JP2009085189A - Displacement type expander, expander-integrated compressor, and refrigeration cycle equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide refrigeration cycle equipment of a power recovery type capable of efficiently recovering expansion energy of a working fluid. <P>SOLUTION: The displacement type expander of a power recovery type includes: an intake port for sucking a working fluid; a working chamber for expanding the working fluid sucked from the intake port by changing a volume of the working fluid; a discharge port for discharging the working fluid expanded in the working chamber; a flow rate varying mechanism for varying a flow rate of the working fluid passing through the working chamber; and an overexpansion preventing mechanism for preventing the working fluid from overexpanding in the working chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a positive displacement expander, an expander-integrated compressor, and a refrigeration cycle apparatus.

  There has been proposed a power recovery type refrigeration cycle apparatus that utilizes expansion energy of a working fluid recovered by an expander to compress the working fluid by a compressor. As such a refrigeration cycle apparatus, a refrigeration cycle apparatus using an expander-integrated compressor in which an expander and a compressor are connected by a rotating shaft is known (for example, see Patent Document 1).

  In general, a refrigeration cycle apparatus using an expander-integrated compressor includes a refrigerant circuit that sequentially connects a compressor, a radiator, an expander, and an evaporator. An electric motor that rotationally drives the rotary shaft is provided between the compressor and the expander connected by the rotary shaft.

  The working fluid circulating through the refrigeration cycle apparatus is compressed by the compressor, thereby changing from the medium temperature and low pressure state to the high temperature and high pressure state, and then cooled to the medium temperature and high pressure state by the radiator. And it expands in an expander, and after changing to a low temperature low pressure state, it is heated with an evaporator, returns to a medium temperature low pressure state, is again suck | inhaled by a compressor, and repeats the said circulation.

  In the expander, the expansion energy of the working fluid is recovered and converted into rotational energy for rotating the rotating shaft. This rotational energy is also used as a part of driving energy for driving the compressor, and as a result, the power of the electric motor is reduced.

  The volume of the compression chamber immediately after the compression chamber is shut off from the inflow side in the compressor is Vcs, the volume of the expansion chamber immediately after the expansion chamber is shut off from the inflow side in the expander is Ves, and the rotation speed of the rotating shaft is N. Then, the volume flow rate of the working fluid sucked into the compressor is Vcs × N, and the volume flow rate of the working fluid sucked into the expander is Ves × N. That is, unless the volume of the compression chamber and the volume of the working chamber are the same, the volume flow rate of the working fluid to the compressor and the volume flow rate of the working fluid to the expander are different.

  On the other hand, the mass flow rate in the compressor and the mass flow rate in the expander are equal. Therefore, if this mass flow rate is G, the density of the working fluid sucked into the compressor is G / (Vcs × N), and the density of the working fluid sucked into the expander is G / (Ves × N).

  From these equations, the density ratio between the working fluid sucked into the compressor and the working fluid sucked into the expander is {G / (Vcs × N)} / {G / (Ves × N)}, that is, It becomes Ves / Vcs and is restricted to a constant value.

  When the density ratio between the working fluid sucked into the compressor and the working fluid sucked into the expander is restricted to a constant value as in the refrigeration cycle apparatus, free control of the refrigeration cycle apparatus is hindered. Specifically, in the refrigeration cycle apparatus, at a predetermined heat source temperature, the high-pressure side pressure (the pressure of the working fluid until it is discharged from the compressor and sucked into the expander) is the optimum pressure (coefficient of performance COP). Pressure). On the other hand, the high-pressure side pressure and the low-pressure side pressure of the refrigeration cycle device (the pressure of the working fluid until it is discharged from the expander and sucked into the compressor) changes depending on the operating conditions such as the temperature change of the cooling target and the heat dissipation target. To do. The density ratio between the working fluid sucked into the compressor and the working fluid sucked into the expander also fluctuates in accordance with the operating conditions. However, in the refrigeration cycle apparatus, the density ratio is restricted to a constant value Ves / Vcs. Therefore, the temperature and pressure of the working fluid cannot be freely controlled. For this reason, in the conventional expander, when the operating condition deviates from a predetermined one, the expander is in a so-called overexpansion or underexpansion state, and the expansion energy of the working fluid cannot be efficiently recovered in the expander.

In view of this, there has been proposed an expander that can change the volume of the expansion chamber itself by providing an expansion chamber in the expansion chamber of the expander and changing the volume of the auxiliary chamber according to the operating conditions. (For example, refer to Patent Document 2). In the above expander, the expansion energy of the working fluid can be efficiently recovered in the expander by changing the volume of the expansion chamber according to the operating conditions.
JP 2001-116371 A JP 2006-46257 A

  In the expander as described above, the volume of the working fluid sucked into the expander is not affected by changing the volume of the auxiliary chamber without affecting the volume flow rate Ved × N of the working fluid discharged from the expander. The flow rate Ves × N can be changed.

  However, if the volume flow rate Ves × N of the working fluid sucked into the expander is changed by changing the volume of the auxiliary chamber, the expansion ratio Ved × N / Ves × N of the working fluid in the expander, that is, Ved / Ves also changes. For example, if the volumetric flow rate Ves × N of the working fluid sucked into the expander is reduced, the volumetric flow rate Ved × N of the working fluid discharged from the expander is always constant, so the expansion ratio Ved / Ves increases. As a result, the discharge pressure Ped of the expanded working fluid inside the expander becomes low.

As a result, even in the conventional expander that can change the volume of the expansion chamber as described above, the discharge pressure Ped of the expanded working fluid inside the expander is higher than the low-pressure side pressure P _Low in the refrigeration cycle apparatus. This causes an overexpansion phenomenon in which the expansion of the working fluid cannot be efficiently recovered.

  The present invention has been made in view of such points, and an object of the present invention is to efficiently recover expansion energy of a working fluid in a power recovery type refrigeration cycle apparatus.

  The positive displacement expander according to the present invention includes a suction port for sucking a working fluid, a working chamber for expanding the working fluid sucked from the suction port by changing the volume, and a working fluid expanded in the working chamber. A discharge port for discharging the fluid, a flow rate variable mechanism for changing the flow rate of the working fluid passing through the working chamber, and an overexpansion preventing mechanism for preventing overexpansion in the working chamber.

  According to the present invention, in the power recovery type refrigeration cycle apparatus, it is possible to efficiently recover the expansion energy of the working fluid.

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

(Embodiment 1)
FIG. 1 is a configuration diagram of a refrigeration cycle apparatus 200 according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view of the expander-integrated compressor 201 according to Embodiment 1 of the present invention. 3A is a cross-sectional view of the expander-integrated compressor 201 taken along line BB in FIG. 2, and FIG. 3B is a view of the expander-integrated compressor 201 taken along line AA in FIG. It is a cross-sectional view.

  As shown in FIG. 1, the refrigeration cycle apparatus 200 according to the first embodiment is configured by connecting an expander-integrated compressor 201, a radiator 202, and an evaporator 203 by a pipe 205. .

  The expander-integrated compressor 201 has a compression mechanism 2, an electric motor 3, and an expansion mechanism 4 arranged in order from the top inside the hermetic container 1 and connected by a shaft 5. 6, and operates by receiving power supply from the power source 204. Further, the expander-integrated compressor 201 is provided with a suction pipe 8, a discharge pipe 9, a discharge pipe 11, and a suction pipe 12 through the sealed container 1.

  Carbon dioxide is used as the working fluid that circulates in the refrigeration cycle apparatus 200 according to the first embodiment. The working fluid is sucked into the compression mechanism 2 from the suction pipe 8 and compressed, and is discharged into the internal space of the sealed container 1. The working fluid discharged into the internal space of the sealed container 1 is discharged from the discharge pipe 9 and guided to the radiator 202. The working fluid radiated to the heat source by the radiator 202 is sucked into the expansion mechanism 4 from the suction pipe 12 and expanded. At this time, the expansion energy of the working fluid is collected by the expansion mechanism 4 and superimposed on the power of the electric motor 3 that drives the compression mechanism 2. The working fluid expanded by the expansion mechanism 4 is discharged from the discharge pipe 11 and guided to the evaporator 203. The working fluid that has absorbed heat from the heat source in the evaporator 203 returns to the compression mechanism 2 from the suction pipe 8 again.

  Hereinafter, the configuration of the expander-integrated compressor 201 according to the first embodiment will be described in detail.

  As shown in FIG. 2, the compression mechanism 2 according to the first embodiment is a so-called scroll type compression mechanism including a main bearing member 15, a fixed scroll 16, a turning scroll 17, and a rotation restricting mechanism 18.

  The main bearing member 15 is fixed to the inner wall of the sealed container 1 by welding or shrink fitting, and supports the upper end portion of the shaft 5. A fixed scroll 16 is bolted to the upper surface of the main bearing member 15, and a muffler 39 is provided on the upper end surface of the fixed scroll 16.

  The fixed scroll 16 is formed with a suction hole 16 a and a discharge hole 16 b, and the suction hole 16 a communicates with the suction pipe 8. A reed valve 36 is provided on the upper end surface of the discharge hole 16b. An orbiting scroll 17 is engaged with the lower surface of the fixed scroll 16. Thereby, a compression chamber 35 is formed between the fixed scroll 16 and the orbiting scroll 17.

  A rotation restricting mechanism 18 such as an Oldham ring is provided between the orbiting scroll 17 and the main bearing member 15 to prevent the orbiting scroll 17 from rotating and to guide the circular orbit movement. The orbiting scroll 17 is engaged with a first eccentric portion 5 a formed at the upper end of the shaft 5, thereby performing circular orbit movement by eccentric driving.

  The working fluid sucked from the suction pipe 8 through the suction hole 16 a is compressed by the compression chamber 35 moving from the outer edge portion to the center portion with the eccentric drive of the shaft 5. The compressed working fluid pushes up the reed valve 36, is discharged to the inner space of the muffler 39 through the discharge hole 16 b of the fixed scroll 16, and is discharged to the inner space of the sealed container 1.

  The electric motor 3 includes a stator 19 fixed to the hermetic container 1 and a rotor 20 fixed to the shaft 5. The terminal 14 is disposed through the upper part of the hermetic container 1, and supplies power from the power source 204 to the electric motor 3.

  As shown in FIGS. 2 and 3, the expansion mechanism 4 according to the first embodiment includes an upper bearing member 21, a first cylinder 22, an intermediate plate 23, a second cylinder 24, a lower bearing member 25, a first roller 26 ( 1st piston), 2nd roller 27 (2nd piston), 1st vane 28, 2nd vane 29, the 1st spring 30, and the 2nd spring 31 are what is called a two-stage rotary type expansion mechanism, and , A variable flow rate mechanism 80 and an overexpansion prevention mechanism 90 are provided.

  The upper bearing member 21 is fixed to the inner wall of the sealed container 1 by welding, shrink fitting, or the like, and supports the shaft 5 rotatably. The upper bearing member 21 is formed with a discharge port 21 a that communicates with the discharge pipe 11 and a suction port 21 b that communicates with the suction pipe 12. Further, in the vicinity of the outer edge of the upper bearing member 21, a notch 21d penetrating vertically is formed. A second cylinder 24 and a first cylinder 22 are sequentially fixed to the lower surface of the upper bearing member 21 via an intermediate plate 23.

  A first roller 26 and a second roller 27 are disposed in the internal space of the first cylinder 22 and the second cylinder 24, respectively. The first roller 26 and the second roller 27 are rotatably fitted to the second eccentric portion 5b and the third eccentric portion 5c of the shaft 5, respectively. The axial heights of the first cylinder 22 and the first roller 26 are set to be lower than the axial heights of the second cylinder 24 and the second roller 27.

  A vane groove 22a and a vane groove 24a are formed in the first cylinder 22 and the second cylinder 24, respectively. A first vane 28 and a second vane 29 are slidably disposed in the vane groove 22a and the vane groove 24a, respectively. A first spring 30 and a second spring 31 are installed on the back surfaces of the first vane 28 and the second vane 29, respectively. As a result, the first vane 28 and the second vane 29 are pressed against the first roller 26 and the second roller 27, respectively.

  A lower bearing member 25 is fixed to the lower surface of the first cylinder 22 and rotatably supports the shaft 5. The lower bearing member 25 is formed with a suction hole 25a and a passage space 25b. A sealing plate 32 is fixed to the lower end surface of the lower bearing member 25.

  The expansion mechanism 4 is immersed in an oil reservoir 6 provided at the bottom of the sealed container 1. An oil pump 34 is installed at the lower end of the sealing plate 32. The oil in the oil reservoir 6 is supplied to the first eccentric part 5a, the second eccentric part 5b, and the third eccentric part 5c via an oil supply path 5d provided in the shaft 5, and the compression mechanism 2 and the expansion mechanism. 4 and lubricate. Since the oil after lubrication has a density higher than that of the working fluid, the oil drops down inside the sealed container 1 by gravity and returns to the oil reservoir 6 again. At this time, the oil that has lubricated the compression mechanism 2 returns to the oil reservoir 6 through the notch 21 d of the upper bearing member 21. Similarly, the oil contained in the working fluid discharged from the compression mechanism 2 is also separated in the process of flowing inside the sealed container 1 and returns to the oil reservoir 6 through the notch 21d of the upper bearing member 21. .

  Inside the expansion mechanism 4, a first working chamber 37 is formed by the first cylinder 22, the middle plate 23, the first roller 26, and the lower bearing member 25. The first working chamber 37 is partitioned by the first vane 28 into a first suction space 37a and a first discharge space 37b. Similarly, a second working chamber 38 is formed by the second cylinder 24, the intermediate plate 23, the second roller 27, and the upper bearing member 21. The second working chamber 38 is partitioned by the second vane 29 into a second suction space 38a and a second discharge space 38b.

  A communication hole 23 a penetrating vertically is formed in the intermediate plate 23, and the first discharge space 37 b of the first working chamber 37 and the second suction space 38 a of the second working chamber 38 communicate with each other. Thereby, an expansion chamber in which the working fluid expands is formed.

  The second cylinder 24, the intermediate plate 23, and the first cylinder 22 are formed with through passages 24 b, 23 b, 22 b to form one flow passage, and the upper end communicates with the suction port 21 b of the upper bearing member 21. The lower end communicates with the passage space 25b.

  The working fluid sucked from the suction pipe 12 through the suction port 21b of the upper bearing member 21 sequentially passes through the series of through passages 24b, 23b, 22b, the passage space 25b of the lower bearing member 25, and the suction hole 25a. Inhaled into one working chamber 37. The working fluid expanded by the expansion mechanism 4 is discharged from the discharge pipe 11 through the discharge port 21 a of the upper bearing member 21.

  The variable flow rate mechanism 80 according to the first embodiment includes an auxiliary chamber 81, a piston 84, a pipe 85, a back pressure control valve 86, and a control device 87. The auxiliary chamber 81 is provided in the first cylinder 22 and is partitioned into a back pressure chamber 82 and a variable volume chamber 83 by a piston 84. The back pressure chamber 82 is connected to the pipe 205 on the inlet side of the expansion mechanism 4 by a pipe 85 having a back pressure control valve 86 provided through the sealed container 1, and the operation discharged from the radiator 202. A portion of the fluid can be enclosed. The pressure of the working fluid sealed in the back pressure chamber 82 is controlled by a control device 87 connected to the back pressure control valve 86. The variable volume chamber 83 communicates with the first working chamber 37.

  With the above configuration, the pressure in the first working chamber 37 acts on the end surface of the piston 84 on the variable volume chamber 83 side, that is, the first working chamber 37 side, and the end surface of the piston 84 on the back pressure chamber 82 side acts on the end surface. The pressure in the back pressure chamber 82 acts. Thus, the position of the piston 84 in the auxiliary chamber 81 is determined by the balance of the pressure.

  For example, when the pressure in the first working chamber 37 is larger than the pressure in the back pressure chamber 82, the piston 84 moves in the direction toward the back pressure chamber 82 (hereinafter referred to as the rear). On the other hand, when the pressure in the first working chamber 37 is smaller than the pressure in the back pressure chamber 82, the piston 84 moves in the direction toward the variable volume chamber 83 (hereinafter referred to as the front). The piston 84 stops when it reaches the front end portion of the auxiliary chamber 81 or the rear end portion of the auxiliary chamber 81. However, when the pressure in the first working chamber 37 and the pressure in the back pressure chamber 82 are balanced, the auxiliary pressure is reduced. Even if the front and rear ends of the chamber 81 are not reached, the chamber 81 stops at that time.

  Therefore, in the expansion mechanism 4 in the first embodiment, the volume of the variable volume chamber 83 can be changed by adjusting the pressure in the back pressure chamber 82 by the control device 87, that is, the first working chamber 37. The suction volume and the discharge volume can be changed.

  As the overexpansion prevention mechanism 90 in the first embodiment, a check valve 90a is used, and the check valve 90a is provided in the opening on the second cylinder 24 side of the discharge port 21a formed in the upper bearing member 21. It has been.

  FIG. 4 is an operation principle diagram of the expansion mechanism 4 according to Embodiment 1 of the present invention. The operation of the expansion mechanism 4 in the first embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 4A, when the first roller 26 rotates counterclockwise and the suction hole 25a is opened, the working fluid starts to be sucked into the first suction space 37a of the first working chamber 37. As shown in FIGS. 4B and 4C, the working fluid is further sucked into the first suction space 37a as the first roller 26 rotates. Then, as shown in FIG. 4 (d), the first roller 26 further rotates to start closing the suction hole 25a, and at the same time the suction hole 25a is completely closed, suction into the first suction space 37a is performed. Complete.

  When the suction of the working fluid is completed, the first suction space 37a moves to the first discharge space 37b and communicates with the second suction space 38a of the second working chamber 38 through the communication hole 23a. And the expansion mechanism 4 repeats operation | movement of Fig.4 (a)-(d) again.

  As shown in FIGS. 4A, 4B, and 4C, the working fluid in the first discharge space 37b moves to the second suction space 38a as the first roller 26 rotates. The expansion of the working fluid occurs in the process of moving the working fluid from the first discharge space 37b to the second suction space 38a. As shown in FIG. 4D, the first roller 26 completely closes the communication hole 23a, and at the same time, the movement to the second suction space 38a is completed, and the expansion of the working fluid is also completed.

  Simultaneously with the expansion of the working fluid, the second suction space 38a moves to the second discharge space 38b. And the expansion mechanism 4 repeats operation | movement of Fig.4 (a)-(d) again.

  As shown in FIG. 4A, when the second roller 27 rotates counterclockwise and the discharge port 21a opens, the expanded working fluid in the second discharge space 38b starts to be discharged. As shown in FIGS. 4B and 4C, the working fluid is further discharged as the second roller 27 rotates. Then, as shown in FIG. 4 (d), the second roller 27 further rotates to start closing the discharge port 21a, and at the same time the discharge port 21a is completely closed, the discharge from the second discharge space 38b is performed. Complete.

  In the expansion process, the piston 84 in the auxiliary chamber 81 moves to the first discharge space 37b side. In FIG. 4B, where the working fluid has expanded to a low pressure, the front end of the auxiliary chamber 81, that is, the first discharge space 37b is faced, and the variable volume chamber 83 (volume v ') disappears. In FIG. 4C, the auxiliary chamber 81 communicates with the first suction space 37a, and the piston 84 in the auxiliary chamber 81 moves rearward due to the pressure relationship between the back pressure chamber 82 and the first suction space 37a. As a result, a variable volume chamber 83 (volume v ′) is generated in the auxiliary chamber 81, and the working fluid sucked into the first suction space 37 a flows into the variable volume chamber 83.

  As a result, the expansion mechanism 4 having the flow rate variable mechanism 80 according to the first embodiment allows the working fluid sucked into the first suction space 37a to flow into and out of the variable volume chamber 83, whereby the first suction space. The volume of the working fluid sucked into 37a can be varied. That is, in the first embodiment, the ratio of the volume Ved of the variable volume chamber 83 to the volume Ves of the first working chamber 37 and the volume Ved of the second working chamber 38 is the expansion ratio Ved / ( Ves + v ′).

In the above discharge process, when the expansion is completed, the discharge pressure Ped of the working fluid in the second discharge space 38b is the pressure in the pipe 205 on the outlet side of the expansion mechanism 4, that is, the low pressure side pressure P in the refrigeration cycle apparatus. If it is lower than _Low, the check valve 90a provided at the opening on the second cylinder 24 side of the discharge port 21a remains closed, and the working fluid is not discharged from the expansion mechanism 4. Therefore, in the second discharge space 38b, the working fluid is recompressed until the discharge pressure Ped of the working fluid in the second discharge space 38b becomes equal to the low-pressure side pressure P _Low in the refrigeration cycle apparatus, and is over-expanded. Loss due to outflow of the working fluid can be prevented.

(Embodiment 2)
FIG. 5A is a cross-sectional view taken along line B-B of the expander-integrated compressor 301 using the injection type variable flow rate mechanism 100 according to Embodiment 2 of the present invention, and FIG. It is a cross-sectional view in the AA line of the expander integrated compressor 301 using the injection type flow variable mechanism 100 in Embodiment 2 of invention. In addition, the said BB line and AA line show the same location as the BB line and AA line of the expander integrated compressor 201 of FIG. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5 (b), the flow rate variable mechanism 100 according to the second embodiment includes an injection line 101, a flow rate control valve 102, a control device 103, an injection line passage 106, and an injection valve 107. The difference from the first embodiment is that it is a so-called injection type in which the amount of working fluid flowing into the first suction space 37a is controlled by the flow control valve 102 and the control device 103.

  The injection line 101 penetrates the sealed container 1 and is connected to an injection line passage 106 provided in the first cylinder 22 and a pipe 205 on the inlet side of the expansion mechanism 4. Thereby, a part of the working fluid discharged from the radiator 202 can be caused to flow into the first suction space 37a into the injection line 101. The injection line 101 is provided with a flow control valve 102 to which a control device 103 is connected, and the amount of working fluid flowing into the injection line 101 is controlled by the control device 103. An injection valve 107 is provided at the opening on the first cylinder 22 side of the injection line passage 106 to partition the injection line passage 106 and the first working chamber 37.

  Even when such an injection type variable flow rate mechanism 100 is used, as in the first embodiment, overexpansion can be avoided and energy can be efficiently recovered from the working fluid.

(Embodiment 3)
6A is a cross-sectional view taken along line BB of the expander-integrated compressor 401 according to Embodiment 3 of the present invention, and FIG. 6B is an expander according to Embodiment 3 of the present invention. It is a cross-sectional view in the AA line of the body compressor 401. In addition, the said BB line and AA line show the same location as the BB line and AA line of the expander integrated compressor 201 of FIG. In the third embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6A, the over-expansion preventing mechanism 110 of the third embodiment is configured by a differential pressure valve 111, a discharge working fluid passage 112, and a discharge working fluid line 113. 2 and different.

  The discharge working fluid line 113 penetrates the sealed container 1 and is connected to a discharge working fluid passage 112 provided in the second cylinder 24 and a pipe 205 on the outlet side of the expansion mechanism 4. As a result, a part of the working fluid discharged from the expansion mechanism 4 can flow into the discharge working fluid line 113. A differential pressure valve 111 is provided in the opening of the discharge working fluid passage 112 on the second cylinder 24 side, and partitions the discharge working fluid passage 112 and the second discharge space 38b.

With such a configuration, when the discharge pressure Ped of the working fluid in the second discharge space 38b becomes lower than the low-pressure side pressure P _Low in the refrigeration cycle apparatus during the expansion process, the differential pressure valve 111 is opened. The working fluid discharged from the expansion mechanism 4 is guided to the second discharge space 38b, and the working fluid is discharged until the discharge pressure Ped of the working fluid in the second discharge space 38b becomes higher than the low-pressure side pressure P _Low in the refrigeration cycle apparatus. Recompress.

  Therefore, even when the overexpansion prevention mechanism 110 is used, as in the first and second embodiments, it is possible to prevent a decrease in the discharge pressure Ped of the working fluid in the second discharge space 38b and to avoid overexpansion. Energy can be recovered efficiently. Further, by using the differential pressure valve 111, there is nothing that obstructs the flow of the working fluid in the discharge port 21a, and a smooth discharge process can be realized, so that energy can be recovered more efficiently.

(Embodiment 4)
FIG. 7 (a) is a cross-sectional view taken along line BB of the expander-integrated compressor 501 according to the fourth embodiment of the present invention, and FIG. 7 (b) is an expander according to the fourth embodiment of the present invention. It is a cross-sectional view in the AA line of the body-type compressor 501. FIG. 8 is a configuration diagram of a refrigeration cycle apparatus 500 according to Embodiment 4 of the present invention. In addition, the said BB line and AA line show the same location as the BB line and AA line of the expander integrated compressor 201 of FIG. In the fourth embodiment, the same parts as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 7A, 7 </ b> B, and 8, in the fourth embodiment, the working fluid passages of the overexpansion prevention mechanism and the flow rate variable mechanism are made common and provided in the first cylinder 22. The difference from the third embodiment is that both functions are realized by one differential pressure valve.

  The flow rate variable mechanism and the overexpansion prevention mechanism according to the fourth embodiment include an injection line 101, a flow rate control valve 102, a control device 103, an expander discharge working fluid valve 104, an overexpansion control device 105, an injection line passage 106, and an injection. The valve 107 is configured.

  One end of the injection line 101 penetrates the sealed container 1 and is connected to the injection line passage 106 provided in the first cylinder 22, and the other end branches to connect the pipe 205 and the expansion mechanism 4 on the inlet side of the expansion mechanism 4. Each is connected to the outlet side pipe 205.

  The injection line 101a connected to the pipe 205 on the inlet side of the expansion mechanism 4 is provided with a flow control valve 102 to which the control device 103 is connected. The injection line 101b connected to the piping 205 on the outlet side of the expansion mechanism 4 is provided with an expander discharge working fluid valve 104 to which an overexpansion control device 105 is connected. An injection valve 107 is provided in the opening portion on the first cylinder 22 side of the injection line passage 106, and partitions the injection line passage 106 and the first working chamber 37.

  With such a configuration, the flow control valve 102 is opened at the start of expansion, and a part of the working fluid discharged from the radiator 202 is guided to the first working chamber 37, so that the inside of the first working chamber 37 The flow rate of the working fluid can be varied. After introducing sufficient working fluid to the first working chamber 37, the flow rate control valve 102 is closed, and the expander discharge working fluid valve 104 is opened by the action of the overexpansion control device 105, whereby the injection line passage 106. By guiding the working fluid discharged from the expansion mechanism 4, the injection valve 107 can also function as an overexpansion prevention valve. Thereby, it is not necessary to separately provide the variable flow rate mechanism and the overexpansion prevention mechanism, and the number of parts and the processing cost can be reduced, so that the present invention can be realized at low cost.

  Therefore, even when the working fluid passages of the variable flow rate mechanism and the overexpansion prevention mechanism are made common and both functions are shared by a single differential pressure valve, overexpansion can be avoided and the operation can be avoided as in the third embodiment. Energy can be efficiently recovered from the fluid.

  In the first to fourth embodiments, the electric motor 3 is disposed between the compression mechanism 2 and the expansion mechanism 4, but the present invention is not limited to this. The electric motor 3 is disposed outside the sealed container, and the compressor mechanism 2 and the expansion mechanism 4 are disposed in the same sealed container. For example, the compression mechanism 2 is driven only by the recovery power of the expansion mechanism 4. The present invention can also be applied to a simple apparatus.

  In addition, the compression mechanism 2 and the expansion mechanism 4 are arranged inside the sealed container 1 with the longitudinal direction being the vertical direction, but the present invention is not limited to this, and the compression mechanism 2 takes the longitudinal direction in the horizontal direction or the oblique direction. Even if the expansion mechanism 4 is arranged, the present invention can be applied.

  Moreover, although the expander-integrated compressor is used as an example, the present invention can be applied to a separate expander.

  In addition, although a rolling piston type expander using two cylinders is described, if it is a positive displacement expander such as a single cylinder type rolling piston type expander, a scroll type expander, a sliding vane type expander, The present invention can be applied regardless of the form of the mechanism.

  The present invention is useful for a positive displacement expander, an expander-integrated compressor, and a refrigeration cycle apparatus.

Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention The longitudinal cross-sectional view of the expander integrated compressor in Embodiment 1 of this invention (A) Cross-sectional view of the expander-integrated compressor taken along line BB in FIG. 2 (b) Cross-sectional view of the expander-integrated compressor taken along line A-A in FIG. Operational principle diagram of expansion mechanism in Embodiment 1 of the present invention (A) Cross-sectional view taken along line BB of the expander-integrated compressor according to Embodiment 2 of the present invention (b) Cross section taken along line AA of the expander-integrated compressor according to Embodiment 2 of the present invention Area (A) Cross-sectional view taken along line BB of the expander-integrated compressor according to Embodiment 3 of the present invention (b) Crossing taken along line AA of the expander-integrated compressor according to Embodiment 3 of the present invention Area (A) Cross-sectional view taken along line BB of the expander-integrated compressor according to Embodiment 4 of the present invention (b) Crossing along line AA of the expander-integrated compressor according to Embodiment 4 of the present invention Area Configuration diagram of refrigeration cycle apparatus in Embodiment 4 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compression mechanism 3 Electric motor 4 Expansion mechanism 5 Shaft 5a 1st eccentric part 5b 2nd eccentric part 5c 3rd eccentric part 5d Oil supply path 6 Oil storage part 8 Intake pipe 9 Discharge pipe 11 Discharge pipe 12 Intake pipe 14 Terminal 15 Main bearing member 16 Fixed scroll 16a Suction hole 16b Discharge hole 17 Orbiting scroll 18 Rotation restricting mechanism 19 Stator 20 Rotor 21 Upper bearing member 21a Discharge port 21b Suction port 21d Notch 22 First cylinder 22a, 24a Vane groove 22b, 23b 24b Through passage 23 Middle plate 23a Communication hole 24 Second cylinder 25 Lower bearing member 25a Suction hole 25b Passage space 26 First roller 27 Second roller 28 First vane 29 Second vane 30 First spring 31 Second spring 32 Sealed Plate 34 Oil pump 35 Compression 36 Reed valve 37 First working chamber 37a First suction space 37b First discharge space 38 Second working chamber 38a Second suction space 38b Second discharge space 39 Muffler 80 Flow rate variable mechanism 81 Auxiliary chamber 82 Back pressure chamber 83 Variable volume chamber 84 Piston 85 Piping 86 Flow control valve 87 Control device 90 Over-expansion prevention mechanism 90a Check valve 100 Flow rate variable mechanism 101, 101a, 101b Injection line 102 Flow control valve 103 Control device 104 Expander discharge working fluid valve 105 Over-expansion control device 106 Injection line passage 107 Injection valve 110 Over-expansion prevention mechanism 111 Differential pressure valve 112 Discharge working fluid passage 113 Discharge working fluid line 200,500 Refrigeration cycle apparatus 201, 301, 401, 501 Expander-integrated compressor 202 Heat radiator 03 evaporator 204 power 205 pipe

Claims (7)

A suction port for sucking the working fluid;
A working chamber for expanding the working fluid sucked from the suction port by changing its volume;
A discharge port for discharging the working fluid expanded in the working chamber;
A flow rate variable mechanism for varying the flow rate of the working fluid passing through the working chamber;
An overexpansion preventing mechanism for preventing overexpansion in the working chamber;
A positive displacement expander characterized by comprising: 2. The positive displacement type according to claim 1, wherein the overexpansion prevention mechanism is a check valve provided in a discharge port of the working chamber, and the overexpansion is eliminated by recompressing the overexpanded working fluid. Expansion machine. The over-expansion prevention mechanism includes a communication passage that communicates the working chamber and a pipe on the outlet side of the expander, and a differential pressure valve that is provided in the communication passage and opens when the pressure in the working chamber is lower than a discharge pressure. The positive displacement expander according to claim 1, comprising: An expansion mechanism comprising the positive displacement expander according to any one of claims 1 to 3,
A compression mechanism for compressing the working fluid;
A rotating shaft connecting the expansion mechanism and the compression mechanism;
An expander-integrated compressor equipped with a compressor. A refrigeration cycle apparatus in which a compressor, a radiator, and the positive displacement expander according to any one of claims 1 to 3 and an evaporator are sequentially connected in an annular shape. The refrigeration cycle apparatus according to claim 5, wherein the working fluid is carbon dioxide. A suction port for sucking the working fluid; a working chamber for expanding the working fluid sucked from the suction port when the volume changes; a discharge port for discharging the working fluid expanded in the working chamber; and the suction port An expansion mechanism having an inlet side pipe and a discharge side pipe connected to the discharge port;
An injection passage for communicating the inlet-side piping and the working chamber;
An injection valve provided in the injection passage for controlling the flow rate of the working fluid in the injection passage;
A discharge working fluid passage for communicating the outlet-side pipe and the working chamber;
A differential pressure valve provided in the discharge working fluid passage for controlling the flow of the working fluid in the discharge working fluid passage;
A positive displacement expander.

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