WO2016016999A1 - Refrigeration cycle device - Google Patents

Abstract

This refrigeration cycle device (100) forms a coolant circuit by being filled with a coolant that comprises a substance having the property of causing a disproportional reaction, and a refrigerator oil that is compatible with the coolant. At least a first heat exchanger or a second heat exchanger comprises a plurality of heat-transfer pipes 43 and a header 47 or 48. The internal diameter of the header 47 or 48 is greater than the internal diameter of the heat-transfer pipe 43, and the end section on the coolant outlet side of the heat-transfer pipe 43 is disposed so as to face a pipe inner wall surface 50 of the header. The end section on the coolant outlet side of the heat-transfer pipe 43 is located at a position such that the value of L/d is less than 20 and greater than 0 if the distance from the center 45 or 46 of the end section on the coolant outlet side of the heat-transfer pipe 43 to the pipe inner wall surface 50 of the header corresponding to the center 45 or 46 is the distance L and the inner diameter or equivalent diameter at the end section on the coolant outlet side of the heat-transfer pipe 43 is the inner diameter d.

Description

Refrigeration cycle equipment

The present invention relates to a refrigeration cycle apparatus such as an air conditioner applied to, for example, a building multi-air conditioner.

In a refrigeration cycle apparatus that forms a refrigerant circuit that circulates refrigerant and performs air conditioning, such as a multi air conditioner for buildings, generally, R410A that is nonflammable, hydrogen and carbon such as propane that exhibits flammability A substance containing is used as a refrigerant. When these substances are released into the atmosphere, they have different lifetimes until they are decomposed in the atmosphere and changed to other substances. However, they are highly stable in the refrigeration cycle apparatus and have been used for a long period of several decades. It can be used as a refrigerant.

On the other hand, some substances containing hydrogen and carbon have poor stability in the refrigeration cycle apparatus and are difficult to use as refrigerants. These substances having poor stability include, for example, substances that cause a disproportionation reaction. Disproportionation is the property that substances of the same type react to change to another substance. For example, when some strong energy is applied to the refrigerant in a state where the distance between adjacent substances such as a liquid state is very close, this energy causes a disproportionation reaction, and the adjacent substances react with each other, It changes to another substance. When a disproportionation reaction occurs, heat is generated and a rapid temperature rise occurs. As a result, the pressure may increase rapidly. For example, if a substance that causes a disproportionation reaction is used as a refrigerant in a refrigeration cycle device and is enclosed in a pipe such as copper, the pipe cannot withstand the pressure rise of the internal refrigerant, and the pipe will burst. Accidents may occur. As substances having such a disproportionation reaction, for example, 1,1,2-trifluoroethylene (HFO-1123), acetylene and the like are known.

There is also a thermal cycle system (refrigeration cycle apparatus) using 1,1,2-trifluoroethylene (HFO-1123) as a working medium for thermal cycle (for example, Patent Document 1).

JP 2014-098166 A (Fig. 1 etc.)

Patent Document 1 describes that 1,1,2-trifluoroethylene (HFO-1123) is used as a working medium for a heat cycle in a refrigeration cycle apparatus such as a heat cycle system. 1,1,2-trifluoroethylene (HFO-1123) is a substance having a disproportionation reaction. Therefore, when used as a refrigerant as it is, a disproportionation reaction may occur due to some energy at a place in the refrigerant circuit where a liquid substance such as a liquid or a two-phase adjacent substance flows very close. When adjacent substances disproportionate, they change to another substance and do not function as a refrigerant. In addition, in the refrigerant circuit, an accident such as a pipe rupture may occur due to a sudden pressure increase. For this reason, in order to use a substance having a disproportionation reaction as a refrigerant, there is a problem that the disproportionation reaction must not be caused. Thus, a device for preventing this disproportionation reaction is required, but Patent Document 1 and the like do not describe any method for realizing an apparatus that does not cause the disproportionation reaction.

The present invention has been made to solve the above-described problem, and a refrigeration cycle that can safely use a substance having a property of causing a disproportionation reaction by reducing energy received from the outside of the refrigerant as a refrigerant. Get the device.

A refrigeration cycle apparatus according to the present invention is composed of a substance having a property of causing a disproportionation reaction by connecting a compressor, a first heat exchanger, a throttling device, and a second heat exchanger with a refrigerant pipe. A refrigerant circuit is formed by charging a single refrigerant or a mixed refrigerant containing a substance having a property of causing a disproportionation reaction and a refrigerating machine oil having compatibility with the refrigerant to form a first heat exchanger and a second heat exchanger. At least one of the heat exchangers has a plurality of heat transfer tubes through which the refrigerant flows, and a header through which the refrigerant outlet side end of the heat transfer tubes is inserted, and the inner diameter of the header is that of the heat transfer tubes. The end of the heat transfer tube on the side of the refrigerant outlet that is larger than the inner diameter is disposed so as to face the inner wall surface of the header, and from the center of the end of the heat transfer tube on the side of the refrigerant outlet, the end of the header corresponding to the center L is the distance to the wall surface, the inner diameter at the end of the heat transfer tube on the refrigerant outlet side, or The equivalent diameter corresponding to the diameter when the inner diameter d, the value of L / d is, at a position of 20 and less than 0, greater than one in which the ends of the refrigerant outlet side of the heat transfer tube is located.

According to the refrigeration cycle apparatus of the present invention, when a refrigerant circuit is formed using a substance having a property of causing a disproportionation reaction such as 1,1,2-trifluoroethylene (HFO-1123) as a refrigerant, By adjusting the impact applied to the inner wall surface of the pipe, disproportionation reaction is less likely to occur, and it is impossible to use it as a refrigerant or to prevent accidents such as pipe rupture, and use it safely as a refrigerant Can be obtained.

Schematic which shows the example of installation of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. The circuit block diagram which shows an example of the circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. The refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of the air_conditionaing | cooling operation mode of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. The refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of the heating operation mode of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. The solubility diagram of the refrigeration oil of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. Schematic of the structure of the heat exchanger used for the heat source side heat exchanger 12, the load side heat exchanger 15, etc. in Embodiment 1 of this invention. Sectional drawing which shows the relationship between the header 47 used for the heat exchanger of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention, and the heat exchanger tube 43. FIG. Schematic of another structure of the heat exchanger of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. Schematic of another structure of the heat exchanger of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. The schematic diagram of the heat exchanger tube used for the heat exchanger of the refrigerating cycle device concerning Embodiment 1 of the present invention. The circuit block diagram of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention.

Hereinafter, a refrigeration cycle apparatus according to an embodiment of the invention will be described with reference to the drawings. Here, in FIG. 1 and the following drawings, the same reference numerals denote the same or corresponding parts, and are common to the whole text of the embodiments described below. And the form of the component represented to the whole text of specification is an illustration to the last, Comprising: It does not limit to the form described in the specification. In particular, the combination of the components is not limited to the combination in each embodiment, and the components described in the other embodiments can be applied to another embodiment. Further, when there is no need to particularly distinguish or identify a plurality of similar devices that are distinguished by subscripts, the subscripts may be omitted. In the drawings, the size relationship of each component may be different from the actual one. The level of temperature, pressure, etc. is not particularly determined in relation to absolute values, but is relatively determined in the state, operation, etc. of the system, apparatus, and the like.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating an installation example of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. The refrigeration cycle apparatus shown in FIG. 1 can select either a cooling mode or a heating mode as an operation mode by configuring a refrigerant circuit that circulates refrigerant and using the refrigerant refrigeration cycle. Here, the refrigeration cycle apparatus of the present embodiment will be described by taking an air conditioning apparatus that performs air conditioning of the air-conditioning target space (indoor space 7) as an example.

1, the refrigeration cycle apparatus according to the present embodiment has one outdoor unit 1 that is a heat source unit and a plurality of indoor units 2. The outdoor unit 1 and the indoor unit 2 are connected by an extension pipe (refrigerant pipe) 4 that conducts the refrigerant, and the cold or warm heat generated in the outdoor unit 1 is delivered to the indoor unit 2 via the extension pipe 4. It is like that.

The outdoor unit 1 is usually arranged in an outdoor space 6 that is a space outside a building 9 such as a building (for example, a rooftop), and supplies cold or hot heat to the indoor unit 2. The indoor unit 2 is disposed at a position where the temperature-adjusted air can be supplied to the indoor space 7 which is a space inside the building 9 (for example, a living room). Air is supplied.

As shown in FIG. 1, in the refrigeration cycle apparatus according to the present embodiment, an outdoor unit 1 and each indoor unit 2 are connected to each other using two extension pipes 4.

Here, FIG. 1 shows an example in which the indoor unit 2 is a ceiling cassette type, but the present invention is not limited to this. Any type may be used as long as heating air or cooling air can be blown directly into the indoor space 7 by a duct or the like, such as a ceiling-embedded type or a ceiling-suspended type.

Further, in FIG. 1, the case where the outdoor unit 1 is installed in the outdoor space 6 is shown as an example, but the present invention is not limited to this. For example, the outdoor unit 1 may be installed in an enclosed space such as a machine room with a ventilation opening. Further, if the waste heat can be exhausted outside the building 9 by the exhaust duct, it may be installed inside the building 9. Furthermore, you may make it install in the inside of the building 9 using the water-cooled outdoor unit 1. FIG. No matter what place the outdoor unit 1 is installed, no particular problem occurs.

Further, the number of connected outdoor units 1 and indoor units 2 is not limited to the number shown in FIG. 1, and the number of units can be determined according to the building 9 in which the refrigeration cycle apparatus according to the present embodiment is installed. That's fine.

FIG. 2 is a circuit configuration diagram showing an example of a refrigerant circuit configuration of the refrigeration cycle apparatus (hereinafter referred to as the refrigeration cycle apparatus 100) according to the first embodiment. Based on FIG. 2, the detailed structure of the refrigerating-cycle apparatus 100 is demonstrated. As shown in FIG. 2, the outdoor unit 1 and the indoor unit 2 are connected by an extension pipe (refrigerant pipe) 4 through which a refrigerant flows.

[Outdoor unit 1]
The outdoor unit 1 is mounted with a compressor 10, a first refrigerant flow switching device 11 such as a four-way valve, a heat source side heat exchanger 12, and an accumulator 19 connected in series by a refrigerant pipe.

The compressor 10 sucks in the refrigerant, compresses the refrigerant, discharges it in a high temperature and high pressure state.
The compressor 10 has, for example, a low-pressure shell structure that has a compression chamber in a sealed container, the inside of the sealed container has a low-pressure refrigerant pressure atmosphere, and sucks and compresses the low-pressure refrigerant in the sealed container. Alternatively, a high-pressure shell structure is used in which the inside of the sealed container becomes a high-pressure refrigerant pressure atmosphere and the high-pressure refrigerant compressed in the compression chamber is discharged into the sealed container. About the compressor 10 of this Embodiment, it is good to comprise by the inverter compressor etc. which can control capacity | capacitance, for example. The first refrigerant flow switching device 11 switches the refrigerant flow during the heating operation and the refrigerant flow during the cooling operation. The heat source side heat exchanger 12 serving as the first heat exchanger functions as an evaporator during heating operation and functions as a condenser (or radiator) during cooling operation. The heat source side heat exchanger 12 exchanges heat between air supplied from a blower (not shown) and the refrigerant, and evaporates or condenses the refrigerant. The heat source side heat exchanger 12 functions as a condenser in the operation of cooling the indoor space 7. Moreover, in the case of the driving | operation which heats the indoor space 7, it functions as an evaporator. The accumulator 19 is provided on the suction side of the compressor 10 and stores excess refrigerant in the refrigerant circuit due to an operation mode change or the like.

Further, the outdoor unit 1 is provided with a high pressure detection device 37, a low pressure detection device 38, and a control device 60. The control device 60 controls devices based on detection information from various detection devices, instructions from a remote controller, and the like. For example, the driving frequency of the compressor 10, the rotation speed of the blower (including ON / OFF), the switching of the first refrigerant flow switching device 11 and the like are controlled, and each operation mode described later is executed. Here, the control device 60 of the present embodiment is constituted by a microcomputer having a control arithmetic processing means such as a CPU (Central Processing Unit). Moreover, it has a memory | storage means (not shown) and has the data which made the process procedure regarding control etc. a program. Then, the control arithmetic processing means executes processing based on the program data to realize control. The high-pressure detection device 37 is installed in the discharge side piping of the compressor 10 that has a high pressure in the refrigerant circuit. Further, the low-pressure detection device 38 is installed in a pipe on the refrigerant inflow side of the accumulator 19 that has a low pressure in the refrigerant circuit. The high pressure detection device 37 and the low pressure detection device 38 transmit a signal based on the detected pressure to the control device 60. The control device 60 controls each device of the outdoor unit 1 based on the pressure detected by processing the transmitted signal.

[Indoor unit 2]
The indoor unit 2 is equipped with a load-side heat exchanger 15 serving as a second heat exchanger. The load side heat exchanger 15 is connected to the outdoor unit 1 by the extension pipe 4. The load-side heat exchanger 15 performs heat exchange between air supplied from a blower (not shown) and the refrigerant, and generates heating air or cooling air to be supplied to the indoor space 7. The load side heat exchanger 15 acts as a condenser in the case of an operation for heating the indoor space 7. Moreover, in the case of the driving | running which cools the indoor space 7, it acts as an evaporator. Here, although not illustrated, each indoor unit 2 has a control device that controls the devices in the indoor unit 2.

FIG. 2 shows an example in which four indoor units 2 are connected, and are illustrated as an indoor unit 2a, an indoor unit 2b, an indoor unit 2c, and an indoor unit 2d from the bottom of the page. Further, according to the indoor unit 2a to the indoor unit 2d, the load side heat exchanger 15 is also loaded from the lower side of the page with the load side heat exchanger 15a, the load side heat exchanger 15b, the load side heat exchanger 15c, and the load side heat exchange. It is shown as a container 15d. Here, as in FIG. 1, the number of indoor units 2 connected is not limited to the four shown in FIG.

Next, each operation mode executed by the refrigeration cycle apparatus 100 will be described. The refrigeration cycle apparatus 100 determines the operation mode of the outdoor unit 1 to be either the cooling operation mode or the heating operation mode based on an instruction from each indoor unit 2. That is, the refrigeration cycle apparatus 100 can perform the same operation (cooling operation or heating operation) for all of the indoor units 2 and adjusts the indoor temperature. Here, in both the cooling operation mode and the heating operation mode, each indoor unit 2 can be operated / stopped freely.

The operation mode executed by the refrigeration cycle apparatus 100 includes a cooling operation mode in which all the driven indoor units 2 perform a cooling operation (including a stop), and all of the driven indoor units 2 are in a heating operation. There is a heating operation mode for executing (including stopping). Below, each operation mode is demonstrated with the flow of a refrigerant | coolant.

[Cooling operation mode]
FIG. 3 is a refrigerant circuit diagram illustrating a refrigerant flow when the refrigeration cycle apparatus 100 is in the cooling operation mode. In FIG. 3, the cooling operation mode will be described by taking as an example a case where a cooling load is generated in all the load-side heat exchangers 15. In FIG. 3, a pipe indicated by a thick line indicates a pipe through which the refrigerant flows, and a flow direction of the refrigerant is indicated by a solid line arrow.

When performing the operation in the cooling operation mode shown in FIG. 3, in the outdoor unit 1, the control device 60 switches the first refrigerant flow path so that the refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12. Switch the device 11. The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11. The refrigerant that has flowed in is condensed and liquefied while dissipating heat to the outdoor air in the heat source side heat exchanger 12, becomes a high-pressure liquid refrigerant, and flows out of the outdoor unit 1.

The high-pressure liquid refrigerant that has flowed out of the outdoor unit 1 passes through the extension pipe 4 and flows into each of the indoor units 2 (2a to 2d). The high-pressure liquid refrigerant that has flowed into the indoor unit 2 (2a to 2d) flows into the expansion device 16 (16a to 16d), and is throttled and decompressed by the expansion device 16 (16a to 16d). It flows out as a phase refrigerant. The refrigerant that has passed through the expansion device 16 (16a to 16d) flows into each of the load side heat exchangers 15 (15a to 15d) acting as an evaporator, and absorbs heat from the air circulating around the load side heat exchanger 15. Thus, it becomes a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flows out of the indoor unit 2 (2a to 2d), flows into the outdoor unit 1 again through the extension pipe 4, passes through the first refrigerant flow switching device 11, and passes through the accumulator 19. Then, it is sucked into the compressor 10 again.

At this time, the opening degree (opening area) of the expansion devices 16a to 16d is determined based on the detected temperature of the load-side heat exchanger gas refrigerant temperature detection device 28 and the control device 60 of each outdoor unit 2 from the control device 60 of the outdoor unit 1 (FIG. It is controlled so that the temperature difference (superheat degree) between the evaporation temperature transmitted by communication to the target value (not shown) approaches the target value.

Here, it is assumed that all the indoor units 2 perform the cooling operation. However, when the cooling operation mode is executed, it is not necessary to flow the refrigerant to the load-side heat exchanger 15 (including the thermo-off) having no heat load. For this reason, the indoor unit 2 stops operation. At this time, the expansion device 16 corresponding to the stopped indoor unit 2 is fully closed or set to a small opening at which the refrigerant does not flow.

[Heating operation mode]
FIG. 4 is a refrigerant circuit diagram illustrating a refrigerant flow when the refrigeration cycle apparatus 100 is in the heating operation mode. In FIG. 4, the heating operation mode will be described by taking as an example a case where a thermal load is generated in all the load-side heat exchangers 15. In FIG. 4, a pipe indicated by a thick line indicates a pipe through which the refrigerant flows, and a flow direction of the refrigerant is indicated by a solid line arrow.

When performing the operation in the heating operation mode shown in FIG. 4, in the outdoor unit 1, the control device 60 uses the first refrigerant flow switching device 11, the refrigerant discharged from the compressor 10, and the heat source side heat exchanger 12. It switches so that it may flow into indoor unit 2 without going through. The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant, passes through the first refrigerant flow switching device 11, and flows out of the outdoor unit 1. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into each of the indoor units 2 (2a to 2d) through the extension pipe 4. The high-temperature and high-pressure gas refrigerant that has flowed into the indoor unit 2 (2a to 2d) flows into the load-side heat exchanger 15 (15a to 15d) and circulates around the load-side heat exchanger 15 (15a to 15d). It liquefies while radiating heat to the air, and becomes a high-temperature and high-pressure liquid refrigerant. The high-temperature and high-pressure liquid refrigerant that has flowed out of the load-side heat exchanger 15 (15a to 15d) flows into the expansion device 16 (16a to 16d), is throttled and decompressed by the expansion device 16 (16a to 16d), It becomes a low-pressure two-phase refrigerant and flows out of the indoor unit 2 (2a to 2d). The low-temperature and low-pressure two-phase refrigerant that has flowed out of the indoor unit 2 flows into the outdoor unit 1 again through the extension pipe 4.

At this time, the opening degree (opening area) of the expansion devices 16a to 16d is determined based on the condensation temperature transmitted from the control device 60 of the outdoor unit 1 to the control device (not shown) of each indoor unit 2 through communication, Control is performed such that the temperature difference (degree of supercooling) from the detected temperature of the heat exchanger liquid refrigerant temperature detecting device 27 approaches the target value.

The low-temperature and low-pressure two-phase refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12, absorbs heat from the air flowing around the heat source side heat exchanger 12, and evaporates to form a low-temperature and low-pressure gas refrigerant or low-temperature and low-pressure. It becomes a two-phase refrigerant with a large dryness. The low-temperature and low-pressure gas refrigerant or the two-phase refrigerant is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

When the heating operation mode is executed, it is not necessary to flow the refrigerant to the load-side heat exchanger 15 (including the thermo-off) that has no heat load. However, in the heating operation mode, if the expansion device 16 corresponding to the load-side heat exchanger 15 having no heating load is fully closed or has a small opening at which the refrigerant does not flow, the load-side heat exchanger of the indoor unit 2 that is not operating. In 15, the refrigerant is cooled and condensed by the ambient air, the refrigerant accumulates, and the refrigerant circuit as a whole may fall short of the refrigerant. Therefore, during heating operation, the opening degree (opening area) of the expansion device 16 corresponding to the load-side heat exchanger 15 having no heat load is set to a large opening degree such as full opening to prevent accumulation of refrigerant.

As described above, in the refrigeration cycle apparatus 100, when the indoor unit 2 is performing the cooling operation, the heat source side heat exchanger 12 acts as a condenser, and the heat source side heat exchanger 12 has a high-temperature and high-pressure gas. The refrigerant flows in and condenses, liquefies through a two-phase region, and flows out as a high-temperature and high-pressure liquid refrigerant. Further, when the indoor unit 2 is performing the heating operation, the load side heat exchanger 15 (15a to 15d) acts as a condenser, and the load side heat exchanger 15 (15a to 15d) The refrigerant flows in and condenses, liquefies through a two-phase region, and flows out as a high-temperature and high-pressure liquid refrigerant.

[Type of refrigerant]
When the refrigerant used in the refrigeration cycle apparatus 100 is a substance that is generally used as a refrigerant, such as R32, R410A, etc., a device for improving the stability of the refrigerant in the refrigerant circuit. It can be used as it is, without applying. However, here, as a refrigerant, a disproportionation reaction such as 1,1,2-trifluoroethylene (HFO-1123) represented by C ₂ H ₁ F ₃ and having one double bond in the molecular structure is performed. It is assumed that a single refrigerant composed of a substance having a property of generating or a mixed refrigerant obtained by mixing another substance with a substance having a property of causing a disproportionation reaction is used. It should be noted that not only the refrigerant containing HFO-1123 but also any refrigerant containing a substance having a property of causing a disproportionation reaction is applicable to the refrigerant used in the refrigeration cycle apparatus according to the present invention. It becomes.

Table to generate a mixed refrigerant, as the material to be mixed to the material properties causing disproportionation reaction, for example, in tetrafluoropropene _(CF 3 CF = CH ₂ in which the chemical formula of C ₃ H ₂ F ₄ HFO-1234yf which is 2,3,3,3-tetrafluoropropene, HFO-1234ze which is 1,3,3,3-tetrafluoro-1-propene represented by CF ₃ CH═CHF), Difluoromethane (HFC-32) whose chemical formula is represented by CH ₂ F ₂ is used. However, the substance mixed with the substance having a disproportionation reaction is not limited to these. For example, HC-290 (propane) or the like may be mixed. Any material having thermal performance that can be used as a refrigerant of the refrigeration cycle apparatus 100 may be used. Further, the mixing ratio may be any mixing ratio.

If a substance that causes a disproportionation reaction is used as a refrigerant as it is, the following problems occur. For example, in a place where there is a substance in a liquid state where the distance between adjacent substances is very close, such as a liquid phase, two phases, etc., if some strong energy is applied, the adjacent substances react to each other and become It will change and will not function as a refrigerant. In addition, there is a possibility that an accident such as a pipe rupture may occur due to a rapid pressure rise due to heat generation. Therefore, in order to use a substance having a disproportionation reaction as a refrigerant, in a refrigerant circuit, a liquid part in which a liquid liquid refrigerant flows or a gas-liquid two-phase refrigerant in a mixed state of gas and liquid flows. In the two-phase part, it is necessary to devise so as not to cause this disproportionation reaction. Here, the collision energy when the refrigerant and the structure collide also causes a disproportionation reaction of the refrigerant. For this reason, if the components of the refrigerant circuit have a structure in which the collision energy is reduced, disproportionation reaction hardly occurs.

[Refrigerator oil]
The refrigerating machine oil filled in the refrigerant circuit is mainly composed of either polyol ester or polyvinyl ether, and a part of the refrigerating machine oil filled in the compressor 10 circulates in the refrigerant circuit together with the refrigerant. To do. Both the polyol ester and the polyvinyl ether are refrigerating machine oils that are easily soluble in a refrigerant having one double bond in the molecular structure. When this refrigerating machine oil and HFO-1123 as a refrigerant are mixed, HFO-1123 is dissolved to some extent in the refrigerating machine oil. The refrigerating machine oil is not limited to this as long as it is compatible with the refrigerant, and another type of oil may be used.

FIG. 5 is a solubility diagram of the refrigerating machine oil of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. High solubility means that many refrigerants are dissolved in the refrigeration oil, and low solubility means that only a small amount of refrigerant is dissolved in the refrigeration oil. FIG. 5 shows the relationship between the solubility and the pressure for each of the refrigerant temperatures T1, T2, and T3. Here, in FIG. 5, T1, T2, and T3 are different temperatures, and the formula (1) is established.

[Equation 1]
T1 <T2 <T3 (1)

As shown in FIG. 5, under the same pressure condition, the lower the refrigerant temperature, the higher the solubility, and under the same temperature condition, the higher the refrigerant pressure, the higher the solubility. When the refrigerant is dissolved in the refrigerating machine oil, the refrigerating machine oil molecules are present between the refrigerant molecules. Therefore, if the solubility of the refrigerant in the refrigerating machine oil is large, the refrigerating machine oil exists between many refrigerant molecules. As described above, the refrigerant disproportionation reaction is a phenomenon in which adjacent refrigerant molecules react with each other. For this reason, if the refrigerating machine oil having compatibility with the refrigerant is used, the refrigerant oil molecules are present between the refrigerant molecules, so that the disproportionation reaction of the refrigerant hardly occurs.

And the greater the solubility of the refrigerant in the refrigeration oil, the greater the effect of suppressing the disproportionation reaction of the refrigerant. Practically, if the solubility is 50 wt% (weight%) or more, many refrigerants are dissolved in the refrigerating machine oil, so that the disproportionation reaction can be suppressed.

[Heat source side heat exchanger 12 or load side heat exchanger 15 (15a to 15d)]
FIG. 6 is a diagram showing an outline of the configuration of a plate fin tube type heat exchanger used in the heat source side heat exchanger 12, the load side heat exchanger 15 (15a to 15d) and the like in the first embodiment of the present invention. is there. In FIG. 6, a plate fin tube type heat source side heat exchanger 12 or load side heat exchanger 15 (here, referred to as heat exchanger 12 or 15) includes a first connection pipe 41, a second connection pipe 42, and a surrounding area. It has a heat transfer tube 43, fins 44, a first header 47, and a second header 48 for exchanging heat between air or the like as a heat medium and an internal refrigerant.

The configuration of the heat exchanger 12 or 15 will be described in more detail. The heat exchanger 12 or 15 has a configuration in which a plurality of fins 44 are arranged at intervals, and a plurality of heat transfer tubes 43 are arranged through the plurality of fins 44. One end of both ends of the plurality of heat transfer tubes 43 is connected to the first header 47, and the other end of the heat transfer tubes 43 is connected to the second header 48. In addition, a first connection pipe 41 and a second connection pipe 42 that serve as refrigerant inlets and outlets from other devices in the refrigerant circuit are connected to the first header 47 and the second header 48, respectively.

The first header 47 or the second header 48 distributes the refrigerant flowing from the first connection pipe 41 or the second connection pipe 42 to each heat transfer pipe 43. In addition, the refrigerant that flows in from the heat transfer tubes 43 is joined. FIG. 6 shows a case where there is one first header 47 and one second header 48, and the same number of heat transfer tubes 43 are connected to each of the first header 47 and the second header 48.

In FIG. 6, the solid line arrow indicates the direction of refrigerant flow when the heat exchanger 12 or 15 acts as a condenser, and the broken line arrow indicates the case where the heat exchanger 12 or 15 acts as an evaporator. The direction in which the refrigerant flows is shown. This also applies to FIGS. 8 and 9 described later.

When the heat exchanger 12 or 15 acts as a condenser, a high-temperature and high-pressure gas refrigerant flows into the heat exchanger 12 or 15. The high-temperature and high-pressure gas refrigerant that has flowed into the heat exchanger 12 or 15 from the first connection pipe 41 is distributed by the first header 47 and flows into the heat transfer pipes 43. The heat transfer tube 43 and the fins 44 are condensed by exchanging heat with surrounding air and the like, and liquefied through a two-phase region in which gas and liquid are mixed to become a high-temperature and high-pressure liquid refrigerant. From the second header 48, and flows into the second connection pipe 42.

On the other hand, when the heat exchanger 12 or 15 acts as an evaporator, a low-temperature and low-pressure two-phase refrigerant flows into the heat exchanger 12 or 15. The low-temperature and low-pressure two-phase refrigerant that has flowed into the heat exchanger 12 or 15 from the second connection pipe 42 is distributed by the second header 48 and flows into the heat transfer pipes 43. The heat transfer tubes 43 and fins 44 evaporate by exchanging heat with the surrounding air and the like, and the dryness of the two-phase refrigerant increases, resulting in a two-phase refrigerant or gas refrigerant with a low temperature and low pressure and high dryness. It flows out from the heat pipe 43, merges at the first header 47, and flows out to the first connection pipe 41.

In the heat exchanger 12 or 15, when the flow rate of the refrigerant flowing inside the heat transfer tube 43 becomes too large, the pressure loss of the refrigerant in the heat transfer tube 43 becomes too large. For this reason, there is a limit to the flow rate of the refrigerant that can flow with respect to the inner diameter of one heat transfer tube 43. Therefore, when the heat transfer tube 43 is thin, it is necessary to increase the number of the heat transfer tubes 43 in order to flow the refrigerant at the same flow rate as when the heat transfer tube 43 is thick. In addition, the heat transfer tube 43 has a larger heat transfer area of the heat transfer tube 43 with respect to the flow rate of the refrigerant flowing inside, and the performance of the heat exchanger 12 or 15 is improved. Therefore, in the heat exchanger 12 or 15, the heat transfer tube 43 having a thin outer diameter such as 7 mm or 5 mm is usually used. When the thin heat transfer tube 43 is used, the heat exchanger 12 or 15 is configured using the plurality of heat transfer tubes 43, and the first connection tube 41 or the second connection tube 42 (here, the connection tube 41 or 42) is required to be distributed or merged with the plurality of heat transfer tubes 43. Although there are several methods for distributing or joining the refrigerant, the first header 47 or the second header 48 (here, referred to as the header 47 or 48) is used. It is general because it can. The header 47 or 48 is connected to a plurality of heat transfer tubes 43 and is distributed or merged. The header 47 or 48 is often composed of a circular tube thicker than the heat transfer tubes 43. However, the header 47 or 48 may have any structure as long as it can distribute or merge the refrigerant of the plurality of heat transfer tubes 43. For example, the cross section may be rectangular, elliptical, or the like. The material may also be copper, aluminum or the like. What is necessary is just to have the intensity | strength which can endure the pressure concerning the inflow / outflow of a refrigerant | coolant.

FIG. 7 is a cross-sectional view showing the relationship between the header 47 or 48 and the heat transfer tube 43 used in the heat exchanger of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. A plurality of heat transfer tubes 43 are inserted into the header 47 or 48. Since FIG. 7 shows a cross section, the heat transfer tube 43 appears to be one, but the heat transfer tube 43 overlaps in a direction perpendicular to the paper surface. Actually, a plurality of heat transfer tubes 43 are connected to one header 47 or 48.

As described above, when the heat exchanger 12 or 15 acts as a condenser, a high-pressure liquid refrigerant flows into the second header 48. Moreover, when the heat exchanger 12 or 15 acts as an evaporator, it may flow into the first header 47 of the low-pressure two-phase refrigerant. The inner diameter of the header 47 or 48 is larger than the outer diameter of the heat transfer tube 43. A hole is made in the side surface of the header 47 or 48 to insert the heat transfer tube 43, and the header 47 or 48 and the heat transfer tube 43 are fixed by brazing or the like. Since the refrigerant flowing into the header 47 or 48 has an inertial force, it collides with the pipe inner wall surface (inner surface) 50 of the header 47 or 48 facing the center 45 or 46 of the outlet 45 (refrigerant outlet) of the heat transfer tube 43. The direction of flow in a substantially perpendicular direction can be changed. If the refrigerant flowing into the header 47 or 48 collides with the inner surface 50 of the header 47 or 48 when the collision energy is large, the collision energy causes a disproportionation reaction for a substance that causes a disproportionation reaction. May be a factor. Therefore, in the present embodiment, conditions (use of compatible refrigerating machine oil) are provided for the refrigerant to be used so as to suppress the disproportionation reaction.

The collision energy between the inner surface 50 of the header 47 or 48 and the refrigerant is obtained by the equation (2).

[Equation 2]
Collision energy = Refrigerant mass x Refrigerant speed change = (Refrigerant mass flow rate x Unit time) x Refrigerant speed change (2)

As described above, the disproportionation reaction is a property in which the same type of substances react with each other and change into different substances. This disproportionation reaction is likely to occur when some strong energy is applied from the outside in a state where the distance between adjacent substances such as liquid components and two-phase liquid components is very close. On the other hand, in the gas state, the distance between the refrigerant molecules is considerably longer than in the liquid state. For this reason, in the gas state, even if a large amount of HFO-1123, which is a substance that causes a disproportionation reaction, is included, the disproportionation reaction is unlikely to occur.

Here, the behavior of the jet of refrigerant flowing into the header 47 or 48 from the pipe will be examined. When the length of the inner diameter of the pipe is d (mm) and the distance from the outlet of the pipe to the collision surface of the jet flowing out from the outlet is L (mm), the following points are generally known in fluid mechanics: Yes. For example, when the value of (L / d) obtained by dividing the distance L by the inner diameter d is less than a predetermined value, the turbulence component of the jet is large, and when the value of (L / d) is greater than or equal to the predetermined value, the turbulence of the jet The components disappear and the flow is completely stabilized. It is also widely known that the predetermined value is 20-30. Therefore, when the value of (L / d) is less than 20, turbulence remains in the jet. When the inner diameter d and the distance L are applied to the heat transfer tube 43 and the inner surface 50 of the header 47 or 48 facing the heat transfer tube 43, the inner diameter d becomes the inner diameter of the heat transfer tube 43 as shown in FIG. Further, the distance L is the distance from the center 45 or 46 of the outlet of the heat transfer tube 43 to the inner surface 50 of the header 47 or 48 and the portion facing the center 45 or 46 of the outlet of the heat transfer tube 43.

As described above, when a refrigerant having the property of causing a disproportionation reaction and a refrigerating machine oil having compatibility are mixed, a refrigerating machine oil molecule exists between the refrigerant molecules. Disproportionation reaction is difficult to occur. For this reason, when the heat exchanger 12 or 15 acts as a condenser, the liquid refrigerant that has flowed out of the heat transfer tube 43 collides with the inner surface 50 of the second header 48, and the inner surface 50 collides with the inner surface 50. Even if the refrigerant is disturbed, the disproportionation reaction due to collision is unlikely to occur. The same applies to the case where the heat exchanger 12 or 15 acts as an evaporator and the two-phase refrigerant flowing out of the heat transfer tube 43 collides with the inner surface 50 of the first header 47. Therefore, if the refrigerant circuit is filled with compatible refrigerating machine oil, the turbulence of the jet remains, such as a position where the value of (L / d) is less than 20 and greater than 0 from the inner surface 50 of the header 47 or 48. Even if the center 45 or 46 of the outlet of the heat transfer tube 43 is installed at a certain position, the disproportionation reaction of the liquid refrigerant or the two-phase refrigerant due to the collision with the inner surface 50 hardly occurs.

For example, the inner diameter of the header 47 or 48 is 17.05 mm, the inner diameter of the heat transfer tube 43 is 7.44 mm, and the center 45 or 46 of the outlet of the heat transfer tube 43 is in contact with the inner surface of the header 47 or 48. Consider the case of connection. In this case, the distance L that is the inner diameter of the header 47 or 48 is d is the inner diameter of the heat transfer tube 43, and the value of (L / d) is 2.3. Therefore, a turbulence component that is considerably smaller than 20 to 30 and considerably larger remains.

Usually, in a building multi-air conditioner or the like, the condensation temperature, which is the temperature of the refrigerant in the condenser, is controlled by controlling the frequency of the compressor 10 and the rotational speed of a blower (not shown) attached to the heat source side heat exchanger 12. Control at about 50 ° C. Further, the expansion device 16 is controlled so that the degree of supercooling of the refrigerant at the outlet of the condenser is about 10 ° C. Therefore, if the condensation temperature is about 50 ° C., about 40 ° C. refrigerant flows out at the outlet of the condenser. Therefore, the refrigerant flowing into the second header 48 is in a saturated pressure state where the temperature is about 40 ° C. and the pressure is 50 ° C.

Considering the control performance (transient characteristics) in the expansion device 16, the refrigerant flowing into the second header 48 is in a state of a temperature between about 40-50 ° C. and a saturation pressure where the pressure is 50 ° C. . Therefore, if the solubility of the refrigerant in the refrigerating machine oil is high at these temperatures and pressures, the refrigerant disproportionation reaction hardly occurs. Practically, in the state where the refrigerant is at these temperatures and pressures, if the solubility of the refrigerant in the refrigerating machine oil is 50 wt% (weight percent) or more, many refrigerants are dissolved in the refrigerating machine oil, so disproportionation The reaction can be suppressed. That is, the value of (L / d) is less than 10 if the refrigerant flowing into the second header 48 has a solubility of 50 wt% (weight%) or more in the refrigeration oil and is dissolved in the refrigeration oil. Even when the refrigerant is ejected from such a relatively close position and collides with the inner surface 50 of the second header 48, the disproportionation reaction hardly occurs.

Here, the case where the refrigerant flowing into the second header 48 is a liquid refrigerant has been described as an example. However, when the amount of refrigerant filled in the refrigerant circuit is small, for example, a two-phase refrigerant having a dryness greater than 0 and less than or equal to 0.2 may flow into the second header 48. Even in this case, the same effect is obtained.

The refrigerant disproportionation reaction is likely to occur when the distance between adjacent substances such as liquid refrigerant and two-phase refrigerant is very close. Here, the case where the heat exchanger 12 or 15 acts as a condenser and the liquid refrigerant or the two-phase refrigerant flows into the second header 48 installed on the outlet side thereof has been described. In the heating operation, when the heat source side heat exchanger 12 acts as an evaporator, the two-phase refrigerant flows out from the heat transfer tube 43 and the two-phase refrigerant flows into the first header 47. Even in such a case, the disproportionation reaction of the refrigerant is likely to occur. Therefore, if the structure of the first header 47 and the heat transfer tube 43 is the same as the structure of the second header 48 and the heat transfer tube 43 described above, the disproportionation reaction can be made difficult to occur. Even when the load side heat exchanger 15 acts as an evaporator during the cooling operation, the two-phase refrigerant may flow out from the load side heat exchanger 15 to the first header 47. In this case as well, the same structure as the heat source side heat exchanger 12 may be used.

In general, in a building multi-air conditioner, for example, the driving frequency of the compressor 10 and the rotational speed of a blower (not shown) attached to the heat source side heat exchanger 12 are controlled to adjust the refrigerant in the evaporator. The evaporation temperature, which is the temperature, is controlled to about 0 ° C. Further, for example, the expansion device 16 is controlled so that the degree of superheat of the refrigerant at the outlet of the evaporator is about 0 to 5 ° C. Therefore, the refrigerant flowing into the first header 47 from the heat transfer tube 43 is in a saturated pressure state where the temperature is about 0 ° C. and the pressure is about 0 ° C. In this state, if the solubility of the refrigerant in the refrigerating machine oil is 50 wt% (weight%) or more, a large amount of refrigerant dissolves in the refrigerating machine oil, so that the disproportionation reaction can be made difficult to occur. Therefore, if the refrigerant flowing into the first header 47 has a solubility of 50 wt% (weight%) or more in the refrigeration oil and is dissolved in the refrigeration oil, the value of (L / d) is less than 10. Even when the refrigerant is ejected from such a relatively close position and collides with the inner surface 50 of the first header 47, the disproportionation reaction hardly occurs.

In this case, a two-phase refrigerant having a dryness of 0.8 or more and 0.99 or less flows into the first header 47, for example.

Here, in FIG. 7, the center 45 or 46 of the outlet of the heat transfer tube 43 is illustrated as if it is oriented in the normal direction of the inner surface 50 of the header 47 or 48, but the direction is not limited thereto. The outlet of the heat transfer tube 43 may be connected to the inner surface 50 of the header 47 or 48 in an inclined manner, and has the same effect.

Further, the shape of the outlet of the heat transfer tube 43 is not particularly limited, and may be any shape. Although shown here as a circular tube, the outlet of the heat transfer tube 43 may have a long hole shape formed by cutting obliquely with respect to the tube axis of the heat transfer tube 43, or other shapes may be used. Have the same effect. The equivalent diameter of the heat transfer tube 43 at this time is the inner diameter d.

Further, as described above, a hole is formed in the side surface of the header 47 or 48 and the heat transfer tube 43 is inserted, and the header 47 or 48 and the heat transfer tube 43 are fixed by brazing or the like. At this time, the center 45 or 46 of the outlet of the heat transfer tube 43 is often installed so as to protrude to the inner side of the position in contact with the inner surface of the header 47 or 48, and the amount of protrusion is 1 of the inner diameter of the header 47 or 48 / 3 or less in many cases. That is, the distance L is often smaller than the inner diameter of the header 47 or 48 and larger than 2/3 of the inner diameter of the header 47 or 48.

Here, in the heat exchanger 12 or 15 of FIG. 6, the path is divided into four, and the four heat transfer tubes 43 are connected to the header 47 or 48, but the number of the heat transfer tubes 43 is four. It is not limited to books.

FIG. 8 is a schematic diagram of another configuration of the heat exchanger of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. The heat exchanger 12 or 15 shown in FIG. 8 is configured to include a plurality of headers on the refrigerant inflow side and the refrigerant outflow side, respectively. Specifically, one end of the heat exchanger 12 or 15 has two first headers 47a and a first header 47b. The first connection pipe 41 is the same number (two in this case) of branch pipes as the number of headers. One of the branched pipes is connected to the first header 47a, and the other pipe is connected to the first header 47b. The first header 47a and the first header 47b are connected to the two heat transfer tubes 43, respectively.

The other end of the heat exchanger 12 or 15 also has two second headers 48a and second headers 48b. Further, the second connection pipe 42 is branched into two as many as the number of headers, one pipe is connected to the second header 48a, and the other pipe is connected to the second header 48b. The second header 48 a and the second header 48 b are connected to the two heat transfer tubes 43, respectively.

8, the connection pipe 41 or 42 is a branch pipe, and a heat exchanger structure connected to a plurality of (here, two) headers 47 or 48 has the same effect.

FIG. 9 is a schematic diagram of another configuration of the heat exchanger of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. The heat exchanger 12 or 15 in FIG. 9 is a so-called 1-2-pass heat exchanger in which the number of passes (number of channels) changes in the middle of the channel. In FIG. 9, the first connection pipe 41 is connected to the first header 47. The first header 47 is branched into six paths, and the number of paths is halved by joining two paths along the way. The second connection pipe 42 is connected to the second header 48, and the second header 48 is connected to the three heat transfer pipes 43. For this reason, the number of heat transfer tubes 43 connected to the first connection pipe 41 via the first header 47 is six, and the number of heat transfer tubes 43 connected to the second connection pipe 42 via the second header 48 is It becomes three.

As in the above configuration, the same effect can be obtained even in a heat exchanger structure in which the number of heat transfer tubes 43 connected to the first header 47 and the number of heat transfer tubes 43 connected to the second header 48 are different. .
Here, the configuration of the 1-2 path, the number of pipes, and the like are not limited thereto.

FIG. 10 is a schematic diagram of another heat transfer tube used in the heat exchanger of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. So far, the description has been made on the assumption that the heat transfer tube 43 is a circular tube. However, the shape of the heat transfer tube 43 is not limited to a circular tube. For example, FIG. 10 shows a flat tube having a flat channel structure in which the inside is divided into a plurality of (here, four) channels (microchannels) 49. In the case where such a flat tube is used for the heat transfer tube 43, the cross-sectional areas of the respective flow paths 49 inside one heat transfer tube 43 are summed up in considering the above-described configuration in which disproportionation reaction hardly occurs. The total sectional area is treated as the inner sectional area of one heat transfer tube 43. A specific example will be described below.

Here, as shown in FIG. 10, a case is considered in which the heat exchanger 12 or 15 of FIG. 6 is configured by a heat transfer tube 43 that is internally divided into four flow paths 49. In the heat exchanger 12 or 15 of FIG. 6, the four heat transfer tubes 43 are connected to the first connection pipe 41 via the first header 47, and the four heat transfer tubes 43 are connected to the first header pipe 48 via the second header 48. 2 connected to the connecting pipe 42. Therefore, when the inner cross-sectional areas of all the flow paths 49 in the heat transfer tube 43 are the same, the number of the flow paths 49 in one heat transfer pipe 43 (here, four), the inner cross-sectional area of the flow paths 49, and The value multiplied by is taken as the total inner cross-sectional area. And the value converted into an equivalent diameter based on the total inner cross-sectional area is treated as the inner diameter d. And the heat exchanger 12 or 15 (refrigeration cycle apparatus) with which disproportionation reaction hardly occurs can be comprised by making the relationship between the distance L and the internal diameter d into the same thing as the description mentioned above.

Here, the case where the inner cross-sectional areas of all the flow paths 49 in the heat transfer tube 43 are the same has been described as an example, but the present invention is not limited to this, and the cross-sectional areas of the inner cross-sectional areas of some of the flow paths 49 are May be different. For example, in FIG. 10, among the four flow paths 49, the inner cross-sectional areas of the two flow paths 49 at both ends may be different from the inner cross-sectional areas of the other flow paths 49. Further, the number of the flow paths 49 of the heat transfer tubes 43 is not limited to four.

In addition, the heat transfer tube 43 has a flat tube shape, and when the heat transfer tube 43 is connected to the header 47 or 48, a flat tube shape hole is formed in the header 47 or 48 and the heat transfer tube 43 is formed in the header 47 or 48. You may connect directly. Further, a circular hole may be formed in the header 47 or 48, and the header 47 or 48 may be connected to the header 47 or 48 via a joint that is deformed from a flat tube shape to a circular tube shape.

[Extended piping 4]
As described above, the refrigeration cycle apparatus 100 according to the present embodiment has several operation modes. In these operation modes, the refrigerant flows through the extension pipe 4 that connects the outdoor unit 1 and the indoor unit 2.

Here, the high pressure detection device 37 and the low pressure detection device 38 are installed to control the refrigeration cycle high pressure and low pressure to target values, but may be a temperature detection device that detects a saturation temperature.

Moreover, although the 1st refrigerant | coolant flow path switching device 11 was shown as if it were a four-way valve, it is not restricted to this, It uses the two-way flow path switching valve and the three-way flow path switching valve similarly, You may comprise so that a refrigerant | coolant may flow.

In general, a heat blower is attached to the heat source side heat exchanger 12 and the load side heat exchangers 15a to 15d, and in many cases, condensation or evaporation is promoted by air blowing, but it is not limited to this. . For example, as the load side heat exchangers 15a to 15d, a panel heater using radiation can be used, and as the heat source side heat exchanger 12, a water-cooled type that moves heat by water or antifreeze. Things can also be used. Any heat exchanger that can dissipate or absorb heat can be used.

In addition, the heat source side heat exchanger 12 or the load side heat exchangers 15a to 15d have fins 44 in order to improve the heat transfer performance, but sufficient heat transfer performance can be obtained by using only the heat transfer tube 43. May not have the fins 44.

In addition, here, the case where there are four load-side heat exchangers 15a to 15d has been described as an example, but any number may be connected. Further, a plurality of outdoor units 1 may be connected to constitute one refrigeration cycle.

In the present embodiment, the cooling / heating switching type refrigeration cycle apparatus 100 in which the indoor unit 2 performs only the cooling operation or the heating operation has been described as an example. However, the present invention is not limited to this. Absent. For example, the indoor unit 2 can arbitrarily select one of a cooling operation and a heating operation, and the entire system can perform a mixed operation of the indoor unit 2 that performs the cooling operation and the indoor unit 2 that performs the heating operation. The present invention can also be applied to a refrigeration cycle apparatus and has the same effect.

It can also be applied to air conditioners such as room air conditioners, to which only one indoor unit 2 can be connected, refrigeration equipment to connect a showcase and a unit cooler, etc., constituting a refrigerant circuit and using a refrigeration cycle If it is a refrigeration cycle device that supplies heat, the same effect is obtained.

Further, although the case where the first header 47 and the second header 48 are connected to both ends of the heat source side heat exchanger 12 or the load side heat exchangers 15a to 15d has been described as an example, the present invention is not limited to this. For example, a refrigerant distributor and a capillary tube are connected to one end of the heat source side heat exchanger 12 or the load side heat exchangers 15a to 15d, and the other end of the heat source side heat exchanger 12 or the load side heat exchangers 15a to 15d. You may comprise so that a header may be connected to. Further, regarding the distribution of the refrigerant flowing into the heat source side heat exchanger 12 or the load side heat exchangers 15a to 15d, any other configuration may be used.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to the drawings. In the following, the second embodiment will be described focusing on the differences from the first embodiment. Note that the modification applied in the configuration part of the first embodiment is also applied to the same configuration part of the second embodiment.

FIG. 11 is a circuit configuration diagram of the refrigeration cycle apparatus according to Embodiment 2 of the present invention. A refrigeration cycle apparatus 100 shown in FIG. 11 includes a refrigerant circulation circuit A in which an outdoor unit 1 and a heat medium relay unit 3 that is a relay unit are connected by an extension pipe 4 to circulate refrigerant. In addition, the refrigeration cycle apparatus 100 includes a heat medium circulation circuit B in which the heat medium converter 3 and the indoor unit 2 are connected by a pipe (heat medium pipe) 5 and a heat medium such as water or brine circulates. . The heat medium relay unit 3 includes a load side heat exchanger 15a and a load side heat exchanger 15b that perform heat exchange between the refrigerant circulating in the refrigerant circuit A and the heat medium circulating in the heat medium circuit B.

The heat medium relay unit 3 is located separately from the outdoor unit 1 and the indoor unit 2, for example, a ceiling that is inside the building 9 but separate from the indoor space 7 as shown in FIG. 1. It is installed in a space such as the back (hereinafter simply referred to as space 8). The heat medium relay 3 can also be installed in a common space where there is an elevator or the like.

[Type of refrigerant, heat exchanger (12 or 15)]
In this refrigeration cycle apparatus 100, the same refrigerant as in the first embodiment can be used, and the same effect can be obtained. Further, the header 47 or 48 described in the first embodiment is used as the heat source side heat exchanger 12.

The operation mode executed by the refrigeration cycle apparatus 100 includes a cooling only operation mode in which all of the driven indoor units 2 execute a cooling operation and a heating operation in which all of the driven indoor units 2 execute a heating operation. There is an operation mode. Further, there are a cooling main operation mode executed when the cooling load is larger, and a heating main operation mode executed when the heating load is larger.

[Cooling operation mode]
In the cooling only operation mode, the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11 and dissipates heat to the surrounding air. It condenses and becomes high-pressure liquid refrigerant and flows out of the outdoor unit 1 through the check valve 13a. Then, it flows into the heat medium relay unit 3 through the extension pipe 4. The refrigerant flowing into the heat medium relay unit 3 passes through the opening / closing device 17a, expands in the expansion device 16a and the expansion device 16b, and becomes a low-temperature and low-pressure two-phase refrigerant. The two-phase refrigerant flows into each of the load side heat exchanger 15a and the load side heat exchanger 15b acting as an evaporator, absorbs heat from the heat medium circulating in the heat medium circuit B, and becomes a low-temperature and low-pressure gas refrigerant. . The gas refrigerant flows out of the heat medium relay unit 3 through the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b. Then, it flows into the outdoor unit 1 again through the extension pipe 4. The refrigerant that has flowed into the outdoor unit 1 passes through the check valve 13d, and is sucked into the compressor 10 again via the first refrigerant flow switching device 11 and the accumulator 19.

In the heat medium circulation circuit B, the heat medium is cooled by the refrigerant in both the load side heat exchanger 15a and the load side heat exchanger 15b. The cooled heat medium flows through the pipe 5 by the pump 21a and the pump 21b. The heat medium flowing into the use side heat exchangers 26a to 26d through the second heat medium flow switching devices 23a to 23d absorbs heat from the indoor air. The indoor air is cooled to cool the indoor space 7. The refrigerant that has flowed out of the use side heat exchangers 26a to 26d flows into the heat medium flow control devices 25a to 25d, passes through the first heat medium flow switching devices 22a to 22d, and passes through the load side heat exchanger 15a and the load side. It flows into the heat exchanger 15b, is cooled, and is sucked into the pump 21a and the pump 21b again. Note that the heat medium flow control devices 25a to 25d corresponding to the use side heat exchangers 26a to 26d without heat load are fully closed. Further, the heat medium flow control devices 25a to 25d corresponding to the use side heat exchangers 26a to 26d having the heat load adjust the opening degree to adjust the heat load in the use side heat exchangers 26a to 26d.

[Heating operation mode]
In the heating only operation mode, the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows out of the outdoor unit 1 through the first refrigerant flow switching device 11 and the first connection pipe 4a and the check valve 13b. To do. Then, it flows into the heat medium relay unit 3 through the extension pipe 4. The refrigerant flowing into the heat medium relay unit 3 flows into the load side heat exchanger 15a and the load side heat exchanger 15b through the second refrigerant flow switching device 18a and the second refrigerant flow switching device 18b, respectively. The heat is radiated to the heat medium circulating in the heat medium circuit B, and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant expands in the expansion device 16a and the expansion device 16b to become a low-temperature and low-pressure two-phase refrigerant, and flows out of the heat medium relay unit 3 through the opening / closing device 17b. Then, it flows into the outdoor unit 1 again through the extension pipe 4. The refrigerant flowing into the outdoor unit 1 passes through the second connection pipe 4b and the check valve 13c, flows into the heat source side heat exchanger 12 acting as an evaporator, absorbs heat from the surrounding air, and is a low-temperature and low-pressure gas refrigerant. It becomes. The gas refrigerant is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19. Note that the operation of the heat medium in the heat medium circuit B is the same as in the cooling only operation mode. In the heating only operation mode, in the load-side heat exchanger 15a and the load-side heat exchanger 15b, the heat medium is heated by the refrigerant, and is radiated to the indoor air in the use-side heat exchanger 26a and the use-side heat exchanger 26b. The indoor space 7 is heated.

[Cooling operation mode]
In the cooling main operation mode, the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the first refrigerant flow switching device 11 and radiates and condenses to the surrounding air. Then, it becomes a two-phase refrigerant and flows out of the outdoor unit 1 through the check valve 13a. Then, it flows into the heat medium relay unit 3 through the extension pipe 4. The refrigerant flowing into the heat medium relay unit 3 flows into the load-side heat exchanger 15b acting as a condenser through the second refrigerant flow switching device 18b, and dissipates heat to the heat medium circulating in the heat medium circuit B. And high pressure liquid refrigerant. The high-pressure liquid refrigerant expands in the expansion device 16b and becomes a low-temperature and low-pressure two-phase refrigerant. The two-phase refrigerant flows into the load-side heat exchanger 15a acting as an evaporator through the expansion device 16a, absorbs heat from the heat medium circulating in the heat medium circuit B, and becomes a low-pressure gas refrigerant. It flows out of the heat medium relay unit 3 through the path switching device 18a. Then, it flows into the outdoor unit 1 again through the extension pipe 4. The refrigerant that has flowed into the outdoor unit 1 passes through the check valve 13d, and is sucked into the compressor 10 again via the first refrigerant flow switching device 11 and the accumulator 19.

In the heat medium circulation circuit B, the heat of the refrigerant is transmitted to the heat medium by the load side heat exchanger 15b. The heated heat medium flows in the pipe 5 by the pump 21b. The heat medium that has flowed into the use side heat exchangers 26a to 26d for which heating is requested by operating the first heat medium flow switching devices 22a to 22d and the second heat medium flow switching devices 23a to 23d radiates heat to the indoor air. To do. The indoor air is heated to heat the indoor space 7. On the other hand, the cold heat of the refrigerant is transmitted to the heat medium in the load side heat exchanger 15a. The cooled heat medium flows through the pipe 5 by the pump 21a. The heat medium that has flowed into the use side heat exchangers 26a to 26d for which cooling is requested by operating the first heat medium flow switching devices 22a to 22d and the second heat medium flow switching devices 23a to 23d absorbs heat from the indoor air. To do. The indoor air is cooled to cool the indoor space 7. Note that the heat medium flow control devices 25a to 25d corresponding to the use side heat exchangers 26a to 26d without heat load are fully closed. Further, the heat medium flow control devices 25a to 25d corresponding to the use side heat exchangers 26a to 26d having the heat load adjust the opening degree to adjust the heat load in the use side heat exchangers 26a to 26d.

[Heating main operation mode]
In the heating main operation mode, the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 passes through the first refrigerant flow switching device 11, passes through the first connection pipe 4 a and the check valve 13 b, and then the outdoor unit 1. Spill from. Then, it flows into the heat medium relay unit 3 through the extension pipe 4. The refrigerant flowing into the heat medium relay unit 3 flows into the load-side heat exchanger 15b acting as a condenser through the second refrigerant flow switching device 18b, and dissipates heat to the heat medium circulating in the heat medium circuit B. And high pressure liquid refrigerant. The high-pressure liquid refrigerant expands in the expansion device 16b and becomes a low-temperature and low-pressure two-phase refrigerant. The two-phase refrigerant flows into the load-side heat exchanger 15a acting as an evaporator via the expansion device 16a, absorbs heat from the heat medium circulating in the heat medium circuit B, and passes through the second refrigerant flow switching device 18a. And flows out of the heat medium relay unit 3. Then, it flows into the outdoor unit 1 again through the extension pipe 4. The refrigerant flowing into the outdoor unit 1 passes through the second connection pipe 4b and the check valve 13c, flows into the heat source side heat exchanger 12 acting as an evaporator, absorbs heat from the surrounding air, and is a low-temperature and low-pressure gas. Becomes a refrigerant. The gas refrigerant is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19. The operation of the heat medium in the heat medium circuit B, the first heat medium flow switching devices 22a to 22d, the second heat medium flow switching devices 23a to 23d, the heat medium flow control devices 25a to 25d, and the use side The operations of the heat exchangers 26a to 26d are the same as those in the cooling main operation mode.

[Extended piping 4 and piping 5]
In each operation mode in the present embodiment, the refrigerant flows through the extension pipe 4 that connects the outdoor unit 1 and the heat medium converter 3, and the pipe 5 that connects the heat medium converter 3 and the indoor unit 2 contains water. Heat medium such as antifreeze liquid is flowing.

When the heating load and the cooling load are mixed in the use side heat exchanger 26, the first heat medium flow switching device 22 corresponding to the use side heat exchanger 26 performing the heating operation and The second heat medium flow switching device 23 is switched to a flow path connected to the load side heat exchanger 15b for heating. Further, the first heat medium flow switching device 22 and the second heat medium flow switching device 23 corresponding to the use side heat exchanger 26 performing the cooling operation are connected to the cooling load side heat exchanger 15a. Switch to the flow path. For this reason, in each indoor unit 2, heating operation and cooling operation can be performed freely.

Here, the first heat medium flow switching device 22 and the second heat medium flow switching device 23 can switch a three-way flow path such as a three-way valve, and can open and close a two-way flow path such as an on-off valve. What is necessary is just to be able to switch a flow path, such as combining two. In addition, the first heat medium can be obtained by combining two things such as a stepping motor drive type mixing valve that can change the flow rate of the three-way flow path and two things that can change the flow rate of the two-way flow path such as an electronic expansion valve. The flow path switching device 22 and the second heat medium flow path switching device 23 may be used. Furthermore, the heat medium flow control device 25 may be installed as a control valve having a three-way flow path with a bypass pipe that bypasses the use-side heat exchanger 26 other than the two-way valve. Further, the heat medium flow control device 25 may be a stepping motor drive type that can control the flow rate flowing through the flow path, and may be a two-way valve or a device in which one end of the three-way valve is closed. Further, as the heat medium flow control device 25, a device that opens and closes a two-way flow path such as an open / close valve may be used, and the average flow rate may be controlled by repeating ON / OFF.

Further, the first refrigerant flow switching device 11 and the second refrigerant flow switching device 18 are shown as if they were four-way valves. However, the present invention is not limited to this, and a two-way flow switching valve or a three-way flow switching is possible. A plurality of valves may be used so that the refrigerant flows in the same manner.

Further, it goes without saying that the same is true even when only one use-side heat exchanger 26 and one heat medium flow control device 25 are connected, and the load-side heat exchanger 15 and the expansion device 16 are the same. Of course, there is no problem even if multiple moving objects are installed. Furthermore, although the case where the heat medium flow control device 25 is built in the heat medium converter 3 has been described as an example, the heat medium flow control device 25 is not limited thereto, and may be built in the indoor unit 2. 3 and the indoor unit 2 may be configured separately.

Further, if the first heat medium flow switching device 22 and / or the second heat medium flow switching device 23 is configured to have a function of adjusting the flow rate of the heat medium, the heat medium flow control device 25 may not be provided. Also good.

As the heat medium, for example, brine (antifreeze), water, a mixture of brine and water, a mixture of water and an additive having a high anticorrosive effect, or the like can be used. Therefore, in the refrigeration cycle apparatus 100, even if the heat medium leaks into the indoor space 7 through the indoor unit 2, a highly safe heat medium is used, which contributes to an improvement in safety. Become.

In general, the heat source side heat exchanger 12 and the use side heat exchangers 26a to 26d are provided with a blower, and in many cases, condensation or evaporation is promoted by blowing, but this is not restrictive. . For example, as the use side heat exchangers 26a to 26d, a panel heater using radiation can be used. Moreover, as the heat source side heat exchanger 12, a water-cooled type that moves heat by water or antifreeze can also be used. Any structure that can dissipate or absorb heat can be used.

In addition, here, the case where there are four use-side heat exchangers 26a to 26d has been described as an example, but any number may be connected. Further, a plurality of outdoor units 1 may be connected to constitute one refrigeration cycle.

Further, the case where there are two load- side heat exchangers 15a and 15b has been described as an example, but of course, the present invention is not limited to this, and any number of configurations can be used as long as the heat medium can be cooled or / and heated. May be installed.

Further, a plate-type heat exchanger is generally used as the load-side heat exchanger 15. However, the load-side heat exchanger 15 is not limited to a plate type, but can be any type that can exchange heat between the refrigerant and the heat medium. It may be a thing.

Also, the number of pumps 21a and 21b is not limited to one, and a plurality of small capacity pumps may be arranged in parallel.

Further, the refrigeration cycle apparatus of the present embodiment accommodates the compressor 10, the four-way valve (first refrigerant flow switching device) 11, and the heat source side heat exchanger 12 in the outdoor unit 1, and air and refrigerant in the air-conditioning target space Are used in the indoor unit 2, and the load-side heat exchanger 15 and the expansion device 16 are accommodated in the heat medium converter 3. Further, the outdoor unit 1 and the heat medium converter 3 are connected by an extension pipe 4 to circulate the refrigerant, and the indoor unit 2 and the heat medium converter 3 are connected by a set of two pipes 5 each. Thus, the heat medium is circulated, and the load-side heat exchanger 15 exchanges heat between the refrigerant and the heat medium. In such an apparatus, in the present embodiment, the explanation has been given by taking as an example a system capable of mixed operation of the indoor unit 2 that performs the cooling operation and the indoor unit 2 that performs the heating operation. However, the present invention is not limited to this. . For example, the outdoor unit 1 and the heat medium relay unit 3 described in the first embodiment can be combined and applied to a system that performs only a cooling operation or a heating operation in the indoor unit 2 and has the same effect.

Embodiment 3 FIG.
As shown in the first embodiment and the second embodiment, it is common to use a four-way valve as the first refrigerant flow switching device 11, but this is not a limitation. For example, a plurality of two-way flow switching valves and three-way flow switching valves may be used so that the refrigerant flows in the same manner as when a four-way valve is used.

In the first and second embodiments, the case where the accumulator 19 for storing the excess refrigerant is provided in the refrigerant circuit has been described. However, the present invention is not limited to this. For example, in the case where the extension pipe 4 is short, the number of indoor units 2 is one, etc., there is no problem even if the accumulator 19 is not provided because the surplus refrigerant is small in the refrigerant circuit.

1 Heat source unit (outdoor unit), 2, 2a, 2b, 2c, 2d indoor unit, 3 heat medium converter (relay unit), 4 extension pipe (refrigerant pipe), 4a first connection pipe, 4b second connection pipe, 5 piping (heat medium piping), 6 outdoor space, 7 indoor space, 8 outdoor space such as the back of the ceiling and indoor space, 9 building, 10 compressor, 11 1st refrigerant flow switching device (Four-way valve), 12 heat source side heat exchanger (first heat exchanger), 13a, 13b, 13c, 13d check valve, 15, 15a, 15b, 15c, 15d load side heat exchanger (second heat Exchanger, 16, 16a, 16b, 16c, 16d throttle device, 17a, 17b switchgear, 18, 18a, 18b second refrigerant flow switching device, 19 accumulator, 21a, 21b pump, 22, 22a, 22b, 2 c, 22d First heat medium flow switching device, 23, 23a, 23b, 23c, 23d Second heat medium flow switching device, 25, 25a, 25b, 25c, 25d Heat medium flow control device, 26, 26a, 26b , 26c, 26d, use side heat exchanger, 27 load side heat exchanger liquid refrigerant temperature detection device, 28 load side heat exchanger gas refrigerant temperature detection device, 37 high pressure detection device, 38 low pressure detection device, 41 first connecting pipe, 42, second connection pipe, 43 heat transfer pipe, 44 fin, 45, center (outlet at one end of heat transfer pipe 43), 46, center (outlet at the other end of heat transfer pipe 43), 47, 47a, 47b, first header, 48 48a, 48b, second header, 49 flow path, 50 inner surface, 60 control device, 100 refrigeration cycle device, A refrigerant circulation circuit, B heat medium circulation circuit.

Claims (14)

1. A single refrigerant or disproportionation reaction composed of a substance having the property of causing a disproportionation reaction by connecting the compressor, the first heat exchanger, the expansion device, and the second heat exchanger with refrigerant piping. A refrigerant circuit is formed by filling a mixed refrigerant containing a substance having a property of causing a refrigerant and refrigerating machine oil compatible with the refrigerant,
   At least one of the first heat exchanger and the second heat exchanger is:
   A plurality of heat transfer tubes through which the refrigerant flows, and a header through which the end of the heat transfer tube on the refrigerant outlet side is inserted and the refrigerant passes through the tubes;
   The inner diameter of the header is larger than the inner diameter of the heat transfer tube, and the end portion on the refrigerant outlet side of the heat transfer tube is installed to face the inner wall surface of the header,
   The distance from the center of the end portion on the refrigerant outlet side of the heat transfer tube to the pipe inner wall surface of the header corresponding to the center is L, and the inner diameter or the equivalent diameter corresponding to the inner diameter at the end portion on the refrigerant outlet side of the heat transfer tube A refrigeration cycle apparatus in which the refrigerant outlet side end of the heat transfer tube is located at a position where the value of L / d is less than 20 and greater than 0 when the inner diameter is d.
2. In a state where the temperature of the refrigerant is 50 ° C. and the pressure of the refrigerant is a saturation pressure of 50 ° C., the refrigerating machine oil having a solubility in the refrigerating machine oil of 50 weight percent or more is charged, and the L / The refrigeration cycle apparatus according to claim 1, wherein an outlet of the heat transfer tube is installed at a position where the value of d is less than 10 and more than 0.
3. In the state where the temperature of the refrigerant is 40 ° C. and the pressure of the refrigerant is a saturation pressure of 50 ° C., the refrigerating machine oil having a solubility in the refrigerating machine oil of 50 weight percent or more is charged, and the L / The refrigeration cycle apparatus according to claim 1 or 2, wherein an outlet of the heat transfer tube is installed at a position where the value of d is less than 10 and more than 0.
4. The operation for controlling circulation of the refrigerant is performed so that the refrigerant in a two-phase state having a dryness greater than 0 and less than or equal to 0.2 flows through the header. The refrigeration cycle apparatus described in 1.
5. The refrigerating machine oil is filled with a refrigerant having a solubility in the refrigerating machine oil of 50% by weight or more in a state where the temperature of the refrigerant is 0 ° C. and the pressure of the refrigerant is 0 ° C., and The refrigeration cycle apparatus according to claim 1, wherein an outlet of the heat transfer tube is installed at a position where the value of L / d is less than 10 and more than 0.
6. The refrigeration according to claim 1 or 5, wherein an operation for controlling circulation of the refrigerant is performed so that the two-phase refrigerant having a dryness of 0.8 or more and 0.99 or less flows in the header. Cycle equipment.
7. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the distance L is smaller than an inner diameter of the header and larger than 2/3 of an inner diameter of the header.
8. An outdoor unit that houses one of the first heat exchanger or the second heat exchanger, and an indoor unit that houses the other of the first heat exchanger or the second heat exchanger. The refrigeration cycle apparatus according to any one of claims 1 to 7.
9. An outdoor unit that houses one of the first heat exchanger or the second heat exchanger;
   An indoor unit that supplies heat to the load;
   A relay unit that accommodates the other of the first heat exchanger or the second heat exchanger and that can be installed at a position separated from the outdoor unit and the indoor unit. The refrigeration cycle apparatus according to any one of claims 1 to 8.
10. The heat exchanger serving as the first heat exchanger or the second heat exchanger housed in the relay machine exchanges heat between the refrigerant and a heat medium different from the refrigerant. Refrigeration cycle equipment.
11. The first heat exchanger or the second heat exchanger housed in the outdoor unit is a heat exchanger that exchanges heat between the refrigerant and the heat medium. The refrigeration cycle apparatus according to any one of 10.
12. 12. The apparatus according to claim 8, comprising one or a plurality of the outdoor units and one or a plurality of the indoor units, wherein each of the indoor units is configured to be able to supply the heat exchanged with the refrigerant to the load. The refrigeration cycle apparatus according to claim 1.
13. A refrigerant flow switching device for switching a flow path of the refrigerant, wherein one heat exchanger of the first heat exchanger and the second heat exchanger acts as a condenser, and the first heat exchanger And a first operation mode in which the other heat exchanger of the second heat exchanger acts as an evaporator, and one heat exchanger of the first heat exchanger and the second heat exchanger is evaporated. And a second operation mode in which the other heat exchanger of the first heat exchanger and the second heat exchanger acts as a condenser. The refrigeration cycle apparatus according to one item.
14. The refrigeration cycle apparatus according to any one of claims 1 to 13, wherein the substance causing the disproportionation reaction is 1,1,2-trifluoroethylene.

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