature zones, Gas function which introduces the gas refrigerant separated by the gas-liquid separator into the first intermediate pressure part of the compressor when operating in a bed, and introduces the gas refrigerant into the second intermediate pressure part of the compressor when operating in a high temperature range. A refrigeration apparatus comprising a refrigerant introduction means. The heat sink according to claim 8, wherein the heat absorbing means includes a plurality of heat absorbers functioning at different temperature zones, and each heat absorber selectively functions to guide the cold air passing through the heat absorber to the chambers controlled to the corresponding temperatures, respectively. Refrigeration apparatus comprising a. 10. The refrigeration apparatus according to claim 9, wherein the heat absorbers are provided in chambers respectively controlled at corresponding temperatures. 9. The heat absorbing means according to claim 8, wherein the heat absorbing means is provided with one heat absorber selectively functioning at different temperature zones, and selectively directs the cold air passing through the heat absorber through a switching damper to a plurality of chambers controlled at different temperatures. A refrigeration apparatus comprising a means. The refrigeration apparatus according to claim 11, wherein the heat absorber is provided in a chamber controlled at a low temperature. The refrigerating device according to claim 8, wherein the high pressure side encloses a refrigerant that becomes a supercritical pressure during operation.

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