WO2010041453A1

WO2010041453A1 - Refrigeration device

Info

Publication number: WO2010041453A1
Application number: PCT/JP2009/005246
Authority: WO
Inventors: 松岡慎也; 藤吉竜介; 田中修
Original assignee: ダイキン工業株式会社
Priority date: 2008-10-08
Filing date: 2009-10-08
Publication date: 2010-04-15
Also published as: JP2010112698A

Abstract

An air conditioning device provided with a refrigerant circuit for performing a supercritical refrigeration cycle by two-stage compression, wherein the air conditioning device is provided with an ice heat storage tank (2) which provides, without an increase in the amount of electric power consumption by a compressor, the air conditioning device with refrigeration ability close to the refrigeration ability of an air conditioning device using a current HFC-based refrigerant. The ice heat storage tank (2) stores therein water or ice as a heat storage medium and is provided with a heat storage heat exchanger (14) connected to a refrigerant circuit (10) and exchanging heat between the heat storage medium and the refrigerant in the refrigerant circuit (10). The ice heat storage tank (2) functioning as a heat dissipater when the heat storage heat exchanger (14) utilizes cold energy of the heat storage medium is provided between a low-stage compressor (11a) and a high-stage compressor (11b) of the air conditioning device (1).

Description

Refrigeration equipment

The present invention relates to a refrigeration apparatus including a refrigerant circuit that performs a supercritical refrigeration cycle.

Conventionally, a refrigeration apparatus including a refrigerant circuit that performs a supercritical refrigeration cycle using carbon dioxide as a refrigerant is known (see, for example, Patent Document 1). FIG. 26 is a diagram showing a supercritical refrigeration cycle in a conventional refrigeration apparatus on a Ph (pressure-enthalpy) diagram of carbon dioxide.

A refrigerant circuit of a conventional refrigeration apparatus is configured by a closed circuit in which a compression mechanism, a heat source side heat exchanger, an expansion valve, and a use side heat exchanger are connected in order. In the cooling operation of the refrigeration apparatus (air conditioner), the heat source side heat exchanger serves as a radiator, and the use side heat exchanger serves as an evaporator. Note that each of the heat source side heat exchanger and the use side heat exchanger is constituted by an air heat exchanger.

The high-pressure refrigerant compressed to the critical pressure (point e in FIG. 26) or higher by the compression mechanism is discharged from the compression mechanism. The high-pressure refrigerant discharged from the compression mechanism flows into the heat source side heat exchanger (point b in FIG. 26). The high-pressure refrigerant flowing into the heat source side heat exchanger flows out of the heat source side heat exchanger after radiating heat to the outside air (point c in FIG. 26). The high-pressure refrigerant that has flowed out of the heat-source-side heat exchanger is reduced in pressure by the expansion valve to become low-pressure refrigerant (point d in FIG. 26), and flows into the use-side heat exchanger. The low-pressure refrigerant that has flowed into the use side heat exchanger absorbs heat from the air in the use space and evaporates, and then flows out of the use side heat exchanger. The low-pressure refrigerant that has flowed out of the use-side heat exchanger is sucked into the compression mechanism (point a in FIG. 26), compressed to a critical pressure or higher, and then discharged as high-pressure refrigerant again. By repeating this operation, the cooling operation of the refrigeration apparatus is performed.

JP 2007-263383 A

By the way, in the cooling operation of the refrigeration apparatus using the current HFC-based refrigerant, for example, when the outside air temperature is about 30 ° C., the refrigerant outlet temperature of the heat source side heat exchanger is about 40 ° C. or so.

In the case of this refrigeration apparatus, since the high pressure of the refrigeration cycle is lower than the critical pressure, the HFC refrigerant discharged from the compressor and flowing into the heat source side heat exchanger has a temperature in the heat source side heat exchanger. Phase change occurs until the temperature drops to about 40 ° C., and latent heat is released.

On the other hand, for example, when carbon dioxide is used as the refrigerant of the refrigeration apparatus, the high pressure of the refrigeration cycle is equal to or higher than the critical pressure. Until it falls, carbon dioxide does not change phase. For this reason, carbon dioxide can only release sensible heat in the heat source side heat exchanger. Therefore, when the circulation amount of carbon dioxide and the HFC refrigerant is the same, the amount of heat released in the heat source side heat exchanger is smaller in carbon dioxide.

Therefore, in a refrigeration apparatus using carbon dioxide as a refrigerant, in order to bring the refrigeration capacity close to the refrigeration capacity of the HFC refrigerant, the heat exchanger is increased in size and the circulation amount of the refrigerant flowing through the refrigerant circuit is increased. Need to be increased. However, even if the circulation amount of the refrigerant is increased to obtain a refrigerating capacity equivalent to that of the HFC refrigerant, the power consumption of the compressor increases due to the increase of the refrigerant circulation amount, which is not preferable. .

The present invention has been made in view of such a point, and an object of the present invention is to provide a refrigeration apparatus equipped with a refrigerant circuit that performs a supercritical refrigeration cycle without reducing the refrigeration capacity of the compressor without increasing the power consumption of the compression mechanism. The refrigerating capacity of the refrigerating apparatus using the HFC-based refrigerant is approached.

The first invention is a refrigerant circuit (10) in which a compression mechanism (11), a heat source side heat exchanger (12), an expansion mechanism (15), and a use side heat exchanger (16) are connected to perform a supercritical refrigeration cycle. ) Is assumed.

And in the said freezing apparatus, while storing water or ice as a thermal storage medium, it is connected to the said refrigerant circuit (10), and the thermal storage heat exchanger (14 which exchanges heat between the thermal storage medium and the refrigerant | coolant of the said refrigerant circuit (10) ), And the heat storage heat exchanger (14) includes an ice heat storage tank (2) that serves as a radiator when using the cold energy of the heat storage medium.

The compression mechanism (11) includes a low-stage compressor (11a) and a high-stage compressor (11b), while the heat storage heat exchanger (14) includes the low-stage compressor (11a). ) And the higher stage compressor (11b).

In the first invention, the ice heat storage tank (2) is provided for the refrigeration apparatus that performs the supercritical refrigeration cycle. Using the cold heat of the ice generated in the ice heat storage tank (2), the heat storage heat exchanger (14) of the ice heat storage tank (2) serves as a radiator. Therefore, for example, the refrigerant in the refrigerant circuit (10) performing the supercritical refrigeration cycle dissipates heat in both the heat source side heat exchanger (12) and the heat storage heat exchanger (14).

In addition, by causing the compression mechanism (11) to perform two-stage compression, it is possible to suppress the amount of power consumption compared to the case of single-stage compression, and the compressor is discharged from the low-stage compressor (11a). By cooling the refrigerant with the heat storage heat exchanger (14), the amount of power consumption can be further reduced.

In other words, when the compression mechanism (11) for single-stage compression and the compression mechanism (11) of the first invention have the same power consumption, the refrigerating capacity of the refrigeration apparatus having the compression mechanism (11) of the first invention is large. It will be. That is, the refrigerating capacity can be increased without increasing the power consumption.

In a second aspect based on the first aspect, the heat storage heat exchanger (14) is a first heat storage connected between the low-stage compressor (11a) and the high-stage compressor (11b). A heat exchanger (14), further comprising a second heat storage heat exchanger (19) connected between the heat source side heat exchanger (12) of the refrigerant circuit (10) and the expansion mechanism (15). It is characterized by having.

In the second invention, by causing the compression mechanism (11) to perform the two-stage compression, the power consumption can be suppressed as compared with the case of the single-stage compression, and the low-stage compressor (11a) By cooling the refrigerant discharged from the first heat storage heat exchanger (14), the power consumption can be further suppressed. Moreover, the refrigerant radiated by the heat source side heat exchanger (12) can be further cooled by the second heat storage heat exchanger (19).

Here, for example, if the heat source side heat exchanger (12) is composed of an air heat exchanger, as described above, the refrigerant outlet temperature of the heat source side heat exchanger (12) is approximately 40 ° C., When the circulation amount of carbon dioxide and the HFC refrigerant is the same, the amount of heat released in the heat source side heat exchanger (12) is smaller in carbon dioxide.

That is, the refrigeration effect of the use side heat exchanger (16) in the refrigeration apparatus is smaller when carbon dioxide is used than when the HFC refrigerant is used. Here, the refrigeration effect is the difference between the so-called refrigerant outlet specific enthalpy (point a in FIG. 26) and the refrigerant inlet specific enthalpy (point d in FIG. 26) of the use side heat exchanger (16). .

When the second heat storage heat exchanger (19) is used, the temperature of the refrigerant flowing out from the heat source side heat exchanger (12) can be further lowered, and the refrigeration effect can be improved. Thereby, the circulation amount of the refrigerant in the refrigerant circuit (10) can be reduced by the amount that the refrigeration effect is improved, and the power consumption of the compression mechanism (11) is reduced.

From the above, by providing the first and second heat storage heat exchangers (14, 19), the refrigerating capacity can be increased without increasing the power consumption.

According to a third aspect of the present invention, in the first aspect, the refrigerant circuit (10) includes a cold heat operation using the cold heat of the ice heat storage tank (2) by using the heat storage heat exchanger (14) as a radiator, The heat storage heat exchanger (14) is used as an evaporator, and an ice storage tank (2) is provided with a switching mechanism (SV) that can be switched to a heat storage operation for storing cold energy.

In the third invention, by providing the switching mechanism (SV) in the refrigerant circuit (10), it is possible to cause the refrigeration apparatus to perform a cold energy use operation and a heat storage operation.

In the case of the heat storage operation, the switching mechanism (SV) is switched so that the heat storage heat exchanger (14) becomes an evaporator. Then, in the heat storage heat exchanger (14), water stored in the ice heat storage tank (2) is cooled by the refrigerant in the refrigerant circuit (10), and ice is generated from the water. In this way, the cold energy of the refrigerant can be stored.

On the other hand, in the case of the operation using cold energy, the switching mechanism (SV) is switched so that the heat storage heat exchanger (14) becomes a radiator. Then, the refrigerant | coolant which flows through the said refrigerant circuit (10) can be radiated using the ice produced | generated by the heat storage operation mentioned above.

According to a fourth aspect, in the third aspect, the refrigerant circuit (10) is configured to start the low-stage compressor (11a) or the high-stage compressor (11b) during the cold heat operation. It is characterized by being.

In the fourth aspect of the invention, only the low-stage side compressor (11a) or the high-stage side compressor (11b) is activated during the cold utilization operation. Then, the refrigerant discharged from the activated compressor dissipates heat in the heat storage heat exchanger (14), and after being depressurized to a predetermined pressure by the expansion mechanism (15), evaporates in the use side heat exchanger (16). . The refrigerant evaporated in the use side heat exchanger (16) is sucked into the activated compressor, is compressed, and is discharged from the compressor (11b) again.

The fifth invention is characterized in that, in the first invention, the refrigerant flowing through the refrigerant circuit (10) is carbon dioxide.

In the fifth invention, carbon dioxide is used as the refrigerant flowing through the refrigerant circuit (10). When this carbon dioxide is compared with the current HFC-based refrigerant, the latent heat increases and the refrigerant density increases as the saturation pressure decreases. Therefore, the capacity | capacitance at the time of the thermal storage driving | operation of the said freezing apparatus can be improved by using the said carbon dioxide.

According to the present invention, the refrigerant in the refrigerant circuit (10) performing the supercritical refrigeration cycle can be radiated to the ice of the heat storage heat exchanger (14). When the refrigerant dissipates heat to ice, the temperature of the refrigerant can be greatly reduced. The refrigeration capacity of the conventional refrigeration apparatus can be approached without increasing the power consumption of the compression mechanism (11).

Further, according to the present invention, the compression mechanism (11) performs two-stage compression, and the refrigerant discharged from the low-stage compressor (11a) is cooled by the heat storage heat exchanger (14). To the high-stage compressor (11b). Thus, when the compression mechanism (11) of the single-stage compression and the compression mechanism (11) of the second invention have the same power consumption, the first-stage compression mechanism (11) is more than the refrigeration apparatus having the single-stage compression mechanism (11). The refrigerating capacity of the refrigerating apparatus having the compression mechanism (11) of the first invention will be large. That is, the refrigerating capacity can be increased without increasing the power consumption.

As described above, by providing the heat storage heat exchanger (14), which is a heat dissipating means different from the heat source side heat exchanger (12), the refrigeration can be performed without increasing the power consumption of the compression mechanism (11). The refrigeration capacity of the apparatus can be brought close to the refrigeration capacity of a conventional refrigeration apparatus.

According to the second aspect of the invention, the compression mechanism (11) performs two-stage compression, and the refrigerant discharged from the low-stage compressor (11a) is transferred to the first heat storage heat exchanger (14 ). If it carries out like this, refrigerating capacity can be increased, without increasing power consumption similarly to 1st invention.

Also, by providing the second heat storage heat exchanger (19), the temperature of the refrigerant flowing out from the heat source side heat exchanger (12) can be further lowered, and the refrigeration effect can be improved. As a result, the amount of refrigerant circulating in the refrigerant circuit (10) can be reduced by an amount corresponding to the improved refrigeration effect, and the power consumption of the compression mechanism (11) can be reduced.

As described above, by providing the first and second heat storage heat exchangers (14, 19), which are heat dissipating means different from the heat source side heat exchanger (12), the power consumption of the compression mechanism (11) can be reduced. It is possible to approach the refrigeration capacity of the conventional refrigeration apparatus without increasing it.

According to the third aspect of the invention, for example, in the refrigeration apparatus, the heat storage operation is performed by using relatively inexpensive nighttime electric power, and the cold heat of the refrigerant is stored in the ice heat storage tank (2). . And the power consumption in the daytime can be suppressed by using the generated ice during the daytime cold energy utilization operation. That is, it is possible to make the peak power shift of the daytime power and to approach the refrigeration capacity of the conventional refrigeration apparatus without increasing the power consumption of the compression mechanism (11).

In addition, according to the fourth aspect of the invention, only the low-stage compressor (11a) or the high-stage compressor (11b) is activated during the cold utilization operation. If it carries out like this, the power consumption of the said compression mechanism (11) can be reduced compared with the case where both the said low stage side compressor (11a) and the said high stage side compressor (11b) are started.

According to the fifth aspect of the invention, by using carbon dioxide as the refrigerant flowing through the refrigerant circuit (10), the capacity of the refrigeration apparatus during heat storage operation can be increased compared to the current HFC refrigerant. Can do.

FIG. 1 is an overall view of an air conditioning apparatus (refrigeration apparatus) according to the present invention. FIG. 2 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 1 of the present invention. FIG. 3 is a refrigerant circuit diagram illustrating an operation during a heat storage operation according to the first embodiment. FIG. 4 is a refrigerant circuit diagram illustrating an operation at the time of cold energy utilization operation according to the first embodiment, FIG. 4 (A) illustrates a first cold energy utilization operation, and FIG. 4 (B) is a second cold energy utilization operation. Is shown. FIG. 5 is a diagram showing a refrigeration cycle performed by the refrigerant circuit according to the first embodiment on a Ph diagram. FIG. 6 is a refrigerant circuit diagram of an air-conditioning apparatus according to Modification 1 of Embodiment 1. FIG. 7 is a refrigerant circuit diagram illustrating an operation during a heat storage operation according to the first modification of the first embodiment. FIG. 8 is a refrigerant circuit diagram illustrating an operation at the time of cold utilization operation according to the first modification of the first embodiment. FIG. 9 is a diagram illustrating a refrigeration cycle performed by the refrigerant circuit according to the first modification of the first embodiment on a Ph diagram. FIG. 10 is a refrigerant circuit diagram of an air-conditioning apparatus according to Modification 2 of Embodiment 1. FIG. 11 is a refrigerant circuit diagram illustrating an operation during a heat storage operation according to the second modification of the first embodiment. FIG. 12 is a refrigerant circuit diagram illustrating an operation at the time of the cold energy use operation according to the second modification of the first embodiment. FIG. 13 is a diagram illustrating a refrigeration cycle performed by the refrigerant circuit according to the second modification of the first embodiment on a Ph diagram. FIG. 14 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 2 of the present invention. FIG. 15 is a refrigerant circuit diagram illustrating an operation during a heat storage operation according to the second embodiment. FIG. 16 is a refrigerant circuit diagram illustrating an operation during a cold energy utilization operation according to the second embodiment. FIG. 17 is a diagram illustrating a refrigeration cycle performed by the refrigerant circuit according to the second embodiment on a Ph diagram. FIG. 18 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 3 of the present invention. FIG. 19 is a refrigerant circuit diagram illustrating an operation during a heat storage operation according to the third embodiment. FIG. 20 is a refrigerant circuit diagram illustrating an operation at the time of the cold energy utilization operation according to the third embodiment. FIG. 21 is a diagram illustrating a refrigeration cycle performed by the refrigerant circuit according to the third embodiment on a Ph diagram. FIG. 22 is a refrigerant circuit diagram of an air-conditioning apparatus according to a modification of the third embodiment. FIG. 23 is a refrigerant circuit diagram illustrating an operation during a heat storage operation according to a modification of the third embodiment. FIG. 24 is a refrigerant circuit diagram illustrating an operation at the time of cold utilization operation according to a modification of the third embodiment. FIG. 25 is a diagram illustrating a refrigeration cycle performed by the refrigerant circuit according to the modification of the third embodiment on a Ph diagram. FIG. 26 is a diagram showing a refrigeration cycle performed by a conventional refrigerant circuit on a Ph diagram.

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

Embodiment 1 of the Invention
Embodiment 1
FIG. 1 is an overall view of an air conditioning apparatus (refrigeration apparatus) (1) according to a first embodiment. 2 is a refrigerant circuit diagram of the air conditioner (1) according to the first embodiment, FIG. 3 shows a refrigerant flow during a heat storage operation, and FIG. 4 shows a refrigerant flow during a cold heat operation. . FIG. 5 is a diagram showing a refrigeration cycle at the time of operation using cold energy on a Ph diagram of carbon dioxide.

The air conditioner (1) of Embodiment 1 includes an ice heat storage tank (2) and an outdoor unit (3) installed outdoors, and an indoor unit (4) installed indoors. And these apparatuses (2, 3, and 4) are mutually connected by connection piping, and the refrigerant circuit (10) shown in FIG. 2 is comprised. The refrigerant circuit (10) is filled with carbon dioxide (hereinafter referred to as refrigerant) as a refrigerant. The high pressure of the refrigerant circuit (10) is set to be higher than the critical pressure of carbon dioxide.

In addition, the air conditioner (1) is configured such that its operation can be switched between a heat storage operation and a cold energy operation. For example, in the air conditioner (1), by generating ice from the water in the ice storage tank (2) using the nighttime electricity during the heat storage operation and using the generated ice during the daytime cold energy operation, Power consumption during the daytime can be reduced. The heat storage operation and the cold energy utilization operation will be described later in detail.

The refrigerant circuit (10) includes a high stage compressor (11b), a low stage compressor (11a), an outdoor heat exchanger (heat source side heat exchanger) (12), and first and second expansion valves ( Expansion mechanism) (15b, 15c), pressure reducing valve (15a), indoor heat exchanger (use side heat exchanger) (16), supercooling heat exchanger (18), and heat storage heat exchanger (14) ing. Further, the refrigerant circuit (10) is provided with an on-off valve (switching mechanism) (SV) for switching the operation of the air conditioner (1) between the heat storage operation and the cold energy utilization operation.

The high-stage compressor (11b) and the low-stage compressor (11a) are both configured as a so-called hermetic type and constitute a compression mechanism (11). In addition, an inverter (not shown) is connected to each compressor (11a, 11b), and each compressor (11a, 11b) is configured to have a variable capacity by this inverter.

Both the outdoor heat exchanger (12) and the indoor heat exchanger (16) are cross fin type fin-and-tube heat exchangers. An outdoor fan (not shown) is provided in the vicinity of the outdoor heat exchanger (12), and an indoor fan (not shown) is provided in the vicinity of the indoor heat exchanger (16). The outdoor heat exchanger (12) is configured to exchange heat between the outdoor air sent from the outdoor fan and the refrigerant flowing through the outdoor heat exchanger (12). The indoor heat exchanger (16) is configured to exchange heat between indoor air sent from the indoor fan and refrigerant flowing through the indoor heat exchanger (16).

The first and second expansion valves (15b, 15c) and the pressure reducing valve (15a) are both electronic expansion valves whose opening degrees can be adjusted. The first to fourth on-off valves (SV1, SV2, SV3, SV4) are composed of solenoid valves whose opening degree can be set to either full open or full close.

The supercooling heat exchanger (18) includes a high temperature side passage and a low temperature side passage, and is configured to exchange heat between the refrigerant passing through the high temperature side passage and the refrigerant passing through the low temperature side passage.

The heat storage heat exchanger (14) is housed in the ice heat storage tank (2), and includes a plurality of heat transfer tubes meandering up and down. The refrigerant flowing through the meandering heat transfer tube and the water or ice as the heat storage medium stored in the ice heat storage tank (2) are configured to exchange heat.

The end of the refrigerant pipe extending from the discharge side of the low-stage compressor (11a) is branched and connected to one end of the first and second branch pipes (20, 21). The other ends of the branch pipes (20, 21) merge and are connected to the suction side of the high-stage compressor (11b). The first branch pipe (20) is provided with the first on-off valve (SV1). The second branch pipe (21) includes a third on-off valve (SV3), the heat storage heat exchanger (14), and a second heat exchanger in order from the low stage compressor (11a) to the high stage compressor (11b). A 4 on-off valve (SV4) is provided.

The refrigerant pipe extending from the discharge side of the high stage compressor (11b) is connected to one end of the outdoor heat exchanger (12). The refrigerant pipe extending from the other end of the outdoor heat exchanger (12) branches, and one is connected to the inlet side of the low temperature side passage of the supercooling heat exchanger (18) via the pressure reducing valve (15a), The other is connected to the inlet side of the high temperature side passage of the supercooling heat exchanger (18).

The refrigerant pipe extending from the outlet side of the low temperature side passage of the supercooling heat exchanger (18) is formed between the high stage compressor (11b) and the first on-off valve (SV1) in the first branch pipe (20). Communicate with each other. On the other hand, the refrigerant pipe extending from the outlet side of the high temperature side passage of the supercooling heat exchanger (18) branches, and one of the refrigerant pipes is connected to one end of the indoor heat exchanger (16) via the first expansion valve (15b). The other is connected to between the heat storage heat exchanger (14) and the fourth on-off valve (SV4) in the second branch pipe (21) via the second expansion valve (15c).

The refrigerant pipe extending from the other end of the indoor heat exchanger (16) branches, one is connected to the suction side of the low-stage compressor (11a), and the other is connected via the second on-off valve (SV2). The second branch pipe (21) communicates with the third on-off valve (SV3) and the heat storage heat exchanger (14).

-Driving operation-
Next, the operation of the air conditioner (1) will be described. As described above, the air conditioner (1) is configured to be able to switch between a heat storage operation and a cold energy utilization operation.

<Heat storage operation>
In the heat storage operation, the low-stage compressor (11a) and the high-stage compressor (11b) are started by nighttime power, while the on-off valve (SV) is switched to store the heat storage heat exchanger (14). To the evaporator. And the cold of a refrigerant | coolant is stored by cooling the water of the said ice thermal storage tank (2) with the refrigerant | coolant which circulates through the said refrigerant | coolant circuit (10), and making it ice.

In the heat storage operation, as shown in FIG. 3, the opening degree of the first expansion valve (15b) is fully closed, and the opening degree of the second expansion valve (15c) and the pressure reducing valve (15a) is required. Adjusted accordingly. The first on-off valve (SV1) and the second on-off valve (SV2) are set to open, and the third on-off valve (SV3) and the fourth on-off valve (SV4) are set to close.

The supercritical high-pressure refrigerant discharged from the high-stage compressor (11b) flows into the outdoor heat exchanger (12), dissipates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12). To do. The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) is diverted, one of which is depressurized by the pressure reducing valve (15a) to become an intermediate pressure refrigerant, and then the low-temperature side stream of the supercooling heat exchanger (18) The other flows into the channel, and the other flows into the high-temperature channel of the supercooling heat exchanger (18).

In the supercooling heat exchanger (18), the high-pressure refrigerant in the high-temperature side channel and the intermediate-pressure refrigerant in the low-temperature side channel exchange heat. The high-pressure refrigerant dissipates heat to the intermediate-pressure refrigerant and is cooled, and flows out of the high-temperature side flow path. On the other hand, the intermediate-pressure refrigerant absorbs heat from the high-pressure refrigerant to become an intermediate-pressure gas refrigerant, and flows out from the low-temperature side flow path.

The intermediate-pressure refrigerant that has flowed out of the low-temperature channel of the supercooling heat exchanger (18) flows to the suction side of the high-stage compressor (11b).

The high-pressure refrigerant that has flowed out of the high-temperature channel of the supercooling heat exchanger (18) is reduced to a predetermined pressure by the second expansion valve (15c) to become a low-pressure refrigerant in a two-phase state, and then the heat storage It flows into the heat exchanger (14). In the heat storage heat exchanger (14), the low-pressure refrigerant and the water in the ice heat storage tank (2) exchange heat, and the water in the ice heat storage tank (2) is cooled to become ice. On the other hand, the low-pressure refrigerant that has absorbed heat from the water in the ice heat storage tank (2) becomes a low-pressure gas refrigerant and flows out of the heat storage heat exchanger (14).

The low-pressure gas refrigerant that has flowed out of the heat storage heat exchanger (14) passes through the second on-off valve (SV2), is sucked into the low-stage compressor (11a), and is compressed to a predetermined pressure to be intermediate-pressure gas refrigerant. After that, the low-stage compressor (11a) is discharged. The intermediate-pressure gas refrigerant discharged from the low-stage compressor (11a) passes through the first on-off valve (SV1) and flows out from the low-temperature side passage of the supercooling heat exchanger (18). After joining the refrigerant, the refrigerant is sucked into the high stage compressor (11b).

The intermediate-pressure gas refrigerant sucked into the high-stage compressor (11b) is compressed to a critical pressure or higher to become a high-pressure refrigerant, and then discharged from the high-stage compressor (11b). As the refrigerant circulates in this way, a heat storage operation is performed in the air conditioner (1).

<Cryogenic operation>
(First cold utilization operation)
In the first cold energy utilization operation, the low-stage compressor (11a) and the high-stage compressor (11b) are started by daytime power, and the on-off valve (SV) is switched to switch the heat storage heat exchanger. Set (14) as a radiator. And the refrigerant | coolant which flows through the said refrigerant circuit (10) is radiated using the cold energy stored in the said ice thermal storage tank (2) by the said thermal storage driving | operation.

In the cold energy utilization operation, as shown in FIG. 4A, the opening degrees of the second expansion valve (15c) and the pressure reducing valve (15a) are fully closed, and the first expansion valve (15b) is opened. The degree is adjusted as necessary. The third on-off valve (SV3) and the fourth on-off valve (SV4) are set to open, and the first on-off valve (SV1) and the second on-off valve (SV2) are set to close.

The supercritical high-pressure refrigerant discharged from the high-stage compressor (11b) flows into the outdoor heat exchanger (12), dissipates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12). (FIG. 4 (A), point c in FIG. 5). The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) passes through the supercooling heat exchanger (18) without exchanging heat, and flows into the first expansion valve (15b).

The high-pressure refrigerant that has flowed into the first expansion valve (15b) is depressurized to a predetermined pressure to become a two-phase low-pressure refrigerant, and flows out of the first expansion valve (15b) (FIGS. 4A and 5). Point d). The low-pressure refrigerant that has flowed out of the first expansion valve (15b) flows into the indoor heat exchanger (16), absorbs heat from the indoor air, becomes low-pressure gas refrigerant, and then enters the indoor heat exchanger (16). It flows out (point a in FIG. 4 (A) and FIG. 5). The indoor air is cooled by causing the low-pressure gas refrigerant to absorb the heat of the indoor air.

The low-pressure gas refrigerant flowing out of the indoor heat exchanger (16) is sucked into the low-stage compressor (11a) and compressed to a predetermined pressure to become an intermediate-pressure gas refrigerant. It is discharged from the machine (11a) (FIG. 4 (A), point a1 in FIG. 5). The intermediate-pressure gas refrigerant discharged from the low-stage compressor (11a) flows into the heat storage heat exchanger (14) through the third on-off valve (SV3).

In the heat storage heat exchanger (14), the intermediate pressure gas refrigerant and the ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts into water. On the other hand, the intermediate pressure gas refrigerant dissipates heat to the ice in the ice heat storage tank (2), is cooled, and flows out of the heat storage heat exchanger (14) (point a2 in FIGS. 4A and 5). .

The intermediate-pressure gas refrigerant that has flowed out of the heat storage heat exchanger (14) is sucked into the high-stage compressor (11b), compressed to a critical pressure or higher to become a high-pressure refrigerant, and then the high-stage compressor (11b) is discharged (point b in FIGS. 4A and 5). As the refrigerant circulates in this way, the cold air operation is performed in the air conditioner (1).

(Second cold energy operation)
In the second cold energy utilization operation, in FIG. 4B, the third on-off valve (SV3) is set to open, and the opening degree of at least one of the first expansion valve (15b) and the second expansion valve (15c) is required. Will be adjusted according to. Further, the first on-off valve (SV1), the second on-off valve (SV2), and the fourth on-off valve (SV4) are set to be closed, and the opening of the pressure reducing valve (15a) is fully closed. At this time, the low stage compressor (11a) is operated, and the high stage compressor (11b) is stopped.

In this state, the high-pressure refrigerant discharged from the low-stage compressor (11a) flows into the heat storage heat exchanger (14). In the heat storage heat exchanger (14), the high-pressure refrigerant and the ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts into water. On the other hand, the intermediate pressure gas refrigerant dissipates heat to the ice in the ice heat storage tank (2), is cooled, and flows out of the heat storage heat exchanger (14).

Next, when the refrigerant passes through the first expansion valve (15b) and the second expansion valve (15c), the refrigerant is depressurized to a predetermined pressure to become a two-phase low-pressure refrigerant, and flows out of the first expansion valve (15b). To do. The low-pressure refrigerant that has flowed out of the first expansion valve (15b) flows into the indoor heat exchanger (16), absorbs heat from the indoor air, becomes low-pressure gas refrigerant, and then enters the indoor heat exchanger (16). leak. The indoor air is cooled by causing the low-pressure gas refrigerant to absorb the heat of the indoor air.

The low-pressure gas refrigerant flowing out from the indoor heat exchanger (16) is sucked into the low-stage compressor (11a) and compressed to a predetermined pressure to become a high-pressure refrigerant, and then the low-stage compressor (11a) Discharged from 11a). As the refrigerant circulates in this way, the second cold energy utilization operation is performed in the air conditioner (1).

In the example of FIG. 4B, the low-stage compressor (11a) is started and the high-stage compressor (11b) is stopped. The circuit configuration of the refrigerant circuit (10) may be changed so that the compressor (11a) is stopped and the high-stage compressor (11b) is operated. When only one of the low-stage compressor (11a) and the high-stage compressor (11b) is activated during the cold energy operation, the refrigerant transport power during the cold energy operation is reduced compared to during the heat storage operation. can do. Therefore, the power consumption of the compression mechanism can be reduced.

-Effect of Embodiment 1-
According to the first embodiment, the ice storage tank (2) is provided in the air conditioner (1), and the first to fourth on-off valves (SV1 to SV4) are provided in the refrigerant circuit (10). Thus, the air conditioner (1) can perform the cold energy use operation and the heat storage operation.

Also, the low-stage compressor (11a) and the high-stage compressor (11b), which are the compression mechanisms of the refrigerant circuit (30), are allowed to perform two-stage compression in the cold utilization operation, and the low-stage side The refrigerant discharged from the compressor (11a) is cooled by the heat storage heat exchanger (14) and then sucked into the high-stage compressor (11b).

In this way, when the compression mechanism of the refrigerant circuit (10) is configured by single-stage compression and when it is configured as in the first embodiment, if the power consumption is the same, the compression of the single-stage compression is performed. The refrigerating capacity of the refrigerating apparatus having the compression mechanism (11) of the first embodiment is greater than that of the refrigerating apparatus having the mechanism (11). That is, the refrigerating capacity can be increased without increasing the power consumption.

Further, in the air conditioner (1), the first to fourth on-off valves (SV1 to SV4) are switched as shown in FIG. 3 to perform the heat storage operation and use relatively inexpensive nighttime power. Cold water is stored by cooling the water in the ice heat storage tank (2) to produce ice. Then, the first to fourth on-off valves (SV1 to SV4) are switched as shown in FIG. 4 to perform cold heat operation during the daytime, and the ice generated during the heat storage operation is used to reduce daytime power consumption. be able to.

That is, the peak power shift of the daytime power can be performed, and the refrigeration capacity of the conventional refrigeration apparatus can be approached without increasing the power consumption of the compression mechanism (11).

Moreover, according to the first embodiment, carbon dioxide is used as the refrigerant flowing through the refrigerant circuit (10). When this carbon dioxide is compared with the current HFC-based refrigerant, the latent heat increases and the refrigerant density increases as the saturation pressure decreases. Therefore, the capacity | capacitance at the time of the heat storage driving | operation of the said air conditioning apparatus (1) can be improved by using the said carbon dioxide.

—Modification 1 of Embodiment 1—
6 is a refrigerant circuit diagram of an air conditioner (1) according to Modification 1 of Embodiment 1. FIG. 7 shows the refrigerant flow during the heat storage operation, and FIG. 8 shows the refrigerant flow during the cold energy use operation. Show. FIG. 9 is a diagram showing a refrigeration cycle during a cold energy operation on a Ph graph of carbon dioxide.

In the refrigerant circuit (10) of the first embodiment, the heat storage heat exchanger (14) is connected between the low-stage compressor (11a) and the high-stage compressor (11b). In the refrigerant circuit (30) of Example 1, a second heat storage heat exchanger (19) different from the heat storage heat exchanger (14) is connected between the supercooling heat exchanger (18) and the expansion valve. Has been. The refrigerant circuit (30) is provided with a flow rate adjustment valve (13) instead of the second expansion valve (15c) of the first embodiment. The refrigerant circuit (30) is provided with fifth and sixth on-off valves (SV5, SV6).

Here, the heat storage heat exchanger (14) connected between the low stage compressor (11a) and the high stage compressor (11b) is referred to as a first heat storage heat exchanger (14). Both the first and second heat storage heat exchangers (14, 19) are accommodated in the ice heat storage tank (2).

Specifically, the end of the refrigerant pipe extending from the discharge side of the low-stage compressor (11a) is branched and connected to one end of the first and second branch pipes (20, 21). The other ends of the branch pipes (20, 21) merge and are connected to the suction side of the high-stage compressor (11b). The first branch pipe (20) is provided with the first on-off valve (SV1). The second branch pipe (21) includes a third on-off valve (SV3), the heat storage heat exchanger (14), and a second heat exchanger in order from the low stage compressor (11a) to the high stage compressor (11b). A 4 on-off valve (SV4) is provided.

The refrigerant pipe extending from the outlet side of the low temperature side passage of the supercooling heat exchanger (18) is between the high stage compressor (11b) and the first on-off valve (SV1) in the first branch pipe (20). Communicated with. On the other hand, the refrigerant pipe extending from the outlet side of the high temperature side passage of the supercooling heat exchanger (18) branches via the flow rate adjusting valve (13), and one of the refrigerant pipes is connected to one end of the second heat storage heat exchanger (19). The other is connected via the fifth on-off valve (SV5) to the first heat storage heat exchanger (14) and the fourth on-off valve (SV4) in the second branch pipe (21).

The refrigerant pipe extending from the other end of the second heat storage heat exchanger (19) is connected to one end of the indoor heat exchanger (16) through an expansion valve (15). The refrigerant pipe extending from the other end of the indoor heat exchanger (16) branches, one is connected to the suction side of the low-stage compressor (11a), and the other is connected via the second on-off valve (SV2). The second branch pipe (21) communicates with the third on-off valve (SV3) and the first heat storage heat exchanger (14).

The refrigerant circuit (30) is provided with a bypass pipe that bypasses the expansion valve (15) and the indoor heat exchanger (16), and the bypass pipe is provided with a sixth on-off valve (SV6). It has been.

-Driving operation-
<Heat storage operation>
In the heat storage operation, as shown in FIG. 7, the opening degree of the expansion valve (15) is fully closed, and the opening degree of the flow rate adjusting valve (13) and the pressure reducing valve (15a) is adjusted as necessary. Is done. In addition, the first on-off valve (SV1), the second on-off valve (SV2), the fifth on-off valve (SV5), and the sixth on-off valve (SV6) are set open, and the third on-off valve (SV3) and The fourth on-off valve (SV4) is set to be closed.

The supercritical high-pressure refrigerant discharged from the high-stage compressor (11b) flows into the outdoor heat exchanger (12), dissipates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12). To do. The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) is diverted, one of which is depressurized by the pressure reducing valve (15a) to become an intermediate pressure refrigerant, and then the low-temperature side stream of the supercooling heat exchanger (18) The other flows into the channel, and the other flows into the high temperature side channel of the supercooling heat exchanger (18).

The high-pressure refrigerant that has flowed out of the high-temperature side flow path of the supercooling heat exchanger (18) flows into the flow rate adjusting valve (13), the flow rate is adjusted and the pressure is reduced, and then the low-pressure refrigerant in a two-phase state And flows out of the flow regulating valve (13). The low-pressure refrigerant that has flowed out of the flow rate adjusting valve (13) is divided, one flows into the second heat storage heat exchanger (19), and the other passes through the fifth on-off valve (SV5) and the first heat storage heat exchanger ( 14).

In the first and second heat storage heat exchangers (14, 19), the low-pressure refrigerant and the water in each ice heat storage tank (2) exchange heat, and the water in each ice heat storage tank (2). Is cooled to ice. On the other hand, the low-pressure refrigerant that has absorbed heat from the water in each of the ice heat storage tanks (2) becomes a low-pressure gas refrigerant and flows out of the heat storage heat exchangers (14).

The low-pressure gas refrigerants that have flowed out of the first and second heat storage heat exchangers (14, 19) join together, and are then sucked into the low-stage compressor (11a) and compressed to a predetermined pressure, so that an intermediate-pressure gas is obtained. After becoming a refrigerant, the refrigerant is discharged from the low stage compressor (11a). The intermediate-pressure gas refrigerant discharged from the low-stage compressor (11a) passes through the first on-off valve (SV1) and flows out from the low-temperature side passage of the supercooling heat exchanger (18). After joining the refrigerant, the refrigerant is sucked into the high stage compressor (11b).

<Cryogenic operation>
In the cold energy utilization operation, as shown in FIG. 8, the opening of the pressure reducing valve (15a) is fully closed, and the openings of the flow rate adjusting valve (13) and the expansion valve (15) are adjusted as necessary. Adjusted. The first on-off valve (SV1), the second on-off valve (SV2), the fifth on-off valve (SV5), and the sixth on-off valve (SV6) are set to be closed, and the third on-off valve (SV3) and The fourth on-off valve (SV4) is set to open.

The supercritical high-pressure refrigerant discharged from the high-stage compressor (11b) flows into the outdoor heat exchanger (12), dissipates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12). (Point b1 in FIGS. 8 and 9). The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) passes through the supercooling heat exchanger (18) without exchanging heat, and the flow rate of the high-pressure refrigerant is adjusted by the flow rate adjusting valve (13). 2 flows into the heat storage heat exchanger (19).

In the second heat storage heat exchanger (19), the high-pressure refrigerant and the ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts into water. On the other hand, the high-pressure refrigerant radiates and cools the ice in the ice heat storage tank (2) and then flows out of the second heat storage heat exchanger (19) (point c in FIGS. 8 and 9).

The high-pressure refrigerant that has flowed out of the second heat storage heat exchanger (19) flows into the expansion valve (15), is reduced to a predetermined pressure, becomes a low-pressure refrigerant in a two-phase state, and flows out of the expansion valve (15). (Point d in FIGS. 8 and 9). The low-pressure refrigerant that has flowed out of the expansion valve (15) flows into the indoor heat exchanger (16), absorbs heat from the indoor air, becomes low-pressure gas refrigerant, and then flows out of the indoor heat exchanger (16). (Point a in FIGS. 8 and 9). The indoor air is cooled by causing the low-pressure gas refrigerant to absorb the heat of the indoor air.

The low-pressure gas refrigerant flowing out of the indoor heat exchanger (16) is sucked into the low-stage compressor (11a) and compressed to a predetermined pressure to become an intermediate-pressure gas refrigerant. It is discharged from the machine (11a) (point a1 in FIGS. 8 and 9). The intermediate-pressure gas refrigerant discharged from the low-stage compressor (11a) flows into the first heat storage heat exchanger (14) through the third on-off valve (SV3).

In the first heat storage heat exchanger (14), the intermediate pressure gas refrigerant and the ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts into water. Become. On the other hand, the intermediate-pressure gas refrigerant dissipates heat to the ice in the ice heat storage tank (2), is cooled, and flows out of the first heat storage heat exchanger (14) (point a2 in FIGS. 8 and 9).

The intermediate-pressure gas refrigerant that has flowed out of the first heat storage heat exchanger (14) passes through the fourth on-off valve (SV4) and is sucked into the high-stage compressor (11b) and compressed to a critical pressure or higher. After becoming a refrigerant, the refrigerant is discharged from the high stage compressor (11b) (point b in FIGS. 8 and 9). As the refrigerant circulates in this way, the cold air operation is performed in the air conditioner (1).

-Effect of Modification 1 of Embodiment 1-
According to the first modification of the first embodiment, the low-stage compressor (11a) and the high-stage compressor (11b), which are compression mechanisms of the refrigerant circuit (30), are subjected to two-stage compression, The refrigerant discharged from the low stage compressor (11a) is cooled by the first heat storage heat exchanger (14). If it carries out like this, refrigerating capacity can be increased, without increasing power consumption similarly to Embodiment 1. FIG.

Also, by providing the second heat storage heat exchanger (19), the temperature of the refrigerant flowing out from the heat source side heat exchanger (12) can be further lowered, and the refrigeration effect can be improved. Thereby, the circulation amount of the refrigerant in the refrigerant circuit (30) can be reduced by the amount that the refrigeration effect is improved, and the power consumption of the compression mechanism of the refrigerant circuit (30) can be reduced.

As described above, by providing the first and second heat storage heat exchangers (14, 19) which are heat dissipating means different from the heat source side heat exchanger (12), the power consumption of the refrigerant circuit (30). It is possible to approach the refrigeration capacity of the conventional refrigeration apparatus without increasing the value.

—Modification 2 of Embodiment 1
FIG. 10 is a refrigerant circuit diagram of the air conditioner (1) according to the second modification of the first embodiment. FIG. 11 shows the refrigerant flow during the heat storage operation, and FIG. 12 shows the refrigerant flow during the cold utilization operation. Show. FIG. 13 is a diagram showing a refrigeration cycle at the time of operation using cold energy on a Ph diagram of carbon dioxide.

In the refrigerant circuit (10) of the first embodiment, the heat storage heat exchanger (14) is connected between the low-stage compressor (11a) and the high-stage compressor (11b). In the refrigerant circuit (40) of Example 2, the heat storage heat exchanger (14) is connected to another position.

The connection pipe (22) extending from the discharge side of the low stage compressor (11a) is connected to the suction side of the high stage compressor (11b). A refrigerant pipe extending from the discharge side of the high stage compressor (11b) is connected to one end of the outdoor heat exchanger (12). The refrigerant pipe extending from the other end of the outdoor heat exchanger (12) branches, and one is connected to the inlet side of the low temperature side passage of the supercooling heat exchanger (18) via the pressure reducing valve (15a), The other is connected to the inlet side of the high temperature side passage of the supercooling heat exchanger (18).

The refrigerant pipe extending from the outlet side of the low temperature side passage of the supercooling heat exchanger (18) communicates with the connection pipe (22). On the other hand, the refrigerant pipe extending from the outlet side of the high-temperature side passage of the supercooling heat exchanger (18) branches via the flow rate adjusting valve (13), and one is connected to one end of the heat storage heat exchanger (14). The other is connected to one end of the indoor heat exchanger (16) through the expansion valve (15).

The refrigerant pipe extending from the other end of the heat storage heat exchanger (14) communicates with the connection pipe (22) through a seventh on-off valve (SV7). On the other hand, the refrigerant pipe extending from the other end of the indoor heat exchanger (16) branches, and one end of the refrigerant pipe extends from the other end of the heat storage heat exchanger (14) via an eighth on-off valve (SV8). The heat storage heat exchanger (14) communicates with the seventh on-off valve (SV7), and the other end is connected to the suction side of the low-stage compressor (11a).

-Driving operation-
<Heat storage operation>
In the heat storage operation, as shown in FIG. 11, the opening degree of the expansion valve (15) is fully closed, and the opening degree of the flow rate adjusting valve (13) and the pressure reducing valve (15a) is adjusted as necessary. Is done. The eighth on-off valve (SV8) is set to open, and the seventh on-off valve (SV7) is set to close.

The high-pressure refrigerant that has flowed out of the high-temperature side flow path of the supercooling heat exchanger (18) flows into the flow rate adjusting valve (13), the flow rate is adjusted and the pressure is reduced, and then the low-pressure refrigerant in a two-phase state And flows out of the flow regulating valve (13). The low-pressure refrigerant that has flowed out of the flow control valve (13) flows into the heat storage heat exchanger (14).

In the heat storage heat exchanger (14), the low-pressure refrigerant and water in the ice heat storage tank (2) exchange heat, and the water in the ice heat storage tank (2) is cooled to become ice. On the other hand, the low-pressure refrigerant that has absorbed heat from the water in the ice heat storage tank (2) becomes a low-pressure gas refrigerant and flows out of the heat storage heat exchanger (14).

The low-pressure gas refrigerant that has flowed out of the heat storage heat exchanger (14) passes through the eighth on-off valve (SV8), is sucked into the low-stage compressor (11a), is compressed to a predetermined pressure, and is compressed to an intermediate pressure gas. After becoming a refrigerant, the refrigerant is discharged from the low stage compressor (11a).

The intermediate-pressure gas refrigerant discharged from the low-stage compressor (11a) merges with the intermediate-pressure gas refrigerant flowing out from the low-temperature side flow path of the supercooling heat exchanger (18), and then the high-stage compression Inhaled into the machine (11b).

<Cryogenic operation>
In the cold energy utilization operation, as shown in FIG. 12, the opening degree of the expansion valve (15) is adjusted as necessary, and the opening degree of the flow rate adjusting valve (13) and the pressure reducing valve (15a) are fully closed. It becomes. Further, the eighth on-off valve (SV8) is set to close, and the seventh on-off valve (SV7) is set to open. The high stage compressor (11b) is stopped.

The high-pressure gas refrigerant discharged from the low-stage compressor (11a) flows into the heat storage heat exchanger (14) through the seventh on-off valve (SV7).

In the heat storage heat exchanger (14), the high pressure gas refrigerant and the ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts to become water. On the other hand, the high-pressure gas refrigerant releases heat to the ice in the ice heat storage tank (2) and condenses, and then flows out of the heat storage heat exchanger (14) (point c in FIGS. 12 and 13).

The high-pressure refrigerant that has flowed out of the heat storage heat exchanger (14) flows into the expansion valve (15), is depressurized to a predetermined pressure, becomes a low-pressure refrigerant in a two-phase state, and flows out of the expansion valve (15) ( Point d) in FIGS. The low-pressure refrigerant that has flowed out of the expansion valve (15) flows into the indoor heat exchanger (16), absorbs heat from the indoor air, becomes low-pressure gas refrigerant, and then flows out of the indoor heat exchanger (16). (Point a in FIGS. 12 and 13). The indoor air is cooled by causing the low-pressure gas refrigerant to absorb the heat of the indoor air.

The low-pressure gas refrigerant that has flowed out of the indoor heat exchanger (16) is sucked into the low-stage compressor (11a) and compressed within the range below the critical pressure to become a high-pressure gas refrigerant. It is discharged from the side compressor (11a) (point b in FIGS. 12 and 13). As the refrigerant circulates in this way, the cold air operation is performed in the air conditioner (1).

-Effects of Modification 2 of Embodiment 1-
According to the second modification of the first embodiment, the low-stage compressor (11a) and the high-stage compressor (11b) are started during the heat storage operation. Only the low stage compressor (11a) is running. Thereby, compared with the time of the said heat storage driving | operation, the refrigerant | coolant conveyance motive power at the time of the said cold utilization operation | movement can be reduced. Therefore, it is possible to increase the refrigeration capacity during the cold heat operation without increasing the power consumption of the compression mechanism of the refrigerant circuit (40).

<< Embodiment 2 >>
FIG. 14 is a refrigerant circuit diagram of the air-conditioning apparatus (1) according to Embodiment 2. FIG. 15 shows the refrigerant flow during the heat storage operation, and FIG. 16 shows the refrigerant flow during the cold utilization operation. FIG. 17 is a diagram showing a refrigeration cycle during a cold heat operation on a Ph graph of carbon dioxide.

The major difference between the refrigerant circuit (50) of the second embodiment and the refrigerant circuit (10) shown in the first embodiment is that the compression is performed in place of the low-stage compressor (11a) and the high-stage compressor (11b). The machine (11) and the refrigerant gas pump (refrigerant pump) (17) are provided, and the position of the heat storage heat exchanger (14) is different. Here, the refrigerant gas pump (17) is for conveying refrigerant gas, and has a compression ratio smaller than that of the compressor (11).

The refrigerant pipes extending from the discharge side of the compressor (11) and the refrigerant gas pump (17) merge and are connected to one end of the outdoor heat exchanger (12). A refrigerant pipe extending from the other end of the outdoor heat exchanger (12) is connected to one end of the indoor heat exchanger (16) through the flow rate adjusting valve (13) and the expansion valve (15). The refrigerant pipe extending from the other end of the indoor heat exchanger (16) branches, one end is connected to the suction side of the compressor (11), and the other end is connected to the suction side of the refrigerant gas pump (17). ing.

The refrigerant circuit (50) is provided with a bypass pipe (23) that bypasses the outdoor heat exchanger (12) and the flow rate adjusting valve (13), and is provided from the outdoor heat exchanger (12) side. A ninth on-off valve (SV9) and the heat storage heat exchanger (14) are provided toward the flow rate adjustment valve (13). A branch pipe (24) extending from between the ninth on-off valve (SV9) and the heat storage heat exchanger (14) in the bypass pipe (23) is connected to the indoor heat exchanger (16) and the compressor (11). And a refrigerant pipe connecting the refrigerant gas pump (17). A tenth on-off valve (SV10) is connected to the branch pipe (24).

Thus, the refrigerant circuit (10) includes the refrigerant gas pump (17) for conveying the refrigerant. In the refrigerant circuit (10), the refrigerant discharged from the compression mechanism (11) dissipates heat in the heat source side heat exchanger (12), evaporates in the heat storage heat exchanger (14), and enters the compression mechanism (11) The return heat storage operation, and the refrigerant discharged from the refrigerant gas pump (17) is condensed in the heat storage heat exchanger (14), evaporated in the use side heat exchanger (16), and returned to the refrigerant pump (17). It is comprised so that it may switch.

-Driving operation-
<Heat storage operation>
In the heat storage operation, as shown in FIG. 15, the opening degree of the expansion valve (15) is fully closed, and the opening degree of the flow rate adjusting valve (13) is adjusted as necessary. The tenth on-off valve (SV10) is set to open, and the ninth on-off valve (SV9) is set to close.

The supercritical high-pressure refrigerant discharged from the compressor (11) flows into the outdoor heat exchanger (12), dissipates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12). The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) flows into the flow rate adjustment valve (13), the flow rate is adjusted and the pressure is reduced, and then the low-pressure refrigerant is in a two-phase state. Outflow valve (13). The low-pressure refrigerant that has flowed out of the flow control valve (13) flows into the heat storage heat exchanger (14).

The low-pressure gas refrigerant that has flowed out of the heat storage heat exchanger (14) passes through the tenth on-off valve (SV10), is sucked into the compressor (11), and is compressed to a predetermined pressure to be supercritical high-pressure refrigerant. After that, it is discharged from the compressor (11). As the refrigerant circulates in this way, a heat storage operation is performed in the air conditioner (1).

<Cryogenic operation>
In the cold energy utilization operation, as shown in FIG. 16, the opening degree of the flow rate adjustment valve (13) is fully closed, and the opening degree of the expansion valve (15) is adjusted as necessary. Further, the tenth on-off valve (SV10) is set to be closed, and the ninth on-off valve (SV9) is set to be open.

The refrigerant discharged from the refrigerant gas pump (17) flows into the heat storage heat exchanger (14) through the ninth on-off valve (SV9).

In the heat storage heat exchanger (14), the refrigerant and ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts to become water. On the other hand, the refrigerant releases heat to the ice in the ice heat storage tank (2) and condenses, and then flows out of the heat storage heat exchanger (14) (point c in FIGS. 16 and 17).

The refrigerant that has flowed out of the heat storage heat exchanger (14) flows into the expansion valve (15), is depressurized to a predetermined pressure, and then flows out of the expansion valve (15) (points in FIGS. 16 and 17). d). The refrigerant that has flowed out of the expansion valve (15) flows into the indoor heat exchanger (16), absorbs heat from indoor air, and then flows out of the indoor heat exchanger (16) (points in FIGS. 16 and 17). a). The indoor air is cooled by causing the refrigerant to absorb the heat of the indoor air.

The refrigerant flowing out of the indoor heat exchanger (16) is sucked into the refrigerant gas pump (17) and then discharged from the refrigerant gas pump (17) (point b in FIGS. 16 and 17). As the refrigerant circulates in this way, the cold air operation is performed in the air conditioner (1).

-Effect of Embodiment 2-
According to the second embodiment, the refrigerant pump (17) is used without using the compression mechanism (11) during the cold heat operation. By carrying out like this, the refrigerant | coolant conveyance motive power at the time of the said cold utilization operation can be reduced. Thereby, compared with the time of the said heat storage driving | operation, the refrigerant | coolant conveyance motive power at the time of the said cold utilization operation | movement can be reduced. Therefore, as in the second modification of the first embodiment, the refrigeration capacity during the cold-utilizing operation can be increased without increasing the power consumption of the compression mechanism of the refrigerant circuit (50).

<< Embodiment 3 >>
18 is a refrigerant circuit diagram of the air-conditioning apparatus (1) according to Embodiment 3. FIG. 19 shows the refrigerant flow during the heat storage operation, and FIG. 20 shows the refrigerant flow during the cold energy use operation. FIG. 21 is a diagram showing a refrigeration cycle at the time of operation using cold energy on a Ph diagram of carbon dioxide.

The major difference between the refrigerant circuit (60) of the second embodiment and the refrigerant circuit (10) shown in the first embodiment is that the low-stage compressor (11a) and the high-stage compressor (11b) are replaced with 1 Only the compressor (11) is provided, and the position of the heat storage heat exchanger (14) is different.

The refrigerant pipe extending from the discharge side of the compressor (11) is connected to one end of the heat storage heat exchanger (14) via the outdoor heat exchanger (12) and the flow rate adjusting valve (13). A refrigerant pipe extending from the other end of the heat storage heat exchanger (14) is connected to the suction side of the compressor (11) via the expansion valve (15) and the indoor heat exchanger (16). The refrigerant pipe is provided with a bypass pipe that bypasses the expansion valve (15) and the indoor heat exchanger (16), and the bypass pipe is provided with an eleventh on-off valve (SV11).

-Driving operation-
<Heat storage operation>
In the heat storage operation, as shown in FIG. 19, the opening degree of the expansion valve (15) is fully closed, and the opening degree of the flow rate adjusting valve (13) is adjusted as necessary. The eleventh on-off valve (SV11) is set to open.

The low-pressure gas refrigerant that has flowed out of the heat storage heat exchanger (14) passes through the eleventh on-off valve (SV11), is sucked into the compressor (11), and is compressed to a predetermined pressure so that it is in a supercritical state. After that, it is discharged from the compressor (11). As the refrigerant circulates in this way, a heat storage operation is performed in the air conditioner (1).

<Cryogenic operation>
In the cold energy utilization operation, as shown in FIG. 20, the opening degrees of the expansion valve (15) and the flow rate adjustment valve (13) are adjusted as necessary. The eleventh on-off valve (SV11) is set to be closed.

The supercritical high-pressure refrigerant discharged from the compressor (11) flows into the outdoor heat exchanger (12), dissipates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12) (FIG. 20, point b1) in FIG. The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) flows into the heat storage heat exchanger (14) after the flow rate is adjusted by the flow rate adjustment valve (13).

In the heat storage heat exchanger (14), the high-pressure refrigerant and the ice in the ice heat storage tank (2) exchange heat, and the ice in the ice heat storage tank (2) melts to become water. On the other hand, the high-pressure refrigerant releases heat to the ice in the ice heat storage tank (2) and is cooled, and then flows out of the heat storage heat exchanger (14) (point c in FIGS. 20 and 21).

The high-pressure refrigerant that has flowed out of the heat storage heat exchanger (14) flows into the expansion valve (15), is depressurized to a predetermined pressure, becomes a low-pressure refrigerant in a two-phase state, and flows out of the expansion valve (15) ( The point d) of FIG. 20, FIG. The low-pressure refrigerant that has flowed out of the expansion valve (15) flows into the indoor heat exchanger (16), absorbs heat from the indoor air, becomes low-pressure gas refrigerant, and then flows out of the indoor heat exchanger (16). (Point a in FIGS. 20 and 21). The indoor air is cooled by causing the low-pressure gas refrigerant to absorb the heat of the indoor air.

The low-pressure gas refrigerant flowing out of the indoor heat exchanger (16) is sucked into the compressor (11) and compressed to a predetermined pressure to become a high-pressure refrigerant in a supercritical state, and then the compressor (11) (Point b in FIGS. 20 and 21). As the refrigerant circulates in this way, the cold air operation is performed in the air conditioner (1).

-Effect of Embodiment 3-
According to the third embodiment, the heat storage heat exchanger (14) is connected between the heat source side heat exchanger (12) and the expansion valve (15) of the refrigerant circuit (60). If it carries out like this, the temperature of the refrigerant | coolant which flowed out from the said heat-source side heat exchanger (12) can further be lowered | hung by the said heat storage heat exchanger (14), and the said freezing effect can be improved. Thereby, the circulation amount of the refrigerant in the refrigerant circuit (10) can be reduced by the amount that the refrigeration effect is improved, and the power consumption of the compressor (11) can be reduced.

From the above, by providing the heat storage heat exchanger (14), the refrigeration capacity of the air conditioner (1) can be increased without increasing the power consumption.

-Modification of Embodiment 3-
22 is a refrigerant circuit diagram of an air conditioner (1) according to a modification of the third embodiment. FIG. 23 shows the refrigerant flow during the heat storage operation, and FIG. 24 shows the refrigerant flow during the cold energy use operation. ing. FIG. 25 is a diagram showing a refrigeration cycle at the time of operation using cold energy on a Ph diagram of carbon dioxide.

In the air conditioner (1) of the first embodiment, the heat storage heat exchanger (14) is connected between the outdoor heat exchanger (12) and the expansion valve. In the refrigerant circuit (70), the heat storage heat exchanger (14) is connected in parallel with the heat source side heat exchanger (12).

The refrigerant pipe extending from the discharge side of the compressor (11) is connected to one end of the outdoor heat exchanger (12). The other end of the outdoor heat exchanger (12) is connected to one end of the indoor heat exchanger (16) through the flow rate adjusting valve (13) and the expansion valve (15). The other end of the indoor heat exchanger (16) is connected to the suction side of the compressor (11).

The refrigerant circuit (70) is provided with a bypass pipe (23) that bypasses the outdoor heat exchanger (12) and the flow rate adjusting valve (13), and is provided from the outdoor heat exchanger (12) side. A twelfth on-off valve (SV12) and the heat storage heat exchanger (14) are provided toward the flow rate adjustment valve (13). A branch pipe (24) extending from between the twelfth on-off valve (SV12) and the heat storage heat exchanger (14) in the bypass pipe (23) is connected to the indoor heat exchanger (16) and the compressor (11). Is connected to the refrigerant pipe connecting the two. A thirteenth on-off valve (SV13) is connected to the branch pipe (24).

-Driving operation-
<Heat storage operation>
In the heat storage operation, as shown in FIG. 23, the opening degree of the expansion valve (15) is fully closed, and the opening degree of the flow rate adjusting valve (13) is adjusted as necessary. The twelfth on-off valve (SV12) is set to be closed, and the thirteenth on-off valve (SV13) is set to be open.

The low-pressure gas refrigerant flowing out of the heat storage heat exchanger (14) is sucked into the compressor (11) through the thirteenth on-off valve (SV13) and compressed to a predetermined pressure to be supercritical high-pressure refrigerant. After that, it is discharged from the compressor (11). As the refrigerant circulates in this way, a heat storage operation is performed in the air conditioner (1).

<Cryogenic operation>
In the cold utilization operation, as shown in FIG. 24, the opening degrees of the expansion valve (15) and the flow rate adjustment valve (13) are adjusted as necessary. The twelfth on-off valve (SV12) is set to open, and the thirteenth on-off valve (SV13) is set to closed.

The supercritical high-pressure refrigerant discharged from the compressor (11) is diverted, one flows into the outdoor heat exchanger (12), and the other passes through the twelfth on-off valve (SV12) and the heat storage. It flows into the heat exchanger (14) (point b1 in FIGS. 24 and 25).

The high-pressure refrigerant that has flowed into the outdoor heat exchanger (12) radiates heat to the outdoor air, and then flows out of the outdoor heat exchanger (12) (point c in FIGS. 24 and 25). On the other hand, the refrigerant flowing into the heat storage heat exchanger (14) exchanges heat with the ice in the ice heat storage tank (2), and the ice in the ice heat storage tank (2) melts to become water. On the other hand, after the refrigerant dissipates heat to the ice in the ice heat storage tank (2) and is cooled, it flows out of the heat storage heat exchanger (14) (point c2 in FIGS. 24 and 25).

The high-pressure refrigerant that has flowed out of the outdoor heat exchanger (12) flows into the flow rate adjustment valve (13), and after the flow rate is adjusted and reduced, the flow rate adjustment valve (13) flows out. The refrigerants flowing out of the flow rate adjusting valve (13) and the heat storage heat exchanger (14) merge (point c1 in FIGS. 24 and 25), flow into the expansion valve (15), and reach a predetermined pressure. The pressure is reduced to become a low-pressure refrigerant in a two-phase state, and flows out from the expansion valve (15) (point d in FIGS. 24 and 25). The low-pressure refrigerant that has flowed out of the expansion valve (15) flows into the indoor heat exchanger (16), absorbs heat from the indoor air, becomes low-pressure gas refrigerant, and then flows out of the indoor heat exchanger (16). (Point a in FIGS. 24 and 25). The indoor air is cooled by causing the low-pressure gas refrigerant to absorb the heat of the indoor air.

The low-pressure gas refrigerant flowing out of the indoor heat exchanger (16) is sucked into the compressor (11) and compressed to a predetermined pressure to become a high-pressure refrigerant in a supercritical state, and then the compressor (11) (Point b in FIGS. 24 and 25). As the refrigerant circulates in this way, the cold air operation is performed in the air conditioner (1).

-Effect of Modification of Embodiment 3-
According to the modification of Embodiment 3, the heat storage heat exchanger (14) is connected in parallel with the heat source side heat exchanger (12) of the refrigerant circuit (70). If it carries out like this, the refrigerant | coolant discharged from the said compressor (11) can be shunted, one side can be radiated with the said heat source side heat exchanger (12), and the other with the thermal storage heat exchanger (14). As in the third embodiment, if the heat storage heat exchanger (14) is connected in series to the heat source side heat exchanger (12), the heat storage use amount (peak shift amount) is small, and heat storage use The amount of power increases.

As in the modification of the third embodiment, when the heat storage heat exchanger (14) is connected in parallel with the heat source side heat exchanger (12) and the refrigerant discharged from the compression mechanism (11) is divided, Since the amount of heat storage use can be increased, the amount of power during use operation is reduced.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

In the present embodiment, the operation state of the air conditioner (1) is switched to the heat storage operation or the cold energy use operation using a plurality of on-off valves (SV). However, the present invention is not limited to this. The operating state of the air conditioner (1) may be switched by a valve or a four-way valve.

In the present embodiment, in the air conditioner (1), carbon dioxide is used as a refrigerant, but the present invention is not limited to this, and other natural refrigerants may be used. In this case, it is necessary to configure the refrigerant circuit in which the natural refrigerant is sealed to perform the supercritical refrigeration cycle.

In addition, the above embodiment is an essentially preferable example, and is not intended to limit the scope of the present invention, its application, or its use.

As described above, the present invention is useful for a refrigeration apparatus including a refrigerant circuit that performs a supercritical refrigeration cycle.

1 Air conditioner (refrigeration equipment)
2 Ice heat storage tank 3 Outdoor unit 4 Indoor unit 10 Refrigerant circuit 11 Compressor (compression mechanism)
12 Outdoor heat exchanger (heat source side heat exchanger)
14 Heat storage heat exchanger 15 Expansion valve (expansion mechanism)
16 Indoor heat exchanger (use side heat exchanger)

Claims

A refrigeration apparatus comprising a refrigerant circuit (10) that performs a supercritical refrigeration cycle by connecting a compression mechanism (11), a heat source side heat exchanger (12), an expansion mechanism (15), and a use side heat exchanger (16) Because
A heat storage heat exchanger (14) for storing water or ice as a heat storage medium and exchanging heat between the heat storage medium and the refrigerant in the refrigerant circuit (10) connected to the refrigerant circuit (10); The heat exchanger (14) is equipped with an ice heat storage tank (2) that becomes a radiator when using the cold energy of the heat storage medium,
The compression mechanism (11) includes a low-stage compressor (11a) and a high-stage compressor (11b),
The refrigeration apparatus, wherein the heat storage heat exchanger (14) is connected between the low-stage compressor (11a) and the high-stage compressor (11b).
In claim 1,
The heat storage heat exchanger (14) is a first heat storage heat exchanger (14) connected between the low stage compressor (11a) and the high stage compressor (11b),
The refrigerating apparatus further comprises a second heat storage heat exchanger (19) connected between the heat source side heat exchanger (12) and the expansion mechanism (15) of the refrigerant circuit (10). .
In claim 1,
In the refrigerant circuit (10), the heat storage heat exchanger (14) is used as a radiator and the cold storage operation using the cold heat of the ice storage tank (2) and the heat storage heat exchanger (14) is used as an ice A refrigeration apparatus comprising a switching mechanism (SV) capable of switching to a heat storage operation for storing cold energy in a heat storage tank (2).
In claim 3,
The refrigerant circuit (10) is configured to start the low-stage compressor (11a) or the high-stage compressor (11b) at the time of the cold utilization operation.
In claim 1,
The refrigeration apparatus characterized in that the refrigerant flowing through the refrigerant circuit (10) is carbon dioxide.