JP5494502B2 - Turbine device and waste heat recovery system - Google Patents

Description

  The present invention relates to a turbine apparatus and a waste heat recovery system.

  Conventionally, a Rankine cycle that recovers waste heat associated with the operation of an internal combustion engine is known. In such a Rankine cycle, for example, boiling cooling is performed by using a water cooling cooling system of the engine as a closed structure, and an expander (for example, a steam turbine) is driven by refrigerant vaporized by waste heat in the engine, that is, steam. Some of them recover the thermal energy of the steam by converting it into electrical energy or the like.

  The steam turbine in the Rankine cycle includes a power recovery shaft that transmits the rotational energy of the impeller unit to the power recovery unit. And the lubricating oil for reducing a frictional force is interposed in the bearing part (for example, bearing) of a power recovery shaft (refer FIG. 5). A Rankine cycle system including such a steam turbine is disclosed in, for example, Patent Document 1.

  Further, Patent Documents 2 and 3 disclose other technologies that are considered to be related to the present invention.

JP 2004-2111636 A JP 2010-203347 A Japanese Patent Application Laid-Open No. 08-158876

  In such Rankine cycle system, the higher the pressure ratio defined by the upstream pressure and the downstream pressure of the impeller portion of the steam turbine, the higher the turbine efficiency, that is, the lower the impeller portion pressure. It is known that the turbine efficiency is improved. Therefore, the Rankine cycle system is made highly efficient by managing the turbine chamber housing the impeller part at a lower pressure than the outside. However, if a pressure difference is provided outside and inside the turbine chamber, the lubricating oil present in the bearing portion of the power recovery shaft is sucked into the lower pressure turbine chamber side. Will gradually flow out. When the outflow of such lubricating oil proceeds, the frictional force of the bearing portion of the power recovery shaft gradually increases to lower the turbine efficiency, and in some cases, seizure occurs in the bearing portion.

  This invention is made | formed in view of this point, and it aims at providing the turbine apparatus and waste heat recovery system which can suppress that lubricating oil flows out into the turbine chamber side.

In order to achieve the above object, a turbine apparatus according to the present invention includes an impeller unit that is rotated by the energy of fluid supplied from the outside, and a turbine that houses the impeller unit and is managed at a lower pressure than the external pressure. A power recovery shaft for transmitting the rotation of the chamber and the impeller portion to the outside of the turbine chamber, and a bearing portion for supporting a part of the power recovery shaft between the turbine chamber and the outside via lubricating oil And a sealing portion that seals between the turbine chamber and the bearing portion, and a suppression means that suppresses the lubricant oil existing in the bearing portion from flowing out to the turbine chamber side than the seal portion. The suppression means is a blower blade.
With the above configuration, it is possible to suppress the lubricating oil present in the bearing portion from flowing out to the turbine chamber side by the blower blades.

In particular, in the turbine apparatus of the present invention, the blower blade is provided in the power recovery shaft between the seal portion and the bearing portion, and causes a fluid flow from the seal portion side toward the bearing portion side. It can be configured.
With the above configuration, the blower blade provided on the power recovery shaft between the seal portion and the bearing portion generates a flow of fluid from the seal portion side to the bearing portion side. Movement is suppressed. Therefore, it is possible to prevent the lubricating oil from flowing out to the turbine chamber side.

In the turbine apparatus of the present invention, the blower blade is provided in the power recovery shaft between the impeller portion and the seal portion, and generates a flow of fluid from the turbine chamber side toward the seal portion side. It can be set as the structure made to do.
With the above configuration, the blower blades provided on the power recovery shaft between the impeller portion and the seal portion generate a fluid flow from the turbine chamber side toward the seal portion side, so that the lubricating oil to the turbine chamber side Movement is suppressed. Therefore, it is possible to prevent the lubricating oil from flowing out to the turbine chamber side.

  And this invention is a waste-heat recovery system provided with the turbine apparatus of any one of Claim 1 to 4.

  According to the turbine device and the waste heat recovery system of the present invention, it is possible to prevent the lubricating oil from flowing out to the turbine chamber side.

It is the figure which showed one structural example of the waste heat recovery system of an Example. It is the figure which showed one structural example of the expander of an Example. It is the figure which showed the principal part cross section of the expander of an Example. It is the figure which showed the principal part cross section of the expander of an Example. It is the figure which showed one structural example of the conventional steam turbine.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a waste heat recovery system 1 including a turbine device of the present invention.

  A waste heat recovery system 1 shown in FIG. 1 includes an engine 50 that is cooled by boiling a refrigerant therein. The engine 50 includes a cylinder block 51 and a cylinder head 52. Water jackets 511 and 521 are formed inside the cylinder block 51 and the cylinder head 52, and the engine 50 is cooled by boiling the refrigerant circulating in the water jacket. At this time, the engine 50 generates steam. The engine 50 further includes an exhaust passage 18 that guides exhaust gas generated in the combustion chamber to the outside of the engine 50. One end of a steam passage 3 communicating with the water jackets 511 and 521 is connected to the cylinder head 52 of the engine 50.

  A gas-liquid separator 4 is disposed in the steam passage 3. The gas-liquid separator 4 separates the refrigerant supplied from the water jackets 511 and 521 into vapor that is a vaporized refrigerant and a liquefied refrigerant. That is, the refrigerant that has flowed into the gas-liquid separator 4 in the gas-liquid mixed state from the engine 50 side is separated into the gas phase (vapor) and the liquid phase (liquefied refrigerant) in the gas-liquid separator 4. One end of the refrigerant circulation path 5 is connected to the lower end of the gas-liquid separator 4. The other end of the refrigerant circulation path 5 is connected to a water jacket 511 in the cylinder block 51. Further, a first water pump 6 that pumps the liquefied refrigerant into the engine 50 is disposed in the refrigerant circulation path 5. The first water pump 6 is a so-called mechanical type and uses a crankshaft provided in the engine 50 as a drive source. The first water pump 6 circulates the liquefied refrigerant between the engine 50 and the gas-liquid separator 4.

  A superheater 8 is provided in the steam passage 3. The steam separated in the gas-liquid separator 4 is mainly supplied to the superheater 8. The superheater 8 includes an evaporation unit 8a on the lower side and a superheating unit 8b on the upper side. An exhaust passage 18 is drawn into the superheater 8. Inside the exhaust passage 18, exhaust gas generated by the engine 50 flows. The exhaust passage 18 passes through the superheater 8 so that the exhaust gas passes through the superheater 8b and the evaporator 8a in this order. One end of the liquefied refrigerant passage 7 is connected to the evaporation unit 8a. The exhaust gas exchanges heat with the steam that has passed through the gas-liquid separator 4. The other end of the liquefied refrigerant passage 7 is connected to the lower end of the gas-liquid separator 4. The liquefied refrigerant passage 7 is provided with an on-off valve 7a. The supply state of the liquefied refrigerant from the gas-liquid separator 4 to the evaporation unit 8a is determined by the open / close state of the open / close valve 7a. The liquefied refrigerant supplied to the evaporation unit 8a can be vaporized by the heat of the exhaust gas after the vapor is superheated by the superheating unit 8b. Thereby, while generating amount of steam increases, the superheat degree of steam improves and waste heat recovery efficiency improves. A steam exhaust pipe 3a is provided at the upper end of the superheated part 8b. A nozzle 9 is provided at the tip of the steam discharge pipe 3a.

  An expander 10 which is an embodiment of the turbine apparatus of the present invention is disposed downstream of the steam discharge pipe 3a. The expander 10 is driven by vaporized refrigerant supplied from the superheater 8, that is, steam, and performs energy recovery. The detailed configuration of the expander 10 will be described later.

  The case 101 of the expander 10 includes a discharge port 105 that discharges steam. One end of the steam discharge passage 11 is connected to the discharge port 105. The other end of the steam discharge passage 11 is connected to a capacitor 12. The steam discharge passage 11 introduces the steam discharged from the expander 10 into the condenser 12. The condenser 12 condenses the vapor that has passed through the expander 10 to generate a liquefied refrigerant. The condenser 12 receives the air blown by the fan 13 and can efficiently cool and condense the steam. A condensed water tank 14 for storing the liquefied refrigerant generated in the capacitor 12 is installed below the capacitor 12.

  A liquefied refrigerant passage 15 for recirculating the liquefied refrigerant once stored in the condensed water tank 14 to the engine 50 side is provided on the downstream side of the condensed water tank 14. The liquefied refrigerant passage 15 is connected to the upstream side of the first water pump 6 in the refrigerant circuit 5. A second water pump 16 is disposed in the liquefied refrigerant passage 15. The second water pump 16 is an electric vane pump. When the second water pump 16 is in an operating state, the liquefied refrigerant in the condensed water tank 14 is supplied to the refrigerant circulation path 5. Thereby, the liquefied refrigerant in the condensed water tank 14 can be supplied to the water jacket 511 or the gas-liquid separator 4. The liquefied refrigerant in the condensed water tank 14 can flow into either the water jacket 511 or the gas-liquid separator 4 according to the state of the refrigerant in the water jackets 511 and 521 and the gas-liquid separator 4. A one-way valve 17 for avoiding the back flow of the refrigerant is disposed downstream of the second water pump 16. As described above, the waste heat recovery system 1 includes a path through which the refrigerant circulates.

  Below, the detailed structure of the expander 10 is demonstrated. FIG. 2 is a diagram illustrating a configuration example of the inflator 10 according to the first embodiment. As shown in FIG. 2, the expander 10 is a steam turbine including a case 101 including a turbine chamber 102 and a gear chamber 103 and a turbine 104 housed in the turbine chamber 102 of the case 101. Further, the expander 10 is different from the conventional steam turbine shown in FIG. 5 in that the turbine shaft 106 between the seal portion 108 and the bearing 110 is provided with the blower blades 111.

The nozzle 9 is connected to the turbine chamber 102 of the case 101 so that the steam supplied through the steam passage 3 is injected toward the turbine 104. Thereby, the turbine 104 is rotationally driven by the steam supplied through the steam passage 3. The steam after coming into contact with the turbine 104 is discharged from the discharge port 105 of the turbine chamber 102 to the steam discharge passage 11. The rotational force of the turbine 104 is transmitted to the gear portion 107 accommodated in the gear chamber 103 through the turbine shaft 106 connected to the vicinity of the rotation center of the turbine 104. The gear unit 107 is configured by meshing a plurality of gears having different gear ratios, and after changing the rotation ratio of the turbine 104 transmitted through the turbine shaft 106, transmits it to a generator (not shown) or the like.
The turbine 104 is an example of the configuration of the impeller unit of the present invention. The turbine shaft 106 is an example of the configuration of the power recovery shaft of the present invention.

  A seal portion 108 seals between the turbine chamber 102 and the bearing portion of the turbine shaft 106. Similarly, the gap between the gear chamber 103 and the bearing portion of the turbine shaft 106 is sealed by a seal portion 109. The seal portions 108 and 109 prevent the outside air that has entered the gear chamber 103 from entering the turbine chamber 102. Therefore, the pressure in the turbine chamber 102 can be managed to be lower than the external atmospheric pressure. Therefore, since the turbine 104 can be held at a lower pressure, the pressure ratio defined by the pressure on the upstream side and the pressure on the downstream side of the turbine 104 becomes larger, so that the energy recovery efficiency of the expander 10 is further improved. To do. Further, the seal portions 108 and 109 prevent the vapor supplied from the nozzle 9 from entering the gear chamber 103. Furthermore, the seal part 108 suppresses the lubricating oil of the bearing 110 described later from flowing into the turbine chamber 102.

A bearing 110 is provided at a bearing portion of the turbine shaft 106. The bearing 110 supports a part of the turbine shaft 106 between the seal portions 108 and 109. The bearing 110 is lubricated with lubricating oil for efficiently cooling the frictional heat during rotation while further reducing the frictional force generated when the turbine shaft 106 rotates. That is, the bearing 110 pivotally supports a part of the turbine shaft 106 between the seal portions 108 and 109 via the lubricating oil.
The bearing 110 is a configuration example of the bearing portion of the present invention.

  A detailed configuration of the blower blade 111 will be described. FIG. 3 is a cross-sectional view illustrating a main part of the inflator 10 according to the first embodiment. The blower blade 111 is a plurality of blades provided on the turbine shaft 106 between the seal portion 108 and the bearing 110, and rotates together with the turbine shaft 106. The blower blade 111 is rotatably housed in a housing portion 112 provided between the seal portion 108 and the bearing 110. The blower blade 111 is given a predetermined angle so as to blow a surrounding fluid (gas such as air) toward the bearing 110 when rotating. Thereby, the blower blade 111 generates a predetermined gas flow from the seal portion 108 side, that is, from the turbine chamber 102 side to the bearing 110 side when rotating.

As described above, in order to further improve the energy recovery efficiency of the waste heat recovery system 1, the expander 10 is managed so that the pressure in the turbine chamber 102 is lower than the external pressure. On the other hand, since the pressure other than the turbine chamber 102 (for example, the gear chamber 103 and the bearing portion) is equal to the outside air pressure, a predetermined pressure difference is generated inside the case 101. Therefore, since the lubricating oil present in the bearing 110 provided in the higher pressure bearing portion is sucked to the lower pressure turbine chamber 102 side, it gradually flows out to the turbine chamber 102 side through a slight clearance of the seal portion 108. End up. When the outflow of such lubricating oil proceeds, the frictional force of the bearing 110 gradually increases and the turbine efficiency decreases, and in some cases, the bearing 110 is seized.
Therefore, the expander 10 of the present embodiment is provided with a blower blade 111 that rotates together with the turbine shaft 106 and generates a gas flow from the seal portion 108 side toward the bearing 110 side during rotation. The density of the medium (gas) on the seal portion 108 side is reduced by the gas flow generated when the blower blades 111 are rotated, that is, the pressure on the seal portion 108 side is lowered. The pressure difference from the 110 side becomes smaller. Thus, since the pressure difference before and behind the seal portion 108 can be further reduced, it is possible to suppress the lubricating oil present in the bearing 110 from flowing out to the turbine chamber 102 side.

In this case, it is desirable to set the clearance between the blower blade 111 and the storage portion 112 to be smaller as long as the blower blade 111 can appropriately rotate. In addition, the blower blade 111 is not limited to a configuration in which a plurality of blades are combined, and any configuration that generates a predetermined gas flow from the seal portion 108 side toward the bearing 110 side in conjunction with the rotational motion of the turbine shaft 106. Can be adopted.
The blower blade 111 is an example of the configuration of the suppression means of the present invention.

  As described above, the waste heat recovery system of the present embodiment includes a turbine chamber in which a turbine is housed and managed at a pressure lower than the external pressure, a bearing that supports a part of the turbine shaft via lubricating oil, and a turbine shaft. The pressure difference between the front and rear of the seal portion is caused by the flow of the gas generated when the blower blades are rotated. It can be made smaller. Therefore, it is possible to suppress the lubricating oil present in the bearing from flowing out to the turbine chamber side.

  Next, a second embodiment of the present invention will be described. The waste heat recovery system 2 of the present embodiment has a waste heat recovery system in that it has an expander 20 including a blower blade 211 and a blower guide 212 in the turbine chamber 202 of the case 201 instead of the expander 10. 1 and different.

  The structure of the inflator 20 will be described in detail. FIG. 4 is a cross-sectional view illustrating a main part of the expander 20 according to the second embodiment. In addition, about the component similar to Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

  The expander 20 includes a blower blade 211 and a blower guide 212 in the turbine chamber 202 of the case 201. The blower blades 211 are a plurality of blades provided on the turbine shaft 106 between the turbine 104 and the seal portion 108, and rotate together with the turbine shaft 106. The blower blade 211 is given a predetermined angle so as to blow the surrounding fluid (gas such as air or steam) to the seal portion 108 side (bearing 110 side) during rotation. As a result, the blower blade 211 generates a predetermined gas flow from the turbine chamber 202 side toward the seal portion 108 side, that is, the bearing 110 side when rotating.

  The air blowing guide 212 is provided between the air blowing blade 211 and the seal portion 108. The air blowing guide 212 is inclined in a bowl shape from the air blowing blade 211 side toward the seal portion 108 side, and guides the gas flow generated when the air blowing blade 211 rotates to the clearance portion between the turbine shaft 106 and the sealing portion 108. . The air blowing guide 212 is attached to the wall surface of the turbine chamber 202 on the seal portion 108 side by a plurality of feet, and is configured to allow gas to pass between the feet.

There is a slight clearance between the turbine shaft 106 and the seals 108 and 109 to allow the turbine shaft 106 to rotate properly. Therefore, through a slight clearance between the turbine shaft 106 and the seal portion 108, the lubricating oil present in the bearing 110 provided in the higher pressure bearing portion gradually flows out to the lower pressure turbine chamber 202 side.
Therefore, the expander 20 of the present embodiment is provided with a blower blade 211 that rotates with the turbine shaft 106 and generates a gas flow from the turbine chamber 202 side toward the seal portion 108 side during rotation. The gas flow generated when the blower blade 211 rotates collides with the seal portion 108, and the pressure on the seal portion 108 side is increased by the stagnation point pressure generated by bending the flow direction. Therefore, the pressure difference between the turbine chamber 202 side and the bearing 110 side of the seal portion 108 becomes smaller. Thus, since the pressure difference before and after the seal portion 108 can be further reduced, it is possible to suppress the lubricating oil from moving from the clearance portion between the turbine shaft 106 and the seal portion 108 to the turbine chamber 202 side. That is, it is possible to suppress the lubricating oil from flowing out to the turbine chamber 202 side.
Furthermore, the expander 20 of the present embodiment includes a blower guide 212 that guides a gas flow generated when the blower blade 211 rotates to a clearance portion between the turbine shaft 106 and the seal portion 108. As a result, the pressure difference between the turbine chamber 202 side and the bearing 110 side of the seal portion 108 becomes smaller, so that the lubricating oil moves from the clearance portion between the turbine shaft 106 and the seal portion 108 to the turbine chamber 202 side. It can suppress more appropriately.

In this case, as in the first embodiment, the blower blade 111 is not limited to a configuration in which a plurality of blades are combined, but generates a predetermined gas flow toward the seal portion 108 in conjunction with the rotational movement of the turbine shaft 106. Any configuration can be employed. Moreover, the structure which does not provide the ventilation guide 212 may be sufficient.
The blower blade 211 is an example of the configuration of the suppressing means of the present invention.

  As described above, the waste heat recovery system of the present embodiment includes the blower blade that rotates in the turbine chamber of the case together with the turbine shaft and generates a gas flow from the turbine chamber side toward the seal portion side during rotation. By having the expander, the pressure difference before and after the seal portion can be further reduced by the gas flow generated when the blower blades rotate. Therefore, it can suppress that lubricating oil moves to the turbine chamber side from the clearance part of a turbine shaft and a seal part.

  Furthermore, the expander of the present embodiment further includes a blower guide for guiding the gas flow generated when the blower blades rotate to the clearance portion between the turbine shaft and the seal portion, thereby further reducing the pressure difference before and after the seal portion. Can do. Therefore, it can suppress more appropriately that lubricating oil moves to the turbine chamber side from the clearance part of a turbine shaft and a seal part.

  The above embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to these, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

  For example, the structure which produces the gas flow which goes to a bearing side from a turbine chamber side by rotating independently from rotation of a turbine shaft may be sufficient as a ventilation blade.

  Further, the suppression means of the present invention is not limited to the impeller that rotates, and any configuration that generates a predetermined gas flow from the turbine chamber side toward the bearing side can be employed.

1, 2 Waste heat recovery system 10, 20 Expander (turbine device)
50 Engine 102, 202 Turbine chamber 104 Turbine (impeller)
106 Turbine shaft (power recovery shaft)
108,109 Sealing part 110 Bearing (Bearing part)
111, 211 Blower (Suppression means)
212 Air guide

Claims (4)

An impeller rotating by the energy of fluid supplied from the outside;
A turbine chamber that houses the impeller part and is managed at a pressure lower than an external pressure; and a power recovery shaft that transmits the rotation of the impeller part to the outside of the turbine chamber;
A bearing portion that supports a part of the power recovery shaft between the turbine chamber and the outside via lubricating oil;
A seal portion that seals between the turbine chamber and the bearing portion;
Suppression means for suppressing the lubricant present in the bearing portion from flowing out to the turbine chamber side than the seal portion, and
The turbine device characterized in that the suppression means is a blower blade.   The said blower blade is provided in the said power recovery shaft between the said seal part and the said bearing part, and produces the flow of the fluid which goes to the said bearing part side from the said seal part side. Turbine equipment.   The air blower blade is provided on the power recovery shaft between the impeller part and the seal part, and generates a flow of fluid from the turbine chamber side toward the seal part side. The turbine device described. A waste heat recovery system comprising the turbine device according to any one of claims 1 to 3.

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