JP2017203571A - Refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration cycle device which can be installed easily at cheap price while enhancing reliability of the device.SOLUTION: A refrigeration cycle device at least includes: an outdoor unit 40 at least including a compressor 1 for compressing a refrigerant, and a heat source side heat exchanger 3 for heating or cooling the refrigerant; an indoor unit 20 at least including a use side heat exchanger 22 for heating or cooling the refrigerant; a receiver 6 having an internal space for separating the refrigerant into a liquid phase 61 and a gas phase 62; and an oxygen adsorbent 65 for adsorbing oxygen in the internal space. The indoor unit 20 and the outdoor unit 40 are constituted by including an oxygen adsorption device 91 which are constituted separately; and piping for connecting the indoor unit 20, the outdoor unit 40 and the oxygen adsorption container 91 and for allowing the refrigerant to circulate in a predetermined manner.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a refrigeration cycle apparatus using a refrigeration cycle, such as an air conditioner or a refrigerator.

  After installing a refrigeration cycle apparatus such as an air conditioner or a refrigerator, evacuation is performed using a vacuum pump or the like in order to remove air in the refrigeration cycle such as refrigerant piping. However, depending on the performance of the vacuum pump that performs evacuation, evacuation may not be performed sufficiently. In such a case, air remains in the refrigeration cycle, and the refrigerating machine oil can be oxidized and deteriorated by oxygen in the air, thereby generating an acid.

  In addition, a hydrofluoroolefin (HFO) refrigerant having a low global warming potential (GWP) has attracted attention as a refrigerant to be sealed in the refrigeration cycle. In the HFO refrigerant, a double bond is introduced between adjacent carbon atoms in order to realize a low GWP. Since this double bond is highly reactive, if oxygen remains in the refrigeration cycle, decomposition of the refrigerant is accelerated by the oxygen. Therefore, an acid such as hydrofluoric acid can be generated by such oxidative decomposition of the refrigerant.

  When acid is generated due to oxidative degradation of the refrigerating machine oil or oxidative decomposition of the refrigerant and the amount of acid in the refrigeration cycle increases, for example, in the sliding part of the compressor, not only mechanical wear but also chemical wear occurs, Wear is promoted. Moreover, when the material which comprises a refrigerating cycle contains copper, copper can elute with the generated acid. And the copper ion produced by the elution of copper can form copper plating, for example in the sliding part of a compressor. The acceleration of wear and the formation of copper plating as described above cause a significant decrease in the reliability of the compressor. Furthermore, the acid may corrode the parts where the fluid flow rate is high, for example, the valve portion of the expansion device by erosion / corrosion. When such corrosion occurs, the reliability of the refrigeration cycle is significantly reduced.

  Therefore, in order to increase the reliability of the refrigeration cycle apparatus, a technique for removing air (particularly oxygen) in the refrigeration cycle is desired. Patent Document 1 describes a refrigeration cycle in which a refrigerant containing a compound having a double bond is used, and an oxygen adsorbent is provided in the refrigeration cycle.

JP 2008-267680 A

  The influence of oxygen mixed in the refrigeration cycle becomes large when the amount of mixed air is large. The amount of air mixed into the refrigeration cycle is increased when the length of the connecting pipe connecting the heat source side unit (for example, an outdoor unit in an air conditioner) and the use side unit (for example, an indoor unit in an air conditioner) is long. This is a case where the internal volume of the refrigeration cycle apparatus is large, such as when there are many connected units on the use side. Therefore, it is particularly preferable to install an oxygen adsorbent in such a refrigeration cycle apparatus having a large internal volume to suppress the influence of oxygen.

  Further, when an oxygen adsorbent is installed in the refrigeration cycle apparatus, it is preferable that the oxygen adsorbent is installed in a place with as much oxygen as possible. Thereby, oxygen can be adsorbed effectively. Here, according to the study by the present inventors, since the flow of the refrigerant stagnates in the gas phase portion of the receiver provided in the refrigeration cycle apparatus, the air mixed in the refrigerant easily collects above the gas phase portion of the receiver. I understood it. Therefore, it can be said that the oxygen adsorbent is preferably installed so as to be able to adsorb oxygen accumulated above the receiver. Since the receiver is usually built in the heat source side unit, the oxygen adsorbent is built in the heat source side unit containing the receiver.

  However, when an oxygen adsorbent is built in the heat source side unit, even if the refrigeration cycle apparatus that does not require the use of the oxygen adsorbent, for example, when the connection pipe length is short and the number of connected units on the use side unit is small, oxygen Adsorbent will be loaded. Therefore, in such a refrigeration cycle apparatus, the cost of the oxygen adsorbent is increased. Further, for example, if the design change of the heat source side unit containing the oxygen adsorbent is made according to the length of the connection pipe, the number of connected use side units, etc., the installation of the refrigeration cycle apparatus becomes complicated.

  The present invention has been made in view of such problems, and the problem to be solved and used by the present invention is to provide a refrigeration cycle apparatus that can be installed easily and inexpensively while improving the reliability of the apparatus. is there.

  The present inventors have intensively studied to solve the above problems. As a result, the following knowledge was found and the present invention was completed. That is, the present invention includes at least a heat source side unit including at least a compressor that compresses a refrigerant, a heat source side heat exchanger that heats or cools the refrigerant, and at least a use side heat exchanger that cools or cools the refrigerant. At least a refrigerant container having an internal space that separates the refrigerant into a liquid phase and a gas phase, and an oxygen adsorbent that adsorbs oxygen in the internal space. An oxygen adsorbing unit configured separately from the unit, and a pipe that connects the heat source unit, the use side unit, and the oxygen adsorbing unit to flow the refrigerant in a predetermined manner. The present invention relates to a refrigeration cycle apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the refrigerating-cycle apparatus which can be installed easily and cheaply can be provided, improving the reliability of an apparatus.

It is a figure which shows the systematic diagram of the air conditioner of this embodiment. It is a figure which shows the systematic diagram of the refrigerator of this embodiment. It is a figure which shows another embodiment about the oxygen adsorption | suction apparatus with which the refrigeration cycle apparatus of this embodiment is equipped. It is a figure which shows the flow performed from installation to normal operation when installing the refrigerator of this embodiment. It is a table | surface which shows the opening / closing timing of the on-off valve with which the oxygen adsorption apparatus shown in FIG. 3 is equipped. It is a figure which shows another embodiment about the oxygen adsorption | suction apparatus with which the refrigerating-cycle apparatus of this embodiment is equipped. It is a figure which shows the modification about the receiver with which the refrigerating-cycle apparatus of this embodiment is equipped.

  Hereinafter, a form for carrying out the present invention (this embodiment) will be described with reference to the drawings as appropriate. In the drawings, the same members and devices are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 1 is a diagram illustrating a system diagram of an air conditioner 100 according to the present embodiment. The air conditioner 100 includes an indoor unit 20 installed in a room (not shown) to be air-conditioned, an outdoor unit 40 installed outside, a liquid side connection pipe 9 that connects these units and circulates a refrigerant, and a gas. The side connection piping 10 is provided. And between the indoor unit 20 and the outdoor unit 40, the refrigerant | coolant circulates through the liquid side connection piping 9 and the gas side connection piping 10, and the refrigerating cycle is formed. As will be described in detail later, an oxygen adsorption device 91 is attached to the refrigeration cycle, and the refrigerant circulates among the indoor unit 20, the outdoor unit 40, and the oxygen adsorption device 91. Therefore, the air conditioner 100 is an apparatus including a refrigeration cycle, that is, a refrigeration cycle apparatus.

  The indoor unit 20 includes an expansion device 21 (such as an expansion valve) and a use side heat exchanger 22 and a fan that blows air to the use side heat exchanger 22 (not shown). When the fan is driven to rotate, heat is exchanged in the use-side heat exchanger 22, and air conditioning of the room is performed. The outdoor unit 40 includes a compressor 1, a four-way valve 2, a heat source side heat exchanger 3, an expansion device 4 (an expansion valve or the like), a liquid pipe 5, a liquid pipe 7, a blocking valve 8, And an accumulator 12. The four-way valve 2 shown in FIG. 1 is shown facing the direction during cooling operation. Of these, the accumulator 12 separates gas refrigerant and liquid refrigerant and stores the refrigerant, and has a function of adjusting the amount of refrigerating machine oil supplied to the compressor 1.

  In the air conditioner 100, an oxygen adsorption device 91 that adsorbs and removes oxygen in the refrigeration cycle is provided separately from the indoor unit 20 and the outdoor unit 40. The oxygen adsorption device 91 is configured, for example, in a box shape and is provided outside the casing of the indoor unit 20 and the outdoor unit 40. In the air conditioner 100, the oxygen adsorption device 91 is attached to the outer surface of the outdoor unit 40. If the oxygen adsorption device 91 is no longer needed, the oxygen adsorption device 91 can be easily removed without disassembling the outdoor unit 40. Although not shown, an attachment portion to which the oxygen adsorption device 91 can be attached is provided on the outer surface of the outdoor unit 40.

  The oxygen adsorbing device 91 is in communication with the filling container 64 filled with the oxygen adsorbent 65, the filling container 64, and includes a liquid phase 61 containing a liquid refrigerant and a gas refrigerant in a part of the circulating refrigerant. A receiver 6 is provided which is separated into a gas phase 62 and stored. The receiver 6 is provided at a position where liquid refrigerant flows in a pipe connecting the compressor 1, the heat source side heat exchanger 3, the expansion device 4, and the use side heat exchanger 22. Specifically, the receiver 6 is connected to the liquid connection pipe 6. The filling container 64 is provided above the receiver 6 so as to be separated from the receiver 6 and communicated with the gas phase 62 via the connection pipe 63 above the receiver 6. The oxygen adsorbent 65 is fixed in the internal space of the filling container 64 while being sandwiched between punching metal and a metal mesh. The receiver 6 and the filling container 64 are accommodated in a storage box (not shown), and thereby an oxygen adsorption device 91 is configured.

  In the present embodiment, the oxygen adsorbent 65 includes iron powder (iron-based material) that can selectively adsorb only oxygen as described above, and, if necessary, inorganic salt or ore powder (vermulite). ), Activated carbon and the like. Specific examples of the oxygen adsorbent 65 include AGELESS (registered trademark, manufactured by Mitsubishi Gas Chemical Company), Secur (registered trademark, manufactured by Nisso Fine), and the like. Since the temperature of the receiver 6 increases only to about 50 ° C. at the maximum, the use of the iron-based oxygen adsorbent 65 suppresses the reaction between iron and the refrigerant. In addition, iron is oxidized and iron oxide produces | generates because oxygen adsorb | sucks to iron powder. By using such an iron-based material, even when a refrigerant having a molecular diameter similar to that of oxygen (described later, for example, R32) is used, only oxygen from the refrigerant is used. Can be selectively adsorbed and removed. And the adsorption and removal of oxygen in the refrigeration cycle can suppress the oxidative decomposition of the refrigerant and the refrigeration oil, and can improve the reliability of the air conditioner 100.

  Here, in the gas phase 62 of the receiver 6 to which the filling container 64 is attached, the ratio of non-condensable gas (including oxygen) to the refrigerant is higher than that in the refrigerant circulating in the refrigeration cycle. Specifically, according to the study by the present inventors, the volume ratio is, for example, about 3 times larger. This is because the refrigerant flow is stagnant in the gas phase 62 of the receiver 6. For this reason, the non-condensable gas having a density lower than that of the refrigerant moves above the gas phase 62 of the receiver 6, but as it goes above the gas phase 62, the liquid pipe 5 and the liquid connection pipe 9 that lead the refrigerant into and out of the receiver 6. It will move away from the connection port. The non-condensable gas existing above the gas phase 62 of the receiver 6 remains in the gas phase 62 without being discharged from the receiver 6. Accordingly, oxygen easily reaches the filling container 64 through the connection pipe 63 connected to the upper part of the receiver 6.

  Further, oxygen rises in the internal space of the receiver 6 (that is, the gas phase 62) due to the difference in specific gravity with the refrigerant or the like. Therefore, oxygen rises without interrupting the flow of the refrigerant, so that the filling container 64 is provided above the receiver 6 separately from the receiver 6 to cause excessive pressure loss in the flow of the refrigerant. There is no. Therefore, the air conditioner 100 and energy saving can be improved.

  Further, the filling container 64 is provided separately from the receiver 6 as described above, and these are connected by the connection pipe 63, so that the refrigerating machine oil of the compressor 1 circulating along with the refrigerant is filled with the filling container 64. 64 becomes difficult to reach. That is, since the specific gravity of refrigerating machine oil is usually larger than the specific gravity of oxygen or refrigerant, the vapor or mist of refrigerating machine oil rises and passes through the connecting pipe 63 unlike the oxygen or gas refrigerant. It is difficult to reach 64. And it is prevented that the iron powder inside the filling container 64 is covered with the refrigerating machine oil by making the refrigerating machine oil difficult to reach the filling container 64. Thereby, the surface area of the powder surface from which oxygen is adsorbed can be maintained in a wide state. For this reason, it is possible to prevent the oxygen adsorption performance from deteriorating and to sufficiently adsorb and remove oxygen mixed in the refrigerant.

  Although not shown, drive control of the air conditioner 100 is performed by a control device. Although not shown, this control device includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an I / F (interface), and the like. Composed. The control device is realized by executing a predetermined control program stored in the ROM by the CPU.

  The flow of the refrigerant in the air conditioner 100 shown in FIG. 1 will be described. When the air conditioner 100 is in cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged from the compressor 1 together with the refrigerating machine oil. The discharged gas refrigerant flows into the heat source side heat exchanger 3 through the four-way valve 2. The inflowing gas refrigerant is heat-exchanged in the heat source side heat exchanger 3 to be condensed and liquefied.

  The refrigerant (liquid refrigerant) condensed and liquefied in the heat source side heat exchanger 3 passes through the fully opened expansion device 4, liquid pipe 5, blocking valve 8 and receiver 6, passes through the liquid side connection pipe 9, and enters the indoor unit 20. Sent. The sent liquid refrigerant flows into the expansion device 21, where it is depressurized to a low pressure and becomes a low-pressure two-phase state. And the refrigerant | coolant which became the low voltage | pressure two phase state is evaporated by exchanging heat with utilization side media, such as air, by the utilization side heat exchanger 22, and turns into a gas refrigerant. Thereafter, the gas refrigerant passes through the gas side connection pipe 10, returns to the compressor 1 through the blocking valve 11, the four-way valve 2, and the accumulator 12. The returned refrigerant is discharged from the compressor 1 again. The refrigerant circulates by such a refrigerant flow, and a refrigeration cycle is formed.

  On the other hand, when the air conditioner 100 is operated for heating, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged from the compressor 1 together with the refrigerating machine oil. The discharged gas refrigerant flows into the use side heat exchanger 22 through the four-way valve 2, the blocking valve 11, and the gas side connection pipe 10. The inflowing gas refrigerant is heat-exchanged with a use side medium such as air in the use side heat exchanger 22 to be condensed and liquefied.

  The refrigerant (liquid refrigerant) condensed and liquefied in the use side heat exchanger 22 flows into the heat source side heat exchanger 3 through the liquid side connection pipe 9, the receiver 6, the blocking valve 8, the liquid pipe 5, and the expansion device 4. And the liquid refrigerant which flowed in is heat-exchanged with heat source media, such as air and water, in the heat source side heat exchanger 3, and is evaporated, and becomes a gas refrigerant. Thereafter, the gas refrigerant returns to the compressor 1 through the four-way valve 2 and the accumulator 12. The returned refrigerant is discharged from the compressor 1 again. The refrigerant circulates by such a refrigerant flow, and a refrigeration cycle is formed.

  In the air conditioner 100, a refrigerant containing hydrofluoroolefin (HFO) is used. More specifically, a mixed refrigerant of an HFC refrigerant such as R32 and an HFO refrigerant such as HFO-1234yf is used. By using such a refrigerant, it is possible to obtain a highly reliable air conditioner 100 by preventing decomposition of HFO refrigerant by oxygen as an effect of adsorbing and removing oxygen while preventing global warming. .

  In the air conditioner 100 shown in FIG. 1, the pipe for connecting the indoor unit 20 and the outdoor unit 40 is long, and from the viewpoint of sufficiently removing oxygen mixed in the refrigeration cycle, the oxygen adsorption container 91 connected to the refrigeration cycle includes It is attached to the outer surface of the outdoor unit 40. On the other hand, there may be a case where the piping connecting the indoor unit 20 and the outdoor unit 40 is short, the amount of oxygen mixed in the refrigeration cycle is small, and the influence of oxygen can be ignored. Therefore, in such a case, the oxygen adsorption device 91 can be prevented from being attached.

  Accordingly, the oxygen adsorption device 91 can be appropriately attached according to the length of the pipe. That is, since the oxygen adsorbing device 91 can be externally attached, a large design change of the outdoor unit 40 and the like accompanying the attachment of the oxygen adsorbing device 91 is unnecessary, and installation and the like are easy. Moreover, since it is only necessary to connect to the pipe and attach it only when it is desired to remove oxygen, the equipment cost of the oxygen adsorbent 65 and the like can be reduced.

  Further, in the air conditioner 100, the refrigerant filling amount is set so that the refrigerant state of the receiver 6 includes the liquid phase 61 and the gas phase 62. Thereby, the state of the refrigerant | coolant of the liquid connection piping 9 is a saturated state both at the time of air_conditionaing | cooling operation and heating operation. Therefore, the state of the refrigerant in the receiver 6 is in a gas-liquid equilibrium state. Therefore, the gas phase 62 is formed inside the receiver 6 in both the cooling operation and the heating operation, and oxygen exists in the gas phase 62 in a high concentration as described above. Thus, oxygen can be efficiently adsorbed by the oxygen adsorbent 65 inside the filling container 64 communicating with the gas phase 62.

  The amount of refrigerant sealed in the air conditioner 100 is such that the degree of refrigerant subcooling can be secured at the outlet of the heat source side heat exchanger 3 during cooling operation and at the outlet of the use side heat exchanger 22 during heating operation. In this case, the refrigerant flowing through the liquid pipe 5 and the liquid connection pipe 9 is in a supercooled state. Therefore, in this case, the gas phase 62 does not exist in the receiver 6. Therefore, in such a case, the opening degree of the expansion device 4 arranged at the outlet of the heat source side heat exchanger 3 during the cooling operation is reduced, and the opening degree of the expansion device 21 arranged at the outlet of the use side heat exchanger 22 is reduced during the heating operation. It is preferable. By doing in this way, the circulating refrigerant can be decompressed and the state of the refrigerant flowing through the liquid pipe 5 and the liquid connection pipe 9 can be adjusted to a saturated state. Thus, oxygen can be efficiently adsorbed by the oxygen adsorbent 65 so that the gas phase 62 is formed inside the receiver 6.

  FIG. 2 is a diagram showing a system diagram of the refrigerator 200 of the present embodiment. The refrigerator 200 is an example of a refrigeration cycle apparatus, similar to the air conditioner 100 described above. However, in the refrigerator 200, unlike the air conditioner 100, only the cooling operation is performed without performing the heating operation. The refrigerator 200 has basically the same configuration as the air conditioner 100 described above, but in the refrigerator 200, for example, a refrigerant that circulates in order to enhance the cooling capacity in the freezing unit 23 installed in a showcase or the like. About supercooling has been done. With respect to this point, the apparatus configuration provided in the refrigerator 200 will be described while explaining the flow of the refrigerant in the refrigerator 200 with reference to FIG.

  The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged from the compressor 1 together with the refrigerating machine oil. The discharged gas refrigerant flows into the heat source side heat exchanger 3, where it is exchanged for heat to be condensed and liquefied to become liquid refrigerant. The heat source side heat exchanger 3 is provided with an air-cooled supercooling heat exchanger 33 that brings the liquid refrigerant into a supercooled state. Therefore, the liquid refrigerant is brought into a supercooled state by the air-cooled supercooling heat exchanger 33. The supercooled liquid refrigerant passes through the liquid pipe 5, the receiver 90, and the liquid pipe 7 and is sent to the main pipe 81 of the supercooling heat exchanger 80. Incidentally, the receiver 90 is provided at a position where the liquid refrigerant flows, similarly to the receiver 6 described above, and includes a liquid phase containing the liquid refrigerant and a gas refrigerant in a part of the circulating refrigerant. It is separated and stored in the gas phase.

  In the subcooling heat exchanger 80, the refrigerant is branched in the subsequent stage and reduced in pressure by the expansion device 82, so that the refrigerant becomes a low-temperature gas-liquid two-phase and the refrigerant discharged from the air-cooled supercooling heat exchanger 33. Heat exchange takes place. The refrigerant having the former low-temperature gas-liquid two-phase flows through the bypass pipe 83. Moreover, the refrigerant | coolant discharged | emitted from the latter air-cooling supercooling heat exchanger 33 flows through the main piping 81 as mentioned above. By this heat exchange, the refrigerant flowing through the main pipe 81 can be cooled, and the specific enthalpy of the refrigerant at the inlet of the use side heat exchanger 22 (described later) can be reduced. As a result, the specific enthalpy difference between the inlet and outlet of the use side heat exchanger 22 is increased, and the cooling capacity is increased. On the other hand, the refrigerant flowing through the bypass pipe 83 evaporates by this heat exchange to become a gas refrigerant, and this gas refrigerant is supplied to the injection port 14 of the compressor 1.

  Of the supercooled refrigerant discharged from the main pipe 81 of the supercooling heat exchanger 80, the remaining refrigerant that has not passed through the bypass pipe 83 is the dryer 15, the blocking valve 8, and the pressure reducing valve 71 (described later). ) And supplied to the receiver 6 of the oxygen adsorption device 91. Here, the dryer 15 is a device that adsorbs moisture in the refrigerant mixed in the refrigeration cycle apparatus and reduces the amount of moisture in the refrigerant circulating in the refrigeration cycle.

  The liquid pipe 70 connecting the receiver 6 and the outdoor unit 40 is provided with a pressure reducing valve 71 for reducing the pressure of the flowing refrigerant. The degree of decompression of the refrigerant is controlled by adjusting the opening degree of the pressure reducing valve 71, thereby controlling the state of the refrigerant in the receiver 6. That is, by controlling the pressure reducing valve 71, the liquid level of the refrigerant is generated in the internal space of the receiver 6, and the state of the refrigerant inside the receiver 6 is made saturated in the gas-liquid two-phase state. it can. Therefore, the pressure reducing valve 71 functions as a receiver liquid level adjusting valve.

  In the receiver 6, oxygen is adsorbed in the same manner as the air conditioner 100. The liquid refrigerant separated in the receiver 6 flows through the liquid side connection pipe 9 and is sent to the expansion device 21. In the expansion device 21, the liquid refrigerant is decompressed to a low pressure to be in a low-pressure two-phase state, and is evaporated by exchanging heat with a use-side medium such as air in the use-side heat exchanger 22 to become a gas refrigerant. Thereafter, the gas refrigerant passes through the gas side connection pipe 10, passes through the blocking valve 11 and the accumulator 12, and returns to the compressor 1. The returned refrigerant is discharged from the compressor 1 again. The refrigerant circulates by such a refrigerant flow, and a refrigeration cycle is formed.

  Also in the refrigerator 200 shown in FIG. 2, the oxygen adsorption device 91 is configured separately from the refrigeration unit 23 and the outdoor unit 40 as in the air conditioner 100 described above. Therefore, similarly to the air conditioner 100, the oxygen adsorption device 91 can be easily attached according to the length of the pipe or the like. Moreover, since it is only necessary to attach oxygen removal, it is possible to reduce the equipment cost of the oxygen adsorbent 65 and the like.

  Moreover, in the refrigerator 200, the refrigerant | coolant which flows through the liquid pipe 7 is a supercooling state by the air cooling supercooling heat exchanger 33 as mentioned above. Thereby, the state of the refrigerant is liquid immediately before the expansion device 21, and the state change of the refrigerant by the expansion device 21 can be favorably controlled. On the other hand, if the refrigerant flowing through the liquid pipe 7 is in a supercooled state, the expansion valve 82 attached to the bypass pipe 83 is temporarily closed, the amount of exchange heat in the supercooling heat exchanger 80 is set to 0 kW, and the main pipe 81 is Even if it is set so that the state of the flowing refrigerant does not change, the state of the refrigerant in the liquid pipe 70 at the inlet of the oxygen adsorption device 91 is also in a supercooled state. Therefore, depending on the size of the receiver 6, the refrigerant inside the receiver 6 may not be in a gas-liquid equilibrium state between the liquid phase 61 and the gas phase 62. In that case, the gas phase 62 does not exist inside the receiver 6.

  However, in the refrigerator 200, the pressure reducing device 71 is provided in the liquid pipe 70 that is the previous stage of the receiver 6. Thereby, even if the state of the refrigerant flowing through the liquid pipe 70 is a supercooled state, the state of the refrigerant at the inlet of the receiver 6 after exiting the decompression device 71 is saturated by adjusting the amount of decompression of the decompression device 71. Can be in a state. Therefore, the refrigerant inside the receiver 6 can be set to a gas-liquid equilibrium state between the liquid phase 61 and the gas phase 62. Thereby, while improving the cooling performance, the gas phase 62 can be more reliably formed inside the receiver 6, and oxygen in the refrigeration cycle can be more reliably adsorbed and removed.

  In the refrigerator 200 shown in FIG. 2, two receivers 6 and 90 are provided. Among these, the filling container 64 containing the oxygen adsorbent 65 is attached to the receiver 6 arranged on the downstream side of the refrigerant flow. As described above, the gas phase 62 is formed inside the receiver 6, but when the amount of refrigerant filled is adjusted so that the state of the refrigerant inside the receiver 90 is in a gas-liquid equilibrium state, A gas phase part also exists inside the receiver 90.

  In each of the receivers 6 and 90, oxygen present in the liquid phase 61 (in the case of the receiver 6) and oxygen present in the gas phase 62 (in the case of the receiver 6) are in an equilibrium state. Therefore, the partial pressure of oxygen in the liquid phase 61 and the partial pressure of oxygen in the gas phase 62 are balanced. Here, when oxygen in the gas phase 62 of the receiver 6 is adsorbed by the oxygen adsorbent 65, the oxygen partial pressure in the gas phase 62 of the receiver 6 decreases. Then, the oxygen in the liquid phase 61 of the receiver 6 moves to the gas phase 62. The oxygen that has moved to the gas phase 62 is adsorbed by the oxygen adsorbent 65 and removed. As a result, the amount of oxygen contained in the circulating refrigerant is reduced.

  And the amount of oxygen contained in the refrigerant | coolant which flows in into the receiver 90 also reduces by the amount of circulating oxygen decreasing. That is, the oxygen concentration in the liquid phase part of the refrigerant of the receiver 90 is lowered. Since the oxygen concentration in the liquid phase refrigerant decreases, the oxygen present in the gas phase portion of the receiver 90 and the oxygen in the liquid phase portion of the receiver 90 are in a non-equilibrium state. Therefore, the oxygen partial pressure of the liquid phase part of the receiver 90 whose concentration has decreased is smaller than the oxygen partial pressure of the gas phase part of the receiver 90, and thus oxygen present in the gas phase part of the receiver 90 is reduced to the liquid in the receiver 90. Move to Aibu. And the refrigerant | coolant of the liquid phase part of the receiver 90 moves to the receiver 6 arrange | positioned downstream, and oxygen adsorption is performed in the receiver 6 as mentioned above.

  As described above, even when the filling container 64 filled with the oxygen adsorbent 65 is attached to only one of the receivers 6 and 90, oxygen not only at the receiver 6 but also at the receiver 90 is removed. Thus, the oxygen concentration in the entire refrigerator 200 can be reduced.

  Of the two receivers 6 and 90, the refrigerant discharged from the heat source side heat exchanger 3 is first supplied to the receiver 90. Therefore, most of the refrigerant is gas-liquid separated in the receiver 90, and the amount of gas-liquid separation in the receiver 6 connected to the subsequent stage of the receiver 90 is not so large. Therefore, the size of the receiver 6 can be reduced. In particular, as described above, the oxygen adsorption device 91 having the receiver 6 is attached to the outer surface of the outdoor unit 40. Therefore, by reducing the receiver 6, the oxygen adsorption device 91 can also be reduced. Thereby, the attachment property of the oxygen adsorption apparatus 91 can be improved.

  Furthermore, as described above, since the refrigerator 200 includes the pressure reducing valve 71, the liquid phase 61 can be reliably formed in the receiver 6 even if the receiver 6 is made smaller. Therefore, the receiver 6 can be further downsized, and the attachment of the oxygen adsorption device 91 can be further improved.

  Further, as described above, when the refrigerant is in a supercooled state, a liquid phase portion is hardly formed inside the receivers 6 and 90. However, since the pressure reducing valve 71 is provided between the receiver 6 and the receiver 90, even if a liquid phase portion is not formed inside the receiver 90 in the previous stage, the pressure reducing valve 71 is controlled, so that In the receiver 6, the gas phase portion 61 can be formed. In particular, in such a case, oxygen in the refrigerant passes through the receiver 90 and reaches the subsequent receiver 6 if a gas phase portion is not formed in the upstream receiver 90. Thereby, the oxygen adsorption performance in the receiver 6 can be improved.

  As described above, by controlling the opening degree of the control valve 71 to form the gas phase 62 inside the receiver 6, more reliable adsorption and removal of oxygen in the refrigeration cycle is achieved. However, after sufficiently adsorbing and removing oxygen, it is not necessary to dare to form the liquid phase 61 in order to adsorb oxygen. Therefore, such adjustment of the opening degree of the control valve 71 is not necessary. Therefore, only in the process of adsorbing oxygen mixed in the refrigeration cycle, the gas connection 62 is generated in the receiver 6 with the liquid connection pipe 9 being saturated, not in the supercooled state, and the supercooled state is obtained after the adsorption of oxygen is finished. You can also.

  That is, when the refrigerator 200 is operated in two stages, for example, a test operation performed after the refrigerator 200 is installed and a normal operation performed after the test operation, the expansion installed in the bypass pipe 83 is performed during the former test operation. The device 82 is fully closed, and the pressure reducing device 71 on the downstream side of the liquid pipe 70 is throttled. As a result, the state of the refrigerant at the inlet of the receiver 6 is saturated, and the gas phase 62 is formed inside the receiver 6. Therefore, it is possible to efficiently remove oxygen during the trial operation. On the other hand, during the latter normal operation, the pressure reducing valve 71 is fully opened and the expansion device 82 installed in the bypass pipe 83 is opened. As a result, the amount of heat exchanged in the supercooling heat exchanger 80 can be increased to increase the degree of supercooling of the refrigerant flowing through the liquid connection pipe 9, and the cooling capacity in the refrigeration unit 23 can be increased.

  Moreover, the following advantages can also be obtained by making the expansion device 82 fully closed to reduce the degree of supercooling during the trial operation. If the degree of supercooling of the refrigerant flowing through the liquid connection pipe 9 is to be increased, that is, the degree of supercooling of the liquid pipe 70 at the inlet of the oxygen adsorption device 91 is to be increased, It is preferable to reduce the opening of the pressure reducing valve 71 and increase the pressure loss at the pressure reducing valve 71. However, according to this, the pressure inside the receiver 6 decreases, and the differential pressure between the pressure at the inlet of the expansion device 21 and the evaporation pressure of the refrigerant in the use side heat exchanger 22 becomes small. And even if the opening degree of the decompression device 21 at the entrance of the use side heat exchanger 22 is fully opened, the pressure loss in the decompression device 21 may be larger than the differential pressure. At this time, the evaporation pressure of the refrigerant in the use side heat exchanger 22 is lower than the design value. Therefore, the operation state of the refrigerator 200 cannot be set as designed. Therefore, during the trial operation, the expansion device 82 is fully closed to reduce the degree of supercooling, whereby the operation state of the refrigerator 200 can be set as designed.

  FIG. 3 is a diagram showing another embodiment of the oxygen adsorption device 91 provided in the refrigeration cycle apparatus of the present embodiment. In the air conditioner 100 and the refrigerator 200 described with reference to FIG. 1 and FIG. 2, the oxygen adsorbing device 100 can be easily removed. The adsorption device 91 was attached. Therefore, even after the oxygen is sufficiently adsorbed and removed, the refrigerant flows through the receiver 6.

  However, the oxygen adsorption device 91 shown in FIG. 3 includes a bypass pipe 78 that bypasses the receiver 6. Then, the receiver 6 is used to adsorb oxygen in the refrigerant during the trial operation, and after the trial operation is completed, the receiver 6 is not used using the bypass pipe 78. Accordingly, particularly when the refrigerant state is supercooled in the refrigerator 200 shown in FIG. 2, the supercooled refrigerant does not flow into the receiver 6, so the receiver 6 is not filled with the liquid phase refrigerant. The amount of refrigerant sealed in the cycle can be reduced.

  In addition to the bypass pipe 78, the oxygen adsorption device 91 shown in FIG. 3 is connected to an upstream air-cooled supercooling heat exchanger 80, and receives a receiver refrigerant introduction pipe 72 for introducing refrigerant, and a downstream refrigeration unit. 23, and a receiver refrigerant outlet pipe 73 for discharging the refrigerant. In addition to the pressure reducing valve 71, the receiver refrigerant introduction pipe 72 is provided with an open / close valve 75 for controlling the flow of the refrigerant. The receiver refrigerant outlet pipe 73 is provided with a check valve 74 that prevents the refrigerant from flowing back. The bypass pipe 78 is provided with an opening / closing valve 76 for controlling the flow of the refrigerant. Furthermore, a filling container 64 is connected to the upper side of the receiver 6 by a connection pipe 63, and the connection pipe 63 is provided with an on-off valve 77 that controls the flow of gas inside the connection pipe 63. ing.

  When the oxygen adsorption device 91 having such a configuration is used, the on-off valves 75, 76, and 77 constituting the oxygen adsorption device 91 are controlled as follows. These controls are performed by the control device unless otherwise specified. A specific control method will be described with reference to FIGS. 4 and 5 as necessary. Here, for convenience of explanation, in the refrigerator 200 provided with the oxygen adsorption device 91 shown in FIG. 3, the operation is performed in two stages, that is, a test operation performed after the installation of the refrigerator 200 and a normal operation performed after the test operation. Take as an example. Note that this test operation is performed for a relatively long time, and is performed separately from evacuation for exhausting the air in the pipe.

  FIG. 4 is a diagram illustrating a flow performed from installation to normal operation when installing the refrigerator according to the present embodiment. FIG. 5 is a table showing the opening / closing timings of the opening / closing valves 75, 76, 77 provided in the oxygen adsorption device 91 shown in FIG. First, construction of the freezing unit 23, the outdoor unit 40, and piping is performed (step S101). Next, installation of the oxygen adsorption device 91 and connection of piping are performed (step S102). Here, immediately after the oxygen adsorber 95 is connected to the pipe and installed (that is, in the factory-shipped state), the pressure reducing valve 71 is opened (fully opened), the on-off valves 75 and 77 are closed, and the on-off valve 76 is closed. Is in a valve open state (see step S101 in FIG. 5). Therefore, when the oxygen adsorption device 91 is installed (step S102), contact of oxygen in the atmosphere with the oxygen adsorbent 65 is prevented.

  Next, after confirming the airtightness of the refrigerator 200, evacuation is performed and the refrigerant is sealed (step S103). Note that the refrigerant enclosed here does not reach the inside of the receiver 6 because the on-off valve 75 is closed. In this way, the amount of refrigerant enclosed can be reduced.

  Then, after evacuation, the compressor 1 is driven to perform a trial run for about 60 hours (step S104). Simultaneously with the start of the trial operation, the open / close valves 75 and 77 are opened, and the open / close valve 76 is closed. Thereby, a refrigerant | coolant flows through the inside of the receiver 6, without bypassing. However, at this time, the liquid level of the refrigerant does not exist in the receiver 6 (the inside is filled with the liquid refrigerant and the gas phase 62 does not exist, or only the gas phase 62 and the liquid phase 61 does not exist. In the absence), the oxygen in the refrigerant may not be sufficiently adsorbed and removed. Therefore, an operator checks the inside of the receiver 6 through the sight glass 67 and adjusts the opening of the pressure reducing valve 71 so that the liquid level of the refrigerant in the receiver 6 is near the center of the sight glass 67. Thereby, the state of the refrigerant in the receiver 6 becomes a gas-liquid two-phase saturated state, and oxygen tends to accumulate inside the receiver 6 and above it. Then, oxygen reaches the oxygen adsorbent 65 through the opened on-off valve 77 and the connection pipe 63, and oxygen in the refrigerant is removed.

  Note that the trial run in the refrigerator 200 is performed for about 60 hours as described above. By this trial operation, oxygen in the refrigerant is adsorbed and removed by the oxygen adsorbent 65. Therefore, if the time for sufficiently adsorbing oxygen is secured, the trial run time can be arbitrarily changed. As a method for determining the test run time, the oxygen ratio in the refrigeration cycle is measured by an oxygen ratio measurement sensor installed in the refrigerator 200, or the refrigerant is extracted and analyzed by gas chromatography. It can be until it becomes below the set oxygen ratio. Moreover, since the adsorption time by the oxygen adsorbent 65 is determined by the type of the oxygen adsorbent 65, it may be set to the reaction time of the oxygen adsorbent 65 with oxygen.

  Returning to FIG. 4, the liquid phase 61 is present inside the receiver 6 even if the compressor 1 is stopped after the trial run is completed. After the oxygen in the refrigerant is sufficiently adsorbed, the filling container 64 containing the oxygen adsorbent 65 becomes unnecessary. Further, since it is not necessary to adsorb oxygen any more, it is not necessary for the refrigerant to flow through the large-capacity receiver 6. Therefore, after the trial run is completed, the liquid refrigerant (liquid phase 61) inside the receiver 6 is discharged to the outside of the receiver 6 (step S105). By discharging the refrigerant to the outside of the receiver 6, the refrigerant in the refrigeration cycle can be used effectively.

  In order to discharge the refrigerant to the outside of the receiver 6, the inflow of the refrigerant to the receiver 6 is stopped by closing the on-off valve 75. Thereby, the internal liquid refrigerant is discharged to the outside of the receiver 6 via the check valve 74. The time for discharging the refrigerant is, for example, about 1 minute. After the refrigerant inside the receiver 6 is discharged to the outside, the open / close valves 75 and 77 are closed, and the open / close valve 76 is opened, so that the refrigerator 200 is normally operated (step). S106). At this time, the state of the pressure reducing valve 71 is maintained in the state of the step of discharging the liquid phase 61 in the receiver 6.

  As described above, the on-off valve 77 provided in the connection pipe 63 is also closed during normal operation. This is due to the following reason. During the normal operation, the oxygen adsorbent 65 is in a state in which almost no oxygen can be adsorbed by the trial operation (step S104). However, for example, when the refrigerator 200 breaks down and is repaired, the refrigerant enclosed in the refrigerator 200 is recovered by the refrigerant recovery machine in order to replace the failed part, and the inside of the refrigerator 200 is opened to the atmosphere. The In other words, since air in the atmosphere enters the inside of the refrigerator 200 when removing the failed part, the oxygen adsorbent 65 is preferably in a state that can sufficiently adsorb oxygen in order to perform a trial run again after repair. . Therefore, at the time of repair, it is preferable that the filling container 64 containing the oxygen adsorbent 65 is also replaced with a new one. From the viewpoint of preventing oxygen in the atmosphere from coming into contact with the new oxygen adsorbent 65 at the time of replacement, the on-off valve 77. Is closed in advance.

  FIG. 6 is a view showing still another embodiment of the oxygen adsorption device 92 provided in the refrigeration cycle apparatus (refrigerator 200) of the present embodiment. In the oxygen adsorption device 91 shown in FIG. 3 and the like, during normal operation, the refrigerant is not introduced into the receiver 6 and bypassed, but the receiver 6 is attached to the refrigerator 200 during normal operation. It remained. On the other hand, in the oxygen adsorption device 92 shown in FIG. 6, the receiver 6 is attached to the refrigerator 200 only when adsorbing and removing oxygen during a trial operation, and has a configuration that can be removed during other normal operations.

  As shown in FIG. 6, in the oxygen adsorption device 92, a removal unit 51 is provided in the middle of the receiver refrigerant introduction pipe 72 and on the downstream side of the refrigerant flow of the on-off valve 75. In addition, a removal part 52 is provided in the middle of the receiver refrigerant outlet pipe 73 and on the downstream side of the refrigerant flow of the check valve 74, and an opening / closing valve 79 is provided further downstream of the removal part 52. Further, a detaching portion 53 is provided in the middle of the connection pipe 63 and between the receiver 6 and the on-off valve 77. The removal parts 51, 52, and 53 are each connected by a flare or a flange. Moreover, the removal parts 51, 52, and 53 may be brazed.

  When the trial operation of the refrigerator 200 is completed and normal operation is performed, as described with reference to FIGS. 4 and 5, the open / close valves 75 and 77 are closed, and the open / close valve 76 is open. . Therefore, the refrigerant passes through the bypass pipe 78 without flowing to the receiver 6. In this state, by removing the receiver 6 from the removing portions 51 and 52, the refrigerator 200 can be normally operated without the receiver 6. Therefore, when the trial operation is performed again for repairing the refrigerator 200, the receiver 6 to which the filling container 64 is connected may be attached again. Thereby, space saving of the installation space of the oxygen adsorption apparatus 92 can be achieved. Moreover, since the receiver 6 can be diverted with respect to the different refrigerator 200, cost reduction can be achieved.

  In addition, when reusing the receiver 6, the filling container 64 is removed from the detaching part 53, and a new filling container 64 is attached, so that a good oxygen adsorption capability can be exhibited in the second and subsequent test operations. it can.

  FIG. 7 is a view showing a modification of the receiver 6 provided in the refrigeration cycle apparatus of the present embodiment. In the oxygen adsorption container 91 described with reference to FIG. 1 and the like, the receiver 6 and the filling container 64 filled with the oxygen adsorbent 65 are configured separately. The arrangement of the oxygen adsorbent 65 is preferably as described above. For example, as shown in FIG. 7, the oxygen adsorbent 65 is arranged inside the receiver 6 and above it. Good. In the internal space of the receiver 6, the oxygen adsorbent 65 is placed on a support member 66 such as a punching metal or a metal net attached inside the receiver 6.

  As described above, in the internal space of the receiver 6, oxygen is directed upward. Therefore, the oxygen adsorbent 65 is disposed inside the receiver 6 and above it, thereby adsorbing and removing oxygen in the refrigerant. be able to. In addition, by arranging the oxygen adsorbent 65 inside the receiver 6, the receiver 6 itself becomes an oxygen adsorption container, and the volume of the oxygen adsorption container can be reduced.

  Although the present embodiment and the modifications thereof have been described above, the present invention is not limited to the above contents.

  For example, in the above-described embodiment, the receiver is exemplified as the refrigerant container to which the filling container 64 filled with the oxygen adsorbent 65 is attached. However, for example, an accumulator may be used.

  Further, in step S104 described with reference to FIG. 4 and the like, the operator has checked the liquid level of the refrigerant visually. For example, a liquid level sensor is provided inside the receiver 6, or the receiver 6 The liquid phase 61 may be confirmed by an external liquid level sensor grasping the liquid level formed inside through the sight glass 67.

  In addition, the above-described embodiments and modifications can be implemented in any combination.

1 compressor 3 heat source side heat exchanger 4 expansion device 6 receiver (refrigerant container, first refrigerant container)
12 Accumulator 20 Indoor unit (Usage unit)
Refrigeration unit (use side unit)
21 expansion device 22 use side heat exchanger 33 air cooling supercooling heat exchanger (supercooling device)
40 Outdoor unit (heat source side unit)
61 Liquid phase 62 Gas phase 64 Filling container (container)
65 Oxygen adsorbent (oxygen adsorption part)
71 Pressure reducing valve (pressure reducing device)
80 Supercooling heat exchanger (supercooling device)
82 expansion device 90 receiver (refrigerant container, second refrigerant container)
91 Oxygen adsorption device (oxygen adsorption unit)
92 Oxygen adsorption device (oxygen adsorption unit)
100 Air conditioner (use side unit)
200 Refrigerator (User side unit)

Claims (9)

A heat source side unit comprising at least a compressor that compresses the refrigerant, and a heat source side heat exchanger that heats or cools the refrigerant, and
A utilization side unit comprising at least a utilization side heat exchanger for heating or cooling the refrigerant;
A refrigerant container having an internal space that separates the refrigerant into a liquid phase and a gas phase; and an oxygen adsorption unit that adsorbs oxygen in the internal space; and separate from the heat source side unit and the use side unit An oxygen adsorption unit comprising:
A refrigeration cycle apparatus comprising: the heat source side unit, the use side unit, and the oxygen adsorption unit, and a pipe through which the refrigerant flows in a predetermined manner.   The refrigeration cycle apparatus according to claim 1, wherein the refrigerant container is a receiver provided at a position where the liquid refrigerant flows in the pipe. The oxygen adsorbing portion is accommodated in a storage container,
The storage container storing the oxygen adsorbing portion is provided separately from the refrigerant container so as to communicate with the gas phase inside the refrigerant container above the refrigerant container. The refrigeration cycle apparatus according to claim 1 or 2. A second refrigerant container that is different from the first refrigerant container that is the refrigerant container, and is connected to the heat source side heat exchanger so that the refrigerant after heat exchange in the heat source side heat exchanger is supplied. A refrigerant container,
The refrigeration cycle apparatus according to claim 1 or 2, wherein the refrigerant discharged from the second refrigerant container is supplied to the first refrigerant container.   The refrigeration cycle apparatus according to claim 4, wherein the second refrigerant container is a receiver provided at a position where the liquid refrigerant flows in the pipe.   A decompression device is provided between the first refrigerant container and the second refrigerant container to depressurize the refrigerant supplied to the first refrigerant container so that the state of the refrigerant in the first refrigerant container is saturated. The refrigeration cycle apparatus according to claim 4 or 5, wherein the refrigeration cycle apparatus is provided.   A subcooling between the first refrigerant container and the second refrigerant container, in which the refrigerant supplied to the first refrigerant container is supercooled on the upstream side of the refrigerant flow as viewed from the decompression device. The refrigeration cycle apparatus according to claim 6, further comprising an apparatus.   The refrigeration cycle apparatus according to claim 1, wherein the refrigerant includes a hydrofluoroolefin refrigerant.   The oxygen adsorbing part is configured to include iron powder, and the oxygen adsorbing part adsorbs oxygen mixed in the refrigerant by oxidizing the iron of the powder into iron oxide. The refrigeration cycle apparatus according to claim 1 or 2, wherein

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