JP2006207928A - Refrigeration air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigeration air conditioning system capable of preventing ignition and fire spreading when an inflammable refrigerant leaks in a system using the inflammable refrigerant and a fire extinguishing refrigerant. <P>SOLUTION: In the refrigeration air conditioning system, a substantial part of a heat source machine 5 is composed by a primary side first refrigerant circuit comprised by connecting a compressor 1, a heat source machine side heat exchanger 2, a throttling device 3, and a common heat exchanger 4 by a refrigerant piping. A substantial part of an indoor unit 9 is composed by a secondary side second refrigerant circuit comprised by connecting a secondary side refrigerant pump 6, a throttling device 7, an indoor unit side heat exchanger 8, and the common heat exchanger 4 by a refrigerant pipe. In the system, heat exchange is carried out between the first refrigerant circuit and the second refrigerant circuit via the common heat exchanger 4, the inflammable refrigerant is used in the first refrigerant circuit, and the fire extinguishing refrigerant is used in the second refrigerant circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a large-scale refrigeration air conditioning system applied to, for example, a building air conditioning system, and more particularly to a system using a combustible refrigerant and a fire extinguishing refrigerant.

  Conventional refrigeration and air conditioning systems have used refrigerants that contribute to the suppression of ozone depletion as a global environmental problem, but have not yet suppressed global warming. Examples of such refrigerants that suppress global warming include hydrocarbon refrigerants and carbon dioxide, which are natural refrigerants, and R32 single refrigerant, which has a lower global warming coefficient than conventional refrigerants R22 and R407C. It is done. A refrigerating and air-conditioning system using a mixed refrigerant of carbon dioxide and a hydrocarbon refrigerant such as propane having high azeotropy with carbon dioxide is also known in Patent Document 1 below.

Japanese Patent Laid-Open No. 2002-235072 (see FIG. 2)

By the way, hydrocarbon refrigerant and R32 are combustible. In addition, the operating pressure of the natural refrigerant is very high compared to conventional R407C and R22. For this reason, when the refrigerant leaks inside the refrigerant-use product device in which the electric parts are arranged or in a room to be air-conditioned, the refrigerant is likely to spread to the surroundings due to the high momentum of the refrigerant jet. In a system using such flammable refrigerants or high-pressure operating refrigerants, if the surroundings are exposed to an abnormally high temperature due to a fire or the like, ignition of refrigerating machine oil exposed to air, indoor oxygen concentration There is a risk of fire deterioration and fire spread.
In addition, in the case of a system having a plurality of use side (indoor unit side) heat exchangers, there are indoor units in the middle of the branched refrigerant pipes. Depending on the shape of the part, lubricating oil (for example, refrigerating machine oil) for driving parts such as a compressor tends to stay in the refrigerant piping of some indoor units. In addition, a refrigerant whose condensing pressure exceeds the refrigerant critical point tends to always become a two-phase refrigerant at the outlet of the condenser during cooling operation. For this reason, if there are a plurality of branch pipes, the refrigerant distribution becomes non-uniform, and the lubricating oil tends to stay together with the refrigerant in some branch circuits. Furthermore, if a branch from the outlet of the condenser to the plurality of indoor units passes through the refrigerant pipe, the same drift is likely to occur. In such a case, there is a risk that a branch circuit having an extremely small refrigerant flow rate may be generated, and the retention of lubricating oil is likely to occur due to a decrease in flow velocity accompanying the decrease in flow rate. If the refrigerant leaks in such a situation, the lubricating oil staying at the same time is likely to leak, but if this lubricant is flammable refrigerating machine oil, etc., the possibility of ignition after the leakage increases. . And when using a natural refrigerant | coolant with a high operating pressure, since the ejection range becomes wider than conventional R22, R407C, etc., possibility that it will eject and refrigeration oil will contact an ignition source becomes high.

  In order to solve the above-described problems of the prior art, a refrigerating and air-conditioning system according to the present invention has a plurality of refrigerant circuits independent from each other, and transfers heat between the plurality of refrigerant circuits via a common heat exchanger. In the refrigerating and air-conditioning system to be performed, a flammable refrigerant is used in one refrigerant circuit, and a fire extinguishing refrigerant is used in another refrigerant circuit.

Moreover, it has two refrigerant circuits independent from each other, exchanges heat between the two refrigerant circuits via a common heat exchanger, and constitutes a heat source unit with one refrigerant circuit, and uses the other refrigeration circuit In a refrigeration and air conditioning system in which a heat exchanger is arranged indoors, a combustible refrigerant is used for the refrigerant circuit on the heat source unit side, and an extinguishing refrigerant is used for the refrigerant circuit on the indoor side.

And in the refrigerating and air-conditioning system having a plurality of refrigerant circuits independent from each other, and using the use side heat exchanger of each refrigerant circuit in the common indoor unit, a combustible refrigerant is used for a certain refrigerant circuit, and other refrigerant circuits It uses fire extinguishing refrigerant.

Further, a refrigerant containing a fire extinguishing refrigerant is used in the refrigerant circuit, and the refrigerant circuit is provided with refrigerant discharge means for releasing the refrigerant in the refrigerant circuit to the outside.

Further, in the above configuration, when a refrigerant circuit using a refrigerant containing a fire extinguishing refrigerant is provided with air injection means for injecting air into the refrigerant circuit, and the refrigerant in the refrigerant circuit is released to the outside by the refrigerant discharge means In addition, air is injected into the refrigerant circuit by the air injection means.

Then, the compressor, the heat source device side heat exchanger, the first expansion device, and the first usage side heat exchanger are sequentially connected in an annular manner to form a refrigerant circuit, and between the heat source device side heat exchanger and the first expansion device. Is provided with a branch circuit connecting the refrigerant circuit between the first use side heat exchanger and the compressor, and the branch circuit is provided with a second expansion device and a second use side heat exchanger, and stored in the compressor. In the refrigerating and air conditioning system in which the combustible lubricating oil that has been circulated in the refrigerant circuit and the branch circuit during system operation, the refrigerant used in the refrigerant circuit and the branch circuit is the high pressure of the refrigerant circuit and the branch circuit. It is a natural refrigerant that becomes a supercritical state under the conditions, and is a fire extinguishing refrigerant.
The present invention also includes a refrigeration and air conditioning system having three or more refrigerant circuits independent from each other. However, if the use side heat exchanger of a certain refrigerant circuit is the first use side heat exchanger, the remaining two or more refrigerant circuits are used. All the use side heat exchangers shall be referred to as second use side heat exchangers.

Further, the refrigerant circuit using the flammable refrigerant is provided with a fire extinguishing refrigerant injection means for injecting the fire extinguishing refrigerant into the refrigerant circuit, the fire extinguishing refrigerant injected into the refrigerant circuit by the fire extinguishing refrigerant injection means, and a flammable A refrigerant is used in combination.

Moreover, in each above-mentioned structure, a fire extinguishing refrigerant | coolant is a carbon dioxide.

  According to the refrigerating and air-conditioning system of the present invention, among a plurality of independent refrigerant circuits, the use of a flammable refrigerant in a certain refrigerant circuit and the use of a fire extinguishing refrigerant in another refrigerant circuit make it possible to generate electricity. The degree of freedom of arrangement in consideration of safety is increased such that a refrigerant circuit using a fire extinguishing refrigerant can be arranged in an installation area where there are many mechanical parts or a room where a user lives. Also, in the case of a combustible refrigerant leak in a shared heat exchanger that transfers heat between refrigerant circuits, or in a shared indoor unit that simultaneously incorporates use side heat exchangers of a plurality of refrigerant circuits, Since the extinguishing refrigerant is likely to leak at the same time, it contributes to prevention of fire and suppression of fire spread.

  In addition, the use of a flammable refrigerant in the refrigerant circuit on the heat source unit and the use of an extinguishing refrigerant in the refrigerant circuit on the indoor side may cause the refrigerant to ignite even if the refrigerant circuit is damaged and the refrigerant leaks. There is no sex. On the contrary, when the refrigerant leaks due to an indoor fire or the like, the leaked refrigerant plays the role of a digestive agent, which can suppress the spread of fire and eventually lead to fire extinguishing.

In addition, before the refrigerant pressure becomes abnormal, such as when the ambient temperature rises abnormally by providing a refrigerant discharge means for releasing the refrigerant to the surroundings in the refrigerant circuit that uses the refrigerant containing the extinguishing refrigerant. The pressure can be reduced in advance. Even when the ambient temperature rises due to a fire, the spread of fire can be suppressed because the released refrigerant acts as a fire extinguishing agent.

  Furthermore, after discharging the refrigerant containing the extinguishing refrigerant, the outside air is injected into the refrigerant circuit, so that the injected air is transported through the refrigerant circuit and jetted into the refrigerant discharge destination space. Thereby, it can prevent that the oxygen concentration of the space of a refrigerant | coolant discharge | release destination falls more than necessary.

In a refrigeration and air conditioning system having a plurality of usage-side heat exchangers, each usage-side heat exchanger exists in each branch circuit branched from the refrigerant circuit by a refrigerant pipe. Flammable lubricating oil may stay in the refrigerant piping. When the accumulated lubricating oil leaks from the refrigerant pipe, the fire extinguishing refrigerant also leaks at the same time, so that ignition from the combustible lubricating oil can be prevented.

By using a combustible refrigerant such as a hydrocarbon-based refrigerant and a fire extinguishing refrigerant such as carbon dioxide in combination, global warming can be significantly suppressed as compared with conventional general-purpose R407C and the like.

  Furthermore, global warming can be suppressed by using carbon dioxide as a fire extinguishing refrigerant. In addition, since the operating pressure in the refrigerant circuit is higher for carbon dioxide than for R32, the extinguishing carbon dioxide is more likely to leak before the flammable R32, which is effective in preventing the spread of fire. .

Embodiment 1 FIG.
FIG. 1 shows an embodiment of the present invention. In FIG. 1, 1 is a compressor, 2 is a heat source machine side heat exchanger, 3 is a throttle device, 4 is a common heat exchanger, 5 is a heat source machine, 6 is a secondary refrigerant pump, and 7 is a secondary side throttle device. , 8 are indoor unit side heat exchangers, and 9 is an indoor unit.
In the present embodiment, the main part of the heat source unit 5 is configured by a primary first refrigerant circuit in which the compressor 1, the heat source unit side heat exchanger 2, the expansion device 3, and the common heat exchanger 4 are connected by refrigerant piping. Has been. The secondary side refrigerant pump 6, the secondary side expansion device 7, the indoor unit side heat exchanger 8, and the common heat exchanger 4 are connected to each other by a secondary side second refrigerant circuit, and the indoor unit 9 The main part is configured.
The first refrigerant circuit and the second refrigerant circuit are independent from each other, and heat is transferred between the circuits via the common heat exchanger 4. And the hydrocarbon (propane: flammable refrigerant | coolant) whose global warming potential (TEWI) is smaller than R22 or R407C is used for the 1st refrigerant circuit by the side of the heat source machine 5. On the other hand, carbon dioxide (extinguishing refrigerant) having a global warming potential (TEWI) smaller than R22 or R407C is used for the second refrigerant circuit on the indoor unit 9 side. The arrows in FIG. 1 indicate the flow direction of the refrigerant, which is a refrigeration cycle system that cools the indoor unit side.

According to the refrigerating and air-conditioning system of this embodiment, in the event that flammable propane leaks in the shared heat exchanger 4, the carbon dioxide flowing through the same shared heat exchanger 4 is likely to leak at the same time. Therefore, fire extinguishing carbon dioxide leaks and dilutes combustible propane, so that propane is prevented from being ignited, or even if ignited and burned, the spread of fire to the surroundings is suppressed. In addition, there is a high degree of freedom in arrangement in consideration of safety such that a refrigerant circuit using a fire extinguishing refrigerant can be arranged in an installation area where there are many electromechanical parts that emit sparks or in a room where a user lives. Become.
And since carbon dioxide is enclosed and used in a circuit by using carbon dioxide as a fire extinguishing refrigerant | coolant, global warming can be suppressed. Further, since the operating pressure in the refrigerant circuit is higher in carbon dioxide than in R32, the extinguishing carbon dioxide is more likely to leak before the flammable R32, which is more effective in preventing the spread of fire.

In addition, since many switches that can easily spark are provided in the heat source machine, a system using a fire extinguishing refrigerant in the first refrigerant circuit and a combustible refrigerant in the second refrigerant circuit is also included in the present invention. Needless to say. Further, the present invention includes three or more refrigerant circuits that are independent from each other, and that transfers heat between these three or more refrigerant circuits via a common heat exchanger.

Embodiment 2. FIG.
FIG. 2 shows an embodiment of the present invention. 1a and 1b are compressors, 2a and 2b are heat source side heat exchangers, 3a and 3b are expansion devices, 5a and 5b are heat source units, 8a and 8b are indoor unit side heat exchangers, and 9A is an expansion device 3a and a room. This is a shared indoor unit in which the machine side heat exchanger 8a and the expansion device 3b and the indoor unit side heat exchanger 8b are arranged in the same casing. In this embodiment, the compressor 1a, the heat source unit side heat exchanger 2a, the expansion device 3a, and the indoor unit side heat exchanger 8a are connected by a refrigerant pipe to form a first refrigerant circuit, and the compressor 1b, the heat source unit side heat The second refrigerant circuit is configured by connecting the exchanger 2b, the expansion device 3b, and the indoor unit side heat exchanger 8b with refrigerant piping. The first refrigerant circuit and the second refrigerant circuit are independent of each other. In this case, HFC32, which is a flammable refrigerant, is used for the first refrigerant circuit on the heat source unit 5a side, and carbon dioxide, which is a fire extinguishing natural refrigerant, is used for the second refrigerant circuit on the side of the heat source unit 5b. Moreover, the refrigerant | coolant discharge | release means 10b is attached to the upstream of the expansion device 3a in the refrigerant circuit by the side of the heat source machine 5b in which the extinguishing refrigerant is used. Several types of refrigerant discharge means 10b are conceivable. For example, a fusible plug that automatically melts and releases the refrigerant when the refrigerant temperature (saturation temperature) reaches a predetermined value, or the temperature and pressure of the refrigerant, the indoor temperature detected by the temperature sensor 17, and the radiant heat A control valve that automatically opens and discharges a refrigerant when a command from the control device 18 is given, or an external fire alarm, smoke detector, combustible refrigerant leak detector A control valve that receives a signal from the control device 18 and automatically opens the valve to release the refrigerant is exemplified as the refrigerant discharge means.

In this way, a plurality of types of refrigerants that are less affected by global warming are used, one is a flammable refrigerant, the other is a fire extinguishing refrigerant, and the fire extinguishing refrigerant is automatically released from the refrigerant circuit under certain conditions. With such a configuration, the pressure can be reduced before the refrigerant pressure becomes abnormal, such as when the ambient temperature rises abnormally. Also, when the ambient temperature rises due to a fire or the like, the discharged refrigerant acts as a fire extinguisher. That is, even when the flammable refrigerant leaks, it is possible to quickly ignite the flammable refrigerant and prevent fire spread by releasing the fire-extinguishing refrigerant, and thus it is possible to realize a refrigeration and air conditioning system with excellent safety.
In the present embodiment, the HFC 32 is taken as an example of the combustible refrigerant, but similar effects can be obtained even when propane, which is a hydrocarbon-based natural refrigerant, is used instead. The refrigerant discharge means 10b is installed in the shared outdoor unit 9A, but the same refrigerant discharge means 10A is also attached to the heat source unit 5b, and the refrigerant discharge destination of the refrigerant discharge unit 10A is set in the heat source unit 5a. The same action and effect are exhibited against leakage of the combustible refrigerant in the heat source unit 5a.

Embodiment 3 FIG.
FIG. 3 shows an embodiment of the present invention. In FIG. 3, 1 is a compressor, 2 is a heat source side heat exchanger, 3 is a throttle device, 5 is a heat source unit, 8 is an indoor unit side heat exchanger, 9 is an indoor unit, and 10 is a refrigerant in the refrigerant circuit. An indoor unit side on-off valve (an example of a refrigerant discharge unit) that discharges indoors, and 11 is a heat source unit side on-off valve (an example of an air injection unit) that injects air around the heat source unit 5 into the refrigerant circuit. The heat source unit 5 and the indoor unit 9 are connected via a refrigerant pipe.

In the present embodiment, carbon dioxide (extinguishing refrigerant), which is a natural refrigerant, is used as the refrigerant. The refrigeration and air conditioning system of FIG. 3 is a system in which the heat source unit 5 and the indoor unit 9 are connected by a refrigerant pipe, so that the system has a high degree of freedom in installation. And in the refrigerant circuit, the refrigeration oil which is the lubricating oil of the compressor sliding part partially discharged from the compressor 1 circulates. The refrigerating machine oil used in this embodiment is a combustible oil. In this case, the longer the refrigerant pipe, the more refrigeration oil is present in the refrigerant circuit. However, the refrigeration oil is preliminarily sealed so that the refrigeration oil remaining in the compressor 1 is not exhausted. For this reason, when a refrigerant | coolant leaks by piping crack etc., refrigeration oil may jet widely with a refrigerant | coolant. However, since carbon dioxide, which is a fire extinguishing refrigerant, is used in this system, carbon dioxide is also released together with the refrigeration oil from the leakage portion, so that there is almost no risk of ignition.
On the other hand, if the controller 21 is configured to open the valve of the indoor unit side opening / closing valve 10 in conjunction with the fire occurrence signal from the fire alarm device 20, even if a fire occurs in the room, Carbon dioxide, which is a fire extinguishing gas, is ejected indoors. Thereby, it is possible to prevent the fire from spreading. At the same time, the pressure sensor 19 detects that the pressure in the refrigerant circuit has decreased due to the discharge of the refrigerant, and the control device 21 opens the heat source apparatus side on-off valve 11. In this case, since the heat source apparatus side opening / closing valve 11 is connected to the refrigerant circuit (for example, the suction side of the compressor 1), the compressor 1 is operated when the pressure in the refrigerant circuit falls below the ambient pressure (usually atmospheric pressure). The ambient air is sucked in from the heat source unit side opening / closing valve 11 by the driving of the heat source unit 11 and compressed, and is conveyed toward the indoor unit 9 in the refrigerant circuit. In the indoor unit 9, since the indoor unit side opening / closing valve 10 is open, the conveyed air is ejected into the room where the refrigerant is discharged. Air has already been extinguished by the release of fire-extinguishing refrigerant, and air is supplied to it, so that the oxygen concentration in the room rises and prevents the oxygen concentration from dropping more than necessary. Is secured. Therefore, in the refrigeration cycle using a high-pressure refrigerant, if the refrigeration oil is widely scattered when the refrigerant leaks, it is possible to prevent the spread of fire even if ignition occurs. In a multi-system in which a plurality of indoor units 9 are connected in parallel, all indoor units 9 are provided with the same indoor unit side opening / closing valve 10 and selectively open one as necessary. It is also possible.

Embodiment 4 FIG.
FIG. 4 shows an embodiment of the present invention. In FIG. 4, 1 is a compressor, 2 is a heat source side heat exchanger, 3a is a second expansion device, 3b is a first expansion device, 5 is a heat source unit, and 8a is a second indoor unit side (use side) heat exchange. 8b is a first indoor unit side (use side) heat exchanger, 9a is a second indoor unit, 9b is a first indoor unit, 15 is a four-way valve that switches between a cooling and a heating refrigerant circuit, and 16 is a branch. Circuit. In addition, A shows the branch part where a refrigerant branches with respect to the two indoor units 9a and 9b, and B shows the merge part where the refrigerant from the two indoor units 9a and 9b merges.
In this embodiment, a compressor circuit, a heat source unit side heat exchanger 2, a first expansion device 3b, and a first indoor unit side heat exchanger 8b are sequentially connected in an annular manner through a refrigerant pipe to form a refrigerant circuit. Yes. The branch circuit 16 connects the refrigerant circuit between the heat source unit side heat exchanger 2 and the first expansion device 3b and the refrigerant circuit between the first indoor unit side heat exchanger 8b and the compressor 1. The branch circuit 16 is provided with a second expansion device 3a and a second indoor unit side heat exchanger 8a. In this embodiment, carbon dioxide is used as the refrigerant, and flammable ether oil is used as the refrigerating machine oil (lubricating oil) of the compressor 1.

The arrow in FIG. 4 has shown the flow direction of the refrigerant | coolant at the time of heating operation. The refrigerant discharged from the compressor 1 is in a critical state, reaches the branching section A through the four-way valve 15 as it is, branches at the branching section A, and the first indoor unit 9b of the refrigerant circuit and the second of the branching circuit 16 After exchanging heat at the indoor unit 9a and joining at the junction B, the heat is returned to the compressor 1 via the heat source unit side heat exchanger 2. At this time, a part of the refrigerating machine oil stored in the compressor 1 is discharged together with the refrigerant, circulates through the refrigerant circuit and the branch circuit 16 via the branch part A and the junction part B, and passes through the heat source machine side heat exchanger 2. Return to the compressor 1.
Here, considering the case where the second indoor unit 9a is stopped and the first indoor unit 9b is operating, for example, the second expansion device 3a in the second indoor unit 9a is fully closed. Accordingly, the refrigerant flows into the first indoor unit 9b, and the indoor units 9a and 9b can be individually air-conditioned.
In such a case, a part of the refrigerating machine oil that has flown before stays in the branch circuit 16 and the second indoor unit side heat exchanger 8a that are directed from the branch part A to the stopped second indoor unit 9a. In addition, in this portion, there is a refrigerant that does not flow but is in a state higher than the critical pressure (so-called supercritical state). Such a supercritical refrigerant is easy to dissolve in refrigerating machine oil because it has both the characteristics of a gas that easily enters a narrow gap and the characteristics of a liquid that is easily dissolved. For this reason, the fluidity of the refrigerating machine oil staying in the refrigerant pipe or the heat exchanger is increased. In such a situation, if a refrigerant leak occurs in the stopped second indoor unit 9a or the front and rear branch circuits 16, refrigerating machine oil with high fluidity is likely to blow out. However, since fire extinguishing carbon dioxide also leaks at the same time, the flammability of the refrigerating machine oil is suppressed, and problems such as fire can be minimized.
On the other hand, when the capacity of the compressor 1 is controllable and the refrigerant flow rate can be adjusted by the load on the first indoor unit 9b side, if the refrigerant flow rate decreases, Also, the refrigerating machine oil tends to stay in the refrigerant circuit extending from the branch portion A to the first indoor unit 9b. However, since it has carbon dioxide, which is a digestible refrigerant, it exhibits a fire suppression effect against refrigerant leakage similar to the second indoor unit 9a that is stopped as described above. In this way, it is possible to provide a device that is useful in a system in which the plurality of indoor units 9a and 9b can be individually operated, and the compressor 1 has a variable capacity and the refrigerant flow rate increases or decreases.

  In addition, in this embodiment, the example which provided one branch circuit in parallel with respect to the refrigerant circuit which has one compressor 1 was shown, However, Two or more branch circuits were connected in parallel with the said refrigerant circuit. Are also included in the present invention. The indoor unit, the expansion device, and the indoor unit side heat exchanger in the branch circuit in that case are also referred to as the second indoor unit, the second expansion device, and the second indoor unit side heat exchanger of the present invention, respectively.

Embodiment 5. FIG.
FIG. 5 shows an embodiment of the present invention. In FIG. 5, 1 is a compressor, 2 is a heat source side heat exchanger, 3 is an expansion device, 5 is a heat source unit, 8 is an indoor unit side heat exchanger, 9 is an indoor unit, and 12 is a fire extinguishing refrigerant. A container filled with carbon, 13 is a pressure sensor for detecting the low pressure of the refrigerant circuit, and 14 is an on-off valve for injecting carbon dioxide in the container 12 into the refrigerant circuit (an example of a fire extinguishing refrigerant injection means). .

In this embodiment, propane, which is a flammable refrigerant, is normally used as the refrigerant. When it is detected that the propane has leaked to the outside (for example, when the pressure sensor 13 detects a low pressure lower than a predetermined value), the control device 22 opens the on-off valve 14 to store carbon dioxide, which is a fire extinguishing refrigerant, in the container. 12 is injected into the refrigerant circuit and used together with propane. In this way, while normally ensuring stable operation with a single refrigerant, in the event of an emergency such as leakage, mixing fire extinguishing refrigerant, while causing a decrease in operational stability due to multiple refrigerants with different operating characteristics, A safe device that prioritizes fire prevention can be provided. In addition, as described above, by using a combustible refrigerant such as a hydrocarbon refrigerant and a fire extinguishing refrigerant such as carbon dioxide, it is possible to significantly suppress global warming compared to conventional general-purpose R407C and the like. Become.
In FIG. 5, the container 12 and the on-off valve 14 are installed inside the heat source unit 5. However, even when these units are installed inside the indoor unit 9, the same effect is exhibited. The operation of the on-off valve 14 may employ a configuration such as interlocking with a fire alarm 23 provided in the indoor unit 9 or a fire alarm 24 provided in the heat source unit 5.

  As an example of use of the present invention, it is extremely effective as an air conditioning system for a space which is a large building and has many partitions on a high floor, which makes it difficult for fire fighting activities.

It is a refrigerant circuit figure of the refrigerating and air-conditioning system concerning Embodiment 1 of the present invention. It is a refrigerant circuit figure of the refrigerating air-conditioning system concerning Embodiment 2 of the present invention. It is a refrigerant circuit figure of the refrigerating air-conditioning system concerning Embodiment 3 of the present invention. It is a refrigerant circuit figure of the refrigerating air-conditioning system concerning Embodiment 4 of the present invention. It is a refrigerant circuit figure of the refrigerating air-conditioning system concerning Embodiment 5 of the present invention.

Explanation of symbols

1, 1a, 1b Compressor, 2, 2a, 2b Heat source side heat exchanger, 3, 3a, 3b Expansion device, 4 Common heat exchanger, 5, 5a, 5b Heat source unit, 6 Secondary side refrigerant pump, 7 Secondary side expansion device, 8, 8a, 8b Indoor unit side heat exchanger, 9, 9a, 9b Indoor unit, 9A Shared indoor unit, 10 Indoor unit side on / off valve, 10b Refrigerant discharge means, 11 Heat source unit side on / off valve, 12 containers, 14 on-off valves, 16 branch circuits, 18 control devices, 21 control devices, 22 control devices.

Claims (8)

In a refrigerating and air-conditioning system having a plurality of refrigerant circuits independent of each other and transferring heat between the plurality of refrigerant circuits via a common heat exchanger, a combustible refrigerant is used for a certain refrigerant circuit, A refrigerating and air-conditioning system using a fire extinguishing refrigerant in another refrigerant circuit. Two refrigerant circuits that are independent of each other, transfer heat between the two refrigerant circuits via a common heat exchanger, one refrigerant circuit constitutes a heat source unit, and the use side heat of the other refrigeration circuit A refrigerating and air conditioning system in which an exchanger is disposed indoors, wherein a combustible refrigerant is used in the refrigerant circuit on the heat source unit side, and an extinguishing refrigerant is used in the refrigerant circuit on the indoor side. In a refrigeration and air conditioning system that has a plurality of refrigerant circuits independent from each other, and uses a heat exchanger for each refrigerant circuit in a shared indoor unit, a flammable refrigerant is used in one refrigerant circuit and the other refrigerant circuit is extinguished. Refrigerating and air-conditioning system characterized by using a functional refrigerant. A refrigerating and air-conditioning system characterized in that a refrigerant containing a fire extinguishing refrigerant is used in a refrigerant circuit, and refrigerant discharge means for releasing the refrigerant in the refrigerant circuit to the outside is provided in the refrigerant circuit. An air injection means for injecting air into the refrigerant circuit is provided in a refrigerant circuit using a refrigerant containing a fire extinguishing refrigerant, and the air injection is performed when the refrigerant in the refrigerant circuit is discharged to the outside by the refrigerant discharge means. 5. The refrigerating and air-conditioning system according to claim 4, wherein air is injected into the refrigerant circuit by means. A refrigerant circuit is formed by sequentially connecting a compressor, a heat source device side heat exchanger, a first expansion device, and a first usage side heat exchanger in an annular shape, and between the heat source device side heat exchanger and the first expansion device. And a branch circuit that connects the refrigerant circuit between the first use side heat exchanger and the compressor, a second expansion device and a second use side heat exchanger are provided in the branch circuit, In the refrigerating and air-conditioning system in which combustible lubricating oil stored in the compressor circulates through the refrigerant circuit and the branch circuit during system operation, the refrigerant used in the refrigerant circuit and the branch circuit is: A refrigerating and air-conditioning system, which is a natural refrigerant that becomes a supercritical state under a high pressure condition of the refrigerant circuit and the branch circuit, and is a fire extinguishing refrigerant. A fire extinguishing refrigerant injection means for injecting a fire extinguishing refrigerant into the refrigerant circuit is provided in the refrigerant circuit using the combustible refrigerant, the fire extinguishing refrigerant injected into the refrigerant circuit by the fire extinguishing refrigerant injection means, and the flammability A refrigerating and air-conditioning system characterized by using a refrigerant together. The refrigeration air conditioning system according to any one of claims 1 to 7, wherein the fire extinguishing refrigerant is carbon dioxide.

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