JP2015031210A - Rankine cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent working fluid in a shaft seal chamber from being leaked to atmosphere.SOLUTION: A Rankine cycle device 10 has an on-off valve 52 for opening/closing an exhaust passage 51b, and a pressure sensor 53 for detecting pressure between an outlet of an expander 12 and an inlet of a pump 11. Furthermore, the Rankine cycle device 10 has a control part 55 for controlling the on-off valve 52 to close the on-off valve 52 when the pressure sensor 53 detects information that pressure between the outlet expander 12 and the inlet of the pump 11 reaches predetermined pressure.

Description

  The present invention relates to a Rankine cycle apparatus.

  The Rankine cycle device includes a pump that pumps the working fluid, a heat exchanger that exchanges heat with the exhaust heat from the vehicle engine, and a working fluid that is heat-exchanged by the heat exchanger. An expander that outputs mechanical energy and a condenser that condenses the working fluid expanded by the expander. A pump, a heat exchanger, an expander, and a condenser are sequentially connected to form a working fluid path through which the working fluid circulates.

  A pump chamber is formed in the pump housing. A pump shaft extending into the pump chamber is accommodated in the housing. In the pump chamber is housed a pump operating section that operates in accordance with the rotational drive of the pump shaft. Then, the working fluid circulates in the working fluid path by the operation of the pump operating unit accompanying the rotational driving of the pump shaft. A shaft seal member that seals between the housing and the pump shaft is housed in the housing. A shaft seal chamber is defined by the shaft seal member, the pump shaft, the housing, and the pump operating portion. The shaft seal member is an atmospheric shaft seal that prevents the working fluid in the shaft seal chamber from leaking to the atmosphere side by sealing between the housing and the pump shaft. Lubrication between the shaft seal member and the pump shaft is performed by lubricating oil contained in the working fluid supplied into the shaft seal chamber.

  By the way, if the pressure in the shaft seal chamber increases and the pressure in the shaft seal chamber exceeds the pressure resistance of the shaft seal member, the shaft seal member can no longer seal between the housing and the pump shaft. The working fluid in the shaft seal chamber leaks to the atmosphere due to the pressure difference between the pressure and the atmospheric pressure. Therefore, for example, as in Patent Document 1, the difference between the pressure in the shaft seal chamber and the atmospheric pressure is established by communicating the outlet of the expander and the shaft seal chamber through a passage to reduce the pressure in the shaft seal chamber. It is conceivable to reduce the pressure. According to this, the working fluid in the shaft seal chamber is prevented from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber and the atmospheric pressure.

JP 2008-75637 A

  However, when the load applied to the vehicle engine increases due to load fluctuations that occur during travel of the vehicle, the temperature of exhaust heat from the vehicle engine rises. Then, the temperature of the working fluid that exchanges heat with exhaust heat from the vehicle engine in the heat exchanger also rises. The higher the temperature of the working fluid, the higher the condensation pressure required to condense and liquefy the working fluid in the condenser. As a result, the pressure from the expander outlet to the pump inlet in the working fluid path is increased, and therefore the communication from the expander outlet to the pump inlet in the working fluid path is established via a passage that bypasses the condenser. The pressure in the shaft seal chamber is also increased. If the pressure in the shaft seal chamber exceeds the pressure resistance of the shaft seal member, the shaft seal member cannot seal between the housing and the pump shaft, and the pressure difference between the pressure in the shaft seal chamber and atmospheric pressure. As a result, the working fluid in the shaft seal chamber leaks to the atmosphere side.

  By the way, the above-mentioned problem can occur not only in the pump but also in the expander. Specifically, a drive shaft that is rotationally driven by the expander unit is housed in the housing of the expander. Further, a shaft seal member that seals between the housing and the drive shaft is accommodated in the housing. A shaft seal chamber is defined by the shaft seal member, the drive shaft, and the housing.

  For example, the lubricating oil contained in the working fluid is supplied by supplying the working fluid flowing between the outlet of the heat exchanger and the inlet of the expander in the working fluid path to the shaft seal chamber through a passage that bypasses the expander. Thus, lubrication between the shaft seal member and the drive shaft is performed. The passage is provided with a throttle portion, and the working fluid flowing through the passage is decompressed by the throttle portion. The shaft seal chamber is connected from the expander outlet to the pump inlet in the working fluid path, and the working fluid supplied to the shaft seal chamber is supplied from the expander outlet in the working fluid path to the pump. It is refluxed until the entrance.

  Since the shaft seal chamber is connected from the expander outlet to the pump inlet in the working fluid path, the condensation pressure of the condenser increases, and the expander outlet to the pump inlet in the working fluid path As the pressure increases, the pressure in the shaft seal chamber increases. If the pressure in the shaft seal chamber exceeds the pressure resistance of the shaft seal member, the shaft seal member can no longer seal between the housing and the drive shaft, and the pressure difference between the pressure in the shaft seal chamber and atmospheric pressure. As a result, the working fluid in the shaft seal chamber leaks to the atmosphere side.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a Rankine cycle device capable of preventing the working fluid in the shaft seal chamber from leaking to the atmosphere side. is there.

  In the Rankine cycle device that solves the above problems, a pump, a heat exchanger, an expander, and a condenser are sequentially connected to form a working fluid path through which a working fluid circulates. The pump and the expander are fluid machines. A housing chamber is formed in at least one housing of the pump and the expander which are the fluid machines, and a drive shaft extending to the housing chamber is housed in the housing; Includes an operating portion that operates in accordance with the rotational drive of the drive shaft, and a shaft seal member that seals between the housing and the drive shaft is accommodated in the housing. A shaft seal chamber is defined by the seal member, the drive shaft, and the housing. The shaft seal chamber includes a supply passage that supplies the working fluid to the shaft seal chamber, and the shaft casing. A discharge passage that discharges the working fluid in the fluid chamber to the working fluid passage, and the shaft seal member is lubricated by the working fluid discharged from the supply passage to the discharge passage through the shaft seal chamber, The discharge passage is a Rankine cycle device connected between the outlet of the expander and the inlet of the pump, and includes an open / close valve that opens and closes the discharge passage, and from the outlet of the expander to the inlet of the pump A detecting unit for detecting the pressure between and until the on-off valve, and closing the on-off valve when detecting that the pressure detected by the detecting unit has reached a predetermined pressure And a controller for controlling the on-off valve.

  According to this, the shaft seal member can be lubricated by the working fluid discharged from the supply passage to the discharge passage through the shaft seal chamber. Further, since the discharge passage is connected between the outlet of the expander and the inlet of the pump, the pressure in the shaft seal chamber can be brought close to the pressure between the outlet of the expander and the inlet of the pump, It is possible to prevent the working fluid in the shaft seal chamber from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber and the atmospheric pressure.

  Here, since the throttle part is not provided in the discharge passage, the throttle part is provided in the discharge passage, so that the pressure in the shaft seal chamber is increased from the pressure on the supply passage side to the pump inlet from the outlet of the expander. There will be no intermediate pressure between the two. Therefore, it can be prevented that the pressure in the shaft seal chamber becomes an intermediate pressure that is always constant, and a constant pressure is always applied to the shaft seal member.

  And a control part controls an on-off valve so that an on-off valve may be closed when the information to the effect that the pressure detected by the detection part reached the predetermined pressure is detected. Here, the “predetermined pressure” refers to a pressure lower than the pressure resistance of the shaft seal member. For this reason, the shaft seal chamber is not in communication with the space between the outlet of the expander and the pump inlet, and the pressure in the shaft seal chamber can be prevented from becoming higher than a predetermined pressure. As a result, it can be prevented that the pressure in the shaft seal chamber exceeds the pressure resistance of the shaft seal member and the shaft seal member cannot seal between the housing and the drive shaft. It is possible to prevent the working fluid in the shaft seal chamber from leaking to the atmosphere due to the pressure difference between the pressure and the atmospheric pressure.

  In the Rankine cycle apparatus, it is preferable that the supply passage is connected to a portion of the working fluid passage where the pressure is higher than that of the discharge passage, and a throttle portion is provided in at least a part of the supply passage. According to this, the flow of the working fluid discharged from the supply passage to the discharge passage through the shaft seal chamber can be made smooth.

  In the Rankine cycle device, the control unit controls the on-off valve so as to open the on-off valve when detecting that the pressure detected by the detection unit is lower than a predetermined pressure. It is preferable.

  According to this, when the pressure detected by the detection unit is lower than the predetermined pressure, the shaft seal chamber communicates with the shaft seal chamber from the expander outlet to the pump inlet. The pressure in the chamber can be brought close to the pressure between the outlet of the expander and the inlet of the pump. As a result, it is possible to prevent the working fluid in the shaft seal chamber from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber and the atmospheric pressure.

In the Rankine cycle device, it is preferable that the detection unit detects a pressure between an outlet of the expander and an inlet of the pump.
According to this, since the control unit controls the on-off valve using information on the pressure between the outlet of the expander and the inlet of the pump, the pressure in the shaft seal chamber becomes higher than a predetermined pressure. This can be easily prevented.

In the Rankine cycle device, it is preferable that a seal member for sealing between the housing chamber and the shaft seal chamber is provided between the housing and the drive shaft.
According to this, it is possible to prevent the working fluid in the storage chamber from flowing into the shaft seal chamber through the space between the housing and the drive shaft. Therefore, it is possible to prevent the working fluid in the storage chamber from flowing into the shaft seal chamber and increasing the pressure in the shaft seal chamber.

  According to this invention, it is possible to prevent the working fluid in the shaft seal chamber from leaking to the atmosphere side.

The schematic diagram which shows the Rankine-cycle apparatus in 1st Embodiment. The schematic diagram which shows the Rankine-cycle apparatus in 2nd Embodiment. The schematic diagram which shows the Rankine-cycle apparatus in another embodiment.

(First embodiment)
Hereinafter, a first embodiment in which the Rankine cycle apparatus is embodied will be described with reference to FIG.

  As shown in FIG. 1, the Rankine cycle apparatus 10 includes a composite fluid machine 20 in which a pump 11 and an expander 12 that are fluid machines are integrated. The Rankine cycle device 10 is formed with a working fluid path 15 through which a working fluid circulates by sequentially connecting a pump 11, a heat exchanger 13, an expander 12, and a condenser 14.

  The housing 21 of the composite fluid machine 20 is formed of a housing main body 22 having a covered cylindrical shape, and a rear housing 23 joined to the opening end of the housing main body 22. A drive shaft 24 is accommodated in the housing body 22.

  A concave portion 221 a is formed on the surface of the lid portion 22 a of the housing body 22 facing the housing 21 so as to surround the drive shaft 24. Then, the side plate 26 is fixed to the surface of the lid 22a facing the housing 21, whereby the recess 221a is closed, and a pump chamber 27 serving as a storage chamber is defined between the lid 22a and the side plate 26. ing. A driven gear 28 is rotatably accommodated in the pump chamber 27. A drive shaft 24 extends in the pump chamber 27. A main drive gear 29 attached to the drive shaft 24 is accommodated in the pump chamber 27. The driven gear 28 and the main driving gear 29 are accommodated in the pump chamber 27 while being engaged with each other. The driven gear 28 and the main driving gear 29 constitute a pump operating unit 30 as an operating unit that operates in accordance with the rotational drive of the drive shaft 24.

  A suction passage 31 communicating with the pump chamber 27 (recess 221a) is formed in the lid portion 22a. The suction passage 31 is formed in the upper part of the composite fluid machine 20 so as to open on the upper surface of the housing body 22. Further, a discharge passage 32 communicating with the pump chamber 27 (recess 221a) is formed in the lid portion 22a. The discharge passage 32 is formed so as to be positioned below the pump chamber 27.

  A substantially cylindrical support block 34 constituting a part of the housing 21 is fixed in the housing main body 22. The inside of the housing body 22 is partitioned by the support block 34 into the rear housing 23 side and the lid portion 22a side. The other end side (rear housing 23 side) of the drive shaft 24 passes through the side plate 26 and is inserted into the support block 34. Further, a seal member 34 s is disposed between the support block 34 and the drive shaft 24. The seal member 34 s seals between the inner peripheral surface of the support block 34 and the peripheral surface of the drive shaft 24.

  At the other end of the drive shaft 24, an eccentric shaft 24 a is provided at a position eccentric with respect to the central axis L of the drive shaft 24. The eccentric shaft 24 a revolves around the central axis L by the rotation of the drive shaft 24. A bush 24b is fixed to the eccentric shaft 24a. The bush 24b revolves around the central axis L together with the eccentric shaft 24a. A counterweight 24d is fixed to the bush 24b.

  The expander 12 is fixed to the housing main body 22 so as to face the movable scroll 35 between the support block 34 and the rear housing 23, and the movable scroll 35 rotatably supported by the bush 24 b via the bearing device 24 c. The expander unit 12a as an operation unit including the fixed scroll 36 is provided. The expander unit 12 a is accommodated in an accommodation chamber 12 b defined between the support block 34 and the rear housing 23 in the housing body 22.

  The movable scroll 35 includes a movable substrate 35a having a disk shape supported by the bearing device 24c, and a spiral movable movable spiral wall 35b projecting from the movable substrate 35a. The fixed scroll 36 includes a disk-shaped fixed side substrate 36a, and a spiral fixed side spiral wall 36b protruding from the fixed side substrate 36a toward the movable side substrate 35a. The movable-side spiral wall 35b of the movable scroll 35 and the fixed-side spiral wall 36b of the fixed scroll 36 are meshed with each other to define a working chamber 37 whose volume can be changed.

  A suction port 36c is formed in the center of the fixed side substrate 36a. A suction chamber 38 is defined between the fixed-side substrate 36a and the rear housing 23, and the suction chamber 38 communicates with the working chamber 37 before expansion through a suction port 36c.

  A suction port 39 communicating with the suction chamber 38 is formed in the rear housing 23. Further, a discharge chamber 40 is defined between the inner peripheral surface of the fixed scroll 36 and the outermost peripheral surface of the movable scroll 35. The discharge chamber 40 communicates with a discharge space 41 defined between the support block 34 and the side plate 26 in the housing body 22 through a through hole 34 h of the support block 34. A discharge port 42 communicating with the discharge space 41 is formed in the upper portion of the housing body 22.

  In the present embodiment, the housing 21 of the composite fluid machine 20 serves as both the housing of the pump 11 and the housing of the expander 12. Further, the drive shaft 24 serves as both the pump shaft of the pump 11 and the drive shaft of the expander 12.

  An annular shaft seal member 47 that seals between the lid portion 22 a of the housing body 22 and the drive shaft 24 is accommodated in the housing 21. A shaft seal chamber 46 is defined by the shaft seal member 47, the drive shaft 24, the lid portion 22 a of the housing body 22, and the pump operating unit 30. The shaft seal member 47 is an atmospheric shaft seal that prevents the working fluid in the shaft seal chamber 46 from leaking to the atmosphere side by sealing between the lid portion 22 a of the housing body 22 and the drive shaft 24. The shaft seal chamber 46 is formed in an annular shape so as to surround the drive shaft 24. An annular seal member 48 that seals between the pump chamber 27 and the shaft seal chamber 46 is accommodated in the shaft seal chamber 46.

  One end side of the drive shaft 24 is rotatably supported by the lid portion 22a via a rolling bearing 25, and the other end side of the drive shaft 24 is supported via a rolling bearing 34a provided in the support block 34. The block 34 is rotatably supported. The rolling bearing 25 is disposed on one end side of the drive shaft 24 with respect to the shaft seal chamber 46. That is, the rolling bearing 25 is disposed outside the shaft seal chamber 46.

  The discharge passage 32 (the outlet of the pump 11) is connected to the heat absorber 13a (the inlet of the heat exchanger 13) of the heat exchanger 13 through the first flow path 50a. The heat exchanger 13 includes a heat radiator 13b in addition to the heat absorber 13a. The radiator 13b is provided on an exhaust pipe E1 connected to the vehicle engine E. And the exhaust gas discharged | emitted from the vehicle engine E is thermally radiated with the heat radiator 13b. Therefore, the working fluid discharged from the pump chamber 27 by the operation of the pump operating unit 30 is heated by the exhaust heat from the vehicle engine E by heat exchange between the heat absorber 13a and the heat radiator 13b of the heat exchanger 13. The

  The outlet of the heat absorber 13a of the heat exchanger 13 (the outlet of the heat exchanger 13) is connected to the suction port 39 (the inlet of the expander 12) via the second flow path 50b. The high-temperature and high-pressure working fluid heated and vaporized by the heat exchanger 13 is sucked into the working chamber 37 through the second flow path 50b, the suction port 39, the suction chamber 38, and the suction port 36c. The working fluid sucked into the working chamber 37 expands in the working chamber 37, and a part of the heat quantity of the working fluid is taken out as mechanical energy, and power generation by a generator (not shown), torque assistance of the vehicle engine E, and the like are performed. Done.

  The discharge port 42 (exit of the expander 12) is connected to the inlet of the condenser 14 via the third flow path 50c. The high-temperature and low-pressure working fluid expanded by the expander 12 is discharged to the condenser 14 via the third flow path 50c. The working fluid discharged to the condenser 14 is condensed and liquefied by heat exchange with the outside air.

  The outlet of the condenser 14 is connected to the inlet of the gas-liquid separator 17 via the fourth flow path 50d. The gas-liquid separator 17 is provided with a fourth flow path 50d in a saturated state in which the working fluid condensed and liquefied by the condenser 14 and the working fluid that is not condensed by the condenser 14 and remains in a gaseous state are mixed. Inhaled through. The gas-liquid separator 17 separates the liquefied working fluid from the working fluid in a gas state. The outlet of the gas-liquid separator 17 is connected to the inlet of the supercooler 16 via the fifth flow path 50e. Then, the liquid working fluid separated by the gas-liquid separator 17 is sent to the supercooler 16 via the fifth flow path 50 e and is cooled by the supercooler 16.

  The outlet of the subcooler 16 is connected to the suction passage 31 (the inlet of the pump 11) via the sixth flow path 50f. The low-temperature working fluid cooled by the subcooler 16 is sucked into the pump chamber 27 through the sixth flow path 50 f and the suction path 31. At this time, since the working fluid having a low temperature cooled by the subcooler 16 is sent into the pump chamber 27, the occurrence of cavitation in the pump chamber 27 is suppressed. Then, the working fluid circulates through the working fluid path 15 by the operation of the pump operating unit 30. Therefore, in the Rankine cycle apparatus 10, the working fluid is an array of the expander 12, the condenser 14, the gas-liquid separator 17, the supercooler 16, the pump 11 of the composite fluid machine 20, and the heat exchanger 13 of the composite fluid machine 20. It flows through the circuit along the order.

  A supply passage 51 a that supplies the working fluid to the shaft seal chamber 46 and a discharge passage 51 b that discharges the working fluid in the shaft seal chamber 46 to the working fluid passage 15 are connected to the shaft seal chamber 46. The supply passage 51a is connected to the second flow path 50b (between the outlet of the heat exchanger 13 and the inlet of the expander 12). The supply passage 51a is provided with a throttle portion 51s, and the working fluid flowing through the supply passage 51a is decompressed by the throttle portion 51s. The discharge passage 51b is connected to the third flow path 50c. Therefore, the discharge passage 51 b is connected between the outlet of the expander 12 and the inlet of the pump 11. The supply passage 51a is connected to a portion of the working fluid passage 15 where the pressure is higher than that of the discharge passage 51b.

  An open / close valve 52 is disposed in the discharge passage 51b. The on-off valve 52 is controlled by the control unit 55. Furthermore, the Rankine cycle apparatus 10 includes a pressure sensor 53 as a detection unit that detects a pressure between the outlet of the expander 12 and the inlet of the pump 11. In the present embodiment, the pressure sensor 53 is disposed in the sixth flow path 50f. The pressure sensor 53 is electrically connected to the control unit 55. Information detected by the pressure sensor 53 is sent to the control unit 55.

  The control unit 55 controls the on-off valve 52 so as to close the on-off valve 52 when information indicating that the pressure detected by the pressure sensor 53 has reached a predetermined pressure is sent from the pressure sensor 53. Here, the “predetermined pressure” is a pressure lower than the pressure resistance of the shaft seal member 47 (a limit pressure that the shaft seal member 47 can withstand). In the present embodiment, the “predetermined pressure” is the design pressure of the shaft seal member 47 that is the maximum value of the pressure that can be generated in the normal operation state of the Rankine cycle apparatus 10. In addition, the control unit 55 controls the on-off valve 52 to open the on-off valve 52 when information indicating that the pressure detected by the pressure sensor 53 is lower than a predetermined pressure is sent from the pressure sensor 53. To do.

Next, the operation of the first embodiment will be described.
The shaft seal member 47 is lubricated by the working fluid discharged from the supply passage 51a through the shaft seal chamber 46 to the discharge passage 51b. Further, since the discharge passage 51b is connected between the outlet of the expander 12 and the inlet of the pump 11, the pressure in the shaft seal chamber 46 is between the outlet of the expander 12 and the inlet of the pump 11. Approaching pressure. Therefore, the working fluid in the shaft seal chamber 46 is prevented from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46 and the atmospheric pressure.

  Here, in this embodiment, the throttle part is not provided in the discharge passage 51b. For this reason, by providing the throttle part in the discharge passage 51b, the pressure in the shaft seal chamber 46 is between the pressure on the supply passage 51a side and the pressure between the outlet of the expander 12 and the inlet of the pump 11. There is no such thing as intermediate pressure. Accordingly, it is possible to prevent the pressure in the shaft seal chamber 46 from becoming an intermediate pressure that is always constant and the constant pressure being constantly applied to the shaft seal member 47.

  When the load applied to the vehicle engine E increases due to load fluctuations that occur when the vehicle travels, the temperature of exhaust heat from the vehicle engine E rises. Then, the temperature of the working fluid heat-exchanged with the exhaust heat from the vehicle engine E by the heat exchanger 13 also rises. The higher the temperature of the working fluid, the higher the condensation pressure required to condense and liquefy the working fluid in the condenser 14. As a result, the pressure from the outlet of the expander 12 to the inlet of the pump 11 in the working fluid path 15 increases.

  The control unit 55 controls the on-off valve 52 so as to close the on-off valve 52 when information indicating that the pressure detected by the pressure sensor 53 has reached a predetermined pressure is sent from the pressure sensor 53. As a result, the third flow path 50c and the shaft seal chamber 46 are not in communication, and the pressure in the shaft seal chamber 46 is prevented from becoming higher than a predetermined pressure. As a result, the pressure in the shaft seal chamber 46 exceeds the pressure resistance of the shaft seal member 47, and the shaft seal member 47 cannot seal between the lid portion 22 a of the housing body 22 and the drive shaft 24. This prevents the working fluid in the shaft seal chamber 46 from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46 and the atmospheric pressure.

  And the control part 55 will control the on-off valve 52 so that the on-off valve 52 may be opened, if the information to the effect that the pressure detected by the pressure sensor 53 is less than predetermined pressure is sent from the pressure sensor 53. . Thereby, when the pressure between the outlet of the expander 12 and the inlet of the pump 11 is lower than a predetermined pressure, the third flow path 50c and the shaft seal chamber 46 communicate with each other via the discharge passage 51b. The pressure in the shaft seal chamber 46 approaches the pressure between the outlet of the expander 12 and the inlet of the pump 11. As a result, the working fluid in the shaft seal chamber 46 is prevented from leaking to the atmosphere due to the pressure difference between the pressure in the shaft seal chamber 46 and the atmospheric pressure.

In the first embodiment, the following effects can be obtained.
(1) The Rankine cycle apparatus 10 includes an on-off valve 52 that opens and closes the discharge passage 51b, and a pressure sensor 53 that detects a pressure between the outlet of the expander 12 and the inlet of the pump 11. Further, the Rankine cycle apparatus 10 closes the on-off valve 52 when the pressure sensor 53 detects information that the pressure between the outlet of the expander 12 and the inlet of the pump 11 has reached a predetermined pressure. And a control unit 55 for controlling the on-off valve 52. According to this, the control unit 55 closes the on-off valve 52 when the pressure sensor 53 detects information that the pressure between the outlet of the expander 12 and the inlet of the pump 11 has reached a predetermined pressure. Thus, the on-off valve 52 is controlled. For this reason, the shaft seal chamber 46 is not in communication with the space between the outlet of the expander 12 and the inlet of the pump 11, thereby preventing the pressure in the shaft seal chamber 46 from becoming higher than a predetermined pressure. it can. As a result, the pressure in the shaft seal chamber 46 exceeds the pressure resistance of the shaft seal member 47, and the shaft seal member 47 cannot seal between the lid portion 22 a of the housing body 22 and the drive shaft 24. It is possible to prevent the working fluid in the shaft seal chamber 46 from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46 and the atmospheric pressure.

  (2) The supply passage 51a is connected to a portion of the working fluid passage 15 where the pressure is higher than that of the discharge passage 51b, and the supply passage 51a is provided with a throttle portion 51s. According to this, the flow of the working fluid discharged from the supply passage 51a to the discharge passage 51b through the shaft seal chamber 46 can be made smooth.

  (3) The control unit 55 opens the on-off valve 52 when the pressure sensor 53 detects information that the pressure between the outlet of the expander 12 and the inlet of the pump 11 is lower than a predetermined pressure. Thus, the on-off valve 52 is controlled. According to this, when the pressure between the outlet of the expander 12 and the inlet of the pump 11 is lower than a predetermined pressure, the space between the outlet of the expander 12 and the inlet of the pump 11 and the shaft seal chamber 46 are reduced. Since the communication is made via the discharge passage 51b, the pressure in the shaft seal chamber 46 can be brought close to the pressure between the outlet of the expander 12 and the inlet of the pump 11. As a result, it is possible to prevent the working fluid in the shaft seal chamber 46 from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46 and the atmospheric pressure.

  (4) The pressure sensor 53 detects the pressure between the outlet of the expander 12 and the inlet of the pump 11. According to this, since the control unit 55 controls the on-off valve 52 using information on the pressure between the outlet of the expander 12 and the inlet of the pump 11, the pressure in the shaft seal chamber 46 is a predetermined pressure. It can be made easy to prevent becoming higher.

  (5) A seal member 48 that seals between the pump chamber 27 and the shaft seal chamber 46 is provided between the housing body 22 and the drive shaft 24. According to this, it is possible to prevent the working fluid in the pump chamber 27 from flowing into the shaft seal chamber 46 between the housing body 22 and the drive shaft 24. Therefore, it is possible to prevent the working fluid in the pump chamber 27 from flowing into the shaft seal chamber 46 and increasing the pressure in the shaft seal chamber 46.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the embodiment described below, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the redundant description thereof is omitted or simplified.

  As shown in FIG. 2, the pump 11 and the expander 20A are separate bodies. A housing 21A of the expander 20A is formed of a housing main body 22A having a covered cylindrical shape and a rear housing 23A joined to an opening end of the housing main body 22A. A drive shaft 24A is accommodated in the housing main body 22A.

  A substantially cylindrical support block 34A constituting a part of the housing 21A is fixed in the housing main body 22A. Then, the housing main body 22A is partitioned by the support block 34A into the rear housing 23A side and the lid portion 22a side of the housing main body 22A. The other end side (rear housing 23A side) of the drive shaft 24A is inserted into the support block 34A. The expander portion 12a is accommodated in the accommodating chamber 12b defined between the support block 34 and the rear housing 23A in the housing main body 22.

  An annular shaft seal member 47A that seals between the lid portion 22a of the housing main body 22A and the drive shaft 24A is accommodated in the housing 21A. A shaft seal chamber 46A is defined by the shaft seal member 47A, the drive shaft 24A, and the lid portion 22a of the housing body 22A. The shaft seal member 47A is an atmospheric shaft seal that prevents the working fluid in the shaft seal chamber 46A from leaking to the atmosphere side by sealing between the lid portion 22a of the housing body 22A and the drive shaft 24A. The shaft seal chamber 46A is formed in an annular shape so as to surround the drive shaft 24A. An annular seal member 34s that seals between the storage chamber 12b and the shaft seal chamber 46A is disposed between the support block 34A and the drive shaft 24A.

  The discharge space 41 and the shaft seal chamber 46A communicate with each other via a supply passage 61. The supply passage 61 is provided with an opening adjustment valve 61 v that can adjust the opening of the supply passage 61. The opening adjustment valve 61v is controlled by the control unit 55. The working fluid flowing through the supply passage 61 is decompressed by the opening adjustment valve 61v. Therefore, the opening adjustment valve 61v functions as a throttle part. Further, the shaft seal chamber 46A communicates with the third flow path 50c via the discharge passage 51A.

  The supply passage 61 and the discharge passage 51A are connected to the low pressure side of the working fluid passage 15. The discharge passage 51A is connected to the downstream side in the working fluid flow direction from the portion of the working fluid passage 15 where the supply passage 61 is connected. The pressure in the discharge space 41 to which the supply passage 61 is connected is higher than the pressure in the third passage 50c to which the discharge passage 51A is connected because pressure loss occurs by the amount of the third passage 50c. .

  An open / close valve 52A is disposed in the discharge passage 51A. The on-off valve 52A is controlled by the control unit 55. The control unit 55 sends the information that the pressure detected by the pressure sensor 53 has reached a predetermined pressure from the pressure sensor 53, so that the opening degree adjustment valve 61v and the opening / closing valve 52A are closed. The adjustment valve 61v and the on-off valve 52A are controlled. In addition, the control unit 55 sends information indicating that the pressure detected by the pressure sensor 53 is below a predetermined pressure from the pressure sensor 53, so that the opening adjustment valve 61v and the on-off valve 52A are opened. The opening adjustment valve 61v and the opening / closing valve 52A are controlled.

Next, the operation of the second embodiment will be described.
The shaft seal member 47A is lubricated by the working fluid discharged from the supply passage 61 to the discharge passage 51A through the shaft seal chamber 46A. Further, since the discharge passage 51A is connected between the outlet of the expander 20A and the inlet of the pump 11, the pressure in the shaft seal chamber 46A is increased between the outlet of the expander 20A and the inlet of the pump 11. Approaching pressure. Therefore, the working fluid in the shaft seal chamber 46A is prevented from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46A and the atmospheric pressure.

  The control unit 55 sends the information that the pressure detected by the pressure sensor 53 has reached a predetermined pressure from the pressure sensor 53, so that the opening degree adjustment valve 61v and the opening / closing valve 52A are closed. The adjustment valve 61v and the on-off valve 52A are controlled. As a result, the discharge space 41 and the shaft seal chamber 46A are disconnected from each other, and the third flow path 50c and the shaft seal chamber 46A are disconnected from each other, so that the pressure in the shaft seal chamber 46A becomes higher than a predetermined pressure. Is prevented. As a result, the pressure in the shaft seal chamber 46A exceeds the pressure resistance of the shaft seal member 47A, and the shaft seal member 47A cannot seal between the lid portion 22a of the housing body 22A and the drive shaft 24A. This prevents the working fluid in the shaft seal chamber 46A from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46A and the atmospheric pressure.

  Then, the control unit 55 sends information indicating that the pressure detected by the pressure sensor 53 is lower than the predetermined pressure, so that the opening degree adjusting valve 61v and the opening / closing valve 52A are opened. The opening adjustment valve 61v and the opening / closing valve 52A are controlled. Thereby, when the pressure between the outlet of the expander 12 and the inlet of the pump 11 is lower than a predetermined pressure, the third flow path 50c and the shaft seal chamber 46A communicate with each other via the discharge passage 51A. The pressure in the shaft seal chamber 46A approaches the pressure between the outlet of the expander 20A and the inlet of the pump 11. As a result, the working fluid in the shaft seal chamber 46A is prevented from leaking to the atmosphere due to the differential pressure between the pressure in the shaft seal chamber 46A and the atmospheric pressure.

Therefore, according to the second embodiment, the same effects as the effects (1) to (5) of the first embodiment can be obtained.
In addition, you may change the said embodiment as follows.

  As shown in FIG. 3, in the second embodiment, for example, the second flow path 50b (between the outlet of the heat exchanger 13 and the inlet of the expander 20A) and the shaft seal chamber 46A pass through the supply passage 61A. You may communicate through. A switching valve 62v is disposed in the supply passage 61A. The switching valve 62v is controlled by the control unit 55. The control unit 55 controls the switching valve 62v so as to close the switching valve 62v when information indicating that the pressure detected by the pressure sensor 53 has reached a predetermined pressure is sent from the pressure sensor 53. The supply passage 61A is provided with a throttle portion 61s, and the working fluid flowing through the supply passage 61A is decompressed by the throttle portion 61s. According to this, the working fluid that flows between the outlet of the heat exchanger 13 and the inlet of the expander 20A is supplied to the shaft seal chamber 46A via the supply passage 61A that bypasses the expander 20A. The lubrication oil contained in can improve the lubrication between the shaft seal member 47A and the drive shaft 24A.

  In the embodiment shown in FIG. 3, the switching valve 62v may be deleted. In this case, even if the pressure from the outlet of the expander 12 to the inlet of the pump 11 reaches a predetermined pressure, the working fluid from the second flow path 50b is supplied to the supply passage because the pressure is reduced by the throttle 61s. By flowing into the shaft seal chamber 46A via 61A, the pressure in the shaft seal chamber 46A does not immediately reach a predetermined pressure.

  In the first embodiment, the supply passage 51 a may be connected between the outlet of the heat exchanger 13 and the inlet of the subcooler 16. For example, the supply passage 51 a may be connected to the gas-liquid separator 17. The gas-liquid separator 17 is a saturated state in which the working fluid condensed and liquefied by the condenser 14 is mixed with the working fluid in a gas state without being condensed by the condenser 14. The working fluid can be supplied to the shaft seal chamber 46 via the supply passage 51a. As a result, the shaft seal chamber 46 can be saturated. In the saturated state, if even a little heat is applied, the working fluid becomes a vaporized gas state. Therefore, the working fluid in the sliding portion is saturated by the heat generated by the sliding between the shaft seal member 47 and the drive shaft 24. The state can be changed to a gas state, and the viscosity of the lubricating oil can be prevented from being lowered by mixing the liquid working fluid and the lubricating oil. Since the working fluid cooled and liquefied by the supercooler 16 is in a supercooled state, it cannot be vaporized only by the heat generated by the sliding between the shaft seal member 47 and the drive shaft 24. Therefore, the shaft seal member 47 and the drive shaft 24 are compared with the case where the lubricant between the shaft seal member 47 and the drive shaft 24 is lubricated with the lubricating oil contained in the working fluid cooled and liquefied by the subcooler 16. The lubricating performance between the two can be improved.

  In the first embodiment, the pump 11 and the expander 12 may be separate. In this case, the pump shaft of the pump 11 and the drive shaft of the expander 12 may be used as a single drive shaft, or the pump shaft of the pump 11 and the drive shaft of the expander 12 are provided individually. May be.

  In each of the above embodiments, the pressure sensor 53 is provided at a position where pressure can be detected between the outlet of the expander 12 and 20A and the inlet of the pump 11 and between the on-off valves 52 and 52A. The arrangement location is not particularly limited. For example, when the pressure sensor 53 detects information indicating that the pressure between the outlet of the expander 12, 20A and the opening / closing valves 52, 52A has reached a predetermined pressure, the control unit 55 detects the opening / closing valves 52, 52A. The on-off valves 52 and 52A may be controlled to close the valve.

  In each of the above embodiments, for example, a temperature sensor that detects the temperature of the condenser 14 may be used as the detection unit. The temperature of the condenser 14 is correlated with the condensation pressure. Therefore, for example, the condensing pressure can be detected from the temperature detected by the temperature sensor using a map that associates the temperature of the condenser 14 with the condensing pressure. Thus, the pressure from the outlet of the expander 12 to the inlet of the pump 11 in the working fluid path 15 may be detected using the temperature sensor.

  In each of the above embodiments, the predetermined pressure may be a pressure lower than the pressure resistance of the shaft seal members 47 and 47A (the limit pressure that the shaft seal members 47 and 47A can withstand). For example, the predetermined pressure may be a pressure lower than the design pressure of the shaft seal members 47 and 47A. The predetermined pressure may be a pressure lower than the pressure resistance of the shaft seal members 47 and 47A and higher than the design pressure of the shaft seal members 47 and 47A.

  In each of the above embodiments, the supply passages 51a, 61, 61A are made to have such a diameter that the working fluid flowing through the supply passages 51a, 61, 61A is depressurized. The device itself may function as a throttle unit. According to this, it is not necessary to separately provide the throttle portions 51s and 61s and the opening degree adjusting valve 61v.

  In the second embodiment and the embodiment shown in FIG. 3, a seal member that seals between the discharge space 41 and the shaft seal chamber 46A may be provided between the housing 21A and the drive shaft 24A.

In each of the above embodiments, the pump operating unit 30 may not be configured by the driven gear 28 and the main driving gear 29, and may be a pump operating unit 30 of another form.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.

  (A) A pump, a heat exchanger, an expander, and a condenser are connected in sequence to form a working fluid path through which the working fluid circulates, and a pump chamber is formed in the housing of the pump. Includes a pump shaft extending to the pump chamber, and a pump operating portion that operates in accordance with the rotational drive of the pump shaft is accommodated in the pump chamber. A working fluid circulates in the working fluid path by operation of the working part, and a shaft seal member that seals between the housing and the pump shaft is accommodated in the housing, and the shaft seal member and the pump A shaft seal chamber is defined by the shaft, the housing, and the pump operating portion. The shaft seal chamber includes a supply passage that supplies the working fluid to the shaft seal chamber, and the shaft seal. A discharge passage for discharging the working fluid in the chamber to the working fluid path, and the shaft seal member is lubricated by the working fluid discharged from the supply passage to the discharge passage through the shaft seal chamber, The discharge passage is a Rankine cycle device connected between the outlet of the expander and the inlet of the pump, and includes an on-off valve that opens and closes the discharge passage, and an outlet from the expander to the inlet of the pump. Detecting the pressure between the valve and the on-off valve, and closing the on-off valve when detecting that the pressure detected by the detection unit has reached a predetermined pressure. A Rankine cycle device comprising: a control unit that controls the on-off valve.

  (B) A pump, a heat exchanger, an expander, and a condenser are sequentially connected to form a working fluid path through which the working fluid circulates, and a housing chamber is formed in the housing of the expander. A drive shaft extending into the storage chamber is stored in the storage chamber, and an expander unit that operates in accordance with the rotational drive of the drive shaft is stored in the storage chamber. A shaft seal member that seals between the drive shaft and the shaft seal member, the drive shaft, and the housing is defined by the shaft seal member, and the shaft seal chamber is operated in the shaft seal chamber. A supply passage for supplying fluid and a discharge passage for discharging the working fluid in the shaft seal chamber to the working fluid passage are connected, and discharged from the supply passage to the discharge passage through the shaft seal chamber. The shaft seal member is lubricated by the working fluid, and the discharge passage is a Rankine cycle device connected between the outlet of the expander and the inlet of the pump, and an on-off valve that opens and closes the discharge passage; Detecting a pressure between the outlet of the expander and the inlet of the pump and the on-off valve, and detecting that the pressure detected by the detecting unit has reached a predetermined pressure And a control unit that controls the on-off valve to close the on-off valve when the on-off valve is closed.

  (C) The detection unit is a pressure sensor.

  DESCRIPTION OF SYMBOLS 10 ... Rankine cycle apparatus, 11 ... Pump which is a fluid machine, 12, 20A ... Expander which is a fluid machine, 12a ... Expander part as an operation part, 12b ... Storage chamber, 13 ... Heat exchanger, 14 ... Condenser , 15, working fluid path, 21, 21 A, housing, 24, 24 A, drive shaft, 27, pump chamber as a storage chamber, 30, pump operating portion as an operating portion, 34 s, 48, sealing member, 46, 46 A,. Shaft seal chamber, 47, 47A ... Shaft seal member, 51a, 61, 61A ... Supply passage, 51b, 51A ... Discharge passage, 51s, 61s ... Throttle part, 52, 52A ... Open / close valve, 53 ... Pressure sensor as detection part 55 ... Control part, 61v ... Opening adjustment valve which functions as a throttle part.

Claims (5)

A pump, a heat exchanger, an expander, and a condenser are sequentially connected to form a working fluid path through which a working fluid circulates. The pump and the expander are fluid machines, and the pump that is the fluid machine and A housing chamber is formed in at least one housing of the expander, and a drive shaft extending to the housing chamber is housed in the housing, and the drive chamber is driven by rotation of the drive shaft. An operating portion that operates is housed in the housing, and a shaft seal member that seals between the housing and the drive shaft is housed in the housing. The shaft seal member, the drive shaft, and the housing A shaft seal chamber is defined. In the shaft seal chamber, a supply passage for supplying the working fluid to the shaft seal chamber and a working fluid in the shaft seal chamber are discharged to the working fluid path. The shaft seal member is lubricated by the working fluid discharged from the supply passage to the discharge passage through the shaft seal chamber, and the discharge passage is connected to the pump from the outlet of the expander. Rankine cycle device connected between the entrance and
An on-off valve for opening and closing the discharge passage;
A detector for detecting pressure between the outlet of the expander and the inlet of the pump and the on-off valve;
And a control unit that controls the on-off valve so as to close the on-off valve when detecting that the pressure detected by the detection unit has reached a predetermined pressure. Cycle equipment. The supply passage is connected to a portion of the working fluid passage having a higher pressure than the discharge passage,
The Rankine cycle device according to claim 1, wherein a throttle portion is provided in at least a part of the supply passage.   The said control part controls the said on-off valve so that the said on-off valve may be opened when the information to the effect that the pressure detected by the said detection part is less than predetermined | prescribed pressure is detected. The Rankine cycle apparatus according to claim 1 or claim 2.   The Rankine cycle apparatus according to any one of claims 1 to 3, wherein the detection unit detects a pressure between an outlet of the expander and an inlet of the pump.   The sealing member which seals between the said storage chamber and the said shaft seal chamber is provided between the said housing and the said drive shaft, The any one of Claims 1-4 characterized by the above-mentioned. Rankine cycle apparatus as described in.