JP2008209044A - Refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress generation of pulsation and to perform a stable operation of a cycle in a refrigerating cycle device comprising an expander and a compressor. <P>SOLUTION: The compressor 10 comprises a compressing mechanism and a first sealed container receiving the compressing mechanism. The expander 12 comprises an expanding mechanism and a second sealed container receiving the expanding mechanism. A first oil reservoir and a first refrigerant space in which a refrigerant discharged from the compressing mechanism or a refrigerant sucked by the compressing mechanism is filled, are formed in the first sealed container. A second oil reservoir and a second refrigerant space not communicated with a suction hole and a discharge hole of the expanding mechanism are formed in the second sealed container. The first sealed container of the compressor 10 and the second sealed container of the expander 12 are connected through an oil equalization pipe 14 and a pressure equalization pipe 15. The pressure equalization pipe 15 is provided with a pressure loss generating portion 16 for providing the refrigerant flowing in the pressure equalization pipe 15 with pressure loss. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus including a compressor and an expander.

  In a so-called vapor compression refrigeration cycle apparatus, an expander separated from a compressor, that is, a refrigeration cycle apparatus using a so-called separation type expander is known (for example, see Non-Patent Document 1). FIG. 9 shows an example of a refrigeration cycle apparatus including a separation type expander.

  The refrigeration cycle apparatus 101 includes a compressor 102, a radiator 103, an expander 104, and an evaporator 105 connected in order. The refrigerant charged in the refrigeration cycle apparatus 101 is compressed by the compressor 102 and is changed from a low pressure state to a high temperature and high pressure state, and is cooled by exchanging heat with air, water and the like in the radiator 103 to be in a low temperature state. The refrigerant flowing out of the radiator 103 expands in the expander 104 and changes from a high pressure state to a low temperature and low pressure state. The refrigerant that has flowed out of the expander 104 is heated by exchanging heat with air, water, or the like in the evaporator 105, becomes an intermediate temperature state, is compressed again in the compressor 102, and thereafter repeats the above-described operation.

  A generator (not shown) is connected to the expander 104 via a rotating shaft (not shown). In the expander 104, the rotating shaft rotates as the refrigerant expands, and the generator is driven by the rotation of the rotating shaft. Thereby, the power of the expansion energy in the process of expansion of the refrigerant can be recovered. Therefore, the efficiency of the refrigeration cycle can be improved by using the recovered power as driving energy for the compressor 102.

By the way, in this kind of refrigeration cycle apparatus 101, the compressor 102 generally includes a sealed container 102a and a compression mechanism 102b accommodated in the sealed container 102a. The expander 104 includes a sealed container 104a and an expansion mechanism 104b accommodated in the sealed container 104a. Here, since both the compression mechanism 102b and the expansion mechanism 104b have sliding portions, oil for lubrication is required. Therefore, oil reservoirs 102c and 104c are provided in the sealed container 102a of the compressor 102 and the sealed container 104a of the expander 104, respectively. The sealed container 102a of the compressor 102 and the sealed container 104a of the expander 104 are connected to each other via an oil equalizing pipe 107 and a pressure equalizing pipe 108 in order to keep the oil level of the oil reservoirs 102c and 104c constant. ing.
“Results of FY2002, Research and Development of Energy-Effective Utilization Fundamental Technology, Development of Two-Phase Flow Expander / Compressor for CO2 Air Conditioner”, New Energy and Industrial Technology Development Organization, March 2003, p. 5-37

  In the refrigeration cycle apparatus 101, the suction pipe 111 and the discharge pipe 112 of the expander 104 pass through the sealed container 104a and are directly connected to the expansion mechanism 104b. For this reason, in the expander 4, the refrigerant sucked into the expansion mechanism 104b and the refrigerant discharged from the expansion mechanism 104b do not circulate in the sealed container 104a. Therefore, the sealed container 104a is a sealed space that is not directly connected to the refrigerant circuit.

  Normally, oil is discharged together with the refrigerant from the expansion mechanism 104b. However, when oil is discharged from the discharge pipe 112, the amount of oil in the oil reservoir 104c decreases. Since the sealed container 102a of the compressor 102 and the sealed container 104a of the expander 104 are connected by an oil equalizing pipe 107 and a pressure equalizing pipe 108, when the amount of oil in the oil reservoir 104c decreases, the refrigerant or oil corresponding to the reduced volume Flows into the sealed container 104a from the sealed container 102a. At this time, since the viscosity of the oil is 100 times higher than the viscosity of the refrigerant, the speed of the refrigerant moving in the pressure equalizing pipe 108 is larger than the speed of the oil moving in the oil equalizing pipe 107. For this reason, the refrigerant flowing from the pressure equalizing pipe 108 has a larger volume than the oil flowing from the oil equalizing pipe 107 with respect to the sealed container 104a. As a result, most of the oil flowing out from the sealed container 104a is supplemented by the refrigerant from the pressure equalizing pipe 108, so that the oil in the oil reservoir 104c gradually decreases. However, the reduction of the oil in the oil reservoir 104c will eventually cause a poor lubrication of the expansion mechanism 104b and cause a decrease in the reliability of the refrigeration cycle apparatus 101.

  The present invention has been made in view of such points, and an object of the present invention is a refrigeration cycle apparatus including a compressor and an expander connected via an oil equalizing pipe and a pressure equalizing pipe, An object of the present invention is to provide a refrigeration cycle apparatus capable of preventing a failure due to poor lubrication of a machine and performing a stable operation.

  A refrigeration cycle apparatus according to the present invention includes a compressor provided with a compression mechanism and a first sealed container that accommodates the compression mechanism, a radiator, an expansion mechanism having a suction hole and a discharge hole, and the expansion mechanism. A refrigeration cycle apparatus including an expander including a second sealed container to be accommodated, and an evaporator, wherein the first oil reservoir for storing oil and the compression mechanism are stored in the first sealed container. A first refrigerant space filled with a refrigerant discharged from the refrigerant or a refrigerant sucked into the compression mechanism, a second oil reservoir for storing oil in the second sealed container, and an expansion mechanism A second refrigerant space that does not communicate with the suction hole and the discharge hole is formed, and an oil equalizing pipe that connects the first oil reservoir and the second oil reservoir, and connects the first refrigerant space and the second refrigerant space. A pressure equalizing pipe and a pressure equalizing pipe provided on the front And the pressure loss generating unit which gives a pressure loss in the refrigerant flowing through the equalizing pipe, but with a.

  The pressure loss generator may be a throttle mechanism.

  The pressure loss generating unit may be a pipe formed in a spiral shape.

  The pressure loss generation unit may be a sudden expansion part in which the flow path cross-sectional area increases discontinuously or a sudden reduction part in which the flow path cross-sectional area decreases discontinuously.

  The pressure loss generator may be an orifice.

  The flow path cross-sectional area of the orifice may increase from the first sealed container side toward the second sealed container side.

  A plurality of the pressure loss generators may be provided.

  The pressure loss generator may be provided closer to the second sealed container than an intermediate position of the pressure equalizing pipe.

  The pressure loss generator may be provided in the second sealed container.

  The refrigeration cycle may be filled with carbon dioxide as a refrigerant.

  According to the refrigeration cycle apparatus according to the present invention, when the volume of the oil stored in the second sealed container is reduced, the refrigerant flowing from the first sealed container toward the second sealed container in the pressure equalizing pipe is pressurized. Movement is restricted by the loss generation unit. Therefore, oil flowing in the oil equalizing pipe from the first sealed container toward the second sealed container can be preferentially supplied to the second sealed container. Therefore, it becomes possible to prevent the lubrication failure of the expander and to maintain the reliability of the refrigeration cycle apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< Overall configuration of refrigeration cycle apparatus >>
FIG. 1 shows a refrigeration cycle apparatus 9 according to an embodiment of the present invention. The refrigeration cycle apparatus 9 according to the embodiment includes a compressor 10, a radiator 11, an expander 12, and an evaporator 13, which are sequentially connected through refrigerant pipes 17, 18, 19, and 20. And constitutes a refrigerant circuit. The compressor 10 and the expander 12 are connected via an oil equalizing pipe 14 and a pressure equalizing pipe 15.

  This refrigerant circuit is filled with carbon dioxide as a refrigerant. This refrigerant is in a supercritical state in the high-pressure side portion of the refrigerant circuit (that is, the portion from the compressor 10 through the radiator 11 to the expander 12). However, the refrigerant may be other than carbon dioxide. As will be described later, a first oil reservoir 10b (see FIG. 2) and a second oil reservoir 12b (see FIG. 3) are formed in the compressor 10 and the expander 12, respectively. PAG is enclosed as oil in 10b and the second oil reservoir 12b. However, the oil may be other than PAG.

《Compressor configuration》
FIG. 2 is a longitudinal sectional view of the compressor 10. The compressor 10 has the 1st airtight container 10a, the compression mechanism 10d accommodated in the 1st airtight container 10a, and the electric motor 10e which drives the compression mechanism 10d. The compression mechanism 10d and the electric motor 10e are connected by a rotating shaft 10f, and an oil pump 10g is provided below the rotating shaft 10f.

  In the present embodiment, the first sealed container 10a is a substantially cylindrical sealed container that is formed in a substantially cylindrical shape with its upper end and lower end closed, and whose vertical length is longer than the horizontal length. However, the first sealed container 10a may be a horizontally long sealed container. The compressor 10 is a so-called high-pressure dome type compressor, and the first sealed container 10a is filled with a high-pressure refrigerant discharged from the compression mechanism 10d.

  A first oil reservoir 10b in which oil is stored is formed at the bottom of the first sealed container 10a. The oil pump 10g pumps up the oil in the first oil reservoir 10b as the rotary shaft 10f rotates, and is immersed in the oil in the first oil reservoir 10b. Although the kind of oil pump 10g is not limited at all, here, the oil pump 10g is formed of a trochoid pump.

  A plate 101 is fixed to the lower inner wall of the first sealed container 10a, and a bearing 10m is fixed to the plate 101. The bearing 10m rotatably supports the lower part of the rotating shaft 10f. The rotary shaft 10f is provided with an oil supply path (not shown) that guides the oil pumped up by the oil pump 10g to the compression mechanism 10d.

  The electric motor 10e includes a stator 10n fixed to the inner wall of the first sealed container 10a and a rotor 10o fixed to the rotating shaft 10f. The electric motor 10e is disposed substantially at the center in the vertical direction of the first sealed container 10a.

  Although the specific configuration of the compression mechanism 10d is not limited at all, in this embodiment, the compression mechanism 10d is configured by a scroll type compression mechanism. However, the compression mechanism 10d may be another type of compression mechanism such as a rotary type.

  A discharge pipe 10h is connected to the upper wall of the first sealed container 10a. A suction pipe 10i that guides the suction refrigerant to the compression mechanism 10d is connected to the upper side surface of the first sealed container 10a. A hole 10j is formed above the oil level in the first sealed container 10a, and a pressure equalizing tube 15 is inserted into the hole 10j. The pressure equalizing pipe 15 opens toward the first refrigerant space 10c in the first sealed container 10a. A hole 10k is formed below the hole 10j of the first sealed container 10a. An oil equalizing pipe 14 is inserted into the hole 10k. The oil equalizing pipe 14 opens toward the first oil reservoir 10b.

<Structure of expander>
FIG. 3 is a longitudinal sectional view of the expander 12. The expander 12 includes a second sealed container 12a, an expansion mechanism 12f accommodated in the second sealed container 12a, and a generator 12d to which power is supplied from the expansion mechanism 12f. The expansion mechanism 12f and the generator 12d are connected by a rotating shaft 12e, and an oil pump 12g is provided below the rotating shaft 12e.

  The second sealed container 12a of the expander 12 is also formed in a substantially cylindrical shape whose upper end and lower end are closed, and is a vertically long sealed container whose vertical length is longer than the horizontal length. However, the second sealed container 12a may be a horizontally long sealed container. The expander 12 is a so-called high-pressure dome type expander, and the second sealed container 12a is filled with a high-pressure refrigerant introduced from the pressure equalizing pipe 15.

  A second oil reservoir 12b is formed at the bottom of the second sealed container 12a. The oil pump 12g pumps up the oil in the second oil reservoir 12b as the rotary shaft 12e rotates, and is immersed in the oil in the second oil reservoir 12b. In this embodiment, the oil pump 12g of the expander 12 is also constituted by a trochoid pump.

  A plate 12m is fixed to the lower inner wall of the second sealed container 12a, and a bearing 12n is fixed to the plate 12m. The bearing 12n rotatably supports the lower part of the rotary shaft 12e. The rotating shaft 12e is provided with an oil supply path (not shown) that guides the oil pumped up by the oil pump 12g to the expansion mechanism 12f.

  The generator 12d is configured by a stator 12o fixed to the inner wall of the second hermetic container 12a and a rotor 12p fixed to the rotating shaft 12e. The generator 12d is arranged at the substantially center in the vertical direction of the second sealed container 12a.

  In this embodiment, the expansion mechanism 12f is configured by a scroll type expansion mechanism. However, the expansion mechanism 12f may be another type of expansion mechanism such as a rotary type. The specific configuration of the expansion mechanism 12f is not limited at all.

  A suction pipe 12h is connected to the upper side surface of the second sealed container 12a. The suction pipe 12h penetrates the side surface of the second sealed container 12a and is connected to the suction hole 12q of the expansion mechanism 12f. A discharge pipe 12i that guides the refrigerant discharged from the expansion mechanism 12f is connected to the upper side surface of the second sealed container 12a. The discharge pipe 12i penetrates the side surface of the second sealed container 12a and is connected to the discharge hole 12r of the expansion mechanism 12f. A hole 12j is formed above the oil level in the second sealed container 12a, and a pressure equalizing pipe 15 is inserted into the hole 12j. The pressure equalizing pipe 15 opens toward the second refrigerant space 12c in the second sealed container 12a. The second refrigerant space 12c does not communicate with the suction hole 12q and the discharge hole 12r of the expansion mechanism 12f. A hole 12l is formed below the hole 12j of the second sealed container 12a. An oil equalizing pipe 14 is inserted into the hole 12l. The oil equalizing pipe 14 opens toward the second oil reservoir 12b.

《Configuration of oil equalizing pipe and pressure equalizing pipe》
The oil leveling pipe 14 communicates the first oil reservoir 10b in the first sealed container 10a of the compressor 10 and the second oil reservoir 12b in the second sealed container 12a of the expander 12 to transport oil. In this embodiment, the oil equalizing pipe 14 is constituted by a copper pipe. However, the type of the oil equalizing pipe 14 is not particularly limited.

  One end of the pressure equalizing pipe 15 passes through the hole 10j of the first sealed container 10a of the compressor 10 and extends into the first sealed container 10a. The other end of the pressure equalizing tube 15 is fitted in the hole 12j of the second sealed container 12a of the expander 12. As shown in FIG. 1, a pressure loss generator 16 that generates a pressure loss when the refrigerant flows is provided in the middle of the pressure equalizing pipe 15. In other words, the pressure equalizing pipe 15 is spanned between the first sealed container 10a and the second sealed container 12a, and has the pressure loss generating portion 16 therebetween.

  The pressure loss generating unit 16 is a part that positively generates a pressure loss with respect to the refrigerant. For example, the pressure loss generator 16 is a part that generates more pressure loss than before and after the pressure loss generator 16. Further, for example, the pressure loss generating unit 16 is a part that generates more pressure loss than a straight pipe having a constant channel cross-sectional area.

<Operation of refrigeration cycle device>
During operation of the refrigeration cycle device 9 (see FIG. 1), the refrigerant discharged from the compressor 10 is in a supercritical state. The high-temperature refrigerant discharged from the compressor 10 dissipates heat in the radiator 11 and expands in the expander 12 after the temperature drops. The refrigerant discharged from the expander 12 is sucked into the compressor 10 after being evaporated by the evaporator 13.

  At this time, the temperature in the first sealed container 10a is higher than room temperature (for example, about 80 ° C., hereinafter simply referred to as high temperature), while the temperature in the second sealed container 12a is room temperature (for example, about 15 ° C.). ) Although details will be described later, in the present embodiment, the first sealed container 10a and the second sealed container 12a are connected by the oil equalizing pipe 14 and the pressure equalizing pipe 15, and the pressure equalizing pipe 15 is provided with the pressure loss generating portion 16. The oil level of the first oil reservoir 10b of the first sealed container 10a and the oil level of the second oil reservoir 12b of the second sealed container 12a are maintained at substantially the same height position.

<< Reason why the suction pipe 12h and the discharge pipe 12i are directly connected to the expansion mechanism 12f >>
As described above, the first sealed container 10a of the compressor 10 and the second sealed container 12a of the expander 12 are the oil equalizing pipe 14 and the pressure equalizing pipe 15 in order to keep the oil levels of the oil reservoirs 10b and 12b constant. It is connected. For this reason, if the suction pipe 12h of the expander 12 is not directly connected to the expansion mechanism 12f but is opened toward the second refrigerant space 12c of the second sealed container 12a, the refrigerant is the compressor 10, the radiator. 11, the expander 12, and the evaporator 13 do not flow in this order, and a short circuit occurs between the compressor 10 and the expander 12 through the oil equalizing pipe 14 or the pressure equalizing pipe 15. The same applies to the case where the discharge pipe 12i of the expander 12 is not directly connected to the expansion mechanism 12f but is opened toward the second refrigerant space 12c of the second sealed container 12a. Therefore, in order to prevent such a short circuit, the suction pipe 12h and the discharge pipe 12i of the expander 12 are directly connected to the expansion mechanism 12f.

  Thus, in the expander 12, since the refrigerant sucked or discharged does not circulate in the second sealed container 12a, the inside of the second sealed container 12a is a sealed space that is not directly connected to the refrigerant circuit. It becomes.

《Oil behavior in compressor》
Incidentally, in the compressor 10, the oil in the first oil reservoir 10b is pumped up by the oil pump 10g and supplied to the compression mechanism 10d. The oil supplied to the compression mechanism 10d seals the gap of the compression mechanism 10d and also lubricates the sliding surface. Part of the oil that has been sealed or lubricated by the compression mechanism 10d is discharged together with the refrigerant from the compression mechanism 10d toward the first refrigerant space 10c in the first sealed container 10a. Since the specific gravity of the refrigerant and the oil is greatly different, the oil discharged together with the refrigerant is separated from the refrigerant when flowing through the first refrigerant space 10c and returns to the first oil reservoir 10b.

《Oil behavior in expander》
Also in the expander 12, the oil in the second oil reservoir 12b is pumped up by the oil pump 12g and supplied to the expansion mechanism 12f. The oil supplied to the expansion mechanism 12f seals the clearance of the expansion mechanism 12f and lubricates the sliding surface. However, in the expander 12, the refrigerant is directly discharged from the expansion mechanism 12f to the outside of the second sealed container 12a through the discharge pipe 12i. Therefore, the oil discharged together with the refrigerant from the expansion mechanism 12f flows out of the second sealed container 12a without being collected in the oil reservoir 12b of the second sealed container 12a.

<Action of pressure loss generator>
However, when oil flows out of the second sealed container 12a, the amount of oil in the second oil reservoir 12b decreases. Here, the first airtight container 10a and the second airtight container 12a are connected by the oil equalizing pipe 14 and the pressure equalizing pipe 15, and since the second airtight container 12a is an airtight space as described above, the oil in the second oil reservoir 12b. When the amount decreases, refrigerant or oil corresponding to the reduced volume flows from the first sealed container 10a to the second sealed container 12a through the pressure equalizing pipe 15 and the oil equalizing pipe 14, respectively. However, at this time, since the viscosity of the oil is 100 times higher than the viscosity of the refrigerant, if there is no pressure loss generator 16, the refrigerant flowing in the pressure equalizing pipe 15 rather than the moving speed of the oil flowing in the oil equalizing pipe 14. The movement speed of is much faster.

  However, according to the present embodiment, the pressure loss generating section 16 is provided in the pressure equalizing pipe 15, and the pressure loss generating section 16 hinders the original movement of the refrigerant, so that the first sealed container 10a to the second sealed container. The amount of refrigerant flowing into 12a can be limited. Therefore, the amount of oil flowing from the first sealed container 10a to the second sealed container 12a through the oil equalizing pipe 14 is increased by an amount corresponding to a decrease in the amount of refrigerant flowing from the first sealed container 10a to the second sealed container 12a through the pressure equalizing pipe 15. be able to. As a result, the oil is preferentially supplied from the first oil reservoir 10b of the compressor 10 to the second oil reservoir 12b of the expander 12 so as to compensate for the decrease in the oil flowing out of the second sealed container 12a through the discharge pipe 12i. can do. Therefore, it becomes possible to prevent the lubrication failure of the expander 12, and the reliability of the refrigeration cycle apparatus 9 can be improved.

<Specific configuration of pressure loss generator>
The pressure loss generating unit 16 may be any unit that generates pressure loss with the flow of the refrigerant and delays the flow rate of the refrigerant, and its specific configuration is not limited at all. Below, the suitable specific example of the pressure loss generation | occurrence | production part 16 is given and they are demonstrated.

  As shown in FIG. 4, the pressure loss generator 16 may be formed by a throttle mechanism 21 including a valve whose opening degree is adjustable. Here, the “throttle mechanism” is a mechanism that gives a throttling action to the refrigerant, and specifically, a mechanism having a variable channel cross-sectional area. Note that the throttling mechanism 21 (for example, the opening degree of the valve) can be freely adjusted, but the control method is not limited at all. For example, the throttle mechanism 21 may be formed by an electromagnetic valve whose opening degree can be adjusted, and this electromagnetic valve may be electrically controlled.

  If the pressure loss generating unit 16 is formed by the throttle mechanism 21 in this way, the magnitude of the pressure loss of the refrigerant can be freely adjusted by adjusting the throttle degree of the throttle mechanism 21 (for example, the opening degree of the valve). Can be adjusted. Therefore, the moving amount of the refrigerant can be adjusted in accordance with the amount of oil supplied to the expander 12.

  In addition, since the throttle mechanism 21 such as a valve can be easily attached to the pressure equalizing pipe 15, the assemblability can be improved.

  Moreover, since the inside of the compressor 10 is usually hotter than the inside of the expander 12, if the refrigerant flows from the compressor 10 to the expander 12 through the pressure equalizing pipe 15, the expander 12 may be heated. However, if the pressure loss generating unit 16 is formed by the throttle mechanism 21, the amount of refrigerant flowing through the pressure equalizing pipe 15 can be reduced by narrowing (closing) the throttle mechanism 21 as much as possible in a steady state. The heat transfer action through 15 can be suppressed.

  By the way, when the high-temperature refrigerant in the compressor 10 flows into the expander 12 through the pressure equalizing pipe 15, the low-temperature refrigerant in the expander 12 expands by being heated, and a part of the expanded refrigerant expands. The inside may flow in the opposite direction from the expander 12 side to the compressor 10 side. Thereafter, the refrigerant again moves from the compressor 10 side to the expander 12 side, and thereafter, such a pattern may be repeated. As a result, pulsation may occur in the pressure equalizing tube 15. However, such pulsation can be suppressed by providing the pressure loss generating portion 16 in the pressure equalizing pipe 15.

  As shown in FIG. 5, a part of the pressure equalizing pipe 15 may be formed in a spiral shape, and the spiral pipe 22 may be used as the pressure loss generator 16. Furthermore, you may arrange | position the helical piping 22 so that one or both of the 1st airtight container 10a and the 2nd airtight container 12a may be enclosed. In addition, when arrange | positioning the helical piping 22 so that the 1st airtight container 10a may be enclosed, since the compression mechanism 10d which is a heating source is arrange | positioned in the upper part in the 1st airtight container 10a, it is the 1st airtight container 10a. It is preferable to extend the spiral pipe 22 from the lower side to the upper side of the first sealed container 10a so that the refrigerant flowing toward the upper side goes from the low temperature part to the high temperature part. On the other hand, when the spiral pipe 22 is disposed so as to surround the second sealed container 12a, the expansion mechanism 12f, which is a cooling source, is disposed at the upper part in the second sealed container 12a. It is preferable to extend the spiral pipe 22 from the lower side to the upper side of the second hermetic container 12a so that the refrigerant flowing toward the lower side moves from the high temperature part to the low temperature part. Note that the number of turns of the spiral pipe 22 is not particularly limited, but it is preferable that the number of turns is larger from the viewpoint of promoting heat exchange between the refrigerant in the spiral pipe 22 and the sealed containers 10a and 12a.

  By adopting the above configuration, it is possible not only to suppress the movement of the refrigerant by giving a pressure loss, but also to effectively use the heat radiated from each of the sealed containers 10a and 12a. That is, the refrigerant moving to the first sealed container 10a can be heated, and the refrigerant moving to the second sealed container 12a can be given a cooling effect. And the efficiency of the refrigeration cycle can be improved.

  In addition, as shown in FIG. 5, the pressure loss generation | occurrence | production part 16 may be provided with two or more.

  As shown in FIG. 6, the pressure loss generation unit 16 may be formed by a sudden enlargement unit 23 or a sudden reduction unit 24. The sudden expansion portion 23 is a portion where the flow path cross-sectional area increases discontinuously, and the sudden reduction portion 24 is a portion where the flow passage cross-sectional area decreases discontinuously.

  Specifically, in the example shown in FIG. 6, the pressure loss generating unit 16 is formed by changing the volume of a part of the pressure equalizing pipe 15 to be larger or smaller than the volume of the other straight pipe part. From the viewpoint of increasing the pressure loss, the larger the volume change amount, the better. In addition, the greater the number of repetitions of the rapid enlargement unit 23 and the rapid reduction unit 24, the greater the effect.

  According to the above configuration, a large pressure loss can be obtained by repeatedly changing the flow path cross-sectional area of the pressure equalizing pipe 15 through which the refrigerant moves. Further, as described above, pulsation may occur in the pressure equalizing tube 15, but according to the above configuration, a certain amount of space is secured in the pressure equalizing tube 15, and thus pulsation can be absorbed in this space. .

  Further, as shown in FIG. 7, the pressure loss generator 16 is formed so that the flow path cross-sectional area increases from the first sealed container 10 a side of the compressor 10 toward the second sealed container 12 a side of the expander 12. May be. Thus, the effect which suppresses a refrigerant | coolant movement is efficiently acquired by enlarging the flow-path cross-sectional area by the side of the 2nd airtight container 12a rather than the 1st airtight container 10a side.

  Although a specific structure for realizing such a pressure loss generating unit 16 is not limited at all, for example, in order to obtain such a pressure loss generating unit 16, a member such as an orifice 25 whose cross-sectional area changes May be installed in the pressure equalizing pipe 15. Of course, a part of the pressure equalizing pipe 15 may be the orifice 25. In the pressure loss generating unit 16, when the refrigerant moves from the first sealed container 10a toward the second sealed container 12a, the cross-sectional area of the flow path increases, so that the refrigerant is decompressed and supplied to the second sealed container 12a. Is done. Although the pulsation may occur as described above, since the refrigerant already decompressed by the pressure loss generator 16 is supplied to the second sealed container 12a, rapid expansion of the refrigerant in the second sealed container 12a occurs. It is prevented and pulsation can be effectively suppressed.

  In addition, the pressure loss generation unit 16 is provided on the second sealed container 12a side from the intermediate position of the pressure equalizing pipe 15 (intermediate position between the opening end on the compressor side of the pressure equalizing pipe 15 and the opening end on the expander side). (See FIG. 4). That is, the pressure loss generating unit 16 may be provided on the second sealed container 12a side from 1/2 of the entire length. Alternatively, as shown in FIG. 8, a part of the pressure equalizing tube 15 may be extended into the second sealed container 12a, and the pressure loss generator 16 may be provided in the second sealed container 12a.

  As described above, the main factor causing pulsation in the pressure equalizing pipe 15 is that the refrigerant flowing from the first sealed container 10a rapidly expands in the second sealed container 12a. That is, the main source of pulsation is in the second sealed container 12a. However, if the pressure loss generating unit 16 is provided on the second sealed container 12a side or in the second sealed container 12a as described above, fluctuations can be prevented in the vicinity of the generation source and the influence on the refrigeration cycle apparatus 9 can be prevented. Can be suppressed. Further, when the pressure loss generator 16 is provided in the second sealed container 12a, a pipe for a pressure equalizing pipe connected to the second sealed container 12a (in this case, this pipe constitutes a part of the pressure equalizing pipe. This eliminates the need to add new parts. Therefore, the pressure loss generating part 16 can be formed when the second sealed container 12a is assembled, and it is possible to contribute to the productivity improvement of the refrigeration cycle apparatus 9.

  In the present embodiment, the refrigerant of the refrigeration cycle apparatus 9 is carbon dioxide. However, the refrigerant is not limited to carbon dioxide. Further, the types of the pressure equalizing pipe 15 and the oil equalizing pipe 14 are not limited at all. However, since oil having a higher viscosity than the refrigerant flows in the oil leveling pipe 14, the oil leveling pipe 14 is a pipe with little pressure loss, for example, a short, thick, straight, from the viewpoint of smoothing the oil flow. A tube is preferred.

  As described above, the present invention is useful for a refrigeration cycle apparatus including a compressor and an expander, such as an air conditioner, a water heater, a refrigerator, a refrigerator, and a dehumidifier.

Refrigerant circuit diagram of refrigeration cycle apparatus according to an embodiment The longitudinal cross-sectional view of the compressor which concerns on embodiment Vertical section of an expander according to an embodiment Refrigerant circuit diagram of refrigeration cycle apparatus according to an embodiment Refrigerant circuit diagram of refrigeration cycle apparatus according to an embodiment Longitudinal sectional view of the pressure loss generating part according to the embodiment Longitudinal sectional view of the pressure loss generating part according to the embodiment Refrigerant circuit diagram of refrigeration cycle apparatus according to an embodiment Refrigerant circuit diagram of conventional refrigeration cycle equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 9 Refrigeration cycle apparatus 10 Compressor 10a 1st airtight container 10b 1st oil reservoir 10c 1st refrigerant | coolant space 10d Compression mechanism 11 Radiator 12 Expander 12a 2nd airtight container 12b 2nd oil reservoir 12c 2nd refrigerant | coolant space 12f Expansion mechanism 12q Suction hole 12r Discharge hole 13 Evaporator 14 Oil equalization pipe 15 Pressure equalization pipe 16 Pressure loss generation part 21 Throttle mechanism 22 Pipe formed in a spiral 23 Rapid expansion part 24 Rapid reduction part 25 Orifice

Claims (10)

A compressor including a compression mechanism and a first sealed container that accommodates the compression mechanism; a radiator; an expansion mechanism having a suction hole and a discharge hole; and a second sealed container that accommodates the expansion mechanism. A refrigeration cycle apparatus comprising an expander and an evaporator,
A first oil reservoir for storing oil and a first refrigerant space filled with a refrigerant discharged from the compression mechanism or a refrigerant sucked into the compression mechanism are formed in the first sealed container,
A second oil reservoir that stores oil and a second refrigerant space that does not communicate with the suction hole and the discharge hole of the expansion mechanism are formed in the second sealed container,
An oil equalizing pipe connecting the first oil reservoir and the second oil reservoir;
A pressure equalizing pipe connecting the first refrigerant space and the second refrigerant space;
A refrigeration cycle apparatus comprising: a pressure loss generating unit that is provided in the pressure equalizing pipe and gives a pressure loss to the refrigerant flowing in the pressure equalizing pipe. The refrigeration cycle apparatus according to claim 1,
The pressure loss generating unit is a refrigeration cycle apparatus that is a throttle mechanism. The refrigeration cycle apparatus according to claim 1,
The pressure loss generating unit is a refrigeration cycle apparatus that is a spirally formed tube. The refrigeration cycle apparatus according to claim 1,
The pressure loss generation unit is a refrigeration cycle apparatus that is a sudden expansion part in which a flow passage cross-sectional area increases discontinuously or a sudden reduction part in which a flow passage cross-sectional area decreases discontinuously. The refrigeration cycle apparatus according to claim 1,
The refrigeration cycle apparatus, wherein the pressure loss generating unit is an orifice. The refrigeration cycle apparatus according to claim 5,
The refrigeration cycle apparatus in which the flow path cross-sectional area of the orifice increases from the first sealed container side to the second sealed container side. In the refrigeration cycle apparatus according to any one of claims 1 to 6,
The refrigeration cycle apparatus in which a plurality of the pressure loss generation units are provided. In the refrigeration cycle apparatus according to any one of claims 1 to 7,
The pressure loss generating unit is a refrigeration cycle apparatus provided closer to the second sealed container than an intermediate position of the pressure equalizing pipe. In the refrigeration cycle apparatus according to any one of claims 1 to 7,
The pressure loss generating unit is a refrigeration cycle apparatus provided in the second sealed container. In the refrigeration cycle apparatus according to any one of claims 1 to 9,
A refrigeration cycle apparatus filled with carbon dioxide as a refrigerant.

Images