JP2013019336A - Expander and refrigerating device - Google Patents

Abstract

A sub-intake passage switching mechanism is simplified to reduce the number of parts and to save space.
An expander (40) advances in the rotational direction of a piston (51) from an opening position of a main suction passage (46) of the expansion chamber (52) and an expansion chamber (52) of the main suction passage (46). The auxiliary suction passage (70) of the expansion chamber (52) that opens to the position is provided. In the secondary suction passage (70), the secondary side chamber (88) into which the primary pressure of the primary side chamber (87) communicating with the secondary suction passage (70) and the refrigerant having a predetermined pressure in the refrigerant circuit (11) are introduced. A switching valve (80) that opens and closes the auxiliary suction passage (70) based on the pressure difference from the secondary side pressure and supplies and shuts off the high-pressure refrigerant to the expansion chamber (52) is provided. Further, the auxiliary suction passage (70) is located upstream of the switching valve (80), and opens and closes the auxiliary suction passage (70) so that the switching valve (80) opens and closes the auxiliary suction passage (70). A control valve (75) is provided.
[Selection] Figure 5

Description

    The present invention relates to an expander and a refrigeration apparatus including the expander, and particularly relates to measures for controlling the suction volume of the expander.

    Conventionally, as shown in Patent Document 1, there is a refrigeration apparatus in which an expander is connected to a refrigerant circuit and the power of the refrigerant is recovered in the expander. This refrigeration apparatus recovers power from high-pressure refrigerant in an expander and uses this power for driving a compressor.

    By the way, since the refrigerant circuit of the refrigeration apparatus is a closed circuit, the circulation amount of the refrigerant passing through the compressor per unit time (corresponding to mass flow rate, the same applies hereinafter) and the circulation amount of the refrigerant passing through the expander are Must always match.

    However, when an expander is designed at a certain design specification point, for example, a heating rating, if it is operated under conditions that deviate from the design specification point, the amount of circulation between the compressor and the amount of circulation at the expander Excess or deficiency occurs. Specifically, for example, when the circulation rate between the compressor and the expander is matched at the time of heating rating, the optimal expansion machine suction volume is the heating rating at the cooling rating when the suction pressure of the compressor increases. Since it becomes larger than the case of time, the refrigerant of the expander is insufficient and overexpansion occurs.

    In view of this, the expander of the refrigeration apparatus of Patent Document 1 described above has a sub-suction passage having a switching valve, which is a switching mechanism, formed in the cylinder separately from the main suction passage. The auxiliary suction passage has one end connected to the main suction passage and the other end opened to a position advanced in the rotation direction of the piston from the opening position of the expansion chamber of the main suction passage. Supply.

    The expander opens, for example, the switching valve and the high-pressure refrigerant is introduced into the expansion chamber through the auxiliary suction passage under an operating condition in which the suction pressure of the compressor increases. As a result, the pressure of the refrigerant on the outflow side of the expander approaches the suction pressure of the compressor, and the occurrence of overexpansion is prevented.

JP 2009-228568 A

    However, the above-described switching valve of the expander uses the high-pressure refrigerant pressure on the inlet side of the expander and the low-pressure refrigerant pressure on the outlet side of the expander as the secondary side pressure that is the back pressure of the valve body. Since the refrigerant pressure and the low-pressure refrigerant pressure are switched and opened and closed, there are problems such as a large number of parts.

    In other words, the switching valve needs to be connected to a high-pressure side back pressure passage that guides the high-pressure refrigerant and a low-pressure side back pressure passage that guides the low-pressure refrigerant, and opens and closes the high-pressure side back pressure passage and the low-pressure side back pressure passage. It is necessary to provide a high-pressure side control valve and a low-pressure side control valve. Therefore, since the conventional expander needs to provide two back pressure passages and two control valves, there is a problem that the number of parts is increased and the cost is high, and a space for installing the control valve is required. There was a problem of requiring a large space.

    The present invention has been made in view of such a point, and an object thereof is to simplify the switching mechanism of the auxiliary suction passage, to reduce the number of parts, and to save space.

    1st invention is an expander which expands the high-pressure refrigerant | coolant of a refrigerant circuit (11) in an expansion chamber (52) by rotation of a rotating member (51), and collects the motive power of a refrigerant | coolant.

    The first invention provides a main suction passage (46) for supplying high-pressure refrigerant to the expansion chamber (52), and a rotating member (51) from the opening position of the expansion chamber (52) of the main suction passage (46). The auxiliary suction passage (70) for supplying high-pressure refrigerant to the expansion chamber (52) and the auxiliary suction passage (70) are provided in the auxiliary suction passage (70). The secondary suction is based on the differential pressure between the primary side pressure of the communicating primary side chamber (87) and the secondary side pressure of the secondary side chamber (88) into which the refrigerant of a predetermined pressure in the refrigerant circuit (11) is introduced. A switching valve (80) that opens and closes the passage (70) and supplies and shuts off the high-pressure refrigerant to the expansion chamber (52), and is provided in the auxiliary suction passage (70), upstream of the switching valve (80). And a control valve (75) that opens and closes the auxiliary suction passage (70) so that the switching valve (80) opens and closes the auxiliary suction passage (70). It is characterized in that.

    In the first aspect of the invention, when the control valve (75) closes the auxiliary suction passage (70), the switching valve (80) shuts off the supply of high-pressure refrigerant from the auxiliary suction passage (70) to the expansion chamber (52). To do. As a result, the high-pressure refrigerant is supplied to the expansion chamber (52) only from the main suction passage (46). On the other hand, when the control valve (75) opens the auxiliary suction passage (70), the switching valve (80) allows the supply of high-pressure refrigerant from the auxiliary suction passage (70) to the expansion chamber (52). As a result, high-pressure refrigerant is supplied from both the main suction passage (46) and the sub suction passage (70) to the expansion chamber (52).

    As described above, since the closing points of the main suction passage (46) and the sub suction passage (70) are different, the expansion ratio is adjusted, the refrigerant circulation amount between the compressor and the expander is balanced, and overexpansion occurs. Is prevented.

    In a second aspect based on the first aspect, the switching valve (80) is connected to a back pressure passage (71) for guiding the high-pressure refrigerant in the refrigerant circuit (11) to the secondary chamber (88). It is characterized by.

    In the second aspect of the invention, the high-pressure refrigerant is introduced into the secondary chamber (88) of the switching valve (80), and the switching valve (80) is switched by the differential pressure between the primary pressure and the secondary pressure. .

    In a third aspect based on the first aspect, the switching valve (80) is connected to a back pressure passage (71) for guiding the low pressure refrigerant of the refrigerant circuit (11) to the secondary side chamber (88). It is characterized by.

    In the third aspect of the invention, the low-pressure refrigerant is introduced into the secondary chamber (88) of the switching valve (80), and the switching valve (80) is switched by the differential pressure between the primary pressure and the secondary pressure. .

    In a fourth aspect based on the second aspect, the switching valve (80) divides the valve chamber (81) into a primary side chamber (87) and a secondary side chamber (88), and the valve chamber (81 ) To open and close the high pressure outlet (85) communicating with the expansion chamber (52), and a biasing member for biasing the valve body (82) in the valve opening direction ( 83), and a secondary side consisting of a primary pressure obtained by applying a biasing force of the biasing member (83) to a refrigerant pressure in the primary chamber (87) and a high-pressure refrigerant pressure in the secondary chamber (88). The valve element (82) is configured to open and close the high-pressure outlet (85) by a pressure difference from the pressure.

    In the fourth aspect of the invention, when the high-pressure refrigerant is introduced into the primary side chamber (87), the urging force of the urging member (83) moves the valve body (82) in the valve opening direction, and the valve body (82 ) Opens the high pressure outlet (85). On the other hand, when the introduction of the high-pressure refrigerant to the primary side chamber (87) is blocked, the valve body (82) is moved in the valve closing direction by the high-pressure refrigerant pressure in the secondary side chamber (88), and the valve body (82) Closes the high pressure outlet (85).

    In a fifth aspect based on the third aspect, the switching valve (80) divides the valve chamber (81) into a primary side chamber (87) and a secondary side chamber (88), and the valve chamber (81 ) To open and close the high pressure outlet (85) communicating with the expansion chamber (52), and a biasing member for biasing the valve body (82) in the valve closing direction ( 83), and the secondary side obtained by applying the urging force of the urging member (83) to the primary side pressure composed of the refrigerant pressure in the primary side chamber (87) and the low pressure refrigerant pressure in the secondary side chamber (88) The valve element (82) is configured to open and close the high-pressure outlet (85) by a pressure difference from the pressure.

    In the fifth aspect, when high-pressure refrigerant is introduced into the primary side chamber (87), the high-pressure refrigerant pressure moves the valve body (82) in the valve opening direction, and the valve body (82) Open 85). On the other hand, when the introduction of the high-pressure refrigerant to the primary side chamber (87) is blocked, the valve body (82) is closed by the low-pressure refrigerant pressure in the secondary side chamber (88) and the urging force of the urging member (83). The valve body (82) moves in the valve direction and closes the high pressure outlet (85).

    The sixth invention is characterized in that, in any one of the first to fifth inventions, the back pressure passage (71) is formed in the expander body (43).

    In the sixth aspect of the invention, the refrigerant is introduced from the back pressure passage (71) formed in the expander body (43) into the secondary chamber (88) of the switching valve (80).

    7th invention is equipped with the expander (40) of any one of 1st-6th invention, The freezing apparatus characterized by the above-mentioned.

    In the seventh aspect of the invention, the refrigeration apparatus recovers power by the expander (40).

    According to the present invention, since the auxiliary suction passage (70) can be opened and closed by the switching valve (80) and the expansion ratio can be adjusted, the refrigerant circulation amount between the compressor (32) and the expander (40) is balanced. Can be made. As a result, for example, even if the operating conditions of the refrigeration apparatus change, it is possible to avoid the occurrence of overexpansion on the outflow side of the expander (40) and to suppress the generation of reverse torque. It is possible to improve the power recovery efficiency in 40) and to improve the mechanical reliability.

    Further, since the suction volume can be made variable by switching the switching valve (80), the expander operating area can be expanded.

    Further, since only one back pressure passage (71) of the switching valve (80) is formed, it is not necessary to form two back pressure passages as in the prior art, and the switching valve (80) Since only one control valve (75) for switching 80) is provided in the auxiliary suction passage (70), the number of parts can be reduced and the configuration can be simplified.

    Further, since the switching valve (80) is provided in the vicinity of the expansion chamber (52), the dead volume can be reduced. That is, when only the control valve (75) is provided in the auxiliary suction passage (70), the control valve (75) is provided in the auxiliary pipe connected to the refrigerant circuit (11). The space up to the expansion chamber (52) is the dead volume of the closed space that does not contribute to refrigerant expansion. In the present invention, since the switching valve (80) is provided in addition to the control valve (75), the switching valve (80) can be disposed in the vicinity of the expansion chamber (52), so that the dead volume is substantially eliminated. be able to. Thereby, for example, when a dead volume is formed, the power recovery amount (work amount) is reduced due to the dead volume, whereas in the present invention, the power recovery amount is not reduced. The desired power recovery efficiency can be obtained.

    Further, since the auxiliary suction passage (70) is switched by the switching valve (80), unlike the check valve, chattering at the time of suction can be prevented and the open state can be reliably maintained. Loss can be reduced and noise caused by vibration can be reduced.

    According to the sixth invention, since the back pressure passage (71) is formed in the expander body (43), the auxiliary suction passage (70) can be guided from the refrigerant circuit (11), A sufficient cross-sectional area of the suction passage (70) can be secured. As a result, the resistance of the auxiliary suction passage (70) can be reduced, so that the efficiency can be improved. Further, since the resistance of the auxiliary suction passage (70) can be reduced, the control range of the refrigerant flow rate can be increased, and the operation area can be further expanded.

    That is, conventionally, since the auxiliary suction passage is formed in the expander body, the formation of the auxiliary suction passage is restricted, and a sufficient cross-sectional area cannot be secured, and the pressure loss of the auxiliary suction passage is large. As a result, there is a problem that the performance is reduced and the operation area is reduced due to a reduction in the flow rate control width.

    On the other hand, according to the sixth invention, the auxiliary suction passage (70) can be guided from the refrigerant circuit (11), and the resistance of the auxiliary suction passage (70) can be reduced. The improvement can be achieved and the operation area can be expanded by expanding the flow rate control width.

1 is a schematic configuration diagram of a refrigerant circuit of an air-conditioning apparatus according to Embodiment 1. FIG. FIG. 2 is a longitudinal sectional view of the expander according to the first embodiment. FIG. 3 is a schematic explanatory view showing the expander of Embodiment 1 in a cross section, and is an explanatory view showing a closed state of the high-pressure outlet. FIG. 4 is a schematic explanatory view showing the expander during the first operation of the first embodiment in a cross-sectional view, and illustrates the operation of the eccentric part at every rotation angle of 90 °. FIG. 5 is a schematic explanatory view showing the expander of Embodiment 1 in a cross section, and is an explanatory view showing an open state of the high-pressure outlet. FIG. 6 is a schematic explanatory view showing the expander during the second operation of the first embodiment in a cross-sectional view, and illustrates the operation of the eccentric part at every rotation angle of 90 °. FIG. 7 is a schematic explanatory view showing the expander of Embodiment 2 in a cross section, and is an explanatory view showing a closed state of the high-pressure outlet. FIG. 8 is a schematic explanatory view showing the expander of Embodiment 2 in a cross section, and is an explanatory view showing an open state of the high-pressure outlet.

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

<Embodiment 1>
As shown in FIGS. 1-6, the refrigerating apparatus of this embodiment comprises an air conditioner (10), and this air conditioner (10) is a heat pump type air that is switched between indoor cooling and heating. It is configured in a harmony device.

-Overall configuration of air conditioner-
The air conditioner (10) includes a refrigerant circuit (11), and the refrigerant circuit (11) is configured as a closed circuit in which a refrigerant circulates to perform a refrigeration cycle. The refrigerant circuit (11) is filled with carbon dioxide (CO ₂ ) as a refrigerant. That is, the refrigerant circuit (11) is configured to compress carbon dioxide to a critical pressure or higher and perform a so-called supercritical refrigeration cycle. The refrigerant circuit (11) includes a compression / expansion unit (30), an outdoor heat exchanger (12), an indoor heat exchanger (13), a four-way switching valve (14), a rectifier circuit (15), and a pre-expansion valve (17). And.

    The compression / expansion unit (30) includes a casing (31) formed in a vertically long cylindrical sealed container shape. The casing (31) houses a compressor (32), an electric motor (33), and an expander (40) in order from the lower part to the upper part. The compressor (32), the electric motor (33), and the expander (40) are connected by a single output shaft (34).

    The compressor (32) is a rotary positive displacement compressor, and is configured as a so-called oscillating piston type. The refrigerant compressed by the compressor (32) is discharged into the casing (31) through the discharge port. That is, the compression / expansion unit (30) has a so-called high-pressure dome type in which the casing (31) is filled with the high-pressure refrigerant.

    The electric motor (33) includes a stator (35) fixed to the inner peripheral surface of the casing (31), and a rotor (36) positioned inside the stator (35) and connected to the output shaft (34). ing. The electric motor (33) is an inverter type variable speed motor whose output frequency is adjusted by an inverter.

    The expander (40) is a so-called two-cylinder expander, and includes a first expansion mechanism (41) and a second expansion mechanism (42). The first expansion mechanism (41) and the second expansion mechanism (42) are rotary positive displacement expanders, and are configured as so-called oscillating piston types. The first expansion mechanism (41) and the second expansion mechanism (42) are connected in series, the first expansion mechanism (41) is the upstream expansion mechanism, and the second expansion mechanism (42) is the downstream expansion. The mechanism is configured. The displacement volume of the first expansion mechanism (41) is smaller than the displacement volume of the second expansion mechanism (42). The first expansion mechanism (41) and the second expansion mechanism (42) are coupled to the output shaft (34).

    The compression / expansion unit (30) is connected to the suction pipe (21), the discharge pipe (22), the inflow pipe (23), and the outflow pipe (24). The suction pipe (21) passes through the casing (31) and is directly connected to the suction side of the compressor (32). The discharge pipe (22) passes through the casing (31) and opens into the casing (31). The inflow pipe (23) penetrates the casing (31) and is directly connected to the suction side (inflow side) of the first expansion mechanism (41). The outflow pipe (24) penetrates the casing (31) and is directly connected to the discharge side (outflow side) of the second expansion mechanism (42).

    The outdoor heat exchanger (12) and the indoor heat exchanger (13) are configured as a cross fin type fin-and-tube heat exchanger.

    The four-way switching valve (14) has four ports. The first port communicates with the suction pipe (21), the second port communicates with the discharge pipe (22), the third port communicates with one end of the outdoor heat exchanger (12), and the fourth port , Communicated with one end of the indoor heat exchanger (13). The four-way switching valve (14) includes a state in which the first port and the fourth port communicate with each other, and a state in which the second port and the third port communicate with each other (state indicated by a solid line in FIG. 1), The second port and the third port communicate with each other and the second port and the fourth port communicate with each other (state indicated by a broken line in FIG. 1).

    The rectifier circuit (15) is configured by connecting four pipes having a check valve (16) in a bridge shape. The rectifier circuit (15) is connected to the outdoor heat exchanger (12), the indoor heat exchanger (13), and the inflow pipe (23) on the suction side and the outflow pipe (24) on the discharge side of the expander (40). Even if the refrigerant circulation direction is changed in accordance with the switching of the four-way switching valve (14), the refrigerant is always circulated in the same direction to the expander (40). The rectifier circuit (15) may be replaced with a four-way switching valve. The pre-expansion valve (17) is provided between the rectifier circuit (15) and the suction side of the expander (40). The pre-expansion valve (17) constitutes a flow rate adjustment valve whose opening degree can be adjusted.

    A bypass pipe (25) is connected to the refrigerant circuit (11). The bypass pipe (25) has one end connected to the pipe between the pre-expansion valve (17) and the expander (40) of the inflow pipe (23), and the other end connected to the outflow pipe (24). . The bypass pipe (25) is provided with a bypass valve (18). The bypass valve (18) constitutes a flow rate adjusting valve whose opening degree is adjustable.

-Configuration of expander-
As shown in FIGS. 2, 3, and 5, the expander (40) includes a second expansion mechanism (42) disposed above the first expansion mechanism (41).

    The first expansion mechanism (41) includes a first cylinder (50) and a first piston (51), and the second expansion mechanism (42) includes a second cylinder (60) and a second piston (61). ). Each expansion mechanism (41, 42) is configured such that the piston (51, 61) as the second member rotates eccentrically relative to the cylinder (50, 60) as the first member.

    The cylinders (50, 60) are formed in a substantially cylindrical shape with both upper and lower ends open. The inner diameter and thickness of the first cylinder (50) are shorter than the inner diameter and thickness of the second cylinder (60). The lower end surface of the first cylinder (50) is closed by the front head (43), and the upper end surface is closed by the intermediate plate (44). The lower end surface of the second cylinder (60) is closed by the intermediate plate (44), and the upper end surface is closed by the rear head (45). That is, the front head (43), the intermediate plate (44), and the rear head (45) constitute a closing member that closes the end of the cylinder (50, 60). Further, these closing members (43, 44, 45) and the cylinders (50, 60) constitute a fixing member fixed to the casing (31). The first expansion mechanism (41) includes a front head (43), a first cylinder (50), and an intermediate plate (44), and the second expansion mechanism (42) includes an intermediate plate ( 44), a second cylinder (60), and a rear head (45).

    An annular first piston (51) is accommodated in the first cylinder (50), and a first expansion chamber (52) is defined between the first cylinder (50) and the first piston (51). Is formed. An annular second piston (61) is accommodated in the second cylinder (60), and a second expansion chamber (62) is defined between the second cylinder (60) and the second piston (61). Is formed. The inner diameter, outer diameter, and thickness of the first piston (51) are shorter than the inner diameter, outer diameter, and thickness of the second piston (51). Inside the first piston (51) is a first eccentric part (34a) of the output shaft (34), and inside the second piston (61) is a second eccentric part (34b) of the output shaft (34). Are fitted.

    As shown in FIG. 3, the first expansion mechanism (41) has a first blade (53) and a pair of first bushes (54), and the second expansion mechanism (42) has a second blade (63). And a pair of second bushes (64). The blades (53, 63) are formed in a plate shape extending radially outward from the outer peripheral surface of the piston (51, 61). The pair of bushes (54, 64) is provided in a bush groove formed in the cylinder (50, 60).

    The outflow end of the main suction passage (46) is open in the first expansion chamber (52) of the first cylinder (50). The main suction passage (46) is formed by extending the first cylinder (50) in the radial direction, and the inflow pipe (23) is connected to the inflow end side thereof (see FIG. 2). The first expansion chamber (52) has an inflow end of the communication passage (47). The communication path (47) is formed in the intermediate plate (44) in the axial direction. The outflow end of the main suction passage (46) and the inflow end of the communication passage (47) in the first expansion mechanism (41) are blocked by the first blade (53) and are close to each other.

    The outflow end of the communication passage (47) is opened in the second expansion chamber (62) of the second cylinder (60). The second expansion chamber (62) has an inflow end of the outflow passage (48). The outflow passage (48) is formed by extending the second cylinder (60) in the radial direction, and the outflow pipe (24) is connected to the outflow end side thereof (see FIG. 2). The outflow end of the communication path (47) of the second expansion mechanism (42) and the inflow end of the outflow path (48) are blocked by the second blade (63) and are close to each other.

    The first expansion chamber (52) is partitioned into two spaces by a first blade (53). In FIG. 3, the space partitioned on the left side of the first blade (53) constitutes a high-pressure space (52a) communicating with the main suction passage (46), and the space partitioned on the right side communicates with the communication passage (47). The first expansion space (52b) is configured.

    The second expansion chamber (62) is partitioned into two spaces by a second blade (63). In FIG. 3, the space partitioned on the left side of the second blade (63) constitutes the second expansion space (62a) communicating with the communication passage (47), and the space partitioned on the right side is the outflow passage (48). A low-pressure space (62b) that communicates is configured.

    Further, as shown in FIGS. 2, 3 and 5, the auxiliary suction passage (70) is connected to the front head (43) and the first cylinder (50) of the first expansion mechanism (41). The back pressure passage (71) is connected to the front head (43).

    The auxiliary suction passage (70) includes an auxiliary passage (72) formed in the front head (43) and the first cylinder (50) and an auxiliary pipe (72) connecting the auxiliary passage (72) to the refrigerant circuit (11). 73). The auxiliary passage (72) includes a switching valve (80) and an outlet passage (74). The outlet passage (74) is formed on the lower surface of the first cylinder (50), for example, and is closed by the front head (43). The inflow end of the outlet passage (74) is connected to the switching valve (80), while the outflow end of the outlet passage (74) is connected to the first expansion chamber (52) of the main suction passage (46). The first piston (51) opens from the opening position at a position advanced in the rotation direction. One end of the auxiliary pipe (73) is connected to the inflow side of the switching valve (80), and the other end of the auxiliary pipe (73) is connected to the pre-expansion valve (17) and the bypass pipe (25) of the inflow pipe (23). ) Is connected between the connecting part. Accordingly, the auxiliary suction passage (70) is configured to supply the high-pressure refrigerant of the refrigerant circuit (11) to the first expansion chamber (52) separately from the main suction passage (46).

    The back pressure passage (71) is formed in the front head (43) and extends in the radial direction in a semicircular arc shape along the outer peripheral surface of the first expansion chamber (52). Further, the inflow end of the back pressure passage (71) is connected to the main suction passage (46), while the outflow end of the back pressure passage (71) is connected to the switching valve (80) of the sub passage (72). It is connected. The back pressure passage (71) is formed, for example, on the upper surface of the front head (43) and is closed by the first cylinder (50).

    The switching valve (80) is mainly provided in the bulging portion (55) of the front head (43), and the valve chamber (81) includes a valve body (82) and a compression spring (83) as an urging member. It has. In addition, in the cross section of FIG. 3 etc., the said switching valve (80) is displayed on the same surface as the exit channel | path (74) and back pressure channel | path (71) of a subchannel | path (72).

    The valve chamber (81) has a high pressure inlet (84), a high pressure outlet (85), and a back pressure port (86). The high pressure inlet (84) of the valve chamber (81) is connected to an auxiliary pipe (73), and the high pressure outlet (85) of the valve chamber (81) is connected to an outlet passage (74), while the valve The outflow end of the back pressure passage (71) is connected to the back pressure port (86) of the chamber (81).

    The valve body (82) moves directly inside the valve chamber (81), and the primary side chamber (87) into which the refrigerant in the auxiliary pipe (73) is introduced, and the high pressure of the refrigerant circuit (11) as back pressure. The valve chamber (81) is partitioned into a secondary chamber (88) into which the refrigerant is introduced via the back pressure passage (71), and the high pressure outlet (85) is opened and closed.

    The compression spring (83) is provided in the primary chamber (87) and urges the valve body (82) in the valve opening direction. In other words, the valve body (82) includes the primary side pressure of the primary chamber (87) obtained by adding the refrigerant pressure of the auxiliary suction passage (70) and the spring force of the compression spring (83), and the main suction passage (46). The secondary side pressure of the secondary side chamber (88), which is the high-pressure refrigerant pressure of And the said switching valve (80) is comprised so that the said high pressure outlet (85) may be opened and closed by the differential pressure | voltage of a primary side pressure and a secondary side pressure.

    The auxiliary pipe (73) is provided with a control valve (75). The control valve (75) is configured to open and close the auxiliary suction passage (70). That is, when the control valve (75) is closed, as shown in FIG. 3, the introduction of the high-pressure refrigerant in the auxiliary suction passage (70) to the switching valve (80) stops, and the primary side chamber (87) The primary side pressure decreases, and the valve body (82) is closed by the secondary side pressure. On the other hand, when the control valve (75) is opened, as shown in FIG. 5, the high-pressure refrigerant in the auxiliary suction passage (70) is introduced into the primary chamber (87) of the switching valve (80), and the valve body ( 82) is acted on by adding the high-pressure refrigerant pressure in the auxiliary suction passage (70) and the spring force of the compression spring (83), and the valve element (82) opens against the secondary pressure. To do.

    The control valve (75) is constituted by a flow rate adjustment valve (electric valve) capable of adjusting the opening, but may be an on-off valve.

-Operation of the air conditioner-
First, the operation of the air conditioner (10) will be described. The air conditioner (10) is switched between a cooling operation and a heating operation.

-Cooling operation-
During cooling operation, the four-way switching valve (14) is set to the state shown by the solid line in FIG. 1, and the refrigeration cycle is performed in which the outdoor heat exchanger (12) serves as a radiator and the indoor heat exchanger (13) serves as an evaporator. Is called.

    The refrigerant compressed by the compressor (32) is discharged into the casing (31) of the compression / expansion unit (30). The high-pressure refrigerant in the casing (31) flows from the discharge pipe (22) to the outdoor heat exchanger (12). In the outdoor heat exchanger (12), the refrigerant radiates heat to the outdoor air.

    The high-pressure refrigerant radiated by the outdoor heat exchanger (12) flows into the expander (40) through the inflow pipe (23). In the expander (40), the high-pressure refrigerant expands and power is recovered from the high-pressure refrigerant. The low-pressure refrigerant after expansion flows through the indoor heat exchanger (13) via the outflow pipe (24). In the indoor heat exchanger (13), the refrigerant absorbs heat from the room air, and the room air is cooled. The refrigerant evaporated in the indoor heat exchanger (13) is sucked into the compressor (32) through the suction pipe (21) and compressed again.

-Heating operation-
During the heating operation, the four-way selector valve (14) is set to the state shown by the broken line in FIG. 1, and a refrigeration cycle is performed in which the indoor heat exchanger (13) serves as a radiator and the outdoor heat exchanger (12) serves as an evaporator. Is called.

    The refrigerant compressed by the compressor (32) is discharged into the casing (31) of the compression / expansion unit (30). The high-pressure refrigerant in the casing (31) flows from the discharge pipe (22) through the indoor heat exchanger (13). In the indoor heat exchanger (13), the refrigerant dissipates heat to the room air, and the room air is heated.

    The high-pressure refrigerant radiated by the indoor heat exchanger (13) flows into the expander (40) through the inflow pipe (23). In the expander (40), the high-pressure refrigerant expands and power is recovered from the high-pressure refrigerant. The low-pressure refrigerant after expansion flows through the outdoor heat exchanger (12) through the outflow pipe (24). In the outdoor heat exchanger (12), the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (12) is sucked into the compressor (32) through the suction pipe (21) and compressed again.

-Operation of expander (40)-
Next, the operation of the expander (40) will be described. The expander (40) switches between the first operation and the second operation according to the open / close state of the control valve (75). The first operation and the second operation are appropriately switched according to a change in the outside air temperature.

-First operation-
In the first operation, the control valve (75) is closed. As a result, since the sub suction passage (70) is closed, the high-pressure refrigerant in the sub suction passage (70) is not supplied to the primary chamber (87) of the switching valve (80). Therefore, the acting force of the valve body (82) of the switching valve (80) is higher than the primary pressure at which the spring force of the compression spring (83) acts, and is the secondary side that is the high-pressure refrigerant pressure in the back pressure passage (71). Pressure increases. Therefore, as shown in FIG. 3, the valve body (82) closes the high-pressure outlet (85), and the high-pressure refrigerant is supplied to the expander (40) only from the main suction passage (46). In this first operation, the space from the outflow end (opening of the first expansion chamber) of the auxiliary suction passage (70) to the control valve (75) is maintained in a pressure atmosphere of the expansion space, that is, a so-called intermediate pressure state. The

    In this state, in the expander (40), as shown in FIG. 4, the process of sucking the refrigerant (suction process), the process of expanding the refrigerant (expansion process), and the process of discharging the refrigerant (discharge) Process) is repeated in order.

    In the suction process, high-pressure refrigerant is sucked into the first expansion chamber (52) of the first expansion mechanism (41). Specifically, in the first expansion mechanism (41), when the rotation angle of the eccentric part (34a, 34b) is slightly rotated from the state of 0 ° (see FIG. 4A), the first piston (51) and the first piston The position of contact with one cylinder (50) passes through the outflow opening of the main suction passage (46), and high-pressure refrigerant begins to flow from the main suction passage (46) into the high-pressure space (52a). Thereafter, the rotation angles of the eccentric portions (34a, 34b) gradually increase to 90 ° (see FIG. 4B), 180 ° (see FIG. 4C), and 270 ° (see FIG. 4D). Along with this, the high-pressure refrigerant flows into the high-pressure space (52a). The inflow of high-pressure refrigerant from the main suction passage (46) into the high-pressure space (52a) is performed until the rotation angle of the eccentric portions (34a, 34b) reaches about 360 ° (the outflow opening of the main suction passage (46) is closed). Continue).

    The auxiliary suction passage (70) is closed by the valve body (82) of the switching valve (80). Therefore, the refrigerant is not introduced from the auxiliary suction passage (70) into the high-pressure space (52a).

    In the next expansion process, the refrigerant expands in the first expansion chamber (52) and the second expansion chamber (62). Specifically, in the first expansion mechanism (41), when the rotation angle of the eccentric part (34a, 34b) is slightly rotated from a state of 360 °, the high-pressure space (52a) partitioned from the main suction passage (46) is formed. The high-pressure space (52a) communicates with the communication path (47) and becomes the first expansion space (52b). Furthermore, the first expansion space (52b) communicates with the second expansion space (62a) of the second expansion mechanism (42) via the communication path (47). As the rotation angle of the eccentric portions (34a, 34b) gradually increases to 540 ° and 630 °, the volume of the first expansion space (52b) is reduced, but the volume of the second expansion space (62a) is more than that. Enlarged. The expansion of the sum of the volumes of the first expansion space (52b) and the second expansion space (62a) continues until just before the rotation angle of the eccentric portions (34a, 34b) reaches 720 °. As a result, during the expansion process, the refrigerant expands and is depressurized, and the power of the expanded refrigerant is converted into rotational power of the output shaft (34) via the piston (51, 61) and the eccentric part (34a, 34b). Is done. Thereby, the drive power of the compressor (32) by an electric motor (33) is reduced, and energy saving of an air conditioning apparatus (10) is achieved.

    In the next discharge process, the refrigerant flows out from the second expansion chamber (62) of the second expansion mechanism (42). Specifically, when the rotation angle of the eccentric part (34a, 34b) is slightly rotated from the state of 720 °, the second expansion space (62a) and the outflow passage (48) communicate with each other, and the second expansion space (62a ) Becomes the low pressure chamber (62b). As the rotation angles of the eccentric portions (34a, 34b) gradually increase to 810 °, 900 °, and 990 °, the refrigerant in the low pressure chamber (62b) flows out to the outflow passage (48). The refrigerant outflow from the low pressure chamber (62b) to the outflow passage (48) continues until the rotation angle of the eccentric parts (34a, 34b) reaches about 1080 °.

-Second operation-
In the second operation, the control valve (75) is opened. As a result, since the auxiliary suction passage (70) is opened, the high-pressure refrigerant in the auxiliary suction passage (70) is supplied to the primary side chamber (87) of the switching valve (80). Therefore, the acting force of the valve body (82) of the switching valve (80) is the primary pressure obtained by adding the high-pressure refrigerant pressure and the spring force of the compression spring (83) to the high-pressure refrigerant pressure in the back pressure passage (71). It becomes larger than the secondary side pressure which is. Therefore, as shown in FIG. 5, the valve body (82) opens the high-pressure outlet (85), and the high-pressure refrigerant is supplied from the main suction passage (46) to the expander (40) and is also sub-suctioned. It is also supplied to the expander (40) from the passage (70).

    In such a state, as shown in FIG. 6, in the expander (40), the suction process, the expansion process, and the discharge process are sequentially repeated in the same manner as in the first operation.

    In the inhalation process, as described above, the rotation angles of the eccentric portions (34a, 34b) are 0 ° (see FIG. 6A), 90 ° (see FIG. 6B), 180 ° (see FIG. 6C). )) As the pressure gradually increases to 270 ° (see FIG. 6D), the high-pressure refrigerant flows from the main suction passage (46) into the high-pressure space (52a). Here, when the rotation angle of the eccentric part (34a, 34b) reaches a predetermined angle, for example, 220 °, the auxiliary suction passage (70) communicates with the high-pressure space (52a). Therefore, in the suction process of the second operation, the high-pressure refrigerant is introduced from both the main suction passage (46) and the sub suction passage (70).

    Furthermore, after the rotation angle of the eccentric part (34a, 34b) reaches 360 °, the first expansion space (52b) communicates with the second expansion space (62a) via the communication path (47). When the rotation angle of the eccentric portions (34a, 34b) is slightly rotated from the state of 360 °, the first expansion chamber (52) is partitioned from the main suction passage (46), but the sub suction passage (70) is The inhalation process continues while communicating with the one expansion chamber (52).

    In the next expansion process, the rotation angle of the eccentric part (34a, 34b) advances to, for example, 580 °, and the first expansion chamber (52) is partitioned from the auxiliary suction passage (70). Thereafter, the refrigerant expands in the first expansion space (52b) and the second expansion space (62b) as described above.

    In the next discharge process, after the rotation angle of the eccentric part (34a, 34b) reaches 720 °, the second expansion space (62a) and the outflow path (48) communicate with each other. As the rotation angle of the eccentric portions (34a, 34b) gradually increases to 810 °, 900 °, 990 °, 1080 °, the refrigerant in the low pressure chamber (62b) flows out to the outflow path (48). Here, the pressure of the refrigerant flowing out from the low pressure chamber (62b) during the second operation becomes higher than that during the first operation due to the introduction of the refrigerant from the auxiliary suction passage (70).

    As described above, in the expander (40) of the present embodiment, the pressure of the refrigerant flowing out from the expander (40) can be appropriately adjusted by selectively switching between the first operation and the second operation. it can. As a result, for example, even when the suction pressure of the compressor (32) changes due to switching between cooling operation and heating operation or a change in the outside air temperature, the expander (40) follows this. Thus, the refrigerant can be expanded, and so-called overexpansion can be prevented.

-Effect of the embodiment-
According to the above embodiment, the auxiliary suction passage (70) can be opened and closed by the switching valve (80) and the expansion ratio can be adjusted, so that the refrigerant circulation amount between the compressor (32) and the expander (40) can be reduced. Can be balanced. As a result, for example, even if the operating conditions of the refrigeration apparatus change, it is possible to avoid the occurrence of overexpansion on the outflow side of the expander (40) and to suppress the generation of reverse torque. It is possible to improve the power recovery efficiency in 40) and to improve the mechanical reliability.

    Further, since the suction volume can be made variable by switching the switching valve (80), the expander operating area can be expanded.

    Further, since only one back pressure passage (71) of the switching valve (80) is formed, it is not necessary to form two back pressure passages as in the prior art, and the switching valve (80) Since only one control valve (75) for switching 80) is provided in the auxiliary suction passage (70), the number of parts can be reduced and the configuration can be simplified.

    Further, since the switching valve (80) is provided in the vicinity of the expansion chamber (52), the dead volume can be reduced. That is, when only the control valve (75) is provided in the auxiliary suction passage (70), the control valve (75) is provided in the auxiliary pipe (73) connected to the refrigerant circuit (11). Between 75) and the expansion chamber (52) is the dead volume of the closed space that does not contribute to refrigerant expansion. In this embodiment, since the switching valve (80) is provided in addition to the control valve (75), the switching valve (80) can be disposed in the vicinity of the first expansion chamber (52). Can be almost eliminated. Thereby, for example, when a dead volume is formed, the power recovery amount (work amount) is reduced due to the dead volume, whereas in this embodiment, the power recovery amount is reduced. The desired power recovery efficiency can be obtained with the expander (40).

    Further, since the back pressure passage (71) is formed in the expander body (43), the sub suction passage (70) can be guided from the refrigerant circuit (11), and the cross sectional area of the sub suction passage (70) can be obtained. Can be secured sufficiently. As a result, the resistance of the auxiliary suction passage (70) can be reduced, so that the efficiency can be improved. Further, since the resistance of the auxiliary suction passage (70) can be reduced, the control range of the refrigerant flow rate can be increased, and the operation area can be further expanded.

    That is, conventionally, since the auxiliary suction passage is formed in the expander body, the formation of the auxiliary suction passage is restricted, and a sufficient cross-sectional area cannot be secured, and the pressure loss of the auxiliary suction passage is large. As a result, there is a problem that the performance is reduced and the operation area is reduced due to the reduction of the flow control width.

    On the other hand, according to the present embodiment, the auxiliary suction passage (70) can be guided from the refrigerant circuit (11), and the resistance of the auxiliary suction passage (70) can be reduced. In addition, the operation area can be expanded by expanding the flow rate control width.

    Further, since the auxiliary suction passage (70) is switched by the switching valve (80), unlike the check valve, chattering at the time of suction can be prevented and the open state can be reliably maintained. Loss can be reduced and noise caused by vibration can be reduced.

<Embodiment 2 of the invention>
Next, a second embodiment of the present invention will be described in detail based on the drawings.

    In the present embodiment, as shown in FIGS. 7 and 8, the high-pressure refrigerant flowing into the expander (40) through the back pressure passage (71) of the first embodiment is transferred to the secondary side chamber (88) of the switching valve (80). Instead of being guided, the back pressure passage (71) guides the low-pressure refrigerant flowing out of the expander (40) to the secondary side chamber (88) of the switching valve (80).

    Specifically, one end of the back pressure passage (71) is connected to the outflow passage (48) of the second expansion mechanism (42), and the other end is connected to the back pressure port (86) of the switching valve (80). Has been. The back pressure passage (71) is, for example, from the second cylinder (60) of the second expansion mechanism (42) through the intermediate plate (44) and the first cylinder (50) of the first expansion mechanism (41). And formed over the front head (43) of the first expansion mechanism (41).

    On the other hand, in the switching valve (80), the compression spring (83) is provided in the secondary side chamber (88), and urges the valve body (82) in the valve closing direction. That is, the valve body (82) of the switching valve (80) has a secondary pressure in the secondary chamber (88), which is a refrigerant pressure in the sub suction passage (70), and a low pressure refrigerant pressure in the outflow passage (48). The secondary side pressure of the secondary side chamber (88), which is the sum of the spring force of the compression spring (83), acts. And the said switching valve (80) is comprised so that the said high pressure outlet (85) may be opened and closed by the differential pressure | voltage of a primary side pressure and a secondary side pressure.

    Accordingly, as shown in FIG. 7, the first operation of the expander (40) is that the control valve (75) is closed and the auxiliary suction passage (70) is closed. High-pressure refrigerant is not supplied to the primary chamber (87) of the switching valve (80). As a result, the acting force of the valve body (82) of the switching valve (80) is the primary pressure obtained by adding the low pressure refrigerant pressure of the back pressure passage (71) and the spring force of the compression spring (83). It becomes larger than the side pressure. Therefore, the valve body (82) closes the high-pressure outlet (85), and the high-pressure refrigerant is supplied to the expander (40) only from the main suction passage (46). In this first operation, the space from the outflow end (opening of the first expansion chamber) of the auxiliary suction passage (70) to the control valve (75) is maintained in a pressure atmosphere of the expansion space, that is, a so-called intermediate pressure state. The

    In the first operation, as in the first embodiment, the high-pressure refrigerant is supplied to the expander (40) only from the main suction passage (46), and the first piston (51) of the first expansion mechanism (41) This is performed by rotating the second piston (61) of the second expansion mechanism (42).

    Further, the second operation of the expander (40) is, as shown in FIG. 8, because the control valve (75) is opened and the auxiliary suction passage (70) is opened. High-pressure refrigerant is supplied to the primary side chamber (87) of the switching valve (80). Therefore, the acting force of the valve body (82) of the switching valve (80) is that the primary pressure, which is the high pressure refrigerant pressure, is the low pressure refrigerant pressure in the back pressure passage (71) and the spring force of the compression spring (83). Becomes larger than the secondary pressure. Therefore, the valve body (82) opens the high-pressure outlet (85), and the high-pressure refrigerant is supplied from the main suction passage (46) to the expander (40) and is also expanded from the sub suction passage (70). Supplied to the machine (40).

    In the second operation, as in the first embodiment, the high-pressure refrigerant is supplied from the main suction passage (46) and the sub suction passage (70) to the expander (40), and the first expansion mechanism (41) The first piston (51) and the second piston (61) of the second expansion mechanism (42) are rotated. Other configurations, operations, and effects are the same as those in the first embodiment.

<Other embodiments>
The present invention may be configured as follows for each of the above embodiments.

    In each of the above-described embodiments, a so-called rotary positive displacement expander (40) is applied. However, for example, other expanders such as a scroll expander may be applied to the present invention.

    Moreover, although each said embodiment demonstrated the integral type compression-expansion unit (30) with which the compressor (32) and the expander (40) were connected within the same casing (31), this invention is a compressor. (32) and the expander (40) may be formed in separate casings. That is, the present invention may be, for example, an expander of a system in which the recovery power of the expander is regenerated by a generator connected to the expander.

    That is, when the compressor and the expander are configured separately, the rotation speed control of the compressor and the expander is performed separately, so that the operating area of the expander itself is integrated into the integrated compression / expansion unit (30). It becomes wider than that. When the present invention is applied to this separate type expander, the operation area is further expanded.

    Moreover, although the said embodiment applies the air conditioning apparatus which air-conditions a room | chamber interior, this invention applies refrigeration apparatuses, such as a water heater, a chiller unit, a refrigerator which performs refrigeration or freezing in a warehouse, for example. May be.

    In the above embodiment, one auxiliary suction passage (70) and one switching valve (80) are provided to form two so-called closed cut points. However, the present invention provides the auxiliary suction passage (70) and the switching valve. Two or more valves (80) may be provided, and three or more so-called closed cut points may be configured.

    In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

    As described above, the present invention is useful for an expander that recovers the power of the refrigerant expanded in the expansion chamber and a refrigeration apparatus including the expander.

10 Air conditioning equipment (refrigeration equipment)
11 Refrigerant circuit 30 Compression / expansion unit 32 Compressor 40 Expander 41 First expansion mechanism 42 Second expansion mechanism 46 Main suction passage 50, 60 Cylinder 51, 61 Piston 52, 62 Expansion chamber 53, 63 Blade 70 Sub suction passage 71 Back Pressure passage 72 Sub passage 73 Auxiliary piping 75 Control valve 80 Switching valve 81 Valve chamber 82 Valve element 83 Compression spring (biasing member)
87 Primary side chamber 88 Secondary side chamber

Claims (7)

An expander that recovers the power of the refrigerant by expanding the high-pressure refrigerant in the refrigerant circuit (11) in the expansion chamber (52) from the rotation of the rotating member (51),
A main suction passage (46) for supplying high-pressure refrigerant to the expansion chamber (52);
An auxiliary suction passage (70) that opens to a position advanced in the rotational direction of the rotating member (51) from the opening position of the expansion chamber (52) of the main suction passage (46) and supplies high-pressure refrigerant to the expansion chamber (52). )When,
A secondary which is provided in the auxiliary suction passage (70) and is introduced with a primary pressure in a primary chamber (87) communicating with the auxiliary suction passage (70) and a predetermined pressure in the refrigerant circuit (11). A switching valve (80) that opens and closes the auxiliary suction passage (70) based on a pressure difference from the secondary side pressure of the side chamber (88), and supplies and shuts off the high-pressure refrigerant to the expansion chamber (52);
The auxiliary suction passage (70) is located upstream of the switching valve (80), and the switching valve (80) opens and closes the auxiliary suction passage (70). 70) An expander comprising a control valve (75) for opening and closing. In claim 1,
The expansion valve, wherein the switching valve (80) is connected to a back pressure passage (71) for guiding the high-pressure refrigerant of the refrigerant circuit (11) to the secondary chamber (88). In claim 1,
The expansion valve, wherein the switching valve (80) is connected to a back pressure passage (71) for guiding the low-pressure refrigerant of the refrigerant circuit (11) to the secondary chamber (88). In claim 2,
The switching valve (80) divides the valve chamber (81) into a primary side chamber (87) and a secondary side chamber (88), and moves directly inside the valve chamber (81) so that the expansion chamber (81) 52) including a valve body (82) for opening and closing the high-pressure outlet (85) communicating with the valve body (82), and a biasing member (83) for biasing the valve body (82) in the valve opening direction. ) By the differential pressure between the primary side pressure obtained by adding the urging force of the urging member (83) to the refrigerant pressure of) and the secondary side pressure consisting of the high pressure refrigerant pressure in the secondary side chamber (88). An expander characterized by being configured to open and close the high-pressure outlet (85). In claim 3,
The switching valve (80) divides the valve chamber (81) into a primary side chamber (87) and a secondary side chamber (88), and moves directly inside the valve chamber (81) so that the expansion chamber (81) 52) including a valve body (82) for opening and closing the high pressure outlet (85) communicating with the valve body (82), and a biasing member (83) for biasing the valve body (82) in the valve closing direction. ) And the secondary side pressure obtained by adding the urging force of the urging member (83) to the low-pressure refrigerant pressure of the secondary side chamber (88). An expander characterized by being configured to open and close the high-pressure outlet (85). In any one of Claims 1-5,
The back pressure passage (71) is formed in an expander body (43), and the expander is characterized in that A refrigerating apparatus comprising the expander (40) according to any one of claims 1 to 6.

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