JP2012189266A - Air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use only one auxiliary heat source unit to handle failures in heat source units of an arbitrary system.SOLUTION: A plurality of systems α, β, γ configured by supplying refrigerant from heat source units 2a, 2b, 2c to heat source circuits α, β, and γ are each provided with a heat source unit 2d. The refrigerant can be supplied from the heat source unit 2d to the heat source circuit γ of the system γ through an outgoing connection pipe 11, a flow rate control valves V2d, and so on. For instance, the heat source unit 2c can supply the refrigerant also to the heat source circuit β through the outgoing connection pipe 13, flow rate control valves V25, V23, and so on.

Description

  The present invention relates to a redundant configuration and redundant operation control of a heat source unit.

  For example, an air conditioning system (air conditioner) that performs management control so that the room temperature of a server room such as a data center is within a predetermined temperature range is known. In general, an air conditioning system is provided with a cooling unit that is supplied with a refrigerant through a pipe and the like, cools the air with the refrigerant, and blows the air into the room with a fan and the like, and supplies the refrigerant to the cooling unit. It consists of a heat source unit. Usually, one heat source unit is provided for a plurality of cooling units. Usually, such a plurality of cooling units are installed at various locations in the server room, for example, and the heat source unit is installed outside the server room (for example, a machine room). The configuration is not limited to such an example, and one heat source unit may be provided for one cooling unit.

  The pipe connected to the heat source unit and each cooling unit includes a pipe for supplying refrigerant from the heat source unit to each cooling unit (referred to as a forward pipe), and returns the refrigerant from each cooling unit to the heat source unit. Piping (refrigerant recovery piping; referred to as return piping).

  The refrigerant supplied from the heat source unit to each cooling unit via the forward pipe rises in temperature by cooling the air in the cooling unit (referred to as a warm refrigerant here), and this hot refrigerant passes through the return pipe. It returns to the heat source unit, is cooled by the heat source unit, becomes a refrigerant, and is supplied again to the cooling unit via the forward pipe.

  Here, naturally, a large number of computer devices (servers, etc.) are installed in the server room such as the data center. In order to prevent the server from going down due to its own heat generation, cooling is performed by the air conditioning system. Is going. Therefore, if there is a failure in the air conditioning system (particularly, a failure in the heat source unit), the risk of the server going down increases, and it is necessary to respond immediately. Therefore, an alternative means provided when the air conditioning system (particularly its heat source unit) breaks down is necessary. For this purpose, for example, it is considered to perform redundant operation with a redundant configuration in which two systems of cooling systems using heat source units are provided.

  Conventionally, in order to perform the above-described redundant operation with a heat source unit that handles refrigerant, for example, two cooling systems each having a heat source unit and a pipe to each cooling unit are used, and the operation is performed using either one of the systems. There are known methods such as switching to the other system when an abnormality occurs. Alternatively, each of the two systems is operated at 50%, and when an abnormality occurs in either of the two systems, the normal system operates at 100% to ensure cooling. However, with this method, particularly when there are a plurality of cooling systems, a large space is required and initial investment at the time of installation is a heavy burden.

Moreover, there exists a prior art of patent document 1. FIG.
The invention of Patent Document 1 relates to a cooling device for a high heating element mounted on an electronic device, and is in a technical field different from an air conditioning system that manages and controls the indoor temperature of a server room or the like. FIG. 4 discloses a dual configuration of the pump.

  For example, as disclosed in paragraph 0048, one of these pumps is for supplying a small capacity refrigerant, and the other is for supplying a large capacity refrigerant. It is also disclosed that the cooling performance is improved by operating both pumps.

JP 2007-294655 A

  In the case of the above-described conventional technology “each of which has two cooling systems each having a heat source unit and a pipe to each cooling unit”, since the two systems are constructed, the scale becomes large and the initial investment at the time of installation becomes a heavy burden. It was. In particular, when there are a plurality of cooling systems, there are two systems for each cooling system, and the scale becomes very large, and the initial investment at the time of installation becomes a very heavy burden.

  In addition, the invention of Patent Document 1 only discloses the duplexing of the pump, and the cooling configuration (the configuration corresponding to the heat source unit such as the heat radiating unit) is not duplexed. Therefore, it cannot cope with a failure of the cooling configuration. Regarding the duplexing of the pump, the invention of the cited document 1 does not have an idea of performing operation using only one of the pumps and switching to the other pump when the pump fails.

  An object of the present invention relates to an air conditioning system including a plurality of heat source circuits having one or more cooling units and configured to supply a refrigerant to the cooling units via a pipe. By providing a heat source unit and a piping configuration that can supply refrigerant from each heat source unit to one or more heat source circuits, even if one of the heat source units fails, supply of refrigerant to all the heat source circuits is maintained without any problem. It is to provide an air conditioning system that can be used.

  The air conditioning system of the present invention includes one or a plurality of cooling units that cool the air-conditioning target space with the supplied refrigerant, a forward pipe for supplying the refrigerant to the one or more cooling units, and the refrigerant from the one or more cooling units. A plurality of heat source circuits each including a return pipe for collecting the heat source circuit, and having a plurality of heat source units for supplying a refrigerant to any of the plurality of heat source circuits, wherein the number of the heat source units is More than the number of the heat source circuits, each of the heat source units is connected to one or a plurality of the heat source circuits via on / off valves, and the heat source units are connected from each heat source unit by opening / closing control of the on / off valves. If a failure occurs in any one or more of the plurality of heat source units and the connecting portion that can supply the refrigerant to one or more of the connected one or more heat source circuits, the failed heat source unit Tsu DOO is a control device that performs the opening / closing control of the valves so as to refrigerant supplied from another heat source unit with respect to the heat source circuit which has been coolant supply.

  In the above air conditioning system, for example, the connecting portion is connected to the forward pipe / return pipe of each of the heat source circuits via the forward pipe / return pipe of one or more other heat source circuits and the opening / closing valve. The control device is configured to supply a refrigerant from another heat source unit to the heat source circuit or to the heat source circuit via the connection portion with respect to the heat source circuit supplied with the refrigerant by the failed heat source unit. The opening / closing control of the on-off valve is performed so that the refrigerant is supplied from the heat source unit that has not been present.

For example, the number of the heat source units is one more than the number of the heat source circuits.
If there is one, there will be a heat source unit (standby unit) that is connected to the heat source circuit but not supplied with refrigerant, but if any heat source unit fails, the failed heat source unit supplies refrigerant. The heat source circuit that has been supplied is supplied with refrigerant from another heat source unit that can supply refrigerant to the heat source unit. In this case, the standby unit does not necessarily supply the refrigerant, and another heat source unit may supply the refrigerant via the connecting portion. When the other heat source unit supplies the refrigerant through the connecting portion, the standby unit may supply the refrigerant to the heat source circuit to which the heat source unit has been supplying the refrigerant. In some cases, the refrigerant is supplied from the heat source unit.

  Here, for example, at least the heat source circuits that are relatively far from each other are not connected by the connecting portion, or the standby unit is not connected to the heat source circuits that are relatively far from each other. As a result, the length of the connecting portion and the distance between the standby unit and the heat source circuit to be connected can be relatively shortened and can be substantially equalized (at least extremely long or large in length). There is no such thing as a variation).

  According to the air conditioning system or the like of the present invention, the number of the plurality of heat source circuits in the air conditioning system provided with a plurality of heat source circuits configured to have one or more cooling units and supply refrigerant to the cooling units via the pipes. By providing a larger number of heat source units and having a piping configuration that allows refrigerant to be supplied from each heat source unit to one or more heat source circuits, even if one of the heat source units fails, all the heat source circuits can be connected without any problem. Refrigerant supply can be maintained. The system configuration can be simplified, and the initial investment at the time of installation can be reduced. Furthermore, the heat source unit can be switched safely and smoothly.

It is a block diagram (the 1) of the air conditioning system of this example. It is a block diagram (the 2) of the air conditioning system of this example. It is a block diagram (the 3) of the air conditioning system of this example. It is a detailed structural example of a forked circuit part.

Embodiments of the present invention will be described below with reference to the drawings.
Here, FIG.1, FIG.2, FIG.3 is a block diagram of the air conditioning system of this example, and all the system configurations are the same. However, FIG. 1, FIG. 2, and FIG. 3 are different from each other with respect to the open / close state of various open / close valves (flow rate adjusting valve V) and the flow of the refrigerant. In FIG. 1, no heat source unit has failed, but in FIG. 2, one heat source unit has failed, and in FIG. 3, two heat source units have failed. In the present description, the flow rate adjusting valves V1a, V2a, V21, V3b, etc. shown in FIG.

  First, with reference to FIG. 1, the structure of the air conditioning system of Example 1 is demonstrated. As described above, the system configuration itself is the same as in FIG. 1 for FIGS. 2 and 3, so this description is also common to FIGS. 2 and 3.

  As described in the prior art, the object to be controlled by the air conditioning system of this example is the room temperature of a server room such as a data center or a computer room. This method is for dealing with a failure of the heat source unit, and is intended to prevent the server or the like from being down due to, for example, heat emitted from a large number of servers installed in the room.

  In addition, although the air-conditioning target space by the air-conditioning system (the cooling unit) of this example is a server room in this description, it is not limited to this example. It may be a clean room. However, this method is used when a large computer such as a server room is installed, and the space itself is a high-temperature heat generation source, and the temperature is likely to rise and the computer is abnormally caused thereby. Has a particularly remarkable effect.

The basic configuration and operation of the air conditioning system of this example shown in FIG. 1 and the like are schematically as follows.
First, the air conditioning system of this example is premised on an air conditioning system in which a plurality of heat source circuits including one or more cooling units 1 and a pipe for supplying a refrigerant to the cooling units are provided. In the example shown in FIG. 1 and the like, an air conditioning system having three heat source circuits of a heat source circuit α, a heat source circuit β, and a heat source circuit γ is shown. Although not particularly illustrated, the cooling unit 1 includes, for example, an evaporator and a fan, and cools air passing through the evaporator by heat of vaporization when the refrigerant evaporates in the evaporator to generate cold air. This is a general well-known configuration.

  The heat source circuit α basically has a plurality of cooling units 1a (however, only one unit may be used. The same applies to other heat source circuits) and for supplying (circulating) the refrigerant to these cooling units 1a. (I.e., the forward pipe 6a and the return pipe 5a). Similarly, the heat source circuit β includes a plurality of cooling units 1b and pipes (outward pipe 6b and return pipe 5b) for supplying refrigerant to these cooling units 1b. The heat source circuit γ includes a plurality of cooling units 1c and pipes (outward pipe 6c and return pipe 5c) for supplying refrigerant to these cooling units 1c.

  The cooling units 1a, 1b, 1c, etc. may be referred to as the cooling unit 1 without particular distinction. Similarly, heat source units 2a, 2b, 2c, 2d, etc., which will be described later, may be referred to as heat source units 2 without being particularly distinguished. Similarly, the forward pipes 6a, 6b, and 6c may be referred to as the forward pipe 6 without being particularly distinguished. Similarly, the return pipes 5a, 5b, 5c may be referred to as the return pipe 5 without being particularly distinguished. In addition, as described in the background art, the forward pipe is a pipe for supplying the refrigerant from the heat source unit to each cooling unit, and the return pipe is a pipe for returning the refrigerant from each cooling unit to the heat source unit. .

  Here, conventionally, the air conditioning system also has a heat source unit 2 for supplying the refrigerant to the heat source circuit (each cooling unit 1 thereof). However, in the air conditioning system of this example, one unit is more than the number of heat source circuits. A large number of heat source units 2 are provided. Accordingly, in the illustrated example, four heat source units 2 (2a, 2b, 2c, 2d) are provided for the three heat source circuits.

  And it is set as the piping structure which can supply a refrigerant | coolant from each heat-source unit 2 to one or more (one or several) heat-source circuit. This is achieved by connecting each heat source unit 2 to the piping of at least one heat source circuit via a valve (flow rate adjusting valve V) and providing a connecting portion that connects the piping of any two heat source circuits. To do. This connecting portion basically includes a pipe and one or more valves (flow rate adjusting valve V), and includes a configuration in which the forward pipes 6 are connected to each other and a configuration in which the return pipes 5 are connected to each other. (Details will be described later).

  For example, when the connecting portion has the configuration shown in FIG. 1, in the illustrated example, first, the heat source unit 2 d can supply the refrigerant to the heat source circuit γ. The heat source unit 2c can supply refrigerant to two heat source circuits, a heat source circuit γ and a heat source circuit β. The heat source unit 2b can supply refrigerant to three heat source circuits, that is, a heat source circuit α, a heat source circuit γ, and a heat source circuit β. The heat source unit 2a can supply refrigerant to two heat source circuits, a heat source circuit α and a heat source circuit γ.

  And the heat source circuit of the refrigerant | coolant supply destination from each heat-source unit 2 can be determined / changed by carrying out open / close control of each valve (flow-rate adjustment valve V). Although this will also be described in detail later, in the state of FIG. 1, the above-mentioned connecting portion is not used (the corresponding flow rate adjustment valve V is closed). Therefore, for example, the heat source unit 2c supplies refrigerant to the heat source circuit γ. The heat source unit 2b supplies the refrigerant to the heat source circuit β, and the heat source unit 2a supplies the refrigerant to the heat source circuit α.

  Here, in the air conditioning system having the above configuration, in the state where there is no failed heat source unit 2, any one heat source unit 2 is left over. That is, there is one heat source unit 2 that does not supply refrigerant to any heat source circuit (heat source unit 2d in the example of FIG. 1). Such a heat source unit 2 is assumed to be in a standby state, and is referred to as “standby heat source unit 2”, “standby unit 2”, “backup heat source unit”, or the like. In the example of FIG. 1, it will be referred to as “standby heat source unit 2d” or “standby unit 2d”.

  Here, in this example, the standby unit 2 is in an operating state by using a self-circulation circuit described later. As a result, when switching from the standby unit 2 to the state in which the refrigerant is supplied to the heat source circuit due to the failure of any heat source unit 2, the refrigerant can be supplied immediately by simply opening and closing the corresponding valves (flow rate adjusting valves V). It becomes like this. That is, the heat source unit can be switched safely and smoothly. When the heat source unit 2 is in a stopped state, it takes a long time to start the heat source unit 2 and make it stable.

  In this example, the number of heat source units 2 is the number of heat source circuits plus one. However, the number is not limited to this example, and the number of heat source units 2 may be larger than the number of heat source circuits. However, when the number of heat source units 2 is one more than the number of heat source circuits (the number of heat source circuits + 1), the most remarkable effect is obtained.

  In the air conditioning system of the configuration example shown in FIG. 1 and the like, basically, the refrigerant can be constantly supplied to all the heat source circuits α, β, γ by two or more heat source units 2 (FIG. 1). The refrigerant can be supplied to all the heat source circuits α, β, γ not only in the state of FIG. This is realized by controlling opening and closing of each valve (flow rate adjusting valve V) according to the situation.

  For example, when the heat source unit 2a fails, the refrigerant can be supplied to all the heat source circuits α, β, γ by setting the open / closed state of each valve (flow rate adjusting valve V) as shown in FIG. . This does not mean that, for example, FIG. 1 is a normal state, FIG. 2 is an abnormal state, and the like. For example, in a state where there is no malfunctioning heat source unit 2, the state shown in FIG. 2 may be used (in this case, the heat source unit 2a becomes the “standby unit 2”).

  Although FIG. 2 will be described in detail later, the heat source units 2b, 2c, and 2d supply refrigerant to the heat source circuits α, β, and γ. For example, the heat source unit 2b supplies refrigerant to the heat source circuit α. Supply.

  Thus, in this method, for example, the heat source units 2a, 2b, and 2c are units used for normal operation, and the heat source unit 2d is not determined to have a redundant configuration (standby unit). Alternatively, for example, the idea is not that the heat source unit 2a is a heat source unit for the heat source circuit α. Basically, “three of the four heat source units 2 supply refrigerant to the three heat source circuits α, β, γ, and the remaining one heat source unit 2 is reserved” However, it is not limited to this example. As described above, the refrigerant may be supplied to all the heat source circuits α, β, γ by the two heat source units 2.

However, for the convenience of explanation, it seems that the explanation is difficult to understand if there is no standard state, so here, the explanation will be made by treating the state shown in FIG. 1 as a default.
For convenience of explanation, a configuration in which refrigerant is supplied from the heat source unit 2 to each heat source circuit α, β, γ for each heat source circuit α, β, γ in such a default state is referred to as a “system”.

  That is, as shown in FIG. 1, for example, a configuration in which refrigerant is supplied from the heat source unit 2a to each cooling unit 1a of the heat source circuit α via the forward pipe 6a and the backward pipe 5a is referred to as a system α. . Similarly, for example, a configuration in which refrigerant is supplied from the heat source unit 2b to each cooling unit 1b of the heat source circuit β via the forward pipe 6b and the backward pipe 5b is referred to as a system β. Similarly, for example, a configuration in which refrigerant is supplied from the heat source unit 2c to each cooling unit 1c of the heat source circuit γ via the forward pipe 6c and the backward pipe 5c is referred to as a system γ.

  In addition, as described above, in this method, a connecting portion that connects the pipes of any two heat source circuits is provided. In other words, this is a configuration that connects any two systems (the connecting portion described above). It may be called an inter-system connection section here).

  This connection part (inter-system connection part) includes a pipe for connection and one or more valves (flow rate adjusting valve V). A pipe for connection is connected to each pipe of any two heat source circuits via a flow rate adjusting valve V. For example, the connection part (inter-system connection part) between the system α and the system β in the example shown in FIG. 1 is the illustrated flow rate adjustment valves V1a, V21, V22 and the outward connection pipe 15 with respect to the outward path 6, and the return path 5 Is composed of the illustrated flow rate adjusting valve V6b and the return connection pipe 16 (in addition, it can be considered that the flow rate adjusting valves V5a, V5b, etc. are included, but this can be defined in any way depending on the concept. ).

  That is, taking the forward path as an example, the forward connection pipe 15 is connected to the forward path pipe 6a of the heat source circuit α via the flow rate adjustment valve V1a, and to the forward path pipe 6b of the heat source circuit β via the flow rate adjustment valves V21 and V22. Connected.

  Similarly, the connection part (inter-system connection part) between the system β and the system γ is the illustrated flow rate adjusting valves V1b, V23, V24, V25 and the outward connection pipe 13 with respect to the forward path pipe 6, and with respect to the return path pipe 5. The illustrated flow rate adjusting valve V6c and the return connection pipe 14 are included (the flow rate adjusting valve V5c can also be considered to be included). In other words, taking the forward path as an example, the forward path connecting pipe 13 is connected to the forward path pipe 6b of the heat source circuit β via the flow rate adjusting valves V23, V1b, and the forward path pipe of the heat source circuit γ via the flow rate adjusting valves V24, V25. It is connected to 6c.

  In addition, a forward connection pipe 11 (a pipe connected to the forward pipe 6c of the heat source circuit γ via the flow rate adjustment valve V2d), a flow rate adjustment valve V2d, and a return path connection pipe 12 (a heat source circuit γ via the flow rate adjustment valve V6d) described later. The pipe connected to the return pipe 5c) and the flow rate adjusting valve V6d may also be regarded as a connecting part (inter-system connecting part).

  By means of the inter-system connection section, it is possible to supply the refrigerant from the heat source unit 2 of one of the two systems to the heat source circuit (the cooling unit 1) of the other system. In other words, the heat source unit 2a supplies the refrigerant to the two heat source circuits (the cooling unit 1) of the heat source circuit α and the heat source circuit γ as described above by the connecting portion between the system α and the system β. It is possible. Further, the heat source unit 2b can also supply a refrigerant to two heat source circuits (the cooling unit 1) of the heat source circuit α and the heat source circuit γ by the connecting portion between the system α and the system β. In addition, the heat source unit 2b can supply the refrigerant to the heat source circuit γ (the cooling unit 1) by the connecting portion between the system β and the system γ.

  For example, taking the heat source unit 2a as an example, the heat source unit 2a is connected to the heat source circuit α (its forward pipe 6a and return pipe 5a) via the flow rate adjusting valves V2a, V4a, and V5a shown in the drawing, so that the system α The refrigerant can be supplied to the heat source circuit α (each cooling unit 1a). By setting all the flow rate adjusting valves V2a, V4a, and V5a to the “open” state, the refrigerant is supplied from the heat source unit 2a to the heat source circuit α (each cooling unit 1a). In addition to this, the connection between the system α and the system β is provided, so that the flow rate adjusting valves V1a, V21, V5b, and V6b are all in the “open” state, so that the heat source circuit β is connected to the heat source circuit β. The refrigerant is also supplied to each of the cooling units 1b.

  The other heat source units 2 are substantially the same. For example, the heat source unit 2b is connected to the heat source circuit β (its forward pipe 6b and return pipe 5b) via the illustrated flow rate adjusting valves V2b, V4b, V5b. Thus, the system β is configured, and the refrigerant can be supplied to the heat source circuit β (its respective cooling unit 1b). By setting all the flow rate adjusting valves V2b, V4b, and V5b to the “open” state, the refrigerant is supplied from the heat source unit 2b to the heat source circuit β (each cooling unit 1b).

  In addition to this, by providing the connection part between the system α and the system β, the flow rate adjusting valves V1a, V22, V6b are all opened, so that the heat source circuit α (the The refrigerant is also supplied to each cooling unit 1a). If it is desired to supply the refrigerant only from the heat source unit 2b to the heat source circuit α, the refrigerant supply to the heat source circuit β (each cooling unit 1b) can be performed by further closing the flow rate adjustment valves V2b and V5b. Just stop.

  In addition, since the connecting portion between the system β and the system γ is provided, all of the flow rate adjusting valves V1b, V24, and V6c are in the “open” state, so that the heat source circuit γ (each cooling thereof) The unit 1c) is also supplied with refrigerant.

  The heat source unit 2c is substantially the same, and is connected to the heat source circuit γ (its forward pipe 6c and return pipe 5c) via the flow rate adjusting valves V2c, V4c, V5c shown in the figure, thereby configuring the system γ. The refrigerant can be supplied to the heat source circuit γ (each cooling unit 1c). By setting all the flow rate adjusting valves V2c, V4c, and V5c to the “open” state, the refrigerant is supplied from the heat source unit 2c to the heat source circuit γ (each cooling unit 1c).

  Then, by providing the connecting part between the system β and the system γ, the flow rate adjusting valves V23, V25, V6c are all set to the “open” state, so that the heat source circuit β (each cooling thereof) The unit 1c) is also supplied with refrigerant. If it is desired to supply the refrigerant from the heat source unit 2c only to the heat source circuit β, the refrigerant supply to the heat source circuit γ (its respective cooling unit 1c) can be performed by further closing the flow rate adjusting valves V2c and V5c. Just stop.

  In addition, the heat source unit 2d, which is the standby unit 2 in FIG. 1, is connected to the heat source circuit γ (its flow control valve V2d, forward connection pipe 11, flow control valves V4d and V6d, and return connection pipe 12 through The forward pipe 6c and the backward pipe 5c) are connected. Then, by setting all the flow rate adjusting valves V2d, V4d, and V6d to the “open” state, the refrigerant is supplied to the heat source circuit γ (each cooling unit 1c).

  In the configuration example shown in FIG. 1 and the like, the refrigerant can be supplied to each other (bidirectionally) between the two systems by the inter-system connection section (connecting section), but the present invention is not limited to this example. It is good also as a structure which can supply a refrigerant | coolant only to one direction instead of bidirectional | two-way (a structural example is not shown in figure in particular). For example, in FIG. 1 etc., it is good also as a structure which can supply a refrigerant | coolant only to upper direction of a figure.

  In this case, for example, when the heat source unit 2b of the system β fails, the heat source circuit β is connected to the system β-system γ from the heat source unit 2c of the system γ below the system β in the drawing. Refrigerant is supplied through the connecting portion between the two. In addition, the refrigerant is supplied to the heat source circuit γ from the heat source unit 2d on the lower side of the system γ in the drawing. The system α remains as it is.

For example, it is good also as a structure which can supply a refrigerant | coolant only to the upper direction of a figure.
In this case, for example, when the heat source unit 2a of the system α fails, the heat source circuit α is connected to the system α-system β from the heat source unit 2b of the system β on the lower side of the system α in the drawing. Refrigerant is supplied through the connecting portion between the two. Similarly, the refrigerant is supplied to the heat source circuit β from the heat source unit 2c of the system γ on the lower side of the system β in the drawing through the connecting part between the system β and the system γ. In addition, the refrigerant is supplied to the heat source circuit γ from the heat source unit 2d on the lower side of the system γ in the drawing.

  In this way, when the failure of the heat source unit 2 occurs, the refrigerant supply destination is changed in such a manner that the refrigerant supply destination is shifted one by one (from the lower side to the upper side in the figure) one by one. Also good. Of course, this can be realized not only in one direction but also in both directions.

  Of course, it is not limited to such an example, and there may be various variations. For example, the heat source unit 2d may be connected only to the heat source circuit β, and only the heat source unit 2b may supply refrigerant to other systems. In this case, when the heat source unit 2a or 2c fails, the refrigerant is supplied from the heat source unit 2b to the heat source circuit α or γ, and is supplied from the heat source unit 2d to the heat source circuit β. When the heat source unit 2b fails, the refrigerant is supplied from the heat source unit 2d to the heat source circuit β. There are no other specific examples, but various other variations are possible.

  Here, in FIG. 1, since the heat source unit 2d is a standby unit, the flow rate adjustment valves V2d, V4d, and V6d are all in the “closed” state. The heat source unit 2d is in an operating state by causing the self-circulation circuit to function even in the standby state. This is not limited to the heat source unit 2d, but when all the heat source units 2 are in a standby state, the self-circulation circuit of the heat source unit 2 functions to stand by in an operation state.

  As described above, in this method, a self-circulation circuit is provided to keep the standby unit (here, the heat source unit 2d) in the operating state. When the standby unit (here, the heat source unit 2d) is kept in an operating state, when an abnormality occurs, the switching can be realized simply by performing the open / close switching control of the corresponding flow rate adjustment valve V, which is referred to as activation of the heat source unit 2. Since no time-consuming operation is necessary, it is possible to switch quickly.

Hereinafter, the self-circulation circuit will be described with reference to the example shown in FIG. 1, that is, the case where the heat source unit 2d is a standby unit.
The self-circulation circuit is a configuration for keeping the standby unit in an operating state as described above. Since all the heat source units 2 can be standby units in this method, the self-circulation circuit is provided in all the heat source units 2. It has been. In the example of FIG. 1, since the heat source unit 2d is a standby unit, the self-circulation circuit related to the heat source unit 2d will be described as an example, but the self-circulation circuits of the other heat source units 2 have the same configuration.

  The self-circulation circuit related to the heat source unit 2d is configured by a circulation pipe 7d, a flow rate adjusting valve V3d, an electric valve M2, and the like shown in the figure. In order to make this self-circulation circuit function, it is necessary to close the flow rate adjusting valves V2d and V4d. In this sense, the flow rate adjusting valves V2d and V4d may be regarded as a part of the self-circulating circuit.

  The circulation pipe 7d is a pipe for returning the refrigerant directly from the refrigerant discharge side to the refrigerant inflow side with respect to the heat source unit 2d. One end of the circulation pipe 7d is connected to the forward connection pipe 11 (connected at some point between the flow rate adjustment valve V2d and the heat source unit 2d), and the other end is connected to the return connection pipe 12 (flow rate adjustment valve). It is connected somewhere between V4d and the heat source unit 2d). A flow rate adjusting valve V3d and an electric valve M2 are provided on the circulation pipe 7d. The motor-operated valve M2 is a valve that can freely adjust the valve opening, unlike the flow rate adjustment valve V in only two states of “open” or “closed”.

  With the above configuration, in the standby state, as shown in FIG. 1, for example, the flow rate adjustment valves V2d and V4d are in the “closed” state, the flow rate adjustment valve V3d is in the “open” state, and the motor operated valve M2 The opening is in a state other than 0%. In this state, the heat source unit 2d is in an operating state. Thereby, the refrigerant pumped from the heat source unit 2d flows into the circulation pipe 7d, and is directly returned to the heat source unit 2d through the circulation pipe 7d. That is, the refrigerant from the heat source unit 2d is circulated around itself.

From the above, the open / close state of the flow rate adjustment valve V related to the heat source unit 2d including the self-circulation circuit will be described as follows.
That is, in the standby state, the flow rate adjustment valves V2d, V4d, and V6d are set to the “closed” state, and the flow rate adjustment valve V3d is set to the “open” state. On the other hand, when the refrigerant is supplied to the heat source circuit γ, the flow rate adjustment valves V2d, V4d, and V6d are switched to the “open” state and the flow rate adjustment valve V3d is switched to the “closed” state.

  Here, the self-circulation circuit is provided not only for the heat source unit 2d but also for all the heat source units, for example. Therefore, in the illustrated example, each heat source unit 2a, 2b, 2c is provided with a self-circulation circuit having a configuration substantially similar to the self-circulation circuit for the heat source unit 2d.

  That is, the heat source unit 2a is provided with a self-circulation circuit including the illustrated circulation pipe 7a, the flow rate adjusting valve V3a, the electric valve M1, and the like. Similarly, a self-circulation circuit including a circulation pipe 7b, a flow rate adjustment valve V3b, an electric valve M3, and the like is provided for the heat source unit 2b. For the heat source unit 2c, a self-circulation circuit including a circulation pipe 7c, a flow rate adjustment valve V3c, an electric valve M4, and the like is provided. The operation of these self-circulation circuits is substantially the same as the operation of the self-circulation circuit for the heat source unit 2d, and the description thereof is omitted here.

  However, it is not always necessary to provide a self-circulation circuit in every heat source unit 2. However, in this method, as described above, the heat source units 2 are not divided into regular units and standby (redundant) units. Therefore, for example, even if the heat source unit 2a becomes operable by repairing or replacing the heat source unit 2a after the heat source unit 2a breaks down and enters the state shown in FIG. Without returning to the standby unit again, the heat source unit 2a is set as the standby unit, and its self-circulation circuit is operated. Therefore, since it is not known which heat source unit 2 fails, basically, it is desirable to provide a self-circulation circuit in all the heat source units 2. However, as described above, the present invention is not limited to this example.

  In the configuration example shown in FIGS. 1 to 3, the connection portion connects between the heat source circuit α and the heat source circuit β (between the system α and the system β), and between the heat source circuit β and the heat source circuit γ (system β−). The system γ) is connected, and the heat source unit 2d is connected to the heat source circuit γ, but is not limited to this example. For example, the connection between the heat source circuit α and the heat source circuit γ (between the system α and the system γ) may be connected by a connecting portion, or the heat source unit 2d may be connected to the heat source circuit α, for example.

  However, it is desirable that the distance between the heat source circuits (between the systems) connected by the connecting portion and the distance between the heat source unit 2 and the heat source circuit connected to the heat source unit 2 are relatively short (close). For example, if the distance between the heat source unit 2d and each heat source circuit α, β, γ is α> β> γ (α is the farthest and γ is the closest), the heat source unit 2d is as shown in the figure. It is desirable to connect to the heat source circuit γ that is closest to the heat source circuit γ, and it is desirable not to connect to the heat source circuit α that is at least furthest away. The same applies to the heat source circuit. For example, the reason why the heat source circuit α and the heat source circuit γ are not connected in FIG. 1 is that the distance between the heat source circuit α and the heat source circuit γ is relatively long. It does not matter (of course, not limited to this example).

  In other words, in other words, it is desirable that the length of the pipe of the connecting portion be as short as possible (or as uniform as possible). That is, for example, with respect to the forward path, it is desirable that the lengths of the forward path connecting pipes 13 and 15 and the forward path connecting pipe 11 be as short as possible (or as uniform as possible). Similarly, regarding the return path, it is desirable that the lengths of the return connection pipes 14 and 16 and the forward connection pipe 12 be as short as possible (or as uniform as possible).

  As a result, the system configuration can be simplified, and the initial investment at the time of installation can be reduced. Furthermore, it is possible to safely switch the heat source unit (reducing the possibility of occurrence of any problem (for example, a problem that may occur if the piping is too long due to the refrigerant discharge pressure) when switching). it can).

Hereinafter, FIG. 1 and the like will be described in more detail.
First, as already described, in the air conditioning system of this example, a connecting portion (inter-system connecting portion) is provided between any two heat source circuits (between systems; the system d described later is also included). When a problem or the like occurs in an arbitrary heat source unit 2, first, the refrigerant supply to the predetermined heat source circuit is basically started by the standby unit (each flow rate adjusting valve V corresponding to realize this). Open / close control). This naturally starts the refrigerant supply to the heat source circuit to which the standby unit is connected (which can supply the refrigerant). In the example of FIG. 1, the refrigerant supply starts from the heat source unit 2d to the heat source circuit γ. For this purpose, for example, the opening / closing control of the flow rate adjusting valve V is performed so that the state shown in FIG. Alternatively, for example, when the heat source unit 2a becomes a standby unit after the state of FIG. 2 is reached and then any of the other heat source units 2b, 2c, 2d fails, at least the heat source circuit α is provided in the heat source unit 2a. The refrigerant supply to the engine is started (open / close control of each flow rate adjustment valve V is performed so as to realize this).

  In addition to starting the supply of the refrigerant from the standby unit, the refrigerant is further supplied from one or more of the other normal heat source units 2 to the heat source circuit of the other system via the inter-system connection section. In some cases.

  As a typical example, the refrigerant supply destination is shifted one by one as shown in FIG. That is, as shown in FIG. 2, when the heat source unit 2a fails, first, supply of refrigerant from the heat source unit 2d to the heat source circuit γ is started as described above. As a result, with respect to the heat source unit 2c that has been supplying the refrigerant to the heat source circuit γ, the refrigerant supply to the heat source circuit γ is stopped (the flow rate adjusting valves V2c and V5c are closed), and between the system β and the system γ The refrigerant supply to the heat source circuit β is started via the connecting part (intersystem connection part) (flow rate adjusting valves V23, V25, V6c are opened).

  As a result, with respect to the heat source unit 2b that has been supplying the refrigerant to the heat source circuit β, the refrigerant supply to the heat source circuit β is stopped (the flow rate adjusting valves V2b and V5b are closed), and between the system α and the system β The refrigerant supply to the heat source circuit α is started via the connecting part (intersystem connection part) (flow rate adjusting valves V1a, V22, V6b are opened).

  In this way, when the failure of the heat source unit 2 occurs, the opening / closing control of each corresponding flow rate adjustment valve V is performed so that, for example, the refrigerant supply destination from each heat source unit 2 is shifted one by one upward in the figure. (For example, by the controller 4).

  Here, the description of the configuration of FIG. 1 and the like (particularly the inter-system connection section) will be made in detail according to the concept of the system. As described above, the inter-system connection section (connecting section) is a configuration for enabling supply of refrigerant from the heat source unit 2 of any system to the heat source circuit of another system.

  For convenience of explanation, the heat source unit 2d is also regarded as one system (system d shown in the figure). This system d can be regarded as a system having no refrigerant supply destination (heat source circuit). And the structure connected to the said heat-source circuit (gamma) shall be considered as a kind of connection part (connection part) between systems. Therefore, here, the configuration including the flow rate adjustment valve V2d, the forward connection pipe 11, the flow rate adjustment valves V4d and V6d, and the return connection pipe 12 is also an intersystem connection section (intersystem connection section between the system d and the system γ). Shall be handled. Of course, it is not limited to such a concept, and it is not limited to the concept of system before that (the explanation has already been given).

First, the inter-system connection section between the system γ and the system d will be described.
First, in the system γ, the refrigerant is supplied from the heat source unit 2c to the heat source circuit γ (its respective cooling unit 1c) through the forward pipe 6c and the backward pipe 5c. Further, the illustrated flow rate adjusting valve V2c is provided on the forward path pipe 6c, and the illustrated flow rate adjusting valves V4c and V5c are provided on the return path pipe 5c. Further, an inter-system connection section between the system γ and the system d and an inter-system connection section between the system γ and the system β described later are connected to the forward pipe 6c and the return pipe 5c.

  The inter-system connection between the system γ and the system d is composed of the illustrated flow rate adjusting valves V2d, V4d, V6d, the forward connection pipe 11, the return connection pipe 12, and the like. One end of the forward connection pipe 11 is connected to the refrigerant discharge side of the heat source unit 2d, and a flow rate adjusting valve V2d is provided in the middle thereof. The other end of the outgoing connection pipe 11 is connected to the outgoing pipe 6c of the system γ in the illustrated example. The return connection pipe 12 has one end connected to the refrigerant inflow side of the heat source unit 2d, and a flow rate adjusting valve V4d is provided in the middle. As shown in the figure, the other end of the return connection pipe 12 is connected to the return pipe 5c of the system γ via a flow rate adjusting valve V6d.

  Thus, when an abnormality occurs in any heat source unit 2, for example, the opening / closing control of the corresponding flow rate adjustment valve V is performed so that the refrigerant is supplied from the heat source unit d of the system d to the heat source circuit γ of the system γ. Do. That is, by closing the flow rate adjusting valves V2c, V4c, V5c, and V3d and switching the flow rate adjusting valves V2d, V4d, and V6d to the “open” state, the heat source unit 2d → the forward connection pipe 11 → the forward pipe 6c → the return pipe. The refrigerant can be circulated through a path of 5c → return connection pipe 12 → heat source unit 2d, and the refrigerant can be supplied from the heat source unit 2d to each cooling unit 1c of the heat source circuit γ.

  Note that the refrigerant is supplied from the heat source unit d to the heat source circuit γ as described above, not only when there is an abnormality in the heat source unit 2c of the system γ, but the heat source unit 2b of the system β or the system α This can also occur when there is an abnormality in the heat source unit 2a. For example, the example of FIG. 2 described later shows a case where an abnormality has occurred in the heat source unit 2a of the system α. In this case, first, the refrigerant is supplied from the heat source unit 2b of the system β to the heat source circuit α of the system α. Further, the refrigerant is supplied from the heat source unit 2c of the system γ to the heat source circuit β of the system β. As described above, the refrigerant is supplied from the heat source unit 2d of the system d to the heat source circuit γ of the system γ. Details will be described later with reference to FIG. 2 (as described above, the refrigerant supply destination is shifted one by one upward in the figure).

  The opening / closing control of each flow rate adjustment valve V, the adjustment control of the valve opening degree of each motorized valve M, the operation / stop control of each heat source unit 2, the control of each cooling unit 1, etc. in the entire configuration shown in FIG. The illustrated controller 4 is realized. Note that this may be directly controlled by the controller 4 or indirectly. Indirect control means that, for example, each system has a controller (not shown) (not shown) that controls the entire system, and the controller 4 manages these sub-controllers in an integrated manner. Naturally, the controller 4 and each sub controller (not shown) are connected by some signal line (network, etc.), and some signal (data, command, etc.) is transmitted between the controller 4 and each sub controller via this signal line. Transmit and receive.

  Each sub-controller also monitors, for example, the state of the heat source unit 2 of its own system, and notifies the controller 4 if there is an abnormality. Thus, the controller 4 instructs each sub-controller to switch the refrigerant supply destination (opening / closing the flow rate adjusting valve V, etc.), and each sub controller opens / closes each flow rate adjusting valve V of its own system according to this instruction. Execute control. The controller 4 holds in advance data (not shown) that defines the open / close state of each flow rate adjustment valve V when there is an abnormality in the heat source unit 2 in association with each heat source unit 2, for example. Based on the data, it instructs each sub-controller to switch the open / close state of each flow rate adjustment valve V.

  Here, the controller 4 or a sub-controller (not shown) includes an arithmetic processing unit such as a microcomputer / CPU / MPU and a memory, for example. Further, the sub-controller (not shown) further transmits an opening / closing control signal, a valve opening instruction signal, various control signals, etc. to each flow rate adjusting valve V, motorized valves M1, M2 and heat source unit 2 described later. And an input interface for inputting sensor measurement values from various temperature sensors T / pressure sensors P (T1 to T4, P1 to P4, etc.) described later.

  Each sub-controller performs operation control of the heat source unit 2 and the like of the own system based on the sensor measurement value and the like of the own system, but this is an existing general control and will not be particularly described. Regarding the operation control using the self-circulation circuit of the standby unit (here, the heat source unit 2d), these measurement values are set in advance based on the sensor measurement values of the temperature sensor T2 and the pressure sensor P2, for example. The sub controller of the system d controls the heat source unit 2d so that the predetermined value is reached.

  In this description, the refrigerant temperature detected by the temperature sensors T1 and T2 may be referred to as refrigerant temperatures T1 and T2. Similarly, the refrigerant discharge pressure measured by the pressure sensors P1 and P2 may be referred to as refrigerant discharge pressures P1 and P2.

  A signal line (not shown) is connected to the output interface and the input interface, and the flow rate adjusting valve V and the temperature sensor / pressure sensor are connected to the signal line. Thus, the sub-controller transmits various signals such as opening / closing control signals of the respective flow rate adjusting valves V, inputs sensor measurement values, and the like via the signal line (not shown).

  A predetermined application program is stored in advance in the memory in the controller 4 or the sub-controller, and when the arithmetic processing unit reads and executes the application program, for example, the sub-controllers described above are managed and Open / close control of each flow rate adjusting valve V and motor-operated valves M1 and M2, various existing controls for each heat source unit 2, and the like are realized.

  1, 2, and 3, the flow rate adjusting valve V is indicated by a circle and the letters “open” or “closed” are indicated in the circle. Naturally, “open” means that the flow rate adjusting valve V is open, and “closed” means that it is closed.

  In the following description, for the sake of simplicity, the sub-controller will not be mentioned one by one (collectively controlled by the controller 4; this may be called a control device). .

Here, it returns to description of the said connection part between systems again.
The inter-system connection section between the system γ and the system d has already been described. Hereinafter, the inter-system connection section between the system α and the system β and the inter-system connection section between the system β and the system γ will be described. However, before that, first, the configuration of the system α and the system β will be briefly described (note that the configuration of the system γ has already been described, and the system α and the system β have substantially the same configuration as the system γ. is there).

  The system α is configured to supply refrigerant from the illustrated heat source unit 2a to the heat source circuit α (each cooling unit 1a) via the forward pipe 6a and the backward pipe 5a. Further, the illustrated flow rate adjusting valve V2a is provided on the forward path pipe 6a, and the illustrated flow rate adjusting valves V4a and V5a are provided on the return path pipe 5c. The inter-system connection section between the system α and the system β is connected to the forward pipe 6a and the return pipe 5a.

  Similarly, the system β is configured to supply the refrigerant from the illustrated heat source unit 2b to the heat source circuit β (each cooling unit 1b) via the forward pipe 6b and the backward pipe 5b. Further, the illustrated flow rate adjustment valve V2b is provided on the forward path pipe 6b, and the illustrated flow rate adjustment valves V4b and V5b are provided on the return path pipe 5b. Further, an inter-system connection section between the system β and the system γ and an inter-system connection section between the system α and the system β are connected to the forward pipe 6b and the return pipe 5b.

First, the inter-system connection section between the system α and the system β will be described.
The intersystem connection portion between the system α and the system β is composed of the illustrated flow rate adjusting valves V1a, V21, V22, V6b, the forward connection pipe 15, the return connection pipe 16, and the like. That is, between the system α and the system β, the forward connection pipe 15 and the flow rate adjusting valves V1a, V21, V22 are provided between the forward pipe 6a and the forward pipe 6b on the forward path side, and the return pipe 5a on the return path side. A return connection pipe 16 and a flow rate adjusting valve V6b are provided between the return pipe 5b.

The forward connection pipe 15 is connected to the forward pipe 6a via the flow rate adjustment valve V1a, and is connected to the forward path pipe 6b via the flow rate adjustment valves V21 and V22.
Regarding the forward connection pipe 15, the connection to the forward connection pipe 6b is first connected to the front and rear of the flow rate adjustment valve V2b so as to branch into the middle and sandwich the flow rate adjustment valve V2b. That is, as shown in the figure, the flow rate adjustment valve V2b is connected to the front stage (heat source unit 2b side) via the flow rate adjustment valve V22, and the flow rate adjustment valve V2b is connected to the rear stage (cooling unit 1b side). Connected through.

  In addition, the connection to the forward pipe 6a is connected to the rear stage (cooling unit 1a side) of the flow rate adjusting valve V2a via the flow rate adjusting valve V1a. However, the present invention is not limited to this example, and similarly to the connection to the forward path pipe 6b, the forward path connection pipe 15 is bifurcated in the middle and is connected before and after the flow rate adjustment valve V2a so as to sandwich the flow rate adjustment valve V2a. It may be a configuration. Of course, in this case, since the flow regulating valve V is provided in each of the bifurcated branch pipes, it is necessary to provide another flow regulating valve V on the forward connection pipe 15 in addition to the flow regulating valve V1a.

  The return connection pipe 16 is connected to the return pipe 5a through the flow rate adjusting valve V6b and to the return pipe 5b. As shown in the figure, the connection to the return pipe 5b is connected to an arbitrary position between the flow rate adjusting valve V4b and the flow rate adjusting valve V5b.

  As an example, the open / close state of each flow regulating valve V is as shown in FIG. Therefore, the flow rate adjustment valves V4a and V5a are in an open state, and the flow rate adjustment valve V6b is in a closed state. Therefore, the refrigerant returned from each cooling unit 1a of the system α through the return pipe 5a does not flow into the return connection pipe 16 in the middle, but flows into the heat source unit 2a. For example, in the state of FIG. 2 described later, the refrigerant returned from each cooling unit 1a of the system α via the return pipe 5a flows into the return connection pipe 16 in the middle, and then flows into the heat source unit 2b. become.

  Further, regarding the forward path side, in the example shown in FIG. 1, the flow rate adjustment valve V2a is open and the flow rate adjustment valve V1a is closed, so that the refrigerant does not flow in from the system β, and the heat source unit 2a A refrigerant is supplied to the cooling unit 1a.

  For example, it is assumed that the open / close state of each flow rate adjustment valve V is switched to the state shown in FIG. 2 due to the failure of the heat source unit 2a. In the state of FIG. 2, the refrigerant supply from the heat source unit 2a is blocked and the refrigerant is supplied from the heat source unit 2b of the system β to the refrigerant circuit α. FIG. 2 will be described later.

  Moreover, by setting the open / close state of the inter-system connection section between the system α and the system β, for example, as shown in FIG. 3 to be described later, the heat source unit 2a of the system α to the heat source circuit β of the system β. It can also be set as the state which supplies a refrigerant. FIG. 3 will be described later.

  As described above, with respect to the system α, the forward pipe 6a is connected to the refrigerant delivery side of the heat source unit 2a, and the return pipe 5a is connected to the refrigerant inflow side. In the default state, the heat source unit 2a supplies the refrigerant to each cooling unit 1a of the heat source circuit α by pumping the refrigerant to the forward path pipe 6a. Since the refrigerant returned from each cooling unit 1a of the heat source circuit α flows into the heat source unit 2a via the return pipe 5a, the refrigerant is cooled and pumped again to the forward pipe 6a.

  In an abnormal state, for example, the refrigerant may be supplied from the heat source unit 2a of the system α to each cooling unit 1b of the heat source circuit β. Alternatively, conversely, the refrigerant may be supplied from the heat source unit 2b of the system β to each cooling unit 1a of the heat source circuit α.

  Here, as shown in the figure, a flow rate adjusting valve V2a is provided in the vicinity of the heat source unit 2a in the forward pipe 6a. When the flow rate adjusting valve V2a is in the “open” state, a refrigerant is supplied to each cooling unit 1a of the heat source circuit α. Will be supplied. The return pipe 5a is provided with flow rate adjusting valves V4a and V5a as shown. When the flow rate adjusting valves V4a and V5a are in the “open” state, they are returned from the respective cooling units 1 of the heat source circuit α. The refrigerant flows into the heat source unit 2a.

  Further, a temperature sensor T1 and a pressure sensor P1 for measuring the temperature and discharge pressure of the refrigerant discharged from the heat source unit 2a are provided. By these sensors, the temperature of the refrigerant immediately after being sent out from the heat source unit 2a and its discharge pressure are measured.

  In the system β, the components corresponding to the flow rate adjusting valves V2a, V4a, the return pipe 5a, and the forward pipe 6a are the illustrated flow rate adjustment valves V2b, V4b, the return pipe 5b, and the forward pipe 6b. Similarly, in the system γ, the flow rate adjusting valves V2a, V4a, the return pipe 5a, and the forward pipe 6a correspond to the illustrated flow rate adjustment valves V2c, V4c, the return pipe 5c, and the forward pipe 6c.

Next, the intersystem connection part between the system β and the system γ will be described.
The inter-system connection portion between the system β and the system γ is composed of the illustrated flow rate adjusting valves V23, V1b, V24, V25, V6c, the forward connection pipe 13, the return connection pipe 14, and the like. Between the system β and the system γ, the forward connection pipe 13 and the flow rate adjusting valves V23, V1b, V24, and V25 are provided between the forward pipe 6b and the forward pipe 6c, and the backward connection is established between the return pipe 5b and the return pipe 5c. A pipe 14 and a flow rate adjustment valve V6c are provided.

The forward connection pipe 13 is connected to the forward pipe 6b via the flow rate adjustment valves V23 and V1b, and is connected to the forward path pipe 6c via the flow rate adjustment valves V24 and V25.
Regarding the forward connection pipe 13, the connection to the forward pipe 6c is first connected to the front and rear of the flow rate adjustment valve V2c so as to branch into the middle and sandwich the flow rate adjustment valve V2c. That is, as shown in the drawing, the flow rate adjusting valve V2c is connected to the front stage (heat source unit 2c side) via the flow rate adjusting valve V25, and the flow rate adjusting valve V2c is connected to the rear stage (cooling unit 1c side). Connected through.

  The connection to the forward pipe 6b is bifurcated halfway, but both of the branched pipes are connected to the subsequent stage (cooling unit 1b side) of the flow rate adjusting valve V2a (the flow rate adjusting valves V23 and V1b are connected). Connected through). Note that the connection to the forward pipe 6b is not limited to this example, and the connection to the forward pipe 6b is substantially the same as the connection to the forward pipe 6c. The bifurcated branch pipe sandwiches the flow regulating valve V2b before and after the flow regulating valve V2b. A connected configuration may be used.

  In addition, regarding the connection of the forward connection pipe 13 to the forward pipe 6b, it is not always necessary to use the two flow rate adjusting valves V23 and V1b, and only one of them may be used (in other words, bifurcated. It is also possible to connect to the forward pipe 6b without doing this (this also applies to the connection of the forward connecting pipe 13 to the forward pipe 6c).

  Further, the return connection pipe 14 is connected to the return pipe 5b of the system β via the flow rate adjusting valve V6c, and is connected to the return pipe 5c of the system γ. As shown in the figure, the return path 5c is connected to an arbitrary position between the flow rate adjusting valve V4c and the flow rate adjusting valve V5c.

  The open / closed state of each flow regulating valve V is, for example, the state shown in FIG. In this case, the flow rate adjustment valves V4b and V5b are open, and the flow rate adjustment valve V6c is closed. Therefore, the refrigerant returned from each cooling unit 1b of the system β through the return pipe 5b does not flow into the return connection pipe 14 in the middle, but flows into the heat source unit 2b. For example, in the state of FIG. 2 described later, the refrigerant returned from each cooling unit 1b of the system β through the return pipe 5b flows into the return connection pipe 14 in the middle, and then flows into the heat source unit 2c. become.

  On the forward side, since the flow rate adjustment valve V2b is open and the flow rate adjustment valves V21, V22, V23, and V1b are closed in the state shown in FIG. 1, refrigerant flows in from the other systems α and γ. In other words, the refrigerant is supplied from the heat source unit 2b to each cooling unit 1b of the own system without sending the refrigerant to the other systems α and γ.

  On the other hand, for example, in the state of FIG. 2 to be described later, the refrigerant supply from the heat source unit 2b to each cooling unit 1b of the system β is cut off, while the refrigerant sent from the heat source unit 2b passes through the forward connection pipe 15. , Are supplied to each cooling unit 1a of the system α. That is, the supply of the refrigerant to the heat source circuit of the own system is stopped and the supply of the refrigerant to the heat source circuit of the other system is started. In the case of the example in FIG. 2, the refrigerant supply to each cooling unit 1b of the system β is performed by the heat source unit 2c of the system γ. Furthermore, the refrigerant supply to each cooling unit 1c of the system γ is performed by the heat source unit 2d which was a standby unit in the example of FIG. Details will be described later.

  In addition, with regard to the configuration for connecting the systems, the configuration for connecting to the forward pipe 6b of the system β (the flow rate adjusting valves V21, V22, V23, V1b, V2b, etc.) may be referred to as a bifurcated circuit section 20 as shown in the figure. is there.

Here, a detailed configuration example of the bifurcated circuit unit 20 will be described with reference to FIG.
In FIG. 4, the same components as those shown in FIG. In other words, the flow rate adjusting valves V1b, V2b, V21, V22, V23, the forward pipe 6b, and the forward connecting pipes 13 and 15 shown in FIG. 4 are the same as those shown in FIG. .

  In this example, as shown in the figure, the four flow rate adjusting valves V connected to the forward path pipe 6b and the forward path connecting pipe 13 or 15, that is, the flow rate regulating valves V21, V22, V23, and V2b, respectively. Backflow prevention valves 31, 32, 33, and 34 are provided.

  The backflow prevention valve 31 allows the refrigerant to flow from the forward path connection pipe 15 side to the forward path pipe 6b side, and the backflow prevention valve 32 causes the refrigerant to flow from the forward path pipe 6b side to the forward path connection pipe 15 side. The backflow prevention valve 33 causes the refrigerant to flow from the forward path connecting pipe 13 side to the forward path pipe 6b side, and the backflow prevention valve 34 causes the refrigerant to flow from the forward path pipe 6b side to the forward path connecting pipe 13 side.

  In the case of the example of FIG. 4, when supplying the refrigerant from the system γ side to the system β side in FIG. 1, the flow rate adjustment valve V23 is opened. Conversely, when the refrigerant is supplied from the system β side to the system γ side, the flow rate adjustment valve V1b is opened.

  Similarly, when the refrigerant is supplied from the system α side to the system β side, the flow rate adjustment valve V21 is opened. On the contrary, when the refrigerant is supplied from the system β side to the system α side, the flow rate adjustment valve V22 is opened.

The examples shown in FIGS. 2 and 3 are the same as the example shown in FIG. 4 (therefore, for example, in FIG. 2, not the flow rate adjusting valve V1b but the flow rate adjusting valve V23 is opened). .
When the controller 4 detects a failure of any heat source unit 2, the open / close state of each flow regulating valve V is changed from the normal state shown in FIG. 1 to the abnormal state shown in FIG. 2, for example, or the abnormal state shown in FIG. And switching control. 2 and 3 show an example of the open / close state of each flow rate adjusting valve V at the time of abnormality, and the present invention is not limited to these examples.

The failure detection method for the heat source unit 2 may be an existing method, and is not particularly described here.
In addition, the controller 4 stores a flow regulating valve opening / closing table (not shown) in advance in, for example, its built-in memory. In this flow control valve opening / closing table, the open / close state of each flow control valve V corresponding to each situation is registered. For example, the open / close state shown in FIG. 1, the open / close state shown in FIG. Although the open / close state shown is registered, the present invention is not limited to these examples.

  For example, if the heat source unit 2a fails, the flow control valve V opening / closing table (not shown) in which the open / close state shown in FIG. It is programmed. This is merely an example. For example, depending on which heat source unit 2 has failed when the heat source unit 2 is in a standby state, a flow rate adjusting valve opening / closing table corresponding to each is registered. Then, referring to the flow rate adjustment valve opening / closing table corresponding to the situation at that time, the opening / closing control of each flow rate adjustment valve V is performed.

  For example, FIG. 3 to be described later can be said to show the result of opening / closing control of each flow rate adjustment valve V according to the registered contents of the table corresponding to the case where the heat source unit 2b and the heat source unit 2c fail.

The contents of the flow regulating valve opening / closing table (not shown) are arbitrarily determined in advance by, for example, a developer.
The controller 4 also operates a standby unit. For example, in the state of FIG. 1, the heat source unit 2d and its self-circulation circuit are operated. Then, adjustment control is performed so that the temperature T2 and the discharge pressure P2 of the refrigerant pumped from the heat source unit 2d are substantially the same as, for example, a predetermined refrigerant temperature and discharge pressure set in advance. Thus, when a failure occurs, the supply of refrigerant from the heat source unit 2d to another heat source circuit (the heat source circuit γ of the adjacent system γ) is quickly started without the need for starting the standby unit (heat source unit 2d). can do.

  The configuration of FIG. 1 and the like described above is, for example, “by connecting each heat source unit 2 to one or a plurality of heat source circuits via an opening / closing valve (flow rate adjusting valve V) and controlling the opening / closing of the opening / closing valve. It can also be said that it has a connection part that can supply a refrigerant to any one or more of the connected one or more heat source circuits.

  For example, if the heat source unit 2a is taken as an example, a configuration in which the refrigerant can be supplied to the heat source circuit α by connecting to the heat source circuit α (its piping 5a, 6a), and further between the “system α-system β There is a configuration in which the refrigerant can be supplied to the other heat source circuit β by connecting to the other heat source circuit β (its piping 5b, 6b) via the “inter-system connection portion”. It may be referred to as a “connection part”. The other heat source unit 2 is substantially the same as the heat source unit 2a, and basically has a connection portion that can supply the refrigerant to a plurality of heat source circuits, but the refrigerant is only in one heat source circuit γ like the heat source unit 2d. There may also be a connection that allows supply.

Here, FIG. 2 will be described.
FIG. 2 shows a state after switching the open / close state of each flow rate adjustment valve V when the heat source unit 2a fails. This is an example, and the present invention is not limited to this example.

In the example shown in FIG. 2, the open / close state of each flow rate adjustment valve V is as illustrated, and is listed below.
Closed flow control valve V; V2a, V3a, V5a, V21, V1b, V2b, V3b, V5b, V24, V2c, V5c, V3d
Open flow regulating valve V; V1a, V4a, V6b, V22, V23, V4b, V6c, V25, V4c, V6d, V2d, V4d
The meaning of the open / close state will be described below.

  First, the flow rate adjustment valves V2a and V5a are closed in order to make it possible to disconnect the failed heat source unit 2a from the system α. In addition, although the flow regulating valve V4a is in the open state in FIG. 2, this is only left as usual, and may be closed. Moreover, since it is out of order, there is no way that self-circulation can be performed, so the flow rate adjusting valve V3a is also closed.

  In addition, by setting it as the state which can be isolate | separated from a system | strain as mentioned above, the operation | work etc. which replace | exchange the heat source unit 2a which failed later with a new heat source unit can be performed easily. When the repair / replacement of the heat source unit 2a is completed, for example, the self-circulation circuit is caused to function by switching the flow rate adjusting valve V3a to an open state, and the heat source unit 2a is put on standby in an operating state.

  In addition, the heat source circuit α (each cooling unit 1a) is switched to a state in which refrigerant is supplied from the heat source unit 2b of the system β to the heat source circuit α. That is, as shown in FIG. 2, on the forward path side, the flow rate adjustment valves V22 and V1a are switched to the open state, and the flow rate adjustment valve V2b is switched to the closed state. On the return path side, the flow rate adjustment valve V6b is switched to the open state (V4b remains open), and the flow rate adjustment valve V5b is switched to the closed state.

  By setting the open / close state, the refrigerant pressure-fed from the heat source unit 2b is not supplied to the heat source circuit β of its own system, but via the flow rate adjustment valve V22, the forward connection pipe 15, and the flow rate adjustment valve V1a. It is supplied to the heat source circuit α of another system α. The refrigerant returned from the heat source circuit α through the return pipe 5a does not flow into the heat source unit 2a because the flow rate adjustment valve V5a is closed as described above, and flows through the flow rate adjustment valve V6b, the return connection pipe 16 and the like. Then, it flows into the heat source unit 2b.

  As described above, the refrigerant is supplied from the heat source unit 2b to the heat source circuit α, while the refrigerant supply from the heat source unit 2b to the heat source circuit β is stopped. Thus, this time, the refrigerant is further supplied from the heat source unit 2c of the system γ to the heat source circuit β.

  That is, as shown in FIG. 2, on the forward path side, the flow rate adjustment valves V23 and V25 are switched to the open state, and the flow rate adjustment valve V2c is switched to the closed state. On the return path side, the flow rate adjustment valve V6c is switched to the open state (V4c remains open), and the flow rate adjustment valve V5c is switched to the closed state.

  By setting the open / close state, the refrigerant pressure-fed from the heat source unit 2c is not supplied to the heat source circuit γ of its own system, but via the flow rate adjustment valve V25, the forward connection pipe 13, and the flow rate adjustment valve V23. It is supplied to the heat source circuit β (each cooling unit 1b) of the other system β. The refrigerant returned from the heat source circuit β through the return pipe 5b does not flow into the heat source unit 2b because the flow rate adjustment valve V5b is closed as described above, and flows through the flow rate adjustment valve V6c, the return connection pipe 14 and the like. Then, it flows into the heat source unit 2c.

  As described above, the refrigerant is supplied from the heat source unit 2c to the heat source circuit β, while the refrigerant supply from the heat source unit 2c to the heat source circuit γ is stopped. Thus, this time, refrigerant is supplied from the heat source unit 2d, which is a standby unit in FIG. 1, to the heat source circuit γ.

  That is, as shown in FIG. 2, the flow rate adjustment valves V2d, V4d, and V6d are switched to the open state, and the flow rate adjustment valve V3d is switched to the closed state. As a result, the self-circulation operation of the refrigerant during standby is stopped, and the refrigerant is supplied from the heat source unit 2d to the heat source circuit γ. That is, the refrigerant pumped from the heat source unit 2d is supplied to the heat source circuit γ (each cooling unit 1c) via the flow rate adjusting valve V2d, the forward connection pipe 11, and the like. Further, the refrigerant returned from the heat source circuit γ through the forward pipe 5c does not flow into the heat source unit 2c because the flow rate adjustment valve V5c is closed as described above, and the flow rate adjustment valve V6d, the return connection pipe 12 Etc., it flows into the heat source unit 2d.

  When the heat source unit 2c further fails in the state of FIG. 2, for example, the heat source unit 2b supplies refrigerant to not only the heat source circuit α of the other system but also the heat source circuit β of the own system. Good. In this case, for the forward path side, the flow rate adjustment valve V23 is closed and the flow rate adjustment valve V2b is switched to the open state. On the return path side, the flow rate adjustment valve V6c is closed and the flow rate adjustment valve V5b is switched to the open state. Of course, in this case, since one refrigerant is supplied to the two heat source circuits by one heat source unit 2, some measures such as increasing the refrigerant discharge pressure of the heat source unit 2b are required.

Next, FIG. 3 will be described below.
FIG. 3 shows an example of the open / close state of the flow rate adjustment valve V when two of the heat source units 2b and 2c fail in the state of FIG. This shows an example in which the refrigerant is supplied from the heat source unit 2a to both the heat source circuit α and the heat source circuit β.

In the example shown in FIG. 3, the open / closed states of the respective flow rate adjustment valves V are as shown in the figure, and are listed below.
Closed flow control valve V; V3a, V22, V23, V1b, V2b, V3b, V4b, V6c, V24, V2c, V3c, V5c, V3d
Open flow regulating valve V; V1a, V2a, V4a, V5a, V6b, V21, V5b, V25, V4c, V6d, V2d, V4d
V25 may be closed.

The meaning of the open / close state will be described below.
First, the failed heat source unit 2c is disconnected from the system γ and switched to the state in which the refrigerant is supplied from the heat source unit 2d, which is the standby unit in FIG. 1, to the heat source circuit γ of the system γ. Since the open / close state is the same as that in FIG. 2, only the open / close switching will be briefly described below, and a detailed description thereof will be omitted.

That is, the flow rate adjustment valve V3d is closed and the flow rate adjustment valves V2d, V4d, and V6d are switched to the open state. Further, for example, the flow rate adjusting valves V2c and V5c are closed.
Next, the systems α and β will be described below.

  First, the flow rate adjustment valves V2b and V4b are closed so that the failed heat source unit 2b can be disconnected from the system β. Then, in order to supply the refrigerant also from the heat source unit 2a to the heat source circuit β, the flow rate adjustment valves V1a and V21 are switched to the open state on the forward path side, and the flow rate adjustment valve V6b is switched to the open state on the return path side (flow rate) The adjustment valve V5b remains open).

  As a result, the refrigerant pressure-fed from the heat source unit 2a is supplied to each cooling unit 1a of the heat source circuit α via the flow rate adjusting valve V2a and the forward path pipe 6a, and a part of the refrigerant is flown in the middle of the flow rate adjusting valve V1a and the forward path. It flows into the system β side via the connecting pipe 15 and the flow rate adjusting valve V21 and is supplied to each cooling unit 1b of the heat source circuit β. Regarding the return path, the refrigerant returned from the heat source circuit α via the return path pipe 5a flows into the heat source unit 2a via the flow rate adjusting valves V5a and V4a. Further, the refrigerant returned from the heat source circuit β through the return pipe 5b merges with the refrigerant in the return pipe 5a through the flow rate adjustment valve V5b, the return connection pipe 16, and the flow rate adjustment valve V6b and flows into the heat source unit 2a. .

In this case, it is desirable to take some measures such as increasing the refrigerant discharge pressure of the heat source unit 2a.
As described above, the failed unit is repaired or replaced after being disconnected. After repair or replacement, the failed heat source unit is commissioned. After the trial run is completed, it is not necessary to return to the original state (the state shown in FIG. 1), and it is sufficient to operate in the standby state until the next failure or abnormality occurs.

  Further, even when a failure or abnormality occurs at two locations (two heat source units 2) at the same time as shown in FIG. 3, by adjusting the refrigerant flow rate with, for example, the flow rate adjusting valve V1a, one heat source unit 2a It is also possible to back up (refrigerant supply) both the heat source circuits α and β. In this case, it is assumed that the flow rate adjusting valve V1a is a valve that can freely adjust the valve opening degree, like the motor-operated valve M2 and the like.

  As described above, according to this method, since only one heat source unit needs to be provided for a plurality of heat source circuits, the cost is particularly reduced as compared with the case where a spare heat source unit is provided for each system. The effect is very large (in general, the heat source unit is very expensive).

  Further, in this method, for example, the spare heat source unit is not connected to all the systems, etc., but the flow rate adjusting valve V is connected to each heat source unit 2, for example, one or more heat source units that are relatively close to each other. For example, when an arbitrary heat source unit fails, the refrigerant can be supplied from the normal heat source unit to the heat source circuit of the own system or another system.

  If the spare heat source unit is connected to a plurality of systems, and the spare heat source unit supplies refrigerant to the system in which the heat source unit has failed, there are systems that are close in distance to the spare heat source unit. If there is a distant system, there will be a short piping length for connection, and a long one for connection. For this reason, some problems may occur regarding discharge of the refrigerant when switching to the spare heat source unit. Moreover, piping may become complicated.

  On the other hand, in this method, the length of the pipes (outward connection pipes, return connection pipes) connecting the systems can be shortened (and substantially equalized), and such a problem can be prevented from occurring. In this method, as described above, each heat source unit supplies refrigerant to a heat source circuit that is close in distance, even in the case of supplying refrigerant to a heat source circuit of another system as well as in its own system. No problem will occur. Further, the system configuration can be simplified, and the initial investment at the time of installation can be reduced.

In addition, since the heat source unit is in an operating state by the self-circulation circuit even during standby, the heat source unit can be switched safely and smoothly when a failure occurs.
Further, the reliability of the data center air conditioning equipment can be improved, and the equipment can be provided with less initial investment.

  In this method, for example, in a server room such as a data center that has a cooling system to suppress heat from the server, a heat source unit that pumps the refrigerant onto the same refrigerant circuit included in a plurality of on-off valves is used as the heat source circuit. One heat source unit, which is composed of one unit with respect to the number and does not pump the refrigerant to the heat source circuit, circulates the refrigerant on the self-circulation circuit with a discharge pressure equivalent to that of the other heat source units, and performs a standby operation. When it is determined that one or more heat source units are in failure / abnormal operation, the cooling operation of the cooling unit can be continued by switching to the refrigerant pressure feeding onto the heat source circuit. However, the number is not limited to the above plus one, and may be plus two, for example.

  As described above, the air conditioning system of the present example includes, for example, one or a plurality of cooling units that cool the air-conditioning target space with the supplied refrigerant, and an outward pipe for supplying the refrigerant to the one or more cooling units. An air conditioning system having a plurality of heat source circuits each including a plurality of heat source circuits each including a return pipe for recovering the refrigerant from the one or more cooling units, and supplying the refrigerant to any one of the plurality of heat source circuits. And has the following configuration.

First, the number of heat source units is made larger than the number of heat source circuits.
Each of the heat source units is connected to one or more heat source circuits via an on-off valve (flow rate adjusting valve V), and one of the one or more heat source circuits connected by open / close control of the on-off valve. One or more of them have a connection part that can supply the refrigerant.

  Further, when a failure occurs in any one or more of the plurality of heat source units, the opening / closing valves are opened so that the refrigerant is supplied from other heat source units to the heat source circuit to which the failed heat source unit has supplied the refrigerant. A control device that performs the closing control is provided.

  In the air conditioning system, for example, the connecting portion is connected to each of the heat source circuits to connect the forward tube / return tube to each of one or more other heat source circuits via an open / close valve. Part. In addition, the control device supplies a refrigerant to the heat source circuit supplied by the failed heat source unit from another heat source unit via the connection unit or from a heat source unit that has not supplied the refrigerant to the heat source circuit. Open / close control of the on-off valve is performed so as to be supplied.

Here, for example, it is assumed that the number of heat source units is one more than the number of heat source circuits (however, this is not limited to this example).
If there is one, there will be a heat source unit (standby unit) that is connected to the heat source circuit but not supplied with refrigerant, but if any heat source unit fails, the failed heat source unit supplies refrigerant. The heat source circuit that has been supplied is supplied with refrigerant from another heat source unit that can supply refrigerant to the heat source unit. In this case, the standby unit does not necessarily supply the refrigerant, and another heat source unit may supply the refrigerant via the connecting portion. When the other heat source unit supplies the refrigerant through the connecting portion, the standby unit may supply the refrigerant to the heat source circuit to which the heat source unit has been supplying the refrigerant. In some cases, the refrigerant is supplied from the heat source unit.

  Here, for example, at least the heat source circuits that are relatively far from each other are not connected by the connecting portion, or the standby unit is not connected to the heat source circuits that are relatively far from each other. As a result, the length of the connecting portion and the distance between the standby unit and the heat source circuit to be connected can be relatively shortened and can be substantially equalized (at least extremely long or large in length). There is no such thing as a variation).

  As a result, in this method, as already described, the lengths of the pipes (outward connection pipes and return connection pipes) connecting the systems can be made relatively short (and can be made substantially equal), and the above problems do not occur. You can In this method, as described above, each of the heat source units supplies the refrigerant to the heat source circuit that is close in distance even when supplying the refrigerant to the heat source circuit of the other system as well as the case of its own system. Such a problem does not occur. Further, the system configuration can be simplified, and the initial investment at the time of installation can be reduced.

  As described above, the length of the pipe of the connecting portion can be relatively shortened and / or substantially equalized, so that, for example, the time required for the state to stabilize at the time of switching can be shortened. Thus, the cooling target space can be stably cooled including when switching. Furthermore, if the lengths of the pipes of the connecting portion are substantially equal, effects such as a reduction in construction cost due to the pipe unit (for example, ease of mass production due to the same length) can be obtained. Conversely, it is necessary to select and install a heat source unit (an internal compressor or pump, a tank for storing refrigerant, etc.) that takes into account the variation in pipe length, maximum pipe length, and minimum length pipe. For this reason, problems such as troublesome device selection occur. Or the problem that it is necessary to introduce overspec equipment (heat source unit etc.) arises. This method can prevent such a problem from occurring.

1 (1a, 1b, 1c) Cooling unit 2 (2a, 2b, 2c, 2d) Heat source unit 4 Controller 5 (5a, 5b, 5c) Outward pipe 6 (6a, 6b, 6c) Return pipe 7 (7a, 7b, 7c, 7d) Circulation pipe 11 Outward connection pipe 12 Return connection pipe 13 Outward connection pipe 14 Return path connection pipe 15 Outward connection pipe 16 Return path connection pipe 20 Bifurcated circuit portion α, β, γ Heat source circuit (or system)
V Flow control valve M (M1, M2, M3, M4) Solenoid valve T (T1, T2, T3, T4) Temperature sensor P (P1, P2, P3, P4) Pressure sensor

Claims (8)

One or a plurality of cooling units that cool the air-conditioning target space with the supplied refrigerant, an outgoing pipe for supplying the refrigerant to the one or more cooling units, and a return pipe for collecting the refrigerant from the one or more cooling units A plurality of heat source circuits, and an air conditioning system having a plurality of heat source units that supply refrigerant to any of the plurality of heat source circuits,
The number of the heat source units is larger than the number of the heat source circuits,
Each of the heat source units is connected to one or a plurality of the heat source circuits via on / off valves, and one or more heat source circuits to which the heat source unit is connected from each heat source unit by opening / closing control of the on / off valves. A connecting portion that can supply a refrigerant to any one or more;
When a failure occurs in any one or more of the plurality of heat source units, the open / close valves are opened so that the refrigerant is supplied from another heat source unit to the heat source circuit to which the failed heat source unit is supplying the refrigerant. A control device that performs the closing control;
An air conditioning system characterized by comprising: The connecting part has a connecting part for connecting the forward pipe / return pipe to the forward pipe / return pipe of one or more other heat source circuits via the on-off valve for each of the heat source circuits. ,
The control device supplies the refrigerant to the heat source circuit supplied with the refrigerant by the failed heat source unit from another heat source unit via the connecting portion or from the heat source unit that did not supply the refrigerant to the heat source circuit. The air conditioning system according to claim 1, wherein opening / closing control of the on-off valve is performed. One or a plurality of cooling units that cool the air-conditioning target space with the supplied refrigerant, an outgoing pipe for supplying the refrigerant to the one or more cooling units, and a return pipe for collecting the refrigerant from the one or more cooling units A plurality of heat source circuits, and an air conditioning system having a plurality of heat source units that supply refrigerant to any of the plurality of heat source circuits,
The number of the heat source units is larger than the number of the heat source circuits,
By constructing a single air conditioning system by connecting any heat source unit to the forward and return pipes of any heat source circuit via an on-off valve, a plurality of air conditioning systems corresponding to the number of the heat source circuits are configured. In addition, the remaining heat source unit is connected as a standby unit to the forward pipe and the backward pipe of any one of the multiple systems via a closed connection on-off valve,
Between any two systems, an inter-system connection part that connects the forward pipes and the return pipes of the two systems via a closed connection on-off valve is provided,
When a failure occurs in a heat source unit of any one of the plurality of systems, the heat source circuit of the one system from the standby unit is switched to an open state by switching the closed connection on-off valve related to the standby unit. For each system in which the heat source unit is not malfunctioning, the closed connection on-off valve related to that system is switched to the open state by switching the heat source unit of that system to another system. An air conditioning system comprising a control device for supplying a refrigerant to a heat source circuit.   The air conditioning system according to claim 1, wherein the number of the heat source units is one more than the number of the heat source circuits. A self-circulation circuit is provided for each heat source unit,
For the standby unit that is the heat source unit that has not failed but does not supply the refrigerant to the heat source circuit, the control device sets the standby unit in an operating state and performs self-circulation of the refrigerant through the self-circulation circuit. The air conditioning system according to any one of claims 1 to 4, wherein   The control device supplies the refrigerant to the heat source circuit so that the refrigerant is supplied from another heat source unit to the heat source circuit supplied by the other heat source unit via the connecting portion. 3. The air conditioning system according to claim 2, wherein opening / closing control of the on-off valve is performed so that the refrigerant is supplied from the heat source unit that has not existed.   The air conditioning system according to claim 2, wherein at least the heat source circuits that are relatively far from each other are not connected by the connecting portion. 3. The air conditioning system according to claim 2, wherein at least systems that are relatively far from each other are not connected to each other by the inter-system connection section, and / or the standby unit is not connected to systems that are relatively far from each other. .