JP4115414B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus including means capable of introducing a gas refrigerant separated by a gas-liquid separator into an intermediate pressure portion of a compressor.

In general, a refrigeration apparatus including a compressor, a radiator, a decompression device, and a gas-liquid separator and having means capable of introducing the gas refrigerant separated by the gas-liquid separator into the intermediate pressure portion of the compressor is known. (See Patent Document 1). In this type of refrigeration apparatus, since the gas refrigerant separated by the gas-liquid separator is introduced into the intermediate pressure portion of the compressor in a gas state, the efficiency of the compressor can be improved. An effect is obtained.
JP 2003-106693 A

  By the way, in this kind of conventional refrigeration apparatus, a heat absorption means including a heat absorber that selectively functions in different temperature zones may be provided during the refrigeration cycle.

  For example, when this is applied to a refrigerator having a refrigerator compartment or a freezer compartment, a heat absorber functioning as a refrigerator or a refrigerator is arranged in the refrigeration cycle, and the refrigerator is refrigerated using the function of any one of the heat absorbers. Alternatively, the refrigeration operation is performed. In this case, it is important to operate at a high efficiency without reducing the efficiency at any operation.

  Therefore, an object of the present invention is to enable high-efficiency operation without reducing the efficiency in any temperature zone when heat absorption means that selectively function in different temperature zones is provided in the refrigeration cycle. It is to provide a refrigeration apparatus.

To achieve the above object, the present invention includes a first-stage compressing section and the second-stage compressing section, a compressor having an intermediate cooler between the first-stage compressing section and the second-stage compressing section, a radiator A decompressor , a gas-liquid separator , and a means capable of introducing a gas refrigerant separated by the gas-liquid separator and having a supercritical pressure between the intermediate cooler and the two-stage compression unit of the compressor ; , a low pressure side circuit for circulating the separated liquid refrigerant in the gas-liquid separator, a heat absorbing means which function in selected distinct temperature zone in the low pressure side circuit, the field to work the endothermic device with high temperature zone if, comprising a prohibiting means for prohibiting the introduction to between the intermediate cooler and the second-stage compressing section of the compressor of the gas refrigerant separated in the gas-liquid separator, the heat absorbing means mutually different temperature zones It has a plurality of functioning heat sinks, each of the heat sinks functions selectively, and cool air that has passed through the heat sinks Further, it is characterized in that means for guiding to a chamber controlled in a corresponding temperature zone is provided.

  In this case, the prohibiting means may be constituted by an on-off valve. In addition, the heat absorption means includes a plurality of heat absorbers that function in different temperature zones, each of the heat absorbers selectively functions, and the cold air that has passed through the heat absorber is controlled in a corresponding temperature zone. Means for guiding may be provided. Each of the heat absorbers may be installed in a room controlled in a corresponding temperature zone. The heat absorption means includes one heat absorber that selectively functions in different temperature zones, and the cool air that has passed through the heat absorber is selectively guided to a plurality of chambers that are controlled in different temperature zones through switching dampers. May be provided. The heat absorber may be installed in a chamber controlled in a low temperature zone. In all cases, a refrigerant whose high pressure side becomes supercritical pressure during operation may be enclosed.

  In the present invention, the heat absorption means that selectively function in different temperature zones is provided in the low-pressure circuit that circulates the liquid refrigerant, and when this heat absorption means functions in the high temperature zone, it is separated by the gas-liquid separator. Since the prohibiting means for prohibiting the introduction of the gas refrigerant to the intermediate pressure portion of the compressor is provided, high-efficiency operation is possible in each temperature range.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a refrigerant circuit diagram showing an embodiment of the present invention. The refrigeration apparatus 30 includes a compressor 1, a radiator 2, a first expansion valve (decompression apparatus) 3, and a gas-liquid separator 4 in this order. The refrigerant circuit from the compressor 1 through the radiator 2 to the inlet of the first expansion valve 3 constitutes a high-pressure side circuit. The compressor 1 is a two-stage compressor, includes a first-stage compressor 1A and a two-stage compressor 1B, and includes an intermediate cooler 1C between the first-stage compressor 1A and the two-stage compressor 1B. . 8 is a check valve. The refrigeration apparatus 30 includes means 5 that can introduce 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 part is between the intermediate cooler 1C and the two-stage compression part 1B. The compressor 1 here is not limited to a two-stage compressor. For example, if the compressor 1 is a one-stage compressor, the introduction means 5 may return to the intermediate pressure section of the first-stage compressor. That's fine. The introduction means 5 includes a gas pipe 6 and an opening / closing valve 91 provided in the gas pipe 6. Therefore, the opening / closing of the on-off valve 91 starts or stops the introduction of the gas refrigerant into the intermediate pressure portion.

  Further, the refrigeration apparatus 30 is provided with a low-pressure side circuit 9 for circulating the liquid refrigerant separated by the gas-liquid separator 4, and the low-pressure side circuit 9 selectively absorbs heat that functions in different temperature zones. Means 10 are provided. The heat absorbing means 10 includes a second expansion valve 11 and one heat absorber 14. By controlling the valve opening degree of the second expansion valve 11, the evaporation pressure in one heat absorber 14 is controlled. If the evaporating pressure here increases, the evaporating temperature in the heat absorber 14 becomes higher, and the refrigeration operation is performed. Moreover, if the evaporation pressure here falls, the evaporation temperature in the heat absorber 14 will become low, and it will become a freezing operation. The refrigerant that has passed through the heat absorber 14 is returned to the suction portion of the compressor 1 through the check valve 8.

  In this embodiment, it comprises a means 23 that selectively guides the cold air that has passed through the heat absorber 14 to a plurality of chambers (the refrigerator compartment 21 and the freezer compartment 22) that are controlled to different temperature zones. The means 23 includes a blower duct 24 and a switching damper 25, and a controller 26 that switches between refrigeration and freezing operation is connected to the switching damper 25. The controller 26 is also connected to the expansion valves 3 and 11 and the on-off valve 91. For example, when the load on the freezer compartment 22 increases, the switching damper 25 is brought down to the position shown in the figure, and the cool air is supplied to the freezer compartment 22. Lead to (freezing operation). During this refrigeration operation, the on-off valve 91 is opened, and the gas refrigerant separated by the gas-liquid separator 4 is introduced into the intermediate pressure portion of the compressor 1 as indicated by a broken line arrow. Moreover, when the load of the refrigerator compartment 21 increases, the switching damper 25 is brought down to a position opposite to the illustrated position, and the cold air is guided to the refrigerator compartment 21 (refrigeration operation). During this refrigeration operation, the on-off valve 91 is closed and the introduction of the gas refrigerant to the intermediate pressure portion of the compressor 1 is prohibited. The on-off valve 91 constitutes prohibiting means.

  In the refrigerant circuit described above, a refrigerant in which the high pressure side becomes a supercritical pressure during operation, for example, when the outside air temperature becomes 30 ° C. or higher in summer or when the load becomes large, for example, Carbon refrigerant is enclosed. Other examples of the refrigerant that is operated at a supercritical pressure in the high-pressure side circuit include ethylene, diborane, ethane, nitrogen oxide, and the like.

  In the above configuration, even if the gas refrigerant separated by the gas-liquid separator 4 is circulated to the low-pressure circuit 9, it cannot be used for cooling, and is returned to the suction of the first-stage compression unit 1A. This reduces the efficiency of the refrigeration cycle.

  Therefore, although the gas refrigerant is introduced into the intermediate pressure portion of the compressor 1, in the present embodiment, the gas refrigerant is compressed during the refrigeration operation in a low temperature zone based on the control by the controller 26 described above. While being introduced into the intermediate pressure portion of the machine 1, the introduction of the gas refrigerant to the intermediate pressure portion is prohibited during refrigeration operation in a high temperature zone.

  FIG. 2 is a ph diagram showing a two-stage compression and two-stage expansion cycle when a gas refrigerant is introduced into the first intermediate pressure portion X of the compressor 1 regardless of whether the operation is refrigeration or refrigeration.

  In FIG. 2, a cycle indicated by a solid line is formed during the freezing operation (freezing at around −26 ° C.). (1) is the suction of the first-stage compression unit 1A, (2) is the discharge of the first-stage compression unit 1A, (3) is the outlet of the intercooler 1C, and the suction of the two-stage compression unit 1B, (4 ) Is the discharge of the two-stage compression section 1A. The refrigerant discharged from the compressor 1 circulates through the radiator 2 and is cooled. (5) is an inlet of the first expansion valve 3, and (6) is an outlet of the first expansion valve 3. In this state, a gas / liquid two-phase mixture is formed.

  The ratio of gas to 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. And the gas refrigerant isolate | separated here is introduce | transduced between the intermediate pressure parts of the compressor 1, ie, the intermediate cooler 1C, and the two-stage compression part 1B. (21) is the outlet of the gas-liquid separator 4, and the refrigerant that has passed through this 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 in the low-pressure side circuit 9. (7) is the outlet of the gas-liquid separator 4, the inlet of the second expansion valve 11, (8) is the outlet of the second expansion valve 11, and (22) is the outlet of the heat absorber 14. The liquid refrigerant that has entered the heat absorber 14 evaporates and absorbs heat. (1) is the suction of the first stage compression unit 1A.

  On the other hand, the cycle shown with a broken line is formed at the time of refrigeration operation (refrigeration -5 degreeC vicinity). That is, (9) suction of the first stage compression unit 1A, (10) discharge of the first stage compression unit 1A, (11) outlet of the intermediate cooler 1C, suction of the second stage compression unit 1B, (12) two stage compression (5) Inlet of the first expansion valve 3, (13) Outlet of the first expansion valve 3, (14) Outlet of the gas-liquid separator 4, and inlet of the second expansion valve 11, (15 The state changes in the order of :) the outlet of the second expansion valve 11, and (9) the suction of the first stage compression unit 1A.

  By the way, referring to FIG. 2, the pressure (13) at the outlet of the first expansion valve 3 in the broken line cycle (during refrigeration operation) is the same as that of the first expansion valve 3 in the solid line cycle (during refrigeration operation). Compared to the outlet pressure (6), it is considerably higher. When the pressure at the outlet of the first expansion valve 3 increases, the gas content in the refrigerant before entering the gas-liquid separator 4 decreases. 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). It is. According to this, a considerable amount of gas refrigerant is introduced into the intermediate pressure part of the compressor 1 during the solid line cycle (refrigeration operation), but is introduced during the broken line cycle (refrigeration operation). The amount of gas refrigerant to be used becomes small.

  That is, during the refrigeration operation, the refrigerant amount of the gas introduced into the intermediate pressure portion of the compressor 1 increases, and the efficiency of the refrigeration cycle can be improved by the amount that does not circulate the gas component that does not contribute to cooling to the low-pressure circuit 9. it can. In particular, in this configuration, since the carbon dioxide refrigerant is sealed in the refrigerant circuit, the ratio of gas and liquid separated by the gas-liquid separator 4 is larger than that of the chlorofluorocarbon refrigerant. By introducing this gas component into the intermediate pressure part of the compressor 1, higher efficiency can be improved. On the other hand, during the refrigeration operation in a high temperature zone, the amount of gas refrigerant generated (L3) itself that is introduced into the intermediate pressure portion of the compressor 1 is reduced. Even so, for example, the compression efficiency of the compressor 1 cannot be improved so much only by complicating the piping configuration and the like.

  In the present embodiment, the gas refrigerant is introduced into the intermediate pressure portion of the compressor 1 only during a more effective refrigeration operation, while the gas refrigerant is introduced into the intermediate pressure portion during a refrigeration operation in a high temperature zone. Since the configuration is prohibited, a variable cycle is realized with a simple piping configuration and simple control, and the efficiency of the compressor 1 is improved.

  In the present embodiment, all of the heat absorbing means 10 that selectively function in different temperature zones, that is, the second expansion valve 11 and the heat absorber 14 are provided in the low-pressure side circuit 9. Even when the operation is performed or the refrigeration operation is performed, it is possible to perform an extremely efficient operation without reducing the efficiency.

  FIG. 3 shows an application example to a refrigerator.

  The refrigerator 40 includes a refrigeration room 41 in the upper stage and a freezing room 42 in the lower stage. An interior partition wall 43 is provided at the back of the freezer compartment 42, and the above-described heat absorber 14 is installed in the air passage 44 partitioned by the interior partition wall 43. A first switching damper 45 is disposed at the inlet A of the air passage 44, and the first switching damper 45 is located between a position (broken line position) for closing the inlet A of the air path 44 and a position (solid line position) for opening. Be switched between. Further, when the back side air passage 46 is formed in the back wall 47 of the refrigerator 40 and the first switching damper 45 is switched to the position of the broken line, the entrance of the air passage 44 is connected via the back side air passage 46. A communicates with the refrigerator compartment 41. 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 (broken line position) and opens ( The second switching damper 49 closes the opening 51 of the intermediate partition wall 50 at this solid line position.

  In the above configuration, during the refrigeration operation, the compressor 1 is turned on, the fan 48 is turned on, the on-off valve 91 is opened, and the dampers 45 and 49 are switched to the solid line positions. As a result, the air in the freezer compartment 42 circulates through the heat absorber 14 and is supplied to the freezer compartment 42. During the refrigeration operation, the on-off valve 91 is closed and the dampers 45 and 49 are switched to the broken line positions. As a result, the air in the refrigerator compartment 41 enters the air passage 44 via the back air passage 46, circulates through the heat absorber 14, and is supplied to the refrigerator compartment 41.

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

  FIG. 5 shows the configuration of another refrigerant circuit.

  In this configuration, when compared with FIG. 1, the configuration of the heat absorbing means 10 is different. The heat absorption means 10 includes a three-way valve 11, a first capillary tube 12, a refrigeration heat absorber 57 provided in series with the first capillary tube 12, and a second capillary tube 13 provided in parallel with these. And a refrigeration heat absorber 58 provided in series with the second capillary tube 13. 59 is a check valve. When the refrigerant flows through the first capillary tube 12 by switching the three-way valve 11, the flow rate flowing through one heat absorber 14 increases, and the refrigeration operation is performed. Further, when the refrigerant flows through the second capillary tube 13, the flow rate flowing through one heat absorber 14 is reduced, and the refrigeration operation is performed.

  FIG. 6 shows an application example to a refrigerator.

  The refrigerator 40 includes a refrigeration room 41 in the upper stage and a freezing room 42 in the lower stage. And the inner partition walls 61 and 62 are provided in the inner part of each chamber 41 and 42, respectively, and in the air path 44 partitioned by this inner partition wall 61 and 62, the heat absorber 57, 58 and fans 63 and 64 are installed. 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, the refrigerant flows through one of the heat absorbers 57 and 58, and the fans 62 and 63 corresponding thereto are driven.

  FIG. 7 shows another configuration. Compared with FIG. 6, the configuration of the heat absorbing means 10 is different. In the heat absorbing means 10, motor valves 65 and 66 are connected in series to the capillary tubes 12 and 13, while a three-way valve is omitted. In this configuration, the motor-operated valves 65 and 66 are turned on or off in accordance with the thermo-on and thermo-off of the refrigeration operation and the freezing operation, and the refrigerant is selectively allowed to flow through one of the heat absorbers 57 and 58, and correspondingly. The fans 62 and 63 are driven. In these embodiments, substantially the same operation and effect can be obtained.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this, A various change implementation is possible. In the above embodiment, the prohibiting means is configured by the on-off valve 91, but is not limited thereto. For example, during the refrigeration operation, a gas component is introduced into the intermediate pressure portion of the compressor 1, and during the refrigeration operation, As long as introduction can be prohibited, a circuit configuration formed by combining check valves and the like may be used. In the above embodiment, the carbon dioxide refrigerant is enclosed in the refrigerant circuit, but the present invention is not limited to this, and it can be applied to other refrigerant-filled refrigerants. Nor. Furthermore, the introduction means 5 only needs to be able to introduce a gas component into the intermediate pressure portion of the compressor 1 in accordance with the operation status, and the specific configuration and the introduction position thereof are arbitrary.

It is a refrigerant circuit figure showing one embodiment of the refrigerating device concerning the present invention. It is an enthalpy and pressure diagram of a refrigeration cycle. It is a figure which shows the example of application to a refrigerator. It is a figure which shows the example of application to a refrigerator. It is a refrigerant circuit diagram which shows another embodiment. It is a figure which shows the example of application to a refrigerator. It is a figure which shows the example of application to a refrigerator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Radiator 3 Pressure reducing device 4 Gas-liquid separator 5 Introduction means 6 Gas pipe 10 Heat absorption means 14 Heat absorber 21 Refrigeration room 22 Freezing room 25 Switching damper 30 Refrigerating device 91 Opening and closing valve 91

Claims (5)

And a first-stage compressing section and the second-stage compressing section, a compressor having an intermediate cooler between the first-stage compressing section and the second-stage compressing section, a radiator, a pressure reducing device, a gas-liquid separator, separated by the gas-liquid separator, a unit can be introduced between the intermediate cooler and the second-stage compressing section of the compressor of the gas refrigerant that reaches a supercritical pressure, the liquid separated by the gas-liquid separator a low pressure side circuit for circulating a refrigerant, and a heat absorbing means which function in selected distinct temperature zone in the low pressure side circuit, if to function this endothermic device at a high temperature zone, separated by the gas-liquid separator comprising a prohibiting means for prohibiting the introduction to between the intermediate cooler and the second-stage compressing section of the compressor of the gas refrigerant,
The heat absorption means includes a plurality of heat absorbers that function in different temperature zones, each of the heat absorbers selectively functions, and the cool air that has passed through the heat absorber is guided to a chamber that is controlled to a corresponding temperature zone. A refrigeration apparatus comprising:   2. The refrigeration apparatus according to claim 1, wherein the prohibiting means includes an on-off valve.   2. The refrigeration apparatus according to claim 1, wherein the heat absorber is installed in a room controlled in a corresponding temperature zone.   The heat absorption means includes one heat absorber that selectively functions in different temperature zones, and the cool air that has passed through the heat absorber is selectively guided to a plurality of chambers that are controlled in different temperature zones through switching dampers. The refrigeration apparatus according to any one of claims 1 to 3, further comprising:   The refrigerating apparatus according to claim 4, wherein the heat absorber is installed in a chamber controlled in a low temperature zone.

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