JP3082752B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system,
In particular, the present invention relates to a technique for adjusting a refrigerant amount in a so-called multi-system refrigeration apparatus.

[0002]

2. Description of the Related Art A so-called multi-system refrigeration apparatus in which a plurality of outdoor units each having a compressor are connected in parallel has been known.

Referring to FIG. 4, a conventional refrigeration system (20
The configuration of (0) will be described. This refrigeration apparatus (200) includes a first outdoor unit (201), a second outdoor unit (202), and a plurality of indoor units (203), (203),.

The first outdoor unit (201) includes a first sub-receiver (208), a first compressor (204), and a first four-way switching valve (20).
5), a first heat source side heat exchanger (206), and a first expansion valve (207). The discharge side pipe of the first compressor (204) and the suction side pipe of the first sub-receiver (208) are connected by a pressure equalizing pipe (215) provided with a first solenoid valve (214). The second outdoor unit (202) includes a second sub-receiver (209), a second compressor (210), a second four-way switching valve (211), and a second heat source side heat exchanger.
(212) and a second expansion valve (213). 2nd compressor
The discharge side pipe of (210) and the suction side pipe of the second sub-receiver (209) are connected by a pressure equalizing pipe (217) provided with a second solenoid valve (216). Each indoor unit (203) is provided with a use-side heat exchanger (218) and a flow control valve (219).

[0005] A main receiver (220) is connected to the first expansion valve (207) and the second expansion valve (213). The main receiver (220) is also connected to a flow control valve (219) of each indoor unit (203). A distributor (221) is connected to the first four-way switching valve (205) and the second four-way switching valve (211), and the other end of the distributor (221) is connected to each use-side heat exchanger (218). It is connected to the.

[0006] A first high-pressure shut-off valve (223) is provided in a connection pipe (222) connecting the second four-way switching valve (211) and the distributor (221). Between a pipe between the first four-way switching valve (205) and the first heat source side heat exchanger (206) and a pipe between the second four-way switching valve (211) and the second heat source side heat exchanger (212); The piping of the bypass pipe (224)
Connected by In this bypass pipe (224),
A second high pressure shutoff valve (225) is provided.

The present refrigeration system (200) is operated in accordance with a refrigeration load.
The operation of the second outdoor unit (202) may be stopped while the operation of the first outdoor unit (201) is being performed. That is, the first
There is an operation mode in which the compressor (204) is operated and the operation of the second compressor (210) is stopped.

In this operation mode, in the cooling operation, the first four-way switching valve (205) and the second four-way switching valve (211) are both set to the solid line side in the drawing, and the first high-pressure cutoff valve (223) is set. Is opened, and the second high-pressure cutoff valve (225), the second expansion valve (213), and the second solenoid valve (216) are closed. Thereby, the high pressure side is shut off on the second outdoor unit (202) side, and the refrigerant inside the unit (202) is discharged through the connection pipe (222). Therefore, the inside of the second outdoor unit (202) is in an empty state where almost no refrigerant remains.

On the other hand, in the heating operation, the first four-way switching valve (20
5) and the second four-way switching valve (211) are both set on the broken line side in the drawing, the second high-pressure shutoff valve (225) is opened, and the first high-pressure shutoff valve (223) and the second expansion valve (213) are opened. And the second solenoid valve (216) is closed. As a result, the high pressure side of the second outdoor unit (202) is shut off, the refrigerant inside the second outdoor unit (202) is discharged through the bypass pipe (224), and the inside becomes empty with almost no refrigerant remaining.

Thus, in the conventional refrigeration system (200),
When there is a unit to stop the operation, the refrigerant inside the unit is discharged and the inside of the unit is emptied to adjust the refrigerant amount of the refrigerant circuit.

[0011]

However, the conventional refrigeration system (200) requires a relatively large-capacity receiver (220) to store the refrigerant recovered from the unit that has stopped operating. Also, dedicated shut-off valves (223) and (225) were required to shut off the high pressure side of the unit whose operation was stopped.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and an object of the present invention is to reduce or reduce the size of a receiver for adjusting the amount of refrigerant in a multi-system refrigeration apparatus. .

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention does not regulate the amount of refrigerant by discharging the refrigerant from the drive unit during operation stop, but instead adjusts the drive unit during operation stop. The amount of the refrigerant is adjusted by storing a predetermined amount of the refrigerant.

Specifically, the first invention provides a driving unit (1) having driving means (18, 27, D) for generating a circulating driving force of the refrigerant.
(4, 15), and a utilization unit that allows the refrigerant to exchange heat and recover heat
(16) and a refrigerant circuit (10) connected via a pipe, wherein the drive unit is a first drive unit (14).
And a second operation that can be stopped freely in a predetermined operation mode.
A refrigerant amount adjusting means for storing at least a predetermined amount of refrigerant in the second driving portion (15) and adjusting the amount of refrigerant circulated in the refrigerant circuit (10) in the operation mode.
(C).

According to the above description, in the predetermined operation mode, the driving force generated by the first driving unit (14) is used by the utilization unit.
In (16), a refrigerant circulation operation for performing heat recovery is performed. At this time, a predetermined amount of refrigerant is stored in the second drive unit (15) whose operation has been stopped. Therefore, the second driving unit
Since the excess refrigerant to be stored in portions other than (15) is reduced or reduced, the size of the receiver provided in the refrigerant circuit (10) can be reduced or reduced. In addition, the second drive unit (15)
Since there is no need to forcibly discharge the refrigerant inside, an on-off valve for shutting off the high pressure side is not required, and the configuration of the refrigerant circuit (10) is simplified.

According to a second aspect, in the first aspect,
The first drive unit (14) includes a first compressor (18), a first four-way switching valve (1).
9), a first heat source side heat exchanger (20), and a first expansion mechanism (21), which are sequentially connected to the liquid line and the gas line, and the second drive unit (15) includes a second compressor (15). 27), a second four-way switching valve (28), a second heat source side heat exchanger (29), and a second expansion mechanism (30), which are connected to the liquid line and the gas line, and 1
6) includes a use side heat exchanger (35) connected to the liquid line and the gas line, and the refrigerant amount adjusting means (C) includes a main receiver (37) provided in the liquid line; Second bypass passage connecting the discharge side and the suction side of the second compressor (27)
(34) and a second bypass valve (33) provided in the second bypass passage (34).

As described above, in the first drive section (14), the first compressor (18) generates a circulating drive force for the refrigerant. In the second drive section (15), the second compressor (27) generates a circulating drive force for the refrigerant.

In the predetermined operation mode for recovering cold heat in the utilization section (16), the refrigerant discharged from the first compressor (18) of the first drive section (14) passes through the first four-way switching valve (19). Pass, condensed in the first heat source side heat exchanger (20), expanded in the first expansion mechanism (21), passed through the main receiver (37), and used in the use side heat exchanger (35)
The refrigerant is evaporated to recover the cold heat, and is sucked into the first compressor (18) via the first four-way switching valve (19). In the second drive unit (15), after the refrigerant flows from the main receiver (37) and passes through the second heat source side heat exchanger (29) and the second four-way switching valve (28), the refrigerant flows into the second Pass through the bypass pipe (34). As described above, the refrigerant flows into the second drive unit (15), and the refrigerant accumulates in the second drive unit (15).

On the other hand, in the predetermined operation mode in which the heat is recovered in the utilization section (16), the first compressor (18) of the first drive section (14) is used.
The refrigerant discharged from is passed through the first four-way switching valve (19),
The heat is condensed in the use-side heat exchanger (35), and the heat is recovered. After that, it is sucked into the first compressor (18). The refrigerant flowing into the second drive section (15) passes through the second bypass pipe (34) and flows into the second heat source side heat exchanger (29).
As described above, the refrigerant flows into the second drive unit (15), and the refrigerant accumulates in the second drive unit (15).

According to a third aspect, in the first aspect,
The first and second drive units (14, 15) each include a first storage unit (141) and a second storage unit (142) for storing a refrigerant, and a pressurization unit for heating the refrigerant to generate a high pressure. (131), a pressure reducing means (150) for cooling the refrigerant to generate a low pressure,
Communication means (M) for communicating one of the storage means (141) and the second storage means (142) with the pressurizing means (131) and communicating the other storage means with the pressure reducing means (150). ), And the utilization unit (16) is provided with each of the storage means (141, 14).
2) a user-side heat exchanger (35) communicating with the
The refrigerant extruded from the storage means connected to (131) is heat-exchanged in the use side heat exchanger (35), and is recovered to the storage means connected to the decompression means (150), and the refrigerant amount is adjusted. The means (C) includes: a first communication path (50a, 53) for communicating the first storage means (141) of the second drive unit (15) with the low-pressure side pipe;
A second communication path (50b, 53) for communicating the second storage means (142) of the drive section (15) with the low-pressure pipe, and a first opening / closing valve provided in the first communication path (50a, 53) (51) and a second on-off valve (52) provided in the second communication path (50b, 53).

According to the above, one storage means is pressurized and the other storage means is depressurized by the communication means (M). As a result, the refrigerant flows out of the pressurized storage unit, and the refrigerant flows through the utilization unit (16) to perform heat recovery, and is then recovered by the depressurized storage unit. In this way, a circulating drive force of the refrigerant is generated in each of the driving units (14) and (15).

In an operation mode in which the operation of the first drive unit (14) is performed while the operation of the second drive unit (15) is stopped, the first on-off valve (51) and the second on-off valve (52) are opened. And the second drive unit (1
The first and second storage means (141) and (142) of (5) are a refrigerant circuit (10).
And the pressure is reduced. As a result, the refrigerant flows into both storage means (141) and (142) of the second drive section (15), and the refrigerant is stored in the second drive section (15).

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> As shown in FIG.
The refrigeration apparatus according to the embodiment includes a first drive unit (14) housed in a first outdoor unit (11), a second drive unit (15) housed in a second outdoor unit (12), and a plurality of units. (3 in FIG. 1, but may be two or four or more). A refrigerant circuit (10) is formed by connecting via a pipe to a utilization part (16) housed in an indoor unit (13). ).

The first driving section (14) includes a first sub-receiver (1)
7), the first compressor (18), the capacity of which is freely controlled,
A four-way switching valve (19), a first heat source side heat exchanger (20), and a first expansion valve (21) are sequentially provided. The discharge pipe of the first compressor (18) and the inflow pipe of the first sub-receiver (17) are connected by a first pressure equalizing pipe (23) provided with a first solenoid valve (22). The discharge side pipe and the suction side pipe of the first compressor (18)
They are connected by a first bypass pipe (25) provided with a first bypass valve (24).

The structure of the second drive section (15) is the same as that of the first drive section (14).
It is almost the same as That is, the second drive section (15)
A sub-receiver (26), a constant capacity second compressor (27), a second four-way switching valve (28), a second heat source side heat exchanger (29), and a second expansion valve (30) are sequentially provided. I have. A discharge side pipe of the second compressor (27) and an inflow side pipe of the second sub-receiver (26) are provided with a second solenoid valve.
(31) are connected by a second pressure equalizing pipe (32) provided. The discharge side pipe and the suction side pipe of the second compressor (27) are connected by a second bypass pipe (34) provided with a second bypass valve (33).

Each utilization section (16) includes a utilization-side heat exchanger (35) and a flow control valve (36).

The first expansion valve (21) and the second expansion valve (30) include:
The main receiver (37) is connected. In addition, the main receiver (37) is also connected to a flow control valve (36) of each utilization section (16). That is, the main receiver (37) is provided between the first expansion valve (21) and the second expansion valve (30), and the flow control valve (36). First four-way switching valve (19) and second four-way switching valve
A distributor (38) is provided between (28) and the use side heat exchanger (35).

The main receiver (37) and the first bypass pipe (2
5), the first bypass valve (24), the second bypass pipe (34) and the second
The bypass valve (33) constitutes a refrigerant amount adjusting means (C).

The present refrigeration system includes both the first drive unit (14) and the second drive unit (15), ie, the first outdoor unit (11) and the second drive unit (11).
A first operation mode for simultaneously operating the outdoor unit (12);
The second driving mode in which only the first driving unit (14) is operated and the operation of the second driving unit (15) is stopped can be selectively executed.

First Operation Mode First, the refrigerant circulation operation in the first operation mode will be described.

During the cooling operation, the first four-way switching valve (19) and the second four-way switching valve (28) are both set to the solid line side in the drawing.
First solenoid valve (22), first bypass valve (24), second solenoid valve (31)
And the second bypass valve (33) is closed. In this state, the refrigerant discharged from the first compressor (18) condenses in the first heat source side heat exchanger (20), expands in the first expansion valve (21), and flows into the main receiver (37). I do. On the other hand, the refrigerant discharged from the second compressor (27) is condensed in the second heat source side heat exchanger (29), expanded in the second expansion valve (30), and flows into the main receiver (37). The refrigerant flowing out of the main receiver (37) evaporates in each use side heat exchanger (35) to cool the room air. The refrigerant flowing out of each use side heat exchanger (35) is distributed by the distributor (38), and a part of the refrigerant is sucked into the first compressor (18) through the first sub-receiver (17), and the other refrigerant Is sucked into the second compressor (27) via the second sub-receiver (26). As described above, in the cooling operation, (61) shown in FIG. 1 is a liquid line, and (62) is a gas line.

During the heating operation, both the first four-way switching valve (19) and the second four-way switching valve (28) are set on the broken line side in the drawing.
First solenoid valve (22), first bypass valve (24), second solenoid valve (31)
And the second bypass valve (33) is closed. In this state, the refrigerant discharged from the first compressor (18) and the refrigerant discharged from the second compressor (27) are merged in the distributor (38), and then combined in the respective use-side heat exchangers (35). Condensed. Thereby, the outdoor air is heated. The refrigerant flowing out of the use side heat exchanger (35) flows into the main receiver (37). Part of the refrigerant in the main receiver (37) flows out to the first drive unit (14), and the other refrigerant flows out to the second drive unit (15). The refrigerant flowing into the first drive unit (14) is evaporated in the first heat source side heat exchanger (20), and then is sucked into the first compressor (18) via the first sub-receiver (17). on the other hand,
The refrigerant flowing into the second drive unit (15) is supplied to the second heat source side heat exchanger.
After evaporating in (29), it is sucked into the second compressor (27) via the second sub-receiver (26).

-Second Operation Mode- Next, the refrigerant circulation operation in the second operation mode will be described.

During the cooling operation, the first four-way switching valve (19) and the second four-way switching valve (28) are set on the solid line side as shown. First bypass valve (24), first solenoid valve (22), and second solenoid valve (31)
Is closed. The second bypass valve (33) is opened. Note that the second expansion valve (30) is open. Then, while driving the first compressor (18), the operation of the second compressor (27) is stopped.

In this state, the refrigerant discharged from the first compressor (18) is condensed in the first heat source side heat exchanger (20) as shown by a solid line arrow in FIG. It expands at 21) and flows into the main receiver (37). Part of the refrigerant in the main receiver (37) flows into the use side heat exchanger (35), exchanges heat with room air, evaporates, and cools the room air. The refrigerant flowing out of the use side heat exchanger (35) is sucked into the first compressor (18) via the first sub-receiver (17).

At this time, part of the refrigerant in the main receiver (37) flows into the second drive section (15), and the second expansion valve (30)
The refrigerant flows through the heat source side heat exchanger (29), the second four-way switching valve (28), and the second bypass pipe (34), and merges with the refrigerant from the use side heat exchanger (35) in the distributor (38). I do. That is, a predetermined amount of refrigerant accumulates in the second drive unit (15) while circulating.

During the heating operation, the first four-way switching valve (19) and the second four-way switching valve (28) are set on the broken line side in the drawing. First bypass valve (24), first solenoid valve (22), and second solenoid valve (31)
Is closed. Second bypass valve (33) and second expansion valve (30)
Is opened. Then, while driving the first compressor (18), the operation of the second compressor (27) is stopped.

In this state, the refrigerant discharged from the first compressor (18) flows into the use side heat exchanger (35) as shown by the dashed arrow in FIG. 1, and exchanges heat with the indoor air. To condense and heat the room air. The refrigerant flowing out of the use-side heat exchanger (35) flows into the main receiver (37) after passing through the flow control valve (36). The refrigerant in the main receiver (37) evaporates in the first heat source side heat exchanger (20) and passes through the first sub-receiver (17) to the first heat receiver.
It is sucked into the compressor (18).

At this time, a part of the refrigerant flows from the distributor (38) into the second drive section (15). The refrigerant flowing into the second drive unit (15) passes through the second bypass pipe (34), the second four-way switching valve (28), the second heat source side heat exchanger (29), and the second expansion valve (30). After passing through, it flows into the main receiver (37) and merges with the refrigerant from the flow control valve (36). That is, a predetermined amount of refrigerant accumulates in the second drive unit (15) while circulating.

As described above, according to the first embodiment, in the second operation mode, the operation of the second drive unit (15) stopped.
Since a predetermined amount of refrigerant accumulates in the main receiver (37)
The amount of refrigerant to be stored in the tank decreases. Therefore, the capacity of the main receiver (37) can be reduced, and the size of the main receiver (37) can be reduced.

Further, a high-pressure shut-off valve for shutting off the high-pressure side of the second drive section (15) becomes unnecessary, and the refrigerant circuit can be simplified.

<Second Embodiment> In the refrigeration apparatus according to the second embodiment, the first drive section (14) and the second drive section (15) are replaced with a heat transfer device (100) as shown in FIG. It is a thing.

The heat transfer device (100) generates a refrigerant circulation driving force by pressurizing and depressurizing the storage means.
The heat transfer device (100) includes a heat source circuit (102) and a drive circuit (103).

The heat source circuit (102) includes a main circuit (157) and a cooling circuit.
(156), the auxiliary circuit (155), and the first to third bypass circuits (1
54), (153) and (152).

The main circuit (157) includes a compressor (160) and a four-way switching valve.
(159), heat source side heat exchanger (128), pressurized heat exchanger (131), expansion valve (134), main heat exchanger (158), and the four-way switching valve (15
9) are connected in order. Heat source side heat exchanger (1
28) and the pressure heat exchanger (131), between the heat source side heat exchanger (1
A first check valve (161) that allows only the refrigerant flow in the direction from the pressure heat exchanger (131) to the pressurized heat exchanger (131) is provided. Expansion valve
A second check valve (162) that allows only the refrigerant flow in the direction from the expansion valve (134) to the main heat exchanger (158) is provided between the main heat exchanger (158) and the main heat exchanger (158). Have been.

The cooling circuit (156) has an upstream end connected between the pressurized heat exchanger (131) and the expansion valve (134) in the main circuit (157), and a downstream end connected to the four ends in the main circuit (157). It is connected between the path switching valve (159) and the suction side pipe of the compressor (160). The cooling circuit (156) is provided with a capillary tube (151) and a reduced-pressure heat exchanger (150) in order from the upstream end to the downstream end.

The auxiliary circuit (155) has one end connected between the pressurized heat exchanger (131) in the main circuit (157) and the upstream end of the cooling circuit (156), and the other end connected to the cooling circuit (156). Is connected between the reduced-pressure heat exchanger (150) and the downstream end. Auxiliary circuit (15
5), the expansion valve (14
9) and an auxiliary heat exchanger (148) are provided.

One end of the first bypass circuit (154) is a main circuit.
(157) is connected between the second check valve (162) and the main heat exchanger (158), and the other end is connected to the pressurized heat exchanger (131) and the cooling circuit (156) in the main circuit (157). Connected to the upstream end of the The first bypass circuit (154) is provided with a receiver (149A) and a third check valve (163) in order from the one end to the other end. The third check valve (163) is a check valve that allows only the refrigerant flow in the direction from the one end to the other end.

One end of the second bypass circuit (153) is a main circuit.
(157) is connected between the expansion valve (134) and the second check valve (162), and the other end is connected to the heat source side heat exchanger in the main circuit (157).
(128) and the first check valve (161). Second
The bypass circuit (153) is provided with a fourth check valve (164) that allows only the refrigerant flow in the direction from one end to the other end.

One end of the third bypass circuit (152) is a main circuit.
(157) is connected between the main heat exchanger (158) and the four-way switching valve (159), and the other end is a first check valve in the main circuit (157).
(161) and the pressurized heat exchanger (131). The third bypass circuit (152) is provided with a fifth check valve (165) that allows only the refrigerant flow in the direction from the one end to the other end.

The drive circuit (103) includes a first tank (141) corresponding to the first storage means, a second tank (142) corresponding to the second storage means, and an auxiliary tank (143).

The upper end of the first tank (141) and the pressurized heat exchanger (13
The upper end of 1) is connected by a pipe provided with a first pressurizing solenoid valve (111). The upper end of the second tank (142) and the upper end of the pressurized heat exchanger (131) are connected by a pipe provided with a second pressurized solenoid valve (112). Auxiliary tank (14
The upper end of 3) and the upper end of the pressurized heat exchanger (131) are connected by a pipe provided with an auxiliary pressurized solenoid valve (113).

The upper end of the first tank (141) and the vacuum heat exchanger (13
The upper end of 2) is connected by a pipe provided with a first pressure reducing solenoid valve (114). The upper end of the second tank (142) and the upper end of the reduced-pressure heat exchanger (132) are connected by a pipe provided with a second reduced-pressure solenoid valve (115). Auxiliary tank (14
The upper end of 3) and the upper end of the reduced-pressure heat exchanger (132) are connected by a pipe provided with an auxiliary reduced-pressure solenoid valve (116).

Below the first tank (141), the first tank
A first outflow check valve (117) that allows only the refrigerant flow in a direction in which the liquid refrigerant in the (141) is supplied to the utilization unit (16), and a utilization unit (16)
A first inflow check valve (118) that allows only the refrigerant flow in the direction from the first tank (141) to the first tank (141), and a direction in which the refrigerant from the vacuum heat exchanger (132) is collected into the first tank (141). And a first recovery check valve (119) that allows only the refrigerant flow.

Similarly, below the second tank (142), a second outflow check valve that allows only the refrigerant flow in the direction in which the liquid refrigerant in the second tank (142) is supplied to the utilization section (16). (120), a second inflow check valve (121) that allows only a refrigerant flow in a direction of flowing from the utilization part (16) to the second tank (142), and a refrigerant from the decompression heat exchanger (132). A second recovery check valve (122) that allows only the refrigerant flow in the direction of recovery in the second tank (142) is provided.

Below the auxiliary tank (143), an auxiliary tank
A liquid supply check valve (123) that allows only the refrigerant flow in the direction of supplying the liquid refrigerant in the (143) to the pressurized heat exchanger (131), and a liquid supply check valve (123) that supplies the liquid refrigerant to the auxiliary tank (143). A liquid supply check valve (124) that allows only the refrigerant flow is provided. In addition,
The auxiliary tank (143) is positioned higher than the pressurized heat exchanger (131) so that the liquid refrigerant in the auxiliary tank (143) flows naturally to the pressurized heat exchanger (131) by the action of gravity. It is installed in.

The first pressurizing solenoid valve (111) and the second pressurizing solenoid valve (11)
2), the first pressure reducing solenoid valve (114), the second pressure reducing solenoid valve (115), the first
One of the tank (141) and the second tank (142) is communicated with the pressurized heat exchanger (131), and the other tank is communicated with the decompressed heat exchanger (132) to circulate the refrigerant. It constitutes a communication means (M) for generating a force. Also,
The heat source circuit (102), the two tanks (141), (142), and the communication means (M) constitute a driving means (D) for generating a refrigerant circulation driving force.

An auxiliary heat exchanger (148) is provided in a pipe for recovering the refrigerant from the utilization section (16) to the first tank (141) or the second tank (142). In addition, auxiliary heat exchanger (148)
Is a heat exchanger provided mainly for adjusting the heat balance of the refrigerant in the heat source circuit (102). In addition, the auxiliary heat exchanger (148) is connected to the first tank (141) or the second tank (141).
It also serves to cool the refrigerant so that air bubbles are not included in the refrigerant flowing into the tank (142).

At the upper ends of the first tank (141) and the second tank (142), a communication pipe (50) for communicating the tanks (141) and (142) with each other.
Is connected. The first tank (141) side of the middle portion is a first communication portion (50a), and the second tank (142) is closer than the middle portion.
The side is a second communication portion (50b). A refrigerant discharge pipe (53) connected to a pipe below the tanks (141) and (142) is connected to an intermediate portion of the communication pipe (50). A first discharge valve (51) is provided between an intermediate portion of the communication pipe (50) and the first tank (141), and a second discharge valve (51) is provided between the intermediate portion and the second tank (142). A discharge valve (52) is provided. A “first communication path” is formed by the first communication part (50a) and the refrigerant discharge pipe (53). Further, a “second communication path” is formed by the second communication part (50b) and the refrigerant discharge pipe (53). The communication pipe (50), the first discharge valve (51), the second discharge valve (52), and the refrigerant discharge pipe (53) constitute a refrigerant amount adjusting means (C).

The pipes provided below the first tank (141) and the second tank (142) (the pipes provided with the outflow check valves (117) and (120)) are merged with each other to perform four-way switching. The first of the valve (147)
Connected to port. One end of the auxiliary heat exchanger (148) is connected to a third port of the four-way switching valve (147). The fourth port of the four-way switching valve (147) is connected to the distributor (38). The second port of the four-way switching valve (147) is connected to the main receiver (37). The four-way switching valve (14
7) is a first communication state in which the first port communicates with the second port and the third port communicates with the fourth port, and a first communication state in which the first port communicates with the fourth port and the second port communicates with the third port. It is configured to be able to select a second communication state for communication.

First Operation Mode First, a first operation mode in which both the first drive unit (14) and the second drive unit (15) are operated at the same time will be described. In the first operation mode, the first discharge valve (51) and the second discharge valve (52) of the heat transfer device (100) of both the driving units (14) and (15) are closed.

In the cooling operation, the four-way switching valve (159) of the heat source circuit (102) and the four-way switching valve (147) of the drive circuit (103) are used.
Are set on the solid line side in the figure.

In the heat source circuit (102), the refrigerant discharged from the compressor (160) is supplied to the heat source side heat exchanger (128) and the pressurized heat exchanger.
Condensed at (131). At this time, the drive circuit (103) side of the pressurized heat exchanger (131) is heated, and a high pressure is generated. The refrigerant flowing out of the main heat exchanger (158) is diverted, a part of the refrigerant is expanded by the expansion valve (134), and another part flows into the cooling circuit (156) and expands by the capillary tube (151). Other parts are auxiliary circuits (155)
And expanded by the expansion valve (149). The refrigerant expanded and decompressed by the expansion valve (134) evaporates in the main heat exchanger (158). On the other hand, the refrigerant expanded and decompressed in the capillary tube (151) evaporates in the decompression heat exchanger (150), and is decompressed by the decompression heat exchanger (150).
A low pressure is generated on the side of the drive circuit (103). Expansion valve (149)
The refrigerant expanded and decompressed in step evaporates in the auxiliary heat exchanger (148), and cools the refrigerant on the drive circuit (103) side collected in the tanks (141) and (142). Then, the refrigerant flowing out of the main heat exchanger (158), the refrigerant flowing out of the reduced pressure heat exchanger (150), and the refrigerant flowing out of the auxiliary heat exchanger (148) are merged and sucked into the compressor (160). .

In each drive circuit (103) of the first drive section (14) and the second drive section (15), a first state and a second state described below are alternately repeated. Thereby, the refrigerant is supplied from both drive circuits (103) to the utilization section (16), and the utilization-side heat exchanger
After the air is evaporated in (35) to cool the room air and condensed in the main heat exchanger (158), it is circulated to be recovered by both drive circuits (103).

In the first state, the first pressurizing solenoid valve (111) and the second pressure reducing solenoid valve (115) are set to the open state. On the other hand, the first pressure reducing solenoid valve (114) and the second pressurizing solenoid valve (112) are set to the closed state. Thereby, the first tank (141) communicates with the pressurized heat exchanger (131), and the second tank (142)
And the reduced pressure heat exchanger (132). As a result, the first tank (141) is pressurized from above, and the liquid refrigerant in the first tank (141) is pushed downward. The extruded refrigerant is the first
It passes through the outflow check valve (117) and the four-way switching valve (147) and flows into each use side heat exchanger (35). This refrigerant exchanges heat with room air in the use-side heat exchanger (35) to evaporate, thereby cooling the room air. The evaporated refrigerant is used in the heat exchanger (35)
After flowing out, the refrigerant is condensed in the main heat exchanger (158), becomes a liquid refrigerant, passes through the four-way switching valve (147), and flows into the drive circuit (103). The refrigerant flowing into the drive circuit (103) is supplied to the second inflow check valve.
It is collected in the second tank (142) through (121). On this occasion,
Since the pressure of the second tank (142) is reduced by the reduced-pressure heat exchanger (132), the collection of the refrigerant in the second tank (142) is performed smoothly.

As described above, the first state is the first tank (1
In this state, the liquid refrigerant supplied from 41) flows through the utilization section (16) and is collected in the second tank (142).

By the way, if the first state is continued as it is, the liquid refrigerant in the first tank (141) tends to be insufficient, while the liquid refrigerant in the second tank (142) tends to be excessive. Therefore, in such a state, the circulation operation of the refrigerant is switched from the first state to the following second state.

In the second state, the first pressurizing solenoid valve (111) and the second depressurizing solenoid valve (115) are set to the closed state, while the first depressurizing solenoid valve (114) and the second pressurizing solenoid valve (112) is a state where it is set to the open state. As a result, the second tank (142)
And the pressurized heat exchanger (131), and the first tank
(141) communicates with the reduced-pressure heat exchanger (132). As a result, the second tank (142) is pressurized from above, and the first tank (141) is depressurized from above. Thereby, contrary to the first state, the liquid refrigerant is pushed out of the second tank (142), and the refrigerant circulation operation of recovering the liquid refrigerant to the first tank (141) is performed.

When the liquid refrigerant in the second tank (142) becomes short, the drive circuit (103) returns to the first state from the second state.
State. As described above, the first state and the second state are alternately repeated, so that the refrigerant continuously circulates.

The auxiliary tank (143) is a storage means for supplying the liquid refrigerant when the liquid refrigerant is insufficient in the pressurized heat exchanger (131), for example, when starting the apparatus. When the liquid refrigerant is insufficient in the pressurized heat exchanger (131), the auxiliary pressurizing solenoid valve (113) is set to the open state and the auxiliary pressure reducing solenoid valve (116) is set to the closed state. As a result, the auxiliary tank (14
3) communicates with the pressurized heat exchanger (131). Therefore, the liquid refrigerant in the auxiliary tank (143) is pushed out, and the liquid supply check valve (123)
To be supplied to the pressurized heat exchanger (131).

On the other hand, when the liquid refrigerant in the auxiliary tank (143) runs short, the auxiliary pressurizing solenoid valve (113) is set to a closed state and the auxiliary pressure reducing solenoid valve (116) is set to an open state. The liquid refrigerant is supplied to the auxiliary tank (143) through the liquid supply check valve (124).

In the heating operation, the four-way switching valve (159) of the heat source circuit (102) and the four-way switching valve (147) of the drive circuit (103) are used.
Are both set on the broken line side in the drawing, and the direction of circulation of the refrigerant in the utilization section (16) is opposite to that during the above-described circulation operation. That is,
The refrigerant supplied from both drive circuits (103) is supplied to the main heat exchanger (15
After being evaporated in 8) and condensed in the use side heat exchanger (35), it is recovered in both drive circuits (103).

-Second Operation Mode- Next, the second drive unit (15) is operated while the first drive unit (14) is operated.
A second operation mode in which the operation of the second operation is stopped will be described. That is, while driving the compressor (160) of the first drive unit (14),
The operation of stopping the compressor (160) of the second drive unit (15) will be described.

In the second operation mode, the first discharge valve (51) and the second discharge valve (52) of the first drive section (14) are both closed, while
The first drive section (14) and the second drive section (15) of the second drive section (15) are both opened.

The refrigerant circulating operation in the utilization section (16) and the refrigerant circulating operation in the first drive section (14) are the same as those in the first operation mode, and therefore the description is omitted. Here, only the refrigerant circulation operation in the second drive unit (15) whose operation is stopped will be described.

In the drive circuit (103) of the second drive section (15), since both the first discharge valve (51) and the second discharge valve (52) are open, both tanks (141), (142) ) Communicates with the low-pressure portion of the refrigerant circuit (10) via the communication pipe (50) and the refrigerant discharge pipe (53). As a result, both tanks (141), (142) of the second drive unit (15)
The pressure inside will drop. And, along with this, the refrigerant circuit (1
0) through the four-way switching valve (147)
The liquid refrigerant flows toward (1) and (142). That is, the tanks (141) and (142) of the second drive unit (15) whose operation has been stopped are:
The refrigerant will accumulate.

As described above, also in the second embodiment,
In the second operation mode, the second drive unit (1
5) A predetermined amount of refrigerant is accumulated in the main receiver (3).
7) The amount of refrigerant to be stored decreases. Therefore, the capacity of the main receiver (37) can be reduced, and the size of the main receiver (37) can be reduced.

In the above embodiment, the first discharge valve (51) and the second discharge valve of the second drive section (15) are in the second operation mode.
(52) is always open, but it is determined whether the refrigerant amount of the refrigerant circuit (10) is appropriate or not, and based on this determination, the discharge valve (5
1) A refrigerant amount adjustment control for performing the opening / closing control of (52) may be performed.

For example, as shown in FIG.
In step 1, it is determined whether or not there is an outdoor unit that is stopped. That is, it is detected whether or not the stopped drive unit exists. As a result, if NO, step ST
In step 6, the operation is determined to be in the first operation mode, and the discharge valves (51) and (52) are set to the OFF state, that is, the closed state.
On the other hand, if the determination result in step ST1 is YES, it is determined that the operation is in the second operation mode, and the process proceeds to step ST2.

Step ST2 is a step of determining a cooling operation or a heating operation. If the determination result is YES, the process proceeds to step ST4, and if the determination result is NO, the process proceeds to step ST3.
Proceed to.

Step ST3 is a step for determining whether or not the refrigerant in the refrigerating apparatus (system) is running short during the heating operation. In the case of YES, the process proceeds to step ST5, and the discharge valves (51) and (52) are set to the ON state, that is, the open state. N
In the case of O, the process proceeds to step ST6.

On the other hand, step ST4 is a step for judging whether or not the refrigerant of the refrigerating apparatus (system) is excessive during the cooling operation. In the case of YES, the process proceeds to step ST5, and in the case of NO, the process proceeds to step ST6.

<Other Embodiments> The term "refrigeration apparatus" as used in the present invention does not mean a refrigeration apparatus in a narrow sense, but is a refrigeration apparatus in a broad sense including an air conditioner and a refrigerator. is there.

[0085]

As described above, according to the present invention, when there is a drive unit that is not in operation, a predetermined amount of refrigerant is stored in the drive unit, so that it is stored in the operating refrigerant circuit. The amount of refrigerant to be used can be reduced. Therefore, the size of the main receiver of the refrigerant circuit can be reduced or reduced.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to a first embodiment.

FIG. 2 is a refrigerant circuit diagram of a drive unit according to a second embodiment.

FIG. 3 is a flowchart of refrigerant amount adjustment control.

FIG. 4 is a refrigerant circuit diagram of a conventional refrigeration apparatus.

[Explanation of symbols]

 (10) Refrigerant circuit (14) First drive unit (15) Second drive unit (16) Utilization unit (18) First compressor (27) Second compressor (35) Utilization side heat exchanger (37) Main Receiver (51) First discharge valve (52) Second discharge valve (102) Heat source circuit (103) Drive circuit (141) First tank (142) Second tank

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 13/00 F25B 29/00 F25B 43/00

Claims (3)

(57) [Claims] 1. A driving means for generating a driving force for circulating a refrigerant.
Refrigerant circuit (10) comprising a drive unit (14, 15) having (18, 27, D) and a utilization unit (16) for performing heat exchange with a refrigerant to perform heat recovery and connected via a pipe. Wherein the drive unit has at least a first drive unit (14) and a second drive unit (15) that can stop operation freely in a predetermined operation mode, A refrigerating apparatus comprising a refrigerant amount adjusting means (C) for storing a predetermined amount of refrigerant in the second drive section (15) in the operation mode to adjust the amount of refrigerant circulated in the refrigerant circuit (10). 2. The refrigeration system according to claim 1, wherein the first drive unit (14) includes a first compressor (18), a first four-way switching valve (1).
9), a first heat source side heat exchanger (20), and a first expansion mechanism (21), which are sequentially connected to the liquid line and the gas line, and the second drive unit (15) is provided with a second compressor ( 27), the second four-way switching valve (2
8), a second heat source side heat exchanger (29), and a second expansion mechanism (30), which are connected to the liquid line and the gas line in order, and the utilization unit (16) is connected to the liquid line and the gas line. And a use-side heat exchanger (35) connected to a main receiver (37) provided in the liquid line and a discharge side of the second compressor (27). A refrigerating apparatus comprising: a second bypass passage (34) that connects the air supply and the suction side; and a second bypass valve (33) provided in the second bypass passage (34). 3. The refrigeration apparatus according to claim 1, wherein the first and second driving units (14, 15) are respectively a first storage unit (141) and a second storage unit (142) for storing a refrigerant. Pressurizing means (131) for heating the refrigerant to generate a high-pressure pressure; depressurizing means (150) for cooling the refrigerant to generate a low-pressure pressure;
Communication means (M) for communicating one of the storage means (141) and the second storage means (142) with the pressurizing means (131) and communicating the other storage means with the pressure reducing means (150). The use unit (16) includes a use-side heat exchanger (35) communicating with the storage means (141, 142), and the refrigerant extruded from the storage means connected to the pressurizing means (131). The use side heat exchanger (3
5) heat is exchanged in the storage means connected to the decompression means (150) and is recovered by the storage means. The refrigerant amount adjusting means (C) is a first storage means of the second drive unit (15).
First communication path (50a, 53) for communicating (141) with the low pressure side pipe
A second communication path (50b, 53) for communicating the second storage means (142) of the second drive section (15) with the low pressure side pipe; and a first communication path (5
0a, 53) and a first on-off valve (51) provided in the second communication passage (5
0b, 53) and a second on-off valve (52).