WO2016103690A1

WO2016103690A1 - Regenerative air conditioner

Info

Publication number: WO2016103690A1
Application number: PCT/JP2015/006407
Authority: WO
Inventors: 修二藤本; 安尾　晃一; 柯壁陳; 拓哉中尾
Original assignee: ダイキン工業株式会社
Priority date: 2014-12-26
Filing date: 2015-12-22
Publication date: 2016-06-30
Also published as: EP3249320A4; EP3249320B1; ES2833435T3; JP6020550B2; EP3249320A1; JP2016125736A

Abstract

In a refrigerant circuit (11): a discharge end of a compressor (21) is connected to a gas end of an outdoor heat exchanger (22); a suction end of the compressor (21) is connected to a gas refrigerant flow path (13); and a refrigeration-and-cold-storage cycle is performed in which an outdoor heat exchanger (22) serves as a condenser and an indoor heat exchanger (27) and a regenerative heat exchanger (43) serve as evaporators. A pressure adjustment mechanism (44) is configured so as to be capable of adjusting the pressure of the refrigerant flowing between the regenerative heat exchanger (43) and the gas refrigerant flow path (13).

Description

Thermal storage air conditioner

This disclosure relates to a regenerative air conditioner.

As shown in Patent Document 1, a regenerative air conditioner that performs indoor air conditioning using a heat storage medium as a cold source is known. In Patent Document 1, a heat storage heat exchanger having a flow path through which a refrigerant passes is disposed in a heat storage tank that stores the heat storage medium, and the heat storage medium is cooled by the refrigerant. As the heat storage medium, a heat storage material (for example, an aqueous solution of tetra-n-butylammonium bromide) in which clathrate hydrate is generated by cooling is used. Moreover, in the heat storage type air conditioner of patent document 1, the air_conditioning | cooling storage operation which performs air_conditioning | cooling, storing cold heat is performed.

JP 2007-17089 A

By the way, in the heat storage type air conditioner shown in Patent Document 1, the heat storage heat exchanger is installed outside the heat storage tank (heat storage tank), and the heat storage medium circulates between the heat storage heat exchanger and the heat storage tank. It is conceivable to construct a heat storage circuit that performs this. In such a configuration, when the cooling storage operation is performed, the heat storage medium flowing into the heat storage heat exchanger from the heat storage tank absorbs heat into the refrigerant flowing through the heat storage heat exchanger while passing through the heat storage heat exchanger. To be cooled.

Further, in the above-described configuration, in the cooling storage operation, in order to secure the cooling capacity (that is, the cooling capacity) in the indoor heat exchanger, the suction pressure of the compressor is reduced to evaporate the refrigerant in the indoor heat exchanger. It is conceivable to reduce the pressure. For example, when the pressure loss between the gas end of the indoor heat exchanger and the suction end of the compressor is large (specifically, the piping between the gas end of the indoor heat exchanger and the suction end of the compressor is long) Or when the difference in elevation between the gas end of the indoor heat exchanger and the suction end of the compressor is large), the refrigerant evaporating pressure in the indoor heat exchanger is set to the evaporating pressure necessary for ensuring cooling capacity. Therefore, the suction pressure of the compressor is set low. Further, when the indoor cooling load increases and the cooling capacity is insufficient, the suction pressure of the compressor is lowered in order to reduce the evaporation pressure of the refrigerant in the indoor heat exchanger.

However, if the suction pressure of the compressor is reduced to reduce the evaporation pressure of the refrigerant in the indoor heat exchanger, the evaporation pressure of the refrigerant in the heat storage heat exchanger decreases as the suction pressure of the compressor decreases. As a result, the evaporation temperature of the refrigerant decreases. Therefore, the heat storage medium is excessively cooled in the heat storage heat exchanger, and a large amount of clathrate hydrate (solid component) is generated. As a result, the circulation efficiency of the heat storage medium in the heat storage circuit may be reduced.

Therefore, the present disclosure aims to provide a regenerative air conditioner that can suppress a decrease in circulation efficiency of a heat storage medium while ensuring cooling capacity in a cooling and regenerating operation.

The first aspect of the present disclosure includes a compressor (21), an outdoor heat exchanger (22), an indoor heat exchanger (27), a liquid end of the outdoor heat exchanger (22), and the indoor heat exchange. A liquid refrigerant channel (12) to which the liquid end of the heat exchanger (27) is connected, a gas refrigerant channel (13) to which the gas end of the indoor heat exchanger (27) is connected, and one end of the liquid refrigerant flow A refrigerant circuit (11) having a bypass channel (14) connected to the channel (12) and having the other end connected to the gas refrigerant channel (13) and a heat storage medium in which a solid component is generated by cooling flow. The heat storage circuit (31), the bypass flow path (14), and the heat storage circuit (31) are connected to the refrigerant flow through the bypass flow path (14) and the heat storage medium flowing through the heat storage circuit (31). The heat storage heat exchanger (43) to be exchanged, and the pressure provided between the heat storage heat exchanger (43) and the gas refrigerant channel (13) in the bypass channel (14) An adjustment mechanism (44), and in the refrigerant circuit (11), the discharge end of the compressor (21) is connected to the gas end of the outdoor heat exchanger (22), and the suction of the compressor (21) An end is connected to the gas refrigerant flow path (13), the outdoor heat exchanger (22) serves as a condenser, and the indoor heat exchanger (27) and the heat storage heat exchanger (43) serve as an evaporator. A cold storage cycle is performed, and the pressure adjusting mechanism (44) is configured to be able to adjust the pressure of the refrigerant flowing between the heat storage heat exchanger (43) and the gas refrigerant flow path (13). Is a regenerative air conditioner.

In the first aspect, by providing the pressure adjustment mechanism (44), in the cooling and accumulating operation (that is, in the case where the cooling and accumulating cycle is performed in the refrigerant circuit (11)), the suction pressure of the compressor (21) is more than The evaporating pressure of the refrigerant in the heat storage heat exchanger (43) can be adjusted to be higher. Thereby, the fall of the evaporating pressure of the refrigerant | coolant in the heat storage heat exchanger (43) accompanying the fall of the suction pressure of a compressor (21) can be suppressed, and the evaporating temperature of the refrigerant | coolant in the heat storage heat exchanger (43) Can be prevented from becoming too low. Therefore, it is possible to prevent the heat storage medium from being overcooled in the heat storage heat exchanger (43).

According to a second aspect of the present disclosure, in the first aspect, the refrigerant circuit (11) is controlled so that the cooling and regenerating cycle is performed, and the evaporation temperature of the refrigerant in the heat storage heat exchanger (43) is set. The regenerative air conditioner further includes an operation control unit (100) for adjusting a pressure reduction amount in the pressure adjusting mechanism (44) so as not to fall below a preset lower limit evaporation temperature.

In the second aspect, the evaporation pressure of the refrigerant in the heat storage heat exchanger (43) can be set appropriately. Thereby, a heat storage medium can be cooled appropriately in the heat storage heat exchanger (43).

According to a third aspect of the present disclosure, in the first or second aspect, the bypass flow path (14) connects the heat storage heat exchanger (43) and the gas refrigerant flow path (13). A pressure control valve (45) having a first flow path part (14d), the pressure control mechanism (44) being configured to be able to adjust the opening thereof and provided in the first flow path part (14d) It is a thermal storage type air conditioner characterized by having.

In the third aspect, the amount of pressure reduction in the pressure adjusting mechanism (44) can be adjusted by adjusting the opening of the pressure adjusting valve (45). Thereby, the evaporation pressure of the refrigerant in the heat storage heat exchanger (43) can be adjusted to be higher than the suction pressure of the compressor (21), and the heat storage medium is cooled in the heat storage heat exchanger (43). It is possible to prevent being overdone.

According to a fourth aspect of the present disclosure, in the third aspect, the bypass flow path (14) is provided in parallel with the first flow path portion (14d), and the heat storage heat exchanger (43) The second flow path part (14e) connecting the gas refrigerant flow path (13) is further provided, and the pressure adjusting mechanism (44) is configured to be able to switch between opening and closing thereof, and the second flow path part ( The regenerative air conditioner further includes an on-off valve (46) provided in 14e).

In the fourth aspect, the on-off valve (46) is set in an open state and the pressure regulating valve (45) is set in a fully closed state, whereby a heat storage heat exchanger ( 43) and the gas refrigerant channel (13) can be circulated. Note that the pressure loss in the on-off valve (46) is smaller than the pressure loss in the pressure control valve (45). Therefore, the pressure loss in the pressure control mechanism (44) is less than when the refrigerant is circulated between the heat storage heat exchanger (43) and the gas refrigerant flow path (13) via the pressure control valve (45). Can be reduced. Thereby, the pressure loss in the pressure adjustment mechanism (44) can be reduced in another operation different from the cooling / storage operation.

According to the first and third aspects, it is possible to prevent the heat storage medium from being excessively cooled in the heat storage heat exchanger (43), so that in the cooling and cold storage operation, the cooling capacity in the indoor heat exchanger (that is, It is possible to suppress a decrease in the circulation efficiency of the heat storage medium in the heat storage circuit (31) while ensuring (cooling capacity).

According to the second aspect, since the heat storage medium can be appropriately cooled in the heat storage heat exchanger (43), cold storage can be appropriately performed in the cooling and cold storage operation.

According to the fourth aspect, since the pressure loss in the pressure adjustment mechanism (44) can be reduced in another operation different from the cooling and regenerating operation, the other operation can be appropriately performed.

FIG. 1 is a configuration diagram of a heat storage type air conditioner. FIG. 2 is a diagram illustrating the refrigerant flow during the simple cooling operation. FIG. 3 is a diagram illustrating the flow of the refrigerant during the simple heating operation. FIG. 4 is a diagram illustrating the flow of the refrigerant and the heat storage medium during the cold storage operation. FIG. 5 is a diagram illustrating the flows of the refrigerant and the heat storage medium during the use cooling operation. FIG. 6 is a diagram illustrating the flows of the refrigerant and the heat storage medium during the cooling and storing operation.

Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Regenerative air conditioner)
Drawing 1 shows the example of composition of the heat storage type air harmony machine (10) by an embodiment. The heat storage type air conditioner (10) is composed of an outdoor unit (20a), an indoor unit (20b), and a heat storage unit (30). The refrigerant circuit (11), the heat storage circuit (31), and the preheat heat exchanger ( 41), a heat storage expansion valve (42), a heat storage heat exchanger (43), a pressure adjusting mechanism (44), and a controller (100).

[Refrigerant circuit]
The refrigerant circuit (11) is filled with a refrigerant. And in a refrigerant circuit (11), a refrigerating cycle is performed when a refrigerant circulates. The refrigerant circuit (11) includes a compressor (21), an outdoor heat exchanger (22), an outdoor expansion valve (23), an outdoor subcooling heat exchanger (24), and a heat storage side subcooling heat exchanger. (25), an indoor expansion valve (26), an indoor heat exchanger (27), and a four-way switching valve (28). Furthermore, the refrigerant circuit (11) has a liquid refrigerant channel (12), a gas refrigerant channel (13), a bypass channel (14), and a branch channel (15).

The outdoor unit (20a) is installed outside the room. The outdoor unit (20a) is provided with a compressor (21), an outdoor heat exchanger (22), an outdoor expansion valve (23), an outdoor supercooling heat exchanger (24), and a four-way switching valve (28). ing. The outdoor unit (20a) is provided with an outdoor fan (22a) for conveying air to the outdoor heat exchanger (22).

The indoor unit (20b) is installed indoors. The indoor unit (20b) is provided with an indoor expansion valve (26) and an indoor heat exchanger (27). The indoor unit (20b) is provided with an indoor fan (27a) for conveying air to the indoor heat exchanger (27).

The heat storage unit (30) is connected between the outdoor unit (20a) and the indoor unit (20b), and is installed in the vicinity of the outdoor unit (20a). The heat storage unit (30) includes a heat storage side subcooling heat exchanger (25), a heat storage circuit (31), a preheating heat exchanger (41), a heat storage expansion valve (42), and a heat storage heat exchanger (43). And a pressure adjusting mechanism (44).

<Compressor>
The compressor (21) has a discharge end connected to the first port of the four-way switching valve (28) and a suction end connected to the second port of the four-way switching valve (28). The compressor (21) compresses and discharges the sucked refrigerant. Furthermore, the compressor (21) is configured to be able to change its capacity (rotation speed). For example, the compressor (21) is constituted by a variable capacity compressor, and the rotation speed (operation frequency) is changed by an inverter circuit (not shown).

<Outdoor heat exchanger>
The outdoor heat exchanger (22) has a gas end connected to the third port of the four-way switching valve (28) by the first refrigerant pipe (11a), and a liquid end flowing through the second refrigerant pipe (11b). Connected to one end of the path (12). The second refrigerant pipe (11b) includes an outdoor expansion valve (23) and an outdoor subcooling heat exchanger from the liquid end of the outdoor heat exchanger (22) to one end of the liquid refrigerant flow path (12). (24) and are provided in order. That is, the liquid end of the outdoor heat exchanger (22) is connected to the liquid refrigerant flow path (12) through the outdoor expansion valve (23) and the outdoor subcooling heat exchanger (24) in this order. The outdoor heat exchanger (22) exchanges heat between the outdoor air conveyed by the outdoor fan (22a) and the refrigerant. For example, the outdoor heat exchanger (22) is configured by a cross fin and tube heat exchanger.

<Outdoor expansion valve>
The outdoor expansion valve (23) is configured to be adjustable in its opening, and the pressure and flow rate of the refrigerant are adjusted by adjusting the opening. For example, the outdoor expansion valve (23) is constituted by an electronic expansion valve (motorized valve).

<Outdoor undercooling heat exchanger>
The outdoor supercooling heat exchanger (24) has a high-pressure side passage (24a) and a low-pressure side passage (24b). The high-pressure side passage (24a) is inserted (connected) in series with the second refrigerant pipe (11b). The low-pressure side passage (24b) is inserted in series with the auxiliary pipe (24d). One end of the auxiliary pipe (24d) is connected to a midway portion located between the outdoor expansion valve (23) of the second refrigerant pipe (11b) and the outdoor subcooling heat exchanger (24), and the other end is connected. Connected to the suction end of the compressor (21). The outdoor supercooling heat exchanger (24) heat-exchanges the refrigerant flowing through the high pressure side passage (24a) by exchanging heat between the refrigerant flowing through the high pressure side passage (24a) and the refrigerant flowing through the low pressure side passage (24b). It is configured to cool. The auxiliary pipe (24d) is provided with an outdoor supercooling expansion valve (24c) for adjusting the flow rate of the refrigerant flowing through the low pressure side passage (24b).

<Heat storage side subcooling heat exchanger>
The heat storage side subcooling heat exchanger (25) is provided in the liquid refrigerant flow path (12). In this example, the heat storage side subcooling heat exchanger (25) is disposed near the other end of the liquid refrigerant channel (12). The heat storage side subcooling heat exchanger (25) has a high pressure side passage (25a) and a low pressure side passage (25b). The high-pressure side passage (25a) is inserted in series with the liquid refrigerant passage (12). The low-pressure side passage (25b) is inserted in series with the auxiliary pipe (25d). One end of the auxiliary pipe (25d) is in the middle of the liquid refrigerant channel (12) (middle part located between one end of the liquid refrigerant channel (12) and the heat storage side subcooling heat exchanger (25)) The other end is connected to the gas refrigerant channel (13). The heat storage side subcooling heat exchanger (25) heat-exchanges the refrigerant flowing through the high pressure side passage (25a) by exchanging heat between the refrigerant flowing through the high pressure side passage (25a) and the refrigerant flowing through the low pressure side passage (25b). It is configured to cool. The auxiliary pipe (25d) is provided with a heat storage side subcooling expansion valve (25c) for adjusting the flow rate of the refrigerant flowing through the low pressure side passage (25b).

<Indoor expansion valve>
The indoor expansion valve (26) is provided in the third refrigerant pipe (11c) that connects the other end of the liquid refrigerant channel (12) and the liquid end of the indoor heat exchanger (27). Further, the indoor expansion valve (26) is configured to be able to adjust its opening, and the refrigerant pressure and flow rate are adjusted by adjusting the opening. For example, the indoor expansion valve (26) is configured by an electronic expansion valve (motorized valve).

<Indoor heat exchanger>
The indoor heat exchanger (27) has a liquid end connected to the other end of the liquid refrigerant flow path (12) by the third refrigerant pipe (11c), and a gas end connected to the gas refrigerant flow by the fourth refrigerant pipe (11d). Connected to one end of the path (13). That is, the liquid end of the indoor heat exchanger (27) is connected to the liquid refrigerant channel (12) via the indoor expansion valve (26). The indoor heat exchanger (27) exchanges heat between the indoor air conveyed by the indoor fan (27a) and the refrigerant. The indoor air heat-exchanged in the indoor heat exchanger (27) is supplied again into the room. For example, the indoor heat exchanger (27) is configured by a cross fin and tube heat exchanger.

<4-way switching valve>
The four-way switching valve (28) determines the connection state of the first to fourth ports according to the operation type of the regenerative air conditioner (10) in the first state (the state indicated by the solid line in FIG. 1) and the second state ( The state indicated by the broken line in FIG. 1 is switchable. The fourth port of the four-way switching valve (28) is connected to the other end of the gas refrigerant flow path (13) by the fifth refrigerant pipe (11e).

<Bypass channel>
The bypass channel (14) has one end connected to the liquid refrigerant channel (12) and the other end connected to the gas refrigerant channel (13). Further, the bypass channel (14) is directed from one end side (that is, liquid refrigerant channel (12) side) to the other end side (that is, gas refrigerant channel (13) side) of the bypass channel (14). Thus, a preheating heat exchanger (41), a heat storage expansion valve (42), a heat storage heat exchanger (43), and a pressure adjusting mechanism (44) are sequentially provided.

In the liquid refrigerant channel (12), the connection point (first connection point (P1)) between the bypass channel (14) and the liquid refrigerant channel (12) is the heat storage side subcooling heat exchanger (25). One end side of the liquid refrigerant flow path (12) from the connection point (second connection point (P2)) between the auxiliary pipe (25d) and the liquid refrigerant flow path (12) (that is, the second refrigerant pipe (11b)) Side). In this example, the bypass channel (14) includes the first main pipe (14a), the second main pipe (14b), the third main pipe (14c), the first branch pipe (14d), and the second branch pipe. (14e). The first main pipe (14a) connects the midway part of the liquid refrigerant flow path (12) and the preheating heat exchanger (41). The second main pipe (14b) connects the preheating heat exchanger (41) and the heat storage heat exchanger (43). One end of the third main pipe (14c) is connected to the heat storage heat exchanger (43). The first branch pipe (14d) connects the other end of the third main pipe (14c) and the gas refrigerant channel (13). The second branch pipe (14e) is provided in parallel with the first branch pipe (14d) and connects the third main pipe (14c) and the gas refrigerant channel (13). That is, the first branch pipe (14d) constitutes a pipe (first flow path portion) that connects the heat storage heat exchanger (43) and the gas refrigerant flow path (13). The second branch pipe (14e) is provided in parallel with the first branch pipe (14d) and connects the heat storage heat exchanger (43) and the gas refrigerant flow path (13) (second flow path portion). Is configured.

<Branch channel>
One end of the branch channel (15) is connected to the midway part of the bypass channel (14) (the midway part located between the heat storage heat exchanger (43) and the pressure control mechanism (44)). The end is connected to a midway part (midway part located between the first connection point (P1) and the second connection point (P2)) of the liquid refrigerant flow path (12). That is, in the liquid refrigerant flow path (12), the connection point (third connection point (P3)) between the branch flow path (15) and the liquid refrigerant flow path (12) is the first connection point (P1) and the second connection point. It is located between the connection point (P2).

<Open / close valve and check valve>
The refrigerant circuit (11) includes a first on-off valve (51), a second on-off valve (52), a third on-off valve (53), a first check valve (51a), and a second check valve ( 51b) and a third check valve (51c) are provided. For example, the first on-off valve (51), the second on-off valve (52), and the third on-off valve (53) are constituted by electromagnetic valves.

The first on-off valve (51) is provided between the first connection point (P1) and the second connection point (P2) in the liquid refrigerant channel (12). The first check valve (51a) is connected in parallel with the first on-off valve (51). The first check valve (51a) is configured to flow the refrigerant from the heat storage side subcooling heat exchanger (25) side toward the outdoor side subcooling heat exchanger (24) side in the simple heating operation described later. Has been.

The second on-off valve (52) is connected in parallel with the heat storage expansion valve (42). The second check valve (51b) is connected in series with the second on-off valve (52) and is in parallel with the heat storage expansion valve (42). The second check valve (51b) allows only the refrigerant flow from the preheating heat exchanger (41) side to the heat storage heat exchanger (43) side.

The third on-off valve (53) is provided in the branch channel (15). The third check valve (51c) is provided in the branch channel (15) and allows only the refrigerant flow from the bypass channel (14) side to the liquid refrigerant channel (12) side.

[Heat exchanger for preheating]
The preheating heat exchanger (41) is connected to the bypass passage (14) and the heat storage circuit (31) of the refrigerant circuit (11), and flows through the refrigerant flowing through the bypass passage (14) and the heat storage circuit (31). Heat exchange with the heat storage medium. Specifically, the preheating heat exchanger (41) includes a refrigerant side passage (41a) and a heat storage side passage (41b). The refrigerant side passage (41a) is inserted in series with the bypass passage (14). In this example, the refrigerant side passage (41a) is connected between the first main pipe (14a) and the second main pipe (14b) of the bypass flow path (14). The heat storage side passage (41b) is inserted in series with the heat storage circuit (31). The preheating heat exchanger (41) exchanges heat between the refrigerant flowing through the refrigerant side passage (41a) and the heat storage medium flowing through the heat storage side passage (41b).

[Expansion valve for heat storage]
The heat storage expansion valve (42) is provided between the preheating heat exchanger (41) and the heat storage heat exchanger (43) in the bypass passage (14). In this example, the heat storage expansion valve (42) is provided in the second main pipe (14b) of the bypass flow path (14). Further, the heat storage expansion valve (42) is configured such that its opening degree can be adjusted, and the refrigerant pressure and flow rate are adjusted by adjusting the opening degree. For example, the heat storage expansion valve (42) is constituted by an electromagnetic expansion valve (motor valve).

Also, a pressure relief valve (42a) is connected in parallel to the heat storage expansion valve (42). The pressure relief valve (42a) is, for example, a heat storage heat exchanger (43) when the pressure on the heat storage heat exchanger (43) side exceeds an allowable value when the heat storage air conditioner (10) is stopped. ) A valve for releasing the pressure on the side.

[Heat exchanger for heat storage]
The heat storage heat exchanger (43) is connected to the bypass flow path (14) and the heat storage circuit (31) of the refrigerant circuit (11), and flows through the refrigerant flowing through the bypass flow path (14) and the heat storage circuit (31). Heat exchange with the heat storage medium. Specifically, the heat storage heat exchanger (43) includes a refrigerant side passage (43a) and a heat storage side passage (43b). The refrigerant side passage (43a) is inserted in series in the bypass passage (14). In this example, the refrigerant side passage (43a) is connected between the second main pipe (14b) and the third main pipe (14c) of the bypass flow path (14). The heat storage side passage (43b) is inserted in series with the heat storage circuit (31). The heat storage heat exchanger (43) exchanges heat between the refrigerant flowing through the refrigerant side passage (43a) and the heat storage medium flowing through the heat storage side passage (43b).

(Pressure adjustment mechanism)
The pressure adjusting mechanism (44) is provided between the heat storage heat exchanger (43) and the gas refrigerant channel (13) in the bypass channel (14). The pressure adjusting mechanism (44) is configured to be able to adjust the pressure of the refrigerant flowing between the heat storage heat exchanger (43) and the gas refrigerant flow path (13).

In this example, the pressure adjusting mechanism (44) has a pressure adjusting valve (45) and a flow path opening / closing valve (46). The pressure control valve (45) is provided in the first branch pipe (14d) of the bypass channel (14). Moreover, the pressure control valve (45) is comprised so that adjustment of the opening degree is possible. For example, the pressure control valve (45) is an electric valve. The flow path opening / closing valve (46) is provided in the second branch pipe (14e) of the bypass flow path (14). The flow path opening / closing valve (46) is configured to be able to switch between opening and closing. For example, the flow path opening / closing valve (46) is constituted by an electromagnetic valve.

[Heat storage circuit]
The heat storage circuit (31) is filled with a heat storage medium. In the heat storage circuit (31), a circulation operation for circulating the heat storage medium is performed. The heat storage circuit (31) includes a heat storage tank (32) and a circulation pump (33).

<Heat storage tank>
The heat storage tank (32) is a hollow container and stores a heat storage medium. For example, the heat storage tank (32) is formed in a cylindrical shape closed at both ends, and is arranged so that its axial direction is the vertical direction. The heat storage tank (32) is formed with an outlet and an inlet, and the outlet is located above the inlet, for example.

<Circulation pump>
The circulation pump (33) circulates the heat storage medium among the heat storage tank (32), the preheating heat exchanger (41), and the heat storage heat exchanger (43) in the heat storage circuit (31). The circulation direction of the heat storage medium is as follows. That is, the heat storage medium that has flowed out of the heat storage tank (32) passes through the heat storage side passage (41b) of the preheating heat exchanger (41), passes through the circulation pump (33), and then passes through the heat storage heat exchanger ( It passes through the heat storage side passage (43b) of 43) and flows into the heat storage tank (32). The controller (100) controls on / off of the operation of the circulation pump (33) and the flow rate of the heat storage medium conveyed by the circulation pump (33).

[Heat storage medium]
Here, the heat storage medium will be described. As the heat storage medium, a heat storage material in which a solid component is generated by cooling (more specifically, a heat storage material in which a solid component is generated at a temperature higher than 0 ° C. and lower than 20 ° C. by cooling) is employed. The solid component refers to a component that has undergone phase transition (latent heat change) from a liquid at its melting point and is in an exothermic state. Specific examples of the solid component include clathrate hydrate.

Hereinafter, a case where a heat storage material in which clathrate hydrate is generated by cooling (that is, a heat storage material having fluidity) is employed as a heat storage medium will be described as an example. Specific examples of such a heat storage medium include tetranbutylammonium bromide (TBAB) aqueous solution, tetramethylolethane (TME) aqueous solution, paraffinic slurry and the like containing tetra nbutylammonium bromide. Can be mentioned. For example, an aqueous solution of tetra-n-butylammonium bromide maintains the state of the aqueous solution even in a supercooled state in which the aqueous solution is cooled stably and the temperature of the aqueous solution becomes lower than the hydrate formation temperature. When given some trigger, the supercooled solution transitions to a solution containing clathrate hydrate (ie, slurry). That is, the tetra-n-butylammonium bromide aqueous solution eliminates the supercooled state, and clathrate hydrates (hydrate crystals) composed of tetra-n-butylammonium bromide and water molecules are generated, resulting in a relatively viscous viscosity. It becomes a high slurry state. Here, the supercooled state refers to a state where the clathrate hydrate is not generated and the state of the solution is maintained even when the heat storage medium becomes a temperature lower than the hydrate generation temperature. Conversely, when the aqueous solution of tetra-n-butylammonium bromide in a slurry state is heated, the temperature of the aqueous solution becomes higher than the hydrate formation temperature, the clathrate hydrate melts and the fluidity is relatively high. It becomes a liquid state (solution).

In this embodiment, a tetra-n-butylammonium bromide aqueous solution containing tetra-n-butylammonium bromide is employed as the heat storage medium. In particular, the heat storage medium is preferably a medium having a concentration near the harmonic concentration. The harmonic concentration means a concentration at which the concentration of the aqueous solution does not change before and after the clathrate hydrate is formed. In this embodiment, the harmonic concentration is about 40%. In this case, the hydrate formation temperature of the aqueous solution of tetra-n-butylammonium bromide is about 12 ° C.

Note that the hydrate formation temperature of the tetra n-butylammonium bromide aqueous solution varies depending on the concentration of the heat storage medium. For example, when the concentration of the heat storage medium is about 20%, the hydrate formation temperature is about 8.5 ° C.

(Refrigerant temperature sensor)
The regenerative air conditioner (10) is provided with various sensors such as a first refrigerant temperature sensor (61) and a second refrigerant temperature sensor (62).

The first refrigerant temperature sensor (61) detects the refrigerant temperature (first refrigerant temperature) on one end side (gas refrigerant flow path (13) side) of the heat storage heat exchanger (43). In this example, the first refrigerant temperature sensor (61) is installed in the vicinity of one end of the refrigerant side passage (43a) of the heat storage heat exchanger (43), and detects the refrigerant temperature at the installation location as the first refrigerant temperature. .

The second refrigerant temperature sensor (62) detects the refrigerant temperature (second refrigerant temperature) on the other end side (liquid refrigerant flow path (12) side) of the heat storage heat exchanger (43). In this example, the second refrigerant temperature sensor (62) is installed in the vicinity of the other end of the refrigerant side passage (43a) of the heat storage heat exchanger (43), and detects the refrigerant temperature at the installation location as the second refrigerant temperature. To do.

[Controller (operation control unit)]
A controller (100) controls each operation | movement of a thermal storage type air conditioner (10) by controlling each part of a thermal storage type air conditioner (10) based on the detected value of various sensors. In this heat storage type air conditioner (10), simple cooling operation, simple heating operation, cold storage operation, utilization cooling operation, and cooling cold storage operation are performed.

[Simple cooling operation]
Next, the simple cooling operation will be described with reference to FIG. The simple cooling operation is an operation in which indoor cooling is performed using only the cooling heat obtained by the refrigeration cycle of the refrigerant circuit (11).

In the refrigerant circuit (11), a refrigeration cycle (simple cooling cycle) in which the outdoor heat exchanger (22) serves as a condenser and the indoor heat exchanger (27) serves as an evaporator is performed. On the other hand, in the heat storage circuit (31), the heat storage medium does not circulate.

Specifically, the four-way selector valve (28) is set to the first state. Thereby, as for the compressor (21), the discharge end is connected to the gas end of an outdoor heat exchanger (22), and the suction | inhalation end is connected to a gas refrigerant flow path (13). Further, the first on-off valve (51) is set in the open state, and the second on-off valve (52) and the third on-off valve (53) are set in the closed state. The opening of the outdoor expansion valve (23) is set to a fully open state, and the opening of the indoor expansion valve (26) is set to a predetermined opening (the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (27) is the target superheat degree). The opening degree of the heat storage expansion valve (42) is set to a fully closed state. The opening degree of the outdoor supercooling expansion valve (24c) is adjusted to a predetermined opening degree, and the opening degree of the heat storage side supercooling expansion valve (25c) is set to a fully closed state. The opening degree of the pressure control valve (45) is set to a fully closed state, and the flow path opening / closing valve (46) is set to an open state. Then, the compressor (21), the outdoor fan (22a), and the indoor fan (27a) are set to the drive state, and the circulation pump (33) is set to the stop state. These settings and adjustments are performed in response to control by the controller (100). The same applies to the following description.

The refrigerant discharged from the compressor (21) flows into the outdoor heat exchanger (22), dissipates heat to the outdoor air and condenses in the outdoor heat exchanger (22). The refrigerant that has flowed out of the outdoor heat exchanger (22) passes through the fully-expanded outdoor expansion valve (23) and flows into the outdoor subcooling heat exchanger (24), and the outdoor subcooling heat exchanger (24). Cooled. The refrigerant that has flowed out of the outdoor supercooling heat exchanger (24) sequentially passes through the first open / close valve (51) and the heat storage side supercooling heat exchanger (25) in the liquid refrigerant flow path (12). Flows into the indoor expansion valve (26) and is depressurized in the indoor expansion valve (26). The refrigerant that has passed through the indoor expansion valve (26) flows into the indoor heat exchanger (27), absorbs heat from the indoor air in the indoor heat exchanger (27), and evaporates. Thereby, indoor air is cooled. The refrigerant that has flowed out of the indoor heat exchanger (27) passes through the gas refrigerant channel (13), is sucked into the compressor (21), and is compressed again.

In addition, since the flow path on-off valve (46) of the pressure adjusting mechanism (44) is set to the open state, the refrigerant is prevented from collecting in the refrigerant side passage (43a) of the heat storage heat exchanger (43). be able to.

[Simple heating operation]
Next, the simple heating operation will be described with reference to FIG. The simple heating operation is an operation for heating the room using only the heat obtained by the refrigeration cycle of the refrigerant circuit (11).

In the refrigerant circuit (11), a refrigeration cycle (simple heating cycle) is performed in which the indoor heat exchanger (27) serves as a condenser and the outdoor heat exchanger (22) serves as an evaporator. On the other hand, in the heat storage circuit (31), the heat storage medium does not circulate.

Specifically, the four-way selector valve (28) is set to the second state. Thereby, the discharge end of the compressor (21) is connected to the gas refrigerant flow path (13), and the suction end thereof is connected to the gas end of the outdoor heat exchanger (22). Further, the first on-off valve (51), the second on-off valve (52), and the third on-off valve (53) are set in a closed state. The opening degree of the outdoor expansion valve (23) is adjusted to a predetermined opening degree (the opening degree at which the refrigerant superheat degree at the outlet of the outdoor heat exchanger (22) becomes the target superheat degree), and the indoor expansion valve (26) is opened. The degree of opening is adjusted to a predetermined opening (the opening at which the degree of refrigerant subcooling at the outlet of the indoor heat exchanger (27) becomes the target subcooling degree), and the opening of the heat storage expansion valve (42) is fully closed Set to The opening degree of the outdoor supercooling expansion valve (24c) is set to a fully closed state, and the opening degree of the heat storage side supercooling expansion valve (25c) is set to a fully closed state. The opening degree of the pressure control valve (45) is set to a fully closed state, and the flow path opening / closing valve (46) is set to a closed state. The compressor (21), the outdoor fan (22a), and the indoor fan (27a) are set to the drive state, and the circulation pump (33) is set to the stop state.

The refrigerant discharged from the compressor (21) passes through the gas refrigerant flow path (13), flows into the indoor heat exchanger (27), and dissipates heat to the indoor air and condenses in the indoor heat exchanger (27). . Thereby, indoor air is heated. The refrigerant flowing out of the indoor heat exchanger (27) passes through the indoor expansion valve (26), and in the liquid refrigerant flow path (12), the heat storage side subcooling heat exchanger (25) and the third connection point (P3) It passes through the first check valve (51a) and the first connection point (P1) in order, passes through the outdoor supercooling heat exchanger (24), and is depressurized in the outdoor expansion valve (23). The refrigerant that has passed through the outdoor expansion valve (23) flows into the outdoor heat exchanger (22), and absorbs heat from outdoor air and evaporates in the outdoor heat exchanger (22). The refrigerant flowing out of the outdoor heat exchanger (22) is sucked into the compressor (21) and compressed again.

(Cool storage operation)
Next, the cold storage operation will be described with reference to FIG. The cold storage operation is an operation in which cold heat obtained by the refrigeration cycle of the refrigerant circuit (11) is stored in the heat storage tank (32) of the heat storage circuit (31).

In the refrigerant circuit (11), the outdoor heat exchanger (22) serves as a condenser and the preheating heat exchanger (41) serves as a subcooler and the heat storage heat exchanger (43) serves as an evaporator (cold storage cycle). Is done. On the other hand, in the heat storage circuit (31), a circulation operation (an operation for circulating the heat storage medium) is performed.

Specifically, the four-way selector valve (28) is set to the first state. Thereby, as for the compressor (21), the discharge end is connected to the gas end of an outdoor heat exchanger (22), and the suction | inhalation end is connected to a gas refrigerant flow path (13). Further, the first on-off valve (51) is set in the open state, and the second on-off valve (52) and the third on-off valve (53) are set in the closed state. The opening of the outdoor expansion valve (23) is set to a fully open state, the opening of the indoor expansion valve (26) is set to a fully closed state, and the opening of the heat storage expansion valve (42) is set to a predetermined opening (heat storage). The degree of opening at which the refrigerant evaporating temperature at the outlet of the heat exchanger becomes the target evaporating temperature is adjusted. The opening degree of the outdoor supercooling expansion valve (24c) is set to a fully closed state, and the opening degree of the heat storage side supercooling expansion valve (25c) is set to a fully closed state. The opening degree of the pressure control valve (45) is set to a fully closed state, and the flow path opening / closing valve (46) is set to an open state. The compressor (21) and the outdoor fan (22a) are set to the drive state, the indoor fan (27a) is set to the stop state, and the circulation pump (33) is set to the drive state. The compressor (21) operates at a substantially constant rotational speed.

The refrigerant discharged from the compressor (21) flows into the outdoor heat exchanger (22), dissipates heat to the outdoor air and condenses in the outdoor heat exchanger (22). The refrigerant flowing out of the outdoor heat exchanger (22) sequentially passes through the fully opened outdoor expansion valve (23) and the outdoor subcooling heat exchanger (24) and flows into the liquid refrigerant flow path (12). The refrigerant flowing into the liquid refrigerant channel (12) passes through the first connection point (P1) and flows into the bypass channel (14). The refrigerant flowing into the bypass channel (14) flows into the refrigerant side passage (41a) of the preheating heat exchanger (41) and passes through the refrigerant side passage (41a) of the preheating heat exchanger (41). The heat is transferred to the heat storage medium flowing through the heat storage side passage (41b) and cooled. The refrigerant flowing out from the refrigerant side passage (41a) of the preheating heat exchanger (41) is decompressed in the heat storage expansion valve (42) and flows into the refrigerant side passage (43a) of the heat storage heat exchanger (43). Then, while passing through the refrigerant side passage (43a) of the heat storage heat exchanger (43), the heat is absorbed from the heat storage medium flowing through the heat storage side passage (43b) and evaporated. The refrigerant flowing out from the refrigerant side passage (43a) of the heat storage heat exchanger (43) sequentially passes through the open channel on-off valve (46) and the gas refrigerant channel (13) of the pressure adjustment mechanism (44). Then, it is sucked into the compressor (21) and compressed again.

In addition, since the 1st on-off valve (51) is set to the open state, it is liquid in the piping part (liquid pipe) from the 1st connection point (P1) of a bypass flow path (14) to an indoor expansion valve (26). The refrigerant will accumulate. Thereby, since the state of the refrigerant | coolant in this piping part can be made into the state similar to a simple cooling operation, generation | occurrence | production of an excess refrigerant | coolant can be prevented.

In the heat storage circuit (31), the heat storage medium flowing out of the heat storage tank (32) flows into the heat storage side passage (41b) of the preheating heat exchanger (41), and the heat storage side passage of the preheating heat exchanger (41). Heated by the refrigerant flowing through the refrigerant side passage (41a) while passing through (41b). The heat storage medium flowing out from the heat storage side passage (41b) of the preheating heat exchanger (41) passes through the circulation pump (33) and flows into the heat storage side passage (43b) of the heat storage heat exchanger (43), Cooling is performed by the refrigerant flowing through the refrigerant side passage (43a) while passing through the heat storage side passage (43b) of the heat storage heat exchanger (43). The heat storage medium that has flowed out of the heat storage side passage (43b) of the heat storage heat exchanger (43) flows into the heat storage tank (32). In this way, cold heat is stored in the heat storage tank (32).

[Use cooling operation]
Next, referring to FIG. 5, the use cooling operation will be described. The use cooling operation is an operation for cooling the room using the cold heat stored in the heat storage tank (32) and the cold heat obtained by the refrigeration cycle of the refrigerant circuit (11).

In the refrigerant circuit (11), the outdoor heat exchanger (22) serves as a condenser, the preheating heat exchanger (41) and the heat storage heat exchanger (43) serve as a subcooler, and the indoor heat exchanger (27) serves as an evaporator. A refrigeration cycle (utilization cooling cycle) is performed. On the other hand, the circulation operation is performed in the heat storage circuit (31).

Specifically, the four-way selector valve (28) is set to the first state. Thereby, as for the compressor (21), the discharge end is connected to the gas end of an outdoor heat exchanger (22), and the suction | inhalation end is connected to a gas refrigerant flow path (13). Further, the first on-off valve (51) is set in a closed state, and the second on-off valve (52) and the third on-off valve (53) are set in an open state. The opening degree of the outdoor expansion valve (23) is set to a fully open state, and the opening degree of the indoor expansion valve (26) is a predetermined opening degree (an opening degree at which the superheat degree of the refrigerant at the outlet of the indoor heat exchanger becomes the target superheat degree. ) And the opening degree of the heat storage expansion valve (42) is set to a fully open state. The opening degree of the outdoor supercooling expansion valve (24c) is set to a fully closed state, and the opening degree of the heat storage side supercooling expansion valve (25c) is adjusted to a predetermined opening degree. The opening degree of the pressure control valve (45) is set to a fully closed state, and the flow path opening / closing valve (46) is set to a closed state. The compressor (21), the outdoor fan (22a), and the indoor fan (27a) are set to the driving state, and the circulation pump (33) is set to the driving state.

The refrigerant discharged from the compressor (21) flows into the outdoor heat exchanger (22), dissipates heat to the outdoor air and condenses in the outdoor heat exchanger (22). The refrigerant flowing out of the outdoor heat exchanger (22) sequentially passes through the fully opened outdoor expansion valve (23) and the outdoor subcooling heat exchanger (24) and flows into the liquid refrigerant flow path (12). The refrigerant flowing into the liquid refrigerant channel (12) passes through the first connection point (P1) and flows into the bypass channel (14). The refrigerant flowing into the bypass channel (14) flows into the refrigerant side passage (41a) of the preheating heat exchanger (41) and passes through the refrigerant side passage (41a) of the preheating heat exchanger (41). The heat is transferred to the heat storage medium flowing through the heat storage side passage (41b) and cooled. The refrigerant flowing out of the refrigerant side passage (41a) of the preheating heat exchanger (41) passes through the fully open heat storage expansion valve (42) and the open second open / close valve (52) to exchange heat for heat storage. Into the refrigerant side passage (43a) of the heat exchanger (43) and dissipate heat to the heat storage medium flowing through the heat storage side passage (43b) while passing through the refrigerant side passage (43a) of the heat storage heat exchanger (43) and cool it Is done. The refrigerant that has flowed out of the refrigerant side passage (43a) of the heat storage heat exchanger (43) passes through the third open / close valve (53) and the third check valve (51c) in the open state in order, and the liquid refrigerant flow path. (12), and sequentially passes through the third connection point (P3) and the second connection point (P2) in the liquid refrigerant flow path (12) and flows into the heat storage side subcooling heat exchanger (25), It cools in the heat storage side subcooling heat exchanger (25). The refrigerant cooled in the heat storage side supercooling heat exchanger (25) is decompressed in the indoor expansion valve (26) and flows into the indoor heat exchanger (27), and absorbs heat from indoor air in the indoor heat exchanger (27). Then evaporate. Thereby, indoor air is cooled. The refrigerant that has flowed out of the indoor heat exchanger (27) passes through the gas refrigerant channel (13), is sucked into the compressor (21), and is compressed again.

In the heat storage circuit (31), the heat storage medium flowing out of the heat storage tank (32) flows into the heat storage side passage (41b) of the preheating heat exchanger (41), and the heat storage side passage of the preheating heat exchanger (41). Heat is absorbed from the refrigerant flowing through the refrigerant side passage (41a) while passing through (41b). The heat storage medium flowing out from the heat storage side passage (41b) of the preheating heat exchanger (41) passes through the circulation pump (33) and flows into the heat storage side passage (43b) of the heat storage heat exchanger (43), Heat is absorbed from the refrigerant flowing through the refrigerant side passage (43a) while passing through the heat storage side passage (43b) of the heat storage heat exchanger (43). The heat storage medium that has flowed out of the heat storage side passage (43b) of the heat storage heat exchanger (43) flows into the heat storage tank (32). In this way, cold heat is applied from the heat storage medium to the refrigerant.

(Cooling / cooling operation)
Next, the cooling and accumulating operation will be described with reference to FIG. The cooling / storage operation is an operation in which the remaining cold energy is stored in the heat storage tank while the room is cooled using a part of the cold energy obtained by the refrigeration cycle of the refrigerant circuit (11). That is, cold storage and cooling are performed simultaneously in the cooling storage operation.

In the refrigerant circuit (11), the outdoor heat exchanger (22) is a condenser and the preheating heat exchanger (41) is a subcooler, and the indoor heat exchanger (27) and the heat storage heat exchanger (43) are evaporators. The refrigeration cycle (cooling storage cycle) is performed. On the other hand, the circulation operation is performed in the heat storage circuit (31).

Specifically, the four-way selector valve (28) is set to the first state. Thereby, as for the compressor (21), the discharge end is connected to the gas end of an outdoor heat exchanger (22), and the suction | inhalation end is connected to a gas refrigerant flow path (13). Further, the first on-off valve (51) is set in the open state, and the second on-off valve (52) and the third on-off valve (53) are set in the closed state. The opening degree of the outdoor expansion valve (23) is set to a fully open state, and the opening degree of the indoor expansion valve (26) is a predetermined opening degree (an opening degree at which the superheat degree of the refrigerant at the outlet of the indoor heat exchanger becomes the target superheat degree. ) And the opening degree of the heat storage expansion valve (42) is adjusted to a predetermined opening degree (an opening degree at which the superheat degree of the refrigerant at the outlet of the heat storage heat exchanger (43) becomes the target superheat degree). The opening degree of the outdoor supercooling expansion valve (24c) is set to a fully closed state, and the opening degree of the heat storage side supercooling expansion valve (25c) is adjusted to a predetermined opening degree. The opening degree of the pressure control valve (45) is adjusted to a predetermined opening degree, and the flow path opening / closing valve (46) is set to a closed state. The compressor (21), the outdoor fan (22a), and the indoor fan (27a) are set to the driving state, and the circulation pump (33) is set to the driving state.

The refrigerant discharged from the compressor (21) flows into the outdoor heat exchanger (22), dissipates heat to the outdoor air and condenses in the outdoor heat exchanger (22). The refrigerant flowing out of the outdoor heat exchanger (22) sequentially passes through the fully opened outdoor expansion valve (23) and the outdoor subcooling heat exchanger (24) and flows into the liquid refrigerant flow path (12). A part of the refrigerant that has flowed into the liquid refrigerant flow path (12) and passed through the first connection point (P1) flows into the first on-off valve (51) that is open, and the remainder is the bypass flow path (14 ). The refrigerant that has passed through the opened first on-off valve (51) flows into the heat storage side subcooling heat exchanger (25) and is cooled in the heat storage side subcooling heat exchanger (25). The refrigerant cooled in the heat storage side supercooling heat exchanger (25) is decompressed in the indoor expansion valve (26) and flows into the indoor heat exchanger (27), and absorbs heat from indoor air in the indoor heat exchanger (27). Then evaporate. Thereby, indoor air is cooled. The refrigerant that has flowed out of the indoor heat exchanger (27) flows into the gas refrigerant channel (13). On the other hand, the refrigerant flowing into the bypass channel (14) flows into the refrigerant side passage (41a) of the preheating heat exchanger (41) and passes through the refrigerant side passage (41a) of the preheating heat exchanger (41). During this time, heat is radiated to the heat storage medium flowing through the heat storage side passage (41b) and cooled. The refrigerant flowing out from the refrigerant side passage (41a) of the preheating heat exchanger (41) is decompressed in the heat storage expansion valve (42) and flows into the refrigerant side passage (43a) of the heat storage heat exchanger (43). Then, while passing through the refrigerant side passage (43a) of the heat storage heat exchanger (43), it absorbs heat from the heat storage medium flowing through the heat storage side passage (43b) and evaporates. The refrigerant that has flowed out of the refrigerant side passage (43a) of the heat storage heat exchanger (43) is depressurized by the pressure adjusting valve (45) of the pressure adjusting mechanism (44) and flows into the gas refrigerant channel (13). In the gas refrigerant flow path (13), the refrigerant that has passed through the indoor heat exchanger (27) and the refrigerant that has passed through the pressure adjustment valve (45) of the pressure adjustment mechanism (44) merge and are sucked into the compressor (21). And compressed again.

Thus, in the preheating heat exchanger (41), the heat storage medium flowing through the heat storage side passage (41b) is heated by the refrigerant flowing through the refrigerant side passage (41a). As a result, the clathrate hydrate contained in the heat storage medium flowing out from the heat storage tank (32) can be melted, so that a large amount of clathrate hydrate is generated in the heat storage circuit (31) and the heat storage medium is circulated. It can suppress that efficiency falls. Specifically, the clathrate hydrate of the heat storage medium in the piping part (including the heat storage side passage (43b) of the heat storage heat exchanger (43)) through which the heat storage medium flowing out from the preheat heat exchanger (41) flows It is possible to prevent the pipes forming the heat storage circuit (31) from being blocked due to a large amount of being generated.

[Control in cooling storage operation]
Next, control (control by the controller (100)) in the cooling and regenerating operation shown in FIG. 6 will be described. In the cooling and regenerative operation, the controller (100) performs the indoor side superheat degree control, the heat storage side superheat degree control, the target low pressure control, and the heat storage side evaporation temperature control in parallel. Note that the temperature and the degree of superheat described below can be detected based on detection values of various sensors (not shown).

<Indoor superheat control>
In the indoor side superheat degree control, the controller (100) sets the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (27) (hereinafter referred to as the indoor side refrigerant superheat degree) to a preset indoor side target superheat degree. Thus, the opening degree of the indoor expansion valve (26) is adjusted. Specifically, when the indoor-side refrigerant superheat degree becomes larger than the indoor-side target superheat degree, the controller (100) increases the opening degree of the indoor expansion valve (26), and the indoor-side refrigerant superheat degree becomes the indoor-side target superheat degree. When it is smaller than the degree, the opening degree of the indoor expansion valve (26) is decreased. The controller (100) decreases the indoor-side target superheat degree as the difference between the room air temperature and the preset target cooling temperature (the difference value obtained by subtracting the room air temperature from the target cooling temperature) increases. Set the indoor-side target superheat degree.

<Heat storage side superheat control>
In the heat storage side superheat degree control, the controller (100) is configured such that the superheat degree of the refrigerant at the outlet of the heat storage heat exchanger (43) (hereinafter referred to as heat storage side refrigerant superheat degree) is set in advance. Thus, the opening degree of the heat storage expansion valve (42) is adjusted. Specifically, when the heat storage side refrigerant superheat degree becomes larger than the heat storage side target superheat degree, the controller (100) increases the opening of the indoor expansion valve (26), and the heat storage side refrigerant superheat degree becomes the heat storage side target superheat. When it is smaller than the degree, the opening degree of the indoor expansion valve (26) is decreased. The heat storage side refrigerant superheat degree can be calculated based on detection values of the first refrigerant temperature sensor (61) and the second refrigerant temperature sensor (62).

<Target low pressure control>
In the target low pressure control, the controller (100) controls the compressor (100) so that the low pressure in the refrigerant circuit (11) (in this example, the suction pressure of the compressor (21)) becomes a preset target low pressure. 21) Control the rotation speed. Specifically, the controller (100) increases the rotation speed of the compressor (21) when the suction pressure of the compressor (21) becomes higher than the target low pressure, and the suction pressure of the compressor (21) becomes the target. When the pressure is lower than the low pressure, the rotational speed of the compressor (21) is decreased. The controller (100) sets the target low pressure so that the target low pressure decreases as the cooling load (that is, the difference between the room air temperature and the target refrigerant temperature) increases.

<Heat storage side evaporation temperature control>
In the heat storage side evaporation temperature control, the controller (100) prevents the refrigerant evaporation temperature (hereinafter referred to as heat storage side evaporation temperature) in the heat storage heat exchanger (43) from falling below a preset lower limit evaporation temperature. The amount of pressure reduction in the pressure adjusting mechanism (44) is adjusted. The lower limit evaporating temperature is set to the lower limit temperature of the refrigerant evaporating temperature suitable for cooling the heat storage medium in the heat storage heat exchanger (43) (hereinafter referred to as an appropriate evaporating temperature range). The appropriate range of the evaporation temperature can be set based on the hydrate formation temperature of the heat storage medium and the size (heat exchange area) of the heat storage heat exchanger (43). For example, when an aqueous solution of tetra-n-butylammonium bromide is used as a heat storage medium, the appropriate range of the evaporation temperature is set to a range of about 4 ° C. to 7 ° C., and the lower limit evaporation temperature is set to 4 ° C.

In this example, the controller (100) adjusts the opening degree of the pressure control valve (45) of the pressure adjustment mechanism (44) so that the heat storage side evaporation temperature becomes a preset reference evaporation temperature. Specifically, the controller (100) decreases the opening of the pressure control valve (45) when the heat storage side evaporation temperature becomes lower than the reference evaporation temperature, and when the heat storage side evaporation temperature becomes higher than the reference evaporation temperature, Increase the opening of the pressure control valve (45). The reference evaporation temperature is set to a temperature obtained by adding a predetermined temperature (for example, 1 ° C.) to the lower limit evaporation temperature (that is, a temperature higher than the lower limit evaporation temperature). However, the reference evaporation temperature is preferably set to a temperature that is the same as or lower than the upper limit temperature of the appropriate range of the evaporation temperature.

In this example, the controller (100) regards the detected value of the second refrigerant temperature sensor (62) (that is, the refrigerant inlet temperature of the heat storage heat exchanger (43)) as the heat storage side evaporation temperature, and stores the heat on the heat storage side. It is configured to perform temperature control.

<Specific examples of control by controller>
When the cooling load increases (that is, the indoor air temperature becomes higher than the target cooling temperature), the target low pressure is decreased. As a result, the suction pressure of the compressor (21) becomes higher than the target low pressure, the number of rotations of the compressor (21) increases and the suction pressure of the compressor (21) decreases, and as a result, indoor heat exchange The refrigerant evaporating pressure in the condenser (27) decreases, and the refrigerant evaporating temperature in the indoor heat exchanger (27) decreases. In this way, the cooling capacity (that is, the cooling capacity) in the indoor heat exchanger (27) is ensured.

On the other hand, as the suction pressure of the compressor (21) decreases, the evaporation pressure of the refrigerant in the heat storage heat exchanger (43) also decreases. Thereby, the evaporation temperature of the refrigerant in the heat storage heat exchanger (43) is lowered, and the detection value of the second refrigerant temperature sensor (62) (that is, the refrigerant inlet temperature of the heat storage heat exchanger (43)) is also lowered. . When the refrigerant outlet temperature of the heat storage heat exchanger (43) becomes lower than the reference evaporation temperature, the opening degree of the pressure adjustment valve (45) of the pressure adjustment mechanism (44) decreases. Thereby, the pressure reduction amount of the refrigerant in the pressure control valve (45) is increased, and the evaporation pressure of the refrigerant in the heat storage heat exchanger (43) is increased. As a result, the refrigerant is evaporated in the heat storage heat exchanger (43). The temperature rises.

[Effects of the embodiment]
As described above, by providing the pressure adjustment mechanism (44), the cooling pressure storage operation (that is, when the cooling storage cycle is performed in the refrigerant circuit (11)) becomes higher than the suction pressure of the compressor (21). Thus, the evaporation pressure of the refrigerant in the heat storage heat exchanger (43) can be adjusted. Thereby, the fall of the evaporating pressure of the refrigerant | coolant in the heat storage heat exchanger (43) accompanying the fall of the suction pressure of a compressor (21) can be suppressed, and the evaporating temperature of the refrigerant | coolant in the heat storage heat exchanger (43) Can be prevented from becoming too low. Therefore, it is possible to prevent the heat storage medium from being excessively cooled in the heat storage heat exchanger (43), and it is possible to suppress a decrease in circulation efficiency of the heat storage medium in the heat storage circuit (31). In this example, the heat storage medium is excessively cooled in the heat storage heat exchanger (43), and a large amount of clathrate hydrate (that is, a solid component) is generated, thereby reducing the circulation efficiency of the heat storage medium (specifically (Clogging of the piping of the heat storage circuit (31) by the clathrate hydrate). Thus, since it is possible to prevent the heat storage medium from being excessively cooled in the heat storage heat exchanger (43), the cooling capacity (that is, the cooling capacity) in the indoor heat exchanger is ensured in the cooling and storing operation. The reduction in the circulation efficiency of the heat storage medium in the heat storage circuit (31) can be suppressed.

Also, the amount of pressure reduction in the pressure adjustment mechanism (44) (specifically, the opening of the pressure adjustment valve (45)) is set so that the evaporation temperature of the refrigerant in the heat storage heat exchanger (43) does not fall below the lower limit evaporation temperature. By adjusting, the evaporating pressure of the refrigerant in the heat storage heat exchanger (43) can be set appropriately. Thereby, since the heat storage medium can be appropriately cooled in the heat storage heat exchanger (43), cold storage can be appropriately performed in the cooling and cold storage operation.

By configuring the pressure control mechanism (44) using the pressure control valve (45), the amount of pressure reduction in the pressure control mechanism (44) can be adjusted by adjusting the opening of the pressure control valve (45). Thereby, the evaporation pressure of the refrigerant in the heat storage heat exchanger (43) can be adjusted to be higher than the suction pressure of the compressor (21), and the heat storage medium is cooled in the heat storage heat exchanger (43). It is possible to prevent being overdone.

By constructing the pressure control mechanism (44) using the pressure control valve (45) and the flow path on / off valve (46), the flow path on / off valve (46) is set to the open state and the pressure control valve (45) Can be set to a fully closed state. Thereby, a refrigerant | coolant can be distribute | circulated between the heat exchanger for heat storage (43) and a gas refrigerant flow path (13) via a flow-path on-off valve (46). In addition, the pressure loss in the flow path opening / closing valve (46) is smaller than the pressure loss in the pressure control valve (45). Therefore, the pressure loss in the pressure control mechanism (44) is less than when the refrigerant is circulated between the heat storage heat exchanger (43) and the gas refrigerant flow path (13) via the pressure control valve (45). Can be reduced. Thereby, in another operation different from the cooling and regenerating operation, the pressure loss in the pressure adjusting mechanism (44) can be reduced, and the other operation can be appropriately performed.

(Other embodiments)
The heat storage medium may be a heat storage material other than an aqueous solution of tetra nbutylammonium bromide containing tetra nbutylammonium bromide. The concentration of the heat storage medium may not be limited to 40%.

Further, the above embodiments may be combined as appropriate. The above embodiments are essentially preferred examples, and are not intended to limit the scope of this disclosure, its application, or its application.

As described above, the above-described heat storage type air conditioner is useful as an air conditioner capable of storing cold using the heat storage action of the heat storage medium.

DESCRIPTION OF SYMBOLS 10 Thermal storage type air conditioner 11 Refrigerant circuit 12 Liquid refrigerant flow path 13 Gas refrigerant flow path 14 Bypass flow path 14d 1st branch piping (1st flow path part)
14e Second branch pipe (second flow path)
15 branch channel 20a outdoor unit 20b indoor unit 21 compressor 22 outdoor heat exchanger 22a outdoor fan 23 outdoor expansion valve 24 outdoor subcooling heat exchanger 25 heat storage side subcooling heat exchanger 26 indoor expansion valve 27 indoor heat exchanger 27a Indoor fan 28 Four-way switching valve 30 Thermal storage unit 31 Thermal storage circuit 32 Thermal storage tank 33 Circulation pump 41 Preheating heat exchanger 42 Thermal storage side expansion valve 43 Thermal storage heat exchanger 44 Pressure regulation mechanism 45 Pressure regulation valve 46 Channel opening / closing valve ( On-off valve)
51 First Open / Close Valve 52 Second Open / Close Valve 53 Third Open / Close Valve 61 First Refrigerant Temperature Sensor 62 Second Refrigerant Temperature Sensor 100 Controller (Operation Control Unit)

Claims

Compressor (21), outdoor heat exchanger (22), indoor heat exchanger (27), liquid end of the outdoor heat exchanger (22) and liquid end of the indoor heat exchanger (27) are connected The liquid refrigerant flow path (12), the gas refrigerant flow path (13) to which the gas end of the indoor heat exchanger (27) is connected, and the other end connected to the liquid refrigerant flow path (12). A refrigerant circuit (11) having a bypass channel (14) connected to the gas refrigerant channel (13),
A heat storage circuit (31) through which a heat storage medium in which a solid component is generated by cooling flows;
A heat storage heat exchanger connected to the bypass flow path (14) and the heat storage circuit (31) and exchanging heat between the refrigerant flowing through the bypass flow path (14) and the heat storage medium flowing through the heat storage circuit (31). (43)
A pressure adjusting mechanism (44) provided between the heat storage heat exchanger (43) and the gas refrigerant channel (13) in the bypass channel (14);
In the refrigerant circuit (11), the discharge end of the compressor (21) is connected to the gas end of the outdoor heat exchanger (22), and the suction end of the compressor (21) is connected to the gas refrigerant flow path (13 ), And the outdoor heat exchanger (22) serves as a condenser, and the indoor heat exchanger (27) and the heat storage heat exchanger (43) serve as an evaporator.
The pressure adjustment mechanism (44) is configured to be capable of adjusting the pressure of the refrigerant flowing between the heat storage heat exchanger (43) and the gas refrigerant flow path (13). Air conditioner.
In claim 1,
The pressure control is performed so that the refrigerant circuit (11) is controlled so that the cooling and regenerating cycle is performed, and the evaporation temperature of the refrigerant in the heat storage heat exchanger (43) does not fall below a preset lower limit evaporation temperature. The regenerative air conditioner further comprising an operation control unit (100) for adjusting the amount of pressure reduction in the mechanism (44).
In claim 1 or 2,
The bypass channel (14) has a first channel part (14d) connecting the heat storage heat exchanger (43) and the gas refrigerant channel (13),
The pressure regulation mechanism (44) is configured to be adjustable in opening degree, and has a pressure regulation valve (45) provided in the first flow path portion (14d), and is a heat storage type. Air conditioner.
In claim 3,
The bypass flow path (14) is provided in parallel with the first flow path portion (14d) to connect the heat storage heat exchanger (43) and the gas refrigerant flow path (13). Part (14e)
The pressure adjusting mechanism (44) is configured to be able to switch between opening and closing thereof, and further includes an on-off valve (46) provided in the second flow path portion (14e). Harmony machine.